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Background: Weight loss and muscle wasting are commonly found in patients with end-stage liver disease. Since there is an association between malnutrition and poor clinical outcome, such patients (or those at risk of becoming malnourished) are often given parenteral nutrition, enteral nutrition, or oral nutritional supplements. These interventions have costs and adverse effects, so it is important to prove that their use results in improved morbidity or mortality, or both., Objectives: To assess the beneficial and harmful effects of parenteral nutrition, enteral nutrition, and oral nutritional supplements on the mortality and morbidity of patients with underlying liver disease., Search Methods: The following computerised databases were searched: the Cochrane Hepato-Biliary Group Controlled Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), MEDLINE, EMBASE, and Science Citation Index Expanded (January 2012). In addition, reference lists of identified trials and review articles and Clinicaltrials.gov were searched. Trials identified in a previous systematic handsearch of Index Medicus were also considered. Handsearches of a number of medical journals, including abstracts from annual meetings, were done. Experts in the field and manufacturers of nutrient formulations were contacted for potential references., Selection Criteria: Randomised clinical trials (parallel or cross-over design) comparing groups of patients with any underlying liver disease who received, or did not receive, enteral or parenteral nutrition or oral nutritional supplements were identified without restriction on date, language, or publication status. Six categories of trials were separately considered: medical or surgical patients receiving parenteral nutrition, enteral nutrition, or supplements., Data Collection and Analysis: The following data were sought in each report: date of publication; geographical location; inclusion and exclusion criteria; the type of nutritional support and constitution of the nutrient formulation; duration of treatment; any nutrition provided to the controls; other interventions provided to the patients; number, sex, age of the study participants; hospital or outpatient status; underlying liver disease; risks of bias (sequence generation, allocation concealment, blinding, incomplete outcome reporting, intention-to-treat analysis, selective outcome reporting, others (vested interests, baseline imbalance, early stopping)); mortality; hepatic morbidity (development or resolution of ascites or hepatic encephalopathy, occurrence of gastrointestinal bleeding); quality of life scores; adverse events; infections; lengths of stay in the hospital or intensive care unit; costs; serum bilirubin; postoperative complications (surgical trials only); and nutritional outcomes (nitrogen balance, anthropometric measurements, body weight). The primary outcomes of this review were mortality, hepatic morbidity, quality of life, and adverse events. Data were extracted in duplicate; differences were resolved by consensus.Data for each outcome were combined in a meta-analysis (RevMan 5.1). Estimates were reported using risk ratios or mean differences, along with the 95% confidence intervals (CI). Both fixed-effect and random-effects models were employed; fixed-effect models were reported unless one model, but not the other, found a significant difference (in which case both were reported). Heterogeneity was assessed by the Chi(2) test and I(2) statistic. Subgroup analyses were planned to assess specific liver diseases (alcoholic hepatitis, cirrhosis, hepatocellular carcinoma), acute or chronic liver diseases, and trials employing standard or branched-chain amino acid formulations (for the hepatic encephalopathy outcomes). Sensitivity analyses were planned to compare trials at low and high risk of bias and trials reported as full papers. The following exploratory analyses were undertaken: 1) medical and surgical trials were combined for each nutritional intervention; 2) intention-to-treat analyses in which missing dichotomous data were imputed as best- and worst-case scenarios; 3) all trials were combined to assess mortality; 4) effects were estimated by absolute risk reductions., Main Results: Thirty-seven trials were identified; only one was at low risk of bias. Most of the analyses failed to find any significant differences. The significant findings that were found were the following: 1) icteric medical patients receiving parenteral nutrition had a reduced serum bilirubin (mean difference (MD) -2.86 mg%, 95% CI -3.82 mg% to -1.89 mg%, 3 trials) and better nitrogen balance (MD 3.60 g/day, 95% CI 0.86 g/day to 6.34 g/day, 1 trial); 2) surgical patients receiving parenteral nutrition had a reduced incidence of postoperative ascites only in the fixed-effect model (RR 0.65, 95% CI 0.48 to 0.87, 2 trials, I(2) = 70%) and one trial demonstrated a reduction in postoperative complications, especially infections (pneumonia in particular); 3) enteral nutrition may have improved nitrogen balance in medical patients (although a combination of the three trials was not possible); 4) one surgical trial of enteral nutrition found a reduction in postoperative complications; and 5) oral nutritional supplements had several effects in medical patients (reduced occurrence of ascites (RR 0.57, 95% CI 0.37 to 0.88, 3 trials), possibly (significant differences only seen in the fixed-effect model) reduced rates of infection (RR 0.49, 95% CI 0.24 to 0.99, 3 trials, I(2) = 14%), and improved resolution of hepatic encephalopathy (RR 3.75, 95% CI 1.15 to 12.18, 2 trials, I(2) = 79%). While there was no overall effect of the supplements on mortality in medical patients, the one low risk of bias trial found an increased risk of death in the recipients of the supplements. Three trials of supplements in surgical patients failed to show any significant differences. No new information was derived from the various subgroup or sensitivity analyses. The exploratory analyses were also unrevealing except for a logical conundrum. There was no difference in mortality when all of the trials were combined, but the trials of parenteral nutrition found that those recipients had better survival (RR 0.53, 95% CI 0.29 to 0.98, 10 trials). Either the former observation represents a type II error or the latter one a type I error., Authors' Conclusions: The data do not compellingly justify the routine use of parenteral nutrition, enteral nutrition, or oral nutritional supplements in patients with liver disease. The fact that all but one of these trials were at high risks of bias even casts doubt on the few benefits that were demonstrated. Data from well-designed and executed randomised trials that include an untreated control group are needed before any such recommendation can be made. Future trials have to be powered adequately to see small, but clinically important, differences.

