Secondary analysis of hospital mortality risks associated with the lateral-Trendelenburg vs. semirecumbent body position - The Gravity-VAP Trial

Background: We recently completed a randomized clinical trial on the lateral-Trendelenburg position (LTP) vs. the semi-recumbent position (SRP) for the prevention of ventilator-associated pneumonia. Here we appraise hospital mortality risks associated with both interventions. Methods: We conducted a randomized, single-blind, controlled study in 17 European centers and 1 in North America. Critically ill, mechanically ventilated patients were randomized to be positioned in LTP or in the SRP. We evaluated all-cause hospital mortality. Also, in a post-hoc interaction exploratory analysis, we assessed mortality risks in patients with or without pulmonary infiltrates upon randomization. Results: A total of 2019 adult patients were screened. Three hundred ninety-five patients were randomized, 194 in LTP and 201 in SRP. Hospital Mortality was 31.3% and 37.1% in the SRP and LTP, respectively (RR 1.18, 95%CI 0.90-1.56, p=0.24). Multiple organ failure was the most common cause of death. Hospital mortality was lower in LTP patients without pulmonary infiltrates, in comparison with SRP, but a trend toward higher mortality was found in LTP patients with pulmonary infiltrates vs. SRP patients (RR with pulmonary infiltrates 1.42, 95% CI 1.01-2.00; RR without pulmonary infiltrates 0.83, CI 0.52-1.33, p=0.07 for heterogeneity). Conclusions: We found a trend toward higher hospital mortality rates in LTP patients with baseline pulmonary infiltrates. These results call for a comprehensive analysis of potential risks associated with LTP in this specific population.