Nutritional support and neurotrauma: a critical review of early nutrition in forty-five acute head injury patients

Mortality and overall and specific infection complication rates in patients who receive parenteral nutrition: systematic review and meta-analysis with trial sequential analysis

BACKGROUND

Parenteral nutrition (PN) is an available option for nutritional therapy and is often required in the hospital setting to overcome malnutrition.

OBJECTIVES

The aim of this study was to assess whether PN is associated with an increased risk of mortality or infectious complications in all groups of hospitalized patients compared with those receiving other nutritional support strategies.

METHODS

For this systematic review and meta-analysis MEDLINE, Embase, Cochrane Central, Scopus, clinicaltrials.gov, and Web of Science were searched for randomized controlled trials (RCTs) and observational studies with parallel groups that explored the effect of PN on mortality and infectious complications, published until March 2021. Two independent reviewers extracted the data and assessed the risk of bias. Fixed-effects meta-analysis was performed to compare the groups from RCTs. Trial sequential analysis (TSA) was used to identify whether the results were sufficient to reach definitive conclusions.

RESULTS

Of the 83 included studies that compared patients receiving PN with those receiving other strategies, 67 RCTs were included in the meta-analysis. PN was not associated with a higher risk of mortality (RR: 1.01; 95% CI: 0.95, 1.07). On the other hand, PN was associated with a higher risk of infectious events (RR: 1.23; 95% CI: 1.12, 1.36). PN was specifically associated with abdominal infection and catheter infection. The TSA showed that there were sufficient data to make numerical conclusions about mortality, any infectious event, and abdominal infectious complications.

CONCLUSIONS

This study suggests that although PN is not associated with greater mortality in hospitalized patients, it is associated with infectious complications. Through TSA, definite conclusions about survival and infection rates could be made.This review was registered at www.crd.york.ac.uk/prospero/ as CRD42018075599.

The neurosurgical wound and factors that can affect cosmetic, functional, and neurological outcomes

Surgically accessing pathological lesions located within the central nervous system (CNS) frequently requires creating an incision in cosmetic regions of the head and neck. The biggest factors of surgical success typically tend to focus on the middle portion of the surgery, but a vast majority of surgical complications tend to happen towards the end of a case, during closure of the surgical site incisions. One of the most difficult complications for a surgeon to deal with is having to take a patient back to the operating room for wound breakdowns and, even worse, wound or CNS infections, which can negate all the positive outcomes from the surgery itself. In this paper, we discuss the underlying anatomy, pharmacological considerations, surgical techniques and nutritional needs necessary to help facilitate appropriate wound healing. A successful surgery begins with preoperative planning regarding the placement of the surgical incision, being cognizant of cosmetics, and the effects of possible adjuvant radiation therapy on healing incisions. We need to assess patient's medications and past medical history to make sure we can optimise conditions for proper wound reepithelialisation, such as minimizing the amount of steroids and certain antibiotics. Contrary to harmful medications, it is imperative to optimise nutritional intake with adequate supplementation and vitamin intake. The goals of this paper are to reinforce the mechanisms by which surgical wounds can fail, leading to postoperative complications, and to provide surgeons with the reminder and techniques that can help foster a more successful surgical outcome.

Nutritional support for critically ill children

BACKGROUND

Nutritional support in the critically ill child has not been well investigated and is a controversial topic within paediatric intensive care. There are no clear guidelines as to the best form or timing of nutrition in critically ill infants and children. This is an update of a review that was originally published in 2009. .

OBJECTIVES

The objective of this review was to assess the impact of enteral and parenteral nutrition given in the first week of illness on clinically important outcomes in critically ill children. There were two primary hypotheses:1. the mortality rate of critically ill children fed enterally or parenterally is different to that of children who are given no nutrition;2. the mortality rate of critically ill children fed enterally is different to that of children fed parenterally.We planned to conduct subgroup analyses, pending available data, to examine whether the treatment effect was altered by:a. age (infants less than one year versus children greater than or equal to one year old);b. type of patient (medical, where purpose of admission to intensive care unit (ICU) is for medical illness (without surgical intervention immediately prior to admission), versus surgical, where purpose of admission to ICU is for postoperative care or care after trauma).We also proposed the following secondary hypotheses (a priori), pending other clinical trials becoming available, to examine nutrition more distinctly:3. the mortality rate is different in children who are given enteral nutrition alone versus enteral and parenteral combined;4. the mortality rate is different in children who are given both enteral feeds and parenteral nutrition versus no nutrition.

SEARCH METHODS

In this updated review we searched: the Cochrane Central Register of Controlled Trials (CENTRAL 2016, Issue 2); Ovid MEDLINE (1966 to February 2016); Ovid EMBASE (1988 to February 2016); OVID Evidence-Based Medicine Reviews; ISI Web of Science - Science Citation Index Expanded (1965 to February 2016); WebSPIRS Biological Abstracts (1969 to February 2016); and WebSPIRS CAB Abstracts (1972 to February 2016). We also searched trial registries, reviewed reference lists of all potentially relevant studies, handsearched relevant conference proceedings, and contacted experts in the area and manufacturers of enteral and parenteral nutrition products. We did not limit the search by language or publication status.

SELECTION CRITERIA

We included studies if they were randomized controlled trials; involved paediatric patients, aged one day to 18 years of age, who were cared for in a paediatric intensive care unit setting (PICU) and had received nutrition within the first seven days of admission; and reported data for at least one of the pre-specified outcomes (30-day or PICU mortality; length of stay in PICU or hospital; number of ventilator days; and morbid complications, such as nosocomial infections). We excluded studies if they only reported nutritional outcomes, quality of life assessments, or economic implications. Furthermore, we did not address other areas of paediatric nutrition, such as immunonutrition and different routes of delivering enteral nutrition, in this review.

