The prevalence of malnutrition has been reported as 20-50% among hospitalized patients and is secondary to chronic disease, acute illness or exacerbation, and aging populations. Screening for malnutrition in all hospitalized patients is mandated in the United States by the Joint Commission for Accreditation of Healthcare Organizations, and addressing concerns raised regarding nutritional status is integral for patient care and improved inpatient outcomes.A large number of nutritional scoring systems have been published that identify patients at risk for malnutrition. Most of these systems involve a measure of unintentional weight loss, severity of current illness, presence of chronic illness, and gastrointestinal tract function. Three of the most commonly used models are summarized in the table below.
FIGURE 1 In Scenario I, the patient underwent bariatric surgery, and her postoperative course of intentional weight loss over 12-20 months is typical of patients following this procedure. Although reduced intestinal surface area is present following Roux-en-Y gastric bypass, frank malabsorption leading to malnutrition is a rare adverse effect of this procedure, with a prevalence of approximately 1%. Individuals who suffer from malabsorption following gastric bypass typically have weight loss that continues beyond 20 months postoperatively. While hair loss can be a clinical sign of micronutrient deficiency, it is common following malabsorptive bariatric surgery and is nonspecific in this setting. Often hair loss for up to two years during the postoperative phase of a malabsorptive bariatric procedure cannot be attributed to a specific micronutrient deficiency.
Scenario II depicts an otherwise healthy individual with sudden onset of acute diverticulitis. Prior to this acute illness, he was well nourished. Though his dietary intake for the two days leading to hospitalization is poor and he is likely to be dehydrated, his internal nutrient stores are sufficient to compensate for this short duration of poor intake. Like many serum proteins, pre-albumin acts as an inverse acute phase reactant. Hepatic synthesis of pre-albumin is diminished during acute illness. Thus, the low serum pre-albumin levels in this scenario do not reflect low protein stores. Depending on his subsequent hospital course, he may develop malnutrition, which warrants continued evaluation. He does not presently meet criteria for malnutrition.
In Scenario III, the patient had several exacerbations of Crohn's disease, which can lead to malabsorption. In addition, individuals with gastrointestinal illness, such as Crohn's disease, may self-restrict their oral dietary intake in between flares due to persistence of abdominal pain, loose bowel movements, or fear of inducing another exacerbation. This patient lost over 10% of his body weight in the past 3 months. He also has a low body mass index and demonstrates varying tolerance of oral diet. These findings meet criteria for high nutritional risk or severe malnutrition by nearly any published classification method.
Scenario IV clearly represents an individual at high risk of malnutrition for several reasons: 1) She has a prolonged hospitalization; 2) She has acute critical illness; and 3) She has chronic illness – COPD – that can lead to malnutrition through reduced appetite, increased protein degradation, and increased autophagy secondary to chronic, low-grade systemic inflammation. She is considered at high risk for malnutrition by NUTRIC criteria, which is recommended for use in critically ill patients. Identifying patients such as the one in scenario IV emphasizes the need for aggressive provision of nutritional support for improved outcomes.