[Parenteral nutrition and "hypermetabolic" acute renal failure]. [Parenteral nutrition in septic patients with acute renal failure in polyuric phase]. Improved survival from acute renal failure after treatment with intravenous essential L-amino acids and glucose. Results of a prospective, double-blind study. Effects of different energy intakes on nitrogen balance in patients with acute renal failure: a pilot study. A comparison of essential and general amino acid infusions in the nutritional support of patients with compromised renal function. Total parenteral nutrition with high or low nitrogen intakes in patients with acute renal failure. Clinical and metabolic responses to parenteral nutrition in acute renal failure. A controlled double-blind study. High-dose amino acid infusion preserves diuresis and improves nitrogen balance in non-oliguric acute renal failure.
nan nan nan Thus far, there have been no controlled studies to examine optimal levels of energy provision in critically ill patients with acute renal failure (ARF) receiving artificial nutrition.
                After a 24 h nitrogen-free regimen (20% dextrose), we assigned during an open-label, AB/BA-crossover-trial, 10 ARF patients receiving both total parenteral nutrition (TPN) and renal replacement therapy (seven males; mean age 72 years, range 60-83; mean APACHE II score 27.1, range 23-34, mechanical ventilation 8/10) to a lower calorie-TPN regimen (30 kcal/kg/day) and to a higher calorie-TPN regimen (40 kcal/kg/day), each for 3 days. Nitrogen intake was 0.25 g/kg/day for both regimens. We estimated nitrogen balance, protein catabolic rate and urea generation rate by urea kinetic methods based on both timed blood samples of serum urea and direct urea quantification from dialysis fluid.
                Two patients were excluded from the analysis (due to death and serum triglycerides above 5.1 mmol/l, respectively). Compared with the lower calorie-TPN, the higher calorie-TPN regimen did not improve estimated nitrogen balance [+1.55 g/day (95% confidence interval: -0.95 to +4.05, P = 0.18)], protein catabolic rate [-0.10 g/kg/day (-0.33 to +0.14, P = 0.35)], or urea generation rate [-1.3 mg/min (-5.2 to +2.7, P = 0.46)], whereas it increased serum triglycerides [+1.36 mmol/l (+0.53 to +2.19, P = 0.007)], glucose [+1.15 mmol/l (+0.07 to +2.24, P = 0.041)], insulin need [+20.4 U/day (+8.3 to +32.6, P = 0.006)] and nutritional fluid administration [+468 ml/day (+370 to +566, P<0.001)].
                The present study, conducted in a small group of subjects, shows that in critically ill patients with ARF on a nitrogen intake of 0.25 g/kg/day, an energy provision of 40 kcal/kg/day does not improve nitrogen balance estimates compared with a 30 kcal/kg/day intake; instead, it may increase the risk of artificial nutrition-related side-effects. nan This study was undertaken to assess the clinical and metabolic responses to total parenteral nutrition (TPN) in patients with acute renal failure who could not be nourished adequately through the enteral tract. The TPN provided either about 21 g/day of essential amino acids (EAA) or a larger quantity of essential and nonessential amino acids (ENAA); the ratio of essential to nonessential amino acids in the latter preparation was 1.0:1.0. Attempts were made to give sufficient ENAA nitrogen to equal or slightly exceed the urea nitrogen appearance (UNA). Five patients were randomly assigned to receive TPN with EAA (2.3 g of nitrogen per day) and six patients to receive ENAA (11.3 g of nitrogen per day). Hypotension with trauma or infarcted intestine was the cause of acute renal failure in 10 of the 11 patients. Three of the five patients receiving EAA recovered renal function, and two survived. In the patients receiving ENAA, as compared with those given EAA, UNA was significantly greater (14 +/- 7.4 [SD] vs. 7.5 +/- 3.0 g/day; P less than 0.01), and nitrogen balance, estimated from the difference between intake nitrogen and UNA was slightly, but not significantly, less negative (-3.0 +/- 4.0 vs. -5.2 +/- 2.9 g of nitrogen per day). These preliminary findings suggest that in comparison to TPN with EAA, there is no advantage to larger amounts of ENAA (76 +/- 13 g/day). Studies are indicated to assess whether a multifaced approach using TPN with ENAA and possibly a larger proportion of the branched-chain amino acids, higher energy intakes, anabolic agents, and continuous arterio-venous hemofiltration will improve morbidity and mortality in patients with acute renal failure. 