Tailoring nutrition therapy to illness and recovery

Abstract

Without doubt, in medicine as in life, one size does not fit all. We do not administer the same drug or dose to every patient at all times, so why then would we live under the illusion that we should give the same nutrition at all times in the continuum of critical illness? We have long lived under the assumption that critical illness and trauma lead to a consistent early increase in metabolic/caloric need, the so-called “hypermetabolism” of critical illness. What if this is incorrect? Recent data indicate that early underfeeding of calories (trophic feeding) may have benefits and may require consideration in well-nourished patients. However, we must confront the reality that currently ICU nutrition delivery worldwide is actually leading to “starvation” of our patients and is likely a major contributor to poor long-term quality of life outcomes. To begin to ascertain the actual calorie and protein delivery required for optimal ICU recovery, an understanding of “starvation” and recovery from starvation and lean body mass (LBM) loss is needed. To begin to answer this question, we must look to the landmark Minnesota Starvation Study from 1945. This trial defines much of the world’s knowledge about starvation, and most importantly what is required for recovery from starvation and massive LBM loss as occurs in the ICU. Recent and historic data indicate that critical illness is characterized by early massive catabolism, LBM loss, and escalating hypermetabolism that can persist for months or years. Early enteral nutrition during the acute phase should attempt to correct micronutrient/vitamin deficiencies, deliver adequate protein, and moderate nonprotein calories in well-nourished patients, as in the acute phase they are capable of generating significant endogenous energy. Post resuscitation, increasing protein (1.5–2.0 g/kg/day) and calories are needed to attenuate LBM loss and promote recovery. Malnutrition screening is essential and parenteral nutrition can be safely added following resuscitation when enteral nutrition is failing based on pre-illness malnutrition and LBM status. Following the ICU stay, significant protein/calorie delivery for months or years is required to facilitate functional and LBM recovery, with high-protein oral supplements being essential to achieve adequate nutrition.

Full Nutrition or Not?

“…If we underfeed in the first week, do we need to overcome the caloric debt? Will there be deleterious effects to patients? There is clinical evidence to suggest targeting caloric debt as an endpoint for nutrition delivery as an effective strategy …”

“…Will there be deleterious effects to patients? 10 There is clinical evidence to suggest targeting caloric debt as an endpoint for nutrition delivery as an effective strategy. 11 The recent NUTRIREA-2 study points to a potential signal of harm from full feeding, in particular because of gastrointestinal complications, particularly ischemia.…”

Nutrition therapy in critical illness: a review of the literature for clinicians

“…However, trial findings and guideline recommendations continue to be conflicting, making the translation of evidence into practice challenging. Further, it is becoming evident that the stage of critical illness and individual factors such as body composition may be important when considering how individuals might respond to nutrition interventions [3,4]. This narrative review aims to provide a summary and interpretation of the adult critical care nutrition literature, with a particular focus on continuing practice gaps and areas with new data, to help clinicians make practical, yet evidencebased decisions regarding nutrition management during critical illness.…”

“…The metabolic response to critical illness and the role of nutrition therapy It is recognised that 'one-size fits all' and 'set and forget' approaches to nutrition do not adequately address the complex metabolic, hormonal, and immunological changes that occur with critical illness [3,5]. It is essential that clinicians understand these processes and the impact on nutrient metabolism [4].…”

“…The 'flow' phase involves the breakdown of tissue (including lean muscle tissue) in order to provide substrates to cover the immediate needs for the 'fight or flight' response and to reduce the risk of bleeding and infection [4]. More recently, a third, anabolic recovery phase has been described [3]. It is during this recovery phase when resynthesis of lost tissue can take place and the body may be more metabolically able to process delivered nutrients [3,4].…”