(1167) Proning in Acute Respiratory Distress Syndrome: To Paralyze or Not to Paralyze, That's the Question

Introduction: Prone positioning in acute respiratory distress syndrome (ARDS) has been shown to reduce mortality. Greater than 90% of patients received neuromuscular blocker (NMB) infusions in the PROSEVA trial. NMB infusions without prone positioning have not been shown to improve outcomes. The purpose of this study is to evaluate clinical outcomes in patients with ARDS that underwent prone positioning while receiving mechanical ventilation (MV) that received a NMB infusion compared to those who did not.

Methods: This was an IRB approved, retrospective, cohort study that included mechanically ventilated adult patients with COVID-19 diagnosed with moderate to severe ARDS (PaO2:FiO2 < 150) admitted to the intensive care unit (ICU) at a large, academic medical center. All patients received prone positioning for at least 12 consecutive hours on at least 1 day of MV. The intervention group included patients that received a NMB infusion for at least 12 hours while receiving prone positioning. The control group included those that did not receive a NMB infusion for at least 12 hours. The primary outcome was the difference in the alive and ventilator free score at 28 days between groups. A 50% threshold difference between groups was utilized to determine clinical significance. Secondary outcomes included adverse events, sedation requirements, length of ICU stay, 28-day mortality, and disposition. Statistical tests included chi-squared tests for nominal data, Mann-Whitney U for ordinal data, and parametric T-test for continuous data.

Results: A total of 202 patients were included, 101 in each group. No differences were present in baseline demographics or severity of illness between groups. There was a statistically significant difference in the primary outcome of alive and ventilator free score at 28 days between the intervention and control group (20.5 vs 11.5%; 8.8% [95% CI: 7.8-9.8]). This finding did not meet the 50% threshold set for clinical significance. The intervention group had higher use of midazolam (73.3 vs 59.4%, p=0.037). No differences were noted in any other secondary outcome.

Conclusions: Continuous NMB infusions in MV patients with moderate to severe ARDS undergoing prone positioning conferred no additional benefit compared to deep sedation alone in days alive and ventilator free score at 28 days.