Prevention of pain due to injection of propofol with IV administration of lidocaine 40 mg + metoclopramide 2.5, 5, or 10 mg or saline: a randomized, double-blind study in Japanese adult surgical patients.

BACKGROUND

Pain on injection is a recognized adverse event (AE) with propofol, an agent used to induce general anesthesia in surgical patients. Lidocame (LID) has been found efficacious in reducing pain on injection of propofol; however, this type of pain may not be completely eliminated with LID. Metoclopramide (MET) is a dopamine receptor agonist with antiemetic and prokinetic properties used for the treatment of nausea and facilitation of gastric emptying in patients with gastroparesis. MET also has local anesthetic properties similar to those of LID.

OBJECTIVE

The aim of this study was to examine the effects of LID administered with 3 different doses of MET or saline on pain on injection of propofol in Japanese adults undergoing elective surgery.

METHODS

This randomized, double-blind study was conducted at the Department of Anesthesiology, University of Tsukuba Institute of Clinical Medicine, Tsukuba, Japan. Japanese patients aged 20 to 67 years who were scheduled to undergo elective surgery were eligible for participation. Patients were randomized to receive N administration of LID 40 mg + MET 2.5, 5, or 10 mg or saline. A rubber tourniquet was used to perform 1 minute of venous occlusion before administration of the study and control drugs, and then 25% of the total calculated dose of propofol (2 mg/kg) was injected into the dorsal vein of the hand through a 20-G N cannula at a rate of 1 mL/s. During a 10-second pause before the induction of anesthesia, patients were questioned by a blinded investigator about the pain intensity on injection. Pain intensity was assessed through the use of a 4-point verbal rating scale, with scores ranging from 0 (no pain) to 3 (severe pain). Incidence and intensity of pain (as assessed by mean pain scores) were determined in each of the 4 study groups. Extrapyramidal reactions and injection-site AEs, including pain, edema, wheals, and inflammation occurring up to 24 hours after surgery were recorded by a blinded investigator.

RESULTS

The study enrolled 240 patients (126 men, 114 women; mean [SD] age, 43 [13] years [range, 20-67 years]; mean [SD] height, 160 [8] cm [133-181 cm]; mean [SD] body weight, 57 [10] kg [range, 33-85 kg]). There were 60 patients randomized to each of the 4 study groups, which were comparable in distribution of demographic characteristics. Incidence of propofol-induced pain was significantly lower, but the intensity of pain was not less, in the groups that received LID/MET 40/5 or 40/10 (both, 5%) compared with those who received LID/MET 40/2.5 or LID/saline (18% and 20%, respectively) (all, P < 0.05). There were no reports of injection-site AEs or extrapyramidal reactions after injection of the control or study drugs in any of the study groups.

CONCLUSION

Among these 240 Japanese patients undergoing elective surgery, N administration of LID/MET 40/5 or 40/10 was associated with lower incidence, but not lower mean pain intensity scores, of pain on injection of propofol than LID/MET 40/2.5 or LID/saline before induction of anesthesia.