Abstract
Introduction: The use of extracorporeal circulation (ECC) in cardiac surgery can cause hypercirculatory cardiac failure (HCF). ECC induced release of inflammatory mediators is one mechanism responsible for HCF. Additionally, hemodilution itself can cause a decrease in systemic vascular resistance. Therefore, we prospectively studied the effects of different venous drainage techniques on the incidence of hypercirculatory cardiac failure.¶Methods: After ethical approval and written informed consent, 120 patients scheduled for CABG surgery were randomized into three groups: group A: single atrial cannulation; group B: single atrial cannulation combined with intraoperative hemofiltration to zero fluid balance, and group C: bicaval cannulation with complete venous drainage of cardioplegic solution. Cardioplegia was performed with 2 L of Bretschneider HTK solution into the aortic root. Bypass grafting was performed in moderate hypothermia (32°C). Hemodynamics, use of vasoactive drugs, plasma electrolytes, body temperature, and hemoglobin/hematocrit ratio were recorded. HCF was defined as cardiac output (CO) >6 l min–1, systemic vascular resistance (SVR) <800 dyn sec cm–5 and mean arterial pressure (MAP) <60 mm Hg. Statistical analysis was performed using multiple analysis of variance for repeated measures (MANOVA). A level of p≤0.05 was considered significant.¶Results: No perioperative mortality was observed in the three groups. The incidence of HCF was significantly higher in group A (32%, n=13) and B (40%, n=16) compared to group C (10%, n=4) (p<0.05). Cardiac output in patients with HCF was significantly higher than in patients with No-HCF (Gr.A: 8.2±1.1 vs. 6.0±1.3, Gr.B: 7.8±0.8 vs. 4.7±0.9, Gr.C: 7.4±4.6; p<0.05). In correlation systemic vascular resistance was decreased in patients with HCF (Gr.A: 575±86 vs. 992±232, Gr.B: 603±157 vs. 1134±257 vs. 725±172 vs. 1325±297; p<0.05). Statistical analysis revealed no interaction between HCF and hematocrit, body temperature, plasma levels of sodium and calcium or other hemodynamic parameters like pulmonary artery pressure, pulmonary vascular resistance or heart rate.¶ Conclusions: The results of the present study suggest that single atrial cannulation results in a significantly higher incidence of HCF when compared to bicaval cannulation. A possible explanation for the higher incidence of HCF in group A and B might be the inevitable infusion of cardioplegic solution into the systemic circulation. Perioperative zero flow balanced hemofiltration does not prevent HCF.
Published Version
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