Prone position for acute respiratory failure in adults

Area of Science:

• Critical Care Medicine
• Respiratory Physiology
• Clinical Trials Methodology

Background:

• Acute hypoxaemia is a common ICU admission reason, often requiring mechanical ventilation.
• Mortality from acute respiratory distress syndrome remains high at approximately 40%.
• Prone positioning ventilation may improve lung mechanics and gas exchange.

Purpose of the Study:

• To determine if prone ventilation offers a mortality advantage over supine/semi-recumbent ventilation in severe acute respiratory failure.
• To update systematic reviews on prone ventilation for hypoxaemic respiratory failure in adults.

Main Methods:

• Systematic review and meta-analysis of randomized controlled trials (RCTs).
• Searched multiple databases (CENTRAL, MEDLINE, EMBASE, CINAHL, LILACS) up to June 2015.
• Included RCTs comparing prone vs. supine/semi-recumbent positions in mechanically ventilated adults with acute hypoxaemia.

Main Results:

• Nine RCTs with 2165 participants were analyzed.
• Overall mortality showed a non-significant trend favoring prone positioning (RR 0.84-0.86).
• Subgroup analyses suggested mortality benefits for early (<48h), prolonged (≥16h/day), and severe hypoxaemia groups.
• Increased risks of pressure sores and tracheal tube obstruction were noted with prone ventilation; arrhythmias were reduced.

Conclusions:

• No convincing evidence for universal benefit or harm of prone positioning in mechanically ventilated hypoxaemic adults.
• Potential mortality advantages suggested in specific subgroups require further investigation.
• Complications like tracheal obstruction are increased; long-term functional and quality-of-life data are needed.