Effects of infusion of branched chain amino-acids enriched TPN solutions on plasma amino-acid profiles in sepsis and trauma patients

Total parenteral nutrition with branched chain amino-acids enriched solutions has been advocated in patients with sepsis and stress because of favourable effects on nitrogen balance, protein synthesis and immune competence. The rationale for the use of BCAA-enriched solutions is based on their potential to correct the plasma amino-acid imbalances seen in these patients. In a 7-day prospective randomised study we investigated the effects on plasma amino-acid concentrations of a standard amino-acid solution (15.6% BCAA) and a branched chain amino-acid enriched solution (50.2% BCAA) in 101 parenterally fed patients with carefully assessed sepsis and/or stress scores. The infusion of the BCAA-enriched solution led to an imbalance of the essential plasma amino-acids. The branched chain amino-acids valine, leucine and isoleucine increased significantly while the non-BCAA essential amino-acids decreased significantly. In the standard solution the non-BCAA-essential amino-acids increased significantly with a slow and insignificant rise in the levels of the branched chain amino-acids. We conclude that infusion of a BCAA enriched TPN formulation induced amino-acid profile derangements that can be considered ill-suited to the achievement of anti-catabolic effects.     

Nitrogen sparing effect of ornicetil in the immediate post-operative state—Plasma and muscle amino-acids

In an earlier report we demonstrated that parenteral nutrition (TPN) with addition of 1(+)ornithine alpha-ketoglutarate (Ornicetil^®) markedly improved nitrogen economy in the immediate post-operative period compared to controls given isocaloric and isonitrogenous TPN but without Ornicetil^®. In the present study, plasma and intracellular muscle free amino-acid concentrations were measured in 13 patients before and 3 days after major elective abdominal surgery; seven patients without and six with Ornicetil^® supplementation.The pre-operative values for plasma and muscle free amino-acids did not differ from those derived from age matched health subjects. The direction of post-operative alterations in plasma amino-acid concentrations were similar in both groups, consistent with the earlier reported post-operative pattern, although the elevations of BCAA, proline and ornithine were much more accentuated in the Ornicetil^® group. After surgery the majority of the commonly observed intracellular changes were abolished or minimised in patients receiving Ornicetil^®, while the intracellular depletion of glutamine persisted and the levels of ornithine and proline were markedly elevated as a consequence of Ornicetil^® supply.A tentative explanation for the biochemical action of Ornicetil^® is given.     

Fibronectin levels in stressed and septic patients fed with total parenteral nutrition

Plasma fibronectin concentrations were measured in healthy persons as well as in septic and stressed patients. A decrease in plasma fibronectin concentration was shown in volunteers receiving a low energy (600 kcal), amino acids- and lipid-deficient diet. Increased fibronectin levels were measured in stressed and septic patients, not receiving enteral nutrition, after adequate total parenteral nutrition (TPN during 1 week). It is concluded that total parenteral nutrition facilitates improved fibronectin synthesis in stressed and septic patients. Total parenteral nutrition containing an amino acid mixture rich in branched amino acids (50.2% BCAA) is not superior to TPN containing a standard amino acid mixture (15.6% BCAA) in this respect.     

Variations in plasma amino acids in septic patients subjected to parenteral nutrition with a high proportion of branched-chain amino acids.

Sepsis is characterized by an increase in the plasma concentration of aromatic amino acids (AAAs) and those containing sulfur and a decrease in the branched-chain amino acids (BCAAs). We studied changes in the plasma aminogram of septic patients given different types of total parenteral nutrition (TPN), analyzing variations in accordance with the type of TPN used and the importance that the use of BCAA may have in these patients. We studied 80 patients with peritonitis divided into two groups of 40 patients each: group 1 was given a solution with 22.5% BCAA and group 2 a solution with 45% BCAA. High BCAA content caused an increase in the plasma concentrations of these amino acids and in the BCAA/AAA quotient and a decrease in AAAs. Plasma concentrations of leucine and valine reached high, potentially toxic levels at 15 days when solutions with high BCAA content were used. Glycine increased in group 1, which may be important because of its tendency to produce hyperammonemia. BCAAs are of unquestioned nutritional importance in view of the evidence of changes that take place in muscle protein catabolism and in plasma amino acids. In the phase of increased protein catabolism, we saw a plasma amino acid pattern in keeping with the existing metabolic situation. The need for BCAA diminishes when the hypercatabolic state disappears.     

