Fig. 1From: Managing the Physiologically Difficult Airway in Critically Ill AdultsEfficacy of high-flow nasal oxygen for apneic oxygenation relative to the severity of respiratory failure. Relative risk indicates reduction in the incidence of severe hypoxemia, defined as SpO2ā<ā80%. (Reproduced from [36] under the Creative Commons Attribution 4.0 International License)Back to article page