Prone Positioning in Mechanically Ventilated COVID-19 Patients: Timing of Initiation and Outcomes

Abstract

The COVID-19 pandemic led to a broad implementation of proning to enhance oxygenation in both self-ventilating and mechanically ventilated critically ill patients with acute severe hypoxic respiratory failure. However, there is little data on the impact of the timing of the initiation of prone positioning in COVID-19 patients receiving mechanical ventilation. In this study, we analyzed our proning practices in mechanically ventilated COVID-19 patients. There were 931 total proning episodes in 144 patients, with a median duration of 16 h (IQR 15-17 h) per proning cycle. 563 proning cycles were initiated within 7 days of intubation (early), 235 within 7-14 days (intermediate), and 133 after 14 days (late). The mean change in oxygenation defined as the delta PaO₂/FiO₂ ratio (ΔPF) after the prone episode was 16.6 ± 34.4 mmHg (p < 0.001). For early, intermediate, and late cycles, mean ΔPF ratios were 18.5 ± 36.7 mmHg, 13.2 ± 30.4 mmHg, and 14.8 ± 30.5 mmHg, with no significant difference in response between early, intermediate, and late proning (p = 0.2), respectively. Our findings indicate a favorable oxygenation response to proning episodes at all time points, even after >14 days of intubation. However, the findings cannot be translated directly into a survival advantage, and more research is needed in this area.

Keywords: COVID-19; critical care; mechanical ventilation; prone.

Figure 1

Bar chart view of the total number of prone cycles instituted for the number of patients included in the study.

Figure 2

Demonstration of the change in the PaO₂/FiO₂ ratio (a) after each proning cycle per patient, (b) by prone cycle timing from time of intubation: early (<7 days), intermediate (7–14 days), and late (>14 days). The dotted line represents a linear model fitted to all plotted data. The shaded area represents the 95% CI.