To compare the effect between dexmedetomidine and fentanyl for controlling the hemodynamic response to skull pins application

A randomized, double-blinded controlled trial was conducted from September 2015 to September 2016 in Srinagarind Hospital, Faculty of Medicine, Khon Kaen University, Thailand. Sixty patients who underwent craniotomy with insertion of skull pin were randomly allocated into group A and B. After patients entered the operative room, blood pressure and heart rate were measured (T1) then repeated measurement again (T2) when started induction, intubation and infusion dexmedetomidine 1 µg/kg over 10 min infusion in group A whereas group B received normal saline. At 3 minutes before skull pin insertion (T3), patient in group B received a single bolus of fentanyl 1 µg/kg whereas group A received normal saline. Then hemodynamic responses were recorded and repeated again at one minute before skull pin insertion (T4). Blood pressure and heart rate were observed at the time of skull pin insertion (T5) then repeated every 1 minutes after skull pin application until 5 minutes (T6 - T10).

Inclusion Criteria:

• patients who scheduled for elective craniotomy under general anesthesia
• patient with American Society of Anesthesiologists physical status classification of I and II

Exclusion Criteria:

• patients having body mass index more than 30 kg/m2, heart rate lower than 45 bpm, hypertension, ischemic heart disease, heart block, on beta adrenergic blockers, medication allergy including propofol, fentanyl, and dexmedetomidine.

After written informed consents were obtained, all participant was blinded from the study drug. The study drugs (dexmedetomidine and fentanyl) were prepared by anesthetist nurse who not involved in the study. Dexmedetomidine was labeled with group A whereas fentanyl was labeled with group B. The study drug was administrated by the blinded anesthiologist. Blood pressure, mean arterial pressure, and heart rate were recorded by same blinded anesthesiologist