ESPEN Guidelines on Enteral Nutrition: Intensive care

Adequação do suporte nutricional na terapia nutricional enteral: comparação em dois hospitais

OBJETIVO: Avaliar o estado nutricional de pacientes hospitalizados e comparar as condutas nutricionais enterais adotadas em dois hospitais gerais da região metropolitana de Maringá (PR), Brasil. MÉTODOS: O estudo foi realizado com 62 pacientes de ambos os sexos, em uso apenas de nutrição enteral. Os dados foram coletados em dois hospitais gerais. As necessidades energéticas dos pacientes foram calculadas por meio das equações propostas por Harris & Benedict e pela recomendação da European Society for Clinical Nutrition and Metabolism. O estado nutricional dos pacientes foi avaliado utilizando-se medidas antropométricas. RESULTADOS: Altos índices de desnutrição foram encontrados em ambos os hospitais, especialmente avaliando-se a Área Muscular do Braço. A prescrição energética mostrou-se adequada para 45,71% e 40,74% dos pacientes dos hospitais 1 e 2, respectivamente. CONCLUSÃO: Inadequações na terapia nutricional enteral, associadas a elevados índices de desnutrição, foram detectadas em ambos os hospitais. Os dados obtidos neste estudo demonstram a necessidade de melhoras nos dois serviços de nutrição enteral, sendo necessária a adoção de medidas de padronização e avaliação periódica dos pacientes.

[Enteral feeding of critical patients]

Artificial nutrition support forms part of the basic care of critical patients. Enteral feeding has been shown to be better than total parenteral nutrition at improving morbidity (infectious complications) and reducing the length of hospital stays, number of days with mechanical ventilation, and costs. As with any other treatment, enteral feeding has associated complications and side effects which should be understood and treated in order to obtain the greatest benefit from it and reduce possible adverse effects. In this review, we attempt to provide a practical summary of the use of enteral feeding in critical patients. We cover the management of the most frequent associated complications, based on new studies and current scientific evidence. The review is intended to serve as a practice guide for the routine care of severely ill patients.

To have and to hold nutritional control: balancing between individual and routine care. A grounded theory study

OBJECTIVES

Gaining insight into nutritional processes can help nurses and other staff in their work. The aim was to provide a theoretical understanding of the concerns and strategies of nutritional nursing care for patients with enteral nutrition in intensive care units.

DESIGN

A grounded theory approach was used. Observations of patient's nutritional care and twelve interviews with eight registered nurses and four enrolled nurses were conducted.

SETTING

The study was carried out in one intensive care unit at a medium sized hospital in Sweden.

RESULTS

The substantive theory developed included the core category "To have and to hold nutritional control - balancing between individual care and routine care". The core category was reflected in and related to the categories "knowing the patient", "facilitating the patient's involvement", "being a nurse in a team", "having professional confidence" and "having a supportive organisation". Finding a balance between individual care and routine care was a way of enhancing the patient's well-being, security and quality of care.

CONCLUSION

To have and to hold nutritional control over the patient's nutrition was found to be a balancing act between individual care and routine care. Organisation and teamwork are both challenging and supporting the provision, maintenance and development of nutritional care.

Clinical outcomes comparing parenteral and nasogastric tube nutrition after laryngeal and pharyngeal cancer surgery

Nasogastric tube-assisted enteral feeding and parenteral feeding are utilized for nutritional support after major surgery. Although these nutritional supports have been compared before, there have been no comparative trials following surgery for laryngeal and pharyngeal cancer. In this study, 81 patients were randomized to total parenteral nutrition (TPN) or nasogastric tube nutrition (NGTN) after laryngopharyngeal cancer surgery. The two groups were well-matched demographically and clinically. Clinical outcomes such as time of commencement of oral feeding and hospital stay and complications such as fistula were similar in both groups. One case in the TPN group had catheter-related sepsis, whereas aspiration pneumonia occurred in four cases (9.8%) in the NGTN group. The daily cost of NGTN was $11.81 cheaper than that of TPN. Subjective symptoms of nasal and pharyngeal discomfort and scores on subjective swallowing were more severe in the NGTN group within the first postoperative week but became similar thereafter. Although there was no difference in objective postoperative outcomes between both groups, these results imply that each method had particular advantages and disadvantages. Nutritional support after laryngopharyngeal cancer surgery should be determined after full consideration of each patient's conditions and surgical details along with economics.

