Carnitine Excretion: A Catabolic Index of Injury

Abstract
In patients with trauma or sepsis, carnitine is known to be produced to a greater extent; deficient production could impair the energy management that is required in such patients. To clarify the requirements of carnitine after injury, we studied carnitine elimination (in 10 critically ill injured patients) both during fasting and early parenteral nutrition. Increased carnitine (mainly, free) output after injury (9.36 ± 1.63 μmol/kg p < 0.02 vs reference) was negatively related to nitrogen balance (p < 0.05) and positively to 3‐methyl‐histidine output (p < 0.01), acting as a market of body mass catabolism. The output of both total and free carnitine progressively decreased (p < 0.01) throughout the course of total parenteral nutrition. In conclusion, our data definitively suggest that carnitine loss after injury reflects body cell mass wastage and does not necessarily mean an increased need. (Journal of Parenteral and Enteral Nutrition 12:35–36, 1988)