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article-131258_29 | Sonography Intestinal Assessment, Protocols, and Interpretation -- Personnel | Intestinal ultrasound is typically performed by: Sonographers Radiologists Gastroenterologists Emergency medicine physicians with specialized ultrasound training | Sonography Intestinal Assessment, Protocols, and Interpretation -- Personnel. Intestinal ultrasound is typically performed by: Sonographers Radiologists Gastroenterologists Emergency medicine physicians with specialized ultrasound training |
article-131258_30 | Sonography Intestinal Assessment, Protocols, and Interpretation -- Preparation | The patient should be fasting for at least 8 to 10 hours. Food can induce gaseous distension, which makes the visualization of the bowel difficult. Ingestion of a large amount of fluid could fill the bowel with water and mimic an intestinal obstruction. Thus, ideally, patients should be fasting for better intestinal visualization. Although fasting is preferable, it is not mandatory when evaluating the acute abdomen. | Sonography Intestinal Assessment, Protocols, and Interpretation -- Preparation. The patient should be fasting for at least 8 to 10 hours. Food can induce gaseous distension, which makes the visualization of the bowel difficult. Ingestion of a large amount of fluid could fill the bowel with water and mimic an intestinal obstruction. Thus, ideally, patients should be fasting for better intestinal visualization. Although fasting is preferable, it is not mandatory when evaluating the acute abdomen. |
article-131258_31 | Sonography Intestinal Assessment, Protocols, and Interpretation -- Technique or Treatment -- The Sequence of Intestinal Ultrasound Examination | In chronic conditions: as ulcerative colitis, Crohn disease follow-up, celiac disease, etc., it is preferred to start from the epigastric region or the left iliac (sigmoid) quadrant and then proceed to examine the rest of the intestine and colon, including the terminal ileum and appendix in the right iliac quadrant. While the sequential search patterns can differ depending on operator training, a consistent search pattern helps avoid missed diagnoses. In acute conditions : In the setting of an acute abdomen, the examiner should start with the abdominal quadrant most tender as directed by the patient. | Sonography Intestinal Assessment, Protocols, and Interpretation -- Technique or Treatment -- The Sequence of Intestinal Ultrasound Examination. In chronic conditions: as ulcerative colitis, Crohn disease follow-up, celiac disease, etc., it is preferred to start from the epigastric region or the left iliac (sigmoid) quadrant and then proceed to examine the rest of the intestine and colon, including the terminal ileum and appendix in the right iliac quadrant. While the sequential search patterns can differ depending on operator training, a consistent search pattern helps avoid missed diagnoses. In acute conditions : In the setting of an acute abdomen, the examiner should start with the abdominal quadrant most tender as directed by the patient. |
article-131258_32 | Sonography Intestinal Assessment, Protocols, and Interpretation -- Technique or Treatment -- Limitations | If the intestinal visualization is not possible due to gaseous distension, then " graded compression " of the bowel will help shift gaseous shadows and improve image quality. Another maneuver is to turn the patient on their side (right or left according to the bowel examined), assisting in displacing visually obstructing gas. | Sonography Intestinal Assessment, Protocols, and Interpretation -- Technique or Treatment -- Limitations. If the intestinal visualization is not possible due to gaseous distension, then " graded compression " of the bowel will help shift gaseous shadows and improve image quality. Another maneuver is to turn the patient on their side (right or left according to the bowel examined), assisting in displacing visually obstructing gas. |
article-131258_33 | Sonography Intestinal Assessment, Protocols, and Interpretation -- Complications | There are no complications to this non-invasive procedure. | Sonography Intestinal Assessment, Protocols, and Interpretation -- Complications. There are no complications to this non-invasive procedure. |
article-131258_34 | Sonography Intestinal Assessment, Protocols, and Interpretation -- Clinical Significance -- The Impact of Intestinal Ultrasound on the Medical Care of Inflammatory Bowel Disease | Intestinal ultrasound could be used to diagnose multiple gastrointestinal diseases (acute and chronic). [30] [31] [25] Inflammatory bowel diseases could be diagnosed and followed up by intestinal ultrasound, as these patients need close monitoring and follow-up. Using a cost-effective, non-invasive method with no radiological hazard such as intestinal ultrasound is greatly beneficial to the patients. | Sonography Intestinal Assessment, Protocols, and Interpretation -- Clinical Significance -- The Impact of Intestinal Ultrasound on the Medical Care of Inflammatory Bowel Disease. Intestinal ultrasound could be used to diagnose multiple gastrointestinal diseases (acute and chronic). [30] [31] [25] Inflammatory bowel diseases could be diagnosed and followed up by intestinal ultrasound, as these patients need close monitoring and follow-up. Using a cost-effective, non-invasive method with no radiological hazard such as intestinal ultrasound is greatly beneficial to the patients. |
article-131258_35 | Sonography Intestinal Assessment, Protocols, and Interpretation -- Enhancing Healthcare Team Outcomes | Intestinal ultrasound as a part of the follow-up for patients with inflammatory bowel diseases (Crohn disease and ulcerative colitis) has an important role, especially when performed by a trained operator. It can decrease the need for repeated CT or MR imaging of the abdomen. An interprofessional team approach in which family clinicians, specialists, nurses, mid-level practitioners, and ultrasound techs exercise open communication regarding conducting the examination and the findings that result can help the team guide patient care leading to better outcomes. [Level 5] | Sonography Intestinal Assessment, Protocols, and Interpretation -- Enhancing Healthcare Team Outcomes. Intestinal ultrasound as a part of the follow-up for patients with inflammatory bowel diseases (Crohn disease and ulcerative colitis) has an important role, especially when performed by a trained operator. It can decrease the need for repeated CT or MR imaging of the abdomen. An interprofessional team approach in which family clinicians, specialists, nurses, mid-level practitioners, and ultrasound techs exercise open communication regarding conducting the examination and the findings that result can help the team guide patient care leading to better outcomes. [Level 5] |
article-131258_36 | Sonography Intestinal Assessment, Protocols, and Interpretation -- Review Questions | Access free multiple choice questions on this topic. Comment on this article. | Sonography Intestinal Assessment, Protocols, and Interpretation -- Review Questions. Access free multiple choice questions on this topic. Comment on this article. |
article-27694_0 | Pressure Support -- Continuing Education Activity | Ventilation management is a crucial aspect of critical care medicine, serving as a cornerstone in emergency, internal, and hospital medicine. Several ventilation modes exist that are important for patient care in inpatient settings and for immediate stabilization. Pressure support ventilation (PSV) is a mode designed to maintain spontaneous breathing in patients with both acute and chronic requirements. PSV is characterized by patient-triggered, pressure-limited, flow-cycled breaths, and each breath is supplemented with a consistent positive pressure. Evidence-based practice emphasizes the role of pressure support mode in liberating patients from mechanical ventilation. | Pressure Support -- Continuing Education Activity. Ventilation management is a crucial aspect of critical care medicine, serving as a cornerstone in emergency, internal, and hospital medicine. Several ventilation modes exist that are important for patient care in inpatient settings and for immediate stabilization. Pressure support ventilation (PSV) is a mode designed to maintain spontaneous breathing in patients with both acute and chronic requirements. PSV is characterized by patient-triggered, pressure-limited, flow-cycled breaths, and each breath is supplemented with a consistent positive pressure. Evidence-based practice emphasizes the role of pressure support mode in liberating patients from mechanical ventilation. |
article-27694_1 | Pressure Support -- Continuing Education Activity | PSV operates as a flow-limited ventilation mode, providing pressure during inspiration until a preset flow threshold is attained. The inspiratory pressure level can vary from 5 to 20 cm H 2 O, depending on the patient's ventilatory needs. A pressure support of less than 5 cm H 2 O reduces resistance by overcoming ventilator dead space, including the circuitry and its components. Increased pressure support levels are introduced to alleviate the work of breathing (WOB) by supplementing the patient's spontaneous effort with positive pressure. When using pressure support levels between 10 and 12 mL/kg, the ventilator takes over all the WOB. Patients consistently govern breath frequency, duration, and flow in a PSV environment. The volume of each breath is directly influenced by set pressures, patient effort, and other mechanical settings that may counteract ventilation. This activity delineates the indications, contraindications, and clinical benefits of utilizing pressure support in ventilated patients to resume spontaneous breathing. | Pressure Support -- Continuing Education Activity. PSV operates as a flow-limited ventilation mode, providing pressure during inspiration until a preset flow threshold is attained. The inspiratory pressure level can vary from 5 to 20 cm H 2 O, depending on the patient's ventilatory needs. A pressure support of less than 5 cm H 2 O reduces resistance by overcoming ventilator dead space, including the circuitry and its components. Increased pressure support levels are introduced to alleviate the work of breathing (WOB) by supplementing the patient's spontaneous effort with positive pressure. When using pressure support levels between 10 and 12 mL/kg, the ventilator takes over all the WOB. Patients consistently govern breath frequency, duration, and flow in a PSV environment. The volume of each breath is directly influenced by set pressures, patient effort, and other mechanical settings that may counteract ventilation. This activity delineates the indications, contraindications, and clinical benefits of utilizing pressure support in ventilated patients to resume spontaneous breathing. |
article-27694_2 | Pressure Support -- Continuing Education Activity | Objectives: Identify appropriate patient populations for pressure support ventilation based on clinical indicators and ventilatory needs. Implement optimal pressure support ventilation settings considering tube size, lung compliance, and airway resistance. Apply evidence-based practices in pressure support ventilation to enhance weaning strategies and improve patient outcomes. Coordinate interprofessional efforts in the comprehensive management of patients on pressure support ventilation, fostering a holistic approach to critical care. Access free multiple choice questions on this topic. | Pressure Support -- Continuing Education Activity. Objectives: Identify appropriate patient populations for pressure support ventilation based on clinical indicators and ventilatory needs. Implement optimal pressure support ventilation settings considering tube size, lung compliance, and airway resistance. Apply evidence-based practices in pressure support ventilation to enhance weaning strategies and improve patient outcomes. Coordinate interprofessional efforts in the comprehensive management of patients on pressure support ventilation, fostering a holistic approach to critical care. Access free multiple choice questions on this topic. |
article-27694_3 | Pressure Support -- Introduction | Ventilation management is a crucial aspect of critical care medicine, serving as a cornerstone in emergency, internal, and hospital medicine. Several ventilation modes exist that are important for patient care in inpatient settings and for immediate stabilization. Pressure support ventilation (PSV) is a ventilation mode designed to maintain spontaneous breathing in patients with both acute and chronic requirements. [1] PSV is characterized by patient-triggered, pressure-limited, flow-cycled breaths, and each breath is supplemented with a consistent positive pressure. Evidence-based practice emphasizes the role of pressure support mode in liberating patients from mechanical ventilation. The amount of ventilation depends on lung compliance and the drive to breathe. | Pressure Support -- Introduction. Ventilation management is a crucial aspect of critical care medicine, serving as a cornerstone in emergency, internal, and hospital medicine. Several ventilation modes exist that are important for patient care in inpatient settings and for immediate stabilization. Pressure support ventilation (PSV) is a ventilation mode designed to maintain spontaneous breathing in patients with both acute and chronic requirements. [1] PSV is characterized by patient-triggered, pressure-limited, flow-cycled breaths, and each breath is supplemented with a consistent positive pressure. Evidence-based practice emphasizes the role of pressure support mode in liberating patients from mechanical ventilation. The amount of ventilation depends on lung compliance and the drive to breathe. |