Gastrointestinal complications in critically ill patients: what differs between adults and children?

PURPOSE OF REVIEW

The objective of this review has been to analyse and compare the causes, incidence, severity and treatment of gastrointestinal complications in critically ill children and adults.

RECENT FINDINGS

The incidence of gastrointestinal complications in critically ill patients published in the literature is very variable owing to the absence of unified diagnostic criteria both in children and adults. The incidence of gastrointestinal complications related to nutrition appears to be lower in children than in adults, and there are no differences in the incidence of gastrointestinal complications between gastric and transpyloric nutrition except with respect to the volume of gastric residues. The most important risk factors for digestive tract complications are shock and the administration of drugs (catecholamines, sedatives and muscle relaxants). Altered gastrointestinal motility is the principal mechanism underlying an excessive gastric residue, abdominal distension and constipation.

SUMMARY

Gastrointestinal complications limit the efficacy of enteral nutrition in the critically ill patient and can affect morbidity and mortality. Consensus must be reached on the definition of the criteria of excessive gastric residues, constipation and diarrhoea, and studies must be performed that evaluate the efficacy of prokinetic agents on altered gastrointestinal motility and the effects of diet and laxatives on constipation in the critically ill adult and child.

Caloric intake and liver dysfunction in critically ill patients

PURPOSE OF REVIEW

Despite increasing evidence that critically ill patients have lower energy requirements than expected, most guidelines continue to recommend elevated caloric requirements in these patients, particularly in septic patients. This practice leads to liver dysfunction when artificial nutrition is employed and worsens the prognosis of these patients. This review is focused on recent developments in the pathogenesis of artificial nutrition associated liver dysfunction in critically ill patients.

RECENT FINDINGS

The liver plays a pivotal role in managing nutritional substrates, and it is involved in the inflammatory response to injury and sepsis. The landmark phenomenon is insulin resistance and changes in the metabolic fates of glucose and fat. Glucose and lipids can act as toxics synergistically with inflammation to induce liver dysfunction. There are experimental evidences that insulin resistance in critically ill patients can share the same biochemical mechanisms and metabolic fates involved in insulin resistance of type 2 diabetes mellitus and metabolic syndrome. Furthermore, steatosis is also a common feature in both clinical pictures

SUMMARY

The pathogenesis of artificial nutrition associated with liver dysfunction is related to overfeeding and sepsis with a pathophysiology, similar to metabolic syndrome and type 2 diabetes. Changing nutritional strategies and adding new drugs will prevent, in part, liver dysfunction in these patients.

Antioxidant enriched enteral nutrition and oxidative stress after major gastrointestinal tract surgery

AIM: To investigate the effects of an enteral supple-ment containing antioxidants on circulating levels of antioxidants and indicators of oxidative stress after major gastrointestinal surgery.

METHODS: Twenty-one patients undergoing major upper gastrointestinal tract surgery were randomised in a single centre, open label study on the effect of postoperative enteral nutrition supplemented with antioxidants. The effect on circulating levels of antioxidants and indicators of oxidative stress, such as F2-isoprostane, was studied.

RESULTS: The antioxidant enteral supplement showed no adverse effects and was well tolerated. After surgery a decrease in the circulating levels of antioxidant parameters was observed. Only selenium and glutamine levels were restored to pre-operative values one week after surgery. F2-isoprostane increased in the first three postoperative days only in the antioxidant supplemented group. Lipopolysaccharide binding protein (LBP) levels decreased faster in the antioxidant group after surgery.

CONCLUSION: Despite lower antioxidant levels there was no increase in the circulating markers of oxidative stress on the first day after major abdominal surgery. The rise in F2-isoprostane in patients receiving the antioxidant supplement may be related to the conversion of antioxidants to oxidants which raises questions on antioxidant supplementation. Module AOX restored the postoperative decrease in selenium levels. The rapid decrease in LBP levels in the antioxidant group suggests a possible protective effect on gut wall integrity. Further studies are needed on the role of oxidative stress on outcome and the use of antioxidants in patients undergoing major abdominal surgery.

