Randomised double-blind comparison of morphine vs. a morphine-alfentanil combination for patient-controlled analgesia.
In a randomised, double-blind study, we compared a combination of morphine and alfentanil with morphine alone for patient-controlled analgesia (PCA) after Caesarean section under spinal anaesthesia. After surgery, patients were randomly allocated to receive PCA with a bolus dose of either morphine 0.75 mg plus alfentanil 0.125 mg (Group MA, n = 40) or morphine 1.5 mg alone (Group M, n = 37) with a lockout interval of 8 min and no hourly dose limit. Clinical assessments were made in the first 24 h, after which patients completed a written questionnaire. There were no differences between groups in PCA usage or visual analogue scale pain scores measured at 2, 4, 6 and 24 h. There was a low incidence of side-effects in both groups. In the questionnaire, patients in Group MA scored higher compared with Group M when asked to grade speed of onset and effectiveness of analgesia after a PCA bolus; there were no differences in grading for duration of analgesia or overall patient satisfaction. Addition of alfentanil to morphine may have advantages for PCA.
Associate Professor, Department of Anaesthesia, The Chinese University of Hong Kong, China.
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Ngan Kee
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Khaw
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Wong
D000328:Adult; D015760:Alfentanil / Q000008:administration & dosage*; D016058:Analgesia, Patient-Controlled / Q000379:methods*; D000701:Analgesics, Opioid / Q000008:administration & dosage*; D004311:Double-Blind Method; D004338:Drug Combinations; D006801:Humans; D009020:Morphine / Q000008:administration & dosage*; D010147:Pain Measurement; D010149:Postoperative Pain / Q000517:prevention & control*
D000701:Analgesics, Opioid; D004338:Drug Combinations; D015760:Alfentanil; D009020:Morphine