Comparison of dexmedetomidine and fentanyl to prevent haemodynamic response to skull pin application in neurosurgery: double blind randomized controlled trial.

BACKGROUND: Skull pin application during craniotomy is a highly noxious stimulus. Therefore, the attenuated effect between dexmedetomidine and fentanyl was investigated.

METHOD: A randomized, double-blind controlled trial included sixty patients, randomly allocated into groups A and B. After patients entered the operative room, blood pressure and heart rate were measured (T1). At 5 minutes after propofol induction (T2), group A received dexmedetomidine 1 µg kg⁻¹ whereas group B received normal saline. At 3 minutes before skull pin insertion (T3), group B received a single bolus of fentanyl 1 µg kg⁻¹ whereas group A received normal saline. The hemodynamic responses were recorded at 1 minute before skull pin insertion (T4), during skull pin insertion (T5), then repeated every minute for 5 minutes (T6-T10).

RESULTS: Controlling blood pressure in the dexmedetomidine group (Group A) was better than in the fentanyl group (Group B) at T4 and T10 (P < 0.05) and T5-T8 (P < 0.01) for systolic blood pressure whereas diastolic blood pressure was significantly different at T4 and T8 (P < 0.05) and T5-T7 (P < 0.01). Mean arterial pressure, also was better controlled in group A at T4 and T10 (P < 0.05) and T5-T8 (P < 0.01). The heart rate in group A was lower than group B at T9 (P < 0.05) and T3-T6 (P < 0.01). Regarding adverse events, 11 hypertensive and 2 hypotensive responses occurred in group B whereas group A just only had 7 incidences of hypotension.

CONCLUSION: The attenuated effect of dexmedetomidine infusion is significantly greater than fentanyl infusion.