No influence of dexmedetomidine on mechanical pain threshold in gynecological patients before induction of anesthesia

Abstract

Objective To observe the influence of dexmedetomidine on pressure pain threshold in gynecological patients before induction of anesthesia. Methods This study was a double-blind test. Sixty patients were randomly divided into two groups, group D: dexmedetomidine with a dosage of 0.7 μg/kg (0.35 ml/kg) was diluted to 2 μg/kg, and administered within 10 minutes; group N: 0.35 ml/kg of normal saline was injected within 10 minutes. The results of pressure pain threshold (0.1 cm2 probe and 0.01 cm2 probe) , pressure pain tolerance threshold (0.1 cm2 probe) , Narcotrend index (NTI) , modified OAA/S score, and vital signs include HR, MAP and SpO2 were recorded. Results After dexmedetomidine was injected, there were no statistical changes of mechanical pain test, and the similar results in group N was observed. NTI in group D was less than that in group N (76.87±27.21 vs 98.37±1.22, P<0.05) , modified OAA/S score in group D was less than that in group N (3.93±0.94 vs 5.00±0.00, P<0.00) . HR in group D decreased markedly compared with that in group N (64±8 vs 81±14, P<0.05) . Conclusion Dexmedetomidine does not affect mechanical pain threshold in gynecological patients with the dosage of 0.7 μg/kg before induction of anesthesia. Key words: Dexmedetomidine; Pain sensitivity; Mechanical pain threshold