LAUSR

Purpose: To evaluate which respiratory support method for critically ill patients undergoing endotracheal intubation (ETI) is associated with less desaturation. Methods: We searched PubMed, Cochrane Library, Scopus and CINAHL databases. We included randomized (RCT) and non‐randomized (non‐RCT) studies investigating any method of respiratory support before/during ETI compared to a reference control. Results: Apneic oxygenation (ApOx) was the most commonly investigated respiratory support technique for critically ill patients undergoing intubation (4 RCTs, 358 patients). Three of these studies investigated high‐flow nasal cannula (HFNC) for ApOx while standard nasal cannula was used in one. Globally, ApOx was associated with higher minimum SpO2 value compared to those receiving ETI without ApOx (mean difference 2.31%, 95% CI 0.42 to 4.20, p = 0.02, I2 = 0%) but there were not significant differences between groups in severe hypoxemia and intubation related – complications. Concerning other techniques, noninvasive ventilation (NIV) was compared to bag‐valve mask in only one RCT and it reduced the degree of desaturation. Conclusions: ApOx was significantly associated with higher minimum SpO2 registered during the intubation procedure. Further studies are needed to increase the number of included patients and demonstrate the benefit of ApOx and of other respiratory support methods (e.g. NIV, HFNC). HIGHLIGHTSApneic oxygenation is the most studied respiratory support for critically ill patients undergoing endotracheal intubationApneic oxygenation is associated with a reduced risk of hypoxemiaOther less studied methods of respiratory support (e.g. noninvasive ventilation) should be better investigatedFurther studies are needed to increase the number of included patients