摘要:

Wasting of muscle and a negative nitrogen balance are obvious effects of malnutrition, and have led to the use of anthropometric measurements and nitrogen balance for its assessment. A positive nitrogen balance and an increase in limb muscle circumference are believed to be solid indices of the beneficial effects of nutritional support. In experiments with growing rats and in young children, nitrogen retention and growth are recognized to be the desirable effects of optimal nutritional intake. This concept has been applied to malnourished adult humans (nongrowing) who have been considered potentially able to “regrow” the lost tissue. Although it is true that patients receiving long‐term (greater than 6 months) home total parenteral nutrition (TPN), gain body weight and nitrogen over many months and years of observation, these processes are not seen during shorter (less than 40 days) periods of nutritional intervention given in hospital. Despite adequate intakes of nitrogen and calories, little or no significant increase in total body nitrogen is seen in a variety of patients receiving TPN in hospital over several weeks, but nutritional support does appear to improve outcome in the form of reduced complications after a period of support so short that body composition is barely altered. For example, Young and Hill showed that although amino acids and amino acids plus calories both resulted in equivalent sparing of body nitrogen, the latter was associated with quicker wound healing and fewer complications. Thus, the outcome and body composition data suggest that reversal of the adverse effects of malnutrition is not based on improvement of the traditional parameters of nutrition, such as gain in body nitrogen, or a demonstrable increase in muscle mass, or in plasma proteins. On the basis of the foregoing evidence, there are grounds for suspecting that functional abnormalities in adult humans may not be the result of simple loss of lean tissue and therefore may recover before such lean tissue is regained. This hypothesis is supported by the observation of Klidjian et al who showed that muscle force is a good measure of outcome. One of the major organ systems of the human body is the musculoskeletal system, and therefore it would seem important to determine the effect of malnutrition on that system. Previous studies of muscle function have been largely related to the examination of fatigue, myopathy, and endocrine‐metabolic abnormalities. Subsequently we undertook initial studies of muscle function in very malnourished patients as outlined below.

ISSN:0148-6071    

DOI:10.1177/0148607188012006539

出版商:SAGE Publications    

年代:1988

数据来源: WILEY

摘要:

The effects of an anabolic steroid (nandrolone decanoate, 5 mg/kg) on postoperative splanchnic fuel metabolism were studied in order to gain further understanding of the regulation of the altered gut/liver amino acid metabolism that occurs following catabolic illness. In addition to studying glutamine and alanine, which together transport 60% of whole blood amino acid nitrogen, we determined the fluxes of glutamate and glucose across the gastrointestinal tract and liver in 12 postoperative dogs. Substrate exchange (flux) was calculated by multiplying bloodflow by the arterial‐venous concentration difference for each substrate. Arterial glutamine, glutamate, and alanine were significantly increased in dogs receiving the anabolic steroid (AS) compared to control animals (p less than 0.05). Intestinal bloodflow was unchanged, but gut glutamine uptake doubled in dogs receiving steroids (1.4 +/‐ 0.3 mumol/kg/min in controls vs 2.8 +/‐ 0.7 in AS, p less than 0.05). Simultaneously, gut alanine release was augmented by 100% in dogs receiving steroids (p less than 0.05). Control dogs demonstrated net glutamate release by the gut, while dogs treated with the anabolic steroid demonstrated glutamate balance (p less than 0.05). Liver bloodflow remained unchanged in AS dogs, but hepatic alanine uptake nearly tripled (p less than 0.01) and hepatic glucose production increased by 60% (p less than 0.05). Anabolic steroids appear to support postoperative splanchnic fuel metabolism by increasing blood amino acid levels, enhancing gut/liver amino acid uptake and processing, and augmenting hepatic gluconeogenesis.