A systematic review on the timing of artificial nutrition in acute pancreatitis

Artificial nutrition is an inherent part of management in acute pancreatitis. However, there is no consensus regarding the optimal time of the commencement of feeding in these patients. Our aim was to compare the effect of enteral v. parenteral nutrition with regard to the time points when they were administered in the randomised controlled trials. The search was undertaken in the Cochrane Central Register of Controlled Trials, MEDLINE and Science Citation Index as well as in the proceedings of major gastroenterology meetings. The summary estimate of the effect associated with artificial nutrition was calculated using a random-effects model and presented as a risk ratio (RR) and 95 % CI. A total of eleven randomised controlled trials were included. When started within 48 h of admission, enteral nutrition, in comparison with parenteral nutrition, resulted in a statistically significant reduction in the risks of multiple organ failure (RR 0.44; 95 % CI 0.23, 0.84), pancreatic infectious complications (RR 0.46; 95 % CI 0.27, 0.77) and mortality (RR 0.46; 95 % CI 0.20, 0.99). After 48 h of admission, enteral nutrition, in comparison with parenteral nutrition, did not result in a statistically significant reduction in the risks of multiple organ failure (RR 0.73; 95 % CI 0.33, 1.63), pancreatic infectious complications (RR 0.31; 95 % CI 0.07, 1.34) and mortality (RR 0.67; 95 % CI 0.22, 2.10). Enteral nutrition is more effective than parenteral nutrition in reducing the risk of multiple organ failure, pancreatic infectious complications and mortality in patients with acute pancreatitis. The magnitude of these benefits may depend on the timing of the commencement of nutrition.

Enteral nutrition in the cardiothoracic intensive care unit: challenges and considerations

Cardiovascular disease is a common preexisting condition among hospitalized patients. Acute myocardial infarction and cardiac surgery account for 2 of the most common reasons patients are admitted to the intensive care unit. Determining how and when to feed these patients is a constant challenge presented to nutrition support practitioners. Enteral nutrition has emerged as the preferred route of feeding particularly in critical illness. By providing enteral nutrition instead of parenteral nutrition, the natural physiologic pathway is being followed and gut immunity preserved. However, obstacles such as upper gastrointestinal intolerance, hypoperfusion vasopressor support, and glycemic control make the task of initiating feeds a challenge. Once a patient has successfully tolerated feeds, the nutrition support clinician must still determine how much to feed and if specialty formulas such as those containing omega-3 fatty acids are beneficial for their patient. The purpose of this review is to present recent research on the feeding challenges in the critical care population with a focus on the cardiothoracic population and an emphasis on improving patient outcomes.

[Glycemic control in sepsis and septic shock: friend or foe?]

INTRODUCTION

Intensive care patients commonly suffer from hyperglycemia. Evidence is growing that strictly maintaining normoglycemia by intensive insulin therapy (IIT) ameliorates outcome in these patients. Whether or not this also holds true for patients with sepsis and septic shock is the issue of this post-hoc analysis of the database (2,748 patients) of 2 recent prospective clinical trials.

MATERIAL AND METHODS

A total of 950 patients suffering from sepsis were identified and of these 462 fulfilled the diagnostic criteria of septic shock upon admission to the intensive care unit (ICU). Patients were treated by either IIT [mean glycemia 5.88 mmol/l (106 mg/dl)] or conventional glucose management [mean glycemia 8.44 mmol/l (152 mg/dl)].

RESULTS

Under IIT the mortality of patients treated for more than 3 days in the ICU was lowered by 7.6% (p=0.03) in septic patients and by 8.7% (p=0.08) in septic shock patients. Polyneuropathy occurred less frequently under IIT compared to conventional glucose management (sepsis -9.8%, septic shock -14%; p<0.001). The incidence of acute renal failure was not affected by either treatment regimen (sepsis -3.3%, septic shock -3.1%; p<0.25). Intensive insulin therapy was associated with an increased risk of hypoglycemia (sepsis +16.7%, septic shock +18.8; p<0.0001) which did not, however, directly affect morbidity nor mortality.

CONCLUSIONS

These data suggest that IIT improves outcome of patients with sepsis or septic shock. Hypoglycemia is a frequent complication, but its clinical relevance remains to be defined.

Feeding the injured intestine: enteral nutrition in the critically ill patient

PURPOSE OF REVIEW

The utilization of enteral nutrition in critically ill patients is frequently suboptimal. This may be due, in part, to ongoing controversies regarding appropriate use of enteral support, but there are also perceived barriers to its use even when there is good evidence that it can be given. This review was undertaken to outline some of these controversies and barriers to use of enteral nutrition in the ICU.

