Effects of osmotic and oncodiuretic therapy on CT-brain density and intracranial pressure

This study was performed to determine the effects of osmotic and oncodiuretic therapy on CT-brain density (CT-BD) and on intracranial pressure (ICP) in normal monkeys. CT scans were obtained before therapy then hourly for six hours. ICP was measured before therapy and was continuously monitored thereafter. Four monkeys in group I received oncodiuretic therapy (furosemide-albumin) for the first five hours, then osmotic therapy (mannitol) was added for one hour. Four monkeys in group II received mannitol during the first hour of therapy, then oncodiuretic therapy was added for the remaining four hours. CT-BD was increased and ICP decreased one hour after mannitol but not after oncodiuretic therapy. CT-BD and ICP correlated inversely during osmotic therapy but not during oncodiuretic therapy. The effects of mannitol on CT-BD indicate that it lowers ICP by dehydrating normal brain. Oncodiuretic therapy did not reduce ICP nor consistently increase CT-BD in these six hour experiments on monkeys without cerebral oedema.