To Evaluate the Effectiveness of Magnesium Sulphate as an Agent to induce Hypotensive Anaesthesia in Lumbar Spine Surgery. A Prospective Randomized, Placebo-Control Study

Introduction: This randomized placebo controlled study wasdesigned to evaluate the effectiveness of magnesium sulphateas an agent to induce hypotensive anaesthesia in lumbar spinesurgery.Material and Methods: The study included 100 patients ofboth sexes who were equally distributed in two groups, theGroup Mg(Magnesium sulphate group) and Group C (controlgroup). The Magnesium group received magnesium sulphate40mg/kg administered as a slow IV bolus over a period of 10minutes before induction and 15mg/kg/hr by continuous IVinfusion during surgery. The same volume of isotonic salinewas administered to the control group. Surgical time, heartrate and mean arterial blood pressure was measured.Results: In the magnesium group there was reduction insurgical time (103.54 mins vs 117.34 mins), although theanaesthestic time was 9 minutes longer in the Magnesiumgroup denoting a longer emergence time. The mean arterialpressure and heart rate were significantly reduced inMagnesium group(p<0.005). Postoperative shivering was alsoless in Magnesium group.Conclusion: Magnesium infusion resulted in a steady andsmooth reduction in mean blood pressure and reduced heartrate, with no episodes of severe hypotension. Furthermoremagnesium causes reduction in duration of surgical time andpostoperative shivering

Carotid body tumor resection and hypotensive anaesthesia during 1985-1991.

We retrospectively analysed the administration of anaesthesia for carotid body tumor resection in Siriraj Hospital during 1985-1991. The tumors were excised from seven patients under general hypotensive anaesthesia. Such slow-growing large tumors frequently encircle the internal and external carotid arteries, which increases the risk of massive blood loss and damage to major cranial nerves. Thus, carotid arteriography for diagnosis and demonstration of collateral circulation and cardiovascular monitoring during resection was indispensable. All tumors were completive death. Following surgery, one patient developed transient weakness of the upper extremity which lasted one week. Cranial nerve palsy (CN IX, X) occurred in one patient who recovered in three months.