Metabolic Alterations In Head Injured Patients

Abstract

Metabolism in head injured patients has been previously studied with results frequently indicating a persistent hypermetabolic state. A retrospective chart review was conducted on 50 patients admitted to the Neuro Intensive Care Unit in a tertiary care hospital. Patients entered in the study were between the ages of 15 and 85, with an initial Glascow Coma Score of 10 or less. Resting energy expenditure (BEE), and urinary urea nitrogen (UUN) were reviewed for the first 3 weeks of hospitalization and compared to predicted energy expenditure (BEE), and predicted nitrogen requirements. Also investigated was the effect of Initial Glascow Coma Score (GCS), intracranial pressure (ICP), posturing and paralytic agents on REE and UUN. Results of this study indicate there was a significant difference between BEE and REE, and between predicted nitrogen requirements and UUN for all 3 weeks of the study. REE was increased over BEE by 123% in week 1, by 128% in week 2, and by 125% in week 3. UUN was increased over predicted nitrogen requirements by 190% in week 1, by 255% in week 2, and by 266% in week 3. No significant correlations were found when GCS and ICP were compared to REE and UUN (adjusted for IBW). No significant differences were found in REE or UUN (adjusted for IBW) in those patients on paralytic agents, or in those patients who were posturing except for UUN in week 1. In this case, those patients who were posturing had a lower UUN that those patients who were not posturing.We conclude that head injured patients have REE's > BEE's and this increase could not be explained by ICP, posturing or paralytic agents. These patients also remain catabolic as evidenced by elevated UUN levels over the observed 3 week interval.