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Changing clinical practice to maximize success of ICU airway management
Airway management is a complex process that, if not performed in a proper and timely manner, may result in significant morbidity or mortality. The risk of intubation failure and associated adverse events is higher in critically ill patients due to differences in patient condition, environment, and practitioner experience. Even when controlling for provider experience, intubating conditions are worse and success rates are lower in the ICU compared with the controlled environment of the operating room (Taboada, et al. Anesthesiology. 2018;129[2]:321). Furthermore, the risk of injury and adverse events increases with the number of intubation attempts during an emergency (Sakles JC, et al. Acad Emerg Med. 2013;20[1]:71). Unfortunately, the paucity of high-grade evidence leads practitioners to rely on practice patterns developed during training and predicated on common sense airway management principles. The difficulty in evaluating airway management in the critically ill lies in the multi-step and complex nature of the process, including the pre-intubation, intubation, and post-intubation activities (Fig 1). Several recent publications have the potential to change airway management practice in the ICU. We will address the latest information on preoxygenation, use of neuromuscular blockade (NMB), and checklists in this setting.
Preoxygenation: Overrated?
Rapid-sequence intubation (RSI) is a technique intended to minimize the time from induction to intubation and reduce the risk of aspiration by primarily avoiding ventilation. The avoidance of bag-mask ventilation during this apneic period is common, due to concerns that positive pressure can produce gastric insufflation and regurgitation that may lead to aspiration. To attenuate the risk for critical desaturation, preoxygenation is classically provided prior to induction of anesthesia in the operative procedural areas. Although the benefit can be seen in patients undergoing elective intubation, critically ill patients often have difficulty in significantly raising the blood oxygen content despite preoxygenation with 100% oxygen delivered via face mask. As a result, the oxygen saturation can drop precipitously during the process of ICU intubation, especially if multiple or prolonged intubation attempts are required. These factors all contribute to the risk of hypoxemia and cardiac arrest during ICU intubations (De Jong A, et al. Crit Care Med. 2018;46[4]:532), which has led to the debate about the avoidance of ventilation during RSI in the critically ill. Recently, Casey and colleagues (Casey JD, et al. N Engl J Med. 2019;380[9]:811) evaluated the use of bag-mask ventilation (BMV) during RSI. In this ICU study, intubations were randomized to either include BMV or no ventilation after induction. The results suggested that the frequency of critical desaturation was lower in the patients receiving BMV after induction without a concomitant increase in frequency of aspiration. Although not powered to evaluate the difference in the incidence of aspiration, this study supports the use of BMV during the apneic phase of intubation, thereby decreasing the risk for critical desaturation.
Neuromuscular blockade: Yes or no?
Awake intubation, with or without sedation, is often employed for managing the airway in high-risk patients. This technique allows the patient to maintain spontaneous ventilation in the event of repeated intubation attempts and has a lower hypotension risk. However, many critically ill patients cannot be managed in this manner due to lack of patient cooperation, emergent airway management requirements, or practitioner inexperience with this technique. As a result, many of these patients will require an induction agent, and concomitant administration of a neuromuscular blocking agent (NMB) to optimize intubating conditions. However, the avoidance of NMBs in emergent airway scenarios was not uncommon among attending physicians and trainees (Schmidt UH, et al. Anesthesiology. 2008;109[6]:973). The American College of Chest Physicians (CHEST) Difficult Airway Course faculty also recommended to not use NMB because of the high risk of failure to ventilate/oxygenate. Without NMB, the patient might be allowed to recover to spontaneous ventilation. This approach is taken in the American Society of Anesthesiologists Practice Guidelines for the Management of the Difficult Airway but is not necessarily applicable to the critically ill patient (Apfelbaum JL, et al. Anesthesiology. 2013;118[2]:251-70). In the event of “can’t intubate, can’t oxygenate” (CICO), the critically ill patient in extremis may not tolerate an attempt to return to spontaneous ventilation because spontaneous ventilation may have been initially inadequate.
In 2010, Jaber and colleagues demonstrated a lower incidence of hypoxemia and severe hemodynamic collapse with the implementation of an intubation bundle that included the use of NMBs for all rapid-sequence inductions (Jaber S, et al. Int Care Med. 2010;36:248). The safety of using paralytics in critically ill patients was later investigated by Wilcox and colleagues in a prospective, observational study that suggested a decrease in the incidence of hypoxemia and complications when employing NMB (Wilcox SR, et al. Crit Care Med. 2012;40[6]:1808). Although Wilcox et al.’s study was hypothesis-generating by the nature of its design, it was consistent with both Jaber’s findings and a more recent observational study performed by Moser et al (Mosier JM, et al. Ann Am Thorac Soc. 2015;12[5]:734). Furthermore, there is no evidence that NMBs worsen bag mask ventilation in the critically ill patient. NMBs in addition to induction agents might be associated with optimal intubating conditions, reduced complications, and allow for placement of a supraglottic airway device or surgical airway in the event of a CICO (Higgs A, et al. Br J Anaesth. 2018;120[2]:323).
