PERIOPERATIVE ASSESSMENT OF CARDIAC ENERGY-METABOLISM BY MEANS OF ARTERIO-CORONARY VENOUS DIFFERENCE IN LACTATE CONCENTRATION (ACDL) - A PARAMETER FOR OPTIMIZING VENTRICULAR-FUNCTION OF THE POSTCARDIOPLEGIC MYOCARDIUM

Fourty-three patients undergoing open heart surgery were subjected toextended hemodynamic and metabolic monitoring (arterial and coronary sinus(CS) lactate concentration). In 95% of patients investigated, a significant increase in CS lactate concentration above the arterial lactateconcentration was established at the beginning of reperfusion (RPT). Inthese cases, a decrease in the CS lactate below the arterial concentrationoccurs within the RPT creating a cross-over point (COP) from negative topositive lactate extraction values. Where as the initial rise in CS lactateis an expression of the expected ischemia- induced acceleration ofanaerobic glycolysis, the onset of a positive lactate extraction can berelated to reconsolidation of mitrochondrial oxidative phosphorylation. We found two groups with an early and late COP at 7.2 ± 0.8 min (ECOP) and 42.5 ± 5.2 min (LCOP) (P < 0.005). Whereas a short cross-overtime was associated with a normal postoperative outcome, cardiac recovery was delayed in the LCOP group. With the aid of metabolic monitoring it ispossible to identify the COP and cardiac overload situations and so to optimize the perioperative outcome, especially in selected patients (NYHAstage III/IV, re- operation, high-risk operation). © Springer-Verlag.