517006
research-article2013
NCPXXX10.1177/0884533613517006Nutrition in Clinical PracticeEvans et al
Invited Review
Nutrition Optimization Prior to Surgery David C. Evans, MD1; Robert G. Martindale, MD, PhD2; Laszlo N. Kiraly, MD2; and Christopher M. Jones, MD3
Nutrition in Clinical Practice Volume 29 Number 1 February 2014 10–21 © 2013 American Society for Parenteral and Enteral Nutrition DOI: 10.1177/0884533613517006 ncp.sagepub.com hosted at online.sagepub.com
Abstract Optimization of metabolic state prior to major surgery leads to improved surgical outcomes. Nutrition screening protocols should be implemented in the preoperative evaluation, possibly as part of a bundle. Strategies to minimize hyperglycemia and insulin resistance by aggressive preoperative nutrition and carbohydrate loading may promote maintenance of a perioperative anabolic state, improving healing, reducing complications, and shortening the time to recovery of bowel function and hospital discharge. Short courses of preoperative immune-modulating formulas, using combinations of arginine, ω-3 fatty acids, and other nutrients, have been associated with improved surgical outcomes. These immune-modulating nutrients are key elements of metabolic pathways that promote attenuation of the metabolic response to stress and improve both wound healing and immune function. Patients with severe malnutrition and gastrointestinal dysfunction may benefit from preoperative parenteral nutrition. Continuation of feeding through the intraoperative period for severely stressed hypermetabolic patients undergoing nongastrointestinal surgery is another strategy to optimize metabolic state and reduce prolonged nutrition deficits. In this paper, we review the importance of preoperative nutrition and strategies for effective preoperative nutrition optimization. (Nutr Clin Pract. 2014;29:10-21)
Keywords preoperative period; preoperative care; surgery; nutritional support; nutrition assessment; enteral nutrition; parenteral nutrition
Importance of Preoperative Nutrition on Surgical Outcomes Preoperative evaluation prior to elective surgery is routinely performed with the goal of optimizing patient outcomes. The purpose of a preoperative evaluation is not to “clear” patients for elective surgery but rather to evaluate them and, if necessary, implement measures to prepare higher risk patients for surgery. A thorough evaluation usually includes a history and physical examination, focusing on risk factors for cardiac, pulmonary, and infectious complications, along with a determination of a patient’s functional capacity. The nutrition state of the patient, however, is often omitted from this preoperative assessment. Malnourishment may be present for a variety of reasons in patients undergoing elective surgery, including metabolic perturbations from inflammatory or neoplastic disease, altered nutrient utilization secondary to the metabolic state, poor access to adequate nutrition, or alimentary track dysfunction. Ideally, these nutritionally at-risk patients should be identified during a preoperative evaluation, and nutrition goal-directed therapy should be implemented prior to surgery. Nutrition goals, at the most basic level, should be to provide caloric and nitrogenous support for wound healing and to avoid excessive loss of lean body mass. As our understanding of nutrition therapy has progressed, these goals have broadened to include modulating inflammation and the immune response, optimizing glucose control, attenuating the hypermetabolic response to surgery, and providing micro- and macronutrients to optimize healing and recovery. Hypermetabolism can last for
weeks or months after major surgery or trauma, entailing significant protein losses of lean body mass, primarily from muscle.1 Numerous studies have shown a clear association between malnutrition and poor surgical outcomes.2–7 These outcomes include not only increased overall mortality but also morbidity, such as increased hospital stay, increased intensive care unit (ICU) admissions, delayed wound healing, central line-associated bloodstream infections, surgical site infections, and other infectious complications. A well-performed study in Geneva, Switzerland, examined lean body mass at hospital admission and found lean body mass depletion to be an independent risk factor for increased length of hospital stay.8 From 1The Ohio State University, Department of Surgery, Columbus, Ohio; 2Oregon Health & Science University, Department of Surgery, Portland, Oregon; and 3University of Louisville, Department of Surgery, Louisville, Kentucky. Financial disclosure: None declared. This article originally appeared online on December 17, 2013. Corresponding Author: Christopher M. Jones, MD, University of Louisville, Hiram C. Polk Jr MD Department of Surgery, Ambulatory Care Building, 2nd Floor, Louisville, KY 40292, USA. Email: [email protected]
Download a QR code reader on your smartphone, scan this image, and listen to the podcast for this article instantly. Or listen to this and other NCP podcasts at http://ncp.sagepub.com/site/misc/ Index/Podcasts.xhtml.