DATA COLLECTION AND ANALYSIS

Two authors independently screened the searches, applied the inclusion criteria, and performed 'Risk of bias' assessments. We resolved discrepancies through discussion and consensus. One author extracted data and a second checked data for accuracy and completeness. We graded the evidence based on the following domains: study limitations, consistency of effect, imprecision, indirectness, and publication bias.

MAIN RESULTS

We identified only one trial as relevant. Seventy-seven children in intensive care with burns involving more than 25% of the total body surface area were randomized to either enteral nutrition within 24 hours or after at least 48 hours. No statistically significant differences were observed for mortality, sepsis, ventilator days, length of stay, unexpected adverse events, resting energy expenditure, nitrogen balance, or albumin levels. We assessed the trial as having unclear risk of bias. We consider the quality of the evidence to be very low due to there being only one small trial. In the most recent search update we identified a protocol for a relevant randomized controlled trial examining the impact of withholding early parenteral nutrition completing enteral nutrition in pediatric critically ill patients; no results have been published.

AUTHORS' CONCLUSIONS

There was only one randomized trial relevant to the review question. Research is urgently needed to identify best practices regarding the timing and forms of nutrition for critically ill infants and children.

Nutritional support for patients sustaining traumatic brain injury: a systematic review and meta-analysis of prospective studies

Background

In traumatic brain injury (TBI), the appropriate timing and route of feeding, and the efficacy of immune-enhancing formulae have not been well established. We performed this meta-analysis aiming to compare the effects of different nutritional support modalities on clinical outcomes of TBI patients.

Methods

We systematically searched Pubmed, Embase, and the Cochrane Library until October, 2012. All randomized controlled trials (RCTs) and non-randomized prospective studies (NPSs) that compared the effects of different routes, timings, or formulae of feeding on outcomes in TBI patients were selected. The primary outcomes included mortality and poor outcome. The secondary outcomes included the length of hospital stay, the length of ventilation days, and the rate of infectious or feeding-related complications.

Findings

13 RCTs and 3 NPSs were included. The pooled data demonstrated that, compared with delayed feeding, early feeding was associated with a significant reduction in the rate of mortality (relative risk [RR] = 0.35; 95% CI, 0.24–0.50), poor outcome (RR = 0.70; 95% CI, 0.54–0.91), and infectious complications (RR = 0.77; 95% CI, 0.59–0.99). Compared with enteral nutrition, parenteral nutrition showed a slight trend of reduction in the rate of mortality (RR = 0.61; 95% CI, 0.34–1.09), poor outcome (RR = 0.73; 95% CI, 0.51–1.04), and infectious complications (RR = 0.89; 95% CI, 0.66–1.22), whereas without statistical significances. The immune-enhancing formula was associated with a significant reduction in infection rate compared with the standard formula (RR = 0.54; 95% CI, 0.35–0.82). Small-bowel feeding was found to be with a decreasing rate of pneumonia compared with nasogastric feeding (RR = 0.41; 95% CI, 0.22–0.76).

Conclusion

After TBI, early initiation of nutrition is recommended. It appears that parenteral nutrition is superior to enteral nutrition in improving outcomes. Our results lend support to the use of small-bowel feeding and immune-enhancing formulae in reducing infectious complications.

Contemporary pharmacologic issues in the management of traumatic brain injury

Traumatic brain injury (TBI) is a major cause of death and disability in the United States. While there are no pharmacotherapeutic options currently available for attenuating the neurologic injury cascade after TBI, numerous pharmacologic issues are encountered in these critically ill patients. Adequate fluid resuscitation, reversal of coagulopathy, maintenance of cerebral perfusion, and treatment of intracranial hypertension are common interventions early in the treatment of TBI. Other deleterious complications such as venous thromboembolism, extremes in glucose concentrations, and stress-related mucosal disease should be anticipated and avoided. Early provision of nutrition and prevention of drug or alcohol withdrawal are also cornerstones of routine care in TBI patients. Prevention of infections and seizures may also be helpful. Clinicians caring for TBI patients should be familiar with the pharmacologic issues typical of this vulnerable population in order to develop optimal strategies of care to anticipate and prevent common complications.

The role of parenteral nutrition as a supplement to enteral nutrition in patients with severe brain injury

Enteral nutrition (EN) is the preferred and safe route of feeding in surgical patients incapable of self-nutrition. We describe three patients with severe brain insult and recurrent sepsis, who despite the early introduction of EN, remained hypoalbuminaemic, hypoproteinaemic and developed peripheral oedema. This state persisted, despite increasing the caloric and protein intake via the enteral route. However, after a short course of supplemental parenteral nutrition (PN), albumin and total protein levels improved, with resolution of peripheral oedema. We hypothesize that, in certain critically ill neurosurgical patients on EN, gastrointestinal malabsorption may underlie a persistently low serum albumin, total protein and peripheral oedema. A short course of supplemental PN may help to reverse this and a normal regimen of EN can then be continued.

Nutritional support for critically ill children

BACKGROUND

Nutritional support in the critically ill child has not been well investigated and is a controversial topic within paediatric intensive care. There are no clear guidelines as to the best form or timing of nutrition in critically ill infants and children.

OBJECTIVES

To assess the impact of enteral and total parenteral nutrition on clinically important outcomes for critically ill children.

SEARCH STRATEGY

We searched: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2007, Issue 1); Ovid MEDLINE (1966 to February 2007); Ovid EMBASE (1988 to February 2007); OVID Evidence-Based Medicine Reviews; ISI Web of Science - Science Citation Index Expanded (1965 to February 2007); WebSPIRS Biological Abstracts (1969 to February 2007); and WebSPIRS CAB Abstracts (1972 to February 2007). We also searched trial registries; reviewed reference lists of all potentially relevant studies; handsearched relevant conference proceedings; and contacted experts in the area and manufacturers of enteral and parenteral nutrition products. We did not limit the search by language or publication status.

