Mechanical aids to lung expansion in non-intubated surgical patients.

The reported incidence of postoperative pulmonary complications (PPC) varies markedly with the extent and type of surgery; for many types of major surgery, such as intracranial operations, data are unavailable. After upper abdominal surgery, the incidence ranges from 6 to 70%, depending on the diagnostic criteria used for detection and the physical status of the patients. Thus, the potential for serious PPC after major surgery is so great that some form of preventive respiratory care is mandatory. The most efficient methods remain to be determined. Mechanical aids to lung expansion have received widespread use. Unfortunately, few randomized, controlled trials have been reported, and results are difficult to compare because of important differences in protocol, specific details of therapy, and statistical methods used. We conclude the following: (1) There is little or no evidence documenting the efficacy of intermittent positive-pressure breathing (as customarily used) or blow bottles in decreasing the incidence of PPC. (2) Incentive spirometry may be of value in patients receiving routine "stir-up" regimen (turning, coughing, walking) by surgical housestaff and nurses, but does not appear to decrease further the incidence of PPC in patients treated with systematic preoperative regimens of chest physical therapy. (3) Data on the use of positive end-expiratory pressure and continuous positive airway pressure by face mask are to sparse to permit drawing definite conclusions concerning their efficacy. (4) Incentive spirometry and continuous positive airway pressure by mask are both based on sound physiologic rational and warrant further studies to determine their role in postoperative respiratory care.