Rocuronium Injection Pain is Attenuated by NaHCO3

Han, Dong Woo; Koo, Bon Nyeo; Hwang, Sae Il; Shin, Yang Sik; Kim, Ki Jun

Abstract

BACKGROUND: Rocuronium administration is associated with a severe burning pain during injection. However, the mechanistic cause of the pain has not been well established. The purpose of this study was to determine whether adjusting the pH of the rocuronium with NaHCO3 would ameliorate the pain.
METHODS
We examined mixtures using microscope after NaHCO3 was mixed with rocuronium to exam solubility. Sixty of 80 patients scheduled for elective gynecologic surgery were randomly allocated to one of three groups as follows: group 1 (rocuronium only, n = 20), group 2 (rocuronium 50 mg/5 ml mixed with 0.9% NaCl 3 ml, n = 20), group 3 (rocuronium 50 mg/5 ml mixed with NaHCO3 3 ml, n = 20). All patients received 0.6 mg/kg of rocuronium over 10 sec and were asked to assess pain using a visual analogue scale (VAS) followed by injection of propofol 1.5 mg/kg and fentanyl 100 mcg. The onset and duration of rocuronium were measured in three groups. Twitch responses to cumulative incremental doses of rocuronium were measured in another 20 patients, allocated to group A (rocuronium only, n = 10) or group B (rocuronium 50 mg/5 ml mixed with NaHCO3 3 ml, n = 10).
RESULTS
Over 24 hours, no precipitation or particles were found after mixing NaHCO3 with rocuronium. The VAS was significantly lower in group 3 (0.5+/-0.9) than in group 1 (5.4+/-3.2) or in group 2 (4.9+/-2.1) (P < 0.05). Eighteen of 20 patients in group 3 had no pain and only 2 had mild pain, but all patients in groups 1 and 2 had mild to severe pain. There were no differences in onset or duration between the three groups and in twitch responses between group A and B.
CONCLUSIONS
NaHCO3 mixed with rocuronium attenuates rocuronium injection pain, and there were no problems or complications.