Fentanyl versus Dexmedetomidine Infusion in Head and Neck Free Flap Surgery for Comparison of Hemodynamic Parameters and Anaesthetic Requirements: A Randomised Controlled Trial.

[BACKGROUND] This prospective, double-blinded, randomized study aimed to compare the efficacy of dexmedetomidine and fentanyl infusions in maintaining hemodynamics during head and neck free flap surgery, as well as their impact on the relative amount of blood loss.

[METHODS] Twenty patients with American Society of Anesthesiologists physical status I and II scheduled for elective head and neck free flap surgery were enrolled. The patients were randomly assigned to receive either dexmedetomidine (1 µg/kg over 10 min at anesthesia induction, followed by 0.2 to 0.75 µg/kg per hour infusion during maintenance) or fentanyl (1 to 2 µg/kg per hour infusion during maintenance). Intraoperative hemodynamic parameters, blood loss, blood transfusion requirements, surgeon satisfaction, adverse drug effects, and free flap survival up to 7 days were recorded.

[RESULTS] The dexmedetomidine group achieved a mean arterial pressure (MAP) value between 60 and 70 mmHg at multiple time points (15 min, 3rd, 4th, 5th, and 6th hours), while the fentanyl group did not reach this range at any time point. The intergroup statistical analysis revealed a significant difference only at the 5th hour with (95% CI: -16.17 to -0.62) and  = 0.036. Additionally, the dexmedetomidine group exhibited lower heart rates (< 70/min) at several time points (15 min, 2nd, 3rd, 4th, 5th, and 6th hours) compared to the fentanyl group. The intergroup comparison indicated a statistically significant difference only at the 3rd hour with (95% CI: -20.94 to -0.45) and  = 0.042.

[CONCLUSION] Dexmedetomidine can be a useful adjuvant of GA for inducing controlled hypotension and decreasing bleeding in free flap surgery of the head and neck region without any detrimental effect on the free flap survival.