A Randomized Controlled Study to Compare the Effectiveness of Intravenous Dexmedetomidine with Placebo to Attenuate the Haemodynamic and Neuroendocrine Responses to Fixation of Skull Pin Head Holder for Craniotomy

The stress response to an intense painful surgical stimulus is characterized by activation of the sympathetic nervous system and an increased secretion of the pituitary hormones. The ability of the alpha agonist dexmedetomidine was tested to decrease heart rate, arterial blood pressure, and neuroendocrinal responses to skull-pin head-holder. 60 patients undergoing craniotomy were randomly distributed to receive either saline (P group) or Dexmedetomidine (D group). The placebo group received saline, whereas the treatment group (D group) received a single bolus dose of dexmedetomidine (1 microgram/kg) intravenously over 10 minutes before induction of anaesthesia. Haemodynamic parameters as heart rate, arterial blood pressure, and serial levels of cortisol, prolactin, insulin, and blood glucose were measured. Both the groups were comparable with respect to age, weight, sex and duration of surgery. The arterial blood pressure and heart rate was found to be lower in the dexmedetomidine group when compared with the placebo group (P<0.05). In both groups there was an increase in the plasma cortisol, prolactin, and blood glucose levels. However, the values were significantly higher in the placebo group compared with the dexmedetomidine group (P<0.05). The insulin levels were not significantly changed because of the administration of the dexmedetomidine. Our study demonstrates that, a single bolus dose of dexmedetomidine before induction of anesthesia attenuated the hemodynamic and neuroendocrinal responses to skull-pin insertion in patients undergoing craniotomy.