Improvement of 'dynamic analgesia' does not decrease atelectasis after thoracotomy

There is still controversy concerning the beneficial aspects of 'dynamic an algesia' (i.e. pain while coughing or moving) on the reduction of postopera tive atelectasis. In this study, we tested the hypothesis that thoracic epi dural analgesia (TEA) prevents these abnormalities as opposed to multimodal analgesia with Lv. patient controlled analgesia (i.v. PCA) after thoracoto my. Fifty-four patients undergoing thoracotomy (lung cancer) were randomly assigned to one of the two groups. Clinical respiratory characteristics, ar terial blood gas, and pulmonary function tests (forced vital capacity and f orced expiratory volume in I s) were obtained before surgery and on the nex t 3 postoperative days. Atelectasis was compared between the two groups by performing computed tomography (CT) scan of the chest at day 3. Postoperati ve respiratory function and arterial blood gas values were reduced compared with preoperative values (mean (SD) FEV1 day 0: 1.1 (0.3) litre; 1.3 (0.4) litre) but there was no significant difference between groups at any time. PCA and TEA provided a good level of analgesia at rest (VAS day 0: 21 (15/ 100); 8 (9/100)), but TEA was more effective for analgesia during mobilizat ion (VAS day 0: 52 (3/100); 25 (17/100)). CT scans revealed comparable amou nts of atelectasis (expressed as a percentage of total lung volume) in the TEA (7.1 (2.8)%) and in the Lv. PCA group (6.71 (3.2)%). There was no stati stical difference in the number of patients presenting with at least one at electasis of various types (lamellar, plate, segmental, lobar).