Refeeding Syndrome: Epidemiology, Pathophysiology

Refeeding Syndrome is seen in patients with severe malnutrition, starvation, and alcoholism. It is also very commonly seen in obese patients who have done a very fast(rapid) weight loss. It more commonly occurs in total parenteral nutrition than in enteral Nutrition(EN).

Patients are at risk for developing the syndrome if they have one or more of the following:

• BMI is < 16 kg/m².
• Unintentional weight loss >15% in the last 3-6 months.
• Little or no nutrition intake for > 10 days.
• Low potassium phosphate or magnesium levels before feeding.

Or it may occur if the patients have any 2 of the following:

• BMI is <18.5 kg/m².
• Unintentional weight loss >10% within the last 3-6 months.
• Little or no nutritional intake for more than 5 days.
• History of alcohol abuse 
• Medication like insulin, chemotherapy, antacids, or diuretics

Epidemiology of Refeeding Syndrome

As eating disorders are seen more commonly in females, refeeding syndrome is more common in the female population than in the male population.

Pathophysiology of Refeeding Syndrome

During rapid and excessive nutritional support, massive insulin release occurs, causing a shift in fluids and electrolytes and increasing the intracellular uptake of electrolytes. The hallmark of the refeeding syndrome is hypophosphatemia.

Apart from that, there can be decreased calcium, magnesium, zinc, and potassium levels. To get a differential diagnosis of acute alcoholism, thiamine levels should be tested. In acute alcoholism, there is also an acute deficiency of thiamine. 

Risk factors for developing Refeeding Syndrome

• Presence of altered myocardial functions and arrhythmias.
• Cardiac pathology/events are the most common cause of mortality.
• Seizures, confusion, and coma
• Liver dysfunction
• Presence of tetany, respiratory failure
• Thiamine deficiency can lead to Wet Beri Beri

Prevention and Treatment of Refeeding Syndrome

• Avoid rapid and excessive feeding.
• Correct electrolyte imbalance before feeding.
• Provide vitamin supplementation accordingly.
• Thiamine deficiency should be corrected prior to the feeding. 
• Calorie delivery should be 10kCal/kg/day.
• It should be increased gradually in 4-7 days.
• The calorie requirement should be matched with the intake and the required rate.

Special situations in artificial nutrition

• Pulmonary failure
  • Whether nutrients should be increased or decreased depends on the respiratory quotient (RQ).
  • The RQ of carbohydrate is 1, fat is 0.7, and protein is 0.8.
  • If carbohydrates are provided, they will produce a maximum amount of carbon dioxide during metabolism.
  • If a carbohydrate is given to patients with COPD and respiratory distress, it will produce more carbon dioxide, making it difficult to wean the patient off the ventilator.
  • In patients with pulmonary failure, low carbohydrates should be given.
  • Low osmolarity fluids should be given.
  • Fat content can be increased because it has the lowest RQ.
• In case of renal failure, lower fluid volume with a high non-calorie protein-to-nitrogen ratio should be ensured.
  • However, the current guidelines require a standard formula to be administered to the patients.
• In hepatic failure, the protein intake should be within 20-40gm/day, and the nutrition should contain more branched-chain amino acids (>50%).

Frequently Asked Questions:

Q: What is the hallmark of Refeeding Syndrome?

Answer: The hallmark of the refeeding syndrome is hypophosphatemia.

Q: The deficiency of which vitamin causes Wernicke’s Encephalopathy?

Answer: Thiamine

Q: How much time does it take for Refeeding Syndrome to start?

Answer: it usually starts between 24-72 of refeeding.

Q: In case of malnutrition, is it necessary to give the patient vitamins?

Answer: Yes, it is very important to give vitamins as they help to prevent neurological problems like encephalopathies.

Also Read: Artificial Nutritional Support

High-Yield GIT, Hepatobiliary and Pancreatic Surgery Questions

Hope you found this blog helpful for your NEET SS Surgery Perioperative preparation. For more informative and interesting posts like these, keep reading PrepLadder’s blogs.