Incidence and significance of lobar atelectasis in thoracic surgical patients

Lobar atelectasis, defined by complete lobar collapse and mediastinal shift on chest roentgenogram, represents one extreme form of postoperative atelectasis. We have evaluated the incidence and clinical significance of lobar atelectasis in a thoracic surgical patient group. A retrospective review was done of patients who underwent pulmonary resection over a 2-year period to determine patient characteristics, contributing comorbidities, and associated perioperative care factors. Lung resections were performed for both benign and malignant disease through open or video-assisted techniques. One hundred eighty patients had pulmonary resection, 101 males and 79 females, and they were divided into three groups: I, no complications (112 patients, 62%); II, complications unrelated to lobar atelectasis (60 patients, 33%); and III, complications of lobar atelectasis (8 patients, 5%). There was one death in the series, in the lobar atelectasis group (III). Mean age for the entire group was 64.5 +/- 12.5 years; however, patients in Groups II (67.3 years) and III (69.6 years) were significantly older than in Group I (P < 0.02). Mean hospital length of stay in Group I was 6 +/- 3 days, whereas that in Group II was 13 +/- 12 days (P < 0.001), and in Group III it was 27 +/- 31 days (P < 0.001). In addition, patients who developed lobar atelectasis were more likely to be male (88% vs 48%, P = 0.034), had a longer ICU length of stay (P < 0.001), were more likely to have two or more comorbidities (P < 0.05), and had a lower forced expiratory volume in 1 second (2.34 +/- 0.90 vs 1.96 +/- 0.63). All patients in the lobar atelectasis group were operated on for malignancy, but this was not significantly different from the other groups. None of the 16 patients who had thoracoscopy developed lobar atelectasis, but this also was not a significant finding. We conclude that severe postoperative atelectasis occurs as lobar atelectasis in approximately 5 per cent of patients who undergo pulmonary resection and significantly adds to the intensive care unit and hospital length of stay. The etiology of lobar atelectasis appears to be multifactorial and warrants further study to define mechanisms of occurrence and their prevention.