By Alexander Niven, MD

Senior Associate Consultant, Division of Pulmonary/Critical Care Medicine, Mayo Clinic, Rochester, MN

Dr. Niven reports no financial relationships relevant to this field of study.

Airway management is a common, high-risk procedure in the ICU. A decade ago, ICU intubation was associated with complications in more than 50% of cases, including prolonged hypoxemia, hemodynamic instability, cardiac arrest, and death.1 Despite significant improvements in patient safety and outcomes using skilled operators, a systematic approach, and advanced airway tools, more recent publications still report a complication rate in the critically ill that remains unacceptably high. Recent evidence and guidelines help inform best airway practice in the ICU, but challenges and controversies remain.


Airway management in the ICU often is emergent and performed in patients with significant cardiopulmonary disease, hemodynamic instability, and upper airway abnormalities. (See Table 1.) These factors limit deliberate planning and preparation, decrease the time to perform intubation before hypoxemia develops, and reduce glottic visualization during the procedure. The result is a high incidence of difficult airways — defined as clinical factors that complicate ventilation by facemask or intubation by a skilled operator — reported to be 7-10% in this population.2,3

Current studies still report complication rates from ICU intubation of 4.2% to 22%.3-6 Hypoxemia is the most common cause of serious complications, but post-intubation hypotension also has been associated with poor patient outcomes in a large retrospective, multicenter cohort.7 ICU patients also present special management challenges for airway management, such as increased intracranial pressure and active coronary ischemia. A recent large cohort study found 47% of the critically ill patients who suffered airway complications in the Royal College of Anesthetists’ Fourth National Audit Project were obese, and the incidence of difficult intubation in this population was twice as frequent in the ICU than the OR (16.3% vs. 8.2%; P < 0.01).6,8

Multiple international studies also have documented variable staff training, limited availability of airway equipment in the ICU, and communication and teamwork errors as common causes of adverse outcomes during airway management.6,9-11 This has led some to call for anesthesiologists alone to perform intubations in the critically ill, but survey data suggest that training and performance gaps in the management of difficult airways in these patients are common, even within this specialty.12-15


A systematic approach to airway assessment, patient and equipment preparation, and procedure planning clearly has been shown to increase the rate of intubation success. In a two-phase, multicenter, prospective study of 244 intubations, Jaber et al demonstrated that implementation of a protocolized ICU intubation bundle (see Table 2) reduced the incidence of both life-threatening and other complications by 13% and 12%, respectively.4 Implementation of a standardized, team-based approach to airway management, simulation-based airway skills and teamwork training, and a mandatory bedside procedure checklist also have been shown to improve patient safety with tracheal intubation and to reduce the need for emergent surgical airway procedures.16,17


Preoxygenation can be less effective in patients with significant cardiopulmonary disease, leaving little time for an intubation attempt before hypoxemia develops. Apneic oxygenation is the delivery of supplemental oxygen through the nasopharynx without ventilation, and has shown promise in small, nonrandomized trials examining its use in intubation outside the OR. However, in the first prospective, randomized trial to examine this issue, no difference was observed in 150 critically ill medical patients who received either 15 L/min supplemental oxygen by nasal cannula or no additional oxygen during laryngoscopy attempts. Investigators maintained a high rate of compliance with best practices of preoxygenation, patient positioning, and equipment preparation, which may have reduced the potential additional benefit of this intervention. Further, investigators also excluded patients with anticipated difficult airways, a group in whom apneic oxygenation may produce the best outcome during a prolonged intubation attempt and is recommended in current guidelines.18,19

There has been considerable interest in the use of advanced airway tools to increase the success and safety of intubation in the ICU. Videolaryngoscopy (VL), a term used to describe a wide range of intubating devices that employ a video display to provide better glottic visualization, has shown promise in small cohort studies and one randomized, controlled study. However, a recent large, prospective, randomized study comparing standard direct laryngoscopy with videolaryngoscopy in the ICU did not demonstrate a difference in the rate of first attempt success, time to intubation, or complications despite better glottic visualization in the VL group.20 Methodologic differences in this trial compared to prior positive studies included more aggressive use of neuromuscular blockade, the use of the McGrath MAC video laryngoscope instead of the GlideScope, and the exclusion of patients with anticipated difficult airways who were intubated using video or fiber optic techniques.21

Anatomic features continue performing poorly as a tool for identifying patients with a difficult airway, with the MACOCHA score the best validated tool to identify at-risk patients in the ICU.22,23 In light of this, a practical and informed approach to the unanticipated difficult airway is crucial for critical care providers. The Difficult Airway Society (DAS) published new guidelines for the management of an unanticipated difficult airway in 2015, which are summarized in Table 3.19

The guidelines emphasize the importance of adequate sedation and neuromuscular blockade to maximize glottic visualization and first pass success, preoxygenation to maximize time for intubation, and treatment at a facility with videolaryngoscopy in situations in which a difficult airway is anticipated. A gum elastic bougie also is encouraged in situations of incomplete glottic visualization, supported by its major role as a primary rescue device in prior studies.3

If initial intubation attempts are not successful, the DAS encourages early use of a second generation extraglottic airway (EGA) to preserve oxygenation, with best current evidence supporting the i-gel (Intersurgical, Wokingham, UK), the ProSeal LMA (PLMA; Teleflex Medical Europe Ltd, Athlone, Ireland), and the LMA Supreme (SLMA; Teleflex Medical Ltd). Limiting the number of EGA placement attempts to three minimizes airway trauma without reducing overall success rate. Successful placement ensures adequate oxygenation and ventilation and provides time to plan for the next step to manage the failed airway, which in the critically ill patient is most likely fiber optic intubation through the EGA or a surgical airway. For patients in whom EGA placement and repeat bag valve mask ventilation is not successful, the DAS recommends early scalpel cricothyroidotomy with placement of a wide-bore cuffed tube over a bougie as the preferred surgical airway approach.