Evans et al Meta-analysis of several well-designed trials has shown benefit from preoperative enteral nutrition supplementation.9 A randomized prospective trial of >1000 patients was assessed using a simple screening tool: Nutrition Risk Screening (NRS-2002).10 Patients deemed to be at high nutrition risk were randomized to nutrition intervention vs standard of care. The standard of care was to proceed with surgical intervention without the preoperative nutrition intervention, despite the screening. Preoperative nutrition intervention in the high-risk group was reported to have decreased major morbidity by 50%.11 According to a systematic review, other prospective randomized clinical trials have reported a decrease in infectious complications as well as decreased length of hospital and ICU stay, although no mortality benefit has been shown.12
Preoperative Nutrition Assessment An important factor affecting outcome and recovery from surgical stress is preoperative nutrition status and the patient’s metabolic response to the surgical insult. The Joint Commission requires nutrition screening to be initiated within 24 hours of admission and a full assessment to be performed for at-risk patients.13 The question raised, however, is what constitutes “atrisk” or “malnourished.” The traditional concept of malnutrition brings to mind low body mass index (BMI) and decreased muscle mass (sarcopenia). Several categories, however, have been proposed that take into account both chronic and acute states of inflammation associated with disease and injury, and these must be considered when assessing one’s nutrition status. When assessing preoperative nutrition status, practitioners need tools that take into account previous operations and disease processes that may affect nutrition status.14 Obesity, for example, is categorized as malnutrition of chronic disease with inflammation. It is not uncommon to see sarcopenia in this population group. Sarcopenia is usually associated with the geriatric population, where decreased functional and hormonal imbalances are present, but it is also seen in the obese, who are subject to the same imbalances. Although obesity is most commonly associated with macronutrient excess, it is reported that at least 15%−20% of obese patients may be nutritionally deficient in at least one micronutrient.15,16 Sarcopenic obesity is common in the bariatric population; this results in a dramatic increase in perioperative morbidity, including an increased need for postoperative ventilator support, increased duration of ICU stay, and worsening infectious complications. A variety of nutrition screening and assessment tools are available. They consist of historical and physical examination data, such as weight loss history, fat store loss, muscle wasting, and BMI, as well as laboratory data such as lymphocyte count and serum levels of albumin, prealbumin, and cholesterol.17 Visceral proteins are important as predictors of risk but are not indicative of actual measures of malnutrition
11 per se. The large prospective Preoperative Risk Assessment Study conducted by the U.S. Department of Veterans Affairs reported that the single most valuable predictor of poor outcome was a serum albumin level
research-article2013
NCPXXX10.1177/0884533613517006Nutrition in Clinical PracticeEvans et al
Invited Review
Nutrition Optimization Prior to Surgery David C. Evans, MD1; Robert G. Martindale, MD, PhD2; Laszlo N. Kiraly, MD2; and Christopher M. Jones, MD3
Nutrition in Clinical Practice Volume 29 Number 1 February 2014 10–21 © 2013 American Society for Parenteral and Enteral Nutrition DOI: 10.1177/0884533613517006 ncp.sagepub.com hosted at online.sagepub.com
Abstract Optimization of metabolic state prior to major surgery leads to improved surgical outcomes. Nutrition screening protocols should be implemented in the preoperative evaluation, possibly as part of a bundle. Strategies to minimize hyperglycemia and insulin resistance by aggressive preoperative nutrition and carbohydrate loading may promote maintenance of a perioperative anabolic state, improving healing, reducing complications, and shortening the time to recovery of bowel function and hospital discharge. Short courses of preoperative immune-modulating formulas, using combinations of arginine, ω-3 fatty acids, and other nutrients, have been associated with improved surgical outcomes. These immune-modulating nutrients are key elements of metabolic pathways that promote attenuation of the metabolic response to stress and improve both wound healing and immune function. Patients with severe malnutrition and gastrointestinal dysfunction may benefit from preoperative parenteral nutrition. Continuation of feeding through the intraoperative period for severely stressed hypermetabolic patients undergoing nongastrointestinal surgery is another strategy to optimize metabolic state and reduce prolonged nutrition deficits. In this paper, we review the importance of preoperative nutrition and strategies for effective preoperative nutrition optimization. (Nutr Clin Pract. 2014;29:10-21)
Keywords preoperative period; preoperative care; surgery; nutritional support; nutrition assessment; enteral nutrition; parenteral nutrition