Plasma amino acids in total parenteral nutrition comparison of continuous and cyclic parenteral nutrition

Cyclic nocturnal total parenteral nutrition (TPN) is a widely used technique but its metabolic consequences have not been fully investigated. The aim of this work was to investigate the influence of infusion rhythm on the plasma amino-acid profile in 12 subjects. During two successive 7-day periods and in a randomly chosen order, they received either standard continuous TPN (TPN_Co), i.e., 24 h a day or cyclic TPN (TPN_Cy), i.e., between 5 p.m. and 9 a.m. Caloric and nitrogen supplies were identical in both periods. Plasma amino-acids were analysed at 8:30 a.m. and 4:30 p.m. on the last day of each infusion period. In contrast to the stability observed in TPN_Co, TPN_Cy led to considerable variations of plasma amino-acid concentrations, creating a profile close to that observed in normal oral feeding conditions. Total 24 h urinary amino-acid elimination and the nitrogen balance did not differ between the two types of TPN. These results show that TPN_Cy induces a metabolic profile close to physiological conditions.     

Branched-chain amino acids metabolic support in surgical patients: a randomized, controlled trial in patients with subtotal or total gastrectomy in 16 Japanese institutions

A prospective, randomized, controlled trial of nutritional effects of branched-chain-enriched amino acid (BCAA) solution was undertaken in 173 surgical patients with gastric cancer. Eighty-six and 87 patients underwent subtotal and total gastrectomy, respectively. The effects were evaluated in total parenteral nutrition (TPN) in an isocaloric/isonitrogenous setting where the major difference between the group was the amount of BCAA received. Each 80 patients in the control and the BCAA groups completed the trial. The group receiving BCAA-enriched amino acid solution demonstrated a statistically significant improvement on days 2 and 3 in nitrogen balance in patients with total gastrectomy. Three-methyl-histidine excretion gradually decreased after day 1, and the values on day 7 were significantly lower than those on day 1 in the BCAA group in both those receiving subtotal and total gastrectomy. There were no significant differences of serum albumin and rapid turnover proteins between the control and BCAA groups in both those receiving subtotal and total gastrectomy. Plasma BCAA level and BCAA to aromatic amino acid (AAA) ratio were significantly higher, and AAA level was significantly lower in the BCAA group than in the control group. There were no serious complications encountered during the observation period in both groups. These results indicated that a BCAA-enriched amino acid solution can improve metabolism and maintains good nitrogen retention without increasing side effects as compared with a conventional amino acid solution for nutritional support of patients who have received subtotal or total gastrectomy.     

Parenteral nutrition support after bone marrow transplantation: comparison of total and partial parenteral nutrition during the early posttransplantation period

