Cerebral hemodynamics and metabolism were studied in patients with hepatic and uremic coma. Cerebral blood flow (CBF) was slightly decreased in two patients with hepatic coma from cirrhosis of the liver. In uremia, CBF was conspicuously decreased in one case associated with hypertension, but in two cases it was slightly increased, although in one of them CVR was moderately elevated.
Cerebral vascular resistance (CVR) was not altered in hepatic coma, but in uremia it was remarkably high in two cases and normal in one case.
Cerebral oxygen delivery (CDO
2) was slightly less than normal in hepatic coma, but it was markedly decreased in uremia. Cerebral oxygen consumption (CMRO
2) was very small both in hepatic coma and in uremia.
Cerebral consumption of glucose (CMRgl) showed almost the same tendency in both comatose states. Although CMRgl was significantly higher than normal in both, it was higher in hepatic coma than in uremia.
The blood pyruvate and lactate were elevated in the patients with hepatic coma, and their arterial-cerebral venous differences were higher than normal, but these were not seen in uremia.
It may be said that these results suggest the existence of some differences in the cerebral glucose degradation processes between hepatic coma and uremia, although in both comatose states the reduction of CMRO
2 and increase of CMRgl were seen.
Any marked changes in the blood electrolyte levels were not seen both in hepatic and uremic coma.
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