Original Article

Cardiopulmonary Bypass Without Systemic Heparinization for 24 Hours

Clinic for Cardiovascular Surgery, University Hospital, Zurich, Switzerland

^* Address correspondence to: Ludwig von Segesser, MD., Clinic for Cardiovascular Surgery, University Hospital, CH-8091 Zurich, Switzerland

Abstract

Cardiopulmonary bypass without systemic heparinization was realised by means of heparin surface COATED oxygenators and tubing sets and analysed in comparison to UNCOATED oxygenators and tubing sets with systemic heparinization (ACT>400s). Seven dogs were perfused for up to 24 hours (when perfusion was electively terminated) with a pumpflow of 50 ml/min/kg bodyweight and either heparin surface COATED equipment (34±5 kg) or UNCOATED equipment (40±7 kg) by cavo-aortic cannulation after median sternotomy. Besides continuous monitoring of hemodynamics, blood samples for blood gas, biochemical and hematological analyses were taken before, FIVE minutes after beginning of cardiopulmonary bypass and at regular intervals thereafter (see chart on page 82).

Mean duration of perfusion was 23±2 hours for COATED versus 20±5 hours for UNCOATED. Adequate gas exchange was obtained with COATED and UNCOATED equipment throughout the perfusion. Plasma hemoglobin production was significantly lower with COATED equipment which allowed open-chest cardiopulmonary bypass without return of shed blood for 13±1 hours.