refeeding syndrome

The patient whose potassium and phosphate levels drop with the reintroduction of nutrition has refeeding syndrome. They need electrolyte replacement. It is not rocket science.

Headline
Etiology first week of refeeding - electrolyte shifts.
Epidemiology
Clinical presentation pulmonary oedema, heart failure, arrhythmia, encephalopathy
↓ phosphate, ↓ K, ↓ Mg
HAEM: poor platelet function
MSK: rhabdo??? tetany, muscle weakness (leading to prolonged vent weans etc.)
Pathogenesis Insulin release, thiamine depletion.
Total body phosphate stores depleted - lost when muscle broken down, then in urine → depleted further with glycolysis when carbohydrates are introduced
Insulin release = ↓ K
Thiamine is a cofactor for carbohydrate metabolism
Diagnostic investigations
Management Replace what's lost
Careful slow refeeding - dieticians will guide
...it really isn't rocket science

risk assessment

HIGH RISK: Patients classified as high risk have two or more of the following:

  • BMI less than 18.5 kg/m2 
  • Frail elderly patients assessed by the dietitian as being at nutritional risk
  • Unintentional weight loss greater than 10% within the last 3 – 6 months
  • Little or no nutritional intake for more than 5 days
  • Morbidly obese patients with rapid weight loss (e.g. after gastric ballooning or banding)
  • Oncology therapy (i.e chemo or radiation treatments) especially head/neck/gastrointestinal patients
  • Major stressors without food for > 3 days
  • Post-operative or fasted for long periods of time

Extremely high risk:

  • BMI less than 16 kg/m2
  • Anorexia nervosa
  • Unintentional weight loss greater than 15% within the last 3 – 6 months (includes obese patients)
  • Little or no nutritional intake for more than 10 days
  • Low levels of potassium, phosphate or magnesium prior to feeding
    • However normal serum levels do not mean that the patient is not at risk. Their total body stores may be significantly depleted
  • Chronic malnutrition:
    • Alcoholism
    • Marasmus
    • Kwashiorkor
    • Hunger strikers
    • Malabsorption states