[Changes in hemodynamics and volemic status during intraoperative blood exfusion in patients with chronic heart...

Forty-five patients with dilated cardiomyopathy, NYHA Functional Classes III-IV chronic heart failure with left ventricular ejection fraction 26.98+/-7%, who had undergone surgical left ventricular remodeling using an extracardiac conduit in combination with mitral or tricuspid valve correction and blood exfusion, were examined. Central hemodynamic monitoring was performed, by using a Swan-Ganz catheter in all the patients at surgery. In 11 patients, transpulmonary thermodilution in combination with pulmonary artery catheterization with a Swan-Ganz catheter (PICCO-Plus + VOLEF, Pulsion, Germany) was used in 11 patients to monitor central hemodynamics. Right atrial blood autoexfusion was carried out at a volume of 6-10 ml/kg prior to extracorporeal circulation. At blood sampling, blood pressure (BP), heart rate (HR), central venous pressure (CVP), and pulmonary pressure were in the normal range. There were no significant changes in HR, BP, and CVP after blood exfusion. A significant lowering was noted in systolic and diastolic pulmonary pressure by 20-25%. Under the influence of blood exfusion, there was a reduction in cardiac pump function, which appeared as decreases in stroke index by 24% (p < 0.05) and cardiac index by 18% (p < 0.05). The parameters reflecting left and right ventricular myocardial contractility (functional state index, global ejection fraction, and dPmax) underwent no negative changes. According to the changes in systolic and diastolic BP and total peripheral vascular resistance index, left ventricular postload did not change either. At the same time, global end-diastolic volume index was reduced by 22% (p < 0.05), right cardiac and right ventricular end-diastolic volumes were decreased by 20% (p < 0.05) and 23% (p < 0.05), respectively; the left ventricular end-diastolic volume index tended to be lower. These data suggested that diminished cardiac pump function was caused by a predominant reduction in global preload, as evidenced by volumetric monitoring. At the same time the changes in CVP, BP, and HR did not reflect the altered volemic status. To prevent destabilization of the circulatory system, blood should be sampled just before extracorporeal circulation after aortic cannulation.