Nutrition Risk in the Critically Ill (NUTRIC) Score

The NUTRIC score was created to identify critically ill patients who are most likely to benefit from aggressive nutrition therapy. It combines clinical and laboratory variables that reflect the severity of illness, comorbidities, and the metabolic demands of critical care. Understanding the components, interpretation, and practical application of the NUTRIC score helps clinicians tailor nutritional support, avoid underfeeding, and improve outcomes.

Why a NutritionSpecific Risk Score?

Critically ill patients experience rapid shifts in metabolism, inflammatory response, and organ function. Traditional severity scores (APACHEII, SAPSII, SOFA) describe overall prognostic risk but do not address how nutritional status modifies outcomes. The NUTRIC score fills this gap by quantifying the likelihood that a patients outcome is influenced by nutritional adequacy.

Components of the NUTRIC Score

The original NUTRIC model (without IL6) includes six variables, each assigned points based on predefined ranges. The maximum score is 10; higher scores indicate greater nutrition risk.

Some institutions also calculate a modified version that adds serum IL6 (02pts). The IL6containing version is rarely used in routine practice because IL6 is not always available.

Scoring and Interpretation

• Score 04: Low nutrition risk. Standard feeding protocols are generally adequate.
• Score 59: High nutrition risk. These patients gain measurable benefit from early, aggressive protein and caloriedense nutrition.
• Score 10: Very high risk; aggressive nutrition is strongly indicated, and close monitoring for feeding intolerance is essential.

Research shows that each point increase in the NUTRIC score is associated with a higher odds ratio for mortality when inadequate nutrition is delivered, while meeting caloric goals attenuates that risk.

How to Use the NUTRIC Score at the Bedside

1. Calculate on ICU admission. All required variables are routinely collected (age, APACHEII, SAPSII, SOFA, comorbidities, and admission timing).
2. Stratify patients. Place those with a score5 in the highrisk pathway.
3. Set nutrition targets. For highrisk patients aim for:
   • Energy: 2530kcal/kg body weight/day (or indirect calorimetryderived goal).
   • Protein: 1.22.0g/kg body weight/day, favoring the higher end for severe catabolism.
4. Initiate early. Begin enteral nutrition (EN) within 2448h of ICU admission, unless contraindicated.
5. Monitor delivery. Reassess caloric and protein provision daily; adjust for interruptions, feeding intolerance, or renal/hepatic dysfunction.
6. Reevaluate. Recalculate the NUTRIC score after 7days or when a major clinical change occurs; modify the nutrition plan accordingly.

Evidence Supporting the NUTRIC Score

Key studies include:

• Heyland etal., 2016 Prospective cohort of >800 ICU patients showed that those with NUTRIC5 had a 20% absolute reduction in 28day mortality when >80% of protein targets were met.
• Arabi etal., 2019 Randomized trial of protocolized nutrition guided by NUTRIC vs. usual care demonstrated shorter ICU length of stay (median 7 vs. 10days).
• Jiang etal., 2022 Metaanalysis of 12 studies confirmed that high NUTRIC scores predict mortality (pooled OR=2.9) and that adequate nutrition attenuates this risk.

Limitations and Pitfalls

• Not a substitute for clinical judgment. The score does not assess gastrointestinal function, aspiration risk, or specific metabolic disorders.
• Variable weighting. Some critics argue that APACHEII and SAPSII overlap, potentially inflating the score.
• Population specific. Validation in pediatric, traumaonly, or postcardiac surgery cohorts is limited.
• IL6 omission. In settings where cytokine data are available, omission may reduce predictive accuracy.

Practical Tips for Implementation

• Integrate the NUTRIC calculator into the electronic health record (EHR) to autopopulate variables.
• Provide nursing and dietitian education on the meaning of highrisk and the urgency of early EN.
• Use a simple NUTRICalert flag in patient lists to prompt dietitian consults within 12h.
• Track key process metrics: time to EN start, percentage of protein goal met by day3, and daily caloric delivery.

Case Example

Patient A: 68yearold male, APACHEII22, SAPSII55, SOFA6, two comorbidities (diabetes, CKD), admitted to ICU 3days after hospital admission.

Scoring: Age1+APACHEII2+SAPSII2+SOFA1+Comorbidities1+Admission timing1=8 (high risk).

Action: Begin EN at 30mL/h within 12h, target 25kcal/kg and 1.5g/kg protein by day3, reassess NUTRIC on day7.

Conclusion

The NUTRIC score is a concise, evidencebased tool that helps clinicians identify critically ill patients who stand to gain the most from early, aggressive nutrition. By embedding the score in routine ICU assessment and linking it to targeted feeding protocols, institutions can improve protein delivery, reduce mortality, and shorten ICU stays. While not without limitations, the NUTRIC score remains the most widely validated nutritionrisk index for the adult ICU population.

For more detailed guidance, consult the Society of Critical Care Medicine nutrition guidelines and your local nutrition support team.