Mechanical Ventilation Guided by Esophageal Pressure in Acute Lung Injury

Positive end-expiratory pressure (PEEP) is used to improve oxygenation in patients with acute lung injury or the acute respiratory distress syndrome. In this pilot trial, the investigators show that adjusting PEEP with the use of measurements of esophageal pressure to estimate transpulmonary pressure leads to improved oxygenation as compared with the conventional approach to ventilator management. Patients with acute lung injury or ARDS were randomly assigned to mechanical ventilation directed either by esophageal-pressure measurements or according to standard-of-care recommendations. The use of esophageal pressures to estimate the transpulmonary pressure significantly improved oxygenation and respiratory-system compliance. Recent changes in the practice of mechanical ventilation have improved survival in patients with the acute respiratory distress syndrome (ARDS), but mortality remains unacceptably high. Whereas low tidal volumes are clearly beneficial in patients with ARDS, how to choose a positive end-expiratory pressure (PEEP) is uncertain. 1 – 4 Ideally, mechanical ventilation should provide sufficient transpulmonary pressure (airway pressure minus pleural pressure) to maintain oxygenation while minimizing repeated alveolar collapse or overdistention leading to lung injury. 5 In critical illness, however, there is marked variability among patients in abdominal and pleural pressures 6 , 7 ; thus, for a given level of PEEP, transpulmonary pressures . . .