ISSN:0148-6071    

DOI:10.1177/0148607188012006550

出版商:SAGE Publications    

年代:1988

数据来源: WILEY

摘要:

During episodes of trauma carnitine‐free total parenteral nutrition (TPN) may result in a reduction of the total body carnitine pool, leading to a diminished rate of fat oxidation. Sixteen patients undergoing esophagectomy were divided randomly in two equal isonitrogenous groups (0.2 g/kg.day). Both received TPN (35 kcal/kg.day; equally provided as long‐chain triglycerides and glucose) over 11 days without (group A) and with (group B) L‐carnitine supplementation (12 mg/kg.day = 75 mumol/kg.day). Compared with healthy controls, the total body carnitine pool prior to the operation was significantly reduced in both groups, suggesting a state of semistarvation and muscle wasting. In group A the plasma levels of total carnitine and its subfractions (free carnitine, short‐ and long‐chain acylcarnitine) remained stable during the study whereas in group B the total plasma carnitine concentration rose mainly due to an increase in free carnitine. In group A the cumulative urinary carnitine losses were 11.5 +/‐ 2.6 mmol (= 15.5 +/‐ 3.1% of the estimated total body carnitine pool). In group B 3.1 +/‐ 1.9 mmol (= 11.1 +/‐ 7.6%) of the infused carnitine was retained in the immediate postoperative phase until day 6, but this amount was completely lost at completion of the study period. No significant differences in the respiratory quotient or in the plasma levels of triglycerides, free fatty acids, and ketone bodies were observed, between or within the groups, before the operation and after 11 days of treatment. It is concluded that the usefulness of carnitine supplementation during postoperative TPN was not apparent in the present patient material.

ISSN:0148-6071    

DOI:10.1177/0148607188012006555

出版商:SAGE Publications    

年代:1988

数据来源: WILEY

摘要:

In order to investigate the regulatory role of the immune system on gastrointestinal macromolecular permeability in neonates, and ontogeny of the neonatal immune system, we have developed a total parenteral nutrition (TPN) program capable of maintaining immunologically “virgin” germfree (GF) neonatal piglets. GF colostrum‐deprived piglets obtained by aseptic hysterectomy 3–5 days prior to term were denied any oral feeding and maintained on central venous hyperalimentation in the GF isolators. GF piglets were anesthetized and 20‐gauge silicone tubing was inserted into the external jugular vein and advanced to the level of right auricle of the heart. The distal end of the cannula was subcutaneously tunneled out between the shoulders and attached to a light jacket, tether, and swivel assembly that allowed the piglet to move freely inside the cage in a germfree unit. The TPN formula provided 60 Cal/kg/day for the first day and gradually increased up to 165 Cal/kg/day for day‐7 and older piglets. The GF piglets were maintained on the TPN formula for 21 days and weight gain of the GF‐TPN piglets averaged 23 g/day. The hematologic and serum biochemical parameters of GF‐TPN piglets were within the normal range of gnotobiotic animals of their age group. The serum levels of total protein and albumin in the GF‐TPN piglets were significantly less than those of colostrum‐fed piglets, who absorbed a large quantity of the colostral macromolecules through their gastrointestinal tract into the blood stream.(ABSTRACT TRUNCATED AT 250 WORDS)

ISSN:0148-6071    

DOI:10.1177/0148607188012006563

出版商:SAGE Publications    

年代:1988

数据来源: WILEY

摘要:

