Background
Dexmedetomidine is an α-2 adrenoceptor agonist with sedative and analgesic properties. Desflurane is the most rapidly washed volatile anesthetic agent allowing rapid recovery with minimal metabolism. Having a MAC of 6 vol % made it important to look for an adjuvant that would minimize its consumption. This study was undertaken to analyze desflurane consumption when combined with dexmedetomidine infusion guided by bispectral index as well as calculating intraoperative fentanyl requirements and recording hemodynamic changes associated with this technique.
Methods
Forty adult patients ASA class I and II of either sex scheduled for elective laparoscopic cholecystectomy were included in this study. Patients were randomized to one of two groups: Group ‘D’ (Dexmedetomidine group) receiving 1μg/kg over 10 minutes followed by an infusion at 0.5 μg/kg/hr and Group ‘P’ (Placebo group) who received same volumes of normal saline. Desflurane was started at a concentration of 6% then adjusted to keep BIS level within the range of 40-50. Desflurane consumption, fentanyl requirements as well as hemodynamics were either calculated or recorded.
Results
Desflurane consumption and total fentanyl usage were significantly lower in group D versus group P with value < 0.001. As regards hemodynamics, group D showed statistically significant lower readings versus the preoperative levels (<0.05) as well as versus group P at the same timings (<0.05) for most of the readings.
Conclusions
Continuous intravenous administration of dexmedetomidine resulted in significant reduction of desflurane consumption and intraoperative fentanyl requirements with attenuation of hemodynamic response to intubation, pneumoperitoneum and extubation.