Airway occlusion pressure (P0.1)-a useful predictor for the weaning outcome in patients with acute respiratory failure-.

Twenty-five patients who required mechanical ventilatory support (MVS) after major surgery or severe burns were studied to determine whether airway occlusion pressure (P(0.1)) is a clinically useful indicator to predict the success or failure of the weaning trial. A total of 33 weaning trials were attempted on these patients. Of the 33 trials, 24 were followed by successful weaning and 9 by failure. Although the success group, when compared with the failure group, had a lower respiratory rate ( P << 0.001), a lower minute ventilation ( P << 0.001), a higher maximal voluntary ventilation to minute ventilation ratio ( P << 0.01) and a higher forced vital capacity ( P << 0.05), no threshold values separated the success from the failure group. The alveolar-arterial P(O)(2) gradient, with an F i(O)(2) of 1.0, in weaning success and failure showed no statistical difference. In contrast, all patients in the success group had a P(0.1) of less than 3.5 cmH(2)O and those in the failure group had a P(0.1) of greater than 3.5 cmH(2)O ( P << 0.001). We conclude that P(0.1) is a clinically superior indicator for discontinuing MVS in patients with acute respiratory failure.