This study examines the effect of parenteral nutrition on hepatic triglyceride secretion in postoperative patients. Five patients received fluids and electrolytes only (D/S), 10 received a 2000‐kcal total parenteral nutrition (TPN) formula with 25% of the nonprotein energy from lipid (LIPID‐TPN), and 11 received a similar regimen with all of this energy from dextrose (CHO‐TPN). After 7 days an intravenous bolus of 3H‐glycerol was given and hepatic triglyceride secretion measured from the decay curve of plasma radiolabeled triglyceride content. Plasma triglyceride concentrations were similar in each group. Hepatic triglyceride secretion was 16.3 mg/kg/hr after D/S, 10.7 mg/kg/hr after LIPID‐TPN, and 12.2 mg/kg/hr after CHO‐TPN (NS). There was no correlation between the rate of hepatic secretion and dextrose intake. Both TPN regimens resulted in significant reductions in plasma concentrations of apoproteins A1 and B but this did not appear to be related to triglyceride secretion rates. Despite the similar rates of hepatic secretion the quantity of labeled glycerol secreted in triglyceride was significantly greater after CHO‐TPN (17629 dpm/24 hr) than either D/S (10560 dpm/24 hr) or LIPID‐TPN (7264 dpm/24 hr, p less than 0.05), indicating that recycling of exogenous lipid may have occurred after LIPID‐TPN. This study indicates that hepatic triglyceride secretion is not suppressed by TPN, irrespective of the energy source, but suggests that the rate of secretion may have an upper limit.

ISSN:0148-6071    

DOI:10.1177/0148607188012006569

出版商:SAGE Publications    

年代:1988

数据来源: WILEY

摘要:

The splanchnic balance of glucose was studied in the basal state and at three levels of “clamped” hyperinsulinemia (260 +/‐ 23, 510 +/‐ 59, 3875 +/‐ 367 mU/liter) in 24 patients (43–70 years of age), who had undergone coronary surgery about 1 hr previously. The splanchnic balance of glucose in the basal state was negative in all patients (‐1.6 +/‐ 0.3 mg/kg/min) and was changed into a zero‐balance within 30 min when 0.15 or 0.3 U/kg/hr of insulin was infused. At an insulin infusion rate of 1.0 U/kg/hr the net splanchnic glucose balance was turned into a significant positive balance of an average 0.9 +/‐ 0.3 mg/kg/min.

ISSN:0148-6071    

DOI:10.1177/0148607188012006574

出版商:SAGE Publications    

年代:1988

数据来源: WILEY

摘要:

Twenty‐one dogs underwent instrumentation of the left ventricle with ultrasonic dimension to study the effects of acute protein‐calorie malnutrition on the adrenergic responsiveness of the heart. This study allowed a chronic and dynamic measurement of the major cardiac axes and the ventricular wall thickness, which in turn can be used to derive sophisticated measurements of global and intrinsic left ventricular function. Of the 21 dogs, 11 received a protein‐ and calorie‐deficient diet designed to achieve a mean weight loss from a baseline of 20–25% over a 4‐week period. The other 10 dogs received a normal diet. Dogs were also randomized to receive either acute propranolol beta‐receptor blockade (n = 9) or acute isoproterenol beta‐receptor stimulation (n = 12) during their baseline studies. Of the nine dogs given propranolol, five were subsequently malnourished and four served as controls. Of the 12 given isoproterenol, six were rendered malnourished and six were controls. All dogs were studied at both baseline and 4 weeks and received drugs in an identical fashion during both studies. The significant changes with malnutrition consisted of decreases in heart rate, cardiac mass, and left ventricular wall thickness. The degree of change in stroke volume, ejection fraction, cardiac output, dp/dt, and Emax (index of left ventricular contractility), with the administration of propranolol or isoproterenol was unaltered by malnutrition. These data support the contention that moderate protein‐calorie malnutrition is well tolerated in instrumented, unstessed dogs and that the left ventricle's capacity to respond to beta‐stimulation and to tolerate beta‐blockade is largely unimpaired.

