Postoperative encephalopathy with choreoathetosis.

Since the 1980s, survival of children with CHD has increased significantly with the introduction of new surgical techniques that incorporate cardiorespiratory arrest (CRA), extracorporeal circulation (ECC), and deep hypothermia. However, an increase in survival has been associated with an increase in recognized postoperative neurological complications. Postoperative encephalopathy with choreoathetosis, also known as "postpump chorea", is one of these well-defined neurological complications and was first reported in 1961. Postpump chorea is considered one of the most devastating neurological complications following cardiac surgery. However, the exact etiology and pathophysiology of this complication is unknown. Several factors may contribute to the postoperative development of choreoathetoid movements, including deep hypothermia (core body temperature < 20ºC) with total circulatory arrest, use of cardiopulmonary bypass, and variability in blood pH and PaCO(2) resulting in fluctuations in cerebral blood flow. The length of time children are affected by choreoathetoid movements and long-term neurological outcome in these children varies and largely depends upon the form of postoperative encephalopathy that they develop, described as either mild or severe. Several groups suggest that age at time of surgery plays a role in the risk of developing postpump chorea, with a tendency for older children to develop the severe persistent form.