Effect of age on substrate oxidation during total parenteral nutrition

OBJECTIVE: Parenteral nutrition is increasingly used in the elderly. Aging is accompanied by metabolic changes that can modify substrate use. We compared substrate oxidation during cyclic total parenteral nutrition (TPN) in elderly and middle-aged patients. METHODS: Twelve elderly patients (eight women, four men; 72 +/- 5 y) and 12 middle-aged patients (nine women, three men; 39 +/- 13 y) who were on cyclic TPN for intestinal failure were investigated while in stable condition after at least 15 d of TPN. No patient was diabetic. Indirect calorimetry was performed during fasting and every 30 min during the 3 h of TPN infusion and 3 h after infusion, allowing the measurement of nutrient oxidation. Blood samples were obtained every hour for the measurement of glucose, insulin, triacylglycerols, and free fatty acids. RESULTS: In the fasting state, resting energy expenditure was significantly higher in the elderly patients than in the middle-aged patients (39.3 +/- 8.1 versus 31.9 +/- 4.3 kcal/kg of fat-free mass per day, P = 0.008). During TPN, lipid oxidation was significantly higher in the elderly patients than in the middle-aged patients (1.09 +/- 0.17 versus 0.84 +/- 0.27 mg x kg(-1) x min(-1), P = 0.011); glucose oxidation was significantly lower in the elderly patients than in the middle-aged patients (2.19 +/- 0.93 versus 3.22 +/- 1.54 mg x kg(-1) x min(-1), P = 0.038). Areas under the curves of glycemia and free fatty acids were significantly higher in the elderly patients. CONCLUSION: In the elderly, TPN was associated with significantly higher lipid oxidation and lower glucose oxidation than in younger patients. TPN formulas and flow rates should therefore be adapted in the elderly.     

Comparison of the effects of continuous and cyclic nocturnal parenteral nutrition on energy expenditure and protein metabolism

Although cyclic nocturnal total parenteral nutrition is a widely used technique, its metabolic consequences have not been fully investigated. During two successive 7-day periods, 12 patients received randomly either standard continuous (infusion 24 hr/day) or cyclic (infusion between 5 pm and 9 am) total parenteral nutrition (TPN). Calorie and nitrogen intakes were identical during both periods. Energy expenditure was investigated by indirect calorimetry and showed practically no difference between continuous standard (1383 +/- 41 kcal/day-1) and cyclic total parenteral nutrition (1428 +/- 46 kcal/day-1). However, in the cyclic regimen, when compared with continuous infusion, energy expenditure was higher between 5 pm and 9 am and lower between 9 am and 5 pm. At the end of the noninfusion period, the 24-hr profile of the nonprotein respiratory quotient showed a slight decrease in patients receiving the cyclic infusion, in contrast with the stability of the quotient in the standard regimen. However, the nitrogen balance and variations in nutritional status did not differ significantly. In conclusion cyclic TPN is efficient for achieving a positive energy and nitrogen balance and in addition it induces a metabolic profile closer to physiological conditions.     

Long-term parenteral nutrition in unrestrained nonhuman primates: an experimental model

A freely mobile jacket and tether system was developed for the investigation of total parenteral nutrition (TPN)-induced metabolic bone disease and complications of prolonged TPN in 12 Macaca fascicularis nonhuman primates. The animals received TPN for 49 +/- 7 d (means +/- SEM), providing 82 +/- 2 kcal.kg-1.d-1. Serum glucose increased from 3.6 +/- 0.2 mmol/L at baseline to 8.3 +/- 1.9 mmol/L (p less than 0.01) during TPN, and serum albumin decreased from 38 +/- 1 g/L at baseline to 29 +/- 1 g/L (p less than 0.001) during 2.75% amino acid TPN and 30 +/- 2 g/L (p less than 0.01) during 5% amino acid TPN infusion. No significant changes were seen in serum prealbumin, total protein, bilirubin, alanine aminotransferase, and 5'-nucleotidase during TPN infusion. Major complications included catheter sepsis, hyperglycemia, diarrhea, and premature death in six animals. Thus, metabolic complications of prolonged TPN support may be investigated in a freely mobile nonhuman primate.     

