Defining malnutrition and nutrition risk has been a topic of many papers and discussions throughout the modern literature. Multiple definitions have been proposed, ranging from simple body weight measurements to a more all-encompassing concept looking at diseasespecific inflammatory states. Biochemical markers, elements of a history examination, physical examination findings, calculations, and technical tests have all been proposed to help further characterize and delineate those who might be at risk for malnutrition, translating to an increased risk of adverse outcomes after major surgery.
The purpose of this paper is to summarize some of the most utilized and most reliable ways to determine nutrition status within the scope of the North American Surgical Nutrition Summit (2012) and discuss how to incorporate these methods into the way that patients are screened preoperatively for elective surgery. Nutrition assessment is a topic that has garnered much discussion, research, rehashing, redefining, and confusion over the past several decades. From the provocative, emotion-evoking images of children in the third world, to the very obvious “starving in the midst of plenty” variety of malnutrition seen in the developed world, malnutrition means different things to different societies. What is malnutrition? Malnutrition, simply stated, can be defined as any alteration in the physiology, composition, or function of an organism attributable to a diet or disease state that adversely affects outcome. With regard to patient care and patient related outcomes, malnutrition has been demonstrated to increase morbidity and mortality, contribute to a patient’s decline in function and mobility, decrease quality of life, increase the frequency and length of hospital admissions, and lead to higher healthcare costs. There is a ubiquitous impact of a diet on patient outcome. In fact, in the developed world, malnutrition more often consists of “over nutrition” and not marasmus or kwashiorkor that is classically described. The practitioner must therefore be aware that, although a patient may look healthy enough to tolerate surgical stress, there may be an unrecognized nutrition risk. It is imperative that patients are evaluated for this risk preoperatively so as to achieve patient oriented outcome.
Perhaps the best tool to detect malnutrition is the highly trained clinician obtaining a sound history and physical examination so as to get a favourable patient outcome. However, there is a lack of nutrition training in undergraduate, graduate, and postgraduate medical education. This lack of education has led to a significant amount of confusion about not only the diagnosis of malnutrition but also what its effects in the clinical setting are. In addition, many clinicians express concern over the increase in patient volume and whether patients are adequately being assessed before elective surgery. Over the years, several different tools have been developed at major hospitals to help guide the assessment and screening for malnutrition. The trouble that often arises is which one to select. The Joint Commission on Accreditation of Healthcare Organizations (JCAHO) now mandates that all hospitals conduct nutrition screening within 24 hours of hospital admission. Some institutions have made nutrition screening a basic part of the patient intake forms on admission, and these screening tools have helped to identify those patients who would benefit from a formal assessment by a nutrition or metabolic support team. Unfortunately, these teams of experts are not readily available at some or even most institutions or small hospitals and are not frequently utilized in an outpatient or ambulatory setting to identify patients at risk for malnutrition before elective general surgery. A concise, easily implemented nutrition assessment tool would be of benefit to help these settings correctly gauge nutrition needs for their patients and implement them in an appropriate manner.