SummaryThe requirements for analgesia after upper abdominal surgery were evaluated in 100 patients who received morphine by way of a patient-controlled analgesia system. Hourly and cumulative 24-hour No correlation was found between morphine consumption and patient weight. The pattern of hourly morphine consumption appeared to follow a diurnal rhythm, with peak times of demand at 0900 and 2000 hours. The variations in requirements for analgesia among patients and with time of day should be taken into account when a regimen for postoperative analgesia is prescribed. Key wordsAnalgesia; postoperative, patient-controlled analgesia.Effective postoperative analgesia is of paramount importance, particularly after major abdominal surgery. Several studies have reported a wide range of individual requirements for, and responses to, analgesic However most patients still receive intramuscular o p i o i d~,~ prescribed at fixed time intervals, for pain relief in the early postoperative period. The bolus dose is determined usually by patient variables such as age, gender and weight, which are considered to influence the pharmacokinetic profile of analgesic drugs, although previous studies have shown no correlation between weight, height or body surface area and pain relief after a single dose of morphine or pentazocine. A significant inverse correlation between age and pain relief has been demon~trated.~ Patient-controlled analgesia (PCA) is a relatively new concept in the management of postoperative pain.' It provides a unique opportunity to examine the requirements for analgesia and to reassess the factors which are thought to influence them. We have studied the morphine requirements of 100 patients who received morphine delivered by a PCA system as the sole method of analgesia in the first 24 hours after upper abdominal surgery, and analysed these requirements with regard to age, weight, gender and time of day. MethodsOne hundred patients aged 18-75 years, who had undergone upper abdominal surgery were studied. Patients with cardiac, hepatic, or renal dysfunction were excluded, as were those patients who received regular analgesic drugs pre-operatively. All patients had given informed consent for the study.The system comprised an Imed 929 computer-controllable infusion pump connected to an Apple IIe microcomputer.8 The PCA system was connected to the patient's intravenous infusion by way of a nonreturn valve, and was programmed to deliver an incremental dose of morphine 0.02 mg/kg, with a lock-out interval of 2 minutes. Maximum dosage was 0.4 mg/kg in one hour. Start time and the time of each bolus dose were recorded and stored on disk.

SummaryA randomised, double-blind study of

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The efficacy of a single dose of intramuscular ketorolac 10 mg or 90 mg was compared with pethidine 100 mg in a randomized double-blind study in 121 patients reporting at least moderate pain due to renal colic. Pain was assessed before drug administration, and then at 1 hour and 12 hours after the dose. Sedation was also assessed at these times, and additionally at the 12 hour assessment the time of the next analgesic dose was recorded. At 1 hour after dosing, pain scores had decreased in all groups; the largest decrease was seen in the ketorolac 90 mg group. The difference in the decrease was significant between the two ketorolac groups, but the differences between ketorolac and pethidine were not significant. Fewer patients in the ketorolac 90 mg group (17%) required a further dose of analgesic within 10 hours than in either the ketorolac 10 mg group (39%) or the pethidine 100 mg group (47%). The difference between ketorolac 90 mg and pethidine 100 mg was statistically significant. At both assessment times the proportion of patients with no sedation was higher in the two ketorolac groups than in the pethidine group. The overall incidence of adverse events was low with all drugs, notably so for the occurrence of vomiting after ketorolac. The results of the study show that intramuscular ketorolac is efficacious in the treatment of renal colic.

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