Refeeding syndrome: screening, incidence, and treatment during parenteral nutrition.

The possible deleterious effects of feeding after a period of prolonged starvation have been known for over 60 years. The resultant biochemical disturbance, symptoms, and signs have been termed the refeeding syndrome (RS). The key to the pathophysiology is the stimulation of insulin release resulting in anabolic activity. Depleted electrolyte and micronutrient stores are overwhelmed and cellular function disrupted. A concise definition of RS is not agreed and hampers interpretation of clinical data. Hypophosphatemia and appearance of tissue edema/pathological fluid shifts are the most often agreed diagnostic criteria. The characteristics of particular patient groups at risk have been recognized for some time, and there are guidelines from the National Institute for Clinical Excellence in the UK to aid recognition of individuals at high risk along with protocols for initiating nutrition. Using loose diagnostic criteria, RS appears to occur in 4% of cases of parenteral nutrition (PN) when case records were reviewed by experts in a large study into PN care in the UK. Disappointingly, prescribers recognized only 50% of at risk cases. Early data from a similar study in New Zealand appear to show a similar pattern. Prospective series looking at patients receiving nutrition support in institutions with Nutrition Support Teams have found an incidence of 1-5%. RS is still underrecognized. Patients receiving PN should be counted as being in a high-risk category and feeding protocols to avoid RS applied. Low rates of RS then occur and death from this cause be avoided.