1. Thirty patients with acute renal failure who were unable to eat adequately were evaluated while they received parenteral nutrition with glucose alone (n = 7), glucose and 21 g/day essential amino acids (EAA, n = 11) or glucose, 21 g/day essential and 21 g/day nonessential amino acids (ENAA, n = 12). Energy intake did not differ with the three treatments. Patients were studied in a prospective double blind fashion. 2. Thirteen patients recovered renal function and 11 survived to leave the hospital. Those in whom renal failure was attributed to hypotension and/or sepsis had a poorer recovery of renal function (17%) and survival (17%). Recovery of renal function and survival was greater in patients on the medical service as compared to the surgical service and in those who received more energy. Recovery of renal function was worse in those treated with dialysis. There were no differences in recovery of renal function of survival among the three treatment groups. 3. Many patients were markedly catabolic as indicated by nitrogen balances, urea in nitrogen appearance rates (UNA), serum protein concentrations, and plasma amino acid levels. There was no correlation between the degree of catabolism and recovery of renal function or survival. Mean UNA in individual patients also correlated with body weight. Among the three groups, however, UNA was significantly less with the group receiving EAA as compared to ENAA. 4. Serum protein concentrations were lower than normal in all treatment groups. Serum albumin fell significantly during the treatment in the more catabolic patients. Plasma amino acid levels tended to fall in all three groups and concentrations at the end of the treatment were frequently lower than normal. 5. These data suggest that acute renal failure patients who are unable to eat adequately are often hypercatabolic and have a high mortality, particularly if hypotension or sepsis is the cause of renal failure. The improved survival in those with higher energy intakes, the high rate of net protein breakdown, the low serum protein levels and the reduced plasma concentrations of both essential and nonessential amino acids suggest that greater quantities of energy and both essential and nonessential amino acids may be beneficial to such patients. The effects of protein-enriched diets on glomerular filtration have been described in normal subjects and in patients with chronic renal failure. In acute renal failure, the effects of administration of high rates of protein on renal function and nitrogen balance have not been studied in critically ill patients. The present study examines the effects of large doses of amino acids on the glomerular filtration rate and nitrogen balance in critically ill patients with acute renal failure.
                Fourteen critically ill patients with a creatinine clearance below 50 ml/min and conserved diuresis above 2,000 ml/day received 2000 non-protein kcal/day and either 75 g (Group 1) or 150 g (Group 2) of amino acids parenterally. Renal function tests, fluid balance, sodium and nitrogen balances, and furosemide administration were assessed on day 1 (baseline day when dextrose 5% was administered) and days 2, 3 and 4.
                The two groups were comparable in terms of severity indices, sex and creatinine clearance. Group 2 was significantly older (p < 0.05). Blood urea nitrogen increased significantly in Group 1 but not in Group 2; creatinine clearance remained unchanged in the two groups. Group 2 patients had a significantly more positive cumulative nitrogen balance (-10.5 +/- 17 g/day vs. 9 +/- 8.3 g/day) (p < 0.01), less positive fluid balance (2003 +/- 1336 ml vs. -2407 +/- 1990 ml) and lower furosemide requirement (1003 +/- 288 mg vs. 649 +/- 293 mg) (p < 0.05).
                A high amino acid regimen administered as a part of parenteral nutrition improves nitrogen balance, reduces furosemide requirements and ameliorates water balance in acute renal failure patients with conserved diuresis.
There was insufficient evidence found to support the effectiveness of nutritional support for AKI. Further high quality studies are required to provide reliable evidence of the effect and safety of nutritional support.