The Influence of Paralytics on the Safety and Efficacy of Prone Positioning in Covid19 ARDS

Abstract

Rationale: Prone positioning has proven benefit but is generally underutilized in moderate to severe Acute Respiratory Disease Syndrome (ARDS). Common practice includes administering neuromuscular blockade [paralytic medication] when proning this population, despite equivocal data regarding benefits of routine paralysis in ARDS. During the COVID19 pandemic, drug shortages and other factors have driven clinicians to prone patients without therapeutic paralysis. Recent publications also suggest prone positioning may be beneficial for non-intubated (non-paralyzed patients). We hypothesized that intubated patients with COVID19-related ARDS can be safely proned without therapeutic paralysis and would experience similar improvement in gas exchange (as evidenced by improved PF [Pa02/Fi02] and SF [Sp02/Fi02] ratios). Methods: Observational data on ICU patients were collected at a large tertiary university hospital from March to September 2020. Clinical teams directed use of sedatives, paralytics, mechanical ventilation settings, and timing of prone vs. supine positioning and blood draws. Comparison of demographics, gas exchange in supine and prone positions (within the same subjects), as well as oxygen requirements, ventilator settings, adverse events and hemodynamic parameters were analyzed using descriptive statistics. Results: Among our cohort of 156 patients, a total of 15 patients were identified that changed from supine to prone position with and without the use of paralytics while in the ICU. All 15 patients had moderate to severe ARDS per the Berlin Criteria, secondary to COVID19. PF and SF ratios were compared in the same patient before and after proning with and without paralytics (within subject comparisons). All groups had an improvement in both average PF ratio (34.7% with and 24.0% without paralysis, p=0.52) and average SF ratio (5.2% with and 6.1% without paralysis, p=0.92) after proning (Figure 1). There were no serious adverse events associated with prone positioning with or without paralytics. Conclusions: When proning patients with COVID19 ARDS, we found no statistically significant difference to support routine use of paralytics when proning. Safety and efficacy were similar when COVID19 patients were being proned with or without neuromuscular blockade. Use of paralytic medication should be an individualized decision rather than given routinely. Larger randomized controlled trials comparing proning with or without paralysis are needed to identify the optimal approach in this population.