[Catabolic aspects of cranial trauma]

Abstract

During their stay in the intensive care unit, head-trauma patients develop a hypermetabolic and a hypercatabolic status. Their nitrogen balance is highly negative and the muscular proteolysis is largely increased. The nitrogen losses originate mainly in muscles, resulting in muscle wasting and weakness. The whole protein synthesis remains quite normal, but this does not reflect the reality, as muscular protein synthesis is decreased, while hepatic protein synthesis is increased. The increased proteolysis seems to be due to the activation of the three proteolytic pathways, particularly the ATP-ubiquitin-dependent pathway. The causes of the increased muscle proteolysis in head trauma patients remain unclear. The increased glucocorticoid release, which is integrated in the acute phase response to injury, could be one of them. Glutamin, vitamin or zinc supplementation has been proposed in head trauma patients. The use of glucocorticoid antagonists, recombinant growth hormone or anti-cytokines are our fields of research.