Analgesic action of metoclopramide in prosthetic hip surgery

Prosthetic hip surgery was performed under subarachnoidal anaesthesia with bupivacaine 16-20 mg and morphine 0.2 mg. Preoperatively, metoclopramide 1 mg.kg-1 was given i.v., followed by an infusion of 1.5 mg.kg-1 over 9 h (n = 17). Control patients received corresponding volumes of solvent (n = 23. The design of the study was double blind. The characteristics of the spinal block (level of analgesia to pinprick and muscular block) and postoperative VAS pain scores were similar in both groups. During the 24 h following the start of the infusion, four patients receiving metoclopramide required i.v. opioids, compared to 15 in the control group (P < 0.05). The pain-free period was longer (P < 0.05) in the metoclopramide group. Arterial PCO2-levels were increased, reaching a maximum within 6 h of infusion, with no significant difference between the groups. The study suggests an analgesic action of metoclopramide.