Pulmonary Oxygenation, Central Haemodynamics and Glomerular Filtration Following Cardiopulmonary Bypass with Colloid or Non-Colloid Priming Solution

Abstract

Plasma colloid osmotic pressure (COP), blood erythrocyte volume fraction (B-EVF), arterial oxygen tension at an inspired oxygen concentration of 30% (P_aO₂ (FIO₂ 0.3)), cardiac index, stroke volume, arterial mean pressure, left atrial mean pressure, pulmonary av-difference of oxygen (C_a-v O₂) and creatinine clearance were studied in 16 patients during isolated aortic valve replacement. The patients were divided into two groups with different priming solutions in the oxygenator. In the noncolloid group 2 000 ml of Ringerdex^® was used, while the colloid group had 1 600 ml of Ringerdex^® and 400 ml of albumin 20% (80 g).

COP differed significantly between the groups (p < 0.01) during and for 1 hour after bypass. The greatest reductions were 56% and 30%, respectively. Haemodilution (low B-EVF) was of longer duration in the colloid group. No differences between the groups were found with respect to pulmonary oxygenation, myocardial behaviour or glomerular filtration rate. Cardiopulmonary bypass produced no changes in cardiac index, stroke volume, arterial mean pressure, left atrial mean pressure, C_a-v O₂ or creatinine clearance in either of the groups. P_aO₂ (FIO₂0.3) remained unchanged in the non-colloid group and showed a small but significant reduction (p < 0.01) in the colloid group. No positive effects of a colloid prime were demonstrated.