SELECTION CRITERIA

We included studies if they were randomized controlled trials; involved paediatric patients, aged one day to 18 years of age, cared for in a paediatric intensive care unit setting (PICU) and received nutrition within the first seven days of admission; and reported data for at least one of the pre-specified outcomes (30-day or PICU mortality; length of stay in PICU or hospital; number of ventilator days; and morbid complications, such as nosocomial infections). We excluded studies if they only reported nutritional outcomes, quality of life assessments, or economic implications. Furthermore, other areas of paediatric nutrition, such as immunonutrition and different routes of delivering enteral nutrition, were not addressed in this review.

DATA COLLECTION AND ANALYSIS

Two authors independently screened searches, applied inclusion criteria, and performed quality assessments. We resolved discrepancies through discussion and consensus. One author extracted data and a second checked data for accuracy and completeness.

MAIN RESULTS

Only one trial was identified as relevant. Seventy-seven children in intensive care with burns involving > 25% of the total body surface area were randomized to either enteral nutrition within 24 hours or after at least 48 hours. No statistically significant differences were observed for mortality, sepsis, ventilator days, length of stay, unexpected adverse events, resting energy expenditure, nitrogen balance, or albumin levels. The trial was assessed as of low methodological quality (based on the Jadad scale) with an unclear risk of bias.

AUTHORS' CONCLUSIONS

There was only one randomized trial relevant to the review question. Research is urgently needed to identify best practices regarding the timing and forms of nutrition for critically ill infants and children.

Feeding critically ill patients: what is the optimal amount of energy?

Hypermetabolism and malnourishment are common in the intensive care unit. Malnutrition is associated with increased morbidity and mortality, and most intensive care unit patients receive specialized nutrition therapy to attenuate the effects of malnourishment. However, the optimal amount of energy to deliver is unknown, with some studies suggesting that full calorie feeding improves clinical outcomes but other studies concluding that caloric intake may not be important in determining outcome. In this narrative review, we discuss the studies of critically ill patients that examine the relationship between dose of nutrition and clinically important outcomes. Observational studies suggest that achieving targeted caloric intake might not be necessary since provision of approximately 25% to 66% of goal calories may be sufficient. Randomized controlled trials comparing early aggressive use of enteral nutrition compared with delayed, less aggressive use of enteral nutrition suggest that providing increased calories with early, aggressive enteral nutrition is associated with improved clinical outcomes. However, energy provision with parenteral nutrition, either instead of or supplemental to enteral nutrition, does not offer additional benefits. In summary, the optimal amount of calories to provide critically ill patients is unclear given the limitations of the existing data. However, evidence suggests that improving adequacy of enteral nutrition by moving intake closer to goal calories might be associated with a clinical benefit. There is no role for supplemental parenteral nutrition to increase caloric delivery in the early phase of critical illness. Further high-quality evidence from randomized trials investigating the optimal amount of energy intake in intensive care unit patients is needed.

Nutrition support in clinical practice: review of published data and recommendations for future research directions

In the last 30 years, marked advances in enteral feeding techniques, venous access, and enteral and parenteral nutrient formulations have made it possible to provide nutrition support to almost all patients. Despite the abundant medical literature and widespread use of nutritional therapy, many areas of nutrition support remain controversial. Therefore, the leadership at the National Institutes of Health, The American Society for Parenteral and Enteral Nutrition, and The American Society for Clinical Nutrition convened an advisory committee to perform a critical review of the current medical literature evaluating the clinical use of nutrition support; the goal was to assess our current body of knowledge and to identify the issues that deserve further investigation. The panel was divided into five groups to evaluate the following areas: nutrition assessment, nutrition support in patients with gastrointestinal diseases, nutrition support in wasting diseases, nutrition support in critically ill patients, and perioperative nutrition support. The findings from each group are summarized in this report. This document is not meant to establish practice guidelines for nutrition support. The use of nutritional therapy requires a careful integration of data from pertinent clinical trials, clinical expertise in the illness or injury being treated, clinical expertise in nutritional therapy, and input from the patient and his/her family.

The effect of metoclopramide on gastric emptying in traumatic brain injury

OBJECTIVE

Gastric paresis in traumatic brain injury (TBI) hinders the effectiveness of enteral support in this patient group. In this study we have investigated the effect of metoclopramide on gastric emptying in TBI patients.

METHOD

In this prospective, randomized, controlled, double-blind study, 19 TBI patients with Glasgow Coma Scale scores of 3-11 were included. In all patients, enteral nutrition was commenced with a nasogastric feeding tube within 48 hours of trauma. Patients were randomized into two groups. In the metoclopramide (M) group, 10 mg metoclopramide was delivered intravenously three times daily for 5 days. In the control (C) group, an equal volume of saline was administered. Besides demographics, gastric emptying according to a paracetamol absorption test at days 0 and 5, time to reach target nutritional requirements, gastric residues, intolerance to feeding, nutritional complications, and clinical outcomes were recorded for each patient.

RESULTS

The gastric residue rates were 2.7+/-7.4 mL and 8.1+/-17.7 mL per 100 patient days for groups C and M respectively (p=0.408). Similarly, feeding intolerance and complication rates did not significantly differ between groups C and M, (respectively p=0.543 and 0.930). Gastric emptying parameters also were similar between the study groups.

CONCLUSION

We were unable to document any advantage to using metoclopramide in TBI patients. Simple intragastric enteral feeding with close monitoring of the possible complications seems to be sufficient with acceptable morbidity rates.