Parenteral nutrition in septic patients: effect of increasing nitrogen intake

Metabolic effects of increasing nitrogen intake during total parenteral nutrition (TPN) were studied in nine septic patients. The patients were given 5% dextrose (D5W) for 1 d. For the next 6 d they received total parenteral nutrition (TPN), at 1.35 times resting energy expenditure (REE), containing either 191 or 366 mg N/(kg.d) Non-protein calories were divided equally between glucose and lipid emulsion. Three patients were studied on both diets (n = 6 for each diet). On the high- but not the low-N diet were significant increases in protein oxidation, blood urea N, O2 consumption, and CO2 production. TPN normalized most plasma amino acid levels but intramuscular amino acids remained unchanged. Transient positive N balance occurred during days 1-3 on the high- but not the low-N intake; on days 5-6 N balance did not differ significantly from zero on either diet and the improvement (165 mg N/[kg.d]) was the same for both diets.     

Parenteral structured triglyceride emulsion improves nitrogen balance and is cleared faster from the blood in moderately catabolic patients

BACKGROUND: Most postoperative patients lose net protein mass, which reflects loss of muscle tissue and organ function. Perioperative parenteral nutrition may reduce the loss of protein, but in general, with conventional lipid emulsions a waste of protein still remains. METHODS: We compared the effects on nitrogen balance of an emulsion containing structured triglycerides, a new type of synthesized triglycerides, with an emulsion of a physical mixture of medium- and long-chain triglycerides as part of parenteral feeding in moderately catabolic patients. The first 5 days after placement of an aortic prosthesis patients received total parenteral nutrition (TPN) providing 0.2 g of nitrogen per kg body weight per day; energy requirement was calculated using Harris and Benedict's equation, adding 300 kcal per day for activity. Twelve patients were treated with the structured triglyceride emulsion and 13 patients with the emulsion of the physical mixture of medium- and long-chain triglycerides. The design was a randomized, double-blind parallel study. RESULTS: In the patients who completed the study, the mean cumulative nitrogen balance over the first 5 postoperative days was -8+/-2 g in 10 patients on the structured triglyceride emulsion and -21+/-4 g in 9 patients on the emulsion of the physical mixture of medium- and long-chain triglycerides; the mean difference was 13 g of nitrogen (95% confidence interval 4 to 22, p = .015) in favor of the structured triglyceride emulsion. On the first postoperative day serum triglyceride and plasma medium-chain free fatty acid levels increased less during infusion of the structured triglyceride emulsion than with the physical mixture emulsion. CONCLUSIONS: The parenteral structured triglyceride emulsion improves the nitrogen balance and is cleared faster from the blood, compared with the emulsion of the physical mixture of medium- and long-chain triglycerides, in moderately catabolic patients.     

Substrate efficacy in early nutrition support of critically ill multiple trauma victims.

The metabolic consequences of excessive nutrition support in patients have been increasingly recognized in recent years. Time-dependent optimal nutrition support is desired for an early and uncomplicated recovery after severe injury or illness. Metabolic effects of adding balanced amino acids to glucose infusion during total parenteral nutrition were investigated in 18 patients after major trauma (injury severity score 32 +/- 2). Two studies were conducted on each subject, one in the early "flow" phase of injury (40-60 hours postinjury) in the basal state without any dietary intake and then after 4 to 6 days of intravenous nutrition provided solely as glucose (24 +/- 2 kcal/kg per day, 80% resting energy expenditure, n = 8) or isocaloric glucose (28 +/- 3 kcal/kg per day) with amino acids (275 +/- 28 mg of nitrogen per kilogram per day, n = 10). Whole-body fuel substrate kinetics were studied for energy metabolism (indirect calorimetry), protein kinetics (primed-constant infusion of 15N glycine), and lipid mobilization (two-stage infusion of 10% glycerol). Injury-induced hypoaminoacidemia was equally modulated whether the glucose-based nutrition had amino acids or not. The negative nitrogen balance is reduced similarly in both groups. Protein breakdown rate is significantly (p = .025) decreased in both groups and it is more so (30% vs 18%) in patients receiving total parenteral nutrition. Intravenous nutrition could not stimulate protein synthesis. Whole-body lipolysis rate as well as net fat oxidation rate are suppressed more when glucose alone is given, and this also results in less reesterification. Provision of intravenous glucose alone, not to exceed the resting energy expenditure, seems to be superior to isocaloric glucose with amino acids during this early catabolic flow phase of injury because the injured body could not assimilate this exogenous amino acid.     

