Impact of enteral and parenteral nutrition on hepatic and muscle glucose metabolism

Liver and muscle metabolism were assessed in dogs adapted to long-term total parenteral (TPN) and enteral (TEN) nutrition. Studies were done in 13 conscious long-term catheterized dogs in which sampling (artery, portal and hepatic vein, and iliac vein), infusion catheters (inferior vena cava, duodenum), and transonic flow probes (hepatic artery, portal vein, and iliac artery) were implanted. Fourteen days after surgery dogs were grouped to receive TPN or TEN. After 5 days of TPN/TEN, substrate balances across the liver and limb were assessed. The liver was a marked net consumer of glucose in both groups (23.6 +/- 3.3 vs 22.6 +/- 2.8 micromol x kg(-1) x min(-1), TPN vs TEN) despite near normoglycemia (6.5 +/- 0.3 vs 6.7 +/- 0.2 mmol/L). Arterial insulin levels were higher during TEN (96 +/- 6 vs 144 +/- 30 pmol/L; p < .05). The majority (79 +/- 13 vs 76% +/- 7%) of the glucose taken up by the liver was released as lactate. Despite higher insulin levels during TEN the nonsplanchnic tissues consumed a lessor quantity of glucose (25.9 +/- 3.3 vs 16.1 +/- 3.9 micro x mol x kg(-1) x min(-1)). In summary, the liver undergoes a profound adaptation to TPN and TEN making it a major site of glucose uptake and conversion to lactate irrespective of the route of nutrient delivery. However, the insulin requirements are higher with TEN possibly secondary to impaired peripheral glucose removal.     

Intralipid-based short-term total parenteral nutrition does not impair small intestinal mucosa-related cellular immune reactivity in the healthy rat

BACKGROUND: The lipid component of total parenteral nutrition (TPN) has reportedly been associated with trophic effects on the intestinal mucosa and suppressive effects on the immune system. METHODS: We have challenged these hypotheses using a 7-day TPN rodent model comparing the effects of isocaloric, isonitrogenous lipid-based (TPN-lipid, 50% of calories as long-chain triacylglycerol) and carbohydrate-based TPN (TPN-CH, 100% of calories as carbohydrates) on mucosal morphology and immune function. Enterally fed animals were included to establish a baseline for immunologic read-outs. The study was performed in healthy, metabolically stable animals to avoid interference by septic or trauma-related stress factors. RESULTS: Both TPN regimens resulted in a significantly smaller weight gain (TPN-lipid, 29.8 +/- 4.0 g; TPN-CH, 30.3 +/- 4.4 g) compared with enterally fed reference animals (49.2 +/- 3.2 g; p = .007), with no difference in nitrogen balance between the TPN groups. Mucosal sucrase activity was significantly lower in both TPN groups (TPN-lipid, 8.8 +/- 1.0 x 10(-7) katal per gram (kat/g) of protein; CH: 11.9 +/- 1.6 x 10(-7) kat/g of protein) compared with enteral feeding (17.4 +/- 0.9 x 10(-7) kat/g of protein; ANOVA: p = .0007). Morphometric analysis of the small intestine revealed no differences between the two TPN groups although a significantly depressed villus height in the TPN-lipid group could be observed in comparison to enterally fed reference rats (TPN-lipid, 0.47 +/- 0.02; TPN-CH, 0.50 +/- 0.01; enteral, 0.56 +/- 0.02 mm; ANOVA: p = .0298). Light and electron microscopy revealed a normal surface architecture in all three groups of rats. Cellular immune reactivity was evaluated using a novel specific immunization protocol: animals were immunized against OVA 4 weeks before TPN. OVA-induced lymphoproliferative responses and phenotypic data from draining popliteal and mesenteric lymph nodes were evaluated after the different regimens. Results did not differ among the three groups. CONCLUSIONS: In healthy rodents, short-term lipid-based and carbohydrate-based TPN regimens lead to limited mucosal atrophy with preserved surface architecture compared with enteral feeding. However, peripheral and mesenteric cellular immune responsiveness after both TPN regimens remained comparable to enterally fed reference animals. Therefore, mesenteric and systemic cellular immune reactivity does not appear to be impaired by lipid-based or carbohydrate-based TPN.     

