Abstract / Summary
The ventilatory ratio (VR) has been proposed as a simple and accessible index to estimate ventilatory inefficiency and physiological dead space in critically ill patients with acute respiratory distress syndrome (ARDS). However, its association with mortality remains controversial, partly due to the methodological heterogeneity of the published studies. A systematic review and Bayesian random-effects meta-analysis were conducted to assess the association between VR and mortality in patients with ARDS. Observational studies reporting crude or adjusted odds ratios (OR) that analysed the association between VR and mortality were included. The search was performed in PubMed, Embase, Scopus, Cochrane, and LILACS databases up to April 2025. Bayesian model, subgroup analyses, meta-regression, and sensitivity analyses were applied. Publication bias was assessed using a funnel plot and Egger's test. Risk of bias was evaluated using the Quality In Prognosis Studies (QUIPS) tool, and the certainty of evidence was assessed using the GRADE approach. The protocol was registered in PROSPERO (CRD42024538654). A total of 23 studies were identified, of which 17 were included in the systematic review and meta-analysis of observational studies. The pooled OR for the association between VR and mortality was 1.55 (95% credible interval: 1.27-1.96), with moderate-to-high heterogeneity (τ = 0.41, I2 = 71.9%). Sensitivity and meta-regression analyses confirmed the robustness of the findings across different model specifications and study characteristics. Risk of bias was rated as moderate in 3 studies and low in 20, according to the QUIPS tool, and the overall certainty of the evidence was rated as low using the GRADE approach. Higher VR values were associated with increased mortality risk in patients with ARDS. However, moderate-to-high heterogeneity across studies indicates that these findings should be interpreted cautiously. VR may represent a complementary prognostic marker, but prospective studies are needed to validate its performance and determine its incremental value over established indices such as PaO2/FiO2.
Primary Source
Respiratory medicine
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