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CASE 16

A 68-year-old female in a hypertensive crisis is being treated in the intensive

care unit (ICU) with intravenous nitroprusside for 48 hours. The patient’s

blood pressure was brought back down to normal levels; however, she was

complaining of a burning sensation in her throat and mouth followed by nau-

sea and vomiting, diaphoresis, agitation, and dyspnea. The nurse noticed a

sweet almond smell in her breath. An arterial blood gas revealed a significant

metabolic acidosis. A serum test suggests a metabolite of nitroprusside, thio-

cyanate, is at toxic levels.

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What is the likely cause of her symptoms?

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What is the biochemical mechanism of this problem?

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What is the treatment for this condition?