[Continuous positive airway pressure in the treatment of postoperative hypoxia]

The physiopathology of postoperative hypoxia has been analysed, the cause being identified in the worsening of the V/Q ratio consequent on the reduction in CFR. By increasing CFR, CPAP reduces the superimposition of Tidal Volume and Closing Volume, thus reducing dysventilated zones and thereby improving the V/Q ratio and oxyaemia. With these premises, 18 patients undergoing cholecystectomy were examined; 8 of them were treated in the postoperative period with CPAP at pre-established intervals. The results confirm its effectiveness in terms of PaO2 improvement and the need for constant administration, considering that the benefits are lost when the patient is disconnected from the mask.