Nutrition Screening, Assessment, and Early Enteral Nutrition in the PICU

Screening and Initial Assessment

• All children admitted to the PICU should have their nutritional status assessed within 24‑48 hours of admission using anthropometric measurements expressed as z‑scores; those identified at risk require a comprehensive nutritional assessment and early enteral nutrition (EN) should be started within 24 hours unless contraindicated. [@1]
• Weight and height/length (or weight‑for‑length for children < 2 years) must be measured and documented with BMI‑for‑age z‑scores (or weight‑for‑length z‑scores) on admission. [@1]
• Head circumference should be recorded in all children younger than 36 months. [@1]
• Mid‑upper‑arm circumference (MUAC) is recommended as part of the initial anthropometric panel. [@1]
• All anthropometric data should be expressed as z‑scores rather than percentiles for greater precision. [@1]
• No pediatric nutrition screening tool has been validated specifically for the PICU population or for outcomes such as morbidity, mortality, or quality of life. [@3]

Comprehensive Nutritional Assessment for At‑Risk Patients

• Patients flagged as at‑risk must undergo a full nutritional assessment within 48 hours, including medical and dietary history (focus on recent weight‑loss percentage), duration/severity of reduced intake, physical examination for muscle wasting, subcutaneous fat loss, edema, and evaluation of underlying disease severity. [@1]

Early Enteral Nutrition Initiation

• Early EN should be initiated within the first 24 hours of PICU admission for all eligible children. [@1]
• Initiating EN within 24‑48 hours is associated with shorter duration of mechanical ventilation, lower rates of nosocomial infection, and reduced mortality. (Grade C evidence) [@1]
• EN is the preferred route of nutrient delivery over parenteral nutrition (PN). [@1]

Feeding Protocols and Advancement

• Enteral feeds should be advanced stepwise using a standardized feeding protocol or guideline until prescribed caloric/protein goals are met. [@1]
• Feeding protocols improve the time to EN initiation and increase overall nutrient intake (Grade C evidence). [@1]
• In high‑risk populations, feeding protocols reduce adverse events such as feeding intolerance (Grade D evidence). [@1]
• Achieving at least two‑thirds of the prescribed nutrient goal during the first week is linked to better clinical outcomes. [@6]

Special Populations – Hemodynamic Instability

• Once hemodynamically stabilized, early EN is recommended for:
  
  • Children receiving vasoactive medications (Grade D evidence)
  • Children supported with extracorporeal life support (ECLS/ECMO) (Grade D evidence)
  • Children post‑cardiac surgery (Grade C evidence)
  • Term neonates on pharmacologic hemodynamic support (GCP recommendation)
    *All recommendations are supported by the Intensive Care Medicine guideline. [@1]

Parenteral Nutrition Timing

• Withholding PN for up to one week can be considered in critically ill term neonates and children, regardless of current nutritional status, provided micronutrients are supplied (Grade B evidence). [@1]
• This approach reflects a shift from older recommendations and is based on recent high‑quality evidence. [@5]
• Micronutrient supplementation must continue throughout the PN‑withholding period. [@1]

Route of Enteral Feeding

• Gastric feeding is as safe as post‑pyloric feeding for the majority of critically ill children (Grade C evidence). [@2]
• Post‑pyloric feeding should be reserved for children at high risk of aspiration or who require frequent fasting for procedures (GCP recommendation). [@2]
• Routine measurement of gastric residual volumes is not recommended (Grade D evidence). [@2]

Ongoing Monitoring

• Nutritional status should be re‑evaluated at least weekly throughout the PICU stay. [@1]
• Hospitalized children are at risk of rapid nutritional deterioration, which adversely impacts clinical outcomes. [@1]
• Anthropometric measurements must be repeated regularly during admission. [@1]
• Muscle wasting occurs quickly in critically ill children and requires continuous assessment. (Evidence from Intensive Care Medicine) [@9]

Critical Pitfalls to Avoid

• Do not rely solely on BMI or a single anthropometric measurement to identify at‑risk children. [@3]
• Adult screening tools (e.g., NRS‑2002, MUST, MNA) must not be used in pediatric patients. [@3]
• Positive screening results must be followed by a comprehensive nutritional assessment; screening alone is insufficient. [@3]
• Do not postpone EN initiation because of hemodynamic instability when the patient is otherwise stable; EN should commence once vasoactive support or ECLS is stabilized. [@1]
• Routine use of prokinetic agents is not recommended due to insufficient evidence of benefit for gastric emptying or feed tolerance. (GCP recommendation) [@2]

Clinical Impact of Malnutrition in the PICU

• Malnutrition is present in approximately 15‑25 % of children at PICU admission. (Intensive Care Medicine data) [@9]
• Malnourished children experience:
  
  • Longer periods of mechanical ventilation
  • Higher incidence of hospital‑acquired infections
  • Prolonged PICU and overall hospital length of stay
  • Increased mortality risk
• Up to 40 % of hospitalized children with chronic conditions are affected by malnutrition. (Praxis Medical Insights) [@3]