Browse the corpus

High-Altitude-Related lllnesses hospital discharge until the patient can be evaluated with IEY P0lill po$somnography and titrated with the appropriate positive o Noninvasive positive pressure ventilation devices are pressure support. Supplemental oxygen may need to be added. often prescribed to alleviate sleep-related symptoms f,TY POI]IT and support blood oxygen levels in patients with neuro- . The hallmark of obesity hlpoventilation syndrome is muscular disorders. daytime hypercapnia, defined as an arterial Pco, greater than 45 mm Hg (s.9 kPa).

hospital discharge until the patient can be evaluated with IEY P0lill po$somnography and titrated with the appropriate positive o Noninvasive positive pressure ventilation devices are pressure support. Supplemental oxygen may need to be added. often prescribed to alleviate sleep-related symptoms f,TY POI]IT and support blood oxygen levels in patients with neuro- . The hallmark of obesity hlpoventilation syndrome is muscular disorders. daytime hypercapnia, defined as an arterial Pco, greater than 45 mm Hg (s.9 kPa). H i g h-Altitu d e- Re lated Neuromuscular Diseases Noninvasive positive pressure ventilation devices are often lllnesses prescribed to alleviate sleep-related symptoms and support blood oxygen levels in patients with neuromuscular disorders Pathogenesis of Hig h-Altitude (Table 39). Bilevel positive airway pressure or volume-assured lllness devices (average volume-assured pressure support), either Diminishing barometric pressure associated r,r'ith an ascent to with or without supplemental oxygen, are indicated once altitude reduces the amount of ambient oxygen available there is evidence of daytime hypercapnia indicative of chronic for gas exchange, a condition known as hypobaric hypoxia. respiratory failure. Polysomnography may aid in optimizing Physiologic responses to hypobaric hypoxia mechanistically machine and oxygen settings and in assessing concomitant underlie many disorders collectively referred to as high sleep disorders, but it is not always needed. Tracheostomy and altitude illness (Table 40). Susceptibility to high altitude home mechanical ventilation are effective and may be appro illness is individualized and difficult to predict. Although priate for some patients. Supplemental oxygen may further high altitude illnesses can occur at all ages regardless ol fit depress ventilation in patients with respiratory muscle weak ness level, patients with a history ol high altitude-related ness and should generally not be prescribed without adjunc illness are at risk for recurrence. Other risk factors include tive ventilatory support, either by noninvasive means or by rapid ascent (more than 3500 m in less than 2 days or more tracheostomy. than 500 m per day above altitudes of 3000 m) and medical comorbidities that impair oxygenation. such as interstitial lung TABLE 39. Positive Airway Pressure Modes disease, COPD, and pulmonary hypertension. Acetazolamide

H i g h-Altitu d e- Re lated Neuromuscular Diseases Noninvasive positive pressure ventilation devices are often lllnesses prescribed to alleviate sleep-related symptoms and support blood oxygen levels in patients with neuromuscular disorders Pathogenesis of Hig h-Altitude (Table 39). Bilevel positive airway pressure or volume-assured lllness devices (average volume-assured pressure support), either Diminishing barometric pressure associated r,r'ith an ascent to with or without supplemental oxygen, are indicated once altitude reduces the amount of ambient oxygen available there is evidence of daytime hypercapnia indicative of chronic for gas exchange, a condition known as hypobaric hypoxia. respiratory failure. Polysomnography may aid in optimizing Physiologic responses to hypobaric hypoxia mechanistically machine and oxygen settings and in assessing concomitant underlie many disorders collectively referred to as high sleep disorders, but it is not always needed. Tracheostomy and altitude illness (Table 40). Susceptibility to high altitude home mechanical ventilation are effective and may be appro illness is individualized and difficult to predict. Although priate for some patients. Supplemental oxygen may further high altitude illnesses can occur at all ages regardless ol fit depress ventilation in patients with respiratory muscle weak ness level, patients with a history ol high altitude-related ness and should generally not be prescribed without adjunc illness are at risk for recurrence. Other risk factors include tive ventilatory support, either by noninvasive means or by rapid ascent (more than 3500 m in less than 2 days or more tracheostomy. than 500 m per day above altitudes of 3000 m) and medical comorbidities that impair oxygenation. such as interstitial lung TABLE 39. Positive Airway Pressure Modes disease, COPD, and pulmonary hypertension. Acetazolamide Mode Description lndication and gradual ascent to altitude can be used prophylactically in patients who have previously suffered high altitude illness or CPAP Fixed pressure derived from OSA have other risk factors. an in-lab titration attended by Occasionally CSA a technician f,EY POI]II APAP Range of pressure delivered OSA o Acetazolamide and gradual ascent to altitude can be HVC to maintain upper airway patency, determined by a used prophylactically in patients who have previously proprietary computer suffered high-altitude illness or have other risk factors. algorithm BPAP lnspiratory pressure support Hypoventilation delivered over and above a minimum expiratory syndromes Acute Mountain Sickness OSAwhen CPAP pressure, derived from an fails (including Cerebral blood flow and oxygen delivery to the brain are in-lab titration patient intolerance) altered by the hypoxia and hypocapnia associated with the Auto- Range of bilevel pressures Same as BPAP ascent to altitude. In acute mountain sickness-the most com BPAP determined by a proprietary mon high altitude illness-symptoms are nonspecific and computer algorithm include headache, fatigue, nausea. and vomiting: disturbed ASV Breath-by-breath adjustment CSA (including sleep related to high-altitude periodic breathing is also com of inspiratory pressure mixed CSA and mon. Cerebral autoregulatory mechanisms can dampen the support and back-up rate OSA); do not use determined by a proprietary in patients with stress on blood flow resulting in mild symptoms. Acute moun computer algorithm; heart failure with tain sickness is estimated to affect as many as 25'l. of visitors to expiratory pressure set by a reduced ejection an altitude of 2000 m, the elevation at most majorwestern U.S. technician fraction ski areas. Healy exertion and dehydration tend to amplify Auto- nspiratory and expiratory I Same as ASV ASV pressures determined by a symptoms, which, provided there is no further ascent. typi proprietary algorithm cally resolve within 24 to 48 hours. Treatment and prevention APAP - auto adjusting positive aimay pressure; ASV = adaptive setuo ventilation; approaches are shown in Table 40. BPAP = bilevel positive airway pressure; CPAP = continuous positive aiMay pressure; In high-altitude periodic breathing, chemoreceptors CSA = central sleep apnea; OSA = obstructive sleep apnea. that are sensitive to hypoxia increase ventilation. This drives