Metabolic and thermogenic response to continuous and cyclic total parenteral nutrition in traumatised and infected patients

16 traumatised or infected patients on mechanical ventilation were randomised to continuous TPN or to cyclic TPN after a 24-h period of glucose infusion (1.25 kJ x kg BW(-1) x h(-1)). Energy supply was equivalent to 1.3 x baseline energy expenditure. Glucose, fat and amino acids were administered at a constant rate over 24 h in the continuous TPN group and over 12 h, followed by glucose (1.25 kJ x kg BW(-1) x h(-1)), in the cyclic TPN group. Nutrient-induced thermogenesis was lower during continuous than during cyclic TPN (5 +/- 4 vs. 12 +/- 7%, mean +/- SD, p < 0.05), as was the increase in CO(2) elimination (13 +/- 11 vs. 30 +/- 7%, respectively, p < 0.01). Energy balance was more positive during continuous TPN. In both groups, energy expenditure reached a plateau during the first 12 h of TPN infusion. The lower nutrient-induced thermogenesis and more positive energy balance, indicates a more efficient utilisation of nutrients during continuous than during cyclic TPN. The lower CO(2) production during continuous TPN, may be advantageous when respiratory function is compromised. The plateau in energy expenditure in response to TPN infusion may be useful as a guideline for nutritional therapy.     

肠内营养对肝功能受损病人术后肠粘膜屏障的影响

目的：探讨严重肝功能损伤的病人术后施行肠内营养（EN）支持对胃肠道粘膜屏障的保护作用及临床意义。方法：将肝功能为ChildB级的成年病人共76例，随机分为肠内营养组（EN，n=30)、全肠外营养组（TPN，n=26)和对照组（CON，n=20)，分别检测三组病人术前1天，术后5天和10天时的营养状况及肝功能的变化，并检测尿中排泄的乳果糖（L）和甘露醇（M）的比值（L／M），观察不同营养方法对肠粘膜通透性的影响。结果：EN组和TPN组病人术后都无明显肝功能害加重的表现；EN组病人术后较早达到正氮平衡，体重减轻功较少，与TPN组相比差异显著（P＜0．05）；EN组病人手术前，后L／M值无明显变化（P＞0．05），而TPN组和CON组变化明显（P＜0．05）。结论：对肝功能严重受损的病人，EN是一种方便、安全、有效的临床营养支持方法；EN对肠道粘膜屏障具有明显的保护作用。     

Effects of fat emulsions with different fatty acid composition on plasma and hepatic lipids in rats receiving total parenteral nutrition

Effects of different fatty acids on the development of hepatic steatosis were studied in rats receiving total parenteral nutrition (TPN). 65 rats, with internal jugular catheters, were divided into one control group (n = 8), and four experimental groups (n = 13-15 each). The control group was fed a chow diet and all experimental groups received TPN. TPN provided 300 kcal/kg/day with 40% of the non-protein energy provided as fat. All TPN solutions were isonitrogenous and identical in nutrient composition except for the fatty acid composition of the fat emulsion. Four kinds of fat emulsions rich in: 1) medium chain fatty acids (C8:0,C10:0), 2) oleic acid (C18:1 n-9), 3) linoleic acid (C18:2 n-6), 4) eicosapentaenoic acid (C20:5 n-3)/docosahexaenoic acid (C22:6 n-3), were used. These fat emulsions were prepared with: 1) a mixture of medium chain triglycerides (MCT) and soybean oil (9:1), 2) olive oil, 3) safflower oil, 4) fish oil, respectively. The results of the study demonstrated a higher hepatic lipid content in the olive oil and safflower oil groups than in the control group, whereas no significant difference was seen between the MCT and control groups. Also, no difference was observed between the fish oil and control groups. With regard to the plasma lipids, the MCT group and olive oil group produced hyperlipidaemia. The plasma of the safflower oil and fish oil groups, however, had a low lipid concentration comparable to the control group. These results suggest that TPN with a fat emulsion prepared with fish oil does not cause hyperlipidaemia nor induce hepatic steatosis in normal rats.     

Evaluation of nonglucose carbohydrates in parenteral nutrition for diabetic patients.

