Prolonged versus standard prone position in covid-19 ventilated patients: a quasi-experimental study

Introduction: Acute respiratory distress syndrome (ARDS) related to COVID-19 increased the number of patients requiring prone position ventilation (PPV). The ProSEVA PPV strategy of daily reproning is resource intensive because each complete PPV cycle takes half an hour of work from 4 experienced operators. Therefore the Standard PPV was extended until 24 to 48 hours. In 2021 Douglas et al. propose the Prolonged PPV strategy for COVID-19 ARDS, returning to the supine position only when the patient has stable gas exchange (Fio2< 60% with PEEP< 10cmH2O). This strategy was secure, but they did not compare the clinical outcomes of the Prolonged against the Standard PPV. In this study, we compare the number of PPV cycles and pressure wounds (PWs) in COVID-19 patients with Standard PPV vs. Prolonged PPV. Methods: Quasi-experimental before-and-after study. We included ventilated patients with PPV indication (criteria from the ProSEVA Trial). Between October 1, 2020, to April 30, 2021, patients with indication of PPV received the standard PPV (24 to 48 hs), and patients hospitalized between May 1, 2021, to October 1, 2021, were treated with the Prolonged PPV. For the primary outcome (number of PPV cycles), we compare the proportion of patients with more than 2 PPV cycles in each group. As a sensitivity analysis, we performed a Fine and Gray regression adjusting by confounders, considering death as a competing event, two PPV cycles as the event, and censoring patients with one PPV cycle at ICU discharge. Results: We included 64 patients in the Standard PPV group and 16 in the Prolonged PPV group. No differences were observed in the number of PPV cycles between groups (patients with more than one cycle: 42.2% [n=27] vs. 62.5% [n=10]; p=0.18). These observations were robust to the sensitivity analysis (the adjusted sHR to have two PPV cycles for the Prolonged PPV group was 1.31 [CI95% 0.63-2.71;p=0.46]). Patients in Prolonged PPV had 2.96 (IQR1.98-3.42) days in PPV vs. 1.98 (IQR1.38-2.94) in the Standard PPV (p=0.03). Chest and abdominal PWs were more frequently in the Prolonged PPV group (chest wounds: 5 patients [31.5%] vs 5 [7.8%]; p=0.024 - abdominal: 3 [18.8%] vs 2 [3.12%]; p=0.02). Conclusions: The Prolonged PPV increases the time in PPV and the PPV-associated PWs but does not reduce the total PPV cycles.