Checking the checklists
Checklists are another intervention with the potential to improve outcomes or reduce adverse events. Airway management is often a complex process with significant opportunities for failure. Therefore, having reminders or checklists available to the provider may encourage the use of best practices. Jaber demonstrated that a straightforward, 10-point intubation bundle reduced the incidence of severe complications associated with emergent intubation in the ICU. In the 4th National Audit Project of the Royal College of Anaesthetists and Difficult Airway Society, the use of checklists was recommended as a method to reduce adverse events and increase successful airway management (Cook TM, et al. Br J Anaesth. 2011;106[5]:632). In fact, several mnemonics have been developed to aid the practitioner, including the ‘7 Ps’ in the Manual of Emergency Airway Management (Walls RM, et al. Manual of Emergency Airway Management. 2012) and APPROACH from the CHEST Airway Management Training Team. More recently, Janz and colleagues developed and employed a checklist in a multicenter study and compared it with usual practice (Janz DR, et al. Chest. 2018;153[4]:816). Although the checklist was associated with improved provider compliance with airway assessment, preparation, and verbalization of a plan, it did not go far enough to include the known interventions for optimizing preoxygenation and hemodynamic stability. Two elements that might be included in a checklist include fluids and vasopressors administration during the pre-intubation and post-intubation period, and preoxygenation with noninvasive ventilation. The former is associated with a lower incidence of hypotension, while the latter may reduce the incidence of severe hypoxemia in ICU intubations (Baillard C, et al. Am J Respir Crit Care Med. 2006;174[2]:171).
Keeping apprised of evidence and adjusting practice are crucial to the competent clinician engaging in airway management, as they minimize the risk of harm while maximizing the benefit to the patient. However, the methods to achieve these goals are not always intuitive. Definitive high-level evidence is sparse. The use of neuromuscular blockade and BMV after induction has historically been controversial, but more recent evidence is favoring these approaches for RSI. The use of checklists or guidelines may ensure that the necessary safety steps are followed, especially at institutions that may not have experts in airway management. Over time, the hope is that many of our traditional practices are either supported by quality evidence or better techniques evolve.
Dr. Tokarczyk is with the Department of Anesthesia, NorthShore University HealthSystem; and Clinical Assistant Professor, University of Chicago, Pritzker School of Medicine. Dr. Greenberg is Editor-in-Chief, Anesthesia Patient Safety Foundation (APSF) Newsletter; Vice Chairperson, Education, Department of Anesthesiology; Director of Critical Care Services, Evanston Hospital; NorthShore University HealthSystem; and Clinical Professor, Department of Anesthesiology Critical Care, University of Chicago, Pritzker School of Medicine.
Airway management is a complex process that, if not performed in a proper and timely manner, may result in significant morbidity or mortality. The risk of intubation failure and associated adverse events is higher in critically ill patients due to differences in patient condition, environment, and practitioner experience. Even when controlling for provider experience, intubating conditions are worse and success rates are lower in the ICU compared with the controlled environment of the operating room (Taboada, et al. Anesthesiology. 2018;129[2]:321). Furthermore, the risk of injury and adverse events increases with the number of intubation attempts during an emergency (Sakles JC, et al. Acad Emerg Med. 2013;20[1]:71). Unfortunately, the paucity of high-grade evidence leads practitioners to rely on practice patterns developed during training and predicated on common sense airway management principles. The difficulty in evaluating airway management in the critically ill lies in the multi-step and complex nature of the process, including the pre-intubation, intubation, and post-intubation activities (Fig 1). Several recent publications have the potential to change airway management practice in the ICU. We will address the latest information on preoxygenation, use of neuromuscular blockade (NMB), and checklists in this setting.
Preoxygenation: Overrated?