Mode Description lndication and gradual ascent to altitude can be used prophylactically in patients who have previously suffered high altitude illness or CPAP Fixed pressure derived from OSA have other risk factors. an in-lab titration attended by Occasionally CSA a technician f,EY POI]II APAP Range of pressure delivered OSA o Acetazolamide and gradual ascent to altitude can be HVC to maintain upper airway patency, determined by a used prophylactically in patients who have previously proprietary computer suffered high-altitude illness or have other risk factors. algorithm BPAP lnspiratory pressure support Hypoventilation delivered over and above a minimum expiratory syndromes Acute Mountain Sickness OSAwhen CPAP pressure, derived from an fails (including Cerebral blood flow and oxygen delivery to the brain are in-lab titration patient intolerance) altered by the hypoxia and hypocapnia associated with the Auto- Range of bilevel pressures Same as BPAP ascent to altitude. In acute mountain sickness-the most com BPAP determined by a proprietary mon high altitude illness-symptoms are nonspecific and computer algorithm include headache, fatigue, nausea. and vomiting: disturbed ASV Breath-by-breath adjustment CSA (including sleep related to high-altitude periodic breathing is also com of inspiratory pressure mixed CSA and mon. Cerebral autoregulatory mechanisms can dampen the support and back-up rate OSA); do not use determined by a proprietary in patients with stress on blood flow resulting in mild symptoms. Acute moun computer algorithm; heart failure with tain sickness is estimated to affect as many as 25'l. of visitors to expiratory pressure set by a reduced ejection an altitude of 2000 m, the elevation at most majorwestern U.S. technician fraction ski areas. Healy exertion and dehydration tend to amplify Auto- nspiratory and expiratory I Same as ASV ASV pressures determined by a symptoms, which, provided there is no further ascent. typi proprietary algorithm cally resolve within 24 to 48 hours. Treatment and prevention APAP - auto adjusting positive aimay pressure; ASV = adaptive setuo ventilation; approaches are shown in Table 40. BPAP = bilevel positive airway pressure; CPAP = continuous positive aiMay pressure; In high-altitude periodic breathing, chemoreceptors CSA = central sleep apnea; OSA = obstructive sleep apnea. that are sensitive to hypoxia increase ventilation. This drives 56

High-Altitude-Related lllnesses TABTE 40. Spectrum of High-Altitude lllness Syndromes High-Altitude lllness Elevation Level Symptoms Treatment Prevention Acute mountain 2000-2500 m Nonspecific; include Oxygen, acetazolamide, Gradual ascent (<500 m/d) at sickness headache, malaise, dexamethasone, descent high altitude; prophylaxis anorexia, nausea, from altitude, aspirin or with acetazolamide or vomiting NSAID for headache dexamethasone in rapid ascent or patients at high risk High-altitude cerebral 3000 4000 m Confusion, irritabil ity, Descent from altitude, Gradual ascent; consider edema ataxic gait, coma, death supplemental oxygen, acetazolamide or hyperbaric therapy dexamethasone in patients at high risk High-altitude >2500 m Cough, exertional Supplemental oxygen and Gradual ascent; consider pulmonary edema intolerance, dyspnea descent from altitude; nifedipine in patients at at rest adjunctive therapy: high risk nifedipine, PDE-5 inhibitors (2-4 d after arrival at new altitude) Diuretics and nitrates not recommended lntubation may be required

