Sodium nitroprusside contains 40 percent cyanide by weight. Cyanide is released by the deterioration of sodium nitroprusside in aqueous solutions, especially when exposed to bright sunlight. The rate of rise of cyanide levels in patients on a nitroprusside infusion is proportional to the infusion rate and increases at infusion rates greater than 1 to 2 ^g/kg/min.6 The onset of poisoning occurs after several days of therapy, so the emergency physician will see this problem only if called to the intensive care unit to evaluate a deteriorating patient. Cyanide poisoning should be suspected in patients receiving nitroprusside infusions who develop mental state disturbances or unexplained metabolic acidosis. In patients in whom a Swan-Ganz catheter is used for monitoring, a narrow ( A-v) O2 difference, especially in the setting of an unchanged or declining cardiac output, suggests cyanide toxicity. 6
Was this article helpful?
The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.