Tehran University Medical Journal

Background: Pain associated with IV injection of propofol is seen in 28 to 90% of patients. A number of techniques have been tried to minimize propofol-induced pain, with variable results. We compared the efficacy of pretreatment with ephedrine and lidocaine for the prevention of propofol-induced pain.

Methods: One hundred and twenty adult patients, ASA physical status I-II, undergoing elective surgery were randomly assigned into six groups (20 each). Normal saline group received normal saline, lidocaine group received lidocaine 2% (40 mg), and ephedrine (E 30) group received 30 µg/kg ephedrine, ephedrine (E 70) group received 70 µg/kg ephedrine, ephedrine (E 100) group received 100 µg/kg ephedrine, ephedrine (E 150) group received 150 µg/kg ephedrine. All pretreatment drugs were made in two mL. Pain was assessed by a 100-point scale of visual analogue (VAS) (0= no pain, 100= the most severe pain) and (VRS) verbal rating scale at the time of propofol injection. Noninvasive mean arterial blood pressure (MAP) and HR were recorded before induction, just before intubation, and 1, 2, and 3 min after intubation, respectively.

Results: The mean of pain scorel during propofol injection was significantly more in Normal Saline group compared to lidocaine and ephedrine (E30, E70, E100, E150) groups but there was no significant difference between lidocaine and ephedrine (E30, E70, E100, E150) groups (80.9vs 59.6 and 56.2, 51.05, 52.8, 57.45) Kruskal- wallis P=0.009. The incidence of pain was also significantly more in Normal Saline group compared to lidocaine group and ephedrine's groups but there was no significant difference between lidocaine and different dose levels of ephedrine. A small dose of ephedrine (30 and 70 µg/kg) could prevent propofol induced pain before intubation and did not produce significant hemodynamic changes compared with the other groups after intubation.

Conclusions: Pretreatment with ephedrine (specially low dose) effectively attenuated pain intensity, and frequency with propofol injection without undesired complications.