A comparison of flat-sheet and hollow-fiber membrane oxygenators: the Shiley M-2000 vs. the Bentley BOS-CM 40

To compare new flat-sheet and hollow-fiber membrane oxygenators for use in cardiopulmonary bypass, we randomly divided 40 coronary artery surgery patients into 2 groups of 20 patients each. The Shiley M-2000 flat-sheet membrane oxygenator was used in 1 group, and the Bentley BOS-CM40 hollow-fiber membrane oxygenator was used in the other group. Both oxygenators allowed for adequate transfer of oxygen and carbon dioxide. At the end of perfusion, the platelet counts were significantly lower and the arterial pH significantly higher in the Shiley group than in the Bentley group. The other hematologic parameters, as well as postoperative blood losses, were similar in the 2 groups, but were also similar to those reported earlier with respect to bubble oxygenators. On the basis of these results, we conclude that, for routine short-term perfusion, these new membrane oxygenator models, while marginally different from one another, offer no real advantage over bubble models.