Warm ischemia in transplantation: Search for a consensus definition

Warm ischemia is a term used to describe ischemia of cells and tissues under normothermic conditions. In the transplant setting, this term is used to describe two physiologically distinct periods of ischaemia: (1) Ischemia during implantation, from removal of the organ from ice until reperfusion, and (2) Ischemia during organ retrieval, from the time of cross clamping (or of asystole in non-heart-beating donors), until cold perfusion is commenced. These periods of warm ischemia differ in their nature and the magnitude of their pathophysiologic consequences. In much transplant literature, however, the term warm ischaemia is used to describe both of these periods indiscriminately. This paper attempts to produce a definition to distinguish between the two periods of warm ischemia.