Prevention of total parenteral nutrition-induced cholestasis by low non-protein energy supply: an animal experiment and clinical study

30 cecum-ligated rats were divided into 3 groups: group OS fed with stock diet; group HTPN (high-energy total parenteral nutrition) infused with 260 kcal/kg/d of non-protein energy (NPE), which was isoenergetic to the first group; and group LTPN (low-energy total parenteral nutrition) infused with 160 kcal/kg/d. All rats received approximately 1.4 g/kg/d of nitrogen. Positive nitrogen balances were obtained in all 3 groups, although the values were lower in group LTPN. Serum albumin remained normal. Total bilirubin, lipoprotein-X, alkaline phosphatase (AKP), gamma-glutamyl trans-peptidase (gamma-GT) and glutamic-pyruvic transminase (GPT) were significantly lower in group LTPN than in group HTPN. Histological examination with both light and electron microscopy revealed more severe bile stasis in the canaliculi in group HTPN than in group LTPN. In a separate clinical study, lasting more than 4 weeks, two groups of surgical patients received isonitrogenous TPN regimes containing different amounts of energy (40 kcal/kg/d and 30 kcal/kg/d, respectively). 40% of the NPE was infused as fat. The patients were matched for age, clinical condition and nutritional support technique. There were no differences between the groups in nitrogen balance or serum albumin. However serum AKP and gamma-GT increased in the HTPN group after 2 weeks of nutritional support, whilst in the LTPN group the increase did not occur until the fourth week. Our results suggest that TPN-induced cholestasis can be prevented or delayed by reducing the intake of NPE.     

Glutamine-enriched total parenteral nutrition in patients with inflammatory bowel disease

BACKGROUND: Studies in animal models of inflammatory bowel disease (IBD) suggest that supplementation of total parenteral nutrition with glutamine (gln), a conditionally essential amino acid in catabolic conditions, increases gln plasma concentrations, reduces intestinal damage, improves nitrogen balance and may improve the course of the disease. However, human data supporting this assumption are missing. METHODS: A total of 24 consecutive patients with an acute exacerbation of IBD (19 Crohn's disease; five ulcerative colitis) and scheduled for total parenteral nutrition (TPN) (>7 days) were randomised. Parallel to a standardised anti-inflammatory therapy, the patients received either a TPN with 1.5 g/kg body weight of a standard amino acid or an isonitrogenic, isocaloric TPN with 1.2 g/kg body weight of a standard amino acid and 0.3 g/kg L-alanine-L-glutamine. Primary end points were gln plasma concentrations and intestinal permeability assessed by urinary lactulose and D-xylose ratio. RESULTS: Gln plasma levels did not differ significantly in either group throughout the study. Intestinal permeability did not change within 7 days either with or without gln supplementation (Delta-lactulose/xylose ratio: 0.01+/-0.05 (gln+) vs 0.02+/-0.1 (gln-)). The observed changes in inflammatory and nutritional parameters, and also disease activity, length of TPN and hospital stay, were independent of glutamine substitution. Five (41%) patients in the gln+ group and three (25%) patients in the gln- group needed surgical intervention. CONCLUSION: Although limited by the sample size, these results do not support the hypothesis that glutamine substitution has an obvious biochemical or clinical benefit in patients with active IBD scheduled for total parenteral nutrition.     

