A study of parenteral versus enteral nutrition following caecal ligation and puncture in the rat: Influence on survival and tissue protein turnover

Background & aims: Methods of nutritional management in abdominal sepsis remain controversial. Methods: Sprague Dawley rats were either fed via a central line in the right internal jugular vein or duodenally via a gastrostomy tube, and were randomised to undergo either caecal ligation and puncture (CLP) or laparotomy only. Post-operatively, animals received either parenteral nutrition, enteral nutrition or saline only (parenteral and enteral nutrition protocols were isocaloric and isonitrogenous). After 72 h, fractional rate of protein synthesis (Ks, %/day) was measured in gastrocnemius muscle and liver, and protein breakdown was measured in incubated epitrochlearis muscles. Serum insulin-like growth factor-I (IGF-I), acid-labile subunit (ALS) and IGF binding protein-1 (IGFBP-1) levels were determined by specific radioimmunoassay methods. Results: After CLP, when compared with starved animals, only enteral nutrition resulted in a significant decrease in survival to 72 h (P<0.001). Parenteral nutrition, but not enteral nutrition, increased muscle (P=0.02) and liver (P<0.001) Ks, IGF-I (P<0.001) and ALS levels (P<0.001), whereas both parenteral and enteral nutrition reduced IGFBP-1 levels (P<0.001). Neither enteral nor parenteral nutrition reduced protein breakdown in septic animals. Conclusions: In this model of severe abdominal sepsis where gut function cannot be assessed, enteral nutrition was associated with increased mortality and was less effective than parenteral nutrition in augmenting muscle and liver protein synthesis.