The Pathogenesis of Postoperative Atelectasis

Atelectasis was determined by auscultation in 151 patients after abdominal surgery. The roentgenographic findings correlated well with auscultatory evidence of atelectasis. A carefully taken respiratory history was as helpful as pulmonary function tests in predicting postoperative atelectasis. The incidence of atelectasis was related to duration of surgery but not to age or obesity. Temperature elevation on the first postoperative day was directly related to the degree of atelectasis, but the white blood cell count (WBC) elevation was inversely related. No correlation was found between the bacteriologic state of the lower respiratory tract at the time of surgery, determined by an endotracheal aspirate culture, and the incidence of postoperative atelectasis, temperature, or WBC elevation. On the basis of this study, atelectasis is shown not to be related to an infectious process.