Metabolism and nutrition in patients with moderate and severe traumatic brain injury: A systematic review

PRIMARY OBJECTIVE

To examine the evidence on the metabolic state and nutritional treatment of patients with moderate-to-severe traumatic brain injury (TBI).

RESEARCH DESIGN

A systematic review of the literature.

METHODS AND PROCEDURES

From 1547 citations, 232 articles were identified and retrieved for text screening. Thirty-six studies fulfilled the criteria and 30 were accepted for data extraction.

MAIN OUTCOMES AND RESULTS

Variations in measurement methods and definitions of metabolic abnormalities hampered comparison of studies. However, consistent data demonstrated increased metabolic rate (96-160% of the predicted values), of hypercatabolism (-3 to -16 g N per day) and of upper gastrointestinal intolerance in the majority of the patients during the first 2 weeks after injury. Data also indicated a tendency towards less morbidity and mortality in early fed patients.

CONCLUSIONS

The impact of timing, content and ways of administration of nutritional support on neurological outcome after TBI remains to be demonstrated.

Nutritional support for head-injured patients

BACKGROUND

Head injury increases the body's metabolic responses, and therefore nutritional demands. Provision of an adequate supply of nutrients is associated with improved outcome. The best route for administering nutrition (parenterally (TPN) or enterally (EN)), and the best timing of administration (for example, early versus late) of nutrients needs to be established.

OBJECTIVES

To quantify the effect on mortality and morbidity of alternative strategies of providing nutritional support following head injury.

SEARCH STRATEGY

Trials were identified by computerised searches of the Cochrane Injuries Group specialised register, Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, National Research Register, Web of Science and other electronic trials registers. Reference lists of trials and review articles were checked. The searches were last updated in July 2006.

SELECTION CRITERIA

Randomised controlled trials of timing or route of nutritional support following acute traumatic brain injury.

DATA COLLECTION AND ANALYSIS

Two authors independently abstracted data and assessed trial quality. Information was collected on death, disability, and incidence of infection. If trial quality was unclear, or if there were missing outcome data, trialists were contacted in an attempt to get further information.

MAIN RESULTS

A total of 11 trials were included. Seven trials addressed the timing of support (early versus delayed), data on mortality were obtained for all seven trials (284 participants). The relative risk (RR) for death with early nutritional support was 0.67 (95% CI 0.41 to 1.07). Data on disability were available for three trials. The RR for death or disability at the end of follow-up was 0.75 (95% CI 0.50 to 1.11). Seven trials compared parenteral versus enteral nutrition. Because early support often involves parenteral nutrition, three of the trials are also included in the previous analyses. Five trials (207 participants) reported mortality. The RR for mortality at the end of follow-up period was 0.66 (0.41 to 1.07). Two trials provided data on death and disability. The RR was 0.69 (95% Cl 0.40 to 1.19). One trial compared gastric versus jejunal enteral nutrition, there were no deaths and the RR was not estimable.

AUTHORS' CONCLUSIONS

This review suggests that early feeding may be associated with a trend towards better outcomes in terms of survival and disability. Further trials are required. These trials should report not only nutritional outcomes but also the effect on death and disability.

Preliminary Evidence for a Medical Nutrition Therapy Protocol: Enteral Feedings for Critically Ill Patients

The objective of this study was to evaluate the evidence behind specific but common patient care decisions in support of enteral feedings for patients admitted to intensive care units. Six specific questions were developed and refined to address clinical outcomes specific to clinical practice decisions pertinent to enteral feeding of critically ill patients. The data sources consisted of an intensive literature review from five databases, using standardized search terms. Randomized controlled clinical trials, meta-analyses, consensus statements, reviews, US Food and Drug Administration alerts, and case reports were selected for study. Research reports were abstracted in detail and evaluated for research quality using the criteria developed by the American Dietetic Association. Consensus statements regarding the influence of specific enteral feeding methods on key clinical outcomes (ie, infectious complications, cost, length of hospital stay, and mortality) were developed and graded based on the quality of the available evidence. The data support the use of enteral over parenteral nutrition to reduce infectious complications and cost, and the initiation of enteral feedings within 24 to 48 hours of injury or admission to an intensive care unit to reduce infectious complications and length of hospital stay in head injury and trauma patients. Postpyloric tube placement is associated with reduced gastric residual volume and reflux, but adequately powered trials are not available to support prevention of aspiration pneumonia. Acceptance of gastric residual volumes of up to 250 mL may increase volume of formula delivered. Promotility agents are associated with reduced gastric residual volume. Feeding patients in the semirecumbent rather than supine position is associated with reduced aspiration pneumonia and pharyngoesophageal formula reflux. Actual delivery of 14 to 18 kcal/kg/day or 60% to 70% of goal is associated with improved outcomes, whereas greater intake may not be in some populations. Blue food coloring should not be used with enteral feedings due to its limited sensitivity for aspiration and some risk of mortality. Well-designed, adequately powered, randomized controlled clinical trials are needed to evaluate any benefit of tube tip position on aspiration pneumonia or mortality, and of early enteral feedings on mortality.

ESPEN Guidelines on Enteral Nutrition: Intensive care

Enteral nutrition (EN) via tube feeding is, today, the preferred way of feeding the critically ill patient and an important means of counteracting for the catabolic state induced by severe diseases. These guidelines are intended to give evidence-based recommendations for the use of EN in patients who have a complicated course during their ICU stay, focusing particularly on those who develop a severe inflammatory response, i.e. patients who have failure of at least one organ during their ICU stay. These guidelines were developed by an interdisciplinary expert group in accordance with officially accepted standards and are based on all relevant publications since 1985. They were discussed and accepted in a consensus conference. EN should be given to all ICU patients who are not expected to be taking a full oral diet within three days. It should have begun during the first 24h using a standard high-protein formula. During the acute and initial phases of critical illness an exogenous energy supply in excess of 20-25 kcal/kg BW/day should be avoided, whereas, during recovery, the aim should be to provide values of 25-30 total kcal/kg BW/day. Supplementary parenteral nutrition remains a reserve tool and should be given only to those patients who do not reach their target nutrient intake on EN alone. There is no general indication for immune-modulating formulae in patients with severe illness or sepsis and an APACHE II Score >15. Glutamine should be supplemented in patients suffering from burns or trauma.

