Propofol Combined with Halothane or with Fentanyl/Halothane Does Not Alter the Rate of CSF Formation or Resistance to Reabsorption of CSF in Rabbits

Abstract

A previous study of the cerebral effects of propofol reported that the propofol caused an initial decrease of cerebrospinal fluid (CSF) pressure and cerebral blood flow, followed by a return of CSF pressure to control values despite continued administration of propofol and continued decrease of cerebral blood flow. One explanation for the return of CSF pressure to control values is that propofol may cause an increase of the rate of CSF formation or of resistance to reabsorption of CSF. The present study was designed to examine the effects of low, moderate, and high doses of propofol, given with either fentanyl or halothane, on the rate of CSF formation and resistance to reabsorption of CSF. The rate of CSF formation and resistance to reabsorption of CSF were determined in 12 rabbits using the technique of ventriculocisternal perfusion. In the propofol-fentanyl group (n = 6), the fentanyl dose was 100 micrograms/kg followed by 20 micrograms x kg-1 x h-1 i.v., and in the propofol-halothane group (n = 6), the concentration of halothane was 0.8 to 1.0%. For both groups, the three doses of propofol were 6 mg/kg followed by 12 mg x kg-1 x h-1, 24 mg x kg-1 x h-1, and 48 mg x kg-1 x h-1 i.v., respectively. In both groups, propofol caused no significant change of the rate of CSF formation or resistance to reabsorption of CSF.(ABSTRACT TRUNCATED AT 250 WORDS)