CHANGES IN CEREBRAL OXYGEN-CONSUMPTION ARE INDEPENDENT OF CHANGES IN BODY OXYGEN-CONSUMPTION AFTER SEVERE HEAD-INJURY IN CHILDHOOD

This study examines the relation between cerebral O-2 consumption (CMRo(2)) and the O-2 consumption of the rest of the body (BVo(2)) after severe head injury. Seventy nine serial measurements of whole body O-2 consumption, CMRo(2), plasma adrenaline, T3, and glucagon concentrations were made in 15 children with severe head injuries receiving neurointensive care. Body O-2 consumption was measured with indirect calorimetry and CMRo(2) with the Kety-Schmidt technique. There was no evidence of a significant relation between CMRo(2) and BVo(2). Within each child there were statistically significant positive relations between BVo(2) and adrenaline, T3, and glucagon. By contrast, there was only a weak significant positive relation between CMRo(2) and T3. In conclusion, CMRo(2) and BVo(2) seem to be determined independently after severe head injury. Thus therapeutic measures aiming to reduce CMRo(2) need to be specific to the brain and it should not be assumed that measures which decrease whole body energy expenditure will necessarily have the same effect on CMRo(2).