Noninvasive oxygenation and ventilation strategies for viral acute respiratory failure: a comprehensive systematic review and meta-analysis.

Summary

Across 47 studies, high-flow nasal cannula (HFNC), noninvasive mechanical ventilation (NIMV), and CPAP were each associated with lower ICU mortality risk versus invasive mechanical ventilation in viral acute respiratory failure, with exploratory meta-regression reducing heterogeneity to near zero. ICU length of stay was modestly reduced with NIMV and HFNC. Overall certainty by GRADE ranged from very low to moderate.

Key Findings

• HFNC reduced ICU mortality versus IMV (RR 0.54, 95% CI 0.42–0.71).
• NIMV reduced ICU mortality versus IMV (RR 0.70, 95% CI 0.58–0.85).
• CPAP reduced ICU mortality versus IMV (RR 0.80, 95% CI 0.71–0.90).
• ICU length of stay modestly decreased with NIMV (−0.38 days) and HFNC (−0.29 days).
• GRADE certainty ranged from very low to moderate; nosocomial infection and barotrauma data were insufficient.

Clinical Implications

Consider HFNC, NIMV, or CPAP early in viral ARF/ARDS when appropriate expertise and monitoring are available, recognizing evidence certainty is low-to-moderate and patient selection is critical.

Limitations

• Overall GRADE certainty very low to moderate; many comparisons are observational and prone to confounding by indication.
• Insufficient data on nosocomial infection and barotrauma; variable definitions and protocols across studies.

Future Directions

Prospective randomized trials comparing HFNC/CPAP/NIMV strategies, standardized protocols, and safety outcomes (infection, barotrauma) are needed, including resource-limited settings.