Neuromuscular blocking agents for tracheal intubation of critically ill adults: a systematic review and meta-analysis

Emergency tracheal intubation in critically ill adults is associated with a high risk of peri-intubation adverse events, making first-attempt success a key safety target.

This study aimed to evaluate whether the use of neuromuscular blocking agents (NMBAs) improves the proportion of first-attempt success and reduces adverse events during emergent intubations outside the operating room.

This was a systematic review and meta-analysis of randomized clinical trials or nonrandomized studies comparing sedative-hypnotic plus NMBA versus sedative-hypnotic alone in critically ill adults undergoing emergency endotracheal intubation in nonoperative settings. Animal, cadaveric, manikin/simulation, and pediatric studies were excluded. Articles were screened on 21 August 2025, in Ovid MEDLINE, Ovid Embase, Ovid Cochrane Central Register of Controlled Trials, and the Web of Science Core Collection.

Of 4736 screened citations, 13 studies (8 cohort; 5 before-after studies) were included in the quantitative analysis, with 14 072 participants. NMBA use was associated with higher first-attempt success, which ranged from 69 to 92% (pooled odds ratio, 2.72; 95% onfidence interval: 1.42-5.21; low-certainty evidence). Secondary outcomes related to adverse events were rated as very low certainty due to sparse data, inconsistent reporting, and serious imprecision.

NMBA use during emergency intubation was associated with improved first-attempt success, although the certainty of evidence was low.