RECENT FINDINGS

Although the advantages of enteral nutrition may have been overstated, it remains preferable to parenteral nutrition for support of critically ill patients. Early initiation of enteral support is a reasonable approach. Many patients with perceived contraindications to enteral therapy are actually good candidates for its use. Frequent interruptions in enteral nutrition lead to suboptimal nutrient delivery, but might be overcome by use of specific protocols emphasizing safe and effective utilization of enteral support.

SUMMARY

Use of enteral nutritional support is recommended for critically ill patients requiring specialized nutritional support. Barriers to its use could be overcome by better educating providers about indications for use and by developing methods to avoid undue interruption of therapy.

Enteral vs. parenteral nutrition for the critically ill patient: a combined support should be preferred

PURPOSE OF REVIEW

Current recommendations suggest starting enteral feeding as soon as possible whenever the gastrointestinal tract is functioning. The disadvantage of enteral support is that insufficient energy and protein coverage can occur. This review focuses on some recent findings regarding the nutritional support of critically ill patients and evaluates the data presented.

RECENT FINDINGS

An increasing nutritional deficit during a long ICU stay is associated with increased morbidity (infection rate, wound healing, mechanical ventilation, length of stay, duration of recovery), and costs. Evidence shows that enteral nutrition can result in underfeeding and that nutritional goals are frequently reached only after 1 week. Contrary to former beliefs, recent meta-analyses of ICU studies showed that parenteral nutrition is not related to a surplus mortality and may even be associated with improved survival.

SUMMARY

Early enteral nutrition is recommended for critically ill patients. Supplemental parenteral nutrition combined with enteral nutrition can be considered to cover the energy and protein targets when enteral nutrition alone fails to achieve the caloric goal. Whether such a combined nutritional support provides additional benefit on the overall outcome has to be proven in further studies on clinical outcome, including physical and cognitive functioning, quality of life, cost-effectiveness, and cost-utility.

Bench-to-bedside review: metabolism and nutrition

Acute kidney injury (AKI) develops mostly in the context of critical illness and multiple organ failure, characterized by alterations in substrate use, insulin resistance, and hypercatabolism. Optimal nutritional support of intensive care unit patients remains a matter of debate, mainly because of a lack of adequately designed clinical trials. Most guidelines are based on expert opinion rather than on solid evidence and are not fundamentally different for critically ill patients with or without AKI. In patients with a functional gastrointestinal tract, enteral nutrition is preferred over parenteral nutrition. The optimal timing of parenteral nutrition in those patients who cannot be fed enterally remains controversial. All nutritional regimens should include tight glycemic control. The recommended energy intake is 20 to 30 kcal/kg per day with a protein intake of 1.2 to 1.5 g/kg per day. Higher protein intakes have been suggested in patients with AKI on continuous renal replacement therapy (CRRT). However, the inadequate design of the trials does not allow firm conclusions. Nutritional support during CRRT should take into account the extracorporeal losses of glucose, amino acids, and micronutrients. Immunonutrients are the subject of intensive investigation but have not been evaluated specifically in patients with AKI. We suggest a protocolized nutritional strategy delivering enteral nutrition whenever possible and providing at least the daily requirements of trace elements and vitamins.

Nutrition support in the critically ill: a physician survey

BACKGROUND

Current clinical practice guidelines delineate optimal nutrition management in the intensive care unit (ICU) patient. In light of these existing data, the authors identify current physician perceptions of nutrition in critical illness, preferences relating to initiation of feeding, and management practices specific to nutrition after initiation of feeding in the ICU patient.

METHODS

The authors electronically distributed a 12-question survey to attending physicians, fellows, and residents who routinely admit patients to medical and surgical ICUs.

RESULTS

On a scale ranging from 1 to 5 (1 = low, 5 = high), the attending physician's mean rating for importance of nutrition in the ICU was 4.60, the rating for comfort level with the nutrition support at the authors' institution was 3.70, and the rating for the physician's own understanding of nutrition support in critically ill patients was 3.33. Attending physicians, fellows, and residents reported waiting an average of 2.43, 1.79, and 2.63 days, respectively, before addressing nutrition status in an ICU patient. Fifty-two percent of attending physicians chose parenteral nutrition as the preferred route of nutrition support in a patient with necrotizing pancreatitis. If a patient experiences enteral feeding intolerance, physicians most commonly would stop tube feeds. There was no significant difference in responses to any of the survey questions between attending physicians, fellows, and residents.

CONCLUSIONS

This study demonstrates a substantial discordance in physician perceptions and practice patterns regarding initiation and management of nutrition in ICU patients, indicating an urgent need for nutrition-related education at all levels of training.