article-27694_4 | Pressure Support -- Introduction | PSV operates as a flow-limited ventilation mode, providing pressure during inspiration until a preset flow threshold is attained. The inspiratory pressure level can vary from 5 to 20 cm H 2 O, depending on the patient's ventilatory needs. Pressure support at low levels, typically less than 5 cm H 2 O, is commonly used to overcome airway resistance arising from ventilator accessories, including the circuitry and its components, and this resistance is inversely related to the tube diameter. Additional important settings, such as inspiratory rise times, respiratory rate, fraction of inspired oxygen (FiO 2 ), and positive end-expiratory pressure (PEEP), were included. [2] | Pressure Support -- Introduction. PSV operates as a flow-limited ventilation mode, providing pressure during inspiration until a preset flow threshold is attained. The inspiratory pressure level can vary from 5 to 20 cm H 2 O, depending on the patient's ventilatory needs. Pressure support at low levels, typically less than 5 cm H 2 O, is commonly used to overcome airway resistance arising from ventilator accessories, including the circuitry and its components, and this resistance is inversely related to the tube diameter. Additional important settings, such as inspiratory rise times, respiratory rate, fraction of inspired oxygen (FiO 2 ), and positive end-expiratory pressure (PEEP), were included. [2] |
article-27694_5 | Pressure Support -- Introduction | Higher levels of pressure support are used to help patients breathe easier by introducing positive pressure to supplement their spontaneous effort. PSV can be used as a stand-alone ventilation mode or as a weaning mode from mechanical ventilation. In addition, it can be used as a noninvasive ventilation (NIV) mode in the intensive care unit (ICU) for selected cases that do not require intubation or post-extubation hypercapnic respiratory failure. [3] [4] | Pressure Support -- Introduction. Higher levels of pressure support are used to help patients breathe easier by introducing positive pressure to supplement their spontaneous effort. PSV can be used as a stand-alone ventilation mode or as a weaning mode from mechanical ventilation. In addition, it can be used as a noninvasive ventilation (NIV) mode in the intensive care unit (ICU) for selected cases that do not require intubation or post-extubation hypercapnic respiratory failure. [3] [4] |
article-27694_6 | Pressure Support -- Introduction | Patients consistently govern breath frequency, duration, and flow in a PSV environment. The volume of each breath is directly influenced by set pressures, patient effort, and other mechanical settings that may oppose ventilation. [5] [6] [7] | Pressure Support -- Introduction. Patients consistently govern breath frequency, duration, and flow in a PSV environment. The volume of each breath is directly influenced by set pressures, patient effort, and other mechanical settings that may oppose ventilation. [5] [6] [7] |
article-27694_7 | Pressure Support -- Function | The PSV mode is often used in spontaneously breathing patients to aid ventilator liberation. This mode is comfortable for weaning patients and can be readily titrated to regulate a patient's breathing. In addition, PSV may be initiated in patients without the intention of ventilation liberation. Patient populations requiring long-term mechanical ventilation, such as those with small artificial airways, chronic obstructive pulmonary disease (COPD), and chronic muscle weakness, may benefit from pressure support mode. | Pressure Support -- Function. The PSV mode is often used in spontaneously breathing patients to aid ventilator liberation. This mode is comfortable for weaning patients and can be readily titrated to regulate a patient's breathing. In addition, PSV may be initiated in patients without the intention of ventilation liberation. Patient populations requiring long-term mechanical ventilation, such as those with small artificial airways, chronic obstructive pulmonary disease (COPD), and chronic muscle weakness, may benefit from pressure support mode. |
article-27694_8 | Pressure Support -- Function | In certain aspects, PSV shares similarities with intermittent positive-pressure breathing (IPPB). Similar to pressure support, an IPPB support device is used to enhance the quality of breaths by promoting lung expansion. The concept of lung expansion therapy is that the elevation of alveolar pressure (positive pressure) during lung expansion raises the transpulmonary pressure gradient by increasing the pressure within the alveoli. This mechanism of action lowers the partial pressure of carbon dioxide in the blood, decreases the risk of pneumonia, and increases overall pulmonary function. | Pressure Support -- Function. In certain aspects, PSV shares similarities with intermittent positive-pressure breathing (IPPB). Similar to pressure support, an IPPB support device is used to enhance the quality of breaths by promoting lung expansion. The concept of lung expansion therapy is that the elevation of alveolar pressure (positive pressure) during lung expansion raises the transpulmonary pressure gradient by increasing the pressure within the alveoli. This mechanism of action lowers the partial pressure of carbon dioxide in the blood, decreases the risk of pneumonia, and increases overall pulmonary function. |
article-27694_9 | Pressure Support -- Function | The concept of pressure support is straightforward and logical, as elevating the pressure support leads to increased ventilation and reduced carbon dioxide levels in the blood. Lung compliance, airway resistance, and patient synchrony significantly influence the success of PSV. An increase in airway resistance or a decrease in lung compliance can lead to an outcome in PSV that falls short of the desired goal. When PSV is used as an NIV mode in the ICU, the settings differ from home NIV as inspiratory pressure is the sum of pressure support and PEEP. In contrast, expiratory pressure is equal to PEEP. [8] | Pressure Support -- Function. The concept of pressure support is straightforward and logical, as elevating the pressure support leads to increased ventilation and reduced carbon dioxide levels in the blood. Lung compliance, airway resistance, and patient synchrony significantly influence the success of PSV. An increase in airway resistance or a decrease in lung compliance can lead to an outcome in PSV that falls short of the desired goal. When PSV is used as an NIV mode in the ICU, the settings differ from home NIV as inspiratory pressure is the sum of pressure support and PEEP. In contrast, expiratory pressure is equal to PEEP. [8] |
article-27694_10 | Pressure Support -- Function | As previously noted, PSV is exclusively a spontaneous mode, requiring patients to initiate breaths. Apneic patients must be in a controlled breath environment where the ventilator may fully sustain respiratory function. A patient must be hemodynamically stable and have sufficient respiratory effort to qualify for pressure support mode. However, a patient with a significant acid-base abnormality, a higher PEEP requirement (8 and above), and an FiO 2 of 50% or more in a controlled setting should not be considered for pressure support mode. [9] [10] [11] | Pressure Support -- Function. As previously noted, PSV is exclusively a spontaneous mode, requiring patients to initiate breaths. Apneic patients must be in a controlled breath environment where the ventilator may fully sustain respiratory function. A patient must be hemodynamically stable and have sufficient respiratory effort to qualify for pressure support mode. However, a patient with a significant acid-base abnormality, a higher PEEP requirement (8 and above), and an FiO 2 of 50% or more in a controlled setting should not be considered for pressure support mode. [9] [10] [11] |
article-27694_11 | Pressure Support -- Function | Numerous limitations for PSV extend beyond liberations from mechanical ventilation. The ideal level of pressure support for weaning may vary among patients depending on the tube size and lung compliance. In addition, prolonged periods of PSV use may lead to diaphragm weakness, delayed mechanical ventilation duration, and increased mortality. [12] [13] [14] Moreover, PSV can induce patient-ventilator asynchrony due to misalignment between patient effort and the pressure delivered by the mechanical ventilator in PSV mode. [15] When patient-ventilator asynchrony is noted, addressing the issue of ineffective triggering causing the asynchrony can be achieved by reducing cycle time or adjusting the level of pressure support. [15] | Pressure Support -- Function. Numerous limitations for PSV extend beyond liberations from mechanical ventilation. The ideal level of pressure support for weaning may vary among patients depending on the tube size and lung compliance. In addition, prolonged periods of PSV use may lead to diaphragm weakness, delayed mechanical ventilation duration, and increased mortality. [12] [13] [14] Moreover, PSV can induce patient-ventilator asynchrony due to misalignment between patient effort and the pressure delivered by the mechanical ventilator in PSV mode. [15] When patient-ventilator asynchrony is noted, addressing the issue of ineffective triggering causing the asynchrony can be achieved by reducing cycle time or adjusting the level of pressure support. [15] |
article-27694_12 | Pressure Support -- Issues of Concern | A simple approach to understanding the impact of resistance and compliance on outcomes is by comparing 2 medical conditions using the same fictitious patient, which could prompt the initiation of PSV. One can then speculate how each scenario might respond to treatment. In the initial scenario, we consider a fictional post-surgical patient undergoing weaning from mechanical ventilation in pressure support mode. The posteroanterior x-ray reveals no notable abnormalities. Lung compliance, calculated at 80 mL/cm H 2 O, falls within the normal range, and arterial blood gases depict normocarbia. | Pressure Support -- Issues of Concern. A simple approach to understanding the impact of resistance and compliance on outcomes is by comparing 2 medical conditions using the same fictitious patient, which could prompt the initiation of PSV. One can then speculate how each scenario might respond to treatment. In the initial scenario, we consider a fictional post-surgical patient undergoing weaning from mechanical ventilation in pressure support mode. The posteroanterior x-ray reveals no notable abnormalities. Lung compliance, calculated at 80 mL/cm H 2 O, falls within the normal range, and arterial blood gases depict normocarbia. |
article-27694_13 | Pressure Support -- Issues of Concern | The patient's ventilator is currently set with pressure support of 10 cm H 2 O, yielding an average exhaled tidal volume of 550 mL. In comparison, in the second scenario, the patient's diagnosis shifts to postoperative pneumonia. Although the patient's condition has improved, they are initiated on pressure support mode ventilation at 10 cm H 2 O to aid in the weaning process. A posteroanterior x-ray reveals fibrosis as a consequence of pneumonia. Based on blood gas results, lung compliance is calculated at 35 mL/cm H 2 O, indicating low lung compliance with slight hypercarbia. The patient exhibits an exhaled tidal volume of 300 mL, contrasting with the 550 mL observed in the earlier scenario. Based on this hypothesis, one may reasonably infer that the outcomes of PSV are intricately linked to the patient's underlying diagnosis. [10] | Pressure Support -- Issues of Concern. The patient's ventilator is currently set with pressure support of 10 cm H 2 O, yielding an average exhaled tidal volume of 550 mL. In comparison, in the second scenario, the patient's diagnosis shifts to postoperative pneumonia. Although the patient's condition has improved, they are initiated on pressure support mode ventilation at 10 cm H 2 O to aid in the weaning process. A posteroanterior x-ray reveals fibrosis as a consequence of pneumonia. Based on blood gas results, lung compliance is calculated at 35 mL/cm H 2 O, indicating low lung compliance with slight hypercarbia. The patient exhibits an exhaled tidal volume of 300 mL, contrasting with the 550 mL observed in the earlier scenario. Based on this hypothesis, one may reasonably infer that the outcomes of PSV are intricately linked to the patient's underlying diagnosis. [10] |
article-27694_14 | Pressure Support -- Issues of Concern | PSV emerges as a pivotal weaning strategy when compared to IMV modes. Studies have shown that PSV leads to a reduced respiratory rate, increased tidal volume, diminished respiratory muscle activity, and lower oxygen consumption compared to IMV ventilation modes. In 2000, an article from the United States National Library of Medicine noted the benefits of utilizing pressure support to wean patients. [16] The report states that while a 2-hour duration has been extensively evaluated, similar weaning outcomes are achievable with a reduced duration of 30 minutes. A gradual withdrawal of ventilator support is recommended for patients failing the initial spontaneous breathing trial. | Pressure Support -- Issues of Concern. PSV emerges as a pivotal weaning strategy when compared to IMV modes. Studies have shown that PSV leads to a reduced respiratory rate, increased tidal volume, diminished respiratory muscle activity, and lower oxygen consumption compared to IMV ventilation modes. In 2000, an article from the United States National Library of Medicine noted the benefits of utilizing pressure support to wean patients. [16] The report states that while a 2-hour duration has been extensively evaluated, similar weaning outcomes are achievable with a reduced duration of 30 minutes. A gradual withdrawal of ventilator support is recommended for patients failing the initial spontaneous breathing trial. |
article-27694_15 | Pressure Support -- Issues of Concern | Comparing various weaning methods, such as T-piece and trach collar trials, for liberating patients from the ventilator is crucial. Studies indicate higher success rates when utilizing pressure support for spontaneous breathing trials than T-piece trials for a simple wean. T-piece trials are noted to have a less successful outcome partially due to the absence of pressure equalization provided by pressure support, leaving the patient reliant solely on their ability to overcome the endotracheal tube's resistance. | Pressure Support -- Issues of Concern. Comparing various weaning methods, such as T-piece and trach collar trials, for liberating patients from the ventilator is crucial. Studies indicate higher success rates when utilizing pressure support for spontaneous breathing trials than T-piece trials for a simple wean. T-piece trials are noted to have a less successful outcome partially due to the absence of pressure equalization provided by pressure support, leaving the patient reliant solely on their ability to overcome the endotracheal tube's resistance. |