High-altitude >2500 m Cough, exertional Supplemental oxygen and Gradual ascent; consider pulmonary edema intolerance, dyspnea descent from altitude; nifedipine in patients at at rest adjunctive therapy: high risk nifedipine, PDE-5 inhibitors (2-4 d after arrival at new altitude) Diuretics and nitrates not recommended lntubation may be required arterial Pco, toward the apneic threshold and results in a pause High-Altitude Pulmonary Edema in breathing (central apnea) when the threshold is crossed. The pulmonary vasculature constricts in response to hypoxia, With this pause, arterial Pcoz eventually rises sufficiently to resulting in increases in pulmonary vascular resistance. An again stimulate breathing. The cycle of ventilatory overshoot, exaggerated increase in pulmonary artery pressure is associated hypocapnia, and central apneas repeats at night. Patients com- with high-altitude pulmonary edema. High altitude pulmonary plain of interrupted sleep and insomnia and may experience edema is uncommon but can be life threatening. Patients are paroxysms of dyspnea that awaken them. Alcohol ingestion, olten tachypneic and tachycardic, and crackles or wheezing can which promotes dehydration, can intensify the sequelae of be heard on chest examination. Pink, frothy sputum or frank high altitude periodic breathing. hemoptysis may occur, which heralds worsening gas exchange I(EY PO I ilI and respiratory failure. The treatment of choice is supplemental . Symptoms of acute mountain sickness are nonspeciflc oxygen along with rest, both of which will acutely reduce pul and include headache, fatigue, nausea, and vomiting; monary artery pressures. Descent from altitude should be con disturbed sleep related to high-altitude periodic breath sidered. See Table 40 for other adjunctive therapies. ing is common. Air Travel in Pulmonary Disease The principles of hypobaric hypoxia also apply to commercial High-Altitude Cerebral Edema airline travel. Cabins are pressurized to the equivalent of1500 to 2500 m (approximately 5000 8000 ft) in altitude, resulting When the cerebral compensatory pathways are overwhelmed, severe, life threatening cerebral edema can ensue. High- in an inspired oxygen tension between 110 and 120 mm Hg (about 70'1, of the levels encountered at sea level). The result altitude cerebral edema is a feared manifestation of acute mountain sickness that tends to occur at higher elevations ant arterial Po, of approximately 60 mm Hg (8.0 kPa) is (above 3000 m). Recognition of cerebral edema mandates adequate for healthy individuals, but those with underlying pulmonary disease are at risk for significant hypoxemia dur immediate intervention. Definitive treatment is immediate ing flight (Table al). descent from altitude, particularly when the patient is still ambulatory, because incapacitation at high altitude exponen- TABTE 41 . Risk Factors for Air Travel in Pulmonary Disease tiel ly compliciltes evucuirt ion. Risk Factor I(EY POI l{T Advanced COPD complicated by hypercapnic respiratory failure o Definitive treatment of high-altitude cerebral edema Pulmonary hypertension is immediate descent from altitude, particularly Restrictive lung disease when the patient is still ambulatory, because inca- pacitation at high altitude exponentially complicates Recent exacerbation of chronic lung disease

arterial Pco, toward the apneic threshold and results in a pause High-Altitude Pulmonary Edema in breathing (central apnea) when the threshold is crossed. The pulmonary vasculature constricts in response to hypoxia, With this pause, arterial Pcoz eventually rises sufficiently to resulting in increases in pulmonary vascular resistance. An again stimulate breathing. The cycle of ventilatory overshoot, exaggerated increase in pulmonary artery pressure is associated hypocapnia, and central apneas repeats at night. Patients com- with high-altitude pulmonary edema. High altitude pulmonary plain of interrupted sleep and insomnia and may experience edema is uncommon but can be life threatening. Patients are paroxysms of dyspnea that awaken them. Alcohol ingestion, olten tachypneic and tachycardic, and crackles or wheezing can which promotes dehydration, can intensify the sequelae of be heard on chest examination. Pink, frothy sputum or frank high altitude periodic breathing. hemoptysis may occur, which heralds worsening gas exchange I(EY PO I ilI and respiratory failure. The treatment of choice is supplemental . Symptoms of acute mountain sickness are nonspeciflc oxygen along with rest, both of which will acutely reduce pul and include headache, fatigue, nausea, and vomiting; monary artery pressures. Descent from altitude should be con disturbed sleep related to high-altitude periodic breath sidered. See Table 40 for other adjunctive therapies. ing is common. Air Travel in Pulmonary Disease The principles of hypobaric hypoxia also apply to commercial High-Altitude Cerebral Edema airline travel. Cabins are pressurized to the equivalent of1500 to 2500 m (approximately 5000 8000 ft) in altitude, resulting When the cerebral compensatory pathways are overwhelmed, severe, life threatening cerebral edema can ensue. High- in an inspired oxygen tension between 110 and 120 mm Hg (about 70'1, of the levels encountered at sea level). The result altitude cerebral edema is a feared manifestation of acute mountain sickness that tends to occur at higher elevations ant arterial Po, of approximately 60 mm Hg (8.0 kPa) is (above 3000 m). Recognition of cerebral edema mandates adequate for healthy individuals, but those with underlying pulmonary disease are at risk for significant hypoxemia dur immediate intervention. Definitive treatment is immediate ing flight (Table al). descent from altitude, particularly when the patient is still ambulatory, because incapacitation at high altitude exponen- TABTE 41 . Risk Factors for Air Travel in Pulmonary Disease tiel ly compliciltes evucuirt ion. Risk Factor I(EY POI l{T Advanced COPD complicated by hypercapnic respiratory failure o Definitive treatment of high-altitude cerebral edema Pulmonary hypertension is immediate descent from altitude, particularly Restrictive lung disease when the patient is still ambulatory, because inca- pacitation at high altitude exponentially complicates Recent exacerbation of chronic lung disease evacuation. History of previous in-flight symptoms

