# Effectiveness of noninvasive ventilation for preoxygenation in emergency intubation: a systematic review and meta-analysis

## TL;DR

This study compares noninvasive ventilation and bag-valve-mask ventilation for preoxygenation during emergency intubation, finding that noninvasive ventilation reduces hypoxemia risk.

## Contribution

The study provides new evidence that noninvasive ventilation is more effective than bag-valve-mask for preoxygenation in reducing hypoxemia during emergency intubation.

## Key findings

- Noninvasive ventilation significantly reduces hypoxemia during intubation compared to bag-valve-mask.
- No significant difference in all-cause mortality or regurgitation rates between the groups.
- Results were consistent across frequentist and Bayesian statistical models.

## Abstract

To evaluate the impact of noninvasive ventilation versus bag-valve-mask ventilation preoxygenation on safety and efficacy outcomes.

PubMed, Embase, and Cochrane databases were searched for randomized controlled trials that compared preoxygenation using noninvasive ventilation and bag-valve-mask ventilation. The reported outcomes were all-cause mortality; hypoxemia during intubation; and regurgitation. We perform frequentist and Bayesian analysis. Heterogeneity was examined with I2 statistics. Statistical analysis was done using RStudio and Review Manager.

We included 3 randomized controlled trials with 1,555 patients, of whom 771 (49.6%) received preoxygenation with noninvasive ventilation (intervention group). Hypoxemia during intubation was significantly lower in the noninvasive ventilation compared to the bag-valve-mask ventilation group in frequentist with a pooled log RR of −0.94 (log RR −0.94; 95%CI −1.61 − −0.28) and Bayesian pooled log risk ratio of −0.32 (log RR −0.32; 95% credible interval −0.91 − 0.40). Regurgitation was a safety outcome that did not present a difference between the groups in the frequentist or Bayesian models, with log RR −0.50 (log RR −0.50; 95% credible interval −2.09 − 1.01). There was no significant difference between groups in all-cause mortality and other secondary outcomes.

Preoxygenation with noninvasive ventilation significantly reduces the risk of hypoxemia during emergency intubation compared to bag-valve-mask ventilation. However, there were no significant differences in all-cause mortality or regurgitation rates.