EFFECTS OF DIASPIRIN CROSS-LINKED HEMOGLOBIN ON POSTTRAUMATIC CEREBRAL PERFUSION-PRESSURE AND BLOOD-FLOW IN A RODENT MODEL OF DIFFUSE BRAININJURY

Diaspirin cross-linked haemoglobin (DCLHb) is a new oxygen carrying bl ood substitute with vasoactive properties. Vasoactive properties may b e mediated via high affinity binding of nitric oxide by the haem moiet y. Using a rodent model of head injury combined with ischaemia, we stu died the effects of DCLHb on cerebral blood flow (CBF) and intracrania l pressure (ICP). Twenty anaesthetized rats were allocated randomly to receive treatment with DCLHb 400 mg kg(-1) i.v. or placebo (oncotical ly matched plasma protein substitute 4.5% i.v.). To produce diffusely increased ICP, after a severe weight drop injury, all animals underwen t a 30-min period of bilateral carotid ligation combined with a period of induced hypotension. After reperfusion, DCLHb or placebo was infus ed and the animals instrumented for measurement of intraventricular IC P and CBF in the region of the sensorimotor cortex using the hydrogen clearance technique. Mean arterial pressure (MAP), ICP, cerebral perfu sion pressure (CPP) (CPP=MAP-ICP) and CBF were measured 4 h after inju ry in all animals. DCLHb significantly reduced ICP from mean 13 (SEM 2 ) to 3 (1) mm Hg (P<0.001), increased CPP from 52 (8) to 95 (6) mm Hg (P<0.001) and increased CBF from 21 (2) to 29 (2) ml 100 g(-1) min(-1) (P=0.032). We conclude that DCLHb improved CPP without a reduction in CBF in a rodent model of post-traumatic brain swelling.