Early nutritional therapy: the role of enteral and parenteral routes

PURPOSE OF REVIEW

Early nutrition is defined as the initiation of nutritional therapy within 48 h of either hospital admission or surgery. However, optimal timing for initiation of nutritional therapy through either enteral or parenteral routes remains poorly defined with the existing data. We reviewed the recent literature investigating the role of early enteral and parenteral nutrition in critical illness and perioperative care.

RECENT FINDINGS

Recent studies in both trauma/surgical and nonsurgical patients support the superiority of early enteral over early parenteral nutrition. However, late commencement of enteral feeding should be avoided if the gastrointestinal tract is functional. Both prolonged hypocaloric enteral feeding and hypercaloric parenteral nutrition should be avoided, although the precise caloric target remains controversial.

SUMMARY

Early enteral nutrition remains the first option for the critically ill patient. However, there seems to be increased favor for combined enteral-parenteral therapy in cases of sustained hypocaloric enteral nutrition. The key issue is when the dual regimen should be initiated. Although more study is required to determine the optimal timing to initiate a combined enteral-parenteral approach, enteral nutrition should be initiated early and parenteral nutrition added if caloric-protein targets cannot be achieved after a few days.

Pro/con debate: Is intensive insulin therapy targeting tight blood glucose control of benefit in critically ill patients?

You have decided to develop a protocol for insulin therapy in your intensive care unit (ICU). You wonder about the merit of using intensive insulin therapy (IIT) to maintain tight blood glucose control in your patients.

[Nasojejunal enteral feeding tubes in critically ill patients. Successful placement without technical assistance]

BACKGROUND

Critically ill patients with early enteral feeding seem to profit from post-pyloric administration. Two feeding tubes were studied that, due to their construction, are able to move into the duodenum without the necessity of technical support. The duration until successful positioning, time until total enteral feeding and possible complications were compared.

PATIENTS AND METHOD

Patients with naso-gastric tubes and early enteral feeding, who had an increased reflux despite head of bed elevation and prokinetic drugs, were randomly assigned to either a Tiger tube (Cook) or a Bengmark tube (Pfrimmer Nutricia).

RESULTS

A total of 28 patients from the surgical intensive care ward were included. Of the 16 Tiger tubes 14 could be successfully placed but only 2 out of the 12 Bengmark tubes. With Tiger tubes total enteral feeding was established within 6 days (median), with Bengmark tubes within 4 days.

CONCLUSION

In comparison to the Bengmark tube the Tiger tube has a higher success rate in terms of positioning in intensive care patients with impaired abdominal motility.

Preventing aspiration in older adults with dysphagia

Dysphagia, the impairment of any part of the swallowing process, increases the risk of aspiration. Dysphagia and aspiration are associated with the development of aspiration pneumonia. While some changes in swallowing may be a natural result of aging, dysphagia is especially prevalent among older adults with neurologic impairment or dementia, leading to an increased risk of aspiration and aspiration pneumonia. This article discusses best practices for assessment and prevention of aspiration among older adults who are being hand-fed or fed by tube. To view an accompanying online video, go to http://links.lww.com/A226.

Glutamine as a modulator of the immune system of critical care patients: effect on Toll-like receptor expression. A preliminary study

OBJECTIVE

We evaluated the expression of Toll-like receptors 2 and 4 (TLR-2 and TLR-4) in circulating monocytes from peripheral blood of critical care patients treated with and without glutamine. Because no research has been published to date on the effect of glutamine on TLR receptors in critical patients, it was determined in an initial sample of 30 patients.

METHODS

This was a prospective, randomized, single-blind study with 15 patients assigned to receive parenteral nutrition with a daily glutamine supplement of 0.35 g/kg. The control group received isocaloric-isonitrogenous parenteral nutrition. Blood samples were extracted before beginning the treatment and at 5 and 14 d. Expressions of CD14, TLR-2, and TLR-4 were determined by flow cytometry. Levels of TLRs were expressed as mean fluorescence intensity (mfi).

