Measurement of lactate extraction ratio by centrifugal analyzer to assess myocardial ischemia.

The measurement of blood lactate to determine myocardial lactate extraction ratio requires a high degree of within-run precision, since small changes between arterial and coronary sinus lactate may occur. These changes in man may take place at lactate levels in the normal range, 5-18 mg/dl (0.56-2.00 mmol/l). The authors have developed a method for blood lactate determination utilizing commercially available reagents in a centrifugal analyzer (Centrifichem). Within-run precision in the low normal range, 5.4 mg/dl (0.60 mmol/l), showed a coefficient of variation of 7%. Precision extends to 50 mg/dl (5.55 mmol/l), and agreement with blood lactate values obtained with the Dupont ACA is good.