RECOVERY FROM ISCHEMIC ACUTE-RENAL-FAILURE IS IMPROVED WITH ENTERAL COMPARED WITH PARENTERAL-NUTRITION

Objective: To compare measurements of renal function after acute ische mic renal failure in rats fed enterally or parenterally. Design: Prosp ective, randomized, animal trial. Setting: University research laborat ory. Subjects: Male Sprague-Dawley rats (n = 21). Interventions: Anima ls were randomized to receive isocaloric (160 nonprotein kcal/kg/day), or isonitrogenous (1.4 g of nitrogen/ kg/day [100 mmol/kg/day]) enter al (n = 10), or parenteral nutrition (n = 11) through either a gastros tomy tube or a catheter placed in the jugular vein, After the animals received 7 days of assigned feedings, baseline blood samples were coll ected, A right nephrectomy and 45-min left renal pedicle occlusion wer e then performed, One hour after the ischemic injury, assigned feeding s were resumed and continued for 3 days, After ischemic injury, daily blood samples were obtained and 24-hr urine collections were performed , On day 11, animals were killed and the kidney was harvested and fixe d for subsequent microscopic examination. Measurements and Main Result s: Urine was analyzed for concentrations of total urea nitrogen, creat inine, protein, and calcium. Serum was analyzed for creatinine and ure a nitrogen concentrations, Fixed kidney sections were examined for mit otic figures, tubular calcifications, and casts using light microscopy by an investigator blinded to the nutritional regimen, Data are prese nted as mean +/- so or median (range), Percent increase in creatinine clearance from the nadir on day 9 to day 11 was similar to 2.5-fold gr eater in the enteral compared with the parenteral nutrition group (490 +/- 221% vs, 208 +/- 130%; p = .003), Histologic evaluation demonstra ted greater dystrophic tubular calcifications per ten high-power field s in the parenteral compared with the enteral nutrition group (50 [fou r to 85] vs, three [0 to 37]; p = .001), No differences in urine calci um concentration or 24 hr calcium excretion were seen, Conclusion: Rat s given continuous enteral nutrition 7 days before and for 3 days afte r ischemic acute renal failure have improved renal function compared w ith rats given parenteral nutrition.