OBJECTIVE: Bone marrow transplantation (BMT) usually is indicated if the patient's malignant disease involves the marrow or if hazard to the normal marrow is the limiting factor in the aggressive treatment of disease. The success of BMT depends on a complete team with all the resources needed to ensure optimal results. Aggressive nutrition support after BMT is very important. Adequate parenteral nutrition, total (TPN) or partial, followed by enteral nutrition according to the patient's gastrointestinal function is the important principle. METHODS: Between 1996 and 2000, 60 patients, 46 male and 14 female, received BMT in Chang Gung Memorial Hospital. Their ages ranged from 6 to 54 y. Standard TPN was used in 40 patients after BMT, and partial parenteral nutrition was used in the remaining 20 patients. TPN was enriched with branched-chain amino acids (BCAA) when the patient's liver functions were impaired, and cyclic TPN was shifted when the patient's liver functions persistently deteriorated. RESULTS: Most patients improved their nutrition status and increased their body weights, especially those receiving TPN. The patients receiving partial parenteral nutrition decreased their visceral proteins significantly during the course of parenteral nutrition. The BCAA-TPN can maintain a patient's visceral protein better than standard TPN. Only two patients expired because of graft rejection and sepsis; their body weights and nutrition status showed deterioration despite aggressive nutrition support. CONCLUSIONS: We conclude that the nutrition support for patients with BMT is related to the success of marrow transplantation. Parenteral nutrition support, especially with TPN, is important because of frequent gastrointestinal dysfunction during the posttransplantational period, and it is better at maintaining the nutrition status and body weights of patients after BMT. An oral diet can be resumed after the patient's gastrointestinal function has improved and it can be tolerated.     

Immediate stimulation of protein metabolism in burned rats by total parenteral nutrition enriched in branched-chain amino acids

The effects of two kinds of total parenteral nutrition (TPN) on energy and protein metabolism were examined in rats subjected to 15% full-thickness scald burns in the absence of septic complications. One type of TPN was enriched in branched-chain amino acids (BCAAs), especially leucine (45% BCAA content), and the other was conventional TPN (21% BCAA content). Burned rats received isocaloric and isonitrogeneous TPN solutions for 48 hr after resuscitation by saline infusion for 24 hr. Liver and rectus abdominis muscle were removed from the rats at 7, 24, 48, and 72 hr. The concentrations of adenine nucleotides, RNA, protein, glucose-6-phosphate, hepatic glycogen, muscle phosphocreatine, and 3-methylhistidine were determined. Metabolic alterations occurred during the period of saline resuscitation (0-24 hr). At 48 hr the RNA and protein levels were significantly more improved in the BCAA-TPN group than in the conventional TPN group. At 72 hr, however, the results for the two groups were similar in most metabolite levels. Thus, BCAA-TPN enriched in leucine rapidly stimulated protein synthesis in the liver and muscle. This rapid effect may make it useful during the initial nutritional management of severe trauma patients.     

Metabolic effects of branched chain amino acids in patients with severe pancreatitis

Twenty-four patients with acute severe pancreatitis were randomised to receive total parenteral nutrition for 7 days with one of two isocaloric (35 kcal/kg/day) and isonitrogenous (0.16 g/kg/day) programmes containing either a low (15.5% w/w (control group)) or a high (57%) content of branched chain amino acids (BCAA (BCAA group)). During treatment, the nitrogen balance was similar in both groups. The concentrations of serum protein, albumin, prealbumin and retinol-binding protein did not differ between the groups. The plasma concentrations of BCAA measured 2 h after discontinuation of amino acid infusions rose in the BCAA group. In urine, only the concentrations of valine increased as compared with those of control patients. Serum glucose levels were higher in the BCAA group than in the control group, although the BCAA group received slightly more insulin than the control group in order to keep the blood glucose concentration below 10 mmol/l. The results suggest that BCAA-enriched solutions may stimulate gluconeogenesis without affecting catabolism.     

Postoperative parenteral nutrition with high supply of branched-chain amino acids: effects on nitrogen balance and liver protein synthesis

Branched-chain amino acids (BCAA) stimulate muscle and liver protein synthesis in vitro. The significance of this action in catabolic conditions in vivo remains controversial. The effects of a high supply of BCAA in total parenteral nutrition (TPN) on nitrogen balance and liver protein synthesis were studied in a postoperative rat model. After standard operative trauma TPN was commenced with one of two isocaloric programs (I: 20.1% BCAA and II: 50% BCAA) and continued for 48 hr. The relative rate of liver protein synthesis, measured after TPN in vitro by perfusion with 14C-leucine, was similar in both groups (I: 53.4 +/- 17.3 and II: 49.0 +/- 27.3 arbitrary units of synthesis rate, mean +/- SD). The cumulative nitrogen balance was positive with both regimens and was not improved by the high supply of BCAA (I: 2.02 +/- 0.81 and II: 1.87 +/- 0.63 gN/kg/48 hr mean +/- SD). We conclude that after moderate surgical trauma TPN with a high supply of BCAA offers no advantage over conventional TPN.     