Parenteral nutrition in adult inpatients with functioning gastrointestinal tracts: assessment of outcomes

Malnutrition is a common comorbidity that places inpatients at risk of complications, infections, long length of stay, higher costs, and increased mortality. Thus, nutrition support has become an important therapeutic adjunctive to the care of these patients. For patients unable to feed themselves, nutrition can be delivered via the parenteral or enteral routes. The formulations used to deliver nutrients and the route of nutrient delivery, absorption, and processing differ substantially between parenteral and enteral nutrition. Over the past two decades, many randomised clinical trials have assessed the effects of parenteral versus enteral nutrition on outcomes (ie, complications, infections, length of stay, costs, mortality) in diverse inpatient populations. From a search of medical publications, studies were selected that assessed important clinical outcomes of parenteral versus enteral feeding or intravenous fluids in patients with trauma/burn injuries, surgery, cancer, pancreatic disease, inflammatory bowel disease, critical illness, liver failure, acute renal failure, and organ transplantation. Our goal was to determine the optimum route of feeding in these patient groups. The available evidence lends support to the use of enteral over parenteral feeding in inpatients with functioning gastrointestinal tracts.

Does enteral nutrition compared to parenteral nutrition result in better outcomes in critically ill adult patients? A systematic review of the literature

OBJECTIVE

Nutritional support is part of the standard of care for the critically ill adult patient. In the average patient in the intensive care unit who has no contraindications to enteral nutrition (EN) or parenteral nutrition (PN), the choice of route for nutritional support may be influenced by several factors. Because EN and PN are associated with risks and benefits, we systematically reviewed and critically appraised the literature to compare EN with PN the critically ill patient.

METHODS

We searched computerized bibliographic databases, personal files, and relevant reference lists to identify potentially eligible studies. Only randomized clinical trials that compared EN with PN in critically ill patients with respect to clinically important outcomes were included in this review. In an independent fashion, relevant data on the methodology and outcomes of primary studies were abstracted in duplicate. The studies were subsequently aggregated statistically.

RESULTS

There were 13 studies that met the inclusion criteria and, hence, were included in our meta-analysis. The use of EN as opposed to PN was associated with a significant decrease in infectious complications (relative risk = 0.64, 95% confidence interval = 0.47 to 0.87, P = 0.004) but not with any difference in mortality rate (relative risk = 1.08, 95% confidence interval = 0.70 to 1.65, P = 0.7). There was no difference in the number of days on a ventilator or length of stay in the hospital between groups receiving EN or PN (Standardized Mean Difference [SMD] = 0.07, 95% confidence interval = -0.2 to 0.33, P = 0.6). PN was associated with a higher incidence of hyperglycemia. Data that compared days on a ventilator and the development of diarrhea in patients who received EN versus PN were inconclusive. In the EN and PN groups, complications with enteral and parenteral access were seen. Four studies documented cost savings with EN as opposed to PN.

CONCLUSION

The use of EN as opposed to PN results in an important decrease in the incidence of infectious complications in the critically ill and may be less costly. EN should be the first choice for nutritional support in the critically ill.

Management of Increased Intracranial Pressure in the Critically Ill Child With an Acute Neurological Injury

Increased intracranial pressure reflects the presence of mass effect in the brain and is associated with a poor outcome in children with acute neurological injury. If sustained, it has a negative effect on cerebral blood flow and cerebral perfusion pressure, can cause direct compression of vital cerebral structures, and can lead to herniation. The management of the patient with increased intracranial pressure involves the maintenance of an adequate cerebral perfusion pressure, prevention of intracranial hypertension, and optimization of oxygen delivery. This article reviews the neurological assessment, pathophysiology, and management of increased intracranial pressure in the critically ill child who has sustained an acute neurological injury.

Guidelines for nutritional support in intensive care unit patients: a critical analysis

PURPOSE OF REVIEW

Guidelines are supposed to be helpful in clinical practice. Guidelines are also supposed to rest upon the evidence that there is. In the field of clinical nutrition the problem is that many clinical trials are not conclusive because they are underpowered and sometimes have an inferior design.

RECENT FINDINGS

The publication of the Canadian guidelines one year ago initiated a lively debate. The Canadian guidelines used meta-analysis as a tool to review the literature. This resulted in both a sound evaluation of studies as well as some controversial recommendations. The Canadian guidelines are here put in a perspective in which the older type of guidelines are compared, and some of the points of recommendation are scrutinized.

SUMMARY

What all guidelines agree upon is the shortage of solid knowledge, the conviction that complications related to nutritional therapy in the intensive care unit are not acceptable, and that enteral nutrition is preferable if it can be given without risk. Beyond that, many controversies remain and the need for high quality prospective studies must be emphasized. In addition, such studies must address the clinically important questions that the guidelines try to answer.

A metaanalysis of treatment outcomes of early enteral versus early parenteral nutrition in hospitalized patients

OBJECTIVE

Nutritional support as enteral or parenteral nutrition (PN) is used in hospitalized patients to reduce catabolism. This study compares outcomes of early enteral nutrition (EN) with early PN in hospitalized patients.

