Dexmedetomedine vs midazolam sedation in middle ear surgery under local anesthesia: Effect on surgical field and patient satisfaction

Background
A relatively bloodless microscopic field is essential to facilitate surgical exposure in Simple Middle Ear Surgery (SMES). Our aim was to compare dexmedetomedine with midazolam in reducing bleeding in SMES performed under local anesthesia.
Methods
In this prospective, double-blind, comparative study, 54 patients undergoing SMES randomly received intravenous sedative infusion of either: Dexmedetomedine (Group D) or midazolam (Group M) titrated to a bispectral index reading of 70–80. Pain on local anesthesia injection was assessed by a verbal rating scale. Using a 3-grades score, the surgeon assessed the quality of surgical bleeding. Mean Arterial Pressure (MAP) and Heart Rate (HR) were assessed. Time parameters recorded include: time to reach adequate sedation, surgery duration, sedation recovery and postanesthesia care unit discharge. Patient satisfaction, visual analog scale for intraoperative pain, and number of patients required rescue fentanyl were recorded. Adverse effects were also recorded.
Results
Surgical field bleeding score was significantly better in group D compared to group M (Grade I: 18 vs 4, Grade II: 9 vs 19, Grade III: 0 vs 4, respectively)  < 0.001. Intraoperative MAP and HR in group D were lower than their baseline values and the corresponding values in group M. Group M patients were earlier to reach adequate sedation level than those of group D, but they felt more pain either on local anesthetic injection or during operation. Rescue fentanyl was needed only for group M patients. Patient satisfaction was higher in group D. Time of surgery was longer in group M. Both groups were similar in sedation recovery and ward discharge times, as well as, incidence of side effects.
Conclusion
Compared to midazolam sedation in SMES performed under local anesthesia, Dexmedetomedine was associated with a near bloodless microscopic surgical field, shorter surgery time, greater patient satisfaction, and lower pain scores with no adverse effects.