Dexmedetomidine as an anaesthetic adjuvant in patients undergoing intracranial tumour surgery: a double-blind, randomized and placebo-controlled study

Background. Dexmedetomidine (DEX) has been shown to providegood perioperative haemodynamic stability with decreased intraoperativeopioid requirements. It may have neural protective effects,and thus may be a suitable anaesthetic adjuvant to neurosurgicalanaesthesia. Methods. Fifty-four patients scheduled for elective surgeryof supratentorial brain tumour were randomized to receive ina double-blind manner a continuous DEX infusion (plasma targetconcentration 0.2 or 0.4 ng ml^–1) or placebo, beginning20 min before anaesthesia and continuing until the start ofskin closure. The DEX groups received fentanyl 2 µg kg^–1at the induction of anaesthesia and before the start of operation,the placebo group 4 µg kg^–1, respectively. Anaesthesiawas maintained with nitrous oxide in oxygen and isoflurane. Results. The median times from the termination of N₂O to extubationwere 6 (3–27), 3 (0–20) and 4 (0–13) min inplacebo, DEX-0.2 and DEX-0.4 groups, respectively (P<0.05ANOVA all-over effect). The median percentage of time pointswhen systolic blood pressure was within more or less than 20%of the intraoperative mean was 72, 77 and 85, respectively (P<0.01),DEX-0.4 group differed significantly from the other groups.DEX blunted the tachycardic response to intubation (P<0.01)and the hypertensive response to extubation (P<0.01). DEX-0.4group differed in the heart rate variability from placebo (93vs 82%, P<0.01). Conclusions. DEX increased perioperative haemodynamic stabilityin patients undergoing brain tumour surgery. Compared with fentanyl,the trachea was intubated faster without respiratory depression.