Some organizations have developed Difficult Airway Response Teams (DARTs) as a solution to the challenges of standardizing equipment, approach, and training in airway management in large institutions with multiple ICUs. Although DARTs offer the opportunity to deploy a multidisciplinary, well-trained airway team with standardized equipment to the bedside of an anticipated or identified difficult airway, criteria, timing, and coordination of team activation and involvement must be carefully delineated based on the volume of procedures, resources, and capabilities within the various hospital areas in which staff perform intubations. Key factors that have warranted DART activation in one institution’s experience include a history of a difficult airway, cervical spine injury or fixation, oropharyngeal and/or supraglottic angioedema, and airway bleeding.24


The rapid evolution of airway devices and increased emphasis on sedation and neuromuscular blockade in recent airway guidelines present challenges and some controversies for many practicing intensivists. Many modern airway devices have been developed for airway management in the OR, and recent literature only further emphasizes that their appropriate roles in an airway management algorithm for the critically ill must be defined better. Although full induction doses of agents, such as propofol, that are recommended in current DAS guidelines have been shown to be safe and effective in the critically ill with preemptive vasopressor administration,24 many intensivists are less than comfortable with full-dose induction agents, neuromuscular blockers, and rapid sequence intubation protocols in critically ill patients. When and in which patients this strategy should be used also could merit further refinement.


Airway management remains a high-risk procedure in the ICU. Safety and success rates have significantly improved over the past decade with implementation of a systematic approach that emphasizes preoxygenation, appropriate patient positioning, pre-induction volume loading and vasopressor administration, teamwork and communication between skilled airway operators, and multidisciplinary teams assisting them. Recent guidelines favor early and aggressive neuromuscular blockade to maximize the chances of first-pass intubation success, along with early use of an EGA and, when necessary, scalpel cricothyroidotomy to reestablish adequate oxygenation. How best to apply these guidelines and other advanced airway tools in the critically ill still requires further study, along with an examination of the initial and maintenance training and procedural volume required for an intensivist to maintain competence in this procedure.


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Table 1: Challenges, Potential Solutions in ICU Airway Management





Emergent situation, increased
difficult airway incidence

Less time for airway
assessment, planning

Multiple, skilled operators*

Cardiopulmonary disease

Rapid desaturation

Deliberate preoxygenation*

Apneic oxygenation

Early extraglottic airway*

Hemodynamic instability

Induction drug limits

Increased mortality

Volume loading*

Early vasopressor use*

Upper airway edema, secretions, loss of tone

Decreased glottic visualization

Advanced airway tools


Decreased glottic visualization, rapid desaturation



Staffing, Training

Low volume, variable training

Less prepared to manage high risk airways

Limit procedure to experts

Improve training programs


Teamwork, communication

Errors, worse outcomes

Dedicated airway teams

Teamwork training*



Rapid development of new airway devices

Variables availability, expertise in ICU

Standardized airway cart

Validate best tools in ICU patients

*Indicates solution is supported by current published best evidence

Table 2: An ICU Intubation Bundle Improves Patient Outcomes


1. Presence of two operators

2. Fluid loading in absence of cardiogenic pulmonary edema

3. Preparation of long-term sedation

4. Preoxygenation for 3 minutes with non-invasive positive pressure ventilation in case of acute respiratory failure

During intubation

5. Rapid sequence induction: etomidate 0.2-0.3 mg/kg or ketamine 1.5-3 mg/kg combined with succinylcholine
1-1.5 mg/kg in absence of contraindications

6. Sellick maneuver


7. Immediate confirmation of tube placement by capnography

8. Norepinephrine if diastolic blood pressure remains
< 35 mmHg

9. Initiate long-term sedation

10. Initial “protective ventilation:” tidal volume 6-8 mL/kg of ideal body weight for a plateau pressure < 30 cm H2O

SOURCE: Jaber S, Jung B, Corne P, et al. An intervention to decrease complications related to endotracheal intubation
in the intensive care unit: A prospective, multiple-center study. Intensive Care Med 2010;36:248-255.

Table 3: ICU Adaptation of Difficult Airway Society Guidelines

Airway Management Steps

Key Points

Plan A: Facemask ventilation, tracheal intubation

  • Preoxygenation for all patients
  • Head-up positioning, ramping
  • Apneic oxygenation in high-risk patients
  • Neuromuscular blockade
  • Consider videolaryngoscopy
  • Maximum of three laryngoscopy attempts (plus one if skilled
  • Remove cricoid pressure if
    intubation difficult

Plan B: Insert
extraglottic airway device (EGA)

  • Early use to preserve oxygenation
  • Second-generation EGAs
  • Maximum of three EGA insertion attempts
  • Remove cricoid pressure
  • Use fiberoptic guidance for
    intubation through EGA

Plan C: Surgical airway

  • Scalpel cricothyroidotomy
  • Bougie assisted placement of 6.0 mm cuffed endotracheal tube
  • High-pressure oxygenation through narrow-bore cannula discouraged
  • Regular training for airway