Effect of propofol on brain retraction pressure and cerebral perfusion pressure

We have studied the effect of propofol, at a rate of 30 mg kg-1 h-1 for 5 min reducing to 6 mg kg-1 h-1 for a further 5 min, on brain retraction pressure (BRP) in 15 patients undergoing craniotomy. The response of BRP showed two distinct patterns. BRP was reduced by an average of 3.3 mm Hg (P = 0.005). Mean arterial pressure was reduced in all patients by an average maximum of 28.3 mm Hg (P = less than 0.001), which caused a significant reduction in cerebral perfusion pressure (CPP) by 22.9 mm Hg (P less than 0.001). It is concluded that, by reducing BRP, propofol provided suitable conditions for intracranial surgery, but care should be taken to avoid excessive reduction in CPP.