Metabolic effect of parenteral nutrition in dogs with obstructive jaundice.

To assess the effect of total parenteral nutrition (TPN) on macronutrient metabolism in obstructive jaundice.

Forty adult mongrel dogs were equally divided into four groups: group I (PO-control) received sham ligation of common bile duct (CBDL) and was fed dog chow and water ad libitum; group II (PO-CBDL) underwent CBDL and was fed dog chow; group III (TPN-control) received sham CBDL and TPN; and group IV (TPN-CBDL) underwent CBDL and received TPN. Blood chemistries, plasma amino acids and liver histologies were studied before (Day 1) and at the end (Day 14) of the experiment.

A significant elevation of bilirubin and alkaline phosphatase was observed in dogs with CBDL. Blood glucose was not changed significantly in any group. Significant increases in triglyceride and cholesterol were present in CBDL dogs. Significant differences in the concentrations of a few plasma amino acids, including an elevation of phenylalanine, were found in TPN dogs. A significant increase in aromatic amino acids (AAA) and a noticeable depression of the molar ratio of branched-chain amino acids (BCAA) to AAA was present in TPN-CBDL dogs, as was a significant increase in blood ammonia.

In the presence of obstructive jaundice, TPN does not significantly affect carbohydrate or lipid metabolism. However, a derangement in protein metabolism with the standard TPN solution in current use suggests that either a modification of amino acid composition or an increase in total energy to protein energy ratio in TPN solution may be necessary to obviate such a consequence.     

Water-soluble vitamins in cancer patients on parenteral nutrition: a prospective study

Forty-three patients with mild weight loss were studied prospectively to determine whether the parenteral water-soluble vitamin doses in a commercially available preparation (MVI concentrate; USV Laboratories, Tarrytown, NY) maintained serum, red blood cell (RBC), and urinary concentrations of water-soluble vitamins in stressed cancer patients receiving total parenteral nutrition (TPN). Patients were divided into three groups: (1) oral diet, no intravenous vitamins given; (2) TPN plus 5 ml MVI; and (3) TPN plus 10 ml MVI. Vitamins C, B1, B2, B3, B6, and niacin were measured initially and weekly during a 6-week study period. Caloric and nitrogen balances were quantified. Most of the patients in all three groups had normal blood or urine levels of all water-soluble vitamins. No clinical evidence of vitamin deficiency or MVI toxicity was detected. The recommended parenteral dosages of vitamin C (100 mg/day) and B3 (15 mg/day) provided measurably adequate levels in all patients. Levels of vitamins B1, B2, B6, and niacin that were less than the normal range were noted in 4-40% of patients receiving the recommended daily dosages of 3 mg, 3.6 mg, 4 mg, and 40 mg, respectively. These deficiencies appeared to improve in group III patients who received twice the recommended parenteral vitamin dosages, although they did not completely disappear. Niacin deficiency appeared to be the most prevalent, occurring in 40% of patients studied. Since intravenous doses of B1, B2, B6, and niacin are safe and well tolerated, it appears that increased daily amounts of these vitamins should be given to cancer patients on parenteral nutrition.     

Aluminium loading in children receiving long-term parenteral nutrition

Eight children on long-term, total parenteral nutrition (TPN) were found to have elevated aluminium (Al) levels in plasma (51 +/- 11 mug 1 1 ), urine (223 +/- 78 mug 24 h) and bone. The load of Al in TPN solution was 232 +/- 89 mug/day, and, among the different parenteral solution components high Al concentrations were found in amino-acids, calcium gluconate, potassium lactate, and trace elements, representing respectively 40%, 30%, 15%, and 10% of the total Al intakes. The authors conclude that children receiving long-term TPN have excessive Al intakes and are exposed to Al toxicity. The prevention of Al contamination requires careful control of the TPN components.     

