The advantage of using continuous positive airway pressure (CPAP) during weaning from mechanical ventilation is unproven.
Methods
Forty-two patients were weaned with pressure support ventilation (PSV) following prolonged mechanical ventilation. The 20 patients in Group A were removed directly from PSV after at least 24 hours of PSV5+5 (5 cm H2O of PSV plus 5 cm H2O of positive end-expiratory pressure). The 22 patients in Group B were weaned for an additional 24 hours on CPAP. Weaning outcome was compared between the 2 groups by xβ.
Results
The work of breathing was lower with PSV5+5 versus CPAP5 (5 cm H2O of CPAP) when all 42 patients were taken together, in the 36 patients who succeeded weaning, and in 6 patients who failed. The work of breathing was not different between Groups A and B for either ventilatory mode. There were no statistical differences between the failure rates in the 2 modes.
Conclusion
The work of breathing during PSV5+5 was lower than during CPAP5. The work of breathing and the weaning outcome were the same in PSV5+5 and CPAP5. Extending weaning with CPAP, following PSV5+5 offered no benefit, but instead imposed an additional load on the ventilatory musculature.
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