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.     

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.     

Reducing parenteral energy and protein intake improves metabolic homeostasis after bone marrow transplantation

The purpose of this prospective study was to compare the metabolic effects of reducing parenteral energy and protein intake in bone-marrow-transplant (BMT) patients from 150% (hi-TPN group) to 100% (lo-TPN group) basal energy expenditure. Cytotoxic therapy was given on days 1-5, BMT on day 6, and TPN beginning on days 6 or 7. The lo-TPN group exhibited higher serum albumin (38 +/- 0.4 vs 32 +/- 0.4 g/L, P less than 0.01) but similar nitrogen balance (-83 +/- 8 vs -86 +/- 8 mg.kg-1.d-1, P greater than 0.05). Serum Na+ remained greater than 134 +/- 1 mmol/L in the lo-TPN group but fell to 127 +/- 1 mmol/L in the hi-TPN group (P less than 0.001) despite similar Na+ intakes and balances. Serum K+ remained less than 4.4 +/- 0.2 mmol/L in the lo-TPN group but rose to 5.1 +/- 0.1 mmol/L in the hi-TPN group (P less than 0.01) despite similar K+ intakes and balances. Delivering TPN at lower-than-normal rates after BMT appears to minimize Na+ and K+ disturbances and improve serum albumin concentrations without having any adverse effect on nitrogen balance.     

Safety and metabolic tolerance of a concentrated long-chain triglyceride lipid emulsion in critically ill septic and trauma patients

BACKGROUND: A concentrated fat emulsion (Intralipid 30%) with a phospholipid/triglyceride ratio of 0.04 was tested for clinical tolerance and metabolic effects in the short-term parenteral nutrition of septic and trauma critically ill patients and compared with Intralipid 20% (phospholipid/triglyceride ratio of 0.06). METHODS: This was a prospective, randomized, multicenter study in the intensive care units in 10 university hospitals, including 90 adult patients in 2 groups: 55 septic and 35 trauma patients. Patients in each group were randomly divided into 2 subgroups according to the fat emulsions administered (1.4 g/kg per day) as part of the calories for at least 6 days of continuous total parenteral nutrition (TPN). One subgroup was treated with 30% long-chain triglycerides (phospholipid/ triglyceride ratio: 0.04) and the other with 20% long-chain triglycerides (phospholipid/triglyceride ratio: 0.06). The parenteral nutrition formula was isocaloric and isonitrogenous with 0.25 g of nitrogen/kg per day and 40% of the nonprotein calories as fat. Clinical tolerance was assessed during the study. At baseline and after 3 and 6 days of TPN, the following biochemical parameters were measured: prealbumin, retinol-binding protein, serum albumin, hematologic, hepatic and renal function variables, triglycerides, phospholipids, total and free cholesterol, nonesterified cholesterol, nonesterified fatty acids, and lipoproteins. RESULTS: At baseline, no differences in age, gender, severity of the condition [Acute Physiology and Chronic Health Evaluation (APACHE II) score], or clinical chemistry were found between the subgroups. The levels of plasma proteins studied and the renal, hematologic, or hepatic function variables did not vary during the study period. Total cholesterol increased significantly, owing to esterified cholesterol, with 20% long-chain triglyceride in septic patients (baseline: 2.1 +/- 0.8 mmol/L, day 6: 2.8 +/- 0.6 mmol/L, p = .026). In septic patients receiving 20% long-chain triglycerides, plasma triglycerides had a similar behavior (baseline: 1.4 +/- 0.6 mmol/L, day 3: 2.2 +/- 0.8 mmol/L, p < .05). The very-low-density lipoprotein content of cholesterol, triglycerides, and phospholipids showed a tendency to decrease in septic patients treated with 30% long-chain triglycerides (NS). None of the emulsions induced the synthesis of lipoprotein X. CONCLUSIONS: Our results indicate that while both fat emulsions used in the TPN of critically ill patients are clinically safe, the 30% long-chain triglyceride fat emulsion with a phospholipid/triglyceride ratio of 0.04 causes fewer lipid metabolic disturbances.     

