PEEP therapy for patients with pleurotomy during coronary artery bypass grafting

Severe pulmonary oxygenation impairment resulting from peripheral lung atel ectasis occurred in some patients with pleurotomy during the harvest of the internal mammary artery graft followed by coronary artery bypass grafting (CABG). We studied the efficacy of intraoperative positive end-expiratory a irway pressure (PEEP) therapy for the prevention of postoperative pulmonary oxygenation impairment. A total of 66 patients with solitary CABG procedur e were included in this study. The pleural cavity was intraoperatively open ed in 44 patients and not opened in 22. PEEP therapy was not used in any pa tient before May 1996 (referred to herein as the former period) and was use d more recently in eight patients with pleurotopmy (referred to herein as t he latter period). PEEP was initiated immediately after pleurotomy during t he harvest of the internal mammary artery graft. Without PEEP therapy, valu es of PaO2, A-aDO(2), and respiratory index (RI) were worse in patients wit h pleurotomy than in those without pleurotomy. Meanwhile, there were no maj or differences in these values between patients with or without pleurotomy after the induction of PEEP therapy. Respiratory insufficiency (A-aDO(2) > 400 mmHg and RI > 1.5) was detected in six patients with pleurotomy in the former period. Three of these six patients required over 1 week of long-ter m mechanical respiratory support. No respiratory insufficiency occurred in patients of the latter period. In conclusion, PEEP therapy, which is initia ted just after pleurotomy, may prevent oxygen impairment and pulmonary atel ectasis after extracorporeal circulation (ECC) and is recommended for patie nts with pleurotomy, especially for patients with preoperative low respirat ory function.