Importance of Preoperative Nutrition on Surgical Outcomes Preoperative evaluation prior to elective surgery is routinely performed with the goal of optimizing patient outcomes. The purpose of a preoperative evaluation is not to “clear” patients for elective surgery but rather to evaluate them and, if necessary, implement measures to prepare higher risk patients for surgery. A thorough evaluation usually includes a history and physical examination, focusing on risk factors for cardiac, pulmonary, and infectious complications, along with a determination of a patient’s functional capacity. The nutrition state of the patient, however, is often omitted from this preoperative assessment. Malnourishment may be present for a variety of reasons in patients undergoing elective surgery, including metabolic perturbations from inflammatory or neoplastic disease, altered nutrient utilization secondary to the metabolic state, poor access to adequate nutrition, or alimentary track dysfunction. Ideally, these nutritionally at-risk patients should be identified during a preoperative evaluation, and nutrition goal-directed therapy should be implemented prior to surgery. Nutrition goals, at the most basic level, should be to provide caloric and nitrogenous support for wound healing and to avoid excessive loss of lean body mass. As our understanding of nutrition therapy has progressed, these goals have broadened to include modulating inflammation and the immune response, optimizing glucose control, attenuating the hypermetabolic response to surgery, and providing micro- and macronutrients to optimize healing and recovery. Hypermetabolism can last for
weeks or months after major surgery or trauma, entailing significant protein losses of lean body mass, primarily from muscle.1 Numerous studies have shown a clear association between malnutrition and poor surgical outcomes.2–7 These outcomes include not only increased overall mortality but also morbidity, such as increased hospital stay, increased intensive care unit (ICU) admissions, delayed wound healing, central line-associated bloodstream infections, surgical site infections, and other infectious complications. A well-performed study in Geneva, Switzerland, examined lean body mass at hospital admission and found lean body mass depletion to be an independent risk factor for increased length of hospital stay.8 From 1The Ohio State University, Department of Surgery, Columbus, Ohio; 2Oregon Health & Science University, Department of Surgery, Portland, Oregon; and 3University of Louisville, Department of Surgery, Louisville, Kentucky. Financial disclosure: None declared. This article originally appeared online on December 17, 2013. Corresponding Author: Christopher M. Jones, MD, University of Louisville, Hiram C. Polk Jr MD Department of Surgery, Ambulatory Care Building, 2nd Floor, Louisville, KY 40292, USA. Email: [email protected]
Download a QR code reader on your smartphone, scan this image, and listen to the podcast for this article instantly. Or listen to this and other NCP podcasts at http://ncp.sagepub.com/site/misc/ Index/Podcasts.xhtml.
Evans et al Meta-analysis of several well-designed trials has shown benefit from preoperative enteral nutrition supplementation.9 A randomized prospective trial of >1000 patients was assessed using a simple screening tool: Nutrition Risk Screening (NRS-2002).10 Patients deemed to be at high nutrition risk were randomized to nutrition intervention vs standard of care. The standard of care was to proceed with surgical intervention without the preoperative nutrition intervention, despite the screening. Preoperative nutrition intervention in the high-risk group was reported to have decreased major morbidity by 50%.11 According to a systematic review, other prospective randomized clinical trials have reported a decrease in infectious complications as well as decreased length of hospital and ICU stay, although no mortality benefit has been shown.12
Preoperative Nutrition Assessment An important factor affecting outcome and recovery from surgical stress is preoperative nutrition status and the patient’s metabolic response to the surgical insult. The Joint Commission requires nutrition screening to be initiated within 24 hours of admission and a full assessment to be performed for at-risk patients.13 The question raised, however, is what constitutes “atrisk” or “malnourished.” The traditional concept of malnutrition brings to mind low body mass index (BMI) and decreased muscle mass (sarcopenia). Several categories, however, have been proposed that take into account both chronic and acute states of inflammation associated with disease and injury, and these must be considered when assessing one’s nutrition status. When assessing preoperative nutrition status, practitioners need tools that take into account previous operations and disease processes that may affect nutrition status.14 Obesity, for example, is categorized as malnutrition of chronic disease with inflammation. It is not uncommon to see sarcopenia in this population group. Sarcopenia is usually associated with the geriatric population, where decreased functional and hormonal imbalances are present, but it is also seen in the obese, who are subject to the same imbalances. Although obesity is most commonly associated with macronutrient excess, it is reported that at least 15%−20% of obese patients may be nutritionally deficient in at least one micronutrient.15,16 Sarcopenic obesity is common in the bariatric population; this results in a dramatic increase in perioperative morbidity, including an increased need for postoperative ventilator support, increased duration of ICU stay, and worsening infectious complications. A variety of nutrition screening and assessment tools are available. They consist of historical and physical examination data, such as weight loss history, fat store loss, muscle wasting, and BMI, as well as laboratory data such as lymphocyte count and serum levels of albumin, prealbumin, and cholesterol.17 Visceral proteins are important as predictors of risk but are not indicative of actual measures of malnutrition
11 per se. The large prospective Preoperative Risk Assessment Study conducted by the U.S. Department of Veterans Affairs reported that the single most valuable predictor of poor outcome was a serum albumin level