article-27694_16 | Pressure Support -- Issues of Concern | In a significant 2019 trial published in JAMA, a comparison was made between 30 minutes of pressure support and 2 hours of T-piece weaning. Among the 1153 adults studied, the proportion of successfully extubated patients was 82.3% ( n =557) in the 30-minute PSV group, whereas 74% ( n =578) in the 2-hour T-piece ventilation group, which is a statistically significant difference. [17] | Pressure Support -- Issues of Concern. In a significant 2019 trial published in JAMA, a comparison was made between 30 minutes of pressure support and 2 hours of T-piece weaning. Among the 1153 adults studied, the proportion of successfully extubated patients was 82.3% ( n =557) in the 30-minute PSV group, whereas 74% ( n =578) in the 2-hour T-piece ventilation group, which is a statistically significant difference. [17] |
article-27694_17 | Pressure Support -- Issues of Concern | The endotracheal tube, being smaller than natural airways, remains static, whereas the natural airway is dynamic and dilates during inspiration. This understanding underscores how an artificial static airway can pose a disadvantage when breathing spontaneously without pressure compensation. [18] | Pressure Support -- Issues of Concern. The endotracheal tube, being smaller than natural airways, remains static, whereas the natural airway is dynamic and dilates during inspiration. This understanding underscores how an artificial static airway can pose a disadvantage when breathing spontaneously without pressure compensation. [18] |
article-27694_18 | Pressure Support -- Issues of Concern | One of the newer modes available in certain ventilator brands is adaptive support ventilation, characterized as volume-targeted PSV. In this mode, the machine dynamically adjusts respiratory rate, tidal volume, and inspiratory time in response to the patient's effort and respiratory mechanics. | Pressure Support -- Issues of Concern. One of the newer modes available in certain ventilator brands is adaptive support ventilation, characterized as volume-targeted PSV. In this mode, the machine dynamically adjusts respiratory rate, tidal volume, and inspiratory time in response to the patient's effort and respiratory mechanics. |
article-27694_19 | Pressure Support -- Issues of Concern | Patient-centered weaning is important when utilizing pressure support as the primary ventilation mode. Recognizing the uniqueness of each individual will often determine the outcome of ventilation liberation. A ventilator liberation protocol that allows for an individualized approach yields superior results compared to a one-size-fits-all approach. Increased pressure support levels are introduced to alleviate the work of breathing (WOB) by supplementing a patient's spontaneous effort with positive pressure. Instituting a pressure support level that stabilizes patients' WOB is valuable in determining a baseline point for ventilation. A gradual, slow withdrawal to enhance muscle strength and endurance leads to more favorable outcomes than weaning modes, such as IMV. When using pressure support levels between 10 and 12 mL/kg, the ventilator takes over all the WOB. | Pressure Support -- Issues of Concern. Patient-centered weaning is important when utilizing pressure support as the primary ventilation mode. Recognizing the uniqueness of each individual will often determine the outcome of ventilation liberation. A ventilator liberation protocol that allows for an individualized approach yields superior results compared to a one-size-fits-all approach. Increased pressure support levels are introduced to alleviate the work of breathing (WOB) by supplementing a patient's spontaneous effort with positive pressure. Instituting a pressure support level that stabilizes patients' WOB is valuable in determining a baseline point for ventilation. A gradual, slow withdrawal to enhance muscle strength and endurance leads to more favorable outcomes than weaning modes, such as IMV. When using pressure support levels between 10 and 12 mL/kg, the ventilator takes over all the WOB. |
article-27694_20 | Pressure Support -- Issues of Concern | Understanding when to discontinue pressure support is just as important as when to initiate it. When transitioning a patient from a breath rate-controlled mode to pressure support, monitoring their responsiveness to therapy becomes imperative. Assessing the rapid shallow breathing index (RSBI) is a valuable indicator of responsiveness. This calculation is straightforward: the patient's respiratory rate is divided by the average tidal volume in liters (L). If the resulting number exceeds 105, weaning failure is virtually guaranteed. This quotient indicates that the patient is exhaling small tidal volumes at a high frequency, indicating respiratory distress and a potential struggle. | Pressure Support -- Issues of Concern. Understanding when to discontinue pressure support is just as important as when to initiate it. When transitioning a patient from a breath rate-controlled mode to pressure support, monitoring their responsiveness to therapy becomes imperative. Assessing the rapid shallow breathing index (RSBI) is a valuable indicator of responsiveness. This calculation is straightforward: the patient's respiratory rate is divided by the average tidal volume in liters (L). If the resulting number exceeds 105, weaning failure is virtually guaranteed. This quotient indicates that the patient is exhaling small tidal volumes at a high frequency, indicating respiratory distress and a potential struggle. |
article-27694_21 | Pressure Support -- Issues of Concern | Many other factors play a role when pressure support is unsuccessful. Underlying issues such as congestive heart failure, chronic pulmonary disease, fluid overload, dehydration, or electrolyte abnormalities leading to hemodynamic compromise can all contribute to unsuccessful outcomes. Very low blood pressure may stem from hypovolemia or potential sepsis, whereas high blood pressure could result from cardiac or systemic conditions or the patient's distress due to intolerance of their spontaneous breathing efforts. | Pressure Support -- Issues of Concern. Many other factors play a role when pressure support is unsuccessful. Underlying issues such as congestive heart failure, chronic pulmonary disease, fluid overload, dehydration, or electrolyte abnormalities leading to hemodynamic compromise can all contribute to unsuccessful outcomes. Very low blood pressure may stem from hypovolemia or potential sepsis, whereas high blood pressure could result from cardiac or systemic conditions or the patient's distress due to intolerance of their spontaneous breathing efforts. |
article-27694_22 | Pressure Support -- Issues of Concern | The patient's presentation during the process can identify success in pressure support weaning. Monitoring the RSBI and vital signs is a good indicator of patient tolerance. Although arterial blood gasses may be drawn to determine tolerance, studies do not significantly reflect that an arterial blood gas altered the decision to extubate. [19] | Pressure Support -- Issues of Concern. The patient's presentation during the process can identify success in pressure support weaning. Monitoring the RSBI and vital signs is a good indicator of patient tolerance. Although arterial blood gasses may be drawn to determine tolerance, studies do not significantly reflect that an arterial blood gas altered the decision to extubate. [19] |
article-27694_23 | Pressure Support -- Issues of Concern | Systemic steroids yield favorable outcomes for individuals undergoing mechanical ventilation weaning. Administering steroids both before and after extubation proves beneficial in preventing upper airway obstruction and reducing the risk of reintubation, particularly in at-risk populations. | Pressure Support -- Issues of Concern. Systemic steroids yield favorable outcomes for individuals undergoing mechanical ventilation weaning. Administering steroids both before and after extubation proves beneficial in preventing upper airway obstruction and reducing the risk of reintubation, particularly in at-risk populations. |
article-27694_24 | Pressure Support -- Issues of Concern | After extubation, vigilant patient monitoring and proactive measures to mitigate the risk of reintubation are crucial for success. A study suggests that visually assessing the extubated patient and implementing noninvasive positive pressure ventilation through a mask can significantly decrease the risk of reintubation, especially for patients with chronic lung disease. Allowing a smooth transition from an artificial airway on pressure support mode to noninvasive bi-level pressure assistance enhances positive outcomes in the weaning process. [20] [6] [16] [21] [7] | Pressure Support -- Issues of Concern. After extubation, vigilant patient monitoring and proactive measures to mitigate the risk of reintubation are crucial for success. A study suggests that visually assessing the extubated patient and implementing noninvasive positive pressure ventilation through a mask can significantly decrease the risk of reintubation, especially for patients with chronic lung disease. Allowing a smooth transition from an artificial airway on pressure support mode to noninvasive bi-level pressure assistance enhances positive outcomes in the weaning process. [20] [6] [16] [21] [7] |
article-27694_25 | Pressure Support -- Issues of Concern | Managing PSV in cases of COPD and asthma can be challenging due to substantial variability among patients and varying airway resistance. Furthermore, other factors should be considered, such as expiratory and inspiratory time, airway resistance, lung compliance, and WOB. [22] The use of PSV can cause a decrease in CO 2 levels, which can induce central apneas, especially in susceptible patients with spinal cord injury and heart failure. [23] [24] [25] | Pressure Support -- Issues of Concern. Managing PSV in cases of COPD and asthma can be challenging due to substantial variability among patients and varying airway resistance. Furthermore, other factors should be considered, such as expiratory and inspiratory time, airway resistance, lung compliance, and WOB. [22] The use of PSV can cause a decrease in CO 2 levels, which can induce central apneas, especially in susceptible patients with spinal cord injury and heart failure. [23] [24] [25] |
article-27694_26 | Pressure Support -- Clinical Significance | Pressure support provides a set amount of pressure during inspiration to support the spontaneously breathing patient. This mode eases a patient's ability to overcome the resistance of the endotracheal tube and is frequently used during weaning, as it reduces the effort of breathing. Pressure support is considered valuable for the weaning patient population. The critical aspect of ensuring optimal patient outcomes is selecting the appropriate ventilation mode based on the patient's condition and abilities. [21] [18] | Pressure Support -- Clinical Significance. Pressure support provides a set amount of pressure during inspiration to support the spontaneously breathing patient. This mode eases a patient's ability to overcome the resistance of the endotracheal tube and is frequently used during weaning, as it reduces the effort of breathing. Pressure support is considered valuable for the weaning patient population. The critical aspect of ensuring optimal patient outcomes is selecting the appropriate ventilation mode based on the patient's condition and abilities. [21] [18] |
article-27694_27 | Pressure Support -- Other Issues | When a patient requires ventilator weaning in pressure support mode, activating the backup mode on the ventilator is recommended. This mode will be triggered if the patient encounters difficulty breathing or exhibits shallow breaths. | Pressure Support -- Other Issues. When a patient requires ventilator weaning in pressure support mode, activating the backup mode on the ventilator is recommended. This mode will be triggered if the patient encounters difficulty breathing or exhibits shallow breaths. |
article-27694_28 | Pressure Support -- Enhancing Healthcare Team Outcomes | PSV is recognized as a crucial weaning strategy, distinguishing itself from other modes, such as intermittent mandatory ventilation (IMV). Studies have shown that PSV results in a decreased respiratory rate, increased tidal volume, reduced respiratory muscle activity, and decreased oxygen consumption compared to IMV ventilation modes. Therefore, an interprofessional healthcare team approach to care involving clinicians, nursing staff, and respiratory therapists is essential for effectively implementing and monitoring PSV, ultimately contributing to improved patient outcomes. | Pressure Support -- Enhancing Healthcare Team Outcomes. PSV is recognized as a crucial weaning strategy, distinguishing itself from other modes, such as intermittent mandatory ventilation (IMV). Studies have shown that PSV results in a decreased respiratory rate, increased tidal volume, reduced respiratory muscle activity, and decreased oxygen consumption compared to IMV ventilation modes. Therefore, an interprofessional healthcare team approach to care involving clinicians, nursing staff, and respiratory therapists is essential for effectively implementing and monitoring PSV, ultimately contributing to improved patient outcomes. |
article-27694_29 | Pressure Support -- Nursing, Allied Health, and Interprofessional Team Interventions | Ventilator weaning with PSV necessitates a collaborative, multidisciplinary effort involving close cooperation and coordination among the nurse, respiratory therapist, and the healthcare team. Typically, these patients are initiated on PSV, and their sedation is paused. | Pressure Support -- Nursing, Allied Health, and Interprofessional Team Interventions. Ventilator weaning with PSV necessitates a collaborative, multidisciplinary effort involving close cooperation and coordination among the nurse, respiratory therapist, and the healthcare team. Typically, these patients are initiated on PSV, and their sedation is paused. |
