Duration of prone position sessions: a prospective cohort study

Area of Science:

• Critical Care Medicine
• Respiratory Physiology
• Pulmonary Medicine

Background:

• Prone positioning (PP) is a key intervention for moderate-to-severe acute respiratory distress syndrome (ARDS).
• Optimal duration of PP sessions for maximizing physiological benefits in ARDS patients remains undetermined.
• This study aimed to determine the time required for maximum physiological effect and identify predictors of survival during PP.

Purpose of the Study:

• To evaluate the optimal duration of prone positioning (PP) sessions in acute respiratory distress syndrome (ARDS) patients.
• To identify physiological parameters that indicate maximum benefit from PP.
• To investigate predictors of patient response and survival during PP.

Main Methods:

• A prospective, monocentric physiological study involving 103 ARDS patients (95%) undergoing 231 PP sessions.
• Measurements included pulmonary mechanics, volumetric capnography, and arterial blood gases before, during, and after PP.
• Dynamic parameters were recorded every 30 minutes during sessions up to 24 hours.

Main Results:

• PP sessions averaged 21.5 ± 5 hours.
• Significant improvements observed in pH, static compliance, and PaO2/FiO2 ratio, with decreases in PaCO2, Pplat, and other parameters.
• Beneficial physiological effects persisted beyond 16 hours and up to 24 hours, with no identified predictors of response.

Conclusions:

• Prone positioning (PP) sessions should be extended to at least 24 hours for ARDS patients.
• Continue PP beyond 24 hours if the PaO2/FiO2 ratio remains below 150.
• No criteria predict which patients will benefit from PP, supporting prolonged, individualized treatment durations.