Comparison of the Cardiovascular Response to Sedation with Dexmedetomidine, Midazolam, and Etomidate in Phacoemulsification under Local Topical Anesthesia; A Double-Blind Randomized Controlled Clinical Trial.

Background: The present study aimed to compare the cardiovascular response to sedation with dexmedetomidine, midazolam, and etomidate during phacoemulsification under local Topical anesthesia.

Materials and methods: In this double-blind randomized clinical trial, a total of 90 cataract surgery candidates undergoing phacoemulsification were selected and divided into three groups. The first group received 1 µg/kg dexmedetomidine over 10 minutes, followed by an infusion of dexmedetomidine at a rate of 0.5 µg/kg/h. The second group received 0.05 mg/kg midazolam, and the third group received 0.2 mg/kg slow IV etomidate. Hemodynamic parameters, sedation level, and adverse effects were recorded before anesthesia, during surgery, and during recovery.

Results: The results of this study showed that in the 10^th minute of surgery, the systolic blood pressure (SBP) in the etomidate group was significantly higher than the other groups P value = 0.029). The pulse rate (PR) in the etomidate group at the 15^th minute during surgery, 10^th, 20^th, and 30^th minute in the recovery period (mean 70.33 ± 10.34 bpm, 72.10 ± 10.18 bpm, 73.70 ± 10.18 bpm, and 75.03 ± 6.73 bpm, respectively) was significantly higher than the other two groups (P value < 0.05). No adverse effects such as dizziness, restlessness, vomiting, or nausea were observed in the midazolam group. However, decreased heart rate was significantly higher in the dexmedetomidine group (26.7%) compared to the etomidate (3.3%) and midazolam (6.7%) groups (P value = 0.021).

Conclusion: According to the results of this study, the sedation level achieved by dexmedetomidine, midazolam, and etomidate was similar. However, etomidate seemed to have a better effect on maintaining blood pressure and pulse rate compared to the other two drugs.