Duration of the first prone positioning maneuver and its association with 90-day mortality in patients with acute respiratory failure due to COVID-19: A retrospective study of time terciles.

Objective: To investigate the association between the duration of the first prone positioning maneuver (PPM) and 90-day mortality in patients with C-ARDS.

Design: Retrospective, observational, and analytical study. Setting: COVID-19 ICU of a tertiary hospital. Patients: Adults over 18 years old, with a confirmed diagnosis of SARS-CoV-2 disease requiring PPM. Interventions: Multivariable analysis of 90-day survival. Main variables of interest: Duration of the first PPM, number of PPM sessions, 90-day mortality.

Results: 271 patients undergoing PPM were analyzed: first tertile (n = 111), second tertile (n = 95) and third tertile (n = 65). The results indicated that the median duration of PDP was 14 h (95% CI: 10-16 h) in the first tertile, 19 h (95% CI: 18-20 h) in the second tertile and 22 h (95% CI: 21-24 h) in the third tertile. Comparison of survival curves using the Logrank test did not reach statistical significance (p = 0.11). Cox Regression analysis showed an association between the number of pronation sessions (patients receiving between 2 and 5 sessions (HR = 2.19; 95% CI: 1.07-4.49); and those receiving more than 5 sessions (HR = 6.05; 95% CI: 2.78-13.16) and 90-day mortality.

Conclusions: while the duration of PDP does not appear to significantly influence 90-day mortality, the number of pronation sessions is identified as a significant factor associated with an increased risk of mortality.