OBJECTIVE: There is little information on the advantages of nonglucose carbohydrates in total parenteral nutrition (TPN) for diabetic patients. The aim of this study is to evaluate glycemic control and insulin requirements in diabetic patients who received TPN with different sources of carbohydrates, and to determine whether insulin requirements are different when septic and non-septic diabetic patients are studied. MATERIALS AND METHODS: One-hundred and thirty-eight patients were randomly divided into two groups receiving either glucose (G), n=71, or glucose-fructose-xylitol 2:1:1 (GFX), n=67. There were no differences between the demographic or anthropometric characteristics of the groups, nor between the patients with diabetes mellitus type 1 and type 2, nor the initial TPN composition. Acceptable glycemic control was considered when glycemia reached <200 mg/dl. RESULTS: Glycemic control was attained in 79.7% of patients (74.6 vs 85.1%), in the same period of treatment. At the end of treatment, insulin requirements were not different (45+/-19 vs 45+/-26 UI/day) in both groups, while similar amounts of carbohydrates (191+/-36 vs 187+/-45 g/day) were infused. The ratio insulin/body weight and insulin/carbohydrates were equal in both groups. In the GFX group nonseptic and septic patients needed less and more insulin, respectively, than their counterparts in the G group. No major adverse events related to carbohydrate infusions were observed. CONCLUSIONS: Either G or GFX could be used in TPN for diabetic patients, providing glycemic control in most cases with similar insulin requirements. GFX mixtures were slightly more beneficial to attain glycemic control in nonseptic patients, but septic diabetic patients had higher insulin needs in this group.     

Hypocaloric enteral tube feeding in critically ill obese patients

OBJECTIVE: We respectively compared the nutritional and clinical efficacies of eucaloric and hypocaloric enteral feedings in 40 critically ill, obese patients admitted to the trauma or surgical intensive care unit. METHODS: Adult patients, 18 to 69 years old, with weights greater than 125% of ideal body weight, normal renal and hepatic functions, and who received at least 7 d of enteral tube feeding were studied. Patients were stratified according to feeding group: eucaloric feeding (>or=20 kcal/kg of adjusted weight per day; n = 12) or hypocaloric feeding (<20 kcal/kg of adjusted weight per day; n = 28). The goal protein intake for both groups was approximately 2 g/kg of ideal body weight per day. Clinical events and nutrition data were recorded for 4 wk. RESULTS: Patients were similar according to sex, age, weight, body mass index, Second Acute Physiology and Chronic Health Evaluation score, Trauma score, and Injury Severity Score. The hypocaloric feeding group received significantly fewer calories than the eucaloric group (P相似文献   

消化道肿瘤-T-术后早期肠内营养疗效研究

目的评价消化道肿瘤手术后早期肠内营养的安全性,比较手术后短期应用要素制剂爱伦多的肠内营养与标准肠外营养支持的疗效。 方法62例消化道恶性肿瘤手术患者,随机分为对照组、肠外营养组和肠内营养组。手术后第一天开始等热卡、等氮量的肠外或肠内营养支持一周。检测体重、机体测量指标、血浆各内脏蛋白浓度及氮平衡等营养指标,外周血T细胞亚群、NK细胞和NK细胞活性等免疫指标及血清氨基酸谱。 结果三组病人术后体重下降分别为4．26±1．03ks、2．04±0．65ke和2．12±o．72kg,对照组与肠外营养组、肠内营养组之间差异有显著性(P<0．05),后两组之间无差异。术后各内脏蛋白浓度均低于术前,对照组降低最明显,与肠外或肠内营养组之间差异有显著性(P<0．05),而后两组之间无差异。三组病人平均氮平衡为—8．6±3．12g／d,—4．22±2．02g／d及—3．88±2．35g／d,对照组与肠外或肠内营养组之间差异有显著性(P<0．05),而后两组之间无差异。手术后各组病人外周血T细胞亚群、NK细胞和NK细胞活性均不同程度下降,但三组之间差异无显著性意义。三组病人血清谷氨酰胺水平明显下降,术后1周对照组和肠外营养组血清谷氨酰胺水平仍处于低水平,而肠内营养组却有一定程度恢复。 结论消化道肿瘤手术后早期肠内营养支持是安全、有效的方法,短期肠内营养和肠外营养支持的临床效果基本相同。     

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.     

