Conference reports.

24th ESPEN (European Society of Parenteral & Enteral Nutrition) Congress

Patient's Progress--The Journey from Science to Practice, Glasgow, Scotland, 31 August--A September 2002

Almost 3000 delegates from around the world assembled in Glasgow for this conference concentrating on reviewing evidence and translating it into clinical practice.

The program was very intense, with four concurrent sessions running over most days. As usual ESPEN included an educational program throughout the conference. Five satellite symposia were run throughout the first three days and topics ranged from: disease-related malnutrition, ICU nutrition, immunonutrition in the surgical patient and management of cancer cachexia. There were 368 posters and on day four the 2002 BAPEN (British Association of Parenteral & Enteral Nutrition) Symposium on Intestinal Failure was held.

Malnutrition

Disease-related malnutrition: evidence-based approach to treatment, is a topic dear to the hearts of many dietitians. The two speakers were from the Institute of Human Nutrition, University of Southhampton, UK. Professor Marinos Elia presented a new conceptual framework for defining and treating malnutrition. He highlighted the confusion in its definition in terms of specific nutrients, cut-off values used and the type of individual and clinical circumstances to which it relates. He discussed the uncertainty relating to studies of prevalence because of variability according to assessment criteria used, location or setting of the study population and the disease type. Dr Stratton presented a systematic review of 287 trials and 11 720 patients to address the efficacy of nutritional support (oral supplementation and tube feeding). In order to provide specific insights that could be generalised into the use of nutritional support, a multi-layered approach to establishing the evidence was undertaken. This ranged f rom consideration of individual randomised controls (RCTs) and non-RCTs according to patient group, intervention type and setting to a summary and meta-analysis of all studies. Separate and combined analysis of oral supplementation and tube feeding studies showed significant benefits on mortality, complications and length of stay in hospital in high nutritional risk individuals compared with routine clinical care (usually diet as tolerated and/or food fortification). For those interested in this study the investigators have written a book (1).

Management of cancer cachexia

Cancer cachexia is a complex scenario resulting not only from a reduced nutrient intake, but also from the metabolic effects associated with the tumour and its associated treatment (surgery, chemotherapy, radiotherapy or hormonal treatment). The question posed was: How effective is nutritional support alone in reversing these metabolic derangements? Initial voting by the audience accepted that nutritional support had a role in reducing morbidity in high nutritional risk patients but most were unclear of its benefits on mortality. They were also unclear as to the role of drugs and nutraceuticals in this process.

Professor Ken Fearon from Edinburgh, UK, argued that cancer cachexia is not just weight loss which is why studies of nutritional support alone have shown limited benefits on functional outcome. Any weight gain that has been observed particularly in the intravenously fed patient tended to be fat and fluid. He stated the need to correct the metabolic abnormalities as well as providing nutrients and presented data from a prospective study to show a dose-dependent attenuation of weight loss and simultaneous gain in lean body mass in advanced pancreatic cancer patients given eicosapentanoic acid in a high protein, high energy supplement called Prosure (Abbott Australasia Pty Ltd). Professor Fearon dismissed the drug approach to metabolic manipulation because of the significant side effects.

Conversely, Professor Kent Lundholm from Gothenburg, Sweden, argued there was no evidence to suggest that nutraceuticals could affect the neuro-endocrine stress response. He acknowledged the literature did not provide convincing evidence for nutritional support alone in the treatment of advanced cancer patients and presented evidence from his randomised control trials that the use of a multimodal approach (including anaemia correction, anti-inflammatory treatment plus nutritional support) offered a significant means to improve survival. The debate, however, was won by Fearon.

