Refeeding Syndrome

Potentially life-threatening constellation of electrolyte abnormalities that occurs after nutritional intake is resumed following a period of starvation, characterised by:

Epidemiology and Risk Factors

Risk factors:

  • Malnutrition
    • Eating disorders
    • Alcohol and drug use
    • Vomiting
    • Dysphagia
    • Chemotherapy
    • Post-operative
    • Elderly
  • Low BMI (<18)
  • Duration of starvation (>5 days)
  • Recent unintentional weight loss

Pathophysiology

Starvation leads to:

  • Catabolic state
  • Total body phosphate depletion
    Secondary to muscle catabolism.

Provision of a glucose load with resumption of feeding causes a ↑↑ in insulin release, and:

  • Transition to catabolic state
  • Massive cellular uptake of PO43-, K+, and Mg2+
  • Concomitant fall in serum electrolyte concentrations
    • PO43- ↓ as it is required to hold glucose within cells
      Skeletal muscle is the dominant consumer.
    • K+ falls directly due to insulin release

Aetiology

Clinical Features

Clinical Features of Refeeding Syndrome, by Electrolyte Derangement
System Hypophosphataemia Hypokalaemia Hypomagnesaemia
Respiratory
  • Hypoventilation
    Weakness.
CVS
  • Systolic heart failure
  • Arrhythmia
  • Arrhythmias
  • Arrhythmias
Neurological
  • Metabolic encephalopathy
  • Seizures
  • Seizures
  • Confusion
  • Ataxia
  • Paraesthesias
Renal
  • ATN
  • Alkalosis
  • ↓ Potassium response
  • Hypocalcaemia
GIT
  • Dysphagia
  • Ileus
  • Ileus
Haematological
  • Haemolysis
    ↑ RBC rigidity.
Integumentary
  • Weakness
  • Rhabdomyolysis
  • Weakness
  • Tetany

Other features may include:

  • Hyponatraemia
    Occurs with a carbohydrate-rich diet as the carbohydrate is metabolised into water and CO2.
  • Hypernatraemia
    Occurs with protein-heavy diets as the protein metabolism produces urea; and the ↑ in obligatory solute load ↑ renal water elimination.

Assessment

History:

Exam:

Investigations

Bedside:

Laboratory:

Imaging:

Other:

Diagnostic Approach and DDx

Management

  • Identify high-risk patients, and institute feeds slowly
  • Aggressively replace electrolytes

Specific therapy:

  • Pharmacological
    • Aggressive electrolyte replacement
  • Procedural
  • Physical

Supportive care:

  • C
    • Arterial line
      For sampling.
    • CVC
      For TPN.
    • Cautious volume administration
  • D
    • Insulin for BSL control, if required
  • F
    • IDC
      For monitoring of urine output.

Preventative:

  • Identify at-risk patients
  • Slow introduction of feeds
    • 50% of predicted requirements, ↑ by 10% every 24 hours
  • Replace micronutrients
    • Thiamine 200-300mg PO daily
    • Multivitamins
      Single multivitamin daily.
    • Trace elements
      • Zinc
      • Iron
      • Selenium

Marginal and Ineffective Therapies

Anaesthetic Considerations

Complications

Prognosis

Key Studies

References

  1. Crook MA. Refeeding syndrome: Problems with definition and management. Nutrition. 2014;30(11-12):1448-1455. doi:10.1016/j.nut.2014.03.026
  2. Sharma S, Hashmi MF, Castro D. Hypophosphatemia. In: StatPearls. StatPearls Publishing; 2023. Accessed July 9, 2023. http://www.ncbi.nlm.nih.gov/books/NBK493172/