Protein dynamics during refeeding of protein-depleted rats: effects of increasing amino acid intake by TPN or enteral continuous feeding

The effect of increasing nitrogen intake with constant calorie supply was studied in protein-depleted rats. Animals were randomized into three paired groups to receive either total parenteral nutrition (TPN) or enteral (EF) isocaloric feedings (240 kcal X kg-1 X day-1) differing only in their amount of amino acids. The diets, composed of dextrose, a safflower oil emulsion and crystalline amino acids, were infused continuously for 5 days. Daily nitrogen intakes were for controls (EF, n = 7; TPN, n = 6) 0.25 g/kg; for groups 1 (EF, n = 7; TPN, n = 8) 1.4 g/kg and for groups 2 (EF, n = 7; TPN, n = 7) 2.5 g/kg. The rats in groups 1 and 2 obtained significant protein repletion in terms of body weight, nitrogen retention, liver protein and serum albumin regardless of the route of nutrient delivery. However, rats in groups 2 (higher nitrogen intake) presented a more rapid and greater recovery despite a reduction in nitrogen utilization. Whole-body leucine kinetics studied at the end of controlled feeding periods were similar for EF and TPN rats. However, increasing nitrogen intake (1 and 2) increased whole-body leucine flux and incorporation into protein resulting in a better balance, since leucine release from protein breakdown was comparable to controls. Liver protein fractional synthetic rates were reduced in EF while remaining at a high rate in TPN group 2 and still more elevated in TPN group 1, suggesting a preferential support of liver protein by enteral feeding or the effect of TPN as a non-physiologic route.     

Modulating effects of the feeding route on stress response and endotoxin translocation in severely stressed patients receiving thoracic esophagectomy

Experimental studies have demonstrated that the route of nutritional supply impacts the systemic metabolic responses after surgical injury. Intestinal mucosal atrophy, as induced by total parenteral nutrition (TPN) or prolonged bowel rest, has been reported to enhance bowel endotoxin translocation. The operative procedure for thoracic esophageal cancer, including thoracotomy, laparotomy, and three-field lymph-node dissection, is a particularly stressful surgery that requires long-term aggressive nutritional support and often results in the postoperative hypermetabolic state, leading to perturbation of postoperative immune function. Interleukin-6 (IL-6) plays an important role in host inflammatory responses, whereas IL-10 is linked to suppression of cellular immunity. The aim of this study was to investigate how the antecedent nutritional routes influence systemic IL-6 and IL-10 responses and endotoxin translocation after an operation for thoracic esophageal cancer. Twenty-nine patients who underwent esophagectomy with three-field lymphadenectomy were investigated. They were assigned to groups receiving either TPN (n = 18) or enteral nutrition (EN; n = 11) providing 35 kcal x kg(-1) x d(-1) of energy and approximately 1.2-1.5 g x kg(-1) x d(-1) of amino acids. These nutritional supports were conducted from 1 wk before the operation to 14 d after the operation. Serum IL-6, IL-10, and endotoxin concentration were measured before and during the operation and at 2 h and 1, 3, and 7 d after the operation. IL-6 in sera was significantly higher after the operation in both groups. In the EN group, however, significantly less IL-6 production was observed on the third and seventh postoperative days when compared with those patients in the TPN group. Similarly, serum IL-10 concentration in the TPN group showed a significantly higher level than that in the EN group. Serum IL-6 showed a significant positive correlation with IL-10 at 2 h and at 7 d after the operation, suggesting that the reduced inflammatory responses were related to the inhibition of the development of postoperative immunosuppression. Endotoxin concentration in sera was significantly lower in the EN group after the operation than in the TPN group. Perioperative EN provides better regulation of inflammatory cytokine responses and may contribute less to immunosuppression after major surgery than parenteral nutrition. The attenuated production of endotoxin induced by EN may play an important role in these phenomena.     

Effect of c-reactive protein and interleukins blood levels in postsurgery arginine-enhanced enteral nutrition in head and neck cancer patients

