Original Article

Comparison of Terumo Hollow Fiber Membrane and Harvey 1500 Bubble Oxygenators Using Red Cell Microrheology Analysis during Cardiopulmonary Bypass

Department of Thoracic and Cardiovascular Surgery, Sahlgrenska Hospital, University of Goteborg, Gothenburg, Swedan

^* Direct communications to: Ali BelbouL Department of Thoracic and Cardiovascular Surgery. Sahlgrenska Sjukhuset. S-413 45 Gothenburg. Sweden.

Abstract

(J. Extra-Corpor. Technol. 79(2) p. 209–215, Summer 1987, 47 refs.) Seventy-three patients undergoing cardiopulmonary bypass (CPB) were prospectively randomized into two groups to compare the effect of membrane (Terumo hollow-fiber [MO]); versus bubble (Harvey 1500 [BO]) oxygenation on red blood cell (RBC) deformability. Comparison of blood trauma was done by measuring the red cell filtration rate (RFR) which reflects changes in RBC deformability. In patients with a high (> 30 ul/sec) RFR before CPB, the M0-1 subgroup showed significantly (p < 0.05) lower reductions of RFR during CPB compared to the B0-1 subgroup. In patients with a low (< 30ul/sec) RFR before CPB, the M0-2 subgroup showed a significantly (p < 0.01) lower loss of RFR compared to the B0-2 subgroup. The use of blood gas-estimations also revealed that hyperoxia was more frequent in the BO group. The frequency of normal pO₂ levels (75-97 mmHg) at 30 min., 60 min. and 90 min. of CPB in the MO group was 65%, 43% and 77% compared to 22%, 11% and 11% (p < 0.01) respectively in the BO group. The earliest significant RFR differences between the MO and BO groups could be detected at 30 minutes of CPB; differences in plasma hemoglobin reached significance after one hour of CPB. This study demonstrates a greater deleterious effect on red blood cells when a BO is used for CPB.