Essential amino acid-based parenteral nutrition (PN) was found to be superior to hypertonic dextrose for patients with acute renal failure in a classical randomized trial that was published in 1973. However, subsequent trials were not able to duplicate this finding when this formulation was compared to hypertonic dextrose or to standard amino acid-based PN. As a result, this intervention has not been recommended in various guidelines for the nutrition support of patients with renal failure. However, all of these trials were relatively small, and none of them compared the intervention to a true control group-namely, patients who were not receiving any artificial nutrition. Because no trials have compared any form of artificial nutrition to no nutrition support in patients with acute renal failure, there really is no basis on which to make any level 1 evidence-based recommendation. Furthermore, a close look at all of the trials suggests that the essential amino acid-based formulation may be superior to the other types of intravenous nutrient supplementation to which it was compared. To determine whether this should be offered to patients with acute renal failure, we need data from one or more large, well-designed and executed, low risk of bias randomized trial(s) comparing essential amino acid-based PN to no nutrition therapy.

Purpose of Review: To assess the recent literature regarding parenteral nutrition to identify publications that have purported to support various beliefs about the utility of parenteral nutrition, and then to critically evaluate the data presented in those (as well as prior) publications., Recent Findings: Artificial nutrition improves nutritional markers but not clinical outcomes, suggesting that malnutrition is not causatively associated with a poor outcome. There are no convincing data that parenteral nutrition is beneficial in severely malnourished surgical patients. Glutamine supplementation of parenteral nutrition solutions may reduce the infectious complication rate, but it is unknown if glutamine-supplemented parenteral nutrition is better than no parenteral nutrition. Most, but not all, systematic reviews have demonstrated that enteral nutrition produces fewer problems than parenteral nutrition; no data suggest that either modality is better than doing no artificial nutrition. Randomized trials have not uniformly been able to demonstrate that parenteral nutrition is efficacious in acute pancreatitis. There is some, but not convincing, data that a regimen of glutamine, growth hormone, and a specialized diet will reduce the need for parenteral nutrition in patients with short bowel syndrome., Summary: It is important for clinicians to be able to critically evaluate the medical literature.

Intravenous (parenteral) nutrition has been advocated widely as adjunctive care in patients with a variety of underlying diseases. However, the enthusiasm for this therapeutic intervention was based largely on expert opinion. Because the best way to assess the efficacy of any treatment is to test it in a randomized controlled trial, this review will focus on data that was derived from such studies. Using established search strategies, randomized controlled trials were sought that compared one of two forms of intravenous nutrition: parenteral nutrition (nitrogen and >or=10 kcal/kg/day of non-protein calories for >or=5 days) or protein-sparing therapy (nitrogen and fewer non-protein calories) with no type of artificial nutrition beyond regular food and/or standard (5%) dextrose. The randomized controlled trials were stratified by the underlying disease state. The clinical outcomes of interest were mortality, morbidity (total/infectious complications), and/or duration of hospitalization. More than 100 randomized controlled trials failed for the most part to demonstrate that intravenous nutrition had any effect on clinical outcome. There were a few exceptions. In patients undergoing attempted curative surgery for upper gastrointestinal cancer, the use of preoperative parenteral nutrition seemed to reduce the incidence of major postoperative complications. However, this benefit was only found in low-quality randomized controlled trials. Findings conflict regarding the use of parenteral nutrition in patients with acute pancreatitis or undergoing bone marrow transplantation. Parenteral nutrition was harmful when provided to patients undergoing radiation or chemotherapy for cancer. Although no randomized controlled trials exist, it is assumed that parenteral nutrition is useful in patients with an inadequate gastrointestinal tract ("short gut"). Thus, for the most part, randomized controlled trials comparing intravenous nutrition to no artificial nutrition have not shown that this medical intervention is of benefit.

Immunonutrients are molecular compounds that, while being dietary components, also influence immunologic response mechanisms. Substances such as glutamine, w-3 fatty acids, arginine, and/or ribonucleic acid have been added to standard nutritional support solutions, and the use of these formulations is known as "immunonutrition." A number of randomized, controlled trials have demonstrated that recipients of immunonutrition have better outcomes than control subjects receiving standard nutritional support. However, it is possible that standard parenteral or enteral nutrition is actually harmful. We currently lack data from randomized trials showing the efficacy of immunonutrition compared with no nutritional support. Even if such information were forthcoming, these immunonutrients may simply be acting as pharmacologic agents. Finally, because each of these nutritive agents may either up- or downregulate the immune response, the effects may be disease-state specific.

This article discusses a study that examines the relationship between inflammatory bowel disease (IBD) and protein-calorie malnutrition (PCM). The study used a large national database to identify patients with IBD who also had PCM and assessed their use of parenteral nutrition (PN) or enteral nutrition (EN). The study found that PCM is more common in hospitalized patients with IBD and has clinical and financial consequences. The use of nutrition support, such as PN or EN, was associated with a decreased risk of readmission, but higher mortality rates. However, the study has limitations, and more research is needed to determine the effectiveness of nutrition support in patients with IBD and PCM. [Extracted from the article]

The article offers information on the catheter-related bloodstream infections provide complication in patients receiving home parenteral nutrition. Topics discussed include information on the randomized clinical trials for the use of heparin, when taurolidine used in the catheter lock; discussions on the clinical signs and symptoms of possible systemic infection; and the importance to limit the number of stratifications.

The article offers the author's insights on topics related to enteral nutrition (EN). Topics mentioned include the comparison of EN and parenteral nutrition (PN), the effects of EN to patients with acute pancreatitis, and the randomized controlled trials on the effects of PN to patients with acute pancreatitis. Also mentioned are the treatment for pancreatitis and the nutrition support to pancreatitis patients.