Thank you for the opportunity to be able to be involved in a review and education of the toxicity and side effects of nitroprusside for the CVICU