DESIGN

The authors conducted a metaanalysis of randomized, controlled trials (RCT) comparing early EN with PN. Studies on immunonutrition were excluded. Studies were categorized as medical, surgical, or trauma.

PATIENTS

RCTs of early EN/PN were identified by search of 1) MEDLINE (1966-2002), 2) published abstracts from scientific meetings, and 3) bibliographies of relevant articles.

MEASUREMENTS AND MAIN RESULTS

Thirty RCTs (ten medical, 11 surgical, and nine trauma) compared early EN with PN. The effect of nutrition type on hospital mortality and complication rates was reported as risk difference (RD%) and hospital length of stay (LOS) as mean weighted difference (MWD days). Missing data, by outcomes, varied from 20% to 63%. As a result of heterogeneity of treatment effects, the DerSimonian-Laird random-effects estimator was reported. There was no differential treatment effect of nutrition type on hospital mortality for all patients (0.6%, p = .4) and subgroups. PN was associated with increases in infective complications (7.9%, p = .001), catheter-related blood stream infections (3.5%, p = .003), noninfective complications (4.9%, p = .04), and hospital LOS (1.2 days, p = .004). There was no effect of nutrition type on technical complications (4.1%, p = .2). EN was associated with a significant increase in diarrheal episodes (8.7%, p = .001). Publication bias was not demonstrated. Metaanalytic regression analysis did not demonstrate any effect of age, time to initiate treatment, and average albumin on mortality estimates. Cumulative metaanalysis showed no change in the mortality estimates with time.

CONCLUSION

There was no mortality effect with the type of nutritional supplementation. Although early EN significantly reduced complication rates, this needs to be interpreted in the light of missing data and heterogeneity. The enthusiasm that early EN, as compared with early PN, would reduce mortality appears misplaced.

A review of the true methodological quality of nutritional support trials conducted in the critically ill: time for improvement

In this review we sought to appraise the true methodological quality of nutritional support studies conducted in critically ill patients and to compare these findings to the methodological quality of sepsis trials. An extensive literature search revealed 111 randomized controlled trials conducted in critically ill patients evaluating the impact of nutritional support interventions on clinically meaningful outcomes. Compared with sepsis trials, nutritional support studies were significantly less likely to use blinding (32 of 40 versus 35 of 111, P < 0.001) or present an intention-to-treat analysis (37 of 40 versus 64 of 111, P < 0.001). There was a trend toward the less frequent use of randomization methods that are known to maintain allocation concealment (12 of 40 versus 19 of 111, P = 0.10). Although nutritional support studies demonstrated a significant increase in the use of blinding after the publication of the CONSORT statement in 1996 (9 of 47 versus 26 of 64 post-CONSORT, P = 0.023), there were no improvements in other key areas. Previous publications have described the overall methodological quality of sepsis trials as "poor." Nutritional support studies were significantly worse than sepsis trials in all aspects of methodological quality, and there were few improvements noted over time. To detect important differences in clinically meaningful outcomes in critical care, the methodological quality of future studies must be improved.

Parenteral vs. enteral nutrition in the critically ill patient: a meta-analysis of trials using the intention to treat principle

OBJECTIVE

Controversy surrounds the use of parenteral nutrition in critical illness. Previous overviews used composite scales to identify high-quality trials, which may mask important differences in true methodological quality. Using a component-based approach this meta-analysis investigated the effect of trial quality on overall conclusions reached when standard enteral nutrition is compared to standard parenteral nutrition in critically ill patients.

METHODS

An extensive literature search was undertaken to identify all eligible trials. We retrieved 465 publications, and 11 qualified for inclusion. Nine trials presented complete follow-up, allowing the conduct of an intention to treat analysis.

RESULTS

Aggregation revealed a mortality benefit in favour of parenteral nutrition, with no heterogeneity. A priori specified subgroup analysis demonstrated the presence of a potentially important treatment-subgroup interaction between studies of parenteral vs. early enteral nutrition compared to parenteral vs. late enteral. Six trials with complete follow-up reported infectious complications. Infectious complications were increased with parenteral use. The I(2) measure of heterogeneity was 37.7%.

CONCLUSIONS

Intention to treat trials demonstrated reduced mortality associated with parenteral nutrition use. A priori subgroup analysis attributed this reduction to trials comparing parenteral to delayed enteral nutrition. Despite an association with increased infectious complications, a grade B+ evidence-based recommendation (level II trials, no heterogeneity) can be generated for parenteral nutrition use in patients in whom enteral nutrition cannot be initiated within 24 h of ICU admission or injury.

Effects of immunonutrition on intestinal mucosal apoptosis, mucosal atrophy, and bacterial translocation in head injured rats

BACKGROUND

Immunonutrition has been demonstrated to modulate gut function, reduce infectious complications, hospital stay, and ventilator days in the critical patients.

AIM OF THE STUDY

We assessed the effect of immunonutrition for the prevention of intestinal mucosal atrophy, apoptosis, and bacterial translocation in head injured rats.

METHODS

Thirty five rats were randomised into 5 groups. Following moderate closed head injury, in Group 1; Standard Enteral Nutrition, Group 2; Immunonutrition, Group 3; TPN, Group 4; pe. saline were applied. Group 5 was control group (chow-fed). The rats were sacrificed and segments of the ileum were removed for histologic examination, and samples of tissues taken for microbiologic evaluation.

RESULTS

Both intestinal apoptosis and mucosal atrophy were significantly lower in Group 2 and Group 5 (p<0.008). Bacterial translocation was significantly lower in Group 2 than Group 1 (p<0.008).

CONCLUSION

The enteral immunonutrition prevents intestinal barrier function in brain injured rats.

