In a patient with ongoing malnutrition after several days of therapy, what emergency department interventions should be initiated to stabilize nutrition, correct electrolyte and vitamin deficiencies, and begin a safe re‑feeding regimen?

Emergency Department Management of Refeeding Syndrome in Malnutrition

In a malnourished patient who has not improved after several days of nutritional therapy, immediately administer thiamine 200-300 mg IV before any further feeding, aggressively correct electrolytes (phosphate 0.3-0.6 mmol/kg/day IV, potassium 2-4 mmol/kg/day, magnesium 0.2 mmol/kg/day IV), restrict calories to 5-10 kcal/kg/day, and monitor electrolytes 2-3 times daily for the first 72 hours to prevent life-threatening refeeding syndrome complications. 1

Immediate Actions in the Emergency Department

Pre-Feeding Vitamin Protocol (MUST be done first)

• Administer thiamine 200-300 mg IV immediately before any nutrition or glucose-containing fluids—this is absolutely mandatory to prevent Wernicke's encephalopathy, Korsakoff's syndrome, acute heart failure, and sudden death 1
• Never initiate feeding without prior thiamine administration, as carbohydrate loading in thiamine-deficient patients precipitates catastrophic neurological and cardiac complications 1
• Provide full B-complex vitamins IV simultaneously with thiamine and continue throughout the refeeding period 1
• Continue thiamine 200-300 mg IV daily for a minimum of 3 days, even if symptoms improve, as subclinical deficiency may persist 1

Aggressive Electrolyte Replacement Protocol

Start these replacements immediately and concurrently with thiamine:

• Phosphate: 0.3-0.6 mmol/kg/day IV (this is the most critical electrolyte in refeeding syndrome) 1
• Potassium: 2-4 mmol/kg/day (hypophosphatemia is typically accompanied by hypokalemia) 1
• Magnesium: 0.2 mmol/kg/day IV or 0.4 mmol/kg/day orally (hypomagnesemia commonly coexists) 1
• Calcium supplementation as needed based on laboratory values 1

Critical pitfall: Do not attempt to correct electrolytes alone before feeding—severely malnourished patients have massive intracellular deficits that cannot be corrected without simultaneous feeding to drive transmembrane transfer. Correcting electrolytes alone provides false security. 1

Nutritional Reintroduction Strategy

Caloric restriction is essential:

• Restrict energy to 5-10 kcal/kg/day for the first 48 hours in very high-risk patients (BMI <16, weight loss >15% in 3-6 months, no intake >10 days, or low baseline electrolytes) 1
• Increase gradually over 4-7 days until full requirements (25-30 kcal/kg/day) are reached 1
• Macronutrient distribution: 40-60% carbohydrate, 30-40% fat, 15-20% protein 1
• Protein intake: at least 1.2-2.0 g/kg ideal body weight per day 1

If symptoms develop during refeeding: temporarily decrease feeding to 5-10 kcal/kg/day rather than stopping completely to avoid rebound hypoglycemia 1

Intensive Monitoring Requirements

For the first 72 hours:

• Measure electrolytes (phosphate, potassium, magnesium, calcium) 2-3 times daily when refeeding hypophosphatemia is present 1
• Daily monitoring of electrolyte levels should continue for at least the first 72 hours, extending beyond 3 days if abnormalities persist 1
• Monitor volume status, fluid balance, heart rate and rhythm, and clinical status closely 1
• Strict glucose monitoring to avoid hyperglycemia 1
• Watch for clinical signs: edema, arrhythmias, confusion, respiratory failure 1

Route of Nutrition

Enteral feeding (oral or nasogastric) is preferred when gastrointestinal function is preserved, as it maintains gut barrier integrity, lowers infection rates, and is more cost-effective 1

Parenteral nutrition should only be used when:

1. Enteral feeding cannot meet energy needs, OR
2. Intestinal failure is present, OR
3. Severe upper-GI obstruction exists, OR
4. The patient cannot tolerate enteral route 1

Life-Threatening Complications to Watch For

Refeeding syndrome typically develops within the first 4 days after nutrition therapy is commenced and can be fatal: 1

Cardiovascular Manifestations

• Cardiac arrhythmias due to electrolyte imbalances (particularly hypophosphatemia, hypokalemia, hypomagnesemia) 1
• Congestive heart failure from fluid retention 1
• Hypotension and sudden cardiac death can occur in up to 20% of severe cases 1

Neurological Manifestations

• Delirium, confusion, seizures, and encephalopathy from rapid drops in plasma phosphate 1
• Wernicke's encephalopathy from thiamine deficiency (diplopia, confabulation, confusion, coma) 1
• Lethargy progressing to coma in severe cases 1

Respiratory Manifestations

• Respiratory failure requiring increased ventilatory support 1
• Difficulty weaning from mechanical ventilation 1

Other Complications

• Muscle weakness and rhabdomyolysis 1
• Hepatic dysfunction with excessive fat and glycogen storage 1

Special Considerations for High-Risk Patients

Very high-risk criteria requiring 5-10 kcal/kg/day start:

• BMI <16 kg/m² 1
• Unintentional weight loss >15% in 3-6 months 1
• No or minimal intake for >10 days 1
• Low baseline electrolytes before feeding 1
• History of chronic alcoholism 1
• Anorexia nervosa 1

In chronic alcoholism: 30-80% have thiamine deficiency, making thiamine administration absolutely mandatory before any glucose infusion 1

In older hospitalized patients: significant overlap between malnutrition risk and refeeding syndrome risk exists; avoid pharmacological sedation or physical restraints 1

Management of Persistent Symptoms

If nausea persists despite proper refeeding protocol:

• Ondansetron 4-8 mg orally or IV every 8 hours as needed after confirming adequate hydration 1
• Metoclopramide 10 mg three times daily if fullness and delayed gastric emptying predominate (maximum 3 days, monitor for QT prolongation and extrapyramidal symptoms) 1
• Avoid dimenhydrinate (worsens constipation and delayed gastric emptying) 1
• Smaller, more frequent meals rather than large bolus feeds 1

Critical Pitfalls to Avoid

1. Never initiate feeding without thiamine—carbohydrate loading precipitates acute Wernicke's encephalopathy and cardiac failure 1
2. Never stop thiamine prematurely—continue for the full minimum 3-day period 1
3. Never correct electrolytes alone pre-feeding—this gives false security without correcting massive intracellular deficits 1
4. Never stop feeding abruptly—taper gradually to avoid rebound hypoglycemia 1
5. Never overfeed—aggressive refeeding is more dangerous than cautious underfeeding in the acute phase 1