Abstract
Background: Skull pin holder application during craniotomy can evoke stress response, which might lead to sudden rise in blood pressure (BP), causing intracranial hemorrhage, cerebral edema, and prolonged hospital stay. Dexmedetomidine has been shown to blunt the sympathoadrenal response to surgery.

Aims and Objectives: The present study was undertaken to assess the efficacy and safety of dexmedetomidine in attenuating stress responses to skull pin holder application as compared to normal saline.

Materials and Methods: After obtaining approval from the institutional ethics committee and written informed consent, patients of either sex undergoing elective craniotomy at the attached hospitals of Bangalore Medical College and Research Institute, Bengaluru, India, were randomized in a 1:1 ratio to receive normal saline or dexmedetomidine as premedication. Hemodynamic parameters, i.e., heart rate (HR), systolic BP (SBP), diastolic BP (DBP), and mean arterial pressure (MAP), were monitored at various time points until 30 min after skull pin application. Data were analyzed using the chi-squared test, repeated measure ANOVA, unpaired t-test, and Mann–Whitney U test, wherever applicable.

Results: A total of 52 patients were included in the study, with 26 patients in each group. All the baseline parameters were matched. As a stress response, a significant increase in HR was seen after intubation (90.69 bpm) and skull pin insertion (87.92 bpm) in the normal saline group. However, there was no significant variation in HR in the dexmedetomidine group over 30 min (69.19 bpm–74.15 bpm). Dexmedetomidine reduced HR significantly as compared to normal saline after intubation (P = 0.03). Dexmedetomidine lowered SBP and DBP as compared to baseline throughout 30 min without any excursions during intubation and skull pin insertion. The SBP was significantly lower in the dexmedetomidine group after intubation as compared to saline (P = 0.02). Although a reduction in SBP was noted after skull pin insertion in the dexmedetomidine group, it was not statistically significant than saline. No significant difference was noted in DBP, MAP, or blood glucose between the two groups. No incidents of hypotension and bradycardia were noted.

Conclusion: Dexmedetomidine maintained basal HR throughout 30 min without any variations in response to intubation and skull pin insertion. It also reduced SBP and DBP over 30 min. HR and SBP were significantly lower in the dexmedetomidine group as compared to saline after intubation. The same effect was noted in the dexmedetomidine group as compared to saline after skull pin insertion, but it was not statistically significant.

Key words: Dexmedetomidine; Craniotomy; Stress Response; Skull Pin Holder; Hemodynamic Parameters; Heart Rate; Blood Pressure