Total parenteral nutrition delays platelet engraftment in patients who undergo autologous hematopoietic stem cell transplantation

OBJECTIVES: One of the major challenges in the post-transplant period is nutrition. In this prospective, non-randomized study, total parenteral nutrition (TPN) was given to 31 patients and partial parenteral nutrition (PPN) was given to 30 patients undergoing autologous hematopoietic stem cell transplantation for solid tumors or hematologic malignancies to compare the effects of these parenteral nutrition modalities on post-transplant hematological engraftment, blood chemistry, and supportive therapy requirements. METHODS: All patients in the TPN group and 17 patients in the PPN group received growth factor in the post-transplant period. Both groups did not differ with respect to sex, age, and reinfused CD34(+) cell numbers. RESULTS: After transplantation body mass index and body weight decreased significantly in both groups (P < 0.001). Whereas serum albumin concentrations did not decrease significantly in the TPN group, it fell markedly in the PPN group at the end of parenteral nutrition (P = 0.019). After parenteral nutrition, blood chemistry was also remarkable for serum urea and glucose levels, which were elevated significantly in the TPN group (P < 0.001 and P = 0.03, respectively). Patients receiving TPN had a higher incidence of positive microbial cultures and clinical infection than did patients receiving PPN (64.5% versus 40%, P = 0.05). The most striking result was a delay in platelet engraftment for the TPN group compared with the PPN group (15.54 and 12.93 d, respectively; P = 0.014). This difference was also noted in patients using growth factor in the PPN group (P = 0.017). Parallel to these results, platelet transfusion requirement increased in the TPN group compared with the PPN group (1.93 versus 1.16 U, P = 0.004). Both groups were unremarkable for leukocyte recovery and red blood cell transfusion requirement. CONCLUSIONS: Consequently, TPN has some pitfalls of hyperglycemia, infection tendency, delayed platelet engraftment, and increased platelet transfusion requirement. Therefore, it should not be used as a standard nutrition support for patients undergoing autotransplantation.     

支链氨基酸强化的肠内肠外营养对肝硬化大鼠术后肝功能及血浆氨基酸谱的影响

目的探讨支链氨基酸（BCAA）强化的早期肠内肠外营养支持对肝硬化大鼠肝部分切除术后肝功能及血浆氨基酸谱的影响,为临床合理应用提供实验依据。方法将24只雄性SD肝硬化大鼠按编号法随机分为肠内营养组、肠内营养＋BCAA组和肠外营养＋BCAA组3组,3组大鼠行肝部分切除术后1d分别进行等热量等氮量营养支持,共5d。术后6d测定大鼠体重、肝功能、前白蛋白、转铁蛋白、肝组织白蛋白mRNA的表达、Ki67蛋白表达指数及进行血浆氨基酸谱分析。结果与术前比较,术后肠内营养、肠内营养＋BCAA、肠外营养＋BCAA组大鼠体重均减轻（P〈0．05）。术后肠外营养＋BCAA组较肠内营养组碱性磷酸酶水平升高（P〈0．05）;肠外营养＋BCAA组较肠内营养＋BCAA组血清天冬氨酸氨基转移酶、丙氨酸氨基转移酶、碱性磷酸酶水平升高（P〈0．05）。术后肠外营养＋BCAA组较肠内营养、肠内营养＋BCAA组血清前白蛋白水平降低（P〈0．05）,转铁蛋白差异无统计学意义（P〉0．05）。肠外营养＋BCAA、肠内营养＋BCAA组较肠内营养组血浆中亮氨酸、异亮氨酸明显升高,酪氨酸、苯丙氨酸、精氨酸、色氨酸明显降低（P〈0．05）;肠外营养＋BCAA组与肠内营养＋BCAA组比较,各氨基酸浓度差异均无统计学意义（P〉0．05）。肠外营养＋BCAA、肠内营养＋BCAA组较肠内营养组总氨基酸及芳香族氨基酸均降低,BCAA及BCAA／芳香族氨基酸比值升高（P〈0．05）。肠外营养＋BCAA组较肠内营养、肠内营养＋BCAA组肝组织白蛋白mRNA表达水平及Ki67蛋白表达指数均降低（P〈0．05）。结论BCAA强化的肠内肠外营养支持能改善肝硬化大鼠血浆氨基酸失衡,恢复血浆中BCAA／芳香族氨基酸比值;肠内营养在改善肝功能、促进肝脏蛋白质合成和肝硬化大鼠肝切除术后残肝肝再生方面优于肠外营养,但仍不能提高血浆白蛋白水平。     

