Applications of Magnesium Sulphate in Anesthesia

Abstract

Magnesium is a co-factor in more than 325 enzyme systems in cells and is the second most abundant intracellular cation after K. It is important in numerous physiologic and homeostatic functions such as hormone-receptor binding, gating of Ca2+ channels, transmembrane flux of ions, regulation of adenylate cyclase, Calcium ions release, muscle contraction, cardiac excitability, neuronal activity, control of vasomotor tone and neurotransmitter release. Hypomagnesemia is an important but underdiagnosed electrolyte abnormality specially in critically ill and surgical patients, it has been associated to increased morbidity and mortality and increased hospital stay. Magnesium sulphate has been used in preeclampsia patients in order to prevent seizure. It is also used for the treatment of arrhythmia and asthma and as an anesthetic adjunct in patients undergoing surgery for pheochromocytoma. However, its potentiating effects on perioperative analgesia and muscle relaxation have drawn attention recently. These characteristics of magnesium (anesthetic- and analgesic-sparing effect) enable anesthesiologists to reduce the use of anesthetics during surgery and the use of analgesics after surgery. Magnesium sulfate has a high therapeutic index and cost-effectiveness. Considering these diverse characteristics useful for anesthesia, appropriate use of magnesium sulfate would improve surgical outcome and patients' satisfaction.