arterial Pco, toward the apneic threshold and results in a pause High-Altitude Pulmonary Edema in breathing (central apnea) when the threshold is crossed. The pulmonary vasculature constricts in response to hypoxia, With this pause, arterial Pcoz eventually rises sufficiently to resulting in increases in pulmonary vascular resistance. An again stimulate breathing. The cycle of ventilatory overshoot, exaggerated increase in pulmonary artery pressure is associated hypocapnia, and central apneas repeats at night. Patients com- with high-altitude pulmonary edema. High altitude pulmonary plain of interrupted sleep and insomnia and may experience edema is uncommon but can be life threatening. Patients are paroxysms of dyspnea that awaken them. Alcohol ingestion, olten tachypneic and tachycardic, and crackles or wheezing can which promotes dehydration, can intensify the sequelae of be heard on chest examination. Pink, frothy sputum or frank high altitude periodic breathing. hemoptysis may occur, which heralds worsening gas exchange I(EY PO I ilI and respiratory failure. The treatment of choice is supplemental . Symptoms of acute mountain sickness are nonspeciflc oxygen along with rest, both of which will acutely reduce pul and include headache, fatigue, nausea, and vomiting; monary artery pressures. Descent from altitude should be con disturbed sleep related to high-altitude periodic breath sidered. See Table 40 for other adjunctive therapies. ing is common. Air Travel in Pulmonary Disease The principles of hypobaric hypoxia also apply to commercial High-Altitude Cerebral Edema airline travel. Cabins are pressurized to the equivalent of1500 to 2500 m (approximately 5000 8000 ft) in altitude, resulting When the cerebral compensatory pathways are overwhelmed, severe, life threatening cerebral edema can ensue. High- in an inspired oxygen tension between 110 and 120 mm Hg (about 70'1, of the levels encountered at sea level). The result altitude cerebral edema is a feared manifestation of acute mountain sickness that tends to occur at higher elevations ant arterial Po, of approximately 60 mm Hg (8.0 kPa) is (above 3000 m). Recognition of cerebral edema mandates adequate for healthy individuals, but those with underlying pulmonary disease are at risk for significant hypoxemia dur immediate intervention. Definitive treatment is immediate ing flight (Table al). descent from altitude, particularly when the patient is still ambulatory, because incapacitation at high altitude exponen- TABTE 41 . Risk Factors for Air Travel in Pulmonary Disease tiel ly compliciltes evucuirt ion. Risk Factor I(EY POI l{T Advanced COPD complicated by hypercapnic respiratory failure o Definitive treatment of high-altitude cerebral edema Pulmonary hypertension is immediate descent from altitude, particularly Restrictive lung disease when the patient is still ambulatory, because inca- pacitation at high altitude exponentially complicates Recent exacerbation of chronic lung disease evacuation. History of previous in-flight symptoms 57