RESULTS

Basal characteristics were similar in both groups. The expressions of TLR-2 in the treatment group with glutamine were 4.67 +/- 3.82 mfi before treatment, 3.91 +/- 2.04 mfi at 5 d, and 4.28 +/- 2.47 mfi at 14 d. The expressions of TLR-2 in the control group were 5.49 +/- 3.20 mfi before treatment, 4.48 +/- 2.15 mfi at 5 d, and 4.36 +/- 2.36 mfi at 14 d. The expressions of TLR-4 in the treatment group were 1.65 +/- 1.89 mfi before treatment, 1.23 +/- 1.10 mfi at 5 d, and 1.77 +/- 1.97 at 14 d. The expressions of TLR-4 in the control group were 1.51 +/- 1.76 mfi before treatment, 1.36 +/- 0.99 mfi at 5 d, and 1.26 +/- 0.59 mfi at 14 d. Infections were detected in 11 patients who received glutamine and 13 control patients (P = 0.51).

CONCLUSION

In critical care patients, parenteral nutrition supplemented with glutamine does not increase the expression of TLR-2 or TLR-4 in peripheral blood monocytes.

Fish oil in critical illness

PURPOSE OF REVIEW

The aim of this review is to discuss recent advances in the role of n-3 lipids derived from fish oil in clinical nutrition in an intensive care setting.

RECENT FINDINGS

Fish oil supplies n-3 fatty acids which compete with arachidonic acid (n-6) for the conversion to lipid mediators, influence lipid-bound second messenger generation and dependent cellular functions, and are a source for resolvins necessary for the resolution of inflammation. Enteral nutrition with n-3 fatty acids improved ventilation time in patients with acute lung injury and in one study reduced mortality in septic patients. Using a high-dose short-term infusion of fish oil-based lipid emulsion, rapid immunologic changes and effects on the endotoxin-induced stress response may be achieved. Inclusion of n-3 fatty acids in parenteral nutrition improved immunologic parameters and length of stay in surgical patients.

SUMMARY

Inclusion of fish oil in nutrition may influence the immune response and clinical outcomes by balancing the negative effects of n-6 fatty acids. Application as a part of enteral immunonutrition in surgical or acute respiratory distress syndrome patients and in lipid emulsions in surgical patients has beneficial effects. In septic patients, data on enteral use are highly controversial. Prospective data from randomized trials, however, are lacking.

Early nutrition support in critical care: a European perspective

PURPOSE OF REVIEW

Today, early nutrition support is considered standard care in most ICUs. The recommended method is the enteral route, although there is only minor evidence for this. Often inadequate delivery of energy and a cumulative energy deficit are implied. The purpose of this paper is to evaluate the indication for early enteral nutrition or immunonutrition and to discuss the application of additional parenteral nutrition.

RECENT FINDINGS

The indication for early enteral nutrition is also supported by guidelines for enteral nutrition recently published by the European Society for Clinical Nutrition and Metabolism. Some more recent results strengthen the indication for a special formula in acute respiratory distress syndrome and septic patients. A recent metaanalysis has shown that parenteral nutrition is superior to delayed enteral nutrition. Additional parenteral nutrition thus seems to be the way to avoid cumulative energy deficit associated with insufficient or no enteral nutrition.

SUMMARY

Early enteral nutrition is recommended for critically ill patients, with special formulas indicated in specific subgroups of patients. If enteral nutrition is insufficient or fails, parenteral nutrition should be instituted, respecting the often reduced demand for exogenous substrates in critically ill patients.

Immunonutrition in surgical and critically ill patients

Surgery, trauma, burns and injury induce an inflammatory response that can become excessive and damaging in some patients. This hyperinflammation can be followed by an immunosuppressed state which increases susceptibility to infection. The resulting septic syndromes are associated with significant morbidity and mortality. A range of nutrients are able to modulate inflammation (and the associated oxidative stress) and to maintain or improve immune function. These include several amino acids, antioxidant vitamins and minerals, long-chain n-3 fatty acids and nucleotides. Experimental studies support a role for each of these nutrients in surgical, injured or critically ill patients. There is good evidence that glutamine influences immune function in such patients and that this is associated with clinical improvement. Evidence is also mounting for the use of long-chain n-3 fatty acids in surgical and septic patients, but more evidence of clinical efficacy is required. Mixtures of antioxidant vitamins and minerals are also clinically effective, especially if they include selenium. Their action appears not to involve improved immune function, although an anti-inflammatory mode of action has not been ruled out. Enteral immunonutrient mixtures, usually including arginine, nucleotides and long-chain n-3 fatty acids, have been used widely in surgical and critically ill patients. Evidence of efficacy is good in surgical patients. However whether these same mixtures are beneficial, or should even be used, in critically ill patients remains controversial, since some studies show increased mortality with such mixtures. There is a view that this is due to a high arginine content driving nitric oxide production.

