The ESPEN guidelines represent the most comprehensive evaluation of enteral nutrition yet. They provide evidence based information on specific problems such as timing, dosing, composition and route of application
Professor Medizinische Klinik mit Schwerpunkt Gastroenterologie, Hepatologie and Endokrinologie Universitatsklinikum Charite
There is excellent evidence that undernutrition is an independent risk factor for higher morbidity, increased length of hospital stay, higher readmission rates, delayed recovery, lower quality of life, higher hospital costs and higher mortality. Similarly, the evidence on the effectiveness of nutritional support has grown considerably within the last decades. Therefore, the European Society for Clinical Nutrition and Metabolism (ESPEN) has published evidence-based guidelines for the use of enteral nutrition (EN) by means of oral nutritional supplementation (ONS) and tube feeding (TF) to evaluate benefits and risks of enteral nutrition in a predefined reproducible way.
The recommendations are focused on patients who develop a severe inflammatory response-that is, failure of at least one organ during ICU stay. EN should be given to all ICU patients not expected to be taking a full oral diet within 3 days. It should have begun during the first 24 h using a standard high-protein formula. During the acute and initial phases of critical illness an exogenous energy supply >20-25 kcal/kg BW/day should be avoided, whereas during recovery the aim should be to supply 25-30 total kcal/kg BW/day.
Supplementary parenteral nutrition remains a reserve tool and only for those who do not reach target nutrient intake on EN alone. There is no general indication for immune-modulating formulae in patients with severe illness or sepsis and APACHE II score >15. Glutamine should be supplemented in patients suffering from burns or trauma.
Surgery, including organ transplantation
Enhanced recovery of patients after surgery (‘ERAS’) has become an important focus. From a metabolic and nutritional point of view, key aspects include: avoidance of long periods of preoperative fasting; reestablishment of oral feeding as early as possible after surgery; integration of nutrition into the overall management of the patient; metabolic control (eg, of blood glucose); reduction of factors that exacerbate stressrelated catabolism or impair gastrointestinal function; early mobilisation.
EN is indicated even in patients without obvious undernutrition, if it is anticipated that the patient will be unable to eat for more than 7 days perioperatively. It is also indicated in patients who cannot maintain oral intake above 60% of recommended intake for more than 10 days. In these situations nutritional support
should be initiated without delay. Delay of surgery for preoperative EN is recommended for patients at severe nutritional risk, defined by the presence of at least one of the following criteria: weight loss >10-15% within 6 months, BMI< 18.5 kg/m2, Subjective Global Assessment Grade C, serum albumin <30 g/l (with no evidence of hepatic or renal dysfunction). Altogether, it is strongly recommended not to wait until severe undernutrition has developed, but to start EN therapy early, as soon as a nutritional risk becomes apparent.
Undernutrition and cachexia occur frequently in cancer patients and are indicators of poor prognosis. EN should be started if undernutrition already exists or if food intake is markedly reduced for more than 7-10 days. Standard formulae are recommended for EN. Nutritional needs generally are comparable to noncancer subjects. EN is indicated preoperatively for 5-7 days in cancer patients undergoing major abdominal surgery. During radiotherapy of head/neck and gastrointestinal regions dietary counselling and ONS prevent weight loss and interruption of radiotherapy. Routine EN is not
indicated during (high-dose) chemotherapy.
Undernutrition as well as specific nutrient deficiencies have been described in patients with Crohn’s disease (CD), ulcerative colitis (UC) and short bowel syndrome (SBS). ONS and/or TF in addition to normal food is indicated in undernourished patients with CD or CU to improve nutritional status. In active CD EN is the first-line therapy in children and should be used as sole therapy in adults mainly when treatment with corticosteroids is not feasible. No significant differences have been shown in the effects of free amino acid, peptidebased and whole protein formulae for TF. In remission ONS is recommended only in steroid-dependent CD patients. In SBS patients TF should be introduced inthe adaptation phase and should be changed with progressing adaptation to ONS in addition to normal food.