Catabolic response to stress and potential benefits of nutrition support

The catabolic response to sepsis, severe injury, and burn is characterized by whole-body protein loss, mainly reflecting increased breakdown of muscle proteins, in particular myofibrillar proteins. Glucocorticoids and various proinflammatory cytokines are important regulators of muscle proteolysis in stressed patients. There is evidence that breakdown of proteins by the ubiquitin-proteasome pathway plays an important role in muscle cachexia, although other mechanisms may participate, such as calcium- and calpain-dependent release of myofilaments from the sarcomere. Three types of treatments have been used to reduce or prevent the catabolic response to injury and sepsis: 1). nutritional, 2). hormonal, and 3). pharmacologic. With regard to nutrition support, it is generally believed that enteral feeding is superior to parenteral feeding and that early feeding is better than late feeding. Although "immune-enhancing" enteral nutrition has been shown in several recent studies to improve outcome in critically ill patients, the specific effects of these treatments on the catabolic response in muscle are not known. In addition to nutrition support, various hormones, including insulin, growth hormone, and insulin-like growth factor-1, may blunt the catabolic response in patients with stress. Experimental studies have indicated that other treatments may become available in the future, including cytokine antibodies, calcium antagonists, and induction of heat shock response. Methods to prevent or reduce the catabolic response to stress are important considering the significant clinical consequences of muscle cachexia.

Nutritional support after spinal cord injury

STANDARDS

There is insufficient evidence to support treatment standards.

GUIDELINES

There is insufficient evidence to support treatment guidelines.

OPTIONS

Nutritional support of patients with spinal cord injuries is recommended. Energy expenditure is best determined by indirect calorimetry in these patients because equation estimates of energy expenditure and subsequent caloric need tend to be inaccurate.

Ventilator-associated pneumonia. Prevention, diagnosis, and therapy

Ventilator-associated pneumonia remains the nosocomial ICU infection of greatest concern. The authors have summarized the clinical trials that have assessed specific strategies to prevent VAP and the current controversies regarding the diagnosis and therapeutic approach to this condition. Improvements in care of patients who are at risk for or who have developed VAP will depend on the judicious application of this information for individual patients.

Nutritional support for head-injured patients

BACKGROUND

Head injury increases the body's metabolic responses, and therefore nutritional demands. Provision of an adequate supply of nutrients is associated with improved outcome. The best route for administering nutrition (parenterally (TPN) or enterally (EN)), and the best timing of administration (e.g early versus late) of nutrients needs to be established.

OBJECTIVES

To quantify the effect on mortality and morbidity of alternative strategies of providing nutritional support following head injury.

SEARCH STRATEGY

Trials were identified by computerised searches of the Injuries Group specialised register, Cochrane Controlled Trials Register, MEDLINE, EMBASE and BIDS Index to Scientific and Technical Proceedings, and by checking the reference lists of trials and review articles.

SELECTION CRITERIA

Randomised controlled trials of timing or route of nutritional support following acute traumatic brain injury.

DATA COLLECTION AND ANALYSIS

Two reviewers independently abstracted data and assessed trial quality. Information was collected on death, disability, and incidence of infection. If trial quality was unclear, or if there were missing outcome data, trialists were contacted in an attempt to get further information.

MAIN RESULTS

The timing of support: early versus delayed Of the seven trials addressing the timing of support, data on mortality were obtained for all seven trials (284 participants). The relative risk (RR) for death with early nutritional support was 0.67 (95% CI 0.41 to 1.07). Data on disability were available for three trials. The RR for death or disability at the end of follow-up was 0.75 (0.50 to 1.11). The route of feeding: parenteral versus enteral Seven trials compared parenteral versus enteral nutrition. Because early support often involves parenteral nutrition, three of the trials are also included in the previous analyses. Five trials (207 participants) reported mortality. The RR for mortality at the end of follow-up period was 0.66 (0.41 to 1.07). Two trials provided data on death and disability. The RR was 0.69 (95%Cl 0.40 to 1.19). 3. Enteral nutrition: jejunal versus gastric. There was one trial with no deaths and the RR is not estimable.

REVIEWER'S CONCLUSIONS

This review suggests that early feeding may be associated with a trend towards better outcomes in terms of survival and disability. Further trials are required. These trials should report not only nutritional outcomes but also the effect on death and disability.

Parenteral nutrition in the critically-ill patient: more harm than good?

While many studies have reported that providing parenteral nutrition (PN) can change nutritional outcomes, there are limited data that demonstrate that PN influences clinically-important end points in critically-ill patients. The purpose of the present paper is to systematically review and critically appraise the literature to examine the relationship between PN and morbidity and mortality in the critically-ill patient. Studies comparing enteral nutrition (EN) with PN and studies comparing PN with no PN were reviewed. The results suggest that EN is associated with reduced infectious complications in some critically-ill subgroups. PN, on the other hand, is associated with increased morbidity and mortality in critically-ill patients. When nutritional support is indicated, EN should be used preferentially over PN. Further studies are needed to define the optimal timing and composition of PN in patients not tolerating sufficient EN. Strategies to optimize EN delivery and minimize PN utilization in critically-ill patients are indicated.

The metabolic response to acute traumatic brain injury and implications for nutritional support

An overview of the metabolic response to acute traumatic brain injury is presented. The consequences of hypermetabolism, hypercatabolism, and an altered immune function are discussed. Once a person with acute traumatic brain injury develops this hyperdynamic state, the resultant excessive protein breakdown ensues. This can lead to malnutrition. The feeding methods used to prevent malnutrition are discussed, along with the proper alimentation to provide to diminish the hyperdynamic state and improve immune function.