Acetate and hypercalciuria during total parenteral nutrition

Hypercalciuria and negative calcium balance are complications of total parenteral nutrition (TPN). Because metabolism of the TPN formula generates an acid load that can induce hypercalciuria, we evaluated the effect of supplementing the formula with acetate. In a randomized crossover study six patients on continuous and six on cyclic TPN received no added acetate or 160 mmol acetate/d replacing 160 mmol chloride/d for 3 d each. Blood and urine measurements were obtained on day 3 of each formula. Acetate, which is metabolized to bicarbonate, increased blood pH and decreased renal acid excretion. Urinary Ca decreased in every patient from 422 +/- 63 to 240 +/- 46 mg/d (10.5 +/- 1.6 to 6.0 +/- 1.4 mmol/d) and from 468 +/- 68 to 285 +/- 54 mg/d (11.7 +/- 1.7 to 7.1 +/- 1.3 mmol/d) during continuous and cyclic TPN, respectively. Filtered Ca load decreased slightly whereas renal tubular Ca reabsorption increased significantly with acetate. Serum parathyroid hormone, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D, and urinary cyclic AMP were not different.     

Molybdenum requirements in low-birth-weight infants receiving parenteral and enteral nutrition.

BACKGROUND: Molybdenum (Mo) is an essential trace element required by three enzymatic systems, yet there are no reports of Mo deficiency in infants. Low-birth-weight infants (LBW) might be at risk for Mo deficiency because they are born before adequate stores for Mo can be acquired, they have rapid growth requiring increased intakes, and they frequently receive supplemental parenteral nutrition (SPN) and total parenteral nutrition (TPN) unsupplemented with molybdenum. METHODS: To investigate Mo requirements of LBW infants (n = 16; birth weight, 1336+/-351 g; gestational age, 29.8+/-2.5 weeks; M+/-SD), the authors collected all feeds, urine, and feces prior to TPN (baseline, n = 16, collections = 16), during TPN (n = 9, collections = 19), during SPN (n = 13, collections = 17), and after one week of full oral feeds (FOFs) of formula or human milk (FOF, n = 16, collections = 16). RESULTS: Infant weights at collection times were: 1.3+/-0.3 g, 1.27+/-0.4 g, 1.4+/-0.3 g, and 1.7+/-0.5 g, respectively. Mo intake was 0.03+/-0.1 microg/d, 0.34+/-0.1 microg/d, 1.25+/-1.7 microg/d, and 6.1+/-2.5 microg/d. Mo output was 0.64+/-0.6, 0.34+/-0.5, 0.68+/-0.8, and 4.1+/-2.5 microg/d. Mo balance at these times was -0.60+/-0.5, -0.001+/-0.5, 0.57+/-1.9, and 2.0+/-2.9 microg/d. Mo balance increased with time, yet some infants were always in negative balance, even though Mo intakes exceeded recommendations. CONCLUSIONS: The authors speculate that an intravenous intake of 1 microg/kg/d (10 nmol/kg/d) and an oral intake of 4-6 microg/kg/d (40-60 nmol/kg/d) would be adequate for the LBW infant.     

Protein metabolism assessed by 1-13C leucine infusions in patients undergoing bone marrow transplantation

Patients receiving cytoreductive therapy and bone marrow transplantation (BMT) are known to develop marked protein catabolism. To assess the contribution of whole body protein breakdown, amino acid oxidation and incorporation into proteins, plasma leucine kinetics (1-13C-leucine infusion technique) were determined in six patients five times within 14 days before and after cytoreductive therapy (Cyclophosphamide and total body irradiation) and marrow transplantation. Nitrogen balance became negative (-0.20 +/- 0.04 g/Kg/24 hr) after cyclophosphamide (p less than 0.01) and was -0.25 +/- 0.05 g/Kg/24 hr 7 days after BMT in spite of total parenteral nutrition. Plasma leucine concentration increased after BMT by 67% (p less than 0.0015). Leucine plasma appearance was 1.20 +/- 0.15 mumol/kg/min before treatment, it increased slightly and transiently after cyclophosphamide, and increased again from day 5 to day 7 after BMT (p less than 0.01), suggesting increased protein break-down. Leucine oxidation increased from 0.27 +/- 0.07 before therapy to 0.97 +/- 0.16 mumol/kg/min (p less than 0.02) after cyclophosphamide and BMT. Nonoxidative leucine disappearance rate decreased slightly from 0.92 +/- 0.08 to 0.75 +/- 0.16 mumol/kg/min after BMT (ns). Leucine metabolic clearance rate decreased from 11.8 +/- 1.65 before therapy to 6.9 +/- 0.70 ml/kg/min (p less than 0.02) after cytoreductive therapy. After BMT it increased again to 9.9 +/- 1.5 ml/kg/min (p less than 0.02). The results demonstrate that patients undergoing cytoreductive therapy and bone marrow transplantation develop negative nitrogen balance due to increased protein breakdown associated with increased leucine oxidation and increased metabolic clearance rate.(ABSTRACT TRUNCATED AT 250 WORDS)     

Net protein anabolism with hypocaloric parenteral nutrition in obese stressed patients

Thirteen obese patients requiring parenteral nutrition for postoperative complications were studied prospectively to evaluate the efficacy of hypocaloric, high-protein parenteral feeding. Nonprotein caloric intake averaged 881 kcal/d or 51.5% of the patients' measured resting energy expenditure. Protein intake averaged 2.13 +/- 0.59 g/kg IBW. Serum albumin and TIBC increased significantly (2.8 +/- 0.5 g/dL to 3.2 +/- 0.4 g/dL, p less than 0.01, and 196 +/- 39 micrograms/dL to 248 +/- 49 micrograms/dL, p less than 0.05, respectively), and subjects lost weight (120.0 +/- 60.0 kg to 109.7 +/- 32.5 kg, p less than 0.05). Nitrogen balance studies in eight subjects suggested nitrogen equilibrium or positive balance can be achieved (+2.4 +/- 1.9 g/d). All patients exhibited complete tissue healing of wounds and abscess cavities and closure of fistulae. In obese, protein-depleted surgical patients net protein anabolism and clinical efficacy can be achieved with hypocaloric, high-protein feeding. Abundant endogenous fat stores provide obligatory energy.     

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.     

Influence of stress, depletion, and/or malignant disease on the responsiveness of surgical patients to total parenteral nutrition

We performed a series of 14C[urea] infusions to assess the effect of depletion (greater than 15% decrease in body weight), stress (VO2 greater than 130 mumol.kg-1.min-1), and cancer on the basal rate of net protein catabolism (NPC) and the response of patients to total parenteral nutrition (TPN). Depleted patients had low rates of NPC (0.8 +/- 0.1 g.kg-1.d-1) compared with nondepleted patients (p less than 0.05) and during TPN anabolism was achieved (0.5 +/- 0.2 g.kg-1.d-1). Gastrointestinal (GI) cancer patients had rates of NPC similar to those of normal volunteers; during TPN, NPC approximated zero. Severely stressed (SS) nondepleted patients had high rates of NPC (2.7 +/- 0.2 g.k-1.d-1) whereas SS-depleted patients had lower (p less than 0.05) rates of NPC (1.9 +/- 0.3 g.kg-1.d-1); both groups of SS patients remained catabolic despite TPN (1.2 +/- 0.3 and 0.5 +/- 0.2 g.kg-1.d-1, respectively). In response to TPN, depleted patients become anabolic, GI cancer patients stop losing protein but do not become anabolic, and stressed patients remain catabolic and continue to loss protein.