Modulation of the acute phase response

Professor Obled from France provided an overview of the acute phase response including the mediators produced and their consequent metabolic effects; she highlighted the importance of this response in host survival. However, in cases where this response became over-activated there was an increased risk of poor outcome. Various treatments including the use of anti-cytokines, anabolic agents and neutraceuticals have been used to modulate this response with varying results. Professor Alan Shenkin from Liverpool, UK, asked if we should be attempting to modulate this response at all and that as it has evolved over millennia it would be for a good reason. The increase in metabolic rate increases temperature, which enhances enzyme activity; tissue mobilisation provides fuel for injured tissue and substrates for the production of a range of acute phase proteins; iron is sequestered to inhibit bacterial growth; and zinc for increased hepatic protein synthesis. In a well-nourished individual the magnitude of the respon se is generally well balanced with the magnitude of the insult and is self-resolving due to a complex interplay between pro-inflammatory and compensatory anti-inflammatory responses. Poor outcomes can be seen in (a) major trauma: where the pro-inflammatory response becomes over-activated; (b) malnutrition: where the acute phase response overall is suboptimal; and (c) where there is too much of a compensatory response through treatment effects. Thus in any medical intervention to modulate this response the balance is critical between harmful and helpful effects.

Dr Michel Gassul from Barcelona, Spain, spoke on the use of dietary lipids in the management of inflammatory bowel disease. The sustained release of inflammatory cytokines cannot be dowaregulated with drugs without side-effects. His group has been testing the effects of formulae with fish oils and olive oil on Crohns disease. They have found olive oil is most effective in promoting remission. The effect is not seen with synthetic oleic acid. Thus the non-fatty acid component may be responsible. The proposed mechanism is by increased apoptosis.

Immunonutrition in elective surgery--A call for action

Dr Bob Martindale from Augusta, USA, provided an overview of the US Summit on Immune-Enhancing Enteral Therapy, held in May 2000. The objectives of the consensus panel were to critically review research and make recommendations on: the types of patients who would most benefit from immune modulating formulas, when therapy should be commenced, optimal dosing and duration of treatment, expected outcomes and measures of outcomes. The consensus recommendations were published in 2001 (2). In brief, the recommendations are divided into three groups: those expected to benefit from these formulas, those who should benefit but the evidence is insufficient to make recommendations and those patients felt not to be candidates for immunonutrition. He concluded by saying the future challenges for this area included defining the correct 'mix' of immune modulating nutrients, better definition of target populations and increasing the understanding of any potential adverse effects.

Professor Marco Braga from Milan, Italy, presented data to support the benefit of using immune-modulating formulas in upper gastrointestinal surgery. He concluded that the evidence showed immunonutrition improves outcome in patients undergoing major surgery for cancer, ii malnourished patients a dose-dependent effect of key nutrients on outcome was observed and in well nourished patients preoperative immunonutrition was equally as effective as pen-operative treatment.

Dr Nuria Farreras from Barcelona, Spain, presented her data from a randomised control trial looking at the effect of an immune modulating formulation on wound healing in patients undergoing surgery for gastric cancer. The study showed a reduction in overall morbidity, infectious complication rates, length of hospital stay and improved wound healing as shown by increased collagen synthesis rates. In summarising the session, Bob Martindale concluded that: the data support the use of immunonutrition in select surgical populations; it is safe when used appropriately however, the perfect mix of immunomodulatory nutrients remains elusive. Immunosuppressive regimens (e.g. excessive parenteral n-6 fats and overfeeding) should be avoided, there is a need to be meticulous with post-stress glycaemic control and the key nutrients appear to be arginine, glutamine, n-3 fats and nucleotides. The future for clinical immunomodulation includes the use of pre-probiotics, phytochemicals and antioxidants.

Nutrition, metabolism and ageing

Dr R Roubenoff from the USA provided an excellent overview of the acute phase response and lean tissue depletion associated with the ageing process. Age-related sarcopenia is the result of a reduction in muscle mass and quality (type II muscle fibres), leading to a reduced ability to respond to anabolic stimulii. The cause is multifactorial and includes altered hormone levels, chronic oxidative stress, insulin resistance, chronic subclinical inflammatory responses and increased inactivity. It is possible to somewhat reverse this process with regular weight-bearing exercise and/or exogenous anabolic hormones.

Dr Susan Schiffman of Duke University, USA, discussed ways ageing, medications and disease impact on chemosensitivity (taste and smell). Distortions of taste and smell are common in the elderly and represent a serious risk factor for nutritional and immune deficiencies. Dr Schiffinan's work showed that enhancing the flavour of foods increased oral intake of meals resulting in weight gain/or maintenance, enhanced immune status, improved digestion and greater muscle strength (measured by hand grip strength).