Rapid-sequence intubation (RSI) is a technique intended to minimize the time from induction to intubation and reduce the risk of aspiration by primarily avoiding ventilation. The avoidance of bag-mask ventilation during this apneic period is common, due to concerns that positive pressure can produce gastric insufflation and regurgitation that may lead to aspiration. To attenuate the risk for critical desaturation, preoxygenation is classically provided prior to induction of anesthesia in the operative procedural areas. Although the benefit can be seen in patients undergoing elective intubation, critically ill patients often have difficulty in significantly raising the blood oxygen content despite preoxygenation with 100% oxygen delivered via face mask. As a result, the oxygen saturation can drop precipitously during the process of ICU intubation, especially if multiple or prolonged intubation attempts are required. These factors all contribute to the risk of hypoxemia and cardiac arrest during ICU intubations (De Jong A, et al. Crit Care Med. 2018;46[4]:532), which has led to the debate about the avoidance of ventilation during RSI in the critically ill. Recently, Casey and colleagues (Casey JD, et al. N Engl J Med. 2019;380[9]:811) evaluated the use of bag-mask ventilation (BMV) during RSI. In this ICU study, intubations were randomized to either include BMV or no ventilation after induction. The results suggested that the frequency of critical desaturation was lower in the patients receiving BMV after induction without a concomitant increase in frequency of aspiration. Although not powered to evaluate the difference in the incidence of aspiration, this study supports the use of BMV during the apneic phase of intubation, thereby decreasing the risk for critical desaturation.
Neuromuscular blockade: Yes or no?
Awake intubation, with or without sedation, is often employed for managing the airway in high-risk patients. This technique allows the patient to maintain spontaneous ventilation in the event of repeated intubation attempts and has a lower hypotension risk. However, many critically ill patients cannot be managed in this manner due to lack of patient cooperation, emergent airway management requirements, or practitioner inexperience with this technique. As a result, many of these patients will require an induction agent, and concomitant administration of a neuromuscular blocking agent (NMB) to optimize intubating conditions. However, the avoidance of NMBs in emergent airway scenarios was not uncommon among attending physicians and trainees (Schmidt UH, et al. Anesthesiology. 2008;109[6]:973). The American College of Chest Physicians (CHEST) Difficult Airway Course faculty also recommended to not use NMB because of the high risk of failure to ventilate/oxygenate. Without NMB, the patient might be allowed to recover to spontaneous ventilation. This approach is taken in the American Society of Anesthesiologists Practice Guidelines for the Management of the Difficult Airway but is not necessarily applicable to the critically ill patient (Apfelbaum JL, et al. Anesthesiology. 2013;118[2]:251-70). In the event of “can’t intubate, can’t oxygenate” (CICO), the critically ill patient in extremis may not tolerate an attempt to return to spontaneous ventilation because spontaneous ventilation may have been initially inadequate.
In 2010, Jaber and colleagues demonstrated a lower incidence of hypoxemia and severe hemodynamic collapse with the implementation of an intubation bundle that included the use of NMBs for all rapid-sequence inductions (Jaber S, et al. Int Care Med. 2010;36:248). The safety of using paralytics in critically ill patients was later investigated by Wilcox and colleagues in a prospective, observational study that suggested a decrease in the incidence of hypoxemia and complications when employing NMB (Wilcox SR, et al. Crit Care Med. 2012;40[6]:1808). Although Wilcox et al.’s study was hypothesis-generating by the nature of its design, it was consistent with both Jaber’s findings and a more recent observational study performed by Moser et al (Mosier JM, et al. Ann Am Thorac Soc. 2015;12[5]:734). Furthermore, there is no evidence that NMBs worsen bag mask ventilation in the critically ill patient. NMBs in addition to induction agents might be associated with optimal intubating conditions, reduced complications, and allow for placement of a supraglottic airway device or surgical airway in the event of a CICO (Higgs A, et al. Br J Anaesth. 2018;120[2]:323).
Checking the checklists
Checklists are another intervention with the potential to improve outcomes or reduce adverse events. Airway management is often a complex process with significant opportunities for failure. Therefore, having reminders or checklists available to the provider may encourage the use of best practices. Jaber demonstrated that a straightforward, 10-point intubation bundle reduced the incidence of severe complications associated with emergent intubation in the ICU. In the 4th National Audit Project of the Royal College of Anaesthetists and Difficult Airway Society, the use of checklists was recommended as a method to reduce adverse events and increase successful airway management (Cook TM, et al. Br J Anaesth. 2011;106[5]:632). In fact, several mnemonics have been developed to aid the practitioner, including the ‘7 Ps’ in the Manual of Emergency Airway Management (Walls RM, et al. Manual of Emergency Airway Management. 2012) and APPROACH from the CHEST Airway Management Training Team. More recently, Janz and colleagues developed and employed a checklist in a multicenter study and compared it with usual practice (Janz DR, et al. Chest. 2018;153[4]:816). Although the checklist was associated with improved provider compliance with airway assessment, preparation, and verbalization of a plan, it did not go far enough to include the known interventions for optimizing preoxygenation and hemodynamic stability. Two elements that might be included in a checklist include fluids and vasopressors administration during the pre-intubation and post-intubation period, and preoxygenation with noninvasive ventilation. The former is associated with a lower incidence of hypotension, while the latter may reduce the incidence of severe hypoxemia in ICU intubations (Baillard C, et al. Am J Respir Crit Care Med. 2006;174[2]:171).
