Effect of dexmedetomidine for attenuation of propofol injection pain in electroconvulsive therapy: a randomized controlled study.

Purpose: Current analgesic strategies for propofol injection pain may cause adverse reactions during electroconvulsive therapy (ECT), such as shortening seizure duration. This study investigated whether dexmedetomidine could attenuate propofol injection pain in ECT.

Methods: Participants were randomly allocated to receive 0.2 μg/kg dexmedetomidine (Dex-0.2 group), 0.5 μg/kg dexmedetomidine (Dex-0.5 group) or saline (control group) prior to ECT. The composite pain scale and objective Surgical Pleth Index (SPI) were used to measure the intensity of injection pain, and the percentage of patients with pain score > 2 was the primary outcome.

Results: Of 137 patients recruited, 46 were assigned to each of the Dex-0.2 or Dex-0.5 groups, while 45 were in the control group. The percentage of pain score > 2 was reduced from 68.9% (31/45) in the control group to 34.8% (16/46) in the Dex-0.2 group (P < 0.001) and 15.2% (7/46) in the Dex-0.5 group (P < 0.001). The pain score and SPI at 5 s after propofol injection were greater in the control group than in the Dex-0.2 [pain scores 3 (2-4) vs. 1 (1-3), P < 0.001, SPI 76.6 ± 10.0 vs. 58.0 ± 11.0, P < 0.001] and Dex-0.5 groups [pain scores 3 (2-4) vs. 1 (0-1), P < 0.001, SPI 76.6 ± 10.0 vs. 51.2 ± 12.3, P < 0.001]. There were no significant differences in seizure duration between the three groups. No patients developed bradycardia and hypotension.

Conclusions: Pretreatment with dexmedetomidine was able to reduce the propofol injection pain in ECT without interfering with the seizure duration and causing adverse effects such as bradycardia and hypotension. In addition, close monitoring of hemodynamic variables and preparation of a treatment plan and drugs for bradycardia are essential.