Ephedrine reduces the pain from propofol injection

One hundred seventy-six patients (ASA physical status I or II) presenting for elective surgery were randomly allocated into six study groups to compare the incidence of propofol-induced pain after pretreatment with different doses of ephedrine as compared with lidocaine. Patients in Group P (n = 30) received saline placebo; patients in Group L (n = 30) received 2% lidocaine 40 mg; patients received ephedrine 30 microg/kg (Group E30, n = 28), 70 microg/kg (Group E70, n = 30), 110 microg/kg (Group E110, n = 30), and 150 microg/kg (Group E150, n = 28), respectively, followed 30 s later by propofol 2.5 mg/kg. A blinded anesthesiologist asked the patient to evaluate the pain score (verbal rating scale and face pain scale). The incidence and intensity of pain was less in the lidocaine and ephedrine groups than in the placebo group (P < 0.01). Before tracheal intubation, the arterial blood pressure was decreased in the P and L groups, and after intubation, hemodynamics were increased in the E110 and E150 groups, respectively (P < 0.05). We concluded that pretreatment with a small dose of ephedrine (30 and 70 microg/kg) reduced the incidence and intensity of propofol-induced pain with a lesser decrease in arterial blood pressure than from propofol alone in lidocaine pretreatment.

Propofol is a widely used IV anesthetic for the induction of anesthesia, but it often causes local pain when administered into peripheral veins. A small dose of ephedrine reduces the incidence and intensity of the pain without significant adverse hemodynamic effects during induction.