Refeeding syndrome is a potentially fatal condition involving metabolic disturbances that occur during nutritional rehabilitation of malnourished patients. It is characterized by severe fluid and electrolyte shifts associated with metabolic abnormalities in patients with severe malnutrition during reintroduction of nutrition.

Key Points

• Life-threatening condition requiring careful monitoring
• Common electrolyte disturbances include hypophosphatemia, hypokalemia, and hypomagnesemia
• Occurs within first week of refeeding
• Prevention is crucial through risk assessment and careful refeeding
• Requires multidisciplinary management approach

Pathophysiological Mechanisms

Metabolic Changes During Starvation

• Hormonal adaptations
  • Decreased insulin secretion
  • Increased glucagon
  • Increased gluconeogenesis
• Fuel utilization shifts
  • Glycogen depletion
  • Protein catabolism
  • Fat metabolism
• Electrolyte depletion
  • Intracellular losses
  • Total body deficit

Changes During Refeeding

• Glucose/insulin effects
  • Increased glucose uptake
  • Enhanced glycogen synthesis
  • Increased protein synthesis
• Electrolyte shifts
  • Intracellular movement of phosphate
  • Potassium influx into cells
  • Magnesium depletion
• Fluid shifts
  • Sodium retention
  • Fluid overload
  • Edema formation

Risk Assessment

High-Risk Patient Groups

• Primary conditions
  • Anorexia nervosa
  • Chronic malnutrition
  • Chronic alcoholism
  • Oncology patients
  • Elderly with poor intake
• Clinical scenarios
  • Prolonged fasting (>7-10 days)
  • Post-operative patients
  • Uncontrolled diabetes mellitus
  • Chronic inflammatory conditions

Risk Stratification Criteria

• Major risk factors
  • BMI < 16 kg/m²
  • Weight loss > 15% in 3-6 months
  • Little/no nutrition for > 10 days
  • Low baseline electrolytes
• Minor risk factors
  • BMI < 18.5 kg/m²
  • Weight loss > 10% in 3-6 months
  • Little/no nutrition for > 5 days
  • History of alcohol/drug abuse

Clinical Manifestations

Cardiovascular

• Heart failure
• Arrhythmias
• Hypotension
• Tachycardia
• Cardiac arrest

Neurological

• Confusion
• Weakness
• Paresthesias
• Tremors
• Seizures
• Wernicke's encephalopathy

Hematological

• Hemolysis
• Thrombocytopenia
• Leukocyte dysfunction

Musculoskeletal

• Muscle weakness
• Rhabdomyolysis
• Respiratory muscle weakness

Treatment Protocol

Initial Assessment

• Laboratory evaluation
  • Electrolytes (including Mg, PO4)
  • Renal function
  • Liver function
  • Complete blood count
  • Blood glucose
• Clinical assessment
  • Vital signs
  • Fluid status
  • Nutritional status
  • Mental status

Nutritional Rehabilitation

• Initial feeding guidelines
  • Start at 5-10 kcal/kg/day (high risk)
  • 10-15 kcal/kg/day (lower risk)
  • Advance by 5-10 kcal/kg/day
• Macronutrient distribution
  • Carbohydrate: 40-50%
  • Protein: 15-20%
  • Fat: 30-40%

Electrolyte Replacement

• Phosphate
  • Oral: 30-90 mmol/day
  • IV: 0.16-0.64 mmol/kg
• Potassium
  • Oral: 20-40 mEq/day
  • IV: Based on deficit
• Magnesium
  • Oral: 240-720 mg/day
  • IV: 8-12 mEq/day

Monitoring & Prevention

Clinical Monitoring

• Daily monitoring
  • Vital signs q4-6h
  • Fluid balance
  • Weight
  • Mental status
• Laboratory monitoring
  • Electrolytes daily (first week)
  • Blood glucose q6h initially
  • Renal function daily
  • Liver function twice weekly

Preventive Measures

• Pre-feeding supplementation
  • Thiamine 200-300mg daily
  • Multivitamin
  • Trace elements
• Fluid management
  • Maintenance + deficit correction
  • Sodium restriction
  • Monitor for overload

Complications Prevention

• Cardiac monitoring
  • ECG monitoring
  • Daily cardiovascular exam
• Respiratory care
  • Oxygen saturation monitoring
  • Chest physiotherapy
• Nutritional advancement
  • Gradual caloric increase
  • Regular dietitian review
  • Adjustment based on tolerance