Early enteral supplementation with key pharmaconutrients improves Sequential Organ Failure Assessment score in critically ill patients with sepsis: outcome of a randomized, controlled, double-blind trial

OBJECTIVE

To assess the safety and efficacy of an early enteral pharmaconutrition supplement containing glutamine dipeptides, antioxidative vitamins and trace elements, and butyrate in critically ill, septic patients.

DESIGN

A prospective, randomized, controlled, double-blind clinical trial.

SETTING

Adult intensive care unit in a university hospital.

PATIENTS

Fifty-five critically ill, septic patients requiring enteral feeding.

INTERVENTIONS

Patients received either an enteral supplement (500 mL of Intestamin, Fresenius Kabi) containing conditionally essential nutrients or a control solution via the nasogastric route for up to 10 days. Inclusion occurred within 24 hrs of intensive care unit admission. Additionally, patients received enteral feeding with an immunonutrition formula (experimental group) or standard formula (control group) initiated within 48 hrs after enrollment.

MEASUREMENTS AND MAIN RESULTS

Organ dysfunction was assessed by daily total Sequential Organ Failure Assessment (SOFA) score over the 10-day study period in both patient groups. Patients receiving the experimental supplement showed a significantly faster decline in the regression slopes of delta daily total SOFA score over time compared with control. The difference between the regression coefficients of the two slopes was significant irrespective of the level of analysis: intent to treat -0.32 vs. -0.14, p < .0001; per protocol -0.34 vs. -0.14, p < .0001; and completers (patients receiving > or = 80% of the calculated caloric target over a period of 6 days), -0.26 vs. -0.16, p = .0005. Vitamin C, as a marker of supplement absorption, increased from 10.6 (1.9-159.4) micromol/L (normal range 20-50 micromol/L) on day 1 to 58.7 (5.4-189.9) micromol/L by day 3 (p = .002) in the intervention group but remained below the normal range in the control group 17.0 (2.8-78.5) on day 1 and 14.3 (2.4-179.6) on day 3. Serum levels of glycine, serine, arginine, ornithine, vitamin E, and beta-carotene all increased significantly with treatment in the supplementation group.

CONCLUSIONS

In medical patients with sepsis, early enteral pharmaconutrition with glutamine dipeptides, vitamin C and E, beta-carotene, selenium, zinc, and butyrate in combination with an immunonutrition formula results in significantly faster recovery of organ function compared with control.

[Glutamine, an almost essential amino acid in the critically ill patient]

Glutamine is the most abundant amino acid in the human body and plays an important role in a number of metabolic pathways. Specifically, it is involved in amino acid and nucleotide synthesis, in the tricarboxylic acid cycle and in ureagenesis. Glutamine has been classified as a non-essential amino acid because the body can synthesize it, but under severe clinical conditions, the pool of glutamine is depleted and could be considered as conditionally essential. Low levels of glutamine are associated with a decrease in the immune response, changes in the structure and function of the intestinal mucose and the gut associated lymphoid tissue, a decreased anti-oxidant capacity and changes of the insulin sensitivity in critically ill patients. Administration of supplemental glutamine by enteral or parenteral route has produced controversial results. Most of the studies published support the hypothesis that glutamine can change the morbidity-mortality of the critically ill patients. There are unresolved questions related to the dose of glutamine and the best way to administer it, and particularly the subgroups of patients who will really benefit from this treatment.

[Nutrition of critically ill patients in intensive care]

A concept for combined enteral and parenteral nutrition for critically ill patients is described in which endogenous substrate production during the acute phase of illness is taken into consideration and hyperalimentation is avoided. The nutritional goal is defined by multiplication of the base rate, i.e. body weight (BW) in kg as delivery rate in ml/h (wedge 24 kcal/kg BW/24 h), with a target factor, which varies between 0.2 and 1.8. An equivalent composition of enteral and parenteral nutrition allows a transition between both forms without problems. Simultaneously, immunologic aspects of nutrition are considered as well and both forms of nutrition are complemented by immune-modulating substrates such as glutamine and antioxidants.

Evaluation of Delivery of Enteral Nutrition in Critically Ill Patients Receiving Mechanical Ventilation

Background Published reports consistently describe incomplete delivery of prescribed enteral nutrition. Which specific step in the process delays or interferes with the administration of a full dose of nutrients is unclear.