Effects of cyclic (nocturnal) total parenteral nutrition and continuous enteral nutrition on circadian rhythms of blood lipids, lipoproteins and apolipoproteins in humans

The aim of the present study was to investigate the occurrence and characteristics (acrophase, amplitude) of circadian rhythms of serum total cholesterol, free-fatty acids (FFA), triglycerides, lipoproteins (HDL-, LDL-, and VLDL-cholesterol), apolipoproteins A and B, glucose and total proteins in hospitalized patients fed with 12 h nocturnal total parenteral nutrition (TPN) (from 8 PM to 8 AM) including lipids, patients fed with continuous enteral nutrition over 24 h daily spans, and patients eating 3 meals a day serving as controls. All the subjects were synchronized with diurnal activity and nocturnal rest in the hospital routine. The results showed the following: 1) circadian rhythms of total cholesterol, triglycerides, FFA, HDL-, LDL-cholesterol, apolipoprotein A and total proteins were detected in both TPN patients and controls, rhythms of apolipoprotein B and glucose in TPN patients only; in enteral nutrition patients, rhythms were detected for total proteins, glucose and triglycerides only; 2) a significant shift in triglyceride and FFA acrophases was observed in TPN patients, as compared with controls; 3) 24 h mean of both triglyceride and cholesterol concentrations remained unchanged after one month, in both TPN and enteral nutrition patients. The present approach, by extending results of previous investigations, leads one to conclude that, on both a metabolic and a chronobiological basis, cyclic nocturnal TPN is well-tolerated.     

Branched chain amino acid enriched parenteral nutrition in surgical intensive care patients

The metabolic responses to branched chain amino acid enriched total parenteral nutrition were studied in surgical intensive care patients with documented severe catabolism. Twenty-four patients were randomised to receive total parenteral nutrition with either 50% (BCAA) or 15% (Control) of its amino acid content as branched chain amino acids. The daily intake of nitrogen was 0.24 g per kg b. wt and that of energy, at steady state, 45 kcal per kg b. wt. Total parenteral nutrition resulted in similar nitrogen balances (Day 1 BCAA: -0.07 +/- 0.09, Control: -0.05 +/- 0.10; Day 4 BCAA: -0.12 +/- 0.07, Control: -0.06 +/- 0.09; Day 5 BCAA: -0.07 +/- 0.08, Control: -0.05 +/- 0.08 g/kg b. wt day; mean +/- S.D.) in both treatment groups throughout the study. The urinary excretion of 3-methylhistidine was higher before feeding in the control group but the rates were similar during total parenteral nutrition in both groups. There were no differences between the groups in the decrease of serum prealbumin during the study. We conclude that the proposed benefits, if any, from enriching nutritional regimens with branched chain amino acids are unlikely to be of major therapeutic relevance in severe catabolism.     