Keeping apprised of evidence and adjusting practice are crucial to the competent clinician engaging in airway management, as they minimize the risk of harm while maximizing the benefit to the patient. However, the methods to achieve these goals are not always intuitive. Definitive high-level evidence is sparse. The use of neuromuscular blockade and BMV after induction has historically been controversial, but more recent evidence is favoring these approaches for RSI. The use of checklists or guidelines may ensure that the necessary safety steps are followed, especially at institutions that may not have experts in airway management. Over time, the hope is that many of our traditional practices are either supported by quality evidence or better techniques evolve.
Dr. Tokarczyk is with the Department of Anesthesia, NorthShore University HealthSystem; and Clinical Assistant Professor, University of Chicago, Pritzker School of Medicine. Dr. Greenberg is Editor-in-Chief, Anesthesia Patient Safety Foundation (APSF) Newsletter; Vice Chairperson, Education, Department of Anesthesiology; Director of Critical Care Services, Evanston Hospital; NorthShore University HealthSystem; and Clinical Professor, Department of Anesthesiology Critical Care, University of Chicago, Pritzker School of Medicine.
Airway management is a complex process that, if not performed in a proper and timely manner, may result in significant morbidity or mortality. The risk of intubation failure and associated adverse events is higher in critically ill patients due to differences in patient condition, environment, and practitioner experience. Even when controlling for provider experience, intubating conditions are worse and success rates are lower in the ICU compared with the controlled environment of the operating room (Taboada, et al. Anesthesiology. 2018;129[2]:321). Furthermore, the risk of injury and adverse events increases with the number of intubation attempts during an emergency (Sakles JC, et al. Acad Emerg Med. 2013;20[1]:71). Unfortunately, the paucity of high-grade evidence leads practitioners to rely on practice patterns developed during training and predicated on common sense airway management principles. The difficulty in evaluating airway management in the critically ill lies in the multi-step and complex nature of the process, including the pre-intubation, intubation, and post-intubation activities (Fig 1). Several recent publications have the potential to change airway management practice in the ICU. We will address the latest information on preoxygenation, use of neuromuscular blockade (NMB), and checklists in this setting.
Preoxygenation: Overrated?
Rapid-sequence intubation (RSI) is a technique intended to minimize the time from induction to intubation and reduce the risk of aspiration by primarily avoiding ventilation. The avoidance of bag-mask ventilation during this apneic period is common, due to concerns that positive pressure can produce gastric insufflation and regurgitation that may lead to aspiration. To attenuate the risk for critical desaturation, preoxygenation is classically provided prior to induction of anesthesia in the operative procedural areas. Although the benefit can be seen in patients undergoing elective intubation, critically ill patients often have difficulty in significantly raising the blood oxygen content despite preoxygenation with 100% oxygen delivered via face mask. As a result, the oxygen saturation can drop precipitously during the process of ICU intubation, especially if multiple or prolonged intubation attempts are required. These factors all contribute to the risk of hypoxemia and cardiac arrest during ICU intubations (De Jong A, et al. Crit Care Med. 2018;46[4]:532), which has led to the debate about the avoidance of ventilation during RSI in the critically ill. Recently, Casey and colleagues (Casey JD, et al. N Engl J Med. 2019;380[9]:811) evaluated the use of bag-mask ventilation (BMV) during RSI. In this ICU study, intubations were randomized to either include BMV or no ventilation after induction. The results suggested that the frequency of critical desaturation was lower in the patients receiving BMV after induction without a concomitant increase in frequency of aspiration. Although not powered to evaluate the difference in the incidence of aspiration, this study supports the use of BMV during the apneic phase of intubation, thereby decreasing the risk for critical desaturation.
Neuromuscular blockade: Yes or no?
