The effect of dexmedetomidine on bispectral index monitoring in children.
The primary aim of this study was to test whether dexmedetomidine administration based on the bispectral index (BIS) monitoring caused a reduction in consumption of sevoflurane. Following Institutional Ethic Committee approval and written informed consent from all parents, fifty-four children undergoing sevoflurane anaesthesia randomly allocated to receive either dexmedetomidine (Group D) or saline (Group S). The anaesthesia was induced with 8% sevoflurane in nitrous oxide/oxygen in all children. Following anaesthesia induction, Group D (n=27) children received a loading dose of dexmedetomidine 1 microgkg(-1) IV over ten minutes, followed by a continuous infusion at a rate of 0.5 microgkg(-1) hr(-1) throughout the surgery. Group S (n = 27) children received same volume of saline infusion due to obtained blindness. Systolic blood pressure (SBP), diastolic blood pressure (DBP), heart rate (HR), body temperature and peripheral oxygen saturation (SpO2), end-tidal concentrations of oxygen, carbon dioxide (ETCO2), and sevoflurane (ETsevo) were monitorized. Bispectral index numbers and ETsevo concentrations were recorded at 2 min before incision, 2 min after incision, at the end of surgery and before the termination of anaesthesia, and finally immediately after wake-up from anaesthesia (Final BIS number). BIS number was found significantly lower in group D at before incision, after incision and at the end of surgery than in group S (p = 0.000, 0.001, 0.007). End tidal sevoflurane concentrations were significantly higher in group S at before incision, after incision and at the end of surgery than in group D (p < 0.000 to p < 0.001). Final BIS number and sevoflurane concentrations were similar and there were no significant difference between the groups. It was concluded that intravenous (IV) dexmedetomidine infusion at a rate of 0.5 microgkg(-1) hr(-1) during sevoflurane anaesthesia significantly reduces end-tidal sevoflurane concentration and BIS number in children undergoing minor surgical interventions.