The importance of providing adequate nutrition as an adjunct to medical care was identified as early as the era of Hippocrates. Today, it is known that malnutrition is associated with increased infection rates, longer hospital length of stay, and increased hospital costs. Not surprisingly, malnutrition is also associated with increased mortality. For example, Correia and Waitzberg demonstrated that malnutrition is an independent predictor of mortality, morbidity and hospital expense after controlling for patient age and disease severity. Hence, it is imperative that the nutritional statuses of all patients be assessed throughout their hospitalizations in order to develop appropriate nutritional plans. This could potentially improve outcomes.
Unfortunately, the prevalence of malnutrition in the hospitalized patient was largely ignored until 1974 when Butterworth published his landmark paper entitled “The Skeleton in the Hospital Closet.” Shockingly 30 to 50% of inpatients are malnourished upon admission, and they tend not to improve nutritionally, and frequently worsen, while hospitalized.
This chapter is designed to assist the hospital physician in identifying those patients at increased risk of malnutrition, as well as determining the most appropriate nutritional prescription.
Every patient should have a nutrition assessment when admitted to the hospital. This is usually done by a dietitian or a nurse making use of a nutrition screening questionnaire. The assessment process includes a combination of anthropometric measurements, history and physical examination, and laboratory analyses. Utilization of any one parameter is unlikely to yield a reliably accurate determination of nutritional status all of the time. However, when all of these parameters are considered in conjunction, one can generally get a good idea of a patient's nutritional status.
Every patient should have a nutrition assessment when admitted to the hospital.
- IBW for a woman may be estimated as 100 pounds for the first 5 feet plus an additional 5 pounds for every inch over 5 feet. The IBW for a man is 106 pounds for the 5 five feet plus an additional 6 pounds for every inch over 5 feet.
- Underweight is a BMI less than 18 kg/m2, and overweight is a BMI greater than 25 kg/m2.
Pitfalls to relying on body weight as an indicator of nutritional status include
- fluid overload states, which falsely elevate weight in a malnourished patient;
- obesity, which may mask significant weight loss.
Anthropometric Measurements and Physical Assessment
Classically, nutritional status is assessed with anthropometric measurements. These area set of noninvasive, quantitative techniques for determining an individual's body fat composition by measuring specific dimensions of the body. This includes such parameters as height and weight, triceps skin-fold thickness, mid–upper arm circumference, and bodily circumference at the waist, hip, and chest. If such measurements fall below standard norms then one is considered malnourished. For example, healthcare professionals can compare a patient's weight to the “ideal” body weight (IBW) found ...