ul><li>Re-feeding syndrome occurs in previously malnourished patients who are fed with high carbohydrate loads. </li><li>Carbohydrates (eg, glucose) in the feed can cause a large increase in the circulating insulin level. This results in a rapid and dramatic fall in phosphate, potassium and magnesium - with an increasing extracellular fluid (ECF) volume. </li><li>As the body tries to switch from catabolic (starvation mode) to using exogenous fuel sources, there is an increase in oxygen consumption, increased respiratory and cardiac workload (may precipitate acute heart failure and tachypnoea and make weaning from a ventilator difficult). Demand for nutrients and oxygen may outstrip supply. Both of the above can lead to multiple organ failure; respiratory and/or cardiac failure, arrhythmias, rhabdomyolysis, seizures or coma, red cell and/or leukocyte dysfunction. </li><li>The gut may have undergone some atrophy with starvation and, with the return of enteral feeding, there may be intolerance to the feed, with nausea and diarrhoea. </li><li>Feeds should be started slowly and the electrolytes closely monitored and adequately replaced to avoid these problems developing.</li></ul