The two major forms of inflammatory pancreatic diseases, acute and chronic pancreatitis, require different approaches in nutritional management. In mild acute pancreatitis EN has no positive impact on the course of disease and is only recommended in patients who cannot consume normal food after 5-7 days. In severe necrotising pancreatitis EN is indicated and should be supplemented by parenteral nutrition if needed. In the majority of patients continuous TF with peptidebased formulae is possible. The jejunal route is recommended if gastric feeding is not tolerated. In chronic pancreatitis more than 80% of patients can be treated adequately with normal food supplemented by pancreatic enzymes. 10-15% of all patients require nutritional supplements, and in approximately 5% tube feeding is indicated.
EN by means of ONS is recommended for patients with chronic liver disease in whom undernutrition is very common. ONS improves nutritional status and survival in severely malnourished patients with alcoholic hepatitis. In patients with cirrhosis, TF improves nutritional status and liver function, reduces the rate of complications and prolongs survival. TF commenced early after liver transplantation can reduce complication rate and cost and is preferable to parenteral nutrition. In acute liver failure TF is feasible and used in the majority of patients.
Adult renal failure
EN is widely used in nephrology practice because of the nutritional impact of renal diseases. Patients with acute renal failure and critical illness are characterised by a highly catabolic state and need depurative techniques inducing massive nutrient loss. EN by TF is the preferred route for nutritional support in these patients. EN by means of ONS is the preferred way of refeeding for depleted conservatively treated chronic renal failure patients and dialysis patients. Undernutrition is an independent factor of survival in dialysis patients. ONS was shown to improve nutritional status in this setting. An increase in survival has been recently reported when nutritional status was improved by ONS.
Cardiology and pulmonology
No data are yet available concerning the effects of EN on cachexia in chronic heart failure patients. However, EN is recommended to stop or reverse weight loss on the basis of physiological plausibility. In patients with chronic obstructive pulmonary disease (COPD) EN in combination with exercise and anabolic pharmacotherapy has the potential to improve nutritional status and function. Frequent small amounts of ONS are preferred in order to avoid postprandial dyspnoea and satiety as well as to improve compliance.
Wasting in HIV/chronic diseases
Undernutrition (wasting) is still frequent in HIV-infected patients, despite recent decreases in the prevalence of undernutrition in western countries (as opposed to developing countries), due to the use of highly active antiretroviral treatment. Undernutrition has a negative prognostic effect independent of immunodeficiency and viral load. Nutritional therapy is indicated when significant weight loss (>5% in 3 months) or a significant loss of body cell mass (>5% in 3 months) has occurred, and should be considered when the body mass index is <18.5 kg/m2. If normal food intake including nutritional counselling and optimal use of ONS cannot achieve an adequate nutrient intake, TF with standard formulae is indicated. Due to conflicting results from studies on the impact of immune-modulating formulae, these are not generally recommended. The results obtained in HIV patients may be extrapolated to other chronic infectious diseases, in the absence of available data.
Nutritional intake is often compromised in elderly, multimorbid patients. EN by means of ONS is recommended for geriatric patients at nutritional risk in case of multimorbidity and frailty, and following orthopaedic surgery. In elderly people at risk of undernutrition ONS improves nutritional status and reduces mortality. After orthopaedic surgery ONS reduces unfavourable outcome. TF is clearly indicated in patients with neurologic dysphagia. In contrast, TF is not indicated in final disease states, including final dementia, and to facilitate patient care. It is strongly recommended not to wait until severe undernutrition has developed, but to start EN therapy early, as soon as a nutritional risk becomes apparent.
1. Valentini L, Schutz T, Allison S, Howard P, Pichard C,
Lochs H, editors. ESPEN Guidelines on Enteral Nutrition.
Clin Nutr 2006;25:177-360