Sevoflurane and propofol are widely used for induction and maintenance of general anesthesia. Although the effects of sevoflurane and propofol on cerebral hemodynamics during maintenance of general anesthesia have been demonstrated, the effects during induction of general anesthesia have still not been clarified. We therefore compared changes in cerebral blood flow (CBF) and oxygenation (CBO) during induction of anesthesia using sevoflurane (group S: n=9) or propofol (group P: n=9). CBF and CBO were evaluated using the following variables: oxy-, deoxy-, and total-hemoglobin (Hb) concentrations and tissue oxygen index (TOI), measured on the forehead by near-infrared spectroscopy. The variables were recorded immediately before administration of sevoflurane or propofol and at every 10 s for 4 min after administration of the induction agent. Patients received 8% sevoflurane in 100% oxygen via an anesthesia mask in group S, and an IV bolus of 2 mg/kg of propofol during oxygenation in group P. We found that oxy-Hb, total-Hb, and TOI were significantly higher in group S than in group P (P>0.05). Changes in deoxy-Hb, MBP, and HR did not differ between the groups. The results of the present study demonstrated that sevoflurane increases CBF and CBO during induction of general anesthesia.
Keywords: Cerebral blood flow; General anesthesia; Near-infrared spectroscopy; Oxygenation; Sevoflurane, propofol.