Muscle Protein-Synthesis After Operation: Effects of Intravenous Nutrition

Objective: To assess the effect of an elective abdominal surgical operation (open cholecystectomy) on the rate of protein synthesis in skeletal muscle in humans.

Design: Prospective random control trial.

Setting: University hospital.

Subjects: 17 Metabolically healthy patients who were to undergo elective open cholecystectomy.

Interventions: Patients randomised to receive either saline alone (n = 8) or total parenteral nutrition (n = 9) for three days after operation. The rate of protein synthesis in muscle was calculated from the increase in enrichment of (1-C-13) leucine in protein after a flooding dose of (1-C-13) leucine.

Results: Median (quartiles) rate of protein synthesis had decreased on the third postoperative day in the saline group by 49% (from 2.42 [2.03, 2.54] to 1.24 [0.99, 1.63]) and in the group that had received total parenteral nutrition by 54% (from 1.96 [1.90, 2.07] to 0.9110.79, 1.06]) (p < 0.01).

Conclusions: The trauma associated with open cholecystectomy reduced the rate of protein synthesis in skeletal muscle by half in three days, and conventional total parenteral nutrition had no effect on these changes.