Priming with different doses of metoclopramide preceded by tourniquet alleviates propofol induced pain: A comparative study with lidocaine

Abstract

Objectives: To evaluate the outcome of priming by varying-doses of metoclopramide on propofol injection pain in comparison to lidocaine as a standard control. Methods and materials: 320 patients were randomly allocated into 4 equal groups: Group C received 50 mg lidocaine and Groups M1-3 received metoclopramide 2.5, 5 and 10 mg, respectively. An elastic tourniquet was applied to the mid of left arm, the priming solution was injected over 10 s and 1-min later, tourniquet was removed and one fourth of the total calculated dose of Propofol was injected over 30 s and pain assessment was made, during initial and at end of injection of Propofol trial dose, using the 4-point verbal rating scale: no, mild, moderate or severe pain. Then, the reminder of the full calculated induction dose of Propofol was completed. Results: Lidocaine and metoclopramide mostly relieved pain of initiation of Propofol injection 174 patients (54.4%) had no pain 94 patients (29.4%) had mild pain and only 68 patients (21.25%) had moderate pain, while no patient had severe injection pain. At the end of injection of the total trial dose, 40% had no pain totally, 31.3% had mild pain, 19.3% had moderate pain and 9.4% had severe pain. Lidocaine provided significantly better analgesia compared to metoclopramide (2.5 mg), while the difference was non-significantly better compared to metoclopramide, 5 and 10 mg. Metoclopramide provided dose-dependent stepwise pain relieve peaking with 10 mg dose that showed significant superiority compared to 2.5 mg dose, but non-significantly compared to 5 mg dose. Moreover, the effect of 10 mg priming dose extended till completion of injection of the trial dose with significant difference Compared to the other two doses of metoclopramide. Conclusion: venous priming with metoclopramide 10 mg with mid-arm tourniquet applied for one minute is effective modality for alleviation of Propofol injection pain else Patients received Lidocaine showed significantly better analgesia compared to those received 2.5 mg metoclopramide. Keywords: Propofol injection pain, Metoclopramide, Lidocaine, Tourniquet, Venous priming