Lower Levels of Positive End-Expiratory Pressure Didn’t Harm Patients Without Acute Respiratory Distress Syndrome
Patricia Kritek, MD
PEEP of ≤5 cm H2O and PEEP of 8 cm H2O resulted in similar outcomes.
Low tidal volume ventilation, often with high levels of positive end-expiratory pressure (PEEP), is the standard of care for patients with acute respiratory distress syndrome (ARDS). Clinicians commonly adopt the same approach to support critically ill patients without ARDS. But could high levels of PEEP actually harm such patients?
Investigators from the Netherlands randomized 969 intubated patients (without ARDS, but assumed to require mechanical ventilation for at least 24 hours) to either high- or low-PEEP strategy. In the high-PEEP group, PEEP was maintained at 8 cm H2O. In the low-PEEP group, initial PEEP was 5 cm H2O, with titration down to 0 cm H2O if oxygenation saturation remained ≥92% with fraction of inspired oxygen (FiO2) no higher than 0.60.
Mean PEEP in the low-PEEP group ranged from 3 to 4 cm H2O during the first 5 days. Patients in the high-PEEP group had significantly higher oxygenation saturations on lower FiO2. Ventilator-free days, intensive care unit length of stay, and mortality were not significantly different between groups. Adverse events also occurred with similar frequency; however, a nonsignificantly greater incidence of rescue maneuvers for severe hypoxemia were required in the low-PEEP group (20% vs. 15%).
Outcomes with lower levels of PEEP were similar to those with PEEP at 8 cm H2O (which most intensivists would not call “high”). Nevertheless, this approach was not clearly beneficial, and a trend toward more-frequent rescue maneuvers for severe hypoxemia in the low-PEEP group is concerning. I don’t think all critically ill patients should be ventilated like those with ARDS, and this study will not change my practice of starting PEEP at 5 cm H2O for most patients.
Algera AG et al. Effect of a lower vs higher positive end-expiratory pressure strategy on ventilator-free days in ICU patients without ARDS: A randomized clinical trial. JAMA 2020 Dec 22/29; 324:2509. (https://doi.org/10.1001/jama.2020.23517)
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