EDITORIAL URRENT C OPINION
Chronic critical illness nutritional requirements: more, less, or just different? Jeffrey I. Mechanick and Mette M. Berger
The miracle of ICU medical knowledge and technology has created the ‘chronic critical illness’ (CCI) syndrome and consequently, a host of novel and recycled derivative questions [1]. Regardless of the precise definition, CCI patients have survived their acute insult and interventions, and have generally been treated a few weeks in the ICU. Prior questions about early feeding and tight glycemic control targets are rendered moot, as the pathophysiology and metabolic imperatives of the new CCI state take priority. For the purpose of this brief commentary, let us view CCI as simply a state of prolonged critical illness and stipulate that the pathophysiology still needs unraveling. We have invited authors to address the various facets of this problem, but first, here are the questions, which can then be applied to CCI: (1) (2) (3) (4)
What physiopathology favors enteral nutrition? How should total energy delivery be adjusted? How should nitrogen requirements be adjusted? What is the role for nutritional pharmacology and adjuvant metabolic control? (5) What is a rational approach based on our knowledge, experience, and evidence base to integrate and apply the above answers? The nutrition support route question is addressed in the context of gut mucosal immunity by Fukatsu (pp. 164–170). This has been the source of much debate, and the author makes a crisp argument that enteral nutrition should be provided early and as consistently as possible to prevent impairment of gut mucosal function. The immune consequence of this function is important – a portion of the sensitized lymphocytes in the gutassociated lymphoid tissue that is stimulated by enteral feeds home to extraintestinal mucosal sites such as the respiratory tract, and thereby contribute to the mucosal defense. Corollaries to this conclusion are that combined enteral nutrition and parenteral nutrition and enteral nutrition surrogates, such as glutamine, may offer benefit of patients. CCI patients may derive particular benefit from this strategy. www.co-clinicalnutrition.com
The total energy question is addressed in the article by Guttormsen and Pichard (pp. 171–176), in which at the present time target amounts that cannot be determined through formulaic or modeled computations. Instead, the authors argue – and this approach has been validated in the recent studies [2,3] – that indirect calorimetry should be performed routinely and on a regular basis as individual energy requirements vary greatly. The major obstacle, however, is cost and acceptance of indirect calorimetry as a standard practice, especially with serial measurements during CCI when metabolic set points are dynamic in nature. This is the basis for two European societies (European Society of Clinical Nutrition and European Society of Intensive Care) supporting a 2014 multicenter research project promoting the development of a cheap, reliable indirect calorimeter for use in the ICU [4]. The nitrogen requirement question is addressed by Weijs (pp. 183–189). During the acute critical illness stage, guidelines recommend that early and sufficient protein feeding that is 1.3–1.5 g/kg/day be delivered and energy intake be informed by indirect calorimetry measurements. However, there are still very poor metrics for CCI nitrogen provision, and therefore an emphasis on safety is warranted. Hence, recommendations will continue to be impressionistic with CCI. This translates into a mandate for relevant nutrition support trials specifically in the CCI population, who are high-risk patients. The role of carnitine as an example of acute lifethreatening deficiencies is addressed by Bonafe´ et al. (pp. 200–209). Carnitine deficiency is probably under-recognized in CCI, and supplementation should be considered in high-risk patients. This is Division of Endocrinology, Diabetes and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, New York, USA Correspondence to Mette M. Berger, MD, PhD, Service de Me´decine Intensive Adulte et Centre des Bruˆle´s, Lausanne University Hospital CHUV, Rue du Bugnon 46, CH – 1011 Lausanne, Switzerland. Tel: +41 21 31 42 095; fax: +41 21 31 43 045; e-mail: [email protected] Curr Opin Clin Nutr Metab Care 2014, 17:162–163 DOI:10.1097/MCO.0000000000000040 Volume 17 Number 2 March 2014
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Chronic critical illness nutritional requirements Mechanick and Berger
