Prevention of pain with the injection of microemulsion propofol: a comparison of a combination of lidocaine and ketamine with lidocaine or ketamine alone.
BACKGROUND
Aquafol, a microemulsion propofol, causes more severe and frequent pain on injection than propofol. The purpose of this study was to compare a combination of lidocaine and ketamine on aquafol-induced pain with lidocaine or ketamine alone during the induction of anesthesia.


METHODS
In this prospective, randomized, double-blinded study, 130 healthy patients who were undergoing elective surgery under general anesthesia were enrolled. The patients received IV lidocaine 40 mg plus ketamine 25 mg (Group LK, n = 43), lidocaine 40 mg (Group L, n = 42), or ketamine 25 mg (Group K, n = 45) with a rubber tourniquet on the forearm 1 min before the injection of microemulsion propofol. The pain score was assessed by a 4-point verbal rating scale (VRS) at 10 seconds after injection of microemulsion propofol 30 mg and during the injection of the remaining total dose.


RESULTS
The incidence and severity of pain was significantly lower in Group LK than Group L or Group K at 10 seconds after the injection of microemulsion propofol 30 mg (P < 0.05). And the incidence and severity of pain was significantly lower in Group LK and Group K than Group L during the injection of the remaining total dose (P < 0.05).


CONCLUSIONS
Pretreatment with IV lidocaine 40 mg plus ketamine 25 mg with a rubber tourniquet on the forearm 1 min before the injection of microemulsion propofol is more effective than lidocaine 40 mg or ketamine 25 mg alone in preventing pain from the injection of microemulsion propofol.
Department of Anesthesiology and Pain Medicine, Soonchunhyang University Hospital, College of Medicine, Soonchunhyang University, Seoul, Korea.
Insung
I
Hwang
Jung Il
JI
Noh
Soon Im
SI
Kim
Mun-Gyu
MG
Kim
Sun-Young
SY
Park
Sang Ho
SH
Kim
Si Young
SY
Ok