[Does intravenous administration of magnesium have an effect on postoperative analgesia?]

The study involved 67 patients operated for malignant tumours of stomach and of the colon. The patients have been divided into 3 groups: the NORMO group--20 patients in whom the serum magnesium level remained normal during the whole period studied; the HYPO group--22 patients who developed hypomagnesaemia in the postoperative course; the MAG i.v. group--25 patients who on the day of surgery and on 4 days following surgery, received intravenously daily doses of 2.5 ml of 20% MgSO4 per each 500 ml of transfused fluids. In all patients, the basic analgesic used was morphine, administered intramusculary or extraduraly. In the intervals between the doses of morphine, patients received intravenous doses of noramidopirine. In all three groups, the daily amounts of morphine and noramidopirine received by patients was the same. The intravenous administration of daily doses of 8 to 14 mmol magnesium in the postoperative period does not affect the amount of analgesics given to patients.