Critical Care Medicine: ICU Utilization TABLE 42, Preflight Screening in Chronic Lung Disease compare disease severiry progression, and outcomes. Disease- specific scoring systems can also be used to triage patients on Oxygen Saturation" Recommendation the basis of risk for deterioration or death. Examples include <92o/" ln-flight oxygen (typically the simplified Pulmonary Embolism Severity Index, the quick 2-3 Umin) Sequential Organ Failure Assessment for sepsis. and the 920/"-950/" Hypoxia altitude simulation testing Pneumonia Severity Index or the CURB 65 for predicting mortality in community acquired pneumonia. The electronic Already receiving long-term Double flow rate during flight oxygen medical record databases are being harnessed to provide warning and predictive systems based on usually collected , 'By pulse oximetry at sea level data (vital signs. age, and current or trending clinical informa tion) to identify at risk patients. Predictive models are evolv- The risk for pneumothorax in air travel is low as airline ing with the application of machine learning and artificial cabins are pressurized. In patients with chronic lung disease intelligence, yet their application remains at local levels and is (such as asthma or COPD), signs or symptoms indicative of a not widespread. pneumothorax (acute chest pain, dyspnea) should prompt the in flight administration of supplemental oxygen, which pro motes resorption of pleural air. For patients with chronic lung Organization of Critical Care disease associated with hypoxia, preflight evaluation to deter To improve early management and resuscitation ol patients mine recommended oxygen use is helpful (Table 42). who are at risk or deteriorating. many health care systems After cardiothoracic surgery a delay of 3 to 4 weeks befbre have developed rapid response teams or medical emergency air travel is reasonable. An existing pneumothorax has tradi response teams, with the aim of recognizing patients promptly. tionally been considered a contraindication to flight because triggering early evaluation and management. and moving the of the potential risk fbr expansion and tension physiologr. Air patient to a higher level of care. A key element of this system is travel may be safe in the presence of a small postoperative the ability fbr any member of the health care team or family pneumothorax that has been radiographically stable. member to trigger the rapid response team. Systematic revieu,s TEY POIXIS and meta analyses of the effectiveness of these teams demon- o Pulse oximetry is a useful screening tool for patients strate a variable decrease in cardiac and respiratory arrests. who have chronic lung disease, with which an oxy- unexpected deterioration, and mortality in adults. hemoglobin saturation of less than 92"/,, atsea level indi Determining admission to a critical care bed is more com- plicated than simply assessing the level of patient illness. lt is cates a likely need for in flight supplemental oxygen. determined in a significant way by hospital and unit policies HVC . During air travel, doubling the flow rate is typically and resources unique to each institution. No standard admis adequate for patients who are already receiving long- sion model exists, although international societies have pub term supplemental oxygen. lished guidelines. Hospitals have developed institution specific protocols to befter manage patients who require life-support technologr. Critical Care Medicine: An ICU is equipped with technolory that allor,r,s continu ous patient monitoring and delivery of life sustaining inter ICU Utilization ventions such as mechanical ventilation and emergency extracorporeal organ support. Hospital units designated as Recognizing the ICUs typically have the sickest patients and require nurse to- Critically lll Patient patient ratios of1:1 or 1:2, whereas a progressive care unit (also There are no commonly accepted criteria for admission to an called an intermediate, transitional. or step down unit) may lCU. Signs and symptoms of clinical instability, including have a nurse to patient ratio as high as 1:5. reflecting patients hypotension, hypoxemia, arrhythmias. and changes in mental with lower acuity. status, may be useful in identilying patients who require Critical care is generally defined as open unit versus intense resources or may be at risk for deterioration. Several closed unit and low intensity versus high intensity. In an open scoring systems, such as the Acute Physiologr and Chronic unit, patients are managed by their primary hospital team. Health Evaluation, the Sequential Organ Failure Assessment, which may or may not include a critical care consultant. and the Simplified Acute Physiologr Score, have been designed Patients in a closed unit are managed primarily by the critical to help classify the severity ol disease of patients admitted to care team. Low intensity units are open units. Although high the ICU. These scoring systems use vital signs and risk factors intensity units can be open or closed units. the critical care such as chronic disease, emergent surgery and immunosup team is present throughout the day. providing consultation. pression to calculate risk for mortality. Although they are Data supporting high intensity and closed models with con- rarely, if ever, used as ICU admission criteria, they are used to tinuous staffing of ICUs by intensivists have been conflicting;

