Ventilator management using esophageal balloon pressure measurements

Abstract

Mechanical ventilation provides essential support for patients with acute respiratory failure and provides time for these patients to recover from the primary disorder. Ventilator strategies need to provide adequate oxygenation and avoid barotrauma. This trauma develops when some regions of the lungs are overinflated and develops when some regions are underinflated and have cyclical opening and closing during the respiratory cycle. The ARDS network trial demonstrated that a low tidal volume and low pressure strategy improved outcomes. Subsequent trials have tried to determine the optimal PEEP level in patients with moderate to severe ARDS. The use of esophageal balloons provides information about the transpulmonary pressure at the end of inspiration and the transpulmonary pressure at the end of expiration. However, available studies to date do not demonstrate a definite improvement in outcomes in patients with ventilator adjustments based on esophageal pressures. Beitler et al. randomized 200 patients with moderate to severe ARDS into one group in which PEEP titration was based on esophageal balloon pressure measurements, and a second group in which PEEP titration was based on a high FiO2/PEEP table studied in earlier trials. There were no differences in mortality between the two groups. Reanalysis of this information after the trial was completed suggested that transpulmonary pressures in the range of -2 to + 2 cm H2O at the end of expiration were associated with improved outcomes compared to pressures outside that range.