article-27694_30 | Pressure Support -- Nursing, Allied Health, and Interprofessional Team Interventions | To avoid complications and self-extubations, the healthcare team should be readily available, and the patient must be closely monitored. Incorporating daily spontaneous breathing trials and sedation vacations, which are part of the ABCDEF bundle, into the best practices of all ICUs, can enhance patient-centered outcomes, including reducing ventilator days and mitigating delirium in the ICU. | Pressure Support -- Nursing, Allied Health, and Interprofessional Team Interventions. To avoid complications and self-extubations, the healthcare team should be readily available, and the patient must be closely monitored. Incorporating daily spontaneous breathing trials and sedation vacations, which are part of the ABCDEF bundle, into the best practices of all ICUs, can enhance patient-centered outcomes, including reducing ventilator days and mitigating delirium in the ICU. |
article-27694_31 | Pressure Support -- Nursing, Allied Health, and Interprofessional Team Monitoring | During the weaning trial on PSV, it is crucial to closely monitor the patient for any signs of respiratory compromise. Respiratory therapists, nurses, and other healthcare team members should collaborate to vigilantly observe the patient throughout the weaning process. | Pressure Support -- Nursing, Allied Health, and Interprofessional Team Monitoring. During the weaning trial on PSV, it is crucial to closely monitor the patient for any signs of respiratory compromise. Respiratory therapists, nurses, and other healthcare team members should collaborate to vigilantly observe the patient throughout the weaning process. |
article-27694_32 | Pressure Support -- Review Questions | Access free multiple choice questions on this topic. Comment on this article. | Pressure Support -- Review Questions. Access free multiple choice questions on this topic. Comment on this article. |
article-38210_0 | Anatomy, Arteries -- Introduction | Arteries make up a major part of the circulatory system, with the veins and heart being the other main components. Arteries make up tubelike structures responsible for transporting fluid (i.e., blood for the circulatory system and lymph for the lymphatic system) to and from every organ in the body. Mainly, arteries manage the transportation of oxygen, nutrients, and hormones through our bodies. Arteries can dispense fresh oxygen to the body after it gets loaded onto the Fe 2+ found in the center of hemoglobin. The oxygen binds to hemoglobin and is carried by the arteries to areas that lack oxygen. Through a shift in affinity for the oxygen, it is then unloaded to specific areas through high surface areas knowns as capillaries. [1] Far from being a changeless structure, arteries adapt through signals received from the central nervous system, as they also react to an outer stimulus like pressure, temperature, and substances. Vascular nerves are responsible for innervating the arteries allowing them to change to their stimuli. As catecholamines get released into the blood, the nerves send signals to the arteries to either constrict or dilate, leading to changes in pressure. [2] | Anatomy, Arteries -- Introduction. Arteries make up a major part of the circulatory system, with the veins and heart being the other main components. Arteries make up tubelike structures responsible for transporting fluid (i.e., blood for the circulatory system and lymph for the lymphatic system) to and from every organ in the body. Mainly, arteries manage the transportation of oxygen, nutrients, and hormones through our bodies. Arteries can dispense fresh oxygen to the body after it gets loaded onto the Fe 2+ found in the center of hemoglobin. The oxygen binds to hemoglobin and is carried by the arteries to areas that lack oxygen. Through a shift in affinity for the oxygen, it is then unloaded to specific areas through high surface areas knowns as capillaries. [1] Far from being a changeless structure, arteries adapt through signals received from the central nervous system, as they also react to an outer stimulus like pressure, temperature, and substances. Vascular nerves are responsible for innervating the arteries allowing them to change to their stimuli. As catecholamines get released into the blood, the nerves send signals to the arteries to either constrict or dilate, leading to changes in pressure. [2] |
article-38210_1 | Anatomy, Arteries -- Introduction | Arteries are composed of smooth muscle allowing constriction and dilation through the parasympathetic nervous system. [3] Arteries differ from veins in that they most often carry oxygenated blood away from the heart and into the rest of the body system. However, this is not always the case, as the pulmonary artery moves unoxygenated blood from the heart to the lungs to complete the gas exchange in the alveoli. [4] Additionally, arteries play an important role in maintaining proper blood flow to the uterus during pregnancy, allowing proper fetal growth. Arteries play a crucial role in maintaining homeostasis in the body. Additionally, arteries begin to clog with a thicking of plaque known as atherosclerosis. [5] | Anatomy, Arteries -- Introduction. Arteries are composed of smooth muscle allowing constriction and dilation through the parasympathetic nervous system. [3] Arteries differ from veins in that they most often carry oxygenated blood away from the heart and into the rest of the body system. However, this is not always the case, as the pulmonary artery moves unoxygenated blood from the heart to the lungs to complete the gas exchange in the alveoli. [4] Additionally, arteries play an important role in maintaining proper blood flow to the uterus during pregnancy, allowing proper fetal growth. Arteries play a crucial role in maintaining homeostasis in the body. Additionally, arteries begin to clog with a thicking of plaque known as atherosclerosis. [5] |
article-38210_2 | Anatomy, Arteries -- Introduction | As individuals age, health issues begin presenting themselves in the form of stiffening or thickening of the arteries. This issue may develop due to a variety of issues ranging from advanced age, poor diet, sedentary lifestyle, and/or genetic factors such as hypercholestreriamiaAs problems arise in the structure of the arteries; it begins leading to more strain on the heart, which develops congestive heart failure and which is often fatal. More commonly, arteries continue to develop plaque which eventually leads to an obstruction of blood flow to vital organs, including the heart. Coronary arteries are crucial to providing the heart with its own blood supply; however, these arteries, such as the rest, are prone to atherosclerosis in untreated high-risk individuals. Depending on where the obstruction occurs in the coronary arteries, blood flow to a particular section or sometimes the entire heart is arrested. Ischemia to cardiac muscles may be seen as ST elevations on EKG monitoring strips as well as a rise in troponin, a significant marker of cardiac injury. If the ischemia persists, the individual may experience myocardial infection, otherwise known as a heart attack. The arteries are vital to maintaining a healthy cardiovascular system, thus, a healthy lifestyle. | Anatomy, Arteries -- Introduction. As individuals age, health issues begin presenting themselves in the form of stiffening or thickening of the arteries. This issue may develop due to a variety of issues ranging from advanced age, poor diet, sedentary lifestyle, and/or genetic factors such as hypercholestreriamiaAs problems arise in the structure of the arteries; it begins leading to more strain on the heart, which develops congestive heart failure and which is often fatal. More commonly, arteries continue to develop plaque which eventually leads to an obstruction of blood flow to vital organs, including the heart. Coronary arteries are crucial to providing the heart with its own blood supply; however, these arteries, such as the rest, are prone to atherosclerosis in untreated high-risk individuals. Depending on where the obstruction occurs in the coronary arteries, blood flow to a particular section or sometimes the entire heart is arrested. Ischemia to cardiac muscles may be seen as ST elevations on EKG monitoring strips as well as a rise in troponin, a significant marker of cardiac injury. If the ischemia persists, the individual may experience myocardial infection, otherwise known as a heart attack. The arteries are vital to maintaining a healthy cardiovascular system, thus, a healthy lifestyle. |
article-38210_3 | Anatomy, Arteries -- Structure and Function | The arteries throughout the body are composed of three different layers (see Image. Artery Layers). The first innermost layer of the artery is known as the intima, which is made up of a smooth muscle layer that contains one layer of endothelial cells, and the rest is smooth muscle and elastin. The tunica intima creates a tube for the oxygen-rich blood to move through to reach the appropriate perfusion site. See Image. Structure of an Artery Wall. In this way, there is no leakage from the artery, and the nutrient-rich blood can move to the appropriate area before it unloads its oxygen and other nutrients. The second layer is known as the media or the middle layer. This media layer is made up of more smooth muscle that can dilate or constrict, which adjusts the pressures felt on the arterial walls during systolic pumping. As the muscle contracts, the walls will feel more pressure from the left ventricle, and similarly, as the vessels dilate, the pressure observed will drop. [6] The last layer is the outermost, known as the adventitia. | Anatomy, Arteries -- Structure and Function. The arteries throughout the body are composed of three different layers (see Image. Artery Layers). The first innermost layer of the artery is known as the intima, which is made up of a smooth muscle layer that contains one layer of endothelial cells, and the rest is smooth muscle and elastin. The tunica intima creates a tube for the oxygen-rich blood to move through to reach the appropriate perfusion site. See Image. Structure of an Artery Wall. In this way, there is no leakage from the artery, and the nutrient-rich blood can move to the appropriate area before it unloads its oxygen and other nutrients. The second layer is known as the media or the middle layer. This media layer is made up of more smooth muscle that can dilate or constrict, which adjusts the pressures felt on the arterial walls during systolic pumping. As the muscle contracts, the walls will feel more pressure from the left ventricle, and similarly, as the vessels dilate, the pressure observed will drop. [6] The last layer is the outermost, known as the adventitia. |
article-38210_4 | Anatomy, Arteries -- Structure and Function | The adventitia is crucial for connecting the arteries to other tissues in the body, including the vascular nerves, which control the smooth muscles in the arteries. In this way, the arteries do not move freely throughout the body but instead are held in place to ensure a consistent and effective cardiovascular system. Usually, the arteries are under the most pressure as they receive blood from the left ventricle, the most powerful section of the heart. However, the pulmonary artery is different for two reasons. Not only does it move unoxygenated blood from the heart to the lungs, but it also handles much less pressure, as the right ventricle has less force than the left. The pulmonary artery leads blood to the lungs while the rest of the arteries move blood to specific areas of the body. The blood from the left ventricle gets pumped through the largest artery, the aorta. The aorta then split into four sections: the ascending aorta, the aortic arch curves over the heart, the descending thoracic aorta, and the abdominal aorta. The ascending aorta moves up from the heart and further divides in the carotid artery, which supplies the brain with blood. [7] | Anatomy, Arteries -- Structure and Function. The adventitia is crucial for connecting the arteries to other tissues in the body, including the vascular nerves, which control the smooth muscles in the arteries. In this way, the arteries do not move freely throughout the body but instead are held in place to ensure a consistent and effective cardiovascular system. Usually, the arteries are under the most pressure as they receive blood from the left ventricle, the most powerful section of the heart. However, the pulmonary artery is different for two reasons. Not only does it move unoxygenated blood from the heart to the lungs, but it also handles much less pressure, as the right ventricle has less force than the left. The pulmonary artery leads blood to the lungs while the rest of the arteries move blood to specific areas of the body. The blood from the left ventricle gets pumped through the largest artery, the aorta. The aorta then split into four sections: the ascending aorta, the aortic arch curves over the heart, the descending thoracic aorta, and the abdominal aorta. The ascending aorta moves up from the heart and further divides in the carotid artery, which supplies the brain with blood. [7] |
article-38210_5 | Anatomy, Arteries -- Structure and Function | The aortic arch is similar to the ascending aorta and carries blood up to the back and neck. The descending aorta brings blood from the heart to smaller vessels in the chest or ribs. Finally, the abdominal aorta carries blood to the iliac arteries, which provide circulation for many organs in the abdominal region. [8] | Anatomy, Arteries -- Structure and Function. The aortic arch is similar to the ascending aorta and carries blood up to the back and neck. The descending aorta brings blood from the heart to smaller vessels in the chest or ribs. Finally, the abdominal aorta carries blood to the iliac arteries, which provide circulation for many organs in the abdominal region. [8] |
article-38210_6 | Anatomy, Arteries -- Embryology | During development, the arteries constantly change to maintain balance in changing environments. The heart and arteries develop from the mesoderm germ layer as it is composed of smooth muscle. After the mesoderm begins to differentiate into sections of the circulatory system due to specific growth factor signaling, the arteries start to form, and circulation powered by the heart initiates. At the beginning of development, the arteries form from the pharyngeal arches. Each arch changes into a specific arterial section during the 9-month pregnancy. | Anatomy, Arteries -- Embryology. During development, the arteries constantly change to maintain balance in changing environments. The heart and arteries develop from the mesoderm germ layer as it is composed of smooth muscle. After the mesoderm begins to differentiate into sections of the circulatory system due to specific growth factor signaling, the arteries start to form, and circulation powered by the heart initiates. At the beginning of development, the arteries form from the pharyngeal arches. Each arch changes into a specific arterial section during the 9-month pregnancy. |
