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

Abstract

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.

Effect of Diprivan on Intracranial Pressure in Patients with Head Injuries

“…The dif ferences between the two studies may be due to technical differences; the previous study used only 6.0 patients who received diprivan over 90 s and ICP was measured using an intraventricular pressure monitor. In patients undergoing intracranial surgery (for aneu rysm or tumours) ICP was reduced after in duction of anaesthesia with diprivan 1.5 mg/ kg [5] and 0.35 and 0.8 mg/kg [6], which agrees with our results. The fact that Ravussin et al [5] reported no significant change in CPP may arise because they measured cere brospinal fluid (CSF) pressure as a measure of ICP which can be inaccurate.…”

Assessment of Haemodynamic Response to Induction of General Anaesthesia in Healthy Adult Patients Undergoing Elective Orthopaedic Surgery by Using a Continuous Non-invasive Cardiovascular Monitoring

“…MAP and intracranial pressure (ICP) are both parameters required to calculate the CPP (CPP = MAP -ICP). In a study by Ravussin et al [17], a significant decrease in ICP was noted after propofol induction. The fall in MAP in our study may have counted towards a decrease in CPP and contributed to further cortical depression.…”

Changing practices in neuroanaesthesia

“…56 '57 Stephan et al 57 observed average CBF and CMR decreases of 51 and 36 per cent respectively after administration of propofol by bolus plus infusion (2 mg.kg -I and 0.2 mg.kg-t.min-~). Ravussin et al 58 measured lumbar CSF pressure during induction of anaesthesia by slow bolus administration of propofol (I.5 mg-kg -~ over 30 sec) in patients about to undergo craniotomies. They reported mean maximum reductions in lumbar CSFP and CPP of 32 and 10 per cent respectively.…”