Metabolism of D lactate in patients receiving hypertonic sodium lactate solution

The use of hypertonic saline solutions for resuscitation of patients with a decreased extracellular fluid volume is generating more clinical interest. One of the solutions, hypertonic lactated Ringer's solution (HLS), contains lactate in both the D(-) and L(+) forms. Because humans lack D lactate dehydrogenase, the metabolism of D lactate in patients receiving large amounts of lactate in a clinical setting was examined. Three patients undergoing extensive aortic surgical procedures and receiving HLS for replacement of perioperative fluid loss were studied. These patients were given an average of 27 grams of D lactate in a 24 hour period and excreted 8 per cent of the total dose in the urine. The average maximum elevation of D lactate in the serum of 3.53 millimoles per liter. Pharmacokinetic analysis revealed a half-life of D lactate in the serum of 36.4 minutes. The volume of distribution was 20 per cent of the body weight. These results demonstrate that D lactate is metabolized rapidly even when given in large amounts to humans during the perioperative period. Whether or not this metabolism occurs during hypoperfusion is not known.