LETTER TO THE EDITOR

Magnesium sulphate forphaeochromocytoma crisisClarke et al. presented a case of phaeochromocytomacrisis manifesting as catecholamine cardiomyopathy ina recent issue of the journal.1 I would like to suggest thatmagnesium sulphate should be considered as a treat-ment option in the ED when phaeochromocytoma isconsidered as a possible cause of severe hypertension orcardiomyopathy.

Magnesium reduces catecholamine release, is ahighly effective alpha-adrenergic antagonist and anti-arrhythmic in the setting of large-dose epinephrine infu-sions, and is predominantly an arteriolar dilator withminimal effects on pulmonary capillary wedge pressureand venous return.2,3 It is readily available and simple touse. There is extensive literature on the efficacy of mag-nesium sulphate in the management of hypertensionand arrhythmias during surgical removal of phaeochro-mocytoma, often without preceding alpha-blockade.Several case reports describe its successful use in indi-viduals with phaeochromocytoma crisis, including cat-echolamine cardiomyopathy, where phentolamine andnitroprusside were unsuccessful.4,5

In conclusion, emergency physicians should be awareof magnesium sulphate as a treatment option when aphaeochromocytoma crisis is considered.

References

1. Clarke B, Ryan G, Fraser J, Francis L. Uncommon cause ofcardiac arrest in the emergency department. Emerg. Med.Australas 2007; 19: 169–72.

2. James MF, Beer RE, Esser JD. Intravenous magnesium sulphateinhibits catecholamine release associated with tracheal intuba-tion. Anesth. Analg. 1989; 68: 772–6.

3. James MFM, Cork RC, Harlen GN, White JF. Interactions ofadrenaline and magnesium on the cardiovascular system of thebaboon. Magnesium 1988; 7: 37–43.

4. James MF, Cronje L. Pheochromocytoma crisis: the use of mag-nesium sulphate. Anesth. Analg. 2004; 99: 680–6.

5. Bullough A, Karadia S, Watters M. Pheochromocytoma: anunusual cause of hypertension in pregnancy. Anaesthesia 2001;56: 43–6.

Adam Morton

Mater Hospital, South Brisbane, Queensland, Australia

doi: 10.1111/j.1742-6723.2007.01007.xEmergency Medicine Australasia (2007) 19, 482

© 2007 The AuthorJournal compilation © 2007 Australasian College for Emergency Medicine and Australasian Society for Emergency Medicine