Negative- versus positive-pressure ventilation in intubated patients with acute respiratory distress syndrome.

Introduction: Recent experimental data suggest that continuous external negative-pressure ventilation (CENPV) results in better oxygenation and less lung injury than continuous positive-pressure ventilation (CPPV). The effects of CENPV on patients with acute respiratory distress syndrome (ARDS) remain unknown.

Methods: We compared 2 h CENPV in a tankrespirator ("iron lung") with 2 h CPPV.