Nutritional support after liver transplantation: a randomized prospective study

Nutritional support in patients with advanced cirrhosis is difficult due to protein, fluid and salt restrictions. Successful liver transplantation should improve nutrient tolerance. We randomly assigned 28 hypoalbuminemic cirrhotic patients to receive, immediately after liver transplantation, one of three regimens: group 1, no nutritional support (n = 10); group 2, total parenteral nutrition (TPN) (35 kcal/kg/day) with standard amino acids (1.5 g/kg/day) (n = 8); or group 3, isocaloric isonitrogenous TPN with added branched-chain amino acids (n = 10). Therapy was continued for 7 days posttransplant. Jaundice resolution was unaffected by nutritional support. Nitrogen balance favored both TPN groups. Branched-chain amino acid (BCAA) aromatic amino acid ratios were highest in group 3. Coma scores and serum ammonia levels were similar in all groups. Both TPN groups achieved respirator independence earlier; this difference was not statistically significant. Group 1 patients stayed longest in ICU; the difference was statistically significant. TPN with either standard or BCAA- enriched amino acids is tolerated well immediately after successful liver transplant. Positive nitrogen balance is achieved; large protein loads do not worsen encephalopathy. Nutritional support may improve respiratory muscle function, allowing earlier weaning from ventilatory support. A shortened length of ICU stay justifies the expense of TPN.     

Parenteral nutrition of injured patients: Effect of manipulation of aminoacid infusion (increasing branched chain while decreasing aromatic and sulphurated aminoacids)

Sixteen critically ill injured patients received parenteral nutrition providing nitrogen (0.34 g kg(-1) day(-1)) and glucose (32 kcal kg(-1) day(-1)) for 5 days. They were randomly divided into two groups with respect to aminoacid supply: an essential aminoacid solution vs the same solution enriched in branched chain amino acid (BCAA) content and decreased in phenylalanine and methionine content (mean BCAA intake, 0.55 vs 0.69 g kg(-1) day(-1)). Basal values of nitrogen metabolism without treatment showed no difference between the two groups. Nitrogen losses and 3 methylhistidine (3-MEH) excretion were elevated; the plasma aminoacid pattern was altered by the trauma and except for phenylalanine, aspartate and glutamate, plasma aminoacid concentrations were decreased below normal values. Net muscular aminoacid output was demonstrated by femoral arterio-venous (av) differences that were all negative except for glutamate and citrulline TPN with both solutions improved the nitrogen balance and reduced the negative aminoacid balance across the leg. Adjusting a TPN regimen to increase the BCAA content without altering the total nitrogen infused, had no effect on overall nitrogen balance, but exerted a beneficial effect on body protein catabolism, as assessed by the urinary 3-MEH excretion rate, and a transient improvement in the aminoacid balance across the leg at the peak of the infusion. The short-lived effect of BCAA suggest a metabolic effect of these aminoacids which deserves further study.     

Clinical and metabolic effects of two lipid emulsions on the parenteral nutrition of septic patients

OBJECTIVE: We compared the metabolic and clinical effects of two lipid emulsions, long-chain triacylglycerols (LCT) and a mixture of medium- and long-chain triacylglycerols (MCT/LCT), in septic patients. METHODS: Both groups received total parenteral nutrition (TPN) with a solution enriched with branched-chain amino acids (BCAA). Seventy-two septic patients received TPN with MCT/LCT (group 1) or LCT (group 2). Before starting TPN (basal) and 10 d after (final), various parameters were evaluated. RESULTS: Twenty-six subjects in each group completed the study. Both groups showed an increase in cholestasis enzymes, with no significant changes in lipid parameters. The rise of retinol-binding protein and the recovery of nitrogen balance were significantly greater in group 1. A multivariate analysis of nutritional markers and catabolic parameters showed a better evolution in group 1 (P = 0.002). The MCT/LCT group exhibited a significant increase of insulin levels. Overall mortality and length of stay in the intensive care unit were not affected by the lipid emulsion. CONCLUSIONS: In septic patients who received TPN with a solution enriched with BCAAs, the use of an emulsion containing MCT provided them with a greater recovery of their nutrition status than the traditional LCT formula, without influencing the outcome.