Protein sparing during general anesthesia with a propofol solution containing medium-chain triglycerides for gastrectomy: comparison with sevoflurane anesthesia.

Purpose: Despite the importance of the inhibition of catabolic response to surgery, the effects of different anesthetic techniques on the catabolic response in surgical patients are controversial. This study compared the endocrine-metabolic responses and protein catabolism during gastrectomy in patients who received either sevoflurane or propofol anesthesia with remifentanil.

Methods: Thirty-seven patients (American Society of Anesthesiologists status I-III) aged 20-79 years undergoing elective gastrectomy were randomly assigned to receive sevoflurane anesthesia with remifentanil (n = 19) or intravenous propofol anesthesia (Propofol-Lipuro(®) 1 %; B. Braun, Melshungen AG, Germany) with remifentanil (n = 18). Urine samples were collected every 1 h after skin incision (0 h) and the urinary 3-methylhistidine:creatinine ratio (3-MH/Cr ratio) was used as a marker of protein catabolism. Respiratory quotient was measured during a 1 h period following skin incision.

Results: The 3-MH/Cr ratio significantly increased at 1-2 and 2-3 h compared to 0 and 0-1 h in both groups, but the propofol group exhibited a lower 3-MH/Cr ratio (nmol/μmol) than the sevoflurane group at 1-2 h (15.7 vs. 18.2, P = 0.012) and 2-3 h (15.9 vs. 18.1, P = 0.025). A difference was observed in the respiratory quotient between the sevoflurane and propofol groups (0.726 vs. 0.707, P = 0.003).

Conclusion: A lower 3-MH/Cr ratio and a lower respiratory quotient during propofol anesthesia, compared to those exhibited during sevoflurane anesthesia, suggest that protein sparing probably occurs through the utilization of medium-chain triglycerides contained in the fat emulsion of propofol solution as a fuel source.