Objectives To assess factors associated with interruptions in enteral nutrition in critically ill patients receiving mechanical ventilation.

Methods An observational prospective study of 59 consecutive patients who required mechanical ventilation and were receiving enteral nutrition was done in an 18-bed medical intensive care unit of an academic center. Data were collected prospectively on standardized forms. Steps involved in the feeding process from admission to discharge were recorded, each step was timed, and delivery of nutrition was quantified.

Results Patients received approximately 50% (mean, 1106.3; SD, 885.9 Cal) of the prescribed caloric needs. Enteral nutrition was interrupted 27.3% of the available time. A mean of 1.13 interruptions occurred per patient per day; enteral nutrition was interrupted a mean of 6 (SD, 0.9) hours per patient each day. Prolonged interruptions were mainly associated with problems related to small-bore feeding tubes (25.5%), increased residual volumes (13.3%), weaning (11.7%), and other reasons (22.8%). Placement and confirmation of placement of the small-bore feeding tube were significant causes of incomplete delivery of nutrients on the day of admission.

Conclusions Delivery of enteral nutrition in critically ill patients receiving mechanical ventilation is interrupted by practices embedded in the care of these patients. Evaluation of the process reveals areas to improve the delivery of enteral nutrition.

Metabolic support in sepsis and multiple organ failure: more questions than answers

The metabolic support of critically ill patients is a relatively new topic of active research and discussion, and surprisingly little is known about the effects of critical illness on metabolic physiology and activity. The metabolic changes seen in critical illness are highly complex, and how and when to treat them are only just beginning to be determined. Studies have demonstrated that the acute phase and the later phase of critical illness behave differently from a metabolic point of view for many organs, and while many of the alterations in metabolism seen during early critical illness may be appropriate and beneficial responses to cellular stress, whether this is true for all the metabolic alterations in all forms of critical illness is unclear. Currently we face more questions than answers, and further study is needed to elucidate the various components of the metabolic response to acute and chronic critical illness and to develop better techniques to assess and monitor these changes so that we can determine which therapeutic approaches should be used in what combinations and in which patients.

Standardized concept for the treatment of gastrointestinal dysmotility in critically ill patients--current status and future options

Inhibition of gastrointestinal motility is a major problem in critically ill patients. Motor stasis gives rise to subsequent complications including intolerance to enteral feeding, enhanced permeability of the atrophic intestinal mucosa and conditions as severe as systemic inflammatory response syndrome, sepsis and multiple organ failure. Although the diagnosis of motility disturbances in critically ill patients is difficult, the type and site of the disturbance are important to consider in the analysis of the condition and in the choice of therapeutic approach. The pharmacological treatment of impaired gastrointestinal motility is difficult to handle for the clinician, because the underlying mechanisms are complex and not fully understood and the availability of pharmacological treatment options is limited. In addition, there is a lack of controlled studies on which to build an evidence-based treatment concept for critically ill patients. Notwithstanding this situation, there has been remarkable progress in the understanding of the integrated regulation of gastrointestinal motility in health and disease. These advances, which largely relate to the organization of the enteric nervous system and its signaling mechanisms, enable the intensivist to develop a standardized concept for the use of prokinetic agents in the treatment of impaired gastrointestinal motility in critically ill patients.

Protein and the critically ill; do we know what to give?

The National Institute for Health and Clinical Excellence (NICE) has recommended that nutrition support in seriously-ill or injured patients should start at 50% of the estimated target energy and protein needs. This recommendation has caused some concern, since taking the NICE approach leads to these sick individuals receiving an initial N provision of only 0.12 g N/kg per d, as opposed to levels of approximately 0.25 g N/kg per d that have been widely recommended by other expert groups. The basis of the recommendation for higher levels of N provision is that feeding at levels of >/=0.25 g N/kg per d reduces the inevitable net N loss of catabolism and hence minimises overall lean tissue wasting. However, although it has always been assumed that better N balance must equate with better outcome, there are teleological arguments that question the wisdom of providing more N to sicker patients and studies that imply that best N balance might not equate with best clinical progress. Furthermore, current evidence suggests that in most critical illness low initial intakes of both energy and N lead to improved survival. It therefore seems logical to aim, in the first instance, to feed the seriously ill at only modest levels. Further research is required to determine whether lower-energy higher-N feeding would prove better or worse than this approach in terms of clinical benefit rather than just better N retention. Investigations to explore the use of feeds that are specifically designed to match the amino acid needs of illness are also required.