Magnesium—Essentials for Anesthesiologists

Abstract

Magnesium plays a fundamental role in many cellular functions, and thus there is increasing interest in its role in clinical medicine. Although numerous experimental studies indicate positive effects of magnesium in a variety of disease states, large clinical trials often give conflicting results. However, there is clear evidence for magnesium to benefit patients with eclampsia or torsades de pointes arrhythmias. In addition, magnesium seems to have antinociceptive and anesthetic as well as neuroprotective effects, yet well-designed large clinical trials are required to determine its actual efficacy in pain management or in the state of stroke or subarachnoid hemorrhage. The current review aims to provide an overview of current knowledge and available evidence with respect to physiologic aspects of magnesium and proposed indications and recommendations for its use in the clinical setting.

Refractory status epilepticus after inadvertent intrathecal injection of tranexamic acid treated by magnesium sulfate

“…15 Among its many actions, it has a central nervous system depressant effect as an N-nitrosodimethylamine (NMDA) receptor antagonist and an inhibitor of catecholamine release. Both of these pathways could explain how magnesium benefited our patient.…”

“…There is evidence that seizures are mediated through NMDA receptors, so an antagonist could inhibit seizure activity. 15,16 Magnesium is administered for the prevention and treatment of eclamptic seizures. 16 Mechanisms thought to be International Journal of Obstetric Anesthesia 3 involved in the treatment of eclampsia include vasodilation, blood brain barrier protection to decrease cerebral edema and central anticonvulsant effects.…”

“…Magnesium produces vasodilatation through calcium antagonism in vascular smooth muscle. 15 Thus, if cerebral vasoconstriction is involved in producing global ischemia, magnesium could promote blood flow. Magnesium has also been applied for the treatment of cardiac arrhythmias.…”

“…Although not used routinely in Advanced Cardiac Life Support algorithms, it has been used for malignant cardiac arrhythmias, such as torsades de pointes. 15 Studies have shown that magnesium slows electrical activity in the SA node, prolongs AV conduction, and increases the refractory period of the AV node. 15 Several patients experienced cardiac arrhythmias after accidental spinal tranexamic acid administration which were refractory to defibrillation.…”

“…15 Studies have shown that magnesium slows electrical activity in the SA node, prolongs AV conduction, and increases the refractory period of the AV node. 15 Several patients experienced cardiac arrhythmias after accidental spinal tranexamic acid administration which were refractory to defibrillation. 6,9 Magnesium sulfate might have been useful in stabilizing the cardiac arrhythmias in these patients.…”