Critical care nutrition

A satellite symposium discussed the age-old question of early enteral nutrition. Bob Martindale, a US gastrointestinal surgeon, discussed the pros and cons of enteral nutrition. He began by commenting that nutrition is only one of a number of medical treatments that determine outcome in this patient population. The advantages of early enteral nutrition must be used with caution due to associated complications such as jejunal necrosis. He suggested that maybe the pendulum for enteral nutrition has swung too far. The evolving consensus for nutritional support of the critically ill patient is that of dual feeding, with enteral feeding providing mucosal protection and parenteral nutrition making up the energy deficit.

Professor Hans Biesalski from Germany, noted that there is good evidence from experimental and clinical studies that trauma and injury result in an imbalance in the antioxidant system due to the increased production of reactive oxygen species. These result in an increase in complications such as sepsis, acute respiratory distress syndrome and multi-organ failure. Supplementation with antioxidants as early as possible should have beneficial effects. What remains unknown however are the optimum levels of these nutrients, as for some there is a narrow margin between therapeutic and toxic levels.

Perioperative nutritional care

Jonas Nygren from Ersta Hospital, Stockholm, Sweden, has been involved in investigating how nutrition can be involved in accelerating recovery from surgery. He presented some preliminary collaborative work where preoperative-CHO loading has been incorporated into a multimodal approach to managing the elective cob-rectal surgical patient. This included preoperative information, use of short acting or nil pre-anaesthetic medication, regional anaesthesia, minimal invasive surgery, early removal of nasogastric tubes and urinary catheters, judicious restriction of post-operative intravenous saline, post-operative epidural anaesthesia and laxatives, early mobilisation and early post-operative nutrition. The results for 100 consecutive patients are encouraging in reducing length of stay. A larger multicentre European study is currently underway.

Intestinal failure (2002 BAPEN Symposium)

ESPEN concluded with a comprehensive review of the medical and surgical management of intestinal failure. This was defined as a reduction in functioning gut mass below the minimal amount necessary for adequate digestion and absorption of food, fluids and electrolytes. There are three types. Type 1 is self limiting, short term (< 3 weeks), type 2 is short to medium term (weeks to months) and type 3 is long term. The type of nutritional support depends on the severity of the failure in terms of the amount and location of gut affected. This may range from use of oral rehydration solutions to therapeutic diets, to meticulously well located feeding tubes to home parenteral nutrition. Much was mentioned on the judicious use of IV saline to prevent delayed gastrointenstinal recovery (3); modification of macronutrient composition of the enteral diet depending on whether the colon was present; and the composition of oral rehydration solutions depending on whether the patient was a net secretor or absorber.

The necessary use of adjuvant drug therapy was also discussed including the use of acid suppression drugs, antidiarrheoals, hormones and growth factors. The surgical management of intestinal failure was outlined with emphasis on the need to manage sepsis before nutrition support, though some consider nutrition is an integral component of the management of sepsis and should occur concurrently. The final lecture I attended was by a surgeon who discussed intestinal transplantation. This has always been a difficult procedure to undertake because of the great demand for immunosuppressive therapy. Outcome data have always been poor but results are improving. The costs remain a huge obstacle.

The final keynote lecture for ESPEN presented the ability now available to recreate an entire bowel from tissue culture obviating the need for the transplant surgeon.

Alan Spencer

Director of Nutrition

Gold Coast Hospital

Southport, Queensland

Financial assistance to attend this conference was provided by Nutricia Australia Pty Ltd in return for presenting this report. For an extended report see www.novartisnutrition.com.au.

A comprehensive review of the congress was published in Clinical Nutrition 2002;2l Suppl:1S-175S.

References

(1.) Stratton RJ, Green CJ, Elia M. Disease-related malnutrition: an evidence-based approach to treatment. Wallingford: CAB International; 2002.

(2.) Proceedings from Summit on Immune Enhancing Enteral Therapy, 25-26 May 2000, San Diego, Califorina. JPEN 2001;25 Suppl:1-62.

(3.) Lobo DN, Bostock KA, Neal KR, Perkins AC, Rowlands BJ, Allison SP. Avoidance of excess saline administration postoperatively allows earlier recovery of gastrointestinal function, reduces complications and shortens postoperative stay: A prospective randomised controlled study. British Journal of Surgery 2001;88 Suppl:25-6.