a concept that requires further investigation particularly in patients who benefit from prolonged renal replacement therapy, which in addition to eliminating wishful ‘toxins’ causes manifold loss of water soluble micronutrients, such as trace elements and glutamine [5]. This precipitates metabolic and infectious complications. Unfortunately, the clinical evidence base is quite sparse, and any routine practice or stronger recommendation will need to await higher levels of scientific substantiation. The role of metabolic control is addressed by Okabayashi (pp. 190–199) with respect to intensive insulin therapy. As the initial Leuven protocol [6] triggered a resurgence of interest in ICU metabolic support, it has become clear that one cannot directly extrapolate highly controlled experimental findings to multisetting, complex, real-life scenarios. For years, we have emphasized that research studies need to address the specific clinical questions, and as advanced technology advances, the answers will also evolve. Closed-loop glycemic control systems must be evaluated in diverse complex settings to be pragmatic. Issues, such as glycemic variability, nature of nutrition support, and ICU logistics will all need to be incorporated. The role of a comprehensive approach is partially addressed by Kondrup (pp. 177–182) on nutritional risk scoring and clinical decisionmaking, especially for parenteral nutrition. As there are still no generally accepted and validated scoring systems to risk-stratify metabolic interventions for critical illness, the authors argue that, for now, decisions should be based on the severity of nutritional risk and the duration of underfeeding observed. Granted, this is rather simplified, but the message here, especially for CCI patients, is that dedicated studies focusing on approach (i.e., a specific decision algorithm) may be more important than a conventional single-intervention trial. Taken together, one can extrapolate many of these concepts to the CCI state, and fashion an approach wherein every ICU patient is risk stratified, enteral nutrition prioritized but parenteral nutrition used to ensure adequate total energy
and nitrogen, metabolic control parameters set using safe technology, and nutritional pharmacological agents applied judiciously. There are still no hard recommendations. However, we foresee an eventual personalized metabolic care plan for CCI patients that now can be based on an emerging body of information derived, not from purely academic research topics, but rather from practical research questions and Bayesian clinical trials. As coeditors, this will be our sixth and last issue of working together on Current Opinion’s Nutrition and the ICU. Although we have been vexed by incessant controversy, we marvel at the great progress made in studying real-life clinical ICU questions, especially for those with CCI. We are optimistic that where nutrition had been generally relegated to supportive and adjuvant care, it is now frequently recognized on rounds as a primary intervention, hashed out with greater zeal, scientific evidence, and action. So, for now, how would you describe CCI metabolic care compared with acute ICU care: ‘different... more or less’. Acknowledgements None. Conflicts of interest There are no conflicts of interest.
REFERENCES 1.
2.
3.
4.
5.
6.
1363-1950 ß 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins
Schulman RC, Mechanick JI. Can nutrition support interfere with recovery from acute critical illness? In: Singer P, editor. Nutrition in intensive care medicine: Beyond physiology. Basel 2013. Heidegger CP, Berger MM, Graf S, et al. Optimisation of energy provision with supplemental parenteral nutrition in critically ill patients: a randomised controlled clinical trial. Lancet 2013; 381:385–393. Singer P, Anbar R, Cohen J, et al. The tight calorie control study (TICACOS): a prospective, randomized, controlled pilot study of nutritional support in critically ill patients. Intensive Care Med 2011; 37:601– 609. Pichard C, Guttormsen AB, Berger MM, et al. Development and validation of a new indirect calorimetry device for energy expenditure measurement in ICU patients: The ICALIC international multicentric study. ESICM & ESPEN endorsed project 2014. Fiaccadori E, Regolisti G, Maggiore U. Specialized nutritional support interventions in critically ill patients on renal replacement therapy. Curr Opin Clin Nutr Metab Care 2013; 16:217–224. Van den Berghe G, Wouters P, Weekers F, et al. Intensive insulin therapy in critically ill patients. New Engl J Med 2001; 345:1359–1367.
