Time-dependent effects of prone position on ventilation-perfusion matching assessed by electrical impedance tomography in patients with COVID-19 ARDS: sub-analysis of a prospective physiological study.
Summary
In 18 ventilated COVID-19 ARDS patients, the initial prone session improved oxygenation and V/Q matching by enhancing ventilation distribution and reducing low V/Q regions; over time, perfusion redistribution further improved matching. Benefits waned after returning to supine, highlighting dynamic, time-dependent mechanisms.
Key Findings
- Prone positioning improved oxygenation and V/Q matching early by enhancing ventilation distribution and reducing low V/Q regions.
- Perfusion redistribution over time further improved V/Q matching during the prone session.
- After returning to supine, V/Q mismatch increased, indicating transient benefits.
Clinical Implications
Consider longer or repeated prone sessions and use monitoring (e.g., EIT where available) to tailor duration, acknowledging that gains may diminish after supination.
Why It Matters
Provides mechanistic, time-resolved insight into how prone positioning improves V/Q matching, potentially guiding session duration and monitoring strategies.
Limitations
- Small single-cohort sample (n=18) limits generalizability and statistical power.
- COVID-19 ARDS specificity may not fully extrapolate to non-COVID ARDS.
Future Directions
Larger multicenter studies to validate EIT-guided titration of prone duration and to test whether time-adaptive protocols improve patient-centered outcomes.
Study Information
- Study Type
- Cohort
- Research Domain
- Pathophysiology
- Evidence Level
- III - Prospective physiological cohort (sub-analysis) with device-based monitoring
- Study Design
- OTHER