The effect of sodium bicarbonate on CBF and intracellular pH in man: stable Xe-CT and 31P-MRS

The effects of sodium bicarbonate on cerebral blood flow (CBF) and intracellular pH were studied in five normal volunteers. CBF and intracellular pH were measured by stable xenon computed tomography and phosphorus-31 magnetic resonance spectroscopy (31P-MRS) respectively. Each patient received 7% sodium bicarbonate (3.5 ml/kg body weight) infused intravenously for 15 minutes. Before and after this injection, CBF intracellular pH and physiological parameters were measured. CBF and PaCO2 were significantly increased. On the other hand, hematocrit and intracellular pH were decreased. These result suggests that three factors are thought to contribute to increase CBF during administration of sodium bicarbonate in humans: 1) arterial dilatation in response to carbon dioxide 2) an decrease of hematocrit 3) intracellular acidosis.