TABLE 42, Preflight Screening in Chronic Lung Disease compare disease severiry progression, and outcomes. Disease- specific scoring systems can also be used to triage patients on Oxygen Saturation" Recommendation the basis of risk for deterioration or death. Examples include <92o/" ln-flight oxygen (typically the simplified Pulmonary Embolism Severity Index, the quick 2-3 Umin) Sequential Organ Failure Assessment for sepsis. and the 920/"-950/" Hypoxia altitude simulation testing Pneumonia Severity Index or the CURB 65 for predicting mortality in community acquired pneumonia. The electronic Already receiving long-term Double flow rate during flight oxygen medical record databases are being harnessed to provide warning and predictive systems based on usually collected , 'By pulse oximetry at sea level data (vital signs. age, and current or trending clinical informa tion) to identify at risk patients. Predictive models are evolv- The risk for pneumothorax in air travel is low as airline ing with the application of machine learning and artificial cabins are pressurized. In patients with chronic lung disease intelligence, yet their application remains at local levels and is (such as asthma or COPD), signs or symptoms indicative of a not widespread. pneumothorax (acute chest pain, dyspnea) should prompt the in flight administration of supplemental oxygen, which pro motes resorption of pleural air. For patients with chronic lung Organization of Critical Care disease associated with hypoxia, preflight evaluation to deter To improve early management and resuscitation ol patients mine recommended oxygen use is helpful (Table 42). who are at risk or deteriorating. many health care systems After cardiothoracic surgery a delay of 3 to 4 weeks befbre have developed rapid response teams or medical emergency air travel is reasonable. An existing pneumothorax has tradi response teams, with the aim of recognizing patients promptly. tionally been considered a contraindication to flight because triggering early evaluation and management. and moving the of the potential risk fbr expansion and tension physiologr. Air patient to a higher level of care. A key element of this system is travel may be safe in the presence of a small postoperative the ability fbr any member of the health care team or family pneumothorax that has been radiographically stable. member to trigger the rapid response team. Systematic revieu,s TEY POIXIS and meta analyses of the effectiveness of these teams demon- o Pulse oximetry is a useful screening tool for patients strate a variable decrease in cardiac and respiratory arrests. who have chronic lung disease, with which an oxy- unexpected deterioration, and mortality in adults. hemoglobin saturation of less than 92"/,, atsea level indi Determining admission to a critical care bed is more com- plicated than simply assessing the level of patient illness. lt is cates a likely need for in flight supplemental oxygen. determined in a significant way by hospital and unit policies HVC . During air travel, doubling the flow rate is typically and resources unique to each institution. No standard admis adequate for patients who are already receiving long- sion model exists, although international societies have pub term supplemental oxygen. lished guidelines. Hospitals have developed institution specific protocols to befter manage patients who require life-support technologr. Critical Care Medicine: An ICU is equipped with technolory that allor,r,s continu ous patient monitoring and delivery of life sustaining inter ICU Utilization ventions such as mechanical ventilation and emergency extracorporeal organ support. Hospital units designated as Recognizing the ICUs typically have the sickest patients and require nurse to- Critically lll Patient patient ratios of1:1 or 1:2, whereas a progressive care unit (also There are no commonly accepted criteria for admission to an called an intermediate, transitional. or step down unit) may lCU. Signs and symptoms of clinical instability, including have a nurse to patient ratio as high as 1:5. reflecting patients hypotension, hypoxemia, arrhythmias. and changes in mental with lower acuity. status, may be useful in identilying patients who require Critical care is generally defined as open unit versus intense resources or may be at risk for deterioration. Several closed unit and low intensity versus high intensity. In an open scoring systems, such as the Acute Physiologr and Chronic unit, patients are managed by their primary hospital team. Health Evaluation, the Sequential Organ Failure Assessment, which may or may not include a critical care consultant. and the Simplified Acute Physiologr Score, have been designed Patients in a closed unit are managed primarily by the critical to help classify the severity ol disease of patients admitted to care team. Low intensity units are open units. Although high the ICU. These scoring systems use vital signs and risk factors intensity units can be open or closed units. the critical care such as chronic disease, emergent surgery and immunosup team is present throughout the day. providing consultation. pression to calculate risk for mortality. Although they are Data supporting high intensity and closed models with con- rarely, if ever, used as ICU admission criteria, they are used to tinuous staffing of ICUs by intensivists have been conflicting; 58

Principles of Critical Care recent data, however, show a mortalify benefit with the Sedation and Analgesia closed [CU. ICU patients often require sedation and analgesia. The need for The nature ofthe intensive care unit requires an interpro analgesia should be monitored at least every 4 hours. Pain fessional and multidisciplinary team. Key features that allow the should be assessed using an objective scale. Table 43 outlines best team dynamics are the explicit recognition of the roles and current guideline recommendations fbr analgesia and seda- responsibilities of the team members, the use of shared com- tion, emphasizing multimodal therapy to manage pain. munication models, and an environment of psychological safety. Opiates remain the mainstay, yet concurrent interventions can XEY POI]ITS reduce medication doses and improve pain control. Preemptive analgesia should be provided for painful procedures (e.g., arte- . Rapid response teams have been shown to decrease the rial line, thoracostomy tubes). incidence of cardiac and respiratory arrests as well as Sedation is commonly needed during invasive mechani- hospital mortality in adults. cal ventilation. Similar to analgesia, it requires monitoring HVC . Data supporting high-intensity and closed models of and should be objectively assessed using a scale (e.g., critical care with continuous staffing of ICUs by inten- Richmond Agitation Sedation Scale). Guidelines favor light sivists have been conflictingi recent data, however, show sedation. often achieved with intermittent use of opiates. In a mortality benefit with the closed ICU. patients who require continuous sedation, propofol or dex- medetomidine are pref'erred to benzodiazepines (associated Principles of Critical Care TABLE 43. 5ummary of Analgesia and Sedation Comprehensive Support Recommendations for Critical Care Patients

