Efficacy of Dexmedetomidine as an Adjuvant to Local Anesthetic Agent in Scalp Block and Scalp Infiltration to Control Postcraniotomy Pain: A Double-Blind Randomized Trial

Context: Scalp infiltration and scalp block are being used to manage postcraniotomy pain. Dexmedetomidine has been successfully used as an adjuvant in regional anesthesia. The study was intended to compare whether addition of dexmedetomidine prolonged the duration of analgesia as well as to compare the two techniques. Aims: The primary objective was to assess whether addition of dexmedetomidine to bupivacaine prolonged the duration of analgesia. The secondary objective was to compare between scalp nerve block and scalp infiltration as techniques for pain relief. Settings and Design: The randomized control study was conducted in a tertiary care center from November 2013 to October 2014. Materials and Methods: A total of 150 American Society of Anesthesiologists Physical Status I-II patients, aged 18-70 years undergoing elective craniotomy were included. Patients were randomized into three groups of 50 patients, i.e., Group BI (bupivacaine infiltration), Group BDI (bupivacaine and dexmedetomidine infiltration), and Group BDNB (bupivacaine and dexmedetomidine scalp nerve block). Patient's pain score, pain-free interval, rescue analgesic requirement, and hemodynamic and respiratory parameters were noted for 48 h. Patients were followed up at 1 and 3 months to assess postcraniotomy pain. Results: Pain-free period was significantly longer in Group BDNB than Groups BDI and BI (P < 0.0001) and pain control was better in dexmedetomidine containing groups than in bupivacaine group (BI) (P < 0.0001). The rescue analgesic requirement was significantly lower in Group BDNB and Group BDI compared to Group BI. Conclusion: The addition of dexmedetomidine (1 mu g/kg) to bupivacaine prolonged the pain-free period. Scalp nerve block is a superior technique than scalp infiltration.