Early hemodynamic injury during donor brain death determines the severity of primary graft dysfunction after lung transplantation.

Sympathetic discharge and hypertensive crisis often accompany brain death, causing neurogenic pulmonary edema. Progressive systemic inflammatory response develops, which can injure the lung further. We investigated whether (a) early hemodynamic injury during donor brain death increases reperfusion injury after lung transplantation and (b) delaying lung recovery would augment reperfusion injury further, because of the progressive systemic inflammatory response in the donor. Brain death was induced by intracranial balloon inflation in rats, with or without alpha-adrenergic blockade pretreatment to prevent the hypertensive crisis. Another group of rats had a sham procedure. Lungs were retrieved 15 min after brain death or sham procedure and reperfused using recipient rats. In a fourth group, brain death was induced and the lungs were retrieved 5 h after brain death and reperfused. Postreperfusion, lungs retrieved early from untreated brain-dead donors developed more severe reperfusion injury, as assessed by functional parameters and inflammatory markers, than those from sham or alpha-blockade-treated donors. Lungs retrieved late from brain-dead donors had similar inflammatory markers after reperfusion to those retrieved early, but significantly lower pulmonary vascular resistance. Early hemodynamic damage during donor brain death increases reperfusion injury after lung transplantation. Delaying retrieval may allow the lung to recover from the hemodynamic injury.

A solution to the binding problem? Information processing.

The brain effortlessly recombines information about the shape, colour, motion and so on of objects in the visual scene, but how it does so is not known. Synchronous neuronal firing has seemed an attractive solution to this problem, but new results and theoretical insights cast doubt on its functional role.