www.co-clinicalnutrition.com
163
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Chronic critical illness nutritional requirements: more, less, or just different? Jeffrey I. Mechanick and Mette M. Berger
The miracle of ICU medical knowledge and technology has created the ‘chronic critical illness’ (CCI) syndrome and consequently, a host of novel and recycled derivative questions [1]. Regardless of the precise definition, CCI patients have survived their acute insult and interventions, and have generally been treated a few weeks in the ICU. Prior questions about early feeding and tight glycemic control targets are rendered moot, as the pathophysiology and metabolic imperatives of the new CCI state take priority. For the purpose of this brief commentary, let us view CCI as simply a state of prolonged critical illness and stipulate that the pathophysiology still needs unraveling. We have invited authors to address the various facets of this problem, but first, here are the questions, which can then be applied to CCI: (1) (2) (3) (4)
What physiopathology favors enteral nutrition? How should total energy delivery be adjusted? How should nitrogen requirements be adjusted? What is the role for nutritional pharmacology and adjuvant metabolic control? (5) What is a rational approach based on our knowledge, experience, and evidence base to integrate and apply the above answers? The nutrition support route question is addressed in the context of gut mucosal immunity by Fukatsu (pp. 164–170). This has been the source of much debate, and the author makes a crisp argument that enteral nutrition should be provided early and as consistently as possible to prevent impairment of gut mucosal function. The immune consequence of this function is important – a portion of the sensitized lymphocytes in the gutassociated lymphoid tissue that is stimulated by enteral feeds home to extraintestinal mucosal sites such as the respiratory tract, and thereby contribute to the mucosal defense. Corollaries to this conclusion are that combined enteral nutrition and parenteral nutrition and enteral nutrition surrogates, such as glutamine, may offer benefit of patients. CCI patients may derive particular benefit from this strategy. www.co-clinicalnutrition.com
The total energy question is addressed in the article by Guttormsen and Pichard (pp. 171–176), in which at the present time target amounts that cannot be determined through formulaic or modeled computations. Instead, the authors argue – and this approach has been validated in the recent studies [2,3] – that indirect calorimetry should be performed routinely and on a regular basis as individual energy requirements vary greatly. The major obstacle, however, is cost and acceptance of indirect calorimetry as a standard practice, especially with serial measurements during CCI when metabolic set points are dynamic in nature. This is the basis for two European societies (European Society of Clinical Nutrition and European Society of Intensive Care) supporting a 2014 multicenter research project promoting the development of a cheap, reliable indirect calorimeter for use in the ICU [4]. The nitrogen requirement question is addressed by Weijs (pp. 183–189). During the acute critical illness stage, guidelines recommend that early and sufficient protein feeding that is 1.3–1.5 g/kg/day be delivered and energy intake be informed by indirect calorimetry measurements. However, there are still very poor metrics for CCI nitrogen provision, and therefore an emphasis on safety is warranted. Hence, recommendations will continue to be impressionistic with CCI. This translates into a mandate for relevant nutrition support trials specifically in the CCI population, who are high-risk patients. The role of carnitine as an example of acute lifethreatening deficiencies is addressed by Bonafe´ et al. (pp. 200–209). Carnitine deficiency is probably under-recognized in CCI, and supplementation should be considered in high-risk patients. This is Division of Endocrinology, Diabetes and Bone Disease, Icahn School of Medicine at Mount Sinai, New York, New York, USA Correspondence to Mette M. Berger, MD, PhD, Service de Me´decine Intensive Adulte et Centre des Bruˆle´s, Lausanne University Hospital CHUV, Rue du Bugnon 46, CH – 1011 Lausanne, Switzerland. Tel: +41 21 31 42 095; fax: +41 21 31 43 045; e-mail: [email protected] Curr Opin Clin Nutr Metab Care 2014, 17:162–163 DOI:10.1097/MCO.0000000000000040 Volume 17 Number 2 March 2014
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
Chronic critical illness nutritional requirements Mechanick and Berger
