Assessment of two venous drainage techniques in coronary artery bypass graft surgery

We compared the influence on immediate postoperative cardiac performance, incidence of supraventricular tachyarrhythmia, fluid balance, and respiratory function of two methods of venous drainage during cardiopulmonary bypass (CPB). Two groups of 50 patients were studied. All 100 patients were operated electively for coronary artery bypass grafting. In group 1, cardiac drainage was achieved by using a two-stage cavo-atrial cannula, group 2 patients had drainage cannulae in the superior and inferior vena cava with caval tapes. There were no significant differences between both groups regarding postoperative hemodynamics. Right ventricular stroke work index in groups 1 and 2 differed insignificantly. The incidence of episodes of supraventricular tachyarrhythmia were 19 in group 1 and 23 in group 2 (p NS). Peroperative fluid balance was higher in group 1, but hematocrit during CPB was in the same range. Blood gas analysis values did not differ among the groups during the first 32 hours. The average duration of assisted ventilation was 30.3 +/- 5.4 hours in group 1 and 27.8 +/- 3.1 hours in group 2 (p NS). Thus, in patients undergoing coronary artery bypass grafting with standard techniques of intermittent cardioplegia, double caval cannulation is not superior to single atrio-caval drainage as far as postoperative left and right heart performance, and prevention of supraventricular tachyarrhythmia is concerned. Single cannulation did not increase the risk of undue hemodilution or respiratory dysfunction.