Malnutrition Assessment and Management

Initial Evaluation

The American College of Physicians recommends obtaining a core laboratory panel including complete blood count, comprehensive metabolic panel with electrolytes and liver enzymes, serum albumin with inflammatory markers, prealbumin, and iron studies for patients suspected of malnutrition 1
The initial core laboratory panel should include complete blood count to evaluate hemoglobin and total lymphocyte count, which reflect protein status and immune function 1, 2
Comprehensive metabolic panel including electrolytes, liver enzymes, and renal function should be measured to assess overall health 1, 3
Serum albumin should be measured alongside C-reactive protein or other inflammatory markers to distinguish inflammation from true nutritional deficiency 1, 4
Prealbumin or retinol-binding protein should be measured as they have shorter half-lives and are superior for detecting recent nutritional changes 1, 2, 4

The initial micronutrient panel should include vitamin B12 and folate to identify deficiencies causing megaloblastic anemia and neurological complications 1
Vitamin D levels should be measured, with sufficiency defined as ≥75 nmol/L 1
Iron studies including serum ferritin and transferrin saturation should be evaluated to assess iron status and anemia 1

Validated risk scores combining multiple parameters should be used rather than relying on isolated laboratory values, as the predictive value of each individual parameter alone is insufficient 1, 4
Available tools include prognostic inflammatory and nutritional index, nutritional risk index, prognostic nutritional risk, and aid for decision for nutritional support score 1, 4

The frequency of laboratory monitoring depends on malnutrition severity, with daily monitoring of electrolytes and glucose during initial stabilization for severe malnutrition or critically ill patients 1, 3
Stable patients with chronic malnutrition should be monitored every 3 months, measuring body weight and serum albumin at minimum until stabilized 1

When initiating feeding in malnourished patients, electrolytes should be checked at least daily to prevent refeeding syndrome 1
Patients with BMI <16 kg/m², unintentional weight loss >15% in 3-6 months, little or no intake for >10 days, or low potassium, phosphate, or magnesium before feeding are at high risk for refeeding syndrome 5
Thiamine should be administered prior to starting glucose infusion to reduce risk of Wernicke's encephalopathy 3

For liver disease patients, liver-specific nutritional screening tools like the Royal Free Hospital-nutritional prioritizing tool (RFH-NPT) should be used 1
CT scan at L3 vertebra should be used to measure skeletal muscle index for sarcopenia assessment 6, 7
For chronic kidney disease patients, body weight and serum albumin should be monitored every 3 months in patients with GFR <30 ml/min per 1.73 m² 1

Albumin should not be relied upon solely as a malnutrition marker without inflammatory markers 1
Weight changes should not be interpreted without assessing fluid status, as edema and ascites make weight measurements unreliable 1
Transferrin alone should not be used as it shows poor correlation with nutritional status in many populations 1
Nutritional intervention should not be delayed to obtain extensive micronutrient panels in acutely ill patients; basic metabolic assessment is sufficient to start safely 3