[Early enteral feeding in cranial trauma]

Until some years ago, patients suffering from head injury were poorly fed and nutrition was not a primary concern in the medical treatment of these patients. To date, six studies on head-injury patients have examined the effect of nutritional support on their outcome. All showed that lack of adequate nutrition contributed to increased mortality and morbidity. Head-injured patients on conventional enteral nutrition receive significantly less calories and proteins, resulting in an increased morbidity and mortality rate. Most of the severely head injured patients receiving enteral nutrition do not tolerate enteral feedings because of abnormal gastric emptying. The mechanisms of altered gastric function remain obscure. Increased intracranial pressure, cytokines, corticotropin-releasing factor, opiates, and other agents may all play a role. Impaired gastric motility has led to increasing use of small bowel feeding in head-injured patients. Jejunal feeding enables a higher caloric input and a better nitrogen balance. Moreover, it enables early enteral administration of nutrients in a safe and efficient way. Early administration of nutrients may be extremely important as it seems to decrease the hypermetabolic response to traumatic injury. Therefore, early jejunal enteral feeding may become an important cornerstone in the medical management of head-injured patients.

Nutritional support in the critically ill patients. A critical review of the evidence

Providing nutritional support has become a standard component of managing critically ill patients. While many studies have documented that providing nutritional support can change nutritional outcomes (e.g., amino acid profile, weight gain, nitrogen balance), data are lacking that demonstrate that nutrition actually influences clinically importance endpoints. This article systematically reviews and critically appraises the literature, examining the relationship between nutritional support and infectious morbidity and mortality in the critically ill patient. In addition, evidence-based recommendations are made.

Grains or veins: is enteral nutrition really better than parenteral nutrition? A look at the evidence

BACKGROUND

Enteral nutrition is said to be better than parenteral nutrition for providing nutrition support to humans.

PURPOSE

To assess the literature documenting the assertions that enteral nutrition is superior to parenteral nutrition with respect to cost, safety, physiology, intestinal structure and function, bacterial translocation, and outcome.

DATA IDENTIFICATION

Sources included MEDLINE search, personal files, and references from human comparative studies of enteral vs parenteral nutrition.

STUDY SELECTION

The goal was to include all human studies directly addressing questions of comparative efficacy of enteral and parenteral nutrition. Emphasis was given to prospective randomized controlled studies where available. Retrospective comparisons were not included.

DATA EXTRACTION

An attempt was made to briefly summarize methodology and findings of relevant studies. No general attempt was made to assess quality of individual studies.

RESULTS OF DATA SYNTHESIS

Enteral nutrition appears to be less expensive than parenteral nutrition, but new economic analyses are needed given the newer aggressive access techniques for enteral nutrition. Enteral nutrition is associated with meaningful morbidity and mortality. The little comparative data existent suggest no differences in safety. Comparative studies of physiology and metabolism as well as comparative and noncomparative studies of intestinal function and structure do not support putative advantages of enteral nutrition. There is no evidence that enteral nutrition prevents bacterial translocation in humans. Enteral nutrition probably reduces septic morbidity compared with parenteral nutrition in abdominal trauma. Otherwise, there is no evidence that enteral nutrition consistently improves patient outcome compared with parenteral nutrition.

CONCLUSIONS

With the exception of decreased cost and probable reduced septic morbidity in acute abdominal trauma, the available literature does not support the thesis that enteral nutrition is better than parenteral nutrition in humans.

Nutrition support in clinical practice: review of published data and recommendations for future research directions. National Institutes of Health, American Society for Parenteral and Enteral Nutrition, and American Society for Clinical Nutrition

In the last 30 years, marked advances in enteral feeding techniques, venous access, and enteral and parenteral nutrient formulations have made it possible to provide nutrition support to almost all patients. Despite the abundant medical literature and widespread use of nutritional therapy, many areas of nutrition support remain controversial. Therefore, the leadership at the National Institutes of Health, The American Society for Parenteral and Enteral Nutrition, and The American Society for Clinical Nutrition convened an advisory committee to perform a critical review of the current medical literature evaluating the clinical use of nutrition support; the goal was to assess our current body of knowledge and to identify the issues that deserve further investigation. The panel was divided into five groups to evaluate the following areas: nutrition assessment, nutrition support in patients with gastrointestinal diseases, nutrition support in wasting diseases, nutrition support in critically ill patients, and perioperative nutrition support. The findings from each group are summarized in this report. This document is not meant to establish practice guidelines for nutrition support. The use of nutritional therapy requires a careful integration of data from pertinent clinical trials, clinical expertise in the illness or injury being treated, clinical expertise in nutritional therapy, and input from the patient and his/her family.

The relation between nutrition and nosocomial pneumonia: randomized trials in critically ill patients

OBJECTIVE: To review the effect of enteral nutrition on nosocomial pneumonia in critically ill patients as summarized in randomized clinical trials. STUDY IDENTIFICATION AND SELECTION: Studies were identified through MEDLINE, SCISEARCH, EMBASE, the Cochrane Library, bibliographies of primary and review articles, and personal files. Through duplicate independent review, we selected randomized trials evaluating approaches to nutrition and their relation to nosocomial pneumonia. DATA ABSTRACTION: In duplicate, independently, we abstracted key data on the design features, population, intervention and outcomes of the studies. RESULTS: We identified four trials of enteral vs total parenteral nutrition, one trial of early enteral nutrition vs delayed enteral nutrition, one trial of gastric vs jejunal tube feeding, one trial of intermittent vs continuous enteral feeding, and three trials evaluating different enteral feeding formulae. Sample sizes were small, pneumonia definitions were variable and blinded outcome assessment was infrequent. Randomized trial evidence is insufficient to draw conclusions about the relation between enteral nutrition and nosocomial pneumonia. CONCLUSIONS: Nutritional interventions in critically ill patients appear to have a modest and inconsistent effect on nosocomial pneumonia. This body of evidence neither supports nor refutes the gastropulmonary route of infection.