Haematological characteristics of a new membrane oxygenator: the Cobe CML.

The new Cobe CML membrane oxygenator is more compact than other membrane oxygenators and has a combined venous and cardiotomy suction reservoir. Its size makes it as easy to use as a bubble oxygenator. The studies reported here were designed to show whether the excellent haemocompatibility found with other types of membrane oxygenators had ben compromised by the changes introduced in the Cobe CML oxygenator.

Hematological advantage of a membrane oxygenator over a bubble oxygenator in long perfusions.

To determine whether the large volumes of cardiotomy suction which occur during long perfusions can obscure the hematological advantage of the membrane oxygenator (MO) over the bubble oxygenator (BO), we studied 23 patients undergoing a coronary artery bypass grafting operation with an expected perfusion time of 3 hours (MO group, N = 10, SciMed spiral coil; BO group, N = 13, Shiley 100-A). During MO perfusion we found significantly higher platelet numbers, better platelet function (adenosine diphosphate-induced platelet aggregation), and less hemolysis (plasma hemoglobin), than during the BO perfusion. After the MO perfusion we measured significantly shorter bleeding times (Simplate II) and fewer transfusions of blood products.

Controlled cardiotomy suction during clinical bubble oxygenator perfusions.

Cardiotomy suction causes platelet damage and hemolysis due to air aspiration along with blood suction (uncontrolled suction = US). However, prevention of air aspiration (controlled suction = CS) reduces platelet damage and hemolysis and improves postoperative hemostasis, as only attainable in membrane oxygenator (MO) perfusions. We therefore studied 3 groups of patients subjected to extracorporeal circulation: bubble oxygenator (BO) with CS (n = 10), BO with US (n = 8) and MO with US (n = 10).