article-38210_7 | Anatomy, Arteries -- Embryology | During pregnancy, the fetus has a sharded circulatory system with the mother, making the movement of blood unique. The uterine arteries carry blood from the mother to the placenta, where it can perfuse and travel to the fetus to supply it with oxygen. Fetal hearts also have a unique blood flow as blood does not become oxygenated in its lungs but instead by the mother. A fetus has a unique connection between the aorta and the pulmonary called ductus arteriosus. [9] This connection allows blood to flow past the lungs of the fetus as they are not in use while the fetus is in the amniotic sac. | Anatomy, Arteries -- Embryology. During pregnancy, the fetus has a sharded circulatory system with the mother, making the movement of blood unique. The uterine arteries carry blood from the mother to the placenta, where it can perfuse and travel to the fetus to supply it with oxygen. Fetal hearts also have a unique blood flow as blood does not become oxygenated in its lungs but instead by the mother. A fetus has a unique connection between the aorta and the pulmonary called ductus arteriosus. [9] This connection allows blood to flow past the lungs of the fetus as they are not in use while the fetus is in the amniotic sac. |
article-38210_8 | Anatomy, Arteries -- Muscles | In all of these examples, arteries are comprised of smooth muscle. They are nonstriated muscles encompassing the vessels to provide support and integrity to the entire artery. This smooth muscle reacts to different signals and innervations to constrict or dilate to maintain consistent blood pressure, such as epinephrine and angiotensin II. The sympathetic nervous system can use high levels of epinephrine, which affects alpha-adrenergic receptors to cause the arteries to constrict. This increase in pressure can aid in perfusion during both trauma and hormonal imbalance. [10] | Anatomy, Arteries -- Muscles. In all of these examples, arteries are comprised of smooth muscle. They are nonstriated muscles encompassing the vessels to provide support and integrity to the entire artery. This smooth muscle reacts to different signals and innervations to constrict or dilate to maintain consistent blood pressure, such as epinephrine and angiotensin II. The sympathetic nervous system can use high levels of epinephrine, which affects alpha-adrenergic receptors to cause the arteries to constrict. This increase in pressure can aid in perfusion during both trauma and hormonal imbalance. [10] |
article-38210_9 | Anatomy, Arteries -- Muscles | Additionally, the kidney can indirectly affect blood pressure through its release of renin. Renin allows for the creation of angiotensin II, a powerful vasoconstrictor. [11] Angiotensin II interacts directly with the smooth muscles in the arteries, causing constriction when blood pressure drops below normal. Additionally, as blood pressure drops due to bleeding or peripheral arterial dilation, as in the setting of shock, the arteries cooperate with the renin-angiotensin-aldosterone system to compensate for the decrease. | Anatomy, Arteries -- Muscles. Additionally, the kidney can indirectly affect blood pressure through its release of renin. Renin allows for the creation of angiotensin II, a powerful vasoconstrictor. [11] Angiotensin II interacts directly with the smooth muscles in the arteries, causing constriction when blood pressure drops below normal. Additionally, as blood pressure drops due to bleeding or peripheral arterial dilation, as in the setting of shock, the arteries cooperate with the renin-angiotensin-aldosterone system to compensate for the decrease. |
article-38210_10 | Anatomy, Arteries -- Muscles | As arteries age, they harden and become less compliant, leading to an imbalance in this system that can lead to secondary hypertension due to a low glomerular filtration rate in the kidneys. Therefore through the endocrine system, different hormones are released into the blood, which is then able to signal the vascular nerves to change to maintain homeostasis. | Anatomy, Arteries -- Muscles. As arteries age, they harden and become less compliant, leading to an imbalance in this system that can lead to secondary hypertension due to a low glomerular filtration rate in the kidneys. Therefore through the endocrine system, different hormones are released into the blood, which is then able to signal the vascular nerves to change to maintain homeostasis. |
article-38210_11 | Anatomy, Arteries -- Surgical Considerations | The different surgical considerations with regard to arterial anatomy are: Aneurysms - May need surgical ligation, stenting, or clipping based on the location Arteriovenous fistula - May need separation of the vessels Ligation of an arterial bleeder - May need a trans-fixation suture for major arteries Thrombo-embolism - May need open/interventional radiology-assisted evacuation | Anatomy, Arteries -- Surgical Considerations. The different surgical considerations with regard to arterial anatomy are: Aneurysms - May need surgical ligation, stenting, or clipping based on the location Arteriovenous fistula - May need separation of the vessels Ligation of an arterial bleeder - May need a trans-fixation suture for major arteries Thrombo-embolism - May need open/interventional radiology-assisted evacuation |
article-38210_12 | Anatomy, Arteries -- Clinical Significance | There are many more ways that arteries aid in maintaining balance, including some vasodilators such as histamine or serotonin. This, however, can become dangerous if balance is not maintained. An angiogram, or insertion of a tube and dye into the artery, can be used to monitor the blood flow to identify bleeds or blockages. However, environmental factors also play a role in the structure of arteries. For example, during anaphylaxis shock, massive amounts of histamine are released into the body, causing the arteries to dilate to an unsafe amount. This creates a lack of pressure for the perfusion of nutrient-rich blood. In an attempt to make up for this loss, the body begins entering a state of compensated shock by the heart rate. This does not work forever, and without dilation, the patient will soon go into a state of shock. In addition to having to be balanced, many medical issues may arise that would further complicate the situation. | Anatomy, Arteries -- Clinical Significance. There are many more ways that arteries aid in maintaining balance, including some vasodilators such as histamine or serotonin. This, however, can become dangerous if balance is not maintained. An angiogram, or insertion of a tube and dye into the artery, can be used to monitor the blood flow to identify bleeds or blockages. However, environmental factors also play a role in the structure of arteries. For example, during anaphylaxis shock, massive amounts of histamine are released into the body, causing the arteries to dilate to an unsafe amount. This creates a lack of pressure for the perfusion of nutrient-rich blood. In an attempt to make up for this loss, the body begins entering a state of compensated shock by the heart rate. This does not work forever, and without dilation, the patient will soon go into a state of shock. In addition to having to be balanced, many medical issues may arise that would further complicate the situation. |
article-38210_13 | Anatomy, Arteries -- Clinical Significance | One of the most common medical problems concerning arteries is atherosclerosis; the arteries build up with plaque until it affects normal cardiovascular function. This compilation of plaque can form anywhere, meaning a blockage can develop in any area. A myocardial infarction will occur if the blood supply gets cut off from the heart. [12] Similarly, if there is a blockage of blood flow supplying the brain, this is known as a stroke. A lack of blood supply to any area of the body can cause permanent severe damage or even death. Ischemia to any vital organ is severe and may present in a large variety of presentations. For example, if blood supply is cut off from the retina, then one may develop amaurosis fugax or blindness. [13] Trans-fats and bad cholesterol have been shown to affect arteries negatively, leading to atherosclerosis. Therefore it is crucial to maintain a healthy lifestyle through diet and exercise. Individuals who maintain a healthy lifestyle and retain high LDL levels should also be screened for genetic components such as familial hypercholesterolemia. | Anatomy, Arteries -- Clinical Significance. One of the most common medical problems concerning arteries is atherosclerosis; the arteries build up with plaque until it affects normal cardiovascular function. This compilation of plaque can form anywhere, meaning a blockage can develop in any area. A myocardial infarction will occur if the blood supply gets cut off from the heart. [12] Similarly, if there is a blockage of blood flow supplying the brain, this is known as a stroke. A lack of blood supply to any area of the body can cause permanent severe damage or even death. Ischemia to any vital organ is severe and may present in a large variety of presentations. For example, if blood supply is cut off from the retina, then one may develop amaurosis fugax or blindness. [13] Trans-fats and bad cholesterol have been shown to affect arteries negatively, leading to atherosclerosis. Therefore it is crucial to maintain a healthy lifestyle through diet and exercise. Individuals who maintain a healthy lifestyle and retain high LDL levels should also be screened for genetic components such as familial hypercholesterolemia. |
article-38210_14 | Anatomy, Arteries -- Clinical Significance | Individuals with a history of stroke or transient ischemic attack (TIA) should be evaluated with carotid ultrasound to assess the level of stenosis. Vascular surgery may be performed to open the arterial lumen further, depending on the level of stenosis or obstruction in these major vessels. This process is often achieved through ballooning and stenting of the artery through subclavian artery access. This procedure is minimally invasive and referred to as TCAR. If TCAR is unsuccessful, an endarterectomy may be performed to open the artery and remove any atherosclerotic plaque buildup directly. The cardiovascular system is essential for keeping all other systems in the body. Arteries, in particular, are vital in supplying nutrients, including oxygen, to the rest of the body. It is crucial to recognize the part that arteries play in the cardiovascular system to prevent medical obstacles in the future. | Anatomy, Arteries -- Clinical Significance. Individuals with a history of stroke or transient ischemic attack (TIA) should be evaluated with carotid ultrasound to assess the level of stenosis. Vascular surgery may be performed to open the arterial lumen further, depending on the level of stenosis or obstruction in these major vessels. This process is often achieved through ballooning and stenting of the artery through subclavian artery access. This procedure is minimally invasive and referred to as TCAR. If TCAR is unsuccessful, an endarterectomy may be performed to open the artery and remove any atherosclerotic plaque buildup directly. The cardiovascular system is essential for keeping all other systems in the body. Arteries, in particular, are vital in supplying nutrients, including oxygen, to the rest of the body. It is crucial to recognize the part that arteries play in the cardiovascular system to prevent medical obstacles in the future. |
article-38210_15 | Anatomy, Arteries -- Review Questions | Access free multiple choice questions on this topic. Comment on this article. | Anatomy, Arteries -- Review Questions. Access free multiple choice questions on this topic. Comment on this article. |
article-67476_0 | Physiology, Homeostasis -- Introduction | Homeostasis is a term that was first coined by physiologist Walter Cannon in 1926, clarifying the 'milieu intérieur' that fellow physiologist Claude Bernard had spoken of in 1865. [1] 'Homeo,' Latinized from the Greek word 'homio,' means 'similar to,' and when combined with the Greek word 'stasis,' meaning 'standing still' gives us the term that is a cornerstone of physiology. Carl Richter proposed that behavioral responses were also responsible for maintaining homeostasis in addition to the previously proposed internal control system, while James Hardy gave us the concept of a setpoint or desired physiological range of values that homeostasis accomplishes. [2] | Physiology, Homeostasis -- Introduction. Homeostasis is a term that was first coined by physiologist Walter Cannon in 1926, clarifying the 'milieu intérieur' that fellow physiologist Claude Bernard had spoken of in 1865. [1] 'Homeo,' Latinized from the Greek word 'homio,' means 'similar to,' and when combined with the Greek word 'stasis,' meaning 'standing still' gives us the term that is a cornerstone of physiology. Carl Richter proposed that behavioral responses were also responsible for maintaining homeostasis in addition to the previously proposed internal control system, while James Hardy gave us the concept of a setpoint or desired physiological range of values that homeostasis accomplishes. [2] |
article-67476_1 | Physiology, Homeostasis -- Introduction | The body's many functions, beginning at the cellular level, operate as to not deviate from a narrow range of internal balance, a state known as dynamic equilibrium, despite changes in the external environment. Those changes in the external environment alter the composition of the extracellular fluid surrounding the individual cells of the body, but a narrow range must be maintained to stave off the death of cells, tissues, and organs. | Physiology, Homeostasis -- Introduction. The body's many functions, beginning at the cellular level, operate as to not deviate from a narrow range of internal balance, a state known as dynamic equilibrium, despite changes in the external environment. Those changes in the external environment alter the composition of the extracellular fluid surrounding the individual cells of the body, but a narrow range must be maintained to stave off the death of cells, tissues, and organs. |