recent data, however, show a mortalify benefit with the Sedation and Analgesia closed [CU. ICU patients often require sedation and analgesia. The need for The nature ofthe intensive care unit requires an interpro analgesia should be monitored at least every 4 hours. Pain fessional and multidisciplinary team. Key features that allow the should be assessed using an objective scale. Table 43 outlines best team dynamics are the explicit recognition of the roles and current guideline recommendations fbr analgesia and seda- responsibilities of the team members, the use of shared com- tion, emphasizing multimodal therapy to manage pain. munication models, and an environment of psychological safety. Opiates remain the mainstay, yet concurrent interventions can XEY POI]ITS reduce medication doses and improve pain control. Preemptive analgesia should be provided for painful procedures (e.g., arte- . Rapid response teams have been shown to decrease the rial line, thoracostomy tubes). incidence of cardiac and respiratory arrests as well as Sedation is commonly needed during invasive mechani- hospital mortality in adults. cal ventilation. Similar to analgesia, it requires monitoring HVC . Data supporting high-intensity and closed models of and should be objectively assessed using a scale (e.g., critical care with continuous staffing of ICUs by inten- Richmond Agitation Sedation Scale). Guidelines favor light sivists have been conflictingi recent data, however, show sedation. often achieved with intermittent use of opiates. In a mortality benefit with the closed ICU. patients who require continuous sedation, propofol or dex- medetomidine are pref'erred to benzodiazepines (associated Principles of Critical Care TABLE 43. 5ummary of Analgesia and Sedation Comprehensive Support Recommendations for Critical Care Patients of Critically lll Patients Analgesia Recommendations

recent data, however, show a mortalify benefit with the Sedation and Analgesia closed [CU. ICU patients often require sedation and analgesia. The need for The nature ofthe intensive care unit requires an interpro analgesia should be monitored at least every 4 hours. Pain fessional and multidisciplinary team. Key features that allow the should be assessed using an objective scale. Table 43 outlines best team dynamics are the explicit recognition of the roles and current guideline recommendations fbr analgesia and seda- responsibilities of the team members, the use of shared com- tion, emphasizing multimodal therapy to manage pain. munication models, and an environment of psychological safety. Opiates remain the mainstay, yet concurrent interventions can XEY POI]ITS reduce medication doses and improve pain control. Preemptive analgesia should be provided for painful procedures (e.g., arte- . Rapid response teams have been shown to decrease the rial line, thoracostomy tubes). incidence of cardiac and respiratory arrests as well as Sedation is commonly needed during invasive mechani- hospital mortality in adults. cal ventilation. Similar to analgesia, it requires monitoring HVC . Data supporting high-intensity and closed models of and should be objectively assessed using a scale (e.g., critical care with continuous staffing of ICUs by inten- Richmond Agitation Sedation Scale). Guidelines favor light sivists have been conflictingi recent data, however, show sedation. often achieved with intermittent use of opiates. In a mortality benefit with the closed ICU. patients who require continuous sedation, propofol or dex- medetomidine are pref'erred to benzodiazepines (associated Principles of Critical Care TABLE 43. 5ummary of Analgesia and Sedation Comprehensive Support Recommendations for Critical Care Patients of Critically lll Patients Analgesia Recommendations Critical care teams often include pharmacists, respiratory Non pha rmacolog ic

recent data, however, show a mortalify benefit with the Sedation and Analgesia closed [CU. ICU patients often require sedation and analgesia. The need for The nature ofthe intensive care unit requires an interpro analgesia should be monitored at least every 4 hours. Pain fessional and multidisciplinary team. Key features that allow the should be assessed using an objective scale. Table 43 outlines best team dynamics are the explicit recognition of the roles and current guideline recommendations fbr analgesia and seda- responsibilities of the team members, the use of shared com- tion, emphasizing multimodal therapy to manage pain. munication models, and an environment of psychological safety. Opiates remain the mainstay, yet concurrent interventions can XEY POI]ITS reduce medication doses and improve pain control. Preemptive analgesia should be provided for painful procedures (e.g., arte- . Rapid response teams have been shown to decrease the rial line, thoracostomy tubes). incidence of cardiac and respiratory arrests as well as Sedation is commonly needed during invasive mechani- hospital mortality in adults. cal ventilation. Similar to analgesia, it requires monitoring HVC . Data supporting high-intensity and closed models of and should be objectively assessed using a scale (e.g., critical care with continuous staffing of ICUs by inten- Richmond Agitation Sedation Scale). Guidelines favor light sivists have been conflictingi recent data, however, show sedation. often achieved with intermittent use of opiates. In a mortality benefit with the closed ICU. patients who require continuous sedation, propofol or dex- medetomidine are pref'erred to benzodiazepines (associated Principles of Critical Care TABLE 43. 5ummary of Analgesia and Sedation Comprehensive Support Recommendations for Critical Care Patients of Critically lll Patients Analgesia Recommendations Critical care teams often include pharmacists, respiratory Non pha rmacolog ic therapists, physical or occupational therapists. advanced prac Music therapy tice providers, case managers, and social workers in addition Local cold therapy for procedures to nurses and physicians. The goals of care are generally to Massage therapy restore health and allow the patient to return home while Daily sedation interruption minimizing time in the hospital, medical complications, and Relaxation therapy long term effects of critical illness. In cases of overwhelming or irreversible disease, goals ofcare may change to providing lnvolve family

