Antiemetic efficacy of metoclopramide when included in a patient‐controlled analgesia infusion

A double-blind, randomised, controlled trial was performed to assess the antiemetic efficacy of metoclopramide when included in a morphine patient-controlled analgesia regimen. Fifty ASA grade 1 or 2 patients scheduled for elective intermediate or major gynaecological surgery were allocated into one of two groups. All patients received a standardised anaesthetic and metoclopramide 5 mg was given intravenously 10 min before the end of the procedure. Group 1 received a patient-controlled analgesia regimen using morphine 1 mg.ml-1 solution. Group 2 received a patient-controlled analgesia regimen using morphine 1mg.ml-1 with metoclopramide 0.5 mg.ml-1 solution. Postoperative antiemetic treatment was with metoclopramide 10 mg intramuscularly or cyclizine 50 mg intramuscularly if this was ineffective. Pain scores, sedation scores, and morphine requirement were not significantly different between the groups. There was no difference in nausea scores between the groups, but more patients suffered moderate or severe nausea in group 1 (10 patients) than group 2 (three patients, p < 0.026). We conclude that metoclopramide, when included in a patient-controlled analgesia regimen, reduces the incidence of moderate to severe nausea, but not the overall incidence of nausea.