What is refeeding syndrome?
It was first recorded in the 1940s, when prisoners of war were released from camps, many of them having survived starvation, ate too much too fast and subsequently died.
Refeeding syndrome involves metabolic abnormalities when a malnourished person begins feeding, after a period of starvation or limited intake. In a starved body, there is a breakdown of fat and muscle, which leads to losses in some electrolytes like potassium, magnesium, and phosphate. These electrolyte levels do not always appear to be low in the blood because our bodies try to preserve them through fewer losses by our kidneys. When a person re-starts feeding, these electrolyte levels shift into the cells causing blood levels to drop.
What are the symptoms of refeeding syndrome?
Some of the symptoms include:
- Severe hypophosphatemia (<0.4 mmol/L): CHF, arrhythmias, confusion, seizures
- Severe hypomagnesemia (<0.4 mmol/L):arrhythmias, tachycardia, diarrhea, seizures, hypocalcemia
- Severe hypokalemia (<2.5 mmol/L): ileus, cardiac arrest, arrhythmias, paralysis, respiratory depression
- Fluid excess (i.e. rapid weight gains, changes in serum sodium, increased blood pressure and pulse)
Who is at risk of developing refeeding syndrome?
People at risk include patients with protein-energy malnutrition, alcohol abuse, anorexia nervosa, prolonged fasting, no nutritional intake for seven days or more, and significant weight loss. There are also studies that indicate the refeeding syndrome may develop after as little as 48 hours with no nutritional intake.
What were the results of this study?
It is often thought that enteral feeding should be initiated slowly in those who are severely malnourished. A descriptive study completed at the Richmond Hospital examined the effect of an enteral feeding protocol on the typical metabolic consequences seen in refeeding syndrome. A retrospective chart review of 51 patients placed on hospital-wide enteral feeding and electrolyte replacement protocols over a nine-month period, tried to determine whether there were any negative clinical consequences to early feeding.
The goal tube-feeding rate was achieved within 17.6 ± 8.7 hours. Forty patients (80%) developed depletions in phosphate, magnesium, and/or potassium following initiation of enteral feeding. All patients received electrolyte replacement according to protocols and no patients showed any negative clinical effect. This study showed that malnourished patients at risk for refeeding syndrome could be fed early without observed clinical consequences. An electrolyte replacement protocol may be an effective means of minimizing the electrolyte imbalances associated with early feeding. Given that 74% of these patients were deemed not at risk of refeeding syndrome at the beginning of the study, it also demonstrated the significance if applying such protocols to all patients requiring entreal support.