Sodium bicarbonate has been thought to be effective for hypoxic
lactic acidosis, but recently its adverse reactions have been pointed out. Therefore, the effects of NaHCO3
therapy in hypoxic
lactic acidosis were evaluated in the anesthetized dog. Studies were carried out in four groups of adult mongrel dogs. The first group received control ventilation with hypoxic gas (5%O2 + 95%N2) and NaHCO3
therapy to adjust blood base excess. The second group did not receive NaHCO3
therapy after control ventilation with hypoxic gas. The third group breathed hypoxic gas spontaneously and received NaHCO3
therapy. The fourth group did not receive NaHCO3
therapy during spontaneous breathing of hypoxic gas. The changes of acid-base balance, CO2 and
lactate of arterial blood and cerebrospinal fluid (CSF) were analysed in each dog. The conclusions were as follows; 1. The NaHCO3
therapy is not necessary for hypoxic
lactic acidosis under proper ventilation, if arterial blood pH does not fall extremely. 2. The CSF acid-base balance is kept within normal ranges, so that the NaHCO3
therapy is not necessary from this point of view.