article-67476_2 | Physiology, Homeostasis -- Cellular Level | On the cellular level, homeostasis is observable in the biochemical reactions that take place. Regulation of pH, temperature, oxygen, ion concentrations, and blood glucose concentration is necessary for enzymes to function optimally in the environment of the cell, and the formation of waste products must be kept in control as not to disrupt the internal environment of the cells as well. The cell will remain alive as long as the internal environment is favorable and can be a functioning part of the tissue to which it belongs. [3] | Physiology, Homeostasis -- Cellular Level. On the cellular level, homeostasis is observable in the biochemical reactions that take place. Regulation of pH, temperature, oxygen, ion concentrations, and blood glucose concentration is necessary for enzymes to function optimally in the environment of the cell, and the formation of waste products must be kept in control as not to disrupt the internal environment of the cells as well. The cell will remain alive as long as the internal environment is favorable and can be a functioning part of the tissue to which it belongs. [3] |
article-67476_3 | Physiology, Homeostasis -- Cellular Level | Cells respond to changes in volume by activating the metabolic transport of molecules necessary to return to back to normal volume. [4] In both, the cases of hyperosmolar or hypoosmolar external cellular states, the transfer of molecules must result in volume regulation as not to disturb the contents of the cell from their maximum function. All tissues of the body compose organs that comprise organ systems, which do not operate independently and must work together to achieve homeostasis. Each cell benefits from homeostatic control, and contributes to its maintenance as well, providing continuous automaticity to the body. | Physiology, Homeostasis -- Cellular Level. Cells respond to changes in volume by activating the metabolic transport of molecules necessary to return to back to normal volume. [4] In both, the cases of hyperosmolar or hypoosmolar external cellular states, the transfer of molecules must result in volume regulation as not to disturb the contents of the cell from their maximum function. All tissues of the body compose organs that comprise organ systems, which do not operate independently and must work together to achieve homeostasis. Each cell benefits from homeostatic control, and contributes to its maintenance as well, providing continuous automaticity to the body. |
article-67476_4 | Physiology, Homeostasis -- Development | Homeostasis would not be possible without setpoints, feedback, and regulation. The human body is composed of thousands of control systems to detect change caused by disruptors and employ effectors to mediate that change. The setpoint is invaluable in the development of the homeostatic control system and is the value that the system designs the output to be. [5] Homeostatic regulation involves both local control (paracrine or autocrine responses) as well as reflex control (involving the nervous and endocrine systems). | Physiology, Homeostasis -- Development. Homeostasis would not be possible without setpoints, feedback, and regulation. The human body is composed of thousands of control systems to detect change caused by disruptors and employ effectors to mediate that change. The setpoint is invaluable in the development of the homeostatic control system and is the value that the system designs the output to be. [5] Homeostatic regulation involves both local control (paracrine or autocrine responses) as well as reflex control (involving the nervous and endocrine systems). |
article-67476_5 | Physiology, Homeostasis -- Development | Although homeostasis is central to understand internal regulation, allostasis, or maintaining stability through change, is worthy of mention, as it is also necessary for organisms to adapt to their environments. [6] Allostasis considers the normal daily variations that exist in the internal system. As such, a difference between homeostasis and allostasis is that, although the goal of homeostasis is to reduce variability and maintain consistency, allostasis favors variability because the internal environment can adapt to various environmental encounters. [7] Although the two concepts may differ, it is important to note the existence of each and their contribution to physiology. | Physiology, Homeostasis -- Development. Although homeostasis is central to understand internal regulation, allostasis, or maintaining stability through change, is worthy of mention, as it is also necessary for organisms to adapt to their environments. [6] Allostasis considers the normal daily variations that exist in the internal system. As such, a difference between homeostasis and allostasis is that, although the goal of homeostasis is to reduce variability and maintain consistency, allostasis favors variability because the internal environment can adapt to various environmental encounters. [7] Although the two concepts may differ, it is important to note the existence of each and their contribution to physiology. |
article-67476_6 | Physiology, Homeostasis -- Organ Systems Involved | Homeostasis is involved in every organ system of the body. In a similar vein, no one organ system of the body acts alone; regulation of body temperature cannot occur without the cooperation of the integumentary system, nervous system, musculoskeletal system, and cardiovascular system at a minimum. Chemosensors in the carotid bodies and aortic body measure arterial PCO2 and PO2, send the information to the brainstem (control center), to tell the effectors (the diaphragm and respiratory muscles) to alter breathing rate and tidal volume to return to balance. Altered reabsorption and secretion of inorganic ions are the result of chemosensors in the adrenal cortex (for potassium concentration), parathyroid gland (for calcium concentration), and kidney and carotid and aortic bodies (for sodium concentration) which help to bring these regulated variables back to the normal range. | Physiology, Homeostasis -- Organ Systems Involved. Homeostasis is involved in every organ system of the body. In a similar vein, no one organ system of the body acts alone; regulation of body temperature cannot occur without the cooperation of the integumentary system, nervous system, musculoskeletal system, and cardiovascular system at a minimum. Chemosensors in the carotid bodies and aortic body measure arterial PCO2 and PO2, send the information to the brainstem (control center), to tell the effectors (the diaphragm and respiratory muscles) to alter breathing rate and tidal volume to return to balance. Altered reabsorption and secretion of inorganic ions are the result of chemosensors in the adrenal cortex (for potassium concentration), parathyroid gland (for calcium concentration), and kidney and carotid and aortic bodies (for sodium concentration) which help to bring these regulated variables back to the normal range. |
article-67476_7 | Physiology, Homeostasis -- Function | In short, the purpose of homeostasis is to maintain the established internal environment without being overcome by external stimuli that exist to disrupt the balance. | Physiology, Homeostasis -- Function. In short, the purpose of homeostasis is to maintain the established internal environment without being overcome by external stimuli that exist to disrupt the balance. |
article-67476_8 | Physiology, Homeostasis -- Mechanism | A proposed mechanism for homeostasis is represented by a regulatory system in which five critical components must work together in a reflex loop: the sensor, setpoint, error detector, controller, and effector. [5] A regulated (sensed) variable has a sensor within the system to measure the change in its value, an example of which is blood glucose concentration. On the other hand, a controlled (nonregulated) variable whose value becomes altered to maintain the regulated variable in the narrow range, an example of which would be the roles of gluconeogenesis, glycolysis, and glycogenolysis in blood glucose concentration. [2] | Physiology, Homeostasis -- Mechanism. A proposed mechanism for homeostasis is represented by a regulatory system in which five critical components must work together in a reflex loop: the sensor, setpoint, error detector, controller, and effector. [5] A regulated (sensed) variable has a sensor within the system to measure the change in its value, an example of which is blood glucose concentration. On the other hand, a controlled (nonregulated) variable whose value becomes altered to maintain the regulated variable in the narrow range, an example of which would be the roles of gluconeogenesis, glycolysis, and glycogenolysis in blood glucose concentration. [2] |
article-67476_9 | Physiology, Homeostasis -- Mechanism | A controller's role is to interpret an error signal and determine the outputs of the effectors so that homeostasis is once again attainable. Thus, in the body, controllers are usually the endocrine cells and sensory neurons in the autonomic nervous system, medulla, and hypothalamus. The effectors produce the response that forces the variable back to the normal range. Receptors monitor a change in the environment, a stimulus, which is transmitted to the integration center (for example, the brain in the case of the central nervous system, or a gland in the endocrine system). If the determination is that the stimulus differs from the setpoint, it generates a response and sent to the effector organ. A system that utilizes these components is known as a negative feedback system, although the opposite is not true: negative feedback does not mean the system is homeostatic in function. [5] | Physiology, Homeostasis -- Mechanism. A controller's role is to interpret an error signal and determine the outputs of the effectors so that homeostasis is once again attainable. Thus, in the body, controllers are usually the endocrine cells and sensory neurons in the autonomic nervous system, medulla, and hypothalamus. The effectors produce the response that forces the variable back to the normal range. Receptors monitor a change in the environment, a stimulus, which is transmitted to the integration center (for example, the brain in the case of the central nervous system, or a gland in the endocrine system). If the determination is that the stimulus differs from the setpoint, it generates a response and sent to the effector organ. A system that utilizes these components is known as a negative feedback system, although the opposite is not true: negative feedback does not mean the system is homeostatic in function. [5] |
article-67476_10 | Physiology, Homeostasis -- Mechanism | Negative feedback refers to a response that is opposite to the stress: the compensatory action will increase values if they become too low or decrease if they become too high. Anticipatory (feedforward) controls exist to minimize the disturbance of a predicted change in the environment when anticipating a change. [8] In this type of feedback, controls do not activate when there is a perturbance to the system, but rather before it occurs, as to prepare for the effects that disturbance would have. Lastly, although not as frequently occurring as negative feedback loops, positive feedback, in which the stimulus is reinforced rather than decreased, is necessary in some cases as well. One of the most well-known examples of positive feedback occurs during labor when the release of oxytocin stimulates uterine contractions forcing the baby's head to push against the cervix, which stimulates the release of more oxytocin which cycles until delivery is complete. | Physiology, Homeostasis -- Mechanism. Negative feedback refers to a response that is opposite to the stress: the compensatory action will increase values if they become too low or decrease if they become too high. Anticipatory (feedforward) controls exist to minimize the disturbance of a predicted change in the environment when anticipating a change. [8] In this type of feedback, controls do not activate when there is a perturbance to the system, but rather before it occurs, as to prepare for the effects that disturbance would have. Lastly, although not as frequently occurring as negative feedback loops, positive feedback, in which the stimulus is reinforced rather than decreased, is necessary in some cases as well. One of the most well-known examples of positive feedback occurs during labor when the release of oxytocin stimulates uterine contractions forcing the baby's head to push against the cervix, which stimulates the release of more oxytocin which cycles until delivery is complete. |
article-67476_11 | Physiology, Homeostasis -- Related Testing | A patient's vital signs (blood pressure, core body temperature, heart rate, respiratory rate, and oxygen saturation) are the first measurement indicating if there is a homeostatic imbalance. A basic metabolic panel is a quick blood test to show electrolyte disturbances, if present, to guide diagnosis and treatment. Measurement of the inorganic ions, kidney function (BUN/Creatinine ratio), and glucose enable us to fix those abnormalities as well as the underlying cause. | Physiology, Homeostasis -- Related Testing. A patient's vital signs (blood pressure, core body temperature, heart rate, respiratory rate, and oxygen saturation) are the first measurement indicating if there is a homeostatic imbalance. A basic metabolic panel is a quick blood test to show electrolyte disturbances, if present, to guide diagnosis and treatment. Measurement of the inorganic ions, kidney function (BUN/Creatinine ratio), and glucose enable us to fix those abnormalities as well as the underlying cause. |