therapists, physical or occupational therapists. advanced prac Music therapy tice providers, case managers, and social workers in addition Local cold therapy for procedures to nurses and physicians. The goals of care are generally to Massage therapy restore health and allow the patient to return home while Daily sedation interruption minimizing time in the hospital, medical complications, and Relaxation therapy long term effects of critical illness. In cases of overwhelming or irreversible disease, goals ofcare may change to providing lnvolve family comlbrt and dignity at the end of lil'e. Pharmacologic Patients in the ICU are at risk of developing many hospital Opiates remain as the mainstay therapy acquired conditions. The most common are health care- Multimodal therapy (nonpharmacologic and nonopiate) associated infections. skin and soft tissue pressure injury Consider opiate reduction strateg ies malnutrition, gastrointestinal bleeding, delirium, and weakness Adjunct acetaminophen (see MKSAP 19 Infectious Disease for informaticln on health care associated infections). Protocolized care can improve safety Adjunct low-dose ketamine for postsurgical patients and decrease the incidence ofthese conditions. Adjunct gabapentin, carbamazepine, or pregabalin for nonneuropathic pain Protocols used in the ICU should be evidence based and periodically reviewed to ensure accuracy. For instance, stress Preprocedural pain management with opiate or NSAID ulcer prophylaxis with acid suppression has been standard Sedation Recommendations practice for all patients receiving mechanical ventilation. Use light sedation ratherthan deep sedation in mechanically Randomized trials evaluating acid suppression compared with ventilated patients placebo in patients who are at risk fbund decreased incidence Use sedation protocols of clinically significant bleeding, but no difference in mortality. Nurse-driven protocol There was no difference in the incidence of pneumonia or Daily sedation interruption Clostridioides difficile infection. To this effect, practice guide Favor use of propofol or dexmedetomidine over lines give a weak recommendation to stress ulcer prophylaxis benzodiazepines in those at high risk (i.e., patients with coagulopathy or chronic Use an objective scale to titrate sedation liver disease or who are receiving mechanical ventilation). Use a bispectral index monitor to assess sedation when scales The complexity of disease and interventions in a critically cannot be used (e.g., neuromuscular blockers) ill patient requires a methodical approach to daily care such as Data from Devlin JW, Skrobik Y, G6linas C, et al. C inical practlce quidelines for the the organ system based approach, which allows caregivers to prevention and management of pain, agitation/sedation, delirium, immobility, and review the main disease process, afT'ected organs and systems, sleep disruption in adult patients in the lCU. Crit Care Med. 201 8;46:e825 e873. IPMID: 301 1 33791 doi:1 0.1 097/CCM.0000000000003299 and related interventions.

comlbrt and dignity at the end of lil'e. Pharmacologic Patients in the ICU are at risk of developing many hospital Opiates remain as the mainstay therapy acquired conditions. The most common are health care- Multimodal therapy (nonpharmacologic and nonopiate) associated infections. skin and soft tissue pressure injury Consider opiate reduction strateg ies malnutrition, gastrointestinal bleeding, delirium, and weakness Adjunct acetaminophen (see MKSAP 19 Infectious Disease for informaticln on health care associated infections). Protocolized care can improve safety Adjunct low-dose ketamine for postsurgical patients and decrease the incidence ofthese conditions. Adjunct gabapentin, carbamazepine, or pregabalin for nonneuropathic pain Protocols used in the ICU should be evidence based and periodically reviewed to ensure accuracy. For instance, stress Preprocedural pain management with opiate or NSAID ulcer prophylaxis with acid suppression has been standard Sedation Recommendations practice for all patients receiving mechanical ventilation. Use light sedation ratherthan deep sedation in mechanically Randomized trials evaluating acid suppression compared with ventilated patients placebo in patients who are at risk fbund decreased incidence Use sedation protocols of clinically significant bleeding, but no difference in mortality. Nurse-driven protocol There was no difference in the incidence of pneumonia or Daily sedation interruption Clostridioides difficile infection. To this effect, practice guide Favor use of propofol or dexmedetomidine over lines give a weak recommendation to stress ulcer prophylaxis benzodiazepines in those at high risk (i.e., patients with coagulopathy or chronic Use an objective scale to titrate sedation liver disease or who are receiving mechanical ventilation). Use a bispectral index monitor to assess sedation when scales The complexity of disease and interventions in a critically cannot be used (e.g., neuromuscular blockers) ill patient requires a methodical approach to daily care such as Data from Devlin JW, Skrobik Y, G6linas C, et al. C inical practlce quidelines for the the organ system based approach, which allows caregivers to prevention and management of pain, agitation/sedation, delirium, immobility, and review the main disease process, afT'ected organs and systems, sleep disruption in adult patients in the lCU. Crit Care Med. 201 8;46:e825 e873. IPMID: 301 1 33791 doi:1 0.1 097/CCM.0000000000003299 and related interventions. 59