Unnecessary care defined as "services which show no demonstrable benefit to patients", should be avoided whenever possible. However, the threshold between necessity and lack thereof is often subjective, especially in the domain of nutrition, as the costs of underfeeding remain unrecognized in the majority of hospitals. Artificial nutrition and particularly parenteral nutrition (PN) have been criticized in the context of budget cuts: the administrators only look at the purchase costs of the PN solutions and micronutrients, and compare then with equivalent doses of enteral nutrition (EN), but do never include the prevented infections in the equation. The administrators are generally not aware of the relative inefficiency of EN to cover needs, and the underfeeding/malnutrition consequences that have a high cost [1,2]. PN is also considered to have a high potential to overfeed, which may indeed be deleterious. It is important to recognize that both under and overfeeding cause complications.
Underfeeding contributes to loss of lean body mass (LBM), an important determinant of outcome. When LBM is lost it contributes to reduction of the quality of life after discharge. Considering that many patients are admitted in poor condition, the additional burden of acute underfeeding will only worsen outcome. Some trials have now demonstrated that increasing the dose of proteins, and the use of combined feeding results in improved immunity, less infections, better muscle strength, and lower costs [3-6]. Adapted feeding may actually get the patients home , which is an absolute cost reduction.
To show their goodwill, several ICU societies have included PN among the strategies to ban as they were considered to “generate unnecessary costs”. The Swiss ICU society adopted the ASPEN formulation: the Swiss nutrition society discussed this point of view, and a reformulation of the recommendation was realized. Choosing wisely is a call for quality, for individualized feeding, adapted to the phase of disease, with measurements of energy goals using indirect calorimetry, and monitoring the response to feeding. But to be really wise, these recommendations must integrate all aspects.
1) Doig GS et al, Dovepress 2013 ;5 :369, 2) Pradelli L et al Clin Nutr 2018 ;37 :573, 3) Ferrie S et al. JPEN. 2016;40:795, 4) Weijs PJM et al. J Clin Med 2019;8:43, 5) Heidegger CP et al. Lancet 2013;381:385, 6) Berger MM et al; Clin nutr 2018, e-pub. 7) Yeh et al JPEN 2016; 40:37
Trials conducted over the last 10 years have generated an intense debate, and confusion for the clinicians. The ESPEN guidelines aim at reconciling different concepts. It emphasizes the role of evaluation the patient’s nutritional status, using the simple NRS-2002-score. Thereafter, the importance of timing of the intervention is stressed, as patients evolve over time. The early acute phase (48-72 hours) is characterized by hemodynamic, respiratory and metabolic instability, with associated high risk of electrolyte shifts (phosphate, refeeding), gut dysfunction, and simultaneous important endogenous glucose production covering 50-70% of energy expenditure. The 2nd part of the acute phase (@1st week) is characterized by continued catabolism, frequent hypermetabolism, but stabilization of organ dysfunction, enabling nutrition to cover 90-100% of measured goals. The guidelines recommend using indirect calorimetry at this stage to prescribe energy targets, and not to use equations which are wrong and often favor overfeeding.
In patients unable to cover their needs orally, the preferential feeding strategy remains enteral nutrition (EN). But it is important not to let the patients for more than 3 days without any balanced nutrition: when the EN is insufficient to cover 60% of needs, parenteral nutrition (PN) is then recommended (alone or combined) after day 3. Indeed while recommending using the intestine for EN as early as possible, progression may not be possible: forcing the gut may results in severe complications, and should not be done.
Substrates and particularly proteins require special attention: unbalance substrate provisions, i.e. provision of only glucose or lipids (propofol) is strongly discouraged. A goal of 1.3 g/kg/day proteins is recommended, to be achieved as early as possible. Energy and proteins goals should be considered separately, which means giving special attention to the products used in the ICU. Lipid solutions should be balanced, and include all fatty acids, including omega-3 fatty acids. Special attention should be given to micronutrients especially in case of PN, as the feeding solutions do not contain it. High dose single micronutrient therapy is not recommended. Finally the feed delivery and the response to feeding should be systematically monitored (separate document): under- and over-feeding should both be avoided.