article-67476_12 | Physiology, Homeostasis -- Pathophysiology | Homeostasis underlies many, if not all, disease processes. Diseases such as diabetes, hypertension, and atherosclerosis, involve both the disturbance of homeostasis, as well as the presence of inflammation. [2] The loss of receptor sensitivity with age increases the risk of illness as an unstable internal environment is allowed to exist. [9] Older individuals are more susceptible to temperature dysregulation and have impaired thirst mechanisms, which contribute to the elevated risk of dehydration seen in this population. Acid-base imbalances underlie acid-base disorders and electrolyte abnormalities that exist from a plethora of medical conditions or medication side effects. Additionally, water balance in terms of fluid maintenance is crucial as not to overload the patient, or underhydrate the patient's cells. Overload would be detrimental to a person with underlying cardiovascular or respiratory conditions. Thus, an individualized approach is necessary to correct a patient's fluid balance, especially in surgical patients. [10] | Physiology, Homeostasis -- Pathophysiology. Homeostasis underlies many, if not all, disease processes. Diseases such as diabetes, hypertension, and atherosclerosis, involve both the disturbance of homeostasis, as well as the presence of inflammation. [2] The loss of receptor sensitivity with age increases the risk of illness as an unstable internal environment is allowed to exist. [9] Older individuals are more susceptible to temperature dysregulation and have impaired thirst mechanisms, which contribute to the elevated risk of dehydration seen in this population. Acid-base imbalances underlie acid-base disorders and electrolyte abnormalities that exist from a plethora of medical conditions or medication side effects. Additionally, water balance in terms of fluid maintenance is crucial as not to overload the patient, or underhydrate the patient's cells. Overload would be detrimental to a person with underlying cardiovascular or respiratory conditions. Thus, an individualized approach is necessary to correct a patient's fluid balance, especially in surgical patients. [10] |
article-67476_13 | Physiology, Homeostasis -- Pathophysiology | The setpoint must confine itself to a strict range in certain body functions, but it is not necessarily static in others. For example, deviation of arterial blood gas values from the accepted range would be detrimental to a living system. However, when the body is deprived of food, a 'new normal' must be adjusted to function with less energy and a slower metabolism rate. [9] Without this adaptation, the body's cells would be deprived of the needed nutrients and would die quickly, which is not the case, as a living organism can survive on less intake as long as the energy can be maintained. Disruption in thermoregulation could lead to hypothermia if the body's core temperature falls below the threshold for optimal cellular functioning, or hyperthermia if the body's core temperature exceeds the highest. Fever is another example of how the setpoint can increase without necessarily killing the individual. [2] An increase in core body temperature is necessary to fight off an invader, but in the case of hyperthermia, the adaptive function of temperature has failed, and the setpoint is unable to return to normal. | Physiology, Homeostasis -- Pathophysiology. The setpoint must confine itself to a strict range in certain body functions, but it is not necessarily static in others. For example, deviation of arterial blood gas values from the accepted range would be detrimental to a living system. However, when the body is deprived of food, a 'new normal' must be adjusted to function with less energy and a slower metabolism rate. [9] Without this adaptation, the body's cells would be deprived of the needed nutrients and would die quickly, which is not the case, as a living organism can survive on less intake as long as the energy can be maintained. Disruption in thermoregulation could lead to hypothermia if the body's core temperature falls below the threshold for optimal cellular functioning, or hyperthermia if the body's core temperature exceeds the highest. Fever is another example of how the setpoint can increase without necessarily killing the individual. [2] An increase in core body temperature is necessary to fight off an invader, but in the case of hyperthermia, the adaptive function of temperature has failed, and the setpoint is unable to return to normal. |
article-67476_14 | Physiology, Homeostasis -- Clinical Significance | All in all, every medical condition can be traced back to failure at some point in the homeostatic control system, whether it be in the inability to detect the initial external change, failure of initiating a feedback loop, failure to enact a response to return to the setpoint, or failure in the setpoint itself. The goal of the health care provider must be to restabilize the internal milieu of the body without causing further harm and to do so promptly to avoid the death of cells from dysregulation, and irreparable failure of organ systems. | Physiology, Homeostasis -- Clinical Significance. All in all, every medical condition can be traced back to failure at some point in the homeostatic control system, whether it be in the inability to detect the initial external change, failure of initiating a feedback loop, failure to enact a response to return to the setpoint, or failure in the setpoint itself. The goal of the health care provider must be to restabilize the internal milieu of the body without causing further harm and to do so promptly to avoid the death of cells from dysregulation, and irreparable failure of organ systems. |
article-67476_15 | Physiology, Homeostasis -- Review Questions | Access free multiple choice questions on this topic. Comment on this article. | Physiology, Homeostasis -- Review Questions. Access free multiple choice questions on this topic. Comment on this article. |
article-22264_0 | Open Angle Glaucoma -- Continuing Education Activity | Open-angle glaucoma (OAG) is a chronic, progressive, and irreversible multifactorial optic neuropathy. Characterized by an open angle of the anterior chamber, optic nerve head changes, and a gradual decline in peripheral vision followed by central visual field loss, OAG remains asymptomatic until advanced stages, emphasizing the critical need for early detection and management. Elevated intraocular pressure is a key risk factor for primary or secondary causes. Participating clinicians review the causes of OAG, pathophysiology, and the latest evidence-based strategies for evaluation and management. | Open Angle Glaucoma -- Continuing Education Activity. Open-angle glaucoma (OAG) is a chronic, progressive, and irreversible multifactorial optic neuropathy. Characterized by an open angle of the anterior chamber, optic nerve head changes, and a gradual decline in peripheral vision followed by central visual field loss, OAG remains asymptomatic until advanced stages, emphasizing the critical need for early detection and management. Elevated intraocular pressure is a key risk factor for primary or secondary causes. Participating clinicians review the causes of OAG, pathophysiology, and the latest evidence-based strategies for evaluation and management. |
article-22264_1 | Open Angle Glaucoma -- Continuing Education Activity | This course evaluates the complexities of OAG, and describes how early detection and management can help prevent irreversible vision loss and preserve patients' quality of life. Participants explore the multifactorial nature of OAG, including its pathophysiology, risk factors, and clinical manifestations. The latest evidence-based strategies for evaluating and managing OAG, focusing on lowering intraocular pressure, are thoroughly discussed. Additionally, the importance of early intervention and regular monitoring to prevent disease progression is emphasized. This course highlights the pivotal role of the interprofessional team in OAG management. Collaborative efforts among ophthalmologists, optometrists, primary care providers, and allied healthcare professionals enhance early detection, facilitate timely referrals, and ensure comprehensive patient care | Open Angle Glaucoma -- Continuing Education Activity. This course evaluates the complexities of OAG, and describes how early detection and management can help prevent irreversible vision loss and preserve patients' quality of life. Participants explore the multifactorial nature of OAG, including its pathophysiology, risk factors, and clinical manifestations. The latest evidence-based strategies for evaluating and managing OAG, focusing on lowering intraocular pressure, are thoroughly discussed. Additionally, the importance of early intervention and regular monitoring to prevent disease progression is emphasized. This course highlights the pivotal role of the interprofessional team in OAG management. Collaborative efforts among ophthalmologists, optometrists, primary care providers, and allied healthcare professionals enhance early detection, facilitate timely referrals, and ensure comprehensive patient care |
article-22264_2 | Open Angle Glaucoma -- Continuing Education Activity | Objectives: Identify risk factors and early signs of open-angle glaucoma during routine patient evaluations. Differentiate between open-angle glaucoma and other ocular conditions that may present with similar symptoms, ensuring accurate diagnosis and appropriate management. Assess disease progression and treatment efficacy regularly through comprehensive ocular examinations and monitoring intraocular pressure levels. Implement care coordination amongst interprofessional teams to advance the treatment of open-angle glaucoma and improve patient outcomes. Access free multiple choice questions on this topic. | Open Angle Glaucoma -- Continuing Education Activity. Objectives: Identify risk factors and early signs of open-angle glaucoma during routine patient evaluations. Differentiate between open-angle glaucoma and other ocular conditions that may present with similar symptoms, ensuring accurate diagnosis and appropriate management. Assess disease progression and treatment efficacy regularly through comprehensive ocular examinations and monitoring intraocular pressure levels. Implement care coordination amongst interprofessional teams to advance the treatment of open-angle glaucoma and improve patient outcomes. Access free multiple choice questions on this topic. |
article-22264_3 | Open Angle Glaucoma -- Introduction | Glaucoma is a collection of diseases where increased intraocular pressure (IOP) adversely impacts the optic nerve and, subsequently, the visual field. [1] However, not all cases of glaucoma are associated with increased IOP. A subset includes similar optic nerve and visual field damage, known as normal pressure glaucoma. [2] The collection of glaucomatous diseases is subdivided into open-angle and closed-angle glaucoma, both of which can have primary or secondary causes and can be of an iatrogenic or non-iatrogenic origin (see Image. Classification of Open-Angle Glaucoma). | Open Angle Glaucoma -- Introduction. Glaucoma is a collection of diseases where increased intraocular pressure (IOP) adversely impacts the optic nerve and, subsequently, the visual field. [1] However, not all cases of glaucoma are associated with increased IOP. A subset includes similar optic nerve and visual field damage, known as normal pressure glaucoma. [2] The collection of glaucomatous diseases is subdivided into open-angle and closed-angle glaucoma, both of which can have primary or secondary causes and can be of an iatrogenic or non-iatrogenic origin (see Image. Classification of Open-Angle Glaucoma). |
article-22264_4 | Open Angle Glaucoma -- Introduction | Open-angle glaucoma (OAG) is a chronic, progressive, and irreversible multifactorial optic neuropathy characterized by an open angle of the anterior chamber, typical optic nerve head changes, retinal nerve fiber layer thinning, and progressive loss of peripheral vision (see Image. Visual Field and Optical Coherence Tomography, OCT). Central visual field loss and blindness can occur in the advanced stages of glaucoma. IOP is an important risk factor and the target for therapy when treating patients. [3] | Open Angle Glaucoma -- Introduction. Open-angle glaucoma (OAG) is a chronic, progressive, and irreversible multifactorial optic neuropathy characterized by an open angle of the anterior chamber, typical optic nerve head changes, retinal nerve fiber layer thinning, and progressive loss of peripheral vision (see Image. Visual Field and Optical Coherence Tomography, OCT). Central visual field loss and blindness can occur in the advanced stages of glaucoma. IOP is an important risk factor and the target for therapy when treating patients. [3] |
article-22264_5 | Open Angle Glaucoma -- Introduction | The disease is usually bilateral, but asymmetry depends on the etiology. Although increased IOP is a significant risk factor in developing glaucoma, IOP levels greater than 21 mm Hg do not necessarily cause glaucoma and optic nerve damage in all patients. [4] Studies have shown asymptomatic individuals with ocular hypertension who maintain normal visual fields and healthy optic nerves. [5] | Open Angle Glaucoma -- Introduction. The disease is usually bilateral, but asymmetry depends on the etiology. Although increased IOP is a significant risk factor in developing glaucoma, IOP levels greater than 21 mm Hg do not necessarily cause glaucoma and optic nerve damage in all patients. [4] Studies have shown asymptomatic individuals with ocular hypertension who maintain normal visual fields and healthy optic nerves. [5] |
article-22264_6 | Open Angle Glaucoma -- Etiology | Understanding the formation and drainage of aqueous humor is necessary to comprehend the etiology of OAG. The ciliary body continuously produces aqueous humor in the posterior chamber and drains it into the eye's anterior chamber. Most aqueous humor drainage occurs through the trabecular meshwork, and a minority of aqueous outflow is drained through the uveoscleral pathway. | Open Angle Glaucoma -- Etiology. Understanding the formation and drainage of aqueous humor is necessary to comprehend the etiology of OAG. The ciliary body continuously produces aqueous humor in the posterior chamber and drains it into the eye's anterior chamber. Most aqueous humor drainage occurs through the trabecular meshwork, and a minority of aqueous outflow is drained through the uveoscleral pathway. |
article-22264_7 | Open Angle Glaucoma -- Etiology | Primary open-angle glaucoma (POAG) is the most common type, characterized by increased resistance to drainage in the trabecular meshwork. However, the drainage angle between the cornea and iris remains open. [6] Due to this blockage, the pressure in the eye gradually increases, resulting in optic nerve damage and progressive visual loss. Secondary OAG can have multiple etiologies but is far less common than POAG. | Open Angle Glaucoma -- Etiology. Primary open-angle glaucoma (POAG) is the most common type, characterized by increased resistance to drainage in the trabecular meshwork. However, the drainage angle between the cornea and iris remains open. [6] Due to this blockage, the pressure in the eye gradually increases, resulting in optic nerve damage and progressive visual loss. Secondary OAG can have multiple etiologies but is far less common than POAG. |
