Impairment of cognitive functions, including memory, learning, concentration, and speed of mental processing, emerging days or weeks after major surgery, especially in elderly patients. The condition may persist for months or years, long-term effects being especially common after cardiac surgery with use of heart-lung machines, as was noted soon after such machines were introduced. The first large-scale study of the condition after non-cardiac surgery was the International Study of Postoperative Cognitive Dysfunction (ISPOCD), initially reported in the journal The Lancet in 1998, confirming that anaesthesia and surgery cause long-term post-operative cognitive decline in some elderly patients having major, elective, non-cardiac surgery and that the risk increases with age. The term itself first appeared in print in an article by the US psychiatrist David G. Folks (born 1953) and several colleagues in the Southern Medical Journal in 1988. See also cognitive impairment, pumphead. POCD abbrev.