Membrane versus bubble oxygenator for cardiac operations. A prospective randomized study.

The advantages of membrane oxygenators over bubble oxygenators for cardiopulmonary bypass during clinical cardiac operations are controversial. A prospective randomized double-blind experimental design was utilized in 64 adult patients undergoing elective cardiac operations with either the Travenol microporous polyprolyene membrane oxygenator or the Bentley Q-100 bubble oxygenator. Sixteen patients in each group underwent coronary artery bypass grafting (CABG) and 16 underwent valvular or other types of operation. The two oxygenator groups were comparable in terms of patient characteristics and perioperative management. Both oxygenators functioned acceptably for an average duration of 115 minutes. Higher relative platelet counts (percent of control) were observed immediately after bypass in CABG patients in whom the membrane oxygenator was used. Otherwise, no significant differences were noted in objectively assessed results between the two oxygenators in regards to bleeding, pulmonary, renal, cardiac, and neurologic function, duration of ICU stay, and postoperative hospital stay. Thus no significant advantages in terms of clinical results could be detected with this type of membrane oxygenator versus another type of bubble oxygenator for elective cardiac operations in adults.