ISSN:0148-6071    

DOI:10.1177/0148607188012006579

出版商:SAGE Publications    

年代:1988

数据来源: WILEY

摘要:

Patients undergoing major gastrointestinal surgery who had a prognostic nutritional index (PNI) score of greater than 30% were randomized to receive a preoperative course of 10 days of intravenous nutrition or to undergo surgery at the next convenient operation list. Two groups of 17 patients were well matched for age, sex, and nutritional status. Although they underwent diverse operations, the extent of these was similar: 12 +/‐ 3 days of parenteral nutrition resulted in weight gain, 3.2 +/‐ 2.3 kg p less than 0.01; increased triceps skinfold, 0.6 +/‐ 1.2 mm p less than 0.05; improved immunological state, p less than 0.02; and improved PNI, 5.5 +/‐ 10.1% p less than 0.05. The changes in serum albumin and transferrin were not significant. There were only three major complications with one death in the treatment group but this was not significantly different from the control group which had six major complications and three deaths. This study suggests that patients with demonstrable nutritional depletion who require major gastrointestinal surgery will benefit from a preoperative course of parenteral nutrition, but to conclusively prove this a large and probably multicentre study will be required.

ISSN:0148-6071    

DOI:10.1177/0148607188012006587

出版商:SAGE Publications    

年代:1988

数据来源: WILEY

摘要:

The purpose of this study was to evaluate the use of serum fibronectin and serum somatomedin‐C as nutritional markers during enteral nutrition support (ENS) of critically ill, traumatized patients using an enteral product containing high concentrations of branched‐chain amino acids. Twelve critically injured patients received a standard enteral formula with 30 g of a 44% branched‐chain amino acid supplement added to each liter of formula. Fibronectin concentration, somatomedin‐C concentration, and nitrogen balance were measured on study days 1, 4, 7, 14, 21, 28 or until adequate oral intake began. Both fibronectin and somatomedin‐C concentrations increased significantly from baseline by day 7 of ENS. Nitrogen balance increased significantly from baseline by day 4. On days 14 and 21, only somatomedin‐C and nitrogen balance increased significantly from baseline. Nitrogen balance was significantly correlated with somatomedin‐C concentration (r = 0.53, p less than 0.01), cumulative caloric intake (r = 0.68, p less than 0.01), and cumulative nitrogen intake (r = 0.72, p less than 0.01). The results of this study suggest that serum somatomedin‐C is useful and serum fibronectin has potential in monitoring nutrition support response in critically ill, traumatized patients.

ISSN:0148-6071    

DOI:10.1177/0148607188012006592

出版商:SAGE Publications    

年代:1988

数据来源: WILEY

摘要:

Nitrogen metabolism and plasma insulin level were studied postoperatively in 14 patients (six males and eight females) with a disease of the upper gastrointestinal tract and therefore operated on electively. The patients received one of the two isocaloric parenteral nutrition regimens postoperatively: one, on the average, with 1.2 g of amino acids/kg/day and the other with 3.1 g of amino acids/kg/day. During postoperative intravenous alimentation rich in amino acids the cumulative nitrogen balance over 3 days was +13.1 (interval from ‐1.3 to +21.4) gN but ‐10.1 (interval from ‐12.1 to ‐2.4) gN during parenteral nutrition with a smaller amount of amino acids. The difference was significant (p less than 0.001). During parenteral nutrition rich in amino acids the changes of the serum albumin level, ie, ‐0.4 (SEM 1.1) g/liter, and of the serum transferrin level, ie; ‐0.16 (SEM 0.22) g/liter, were statistically insignificant (p greater than 0.05). During intravenous alimentation poor in amino acids serum albumin decreased by 3.8 (SEM 1.2) g/liter (p less than 0.01) and serum transferrin by 0.44 (SEM 0.05) g/liter (p less than 0.001). The differences of the changes between the groups were significant (p less than 0.01 and p less than 0.01, respectively). These various effects of the two parenteral nutrition regimens were not dependent on the different fluid balances during intravenous alimentation or on the different plasma insulin levels. It is concluded that a rich supply of amino acids‐‐more than 1.2 g/kg/day‐‐in postoperative parenteral nutrition better maintains the visceral protein levels in the serum, which possibly depends on the greater protein production in the liver.

ISSN:0148-6071    

DOI:10.1177/0148607188012006597

出版商:SAGE Publications    

年代:1988

数据来源: WILEY