Effect of Dexmedetomidine on Postoperative Hemodynamics and Outcome of Free Flaps in Head and Neck Reconstructive Surgeries

Abstract

Background and Aims: Dexmedetomidine is less frequently used during free flap surgeries for fear of causing vasoconstriction leading to flap failure as it is an α2 agonist. But most patients following major resections with free flap reconstruction develop uncontrolled hypertension postoperatively which could lead to complications resulting in reduced flap perfusion. We aimed to compare the effects of dexmedetomidine on postop haemodynamics, re-exploration rates and final outcome of free flaps in patients who underwent reconstructive surgeries. Material and Methods: This prospective, randomized study was conducted in 40 patients aged 20-70 years. Patients in both groups received morphine 0.1mg/kg, 30 minutes before end of surgery. In addition, in Group D dexmedetomidine 1mcg/kg bolus was also given at the same time, followed by 0.5mcg/kg/hr infusion. Post operatively the patients received either dexmedetomidine 0.5mcg/kg/h (Group D) or morphine 2mg/hr (Group M) infusion for 12 hours. Statistical analysis was done using Chi-Square test and independent sample t test. Results: Morphine group had significantly higher heart rate (105.2 ± 7.5 vs 90.0 ± 11.7), systolic blood pressure (167.5 ± 7.3 vs 125.4 ±16.6) and mean arterial pressures (103.5 ± 4.6 vs 87.8 ± 12.2) than dexmedetomidine group. Same trend persisted till 12 hours post operatively. More patients in morphine group required re-exploration of the flap (15 vs 10%) and had flap failure (7.5 vs 2.5%), but these differences were not statistically significant. Conclusion: Dexmedetomidine can be safely used in patients with free flap reconstruction as it optimizes postoperative hemodynamics and is not associated with any significant increase in re-exploration or flap failures. Key Messages: Dexmedetomidine resulted in optimal postoperative hemodynamics, reduced re-exploration rate and better flap outcome.