Indicators of cumulative nitrogen balance and energy in early period of acute pancreatitis are associated with form of disease and in-hospital mortality

Objective. To evaluate cumulative nitrogen and energy balance within 5 days after admission as predictors of form of disease and in-hospital mortality in patients with acute pancreatitis (AP) undergoing early enteral nutrition. Material and methods. A prospective cohort single-center study included 64 patients with predictors of severe AP (APACHE II score >8, CRP>150 mg/L, SOFA score >2) who received early enteral nutrition for 5 days. Urinary nitrogen excretion was determined by urine urea, and nitrogen balance (NB) was subsequently calculated. Resting energy requirement (RER) was determined by indirect calorimetry (IC). Statistical analysis was performed using SPSS-26 software. Results. The following indicators can predict severe form of AP: NB (AUC 0.766, 95% CI 0.649—0.884; p<0.001, Se 0.710, Sp 0.667) with a cut-off threshold -86.4 g of nitrogen per 5 days, amount of nitrogen administered with enteral nutrition (AUC 0.822, 95% CI 0.716—0.928; p<0.001, Se 0.931, Sp 0.636) with a cut-off threshold of 23.24 g of nitrogen per 5 days and energy balance (AUC 0.818, 95% CI 0.713—0.922; p<0.001, Se 0.727, Sp 0.806) with a cut-off threshold 10105 kcal for 5 days. The most accurate model for in-hospital mortality was NB (AUC 0.832, 95% CI 0.722—0.962; p=0.0001, Se 0.600, Sp 0.891) with a cut-off threshold 8.6 g/nitrogen per 5 days, for patients with severe AP — nitrogen excretion with urine (AUC 0.741, 95% CI 0.667—0.875; p=0.043, Se 0.667, Sp 0.875) with a cut-off threshold 52.4 g/nitrogen for 5 days. Conclusion. Indicators of cumulative nitrogen and energy balance within 5 days after admission in early period of acute pancreatitis with predicted severe course of disease and early enteral nutrition may be used as predictors of severe form of disease and in-hospital mortality. The best predictors of severe AP were cumulative (over 5 days) nitrogen, energy and nitrogen intake during this period. The best predictor of in-hospital mortality was nitrogen balance over 5 days, for patients with severe disease (n=33) — nitrogen excretion with urine over 5 days.