OBJECTIVE: It is known that the immune system is frequently affected in patients with head and neck cancer. Although immune dysfunction could be multifactorial, this immune system may be modulated by specific nutritional substrates, such as arginine. The aim of our study was to evaluate the effect of enteral nutrition supplemented with arginine on c-reactive protein (CRP), interleukin 6 (IL-6) and tumour necrosis factor (TNFalpha) in surgical head and neck cancer patients. DESIGN: Randomized trial. SETTING: Tertiary care. SUBJECTS: A population of 36 patients with oral and laryngeal cancer were enrolled. INTERVENTIONS: At surgery patients were randomly allocated to two groups: (a) patients receiving an enteral diet supplements with arginine and dietary fibre (group I, n=18); (b) patients receiving an isocaloric, isonitrogenous enteral formula (group II, n=18). Perioperatively and on postoperative day 5 the following parameters were evaluated: serum values of prealbumin, transferrin, albumin, total number of lymphocytes, interleukin 6, tumour necrosis factor alpha and c-reactive protein. RESULTS: The mean age was 59.6+/-10.9 y (two females/34 males). No significant intergroup differences in the trend of the three plasma proteins and weight were detected. CRP decreased in both groups (group I: 152.9+/-76.9 vs 68.9+/-82.5 mg/dl; P<0.05; and group II: 105.9+/-92 vs 43.6+/-59.1 mg/dl; P<0.05). Interleukin 6 did not change (group I: 16.3+/-12.3 vs 35.6+/-83.4 pg/ml; NS; and group II: 22.8+/-40 vs 9.9+/-17.7 pg/ml; NS). TNFalpha did not show any differences (group I: 4.6+/-1.6 vs 5.1+/-1.5 pg/ml; NS; and group II: 8.8+/-6.1 vs 5.8+/-1.7 pg/ml; NS). Lymphocytes increased in both groups (group I: 1405.6+/-517 vs 1634+/-529 x 10(6)/ml; P<0.05; and group II: 1355+/-696 vs 1561+/-541 x 10(6)/ml; P<0.05). CONCLUSIONS: Enhanced formula did not change IL6 and TNFalpha levels. Further studies are needed to determine whether route of nutrition or type of formula is the key in these patients.     

Effect of structured lipids as energy substrate after hepatectomy in rats with streptozocin-induced diabetes.

The suitability of energy substrates for use by the remnant liver after 70% hepatectomy was studied in relation to the hepatic energy status in diabetic rats. Rats with streptozocin-induced diabetes underwent 70% hepatectomy and were divided into five groups receiving total parenteral nutrition (TPN) for 24 h. One group received standard TPN without fat, and four groups respectively received standard TPN with long-chain triglycerides (LCTs), medium-chain triglycerides (MCTs), mixed triglycerides (MIX), or structured lipids (SLs) as a 10% lipid emulsion. The latter groups received 60% of nonprotein calories per day with fat emulsion (LCT, MCT, MIX, or SL), and the remaining 40% with glucose. The group that received 100% of nonprotein calories per day with glucose was defined as the TPN group. All rats in the TPN group died from nonketotic hyperosmolarity within 24 h. The blood ketone body ratio (acetoacetate/beta-hydroxybutyrate), the energy charge level of the remnant liver, and the cumulative excretion of 14CO2 in expired breath during 6 h after [14C]glucose administration were all significantly higher in the SL group than in the other groups 24 h after hepatectomy. These findings suggest that SL may be a superior energy substrate to other triglyceride preparations during the immediate posthepatectomy phase in diabetic patients.     

Liver composition and histology in growing infant miniature pigs given different total parenteral nutrition fuel mixes

Although young infants are at greater risk for total parenteral nutrition (TPN)-related liver disease than adults, previous studies on the effect of the TPN energy source on the development of hepatic steatosis have been carried out in adult rats and adult humans. We studied the effect of a glucose and a glucose/fat TPN energy regimen on hepatic chemical composition and the development of steatosis in newborn miniature pigs. Twenty miniature pigs were randomized at 10 days of age to receive a TPN regimen which utilized either glucose (group A) or glucose/fat (group B) as the non-nitrogen energy source. After 8 days, blood was drawn for insulin, glucagon, SGPT, albumin, and bilirubin determinations. Samples of liver were obtained at 9 days. Plasma insulin levels were significantly higher and glucagon levels lower in group A piglets than in those in group B. Normal values were obtained for SGPT, albumin, and bilirubin, and no differences were found between groups. Chemical analysis of the livers revealed no differences between groups in the concentrations of glycogen, fat, protein, DNA, and RNA. Group A animals had significantly higher concentrations of water than group B (group A: 0.75 +/- 0.01 liter/kg; group B: 0.74 +/- 0.01; p less than 0.03). A significant correlation was found in group B between the plasma insulin/glucagon ratio and the hepatic glycogen concentration (r = 0.73, p less than 0.05). Group A animals had fat vacuoles in centrilobular hepatocytes, in contrast with group B animals who had visible fat only in Kupffer cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of different intravenous feeding regimens on the rates of synthesis of alpha1-antitrypsin after surgery

