Refeeding syndrome is defined by the American Society for Parenteral and Enteral Nutrition (ASPEN) committee as “a measurable reduction in levels of one or any combination of phosphorus, potassium, and/or magnesium, or the manifestation of thiamine deficiency, developing shortly (hours or days) after the initiation of calorie provision to an individual who has been exposed to a substantial period of undernourishment”. It is characterized by imbalances in sodium and fluid balance, hypophosphataemia, thiamine deficiency; hypokalaemia; and hypomagnesaemia and metabolic changes in glucose, protein, and fat. It mostly occurs in malnourished patients due to hormonal and metabolic changes and could lead to serious clinical complications. Refeeding syndrome is characterized by hypophosphataemia, abnormal sodium and fluid balance; metabolic changes in glucose, protein, and fat; thiamine deficiency; hypokalaemia; and hypomagnesaemia.^1,2

Besides the imbalances, other signs and symptoms include cardiac arrhythmias, heart failure, respiratory failure, intercostal and diaphragm muscle failure, failure to wean from the ventilatory, anaemia, immune dysfunction, Wernicke’s encephalopathy, and musculoskeletal weakness and rhabdomyolysis. Patients who are more at risk of developing refeeding syndrome include malnourished children with starvation physiology, children having inflammatory bowel disease anorexia nervosa, preterm infants and haematological cancers. Also, neonates who are premature and have very low birth weight may suffer from Refeeding syndrome.²

An optimum electrolyte balance is essential for a child’s proper and healthy growth. Potassium helps in the conduction of impulses in nerves, the excitability of muscles of skeletal, cardiac and smooth muscle. Almost 40% of critically ill children suffer from Hypokalaemia.. Magnesium is important for producing energy, helps in oxidative phosphorylation, and glycolysis helps in the structural development of bone and acts as a co-factor for different enzymes. Children suffering from hypomagnesemia were at greater risk of mortality and increases PICU stay compared. About 42% of children on PICU admission suffered from hypophosphatemia which increased the risk of the length of stay ICU. Mostly malnutrition and consumption of drugs like furosemide, dopamine, steroids and β2 agonist caused hypophosphatemia. Studies also revealed that 12.5-32% of patients among critically ill patients had low thiamine levels.²

Clinical studies related to the management of refeeding syndrome in children during critical illness are very few. Only one study disclosed that the refeeding syndrome was observed in 9%, critically ill children on paediatric nutrition. ASPEN had recommended and provided ways to manage and treat paediatric patients suffering from refeeding syndrome, but did not specific age.²

To conclude, it is important to manage and correct the electrolyte, fluid imbalances in critically ill children and bring it to normal levels. As recommended, to prevent refeeding syndrome in critically ill children, the energy intake should not exceed resting energy expenditure (REE) during the acute phase of critical illness. Further, the nutritional support should be increased in the PICU slowly after consulting with the nutrition support team.

References:

1. Hisham M Mehanna, J. M., Jane Travis, . Refeeding syndrome: what it is, and how to prevent and treat it. BMJ. 2008, 336(7659), 1495–1498.
2. Marino, L. V.; Jotterand Chaparro, C.; Moullet, C. Refeeding syndrome and other related issues in the paediatric intensive care unit. Pediatric Medicine 2020, 3.