Effects of dichloroacetate in the treatment of hypoxic lactic acidosis in dogs.

The metabolic and systemic effects of dichloroacetate (DCA) in the treatment of hypoxic lactic acidosis were evaluated in the dog and compared with the infusion of equal quantities of volume and sodium. Hypoxic lactic acidosis was induced by ventilating dogs with an hypoxic gas mixture of 8% oxygen and 92% nitrogen, resulting in arterial PO2 of less than 30 mmHg, pH below 7.20, bicarbonate less than 15 mM, and lactate greater than 7 mM. After, the development of hypoxic lactic acidosis dogs were treated for 60 min with either DCA as sodium salt or NaCl at equal infusions of volume and sodium. Dogs treated with DCA showed a significant increase of arterial blood pH and bicarbonate, and steady levels of lactate, whereas NaCl resulted in further declines of blood pH and bicarbonate, and rising blood lactate levels. Overall lactate production decreased during therapy with either regimen, but hepatic lactate extraction increased significantly with DCA, while it remained unchanged with NaCl. Tissue lactate levels in liver and skeletal muscle decreased significantly with DCA treatment but were unchanged with NaCl. Additionally, an increase in muscle intracellular pH was observed only in DCA treated dogs. A possible mechanism for the observed actions of DCA might be related to a significant increase in oxygen delivery to tissues. Such an effect was found with DCA administration, but was not observed with NaCl therapy. In conclusion, DCA therapy in hypoxic lactic acidosis has beneficial systemic effects compared with therapy with NaCl. DCA administration is accompanied by increases of blood pH and bicarbonate, a decrease in lactate production, and enhanced liver lactate extraction, and a lowering of tissue lactate levels.