Does apneic oxygenation prevent desaturation during emergency airway management? A systematic review and meta-analysis

Purpose Apneic oxygenation (AO) via nasal cannulae is a potential method for preventing oxygen desaturation during emergency intubations. The purpose of this systematic review was to determine the effectiveness of AO in preventing oxygen desaturation during emergency intubations. Source Three electronic databases (MEDLINE, EMBASE and CINAHL) were systematically searched to identify studies that examined the prevention of oxygen desaturation using AO via nasal cannulae. Our primary outcome was the incidence of oxygen desaturation as defined by each individual study; we secondarily assessed the incidence of severe oxygen desaturation (SpO2\ 80%). A meta-analysis of studies reporting data on oxygen desaturation as defined by each study and in patients with severe desaturation was performed to generate a pooled effect estimate. Principal findings A total of 544 studies were screened, of which ten studies (2,322 patients) met all eligibility criteria. Compared with no AO, the use of AO was associated with a reduction of oxygen desaturation (relative risk [ RR], 0.76; 95% confidence interval [CI], 0.61 to 0.95; P = 0.02), but not associated with a reduction in severe oxygen desaturation (RR, 0.65; 95% CI, 0.38 to 1.11; P = 0.12). Nevertheless, significant heterogeneity in patient factors, interventions, and oxygen desaturation definitions was present between studies. Conclusion Our findings suggest that AO via nasal cannulae is associated with a lower risk of oxygen desaturation during emergency intubations. Nevertheless, as there was significant heterogeneity between the studies, more high-quality trials are required to determine which patients may benefit from AO in emergency intubations.