Awake intubation, with or without sedation, is often employed for managing the airway in high-risk patients. This technique allows the patient to maintain spontaneous ventilation in the event of repeated intubation attempts and has a lower hypotension risk. However, many critically ill patients cannot be managed in this manner due to lack of patient cooperation, emergent airway management requirements, or practitioner inexperience with this technique. As a result, many of these patients will require an induction agent, and concomitant administration of a neuromuscular blocking agent (NMB) to optimize intubating conditions. However, the avoidance of NMBs in emergent airway scenarios was not uncommon among attending physicians and trainees (Schmidt UH, et al. Anesthesiology. 2008;109[6]:973). The American College of Chest Physicians (CHEST) Difficult Airway Course faculty also recommended to not use NMB because of the high risk of failure to ventilate/oxygenate. Without NMB, the patient might be allowed to recover to spontaneous ventilation. This approach is taken in the American Society of Anesthesiologists Practice Guidelines for the Management of the Difficult Airway but is not necessarily applicable to the critically ill patient (Apfelbaum JL, et al. Anesthesiology. 2013;118[2]:251-70). In the event of “can’t intubate, can’t oxygenate” (CICO), the critically ill patient in extremis may not tolerate an attempt to return to spontaneous ventilation because spontaneous ventilation may have been initially inadequate.
In 2010, Jaber and colleagues demonstrated a lower incidence of hypoxemia and severe hemodynamic collapse with the implementation of an intubation bundle that included the use of NMBs for all rapid-sequence inductions (Jaber S, et al. Int Care Med. 2010;36:248). The safety of using paralytics in critically ill patients was later investigated by Wilcox and colleagues in a prospective, observational study that suggested a decrease in the incidence of hypoxemia and complications when employing NMB (Wilcox SR, et al. Crit Care Med. 2012;40[6]:1808). Although Wilcox et al.’s study was hypothesis-generating by the nature of its design, it was consistent with both Jaber’s findings and a more recent observational study performed by Moser et al (Mosier JM, et al. Ann Am Thorac Soc. 2015;12[5]:734). Furthermore, there is no evidence that NMBs worsen bag mask ventilation in the critically ill patient. NMBs in addition to induction agents might be associated with optimal intubating conditions, reduced complications, and allow for placement of a supraglottic airway device or surgical airway in the event of a CICO (Higgs A, et al. Br J Anaesth. 2018;120[2]:323).
Checking the checklists
Checklists are another intervention with the potential to improve outcomes or reduce adverse events. Airway management is often a complex process with significant opportunities for failure. Therefore, having reminders or checklists available to the provider may encourage the use of best practices. Jaber demonstrated that a straightforward, 10-point intubation bundle reduced the incidence of severe complications associated with emergent intubation in the ICU. In the 4th National Audit Project of the Royal College of Anaesthetists and Difficult Airway Society, the use of checklists was recommended as a method to reduce adverse events and increase successful airway management (Cook TM, et al. Br J Anaesth. 2011;106[5]:632). In fact, several mnemonics have been developed to aid the practitioner, including the ‘7 Ps’ in the Manual of Emergency Airway Management (Walls RM, et al. Manual of Emergency Airway Management. 2012) and APPROACH from the CHEST Airway Management Training Team. More recently, Janz and colleagues developed and employed a checklist in a multicenter study and compared it with usual practice (Janz DR, et al. Chest. 2018;153[4]:816). Although the checklist was associated with improved provider compliance with airway assessment, preparation, and verbalization of a plan, it did not go far enough to include the known interventions for optimizing preoxygenation and hemodynamic stability. Two elements that might be included in a checklist include fluids and vasopressors administration during the pre-intubation and post-intubation period, and preoxygenation with noninvasive ventilation. The former is associated with a lower incidence of hypotension, while the latter may reduce the incidence of severe hypoxemia in ICU intubations (Baillard C, et al. Am J Respir Crit Care Med. 2006;174[2]:171).
Keeping apprised of evidence and adjusting practice are crucial to the competent clinician engaging in airway management, as they minimize the risk of harm while maximizing the benefit to the patient. However, the methods to achieve these goals are not always intuitive. Definitive high-level evidence is sparse. The use of neuromuscular blockade and BMV after induction has historically been controversial, but more recent evidence is favoring these approaches for RSI. The use of checklists or guidelines may ensure that the necessary safety steps are followed, especially at institutions that may not have experts in airway management. Over time, the hope is that many of our traditional practices are either supported by quality evidence or better techniques evolve.
Dr. Tokarczyk is with the Department of Anesthesia, NorthShore University HealthSystem; and Clinical Assistant Professor, University of Chicago, Pritzker School of Medicine. Dr. Greenberg is Editor-in-Chief, Anesthesia Patient Safety Foundation (APSF) Newsletter; Vice Chairperson, Education, Department of Anesthesiology; Director of Critical Care Services, Evanston Hospital; NorthShore University HealthSystem; and Clinical Professor, Department of Anesthesiology Critical Care, University of Chicago, Pritzker School of Medicine.