PATTERNS OF ENERGY-EXPENDITURE IN INTENSIVE-CARE PATIENTS

We studied the changes in energy expenditure (EE) in response to multiple injury (n = 6), subarachnoidal hemorrhage (n = 8), low-cardiac-output syndrome after open-heart surgery (n = 6), and uncomplicated coronary artery surgery (n = 10). Measurements were made during 5 consecutive days. In the multiple injury group, EE was 30% higher than predicted basal EE (range 10-52%) within 27 h after trauma, and this hypermetabolism remained unchanged throughout the study. After subarachnoidal hemorrhage, EE was 18% higher than predicted (range 0-45%) and the operation caused only a minor further increment in EE. Also, these patients remained hypermetabolic throughout the study. In the low-cardiac-output syndrome group, the increase in EE was less prominent (mean 15%, range 0-34%), but the pattern of hypermetabolism was similar to that observed in the multiple injury and subarachnoidal hemorrhage groups. The metabolic response to uncomplicated coronary artery surgery resembled the response to general surgery. We conclude that 1) there is an early consistent increase in EE in various groups of surgical intensive-care patients; 2) with appropriate treatment of the circulation, a prompt hypermetabolic response to surgical trauma is maintained even during low-cardiac-output syndrome; and 3) the marked hypermetabolism after subarachnoidal hemorrhage at the central nervous system is an integral part of the hypermetabolic response to injury.