Preoperative pulmonary preparation of patients with chronic obstructive pulmonary disease: a prospective study.

A group of 157 patients with chronic obstructive pulmonary disease who were treated before surgery using a standardized pulmonary preparation underwent physiologic assessment both before and after the prophylactic program. The postoperative course of each patient also was evaluated to assess the incidence of respiratory morbidity and mortality. Although many physiologic values were statistically improved after the pulmonary preparation, most of the changes are of doubtful functional significance. It is difficult to determine which patients will develop pulmonary complications not requiring mechanical ventilation, but the group requiring this type of support appears to be predictable on the basis of the severity of their pulmonary functional impairment and their lack of response to the standard pulmonary preparation used. The single most reliable test for this purpose was the mean forced expiratory flow during the middle half of the forced vital capacity. The frequency of postoperative respiratory complications was related to the type of operation, with the highest incidence occurring in the group that had extensive upper-abdominal surgery. While the occurrence of these complications was significantly reduced in patients undergoing a standard preoperative pulmonary preparation, the explanation for the beneficial effect of this procedure is not apparent.