a concept that requires further investigation particularly in patients who benefit from prolonged renal replacement therapy, which in addition to eliminating wishful ‘toxins’ causes manifold loss of water soluble micronutrients, such as trace elements and glutamine [5]. This precipitates metabolic and infectious complications. Unfortunately, the clinical evidence base is quite sparse, and any routine practice or stronger recommendation will need to await higher levels of scientific substantiation. The role of metabolic control is addressed by Okabayashi (pp. 190–199) with respect to intensive insulin therapy. As the initial Leuven protocol [6] triggered a resurgence of interest in ICU metabolic support, it has become clear that one cannot directly extrapolate highly controlled experimental findings to multisetting, complex, real-life scenarios. For years, we have emphasized that research studies need to address the specific clinical questions, and as advanced technology advances, the answers will also evolve. Closed-loop glycemic control systems must be evaluated in diverse complex settings to be pragmatic. Issues, such as glycemic variability, nature of nutrition support, and ICU logistics will all need to be incorporated. The role of a comprehensive approach is partially addressed by Kondrup (pp. 177–182) on nutritional risk scoring and clinical decisionmaking, especially for parenteral nutrition. As there are still no generally accepted and validated scoring systems to risk-stratify metabolic interventions for critical illness, the authors argue that, for now, decisions should be based on the severity of nutritional risk and the duration of underfeeding observed. Granted, this is rather simplified, but the message here, especially for CCI patients, is that dedicated studies focusing on approach (i.e., a specific decision algorithm) may be more important than a conventional single-intervention trial. Taken together, one can extrapolate many of these concepts to the CCI state, and fashion an approach wherein every ICU patient is risk stratified, enteral nutrition prioritized but parenteral nutrition used to ensure adequate total energy
and nitrogen, metabolic control parameters set using safe technology, and nutritional pharmacological agents applied judiciously. There are still no hard recommendations. However, we foresee an eventual personalized metabolic care plan for CCI patients that now can be based on an emerging body of information derived, not from purely academic research topics, but rather from practical research questions and Bayesian clinical trials. As coeditors, this will be our sixth and last issue of working together on Current Opinion’s Nutrition and the ICU. Although we have been vexed by incessant controversy, we marvel at the great progress made in studying real-life clinical ICU questions, especially for those with CCI. We are optimistic that where nutrition had been generally relegated to supportive and adjuvant care, it is now frequently recognized on rounds as a primary intervention, hashed out with greater zeal, scientific evidence, and action. So, for now, how would you describe CCI metabolic care compared with acute ICU care: ‘different... more or less’. Acknowledgements None. Conflicts of interest There are no conflicts of interest.
REFERENCES 1.
2.
3.
4.
5.
6.
1363-1950 ß 2014 Wolters Kluwer Health | Lippincott Williams & Wilkins
Schulman RC, Mechanick JI. Can nutrition support interfere with recovery from acute critical illness? In: Singer P, editor. Nutrition in intensive care medicine: Beyond physiology. Basel 2013. Heidegger CP, Berger MM, Graf S, et al. Optimisation of energy provision with supplemental parenteral nutrition in critically ill patients: a randomised controlled clinical trial. Lancet 2013; 381:385–393. Singer P, Anbar R, Cohen J, et al. The tight calorie control study (TICACOS): a prospective, randomized, controlled pilot study of nutritional support in critically ill patients. Intensive Care Med 2011; 37:601– 609. Pichard C, Guttormsen AB, Berger MM, et al. Development and validation of a new indirect calorimetry device for energy expenditure measurement in ICU patients: The ICALIC international multicentric study. ESICM & ESPEN endorsed project 2014. Fiaccadori E, Regolisti G, Maggiore U. Specialized nutritional support interventions in critically ill patients on renal replacement therapy. Curr Opin Clin Nutr Metab Care 2013; 16:217–224. Van den Berghe G, Wouters P, Weekers F, et al. Intensive insulin therapy in critically ill patients. New Engl J Med 2001; 345:1359–1367.
www.co-clinicalnutrition.com
163
Copyright © Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.
