EmergeNcy Department Apneic Oxygenation Versus Usual Care During Rapid Sequence Intubation : A Randomized Controlled Trial (The ENDAO Trial)

Hypoxia may occur during rapid sequence intubation (RSI) of emergency department patients (1-4). This condition may increase the risk of the patient suffering a cardiac arrest secondary to securing the airway. A part of RSI is pre-oxygenation, which is defined as placing the patient on 100% fraction of inspired O2 for 3 minutes prior to administering the induction agents (i.e. sedative and neuromuscular blocker) in order to increase the amount of oxygen present in the functional residual capacity of the patients lungs to prolong oxygen saturating during the apneic period of endotracheal intubation (5-9). In the last decade, physicians have developed a process known as diffuse apneic oxygenation (DAO) in order to mitigate the risk of oxygen desaturation during this apneic period. The process entails leaving the patient on high flow nasal cannula (HFNC) oxygen during the act of visualizing the vocal cords and placing the endotracheal tube. Over the years the practice has started to become more common in emergency departments, operating rooms and ICU's all over the world. Recently, a randomized controlled trial (called The FELLOW Trial) of this practice demonstrated no difference in desaturation rates between those patients that received DAO and those that did not (usual practice) in patients in the ICU (10). Some have commented that the findings of this study cannot be applied to emergency department patients, and so evidence is lacking in regards to this population.

Purpose of the study:

Although studies have started to investigate the efficacy of DAO in preventing desaturation during RSI, evidence is still lacking in the emergency department patient population. The primary question being asked is: does diffuse apneic oxygenation increase the average lowest arterial oxygen saturation during rapid sequence intubation when compared to usual care? Secondary question being asked is: does diffuse apneic oxygenation decrease the incidence of desaturation in general, as well as hypoxemia and severe hypoxemia? The third question being asked is: does diffuse apneic oxygenation increase the time to desaturation?