Original Article

Heparin Coated Hollow-Fiber Oxygenator Without Systemic Heparinization in Comparison to Classic Bubble and Membrane Oxygenators

Clinic for Cardiovascular Surgery, University Hospital, Zurich, Switzerland

^* Direct communications to: Ludwig K. von Segesser, M.D., Clinic for Cardiovascular Surgery, University Hospital, 8091 Zurich, Switzerland.

Abstract

Heparin surface coated hollow-fiber oxygenators and tubing sets were evaluated without systemic heparinization (surface) in comparison to conventional uncoated membrane (plate) and bubble oxygenators and tubing sets with systemic heparinization (ACT>400 s). Thirteen dogs were perfused for 6 hours with a mean flow of 100 ml/kg min. and either surface (42±9 kg), plate (38±12 kg) or bubble oxygenators (41 ± 18: NS) by cavo-aortic cannulation after median sternotomy. Besides continuous monitoring of hemodynamics, blood samples for blood gas, biochemical and hematological analyses were taken before, after mixing and every 30 minutes thereafter. Throughout perfusion, arterial pH, arterial pCO₂, arterial pO₂ and venous oxygen saturation could be maintained within normal ranges for the three groups. Plasma hemoglobine, however, was significantly lower in heparin-coated equipment (p<0.005), which allowed cardiopulmonary bypass without systemic heparinization and therefore without return of shed blood.