Noninvasive ventilation versus oxygen mask for preoxygenation before emergency tracheal intubation in critically ill...

To compare the effectiveness and safety of noninvasive ventilation (NIV) versus standard oxygen mask for preoxygenation before emergency intubation in critically ill adults.

Systematic review and meta-analysis of randomized clinical trials following PRISMA 2020. Protocol registered in PROSPERO (CRD420251028685). Risk ratios (RR) were calculated using random-effects models with HKSJ adjustment. Certainty assessed using GRADE.

Intensive care units and emergency departments. Only in-hospital settings were included.

1619 critically ill adults requiring emergency intubation from four RCTs (802 NIV, 817 standard mask). Mean age ranged from 55 to 65 years across trials; 79% enrolled in ICUs, 21% in EDs.

Preoxygenation with NIV (CPAP or bilevel positive airway pressure) versus standard passive facemask oxygenation without positive pressure.

Primary outcome: peri-intubation hypoxemia (SpO₂ < 80%). Safety outcome: aspiration or regurgitation.

Peri-intubation hypoxemia occurred in 63/802 (7.9%) with NIV versus 144/817 (17.6%) with mask (RR 0.39; 95% CI 0.14-1.04; p = 0.08; I² = 55%). The point estimate favored NIV, but the confidence interval crossed unity under the HKSJ-adjusted model. Three of four trials individually showed significant reductions. Aspiration was infrequent (1.0% vs 1.7%; p = 0.31). Certainty was moderate for hypoxemia and low for safety.

Preoxygenation with NIV did not significantly reduce peri-intubation hypoxemia compared with a standard oxygen mask under the HKSJ-adjusted model. Nonetheless, the pooled point estimate favored NIV and three of the four trials showed significant reductions, suggesting a possible benefit that did not reach statistical significance. No increases in adverse events were observed. The decision to use NIV should be individualized according to clinical context, patient profile, and team experience.