Effects of Alveolar Recruitment on Arterial Oxygenation in Patients After Cardiac Surgery: A Prospective, Randomized, Controlled Clinical Trial

Objective: Pulmonary atelectasis and hypoxemia remain considerable problems after cardiac surgery. The objective of this study was to determine the efficacy of consecutive vital capacity maneuvers (C-VCMs) to improve oxygenation in patients after cardiac surgery. Study Design: Randomized, controlled clinical trial. Setting: Tertiary referral teaching center. Participants: Ninety-five patients requiring elective cardiac surgery with cardiopulmonary bypass (CPB). Intervention: Patients were randomly allocated to either C-VCM or control groups. In the C-VCM group, lung inflation at pressure of 35 cmH₂O was sustained for 15 seconds before separation from CPB and at 30 cmH₂O for 5 seconds after admission to the intensive care unit (ICU). Measurements and Main Results: The primary outcome was the ratio of arterial oxygen tension to inspired oxygen fraction measured at the following predetermined time intervals: after induction of anesthesia, 15 minutes after separation from CPB, after admission to the ICU, after 3 hours of positive-pressure ventilation, after extubation, and before ICU discharge. C-VCM resulted in better arterial oxygenation extending from the immediate postoperative period to approximately 24 hours after surgery at the time of ICU discharge. There were no significant adverse events related to C-VCM application. Conclusion: C-VCM is an effective method to reduce hypoxemia associated with the formation of atelectasis after cardiac surgery with CPB.