article-22264_8 | Open Angle Glaucoma -- Etiology -- Genetic | Chromosome 1q24.3, MYOC gene: Myocilin is a cytoskeletal protein product of the MYOC gene, implicated in cases of hereditary juvenile OAG and adult OAG. Myocilin is a cytoskeletal protein expressed in the trabecular meshwork and is also known as trabecular meshwork glucocorticoid-inducible response protein. [7] | Open Angle Glaucoma -- Etiology -- Genetic. Chromosome 1q24.3, MYOC gene: Myocilin is a cytoskeletal protein product of the MYOC gene, implicated in cases of hereditary juvenile OAG and adult OAG. Myocilin is a cytoskeletal protein expressed in the trabecular meshwork and is also known as trabecular meshwork glucocorticoid-inducible response protein. [7] |
article-22264_9 | Open Angle Glaucoma -- Etiology -- Genetic | Chromosome 5q22.1, WDR36 gene: The WDR36 protein is a member of the WD repeat protein family and is implicated in adult-onset POAG. This protein functions in ribosomal ribonucleic acid processing, p53 stress-pathway response, cell cycle progression, signal transduction, apoptosis, and gene regulation. WDR36 protein is expressed in the lens, iris, sclera, ciliary muscles, ciliary body, trabecular meshwork, retina, and optic nerve in the eye. The protein is also expressed outside the eye in the human heart, placenta, liver, skeletal muscle, kidney, and pancreas. Four mutations in WDR36 at the GLC1G locus ( N355S , A449T , R529Q , and D658G ) have been identified, with a study implicating the gene in approximately 6% of patients with POAG. However, results from a recent 2017 Chinese study repudiated this claim by showing that the association between WDR36 and POAG is inconsistent across populations and calls for more data supporting the WDR36 protein's role in POAG. [8] [9] | Open Angle Glaucoma -- Etiology -- Genetic. Chromosome 5q22.1, WDR36 gene: The WDR36 protein is a member of the WD repeat protein family and is implicated in adult-onset POAG. This protein functions in ribosomal ribonucleic acid processing, p53 stress-pathway response, cell cycle progression, signal transduction, apoptosis, and gene regulation. WDR36 protein is expressed in the lens, iris, sclera, ciliary muscles, ciliary body, trabecular meshwork, retina, and optic nerve in the eye. The protein is also expressed outside the eye in the human heart, placenta, liver, skeletal muscle, kidney, and pancreas. Four mutations in WDR36 at the GLC1G locus ( N355S , A449T , R529Q , and D658G ) have been identified, with a study implicating the gene in approximately 6% of patients with POAG. However, results from a recent 2017 Chinese study repudiated this claim by showing that the association between WDR36 and POAG is inconsistent across populations and calls for more data supporting the WDR36 protein's role in POAG. [8] [9] |
article-22264_10 | Open Angle Glaucoma -- Etiology -- Genetic | Chromosome 7q31, CAV1/CAV2 genes: CAV1 and CAV2 are protein members of the caveolin family that are involved in the formation of caveolae-invaginations of the plasma membrane in areas that are rich in cholesterol during transcytosis. This gene is associated with POAG susceptibility in populations of European and East Asian ancestry. CAV1 and CAV2 are expressed in most human cell types, including tissues such as the scleral spur cells, trabecular meshwork, and retinal ganglion cells. In vitro studies of CAV1 showed consistent upregulation in the trabecular meshwork after one hour of increased IOP. [10] [11] | Open Angle Glaucoma -- Etiology -- Genetic. Chromosome 7q31, CAV1/CAV2 genes: CAV1 and CAV2 are protein members of the caveolin family that are involved in the formation of caveolae-invaginations of the plasma membrane in areas that are rich in cholesterol during transcytosis. This gene is associated with POAG susceptibility in populations of European and East Asian ancestry. CAV1 and CAV2 are expressed in most human cell types, including tissues such as the scleral spur cells, trabecular meshwork, and retinal ganglion cells. In vitro studies of CAV1 showed consistent upregulation in the trabecular meshwork after one hour of increased IOP. [10] [11] |
article-22264_11 | Open Angle Glaucoma -- Etiology -- Genetic | Chromosome 9p21, CDKN2B-AS1 gene: CDKN2B-AS1 is a cyclin-dependent kinase inhibitor 2B antisense noncoding ribonucleic acid that regulates cyclin-dependent kinase inhibitor 2A and 2B in the cell cycle. [12] A United States-based observational case study found that this region modifies optic nerve vulnerability to glaucomatous change. Single nucleotide polymorphism (SNP) in this gene is thought to be implicated in POAG by causing RGCs to undergo apoptosis during their quiescent post-mitotic state. [13] [14] | Open Angle Glaucoma -- Etiology -- Genetic. Chromosome 9p21, CDKN2B-AS1 gene: CDKN2B-AS1 is a cyclin-dependent kinase inhibitor 2B antisense noncoding ribonucleic acid that regulates cyclin-dependent kinase inhibitor 2A and 2B in the cell cycle. [12] A United States-based observational case study found that this region modifies optic nerve vulnerability to glaucomatous change. Single nucleotide polymorphism (SNP) in this gene is thought to be implicated in POAG by causing RGCs to undergo apoptosis during their quiescent post-mitotic state. [13] [14] |
article-22264_12 | Open Angle Glaucoma -- Etiology -- Genetic | Chromosome 10p13, OPTN gene: Optineurin is the coiled-coil protein product implicated in adult-onset POAG and normal-tension glaucoma. Optineurin is involved in various cellular functions, including apoptosis, cellular morphogenesis, inflammation, vasoconstriction, membrane protein trafficking, vesicular trafficking, and transcription activation. [15] | Open Angle Glaucoma -- Etiology -- Genetic. Chromosome 10p13, OPTN gene: Optineurin is the coiled-coil protein product implicated in adult-onset POAG and normal-tension glaucoma. Optineurin is involved in various cellular functions, including apoptosis, cellular morphogenesis, inflammation, vasoconstriction, membrane protein trafficking, vesicular trafficking, and transcription activation. [15] |
article-22264_13 | Open Angle Glaucoma -- Etiology -- Genetic | Chromosome 15q24.1, LOXL1 gene: Lysyl oxidase-like 1 gene codes for an extracellular copper-dependent amine oxidase enzyme that catalyzes the first step in crosslinking collagen and elastin in the extracellular matrix and is implicated in cases of pseudoexfoliation syndrome. SNP in the LOXL1 gene is associated with excessive levels of crosslinked amyloid-like fibrillar glycoproteins that deposit in the anterior segment and are more common in Scandinavian populations. [16] [17] SNPs in the LOXL1 gene can present as exfoliation glaucoma as the first signs of a more systemic severe condition that implicates multiple tissues with the expression of this enzyme, including the liver, kidney, and gallbladder. [18] [19] | Open Angle Glaucoma -- Etiology -- Genetic. Chromosome 15q24.1, LOXL1 gene: Lysyl oxidase-like 1 gene codes for an extracellular copper-dependent amine oxidase enzyme that catalyzes the first step in crosslinking collagen and elastin in the extracellular matrix and is implicated in cases of pseudoexfoliation syndrome. SNP in the LOXL1 gene is associated with excessive levels of crosslinked amyloid-like fibrillar glycoproteins that deposit in the anterior segment and are more common in Scandinavian populations. [16] [17] SNPs in the LOXL1 gene can present as exfoliation glaucoma as the first signs of a more systemic severe condition that implicates multiple tissues with the expression of this enzyme, including the liver, kidney, and gallbladder. [18] [19] |
article-22264_14 | Open Angle Glaucoma -- Etiology -- Genetic | Several study results (based on whole-exome sequencing using gene-based and single-variant analyses) have revealed more than 40 new previously unreported genes associated with glaucoma phenotypes. [20] Understanding this disease's genetic and molecular mechanisms is crucial to developing new drug targets. [21] [22] | Open Angle Glaucoma -- Etiology -- Genetic. Several study results (based on whole-exome sequencing using gene-based and single-variant analyses) have revealed more than 40 new previously unreported genes associated with glaucoma phenotypes. [20] Understanding this disease's genetic and molecular mechanisms is crucial to developing new drug targets. [21] [22] |
article-22264_15 | Open Angle Glaucoma -- Epidemiology | Glaucoma affects about 70 million people worldwide and is the second leading cause of blindness globally. Of the 70 million individuals affected by glaucoma, 74% have OAG; in the United States (US), nearly 80% of all glaucoma is OAG. A recent meta-analysis showed that the estimated number of individuals with POAG worldwide is about 68.56 million, with more than 50% from Africa and Asia. [23] Nearly 10% of all patients with glaucoma are blind bilaterally; bilateral blindness due to OAG has been estimated to affect 5.9 million people in 2020. At least 2.7 million people ≥40 years are diagnosed with glaucoma in the US, and the number of patients with all forms of glaucoma worldwide is projected to rise. The highest prevalence of OAG is found in African-American populations. Glaucoma is the leading cause of blindness in African Americans, with prevalence in Latin American and Chinese individuals approaching in older patient populations. Women are disproportionately affected by all forms of glaucoma, comprising approximately 55.4% of all cases of OAG. | Open Angle Glaucoma -- Epidemiology. Glaucoma affects about 70 million people worldwide and is the second leading cause of blindness globally. Of the 70 million individuals affected by glaucoma, 74% have OAG; in the United States (US), nearly 80% of all glaucoma is OAG. A recent meta-analysis showed that the estimated number of individuals with POAG worldwide is about 68.56 million, with more than 50% from Africa and Asia. [23] Nearly 10% of all patients with glaucoma are blind bilaterally; bilateral blindness due to OAG has been estimated to affect 5.9 million people in 2020. At least 2.7 million people ≥40 years are diagnosed with glaucoma in the US, and the number of patients with all forms of glaucoma worldwide is projected to rise. The highest prevalence of OAG is found in African-American populations. Glaucoma is the leading cause of blindness in African Americans, with prevalence in Latin American and Chinese individuals approaching in older patient populations. Women are disproportionately affected by all forms of glaucoma, comprising approximately 55.4% of all cases of OAG. |
article-22264_16 | Open Angle Glaucoma -- Epidemiology | Longevity also plays a role because glaucoma primarily affects older populations. The longevity factor should be considered in the epidemiology of glaucoma, as women and individuals in developed countries have greater longevity than men and individuals in non-developed countries. In 2020, OAG was projected to have the highest prevalence rate in Europe, followed by China and India. [24] [25] | Open Angle Glaucoma -- Epidemiology. Longevity also plays a role because glaucoma primarily affects older populations. The longevity factor should be considered in the epidemiology of glaucoma, as women and individuals in developed countries have greater longevity than men and individuals in non-developed countries. In 2020, OAG was projected to have the highest prevalence rate in Europe, followed by China and India. [24] [25] |
article-22264_17 | Open Angle Glaucoma -- Epidemiology -- Risk Factors: | Older age (African American, 40+ years; Caucasians, 65+ years) [26] | Open Angle Glaucoma -- Epidemiology -- Risk Factors:. Older age (African American, 40+ years; Caucasians, 65+ years) [26] |
article-22264_18 | Open Angle Glaucoma -- Epidemiology -- Risk Factors: | Race (African-American, Afro-Caribbean, and West African patients have a 4-fold increased risk of developing OAG) [26] | Open Angle Glaucoma -- Epidemiology -- Risk Factors:. Race (African-American, Afro-Caribbean, and West African patients have a 4-fold increased risk of developing OAG) [26] |
article-22264_19 | Open Angle Glaucoma -- Epidemiology -- Risk Factors: | Family history (eg, the Rotterdam Eye study found a 9.2 times higher risk of developing OAG if first-degree relatives had glaucoma) [27] | Open Angle Glaucoma -- Epidemiology -- Risk Factors:. Family history (eg, the Rotterdam Eye study found a 9.2 times higher risk of developing OAG if first-degree relatives had glaucoma) [27] |
article-22264_20 | Open Angle Glaucoma -- Epidemiology -- Risk Factors: | Elevated IOP [28] | Open Angle Glaucoma -- Epidemiology -- Risk Factors:. Elevated IOP [28] |
article-22264_21 | Open Angle Glaucoma -- Epidemiology -- Risk Factors: | Myopia (eg, results from studies have reported an increased risk of glaucoma of up to 20% for each diopter increase in myopia) [29] | Open Angle Glaucoma -- Epidemiology -- Risk Factors:. Myopia (eg, results from studies have reported an increased risk of glaucoma of up to 20% for each diopter increase in myopia) [29] |
article-22264_22 | Open Angle Glaucoma -- Epidemiology -- Risk Factors: | Increased cup-to-disc ratio [30] | Open Angle Glaucoma -- Epidemiology -- Risk Factors:. Increased cup-to-disc ratio [30] |
article-22264_23 | Open Angle Glaucoma -- Epidemiology -- Risk Factors: | Disc hemorrhage [31] | Open Angle Glaucoma -- Epidemiology -- Risk Factors:. Disc hemorrhage [31] |
article-22264_24 | Open Angle Glaucoma -- Epidemiology -- Risk Factors: | Thin central corneal thickness [32] | Open Angle Glaucoma -- Epidemiology -- Risk Factors:. Thin central corneal thickness [32] |
article-22264_25 | Open Angle Glaucoma -- Epidemiology -- Risk Factors: | Low ocular perfusion pressure [33] | Open Angle Glaucoma -- Epidemiology -- Risk Factors:. Low ocular perfusion pressure [33] |
article-22264_26 | Open Angle Glaucoma -- Epidemiology -- Risk Factors: | Low blood pressure (systolic and diastolic) [34] | Open Angle Glaucoma -- Epidemiology -- Risk Factors:. Low blood pressure (systolic and diastolic) [34] |
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