Nutritional Risk Score (NRS-2002)

NRS-2002 is specifically validated for hospitalised patients and includes a disease severity component, making it suitable for patients with severe acute illness (ICU, post-operative). MUST (Malnutrition Universal Screening Tool) is validated across community, outpatient, and hospital settings and is simpler (3 steps: BMI, unintentional weight loss, acute disease effect). MUST is recommended for community and primary care screening; NRS-2002 is preferred for hospital inpatients. Both identify patients who require nutritional assessment and intervention.

Nutritional support is stepped according to clinical need: first, oral nutritional supplements (ONS) — high-calorie and high-protein drinks or fortified foods; second, enteral tube feeding (nasogastric, nasojejunal, or PEG) if oral route is inadequate or unsafe (dysphagia, post-oesophageal surgery); third, parenteral nutrition (PN) if the gastrointestinal tract is non-functional (short bowel syndrome, intestinal failure, post-major GI surgery). Energy target: 25–35 kcal/kg/day; protein target: 1.2–2.0 g/kg/day depending on clinical condition.

Older patients have reduced physiological reserve, including reduced muscle mass (sarcopenia), impaired immune function, lower bone density, and reduced capacity to recover from acute illness. Even if their nutritional status and disease severity scores are equivalent to younger patients, older patients have worse outcomes from malnutrition and are more likely to benefit from nutritional support. The 1-point age adjustment reflects this increased vulnerability.

Hospital malnutrition — affecting 20–40% of hospitalised patients — is associated with significantly worse outcomes: increased post-operative complications (wound infection, anastomotic leak, pneumonia), prolonged hospital stay (average 5.4 additional days per malnourished patient), higher readmission rates, increased mortality, greater pressure ulcer incidence, and delayed functional recovery. ESPEN estimates that hospital malnutrition costs the EU healthcare system over €100 billion annually.

ESPEN recommends rescreening with NRS-2002 every week during hospitalisation in patients who initially score <3, as clinical deterioration can increase nutritional risk over time. Patients who score ≥3 should have a full nutritional assessment by a dietitian and a personalised nutritional care plan, with progress reviewed at least weekly. In rapidly changing clinical situations (e.g., critical care), daily review of nutritional adequacy is appropriate.

Refeeding syndrome is a potentially life-threatening complication of initiating nutritional support in severely malnourished patients. It is characterised by dangerous falls in serum phosphate, potassium, and magnesium as these electrolytes shift into cells during the anabolic response to refeeding, causing cardiac arrhythmias, respiratory failure, heart failure, and neurological complications. Prevention: identify high-risk patients (BMI <16, negligible food intake for >10 days, significant prior weight loss), check and correct electrolytes before feeding, start at 10 kcal/kg/day and increase slowly over 7 days, supplement thiamine before and during refeeding (100 mg three times daily).

ESPEN recommends protein intake of 1.2–2.0 g/kg/day for malnourished hospitalised patients, compared to 0.8 g/kg/day for healthy adults. In critically ill patients, ESPEN recommends 1.3 g/kg/day (higher in burns, trauma, ICU). Higher protein intakes (up to 2.5 g/kg/day) may be appropriate in some high-catabolism states. Energy delivery (non-protein calories) should be 25–30 kcal/kg/day in most hospitalised patients, with caloric targets adapted for critically ill patients in the first week of ICU admission.

NRS-2002 was specifically developed and validated for hospitalised adult patients. It is not validated for outpatient or community use. MUST (Malnutrition Universal Screening Tool) is validated for community, outpatient, and hospital settings and is recommended by NICE and BAPEN for primary care and nursing home screening. For oncology outpatients, the PG-SGA (Patient-Generated Subjective Global Assessment) is widely used. Always use the tool validated for the specific care setting.