The effects of two nutritional regimens on the synthesis of alpha-1 antitrypsin were investigated postoperatively in gynaecological cancer patients. Total parenteral nutrition (TPN) or a hypocaloric amino acid mixture was administered on the day of surgery and continued for 3 days. The rate of synthesis of alpha-1 antitrypsin was estimated by a computer model from serial plasma concentrations of this protein and a reference protein, albumin. The hypocaloric amino acid mixture resulted in a more negative nitrogen balance than that produced during administration of TPN containing the same amount of nitrogen but more non-protein energy. Urinary excretion of 3-methylhistidine was significantly greater (p = 0.017) in the hypocaloric amino acid group (350 +/- 40 mumol/day; mean +/- SE) on the third postoperative day, as compared to the TPN group (240 +/- 20 mumol/day). In spite of this the synthesis of alpha-1 antitrypsin was apparently greater in the hypocaloric amino acid than in the TPN group. The accumulated plasma appearance rate of alpha-1 antitrypsin was significantly higher (p = 0.0465) in HAA group, at 70 h it was 490 +/- 40 compared to 400 +/- 20 times the pre-operative synthesis in the TPN group.     

Effects of parenteral infusion with medium-chain triglycerides and safflower oil emulsions on hepatic lipids, plasma amino acids and inflammatory mediators in septic rats

This study was designed to investigate the effects of preinfusion with total parenteral nutrition (TPN) using medium-chain triglycerides (MCT) versus safflower oil (SO) emulsion as fat sources on hepatic lipids, plasma amino acid profiles, and inflammatory-related mediators in septic rats. Normal rats, with internal jugular catheters, were divided into two groups and received TPN. TPN provided 300kcal/kg/day with 40% of the non-protein energy provided as fat. All TPN solutions were isonitrogenous and identical in nutrient composition except for the fat emulsion, which was made of SO or a mixture of MCT and soybean oil (9:1) (MO). After receiving TPN for 6 days, each group of rats was further divided into control and sepsis subgroups. Sepsis was induced by cecal ligation and puncture, whereas control rats received sham operation. All rats were classified into four groups as follows: MCT control group (MOC, n= 8), MCT sepsis group (MOS, n= 8), safflower oil control group (SOC, n= 8), and safflower oil sepsis group (SOS, n= 11). The results of the study demonstrated that the MOS group had lower hepatic lipids than did the SOS group. Plasma leucine and isoleucine levels were significantly lower in the SOS than in the SOC group, but no differences in these two amino acids were observed between the MOC and MOS groups. Plasma arginine levels were significantly lower in septic groups than in those without sepsis despite whether MCT or safflower oil was infused. Plasma glutamine and alanine levels, however, did not differ between septic and non-septic groups either in the SO or MO groups. No differences in interleukin-1b, interleukin-6, tumor necrosis factor-alpha, and leukotriene B(4)concentrations in peritoneal lavage fluid were observed between the two septic groups. These results suggest that catabolic reaction is septic rats preinfused MCT is not as obvious as those preinfused safflower oil. Compared with safflower oil, TPN with MCT administration has better effects on reducing sepsis-induced liver fat deposition. Preinfusion with MCT before sepsis, however, had no effect on inflammatory-related cytokines or leukotriene in peritoneal lavage fluid. In addition, plasma arginine appears to be a more sensitive indicator than glutamine for septic insult.     

Control of diarrhea by fiber-enriched diet in ICU patients on enteral nutrition: a prospective randomized controlled trial

BACKGROUND AND AIMS: Enteral fiber-free diets alter intestinal transit and produce diarrhea or constipation. This prospective double blind, controlled study evaluates the use of guar gum, a soluble fiber and a candidate prebiotic in enteral feeds, to prevent diarrhea and potential health benefits in intensive care unit patients. METHODS: Twenty patients on enteral nutrition with persistent diarrhea were randomized to receive a new enteral feed either enriched with 2% soluble guar gum (study group, n = 10) or fiber-free (control group, n = 10) for 4 successive days. RESULTS: The number of liquid stools in response to a soluble fiber-enriched diet was 2.0+/-0.9 (first day) vs. 1.0+/-0.7 (fourth day) (P < 0.01), and in the control group 1.2+/-0.7 (first day) vs. 2.1+/-0.8 (fourth day) (P < 0.05). In the fiber-enriched feed group, plasma glucose and cholesterol levels at termination of the study, respectively, reached 126+/-81 and 164+/-71 mg dl(-1), as compared to 333+/-108 and 378+/-26 mg dl(-1) on Day first (P < 0.01). In the control group, these values on the fourth day were, respectively, 267+/-94 and 263+/-79 vs. 247+/-115 and 315+/-78 on Day first (P > 0.05). CONCLUSIONS: Guar gum-enriched enteral nutrition was related to a decrease of diarrheal episodes in ICU patients with preexisting diarrhea; and to a trend for lower plasma glucose and cholesterol levels.     

肠内免疫微生态营养对实验性坏死性胰腺炎猪的肝损害的影响

目的观察肠内免疫微生态营养(EIN)对实验性坏死性胰腺炎猪的肝损害的影响.方法20头普通江淮猪胰管注射5％牛磺胆酸钠1 ml/kg制备急性坏死性胰腺炎(ANP)模型,造模后24 h有2头死亡,18头猪按随机数字分组法分为全肠外营养组(TPN)、肠内要素营养组(EEN)和肠内免疫微生态营养组( EIN),分别进行相应的营养8d.于造模前,造模后24h,营养支持第1、2、4、8天检测外周血内毒素、谷草转氨酶(AST)、谷丙转氨酶(ALT)、肿瘤坏死因子-α(TNF-α)、白介素-6(IL-6).营养支持8d后剖腹测定腹水量、肝脏丙二醛(MDA)含量及超氧化物歧化酶(SOD)活力、肝组织TNF-α mRNA和IL-6 mRNA的表达以及肝脏病理学改变,进行病理评分.结果造模后24 h EIN组外周血内毒素、AST、ALT、TNF-α、IL-6均较造模前明显增高(P均＜0.01),但与其他两组的差异无统计学意义.营养支持8d后,EIN组上述5项指标均明显低于TPN组和EEN组(P均＜0.05).营养8d后,EIN组的腹水量、肝脏MDA含量、TNF-α mRNA表达、IL-6 mRNA表达及肝脏病理学评分均明显低于TPN组和EEN组,而肝脏SOD活力则明显高于TPN组和EEN组(P均＜0.05).结论早期给予EIN能从多方面保护ANP引起的肝损害.     

Effects of prolonged, purine-free total parenteral and enteral nutrition on urate homeostasis in man

The influence on human urate homeostasis of prolonged, totally purine-free nutritional support, using total parenteral (TPN) or elemental enteral (EN) nutrition, is not well known. In a prospective study, we measured weekly serum uric acid, renal urate excretion and clearance, together with parameters of hydration, in 58 normally hydrated patients receiving prolonged (15 to 170 days) purine-free TPN (30 patients) or EN (28 patients) for various gastrointestinal disorders. A marked, early and sustained decrease (p less than 0.001) in serum uric acid was observed in TPN (155 +/- 9 mumol/l at day 7 versus 318 +/- 13 mumol/l before nutrition, mean +/- SEM) as well as in EN patients (192 +/- 11 mumol/l at day 7 versus 320 +/- 16 mumol/l before nutrition), together with a significant (p less than 0.01) rise in renal urate clearance. The urate clearance/glomerular filtration rate ratio increased significantly, while there was no significant change in natremia or plasma osmolarity. Serum urate and urate clearance returned to normal within 8 days of refeeding with a normally purine-containing diet. Replacement of TPN by EN or vice versa, or substitution of glucose by fructose resulted in no change in hypouricemia. A 4-day oral supply of purines (125 mg/day) in EN patients was associated with a 53% rise (p less than 0.01) in serum urate. We conclude that prolonged, purine-free TPN and elemental EN are a new cause of marked hypouricemia which is mainly due to increased urate clearance, the mechanism of the latter is still poorly known, but is not related to extracellular volume expansion.     

Parenteral nutrition in bone marrow transplantation

Twenty-nine patients undergoing bone marrow transplantation (BMT) were randomised prospectively to evaluate the effect of parenteral nutrition (TPN) on morbidity and mortality. Fourteen patients received a standard regimen of TPN for 10 +/- 4 days (mean +/- SD). All patients had free access to oral diet, which was significantly reduced compared to pre-transplant intake. In the TPN group, serum bilirubin by day 14 and serum bilirubin and gamma glutamyl transferase by day 21 were significantly higher than in the controls (p < 0.05). These differences probably reflect the higher incidence of serious pyrexia (T > 38.5' C) and blood culture positive rates in the TPN group. Weight loss in the control group was significantly greater than that of the TPN group (p < 0.05). TPN did not affect time to grafting or incidence of graft-versus-host disease. The use of TPN in the nutritional support of patients in small BMT units requires careful consideration.