Stridor: a rare complication of magnesium sulfate therapy in a pregnant patient

Adel Ganaw, Nissar Shaikh, Tawfiq Abu-Aisha, Raphael Samuel, Firdous Ummunnisa


Magnesium sulfate is frequently used in severe preeclampsia and eclampsia for the prevention and reoccurrence of seizure activity. Their adverse effects of magnesium sulfate are minor but it cause respiratory depression and tetany. We report a case of stridor due to laryngospasm as result of hypocalcemia in a pregnant patient on magnesium sulfate therapy.A 30 year old gravida5 para 4 had severe preeclampsia started on magnesium sulfate therapy and to control her hypertension she was on labetalol and nifidipine. One hour after the lower segment cesarean section, she developed severe laryngospasm and stridor, no upper airway secretion but found to have hypocalcemia. She responded to immediate intravenous calcium chloride with dramatic clinical improvement. Patients on magnesium sulfate can have life threatening hypocalcemia and stridor. The calcium channel blockers may augment the hypocalcaemic effect of magnesium sulfate.


Calcium channel blockers, Eclampsia, Hypocalcemia, Laryngospasm, Magnesium sulfate, Preeclampsia and stridor

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Steegers EA, Von Dadelszen P, Duvekot JJ, Pinjneborg R. Preeclampsia. Lancet. 2010;376:631-44.

Smith JM, Lowe RF, Fullerton J, Currie SM, Harris L, Kantor EF. An integrative review of the side effects related to the use of magnesium sulfate for preeclampsia and eclampsia management. BMC Pregnancy Childbirth. 2013;13:34.

Eisenbud E, LoBue CC, Hypocalcemia after therapeutic use of magnesium sulfate. Arch Intern Med. 1976;136:688-91.

Stephine L. Koontz, Steven A. Friedman, Martin L. Schwartz, Symptomatic hypocalcemia after tocolytic therapy with magnesium sulfate and nifedipine. Am J Obstet Gynecol. 2004;190:1773-6.

G. Edward Morgan Jr, Maged S. Mikhail, Michael J. Murry. Abnormalities in calcium balance. In: G. Edward Morgan Jr, Maged S. Mikhail, Michael J. Murry, eds. Clinical Anesthesiology. 4th ed. New York: McGraw-Hill Medical; 2006: 685.