Relationship between Cerebral Blood Volume and CSF Pressure during Anesthesia with Halothane or Enflurane in Dogs

Abstract

Cerebral blood volume (CBV) and intracranial pressure (ICP) were examined in dogs during 3.5 h anesthesia with halothane (0.8%) or enflurane (2.2%), and after decreasing the concentration of halothane to < 0.1% or enflurane to < 0.2%. As compared with animals breathing N2O and O2, halothane (0.8%) increased CBV 11-12%, while ICP remained increased (4-5 cmH2O) for 3.5 h. Both at 0.8% and < 0.1% ICP correlated positively with changes in CBV. Enflurane (2.2%) increased CBV by 8-10%, and while ICP correlated with changes in CBV during the initial 30 min, ICP increased independently of CBV thereafter.