Effect of propofol on cerebrospinal fluid pressure and cerebral perfusion pressure in patients undergoing craniotomy.

The effects of propofol on cerebrospinal fluid pressure, mean arterial pressure, cerebral perfusion pressure and heart rate were studied during induction, tracheal intubation and skin incision in 23 patients scheduled for elective craniotomy. Premedication consisted of midazolam 0.1 mg/kg intramuscularly and metoprolol 1 mg/kg orally. Measurements were made or derived at time zero and 0.5, 1, 1.5, 2 and 3 minutes after an induction dose of propofol 1.5 mg/kg. A continuous infusion of propofol was started at time zero at a rate of 100 mg/kg/minute. Fentanyl 2 micrograms/kg was added before tracheal intubation, application of the pin head holder and skin incision. Cerebrospinal fluid pressure and mean arterial pressure decreased significantly 2 minutes after propofol alone, by 32% and 10% respectively, while a cerebral perfusion pressure above 70 mmHg was maintained. Heart rate did not change. Propofol combined with moderate dose of fentanyl, obtunded the usual cerebrospinal fluid and arterial pressure responses to intubation and other noxious stimuli. Thus propofol seems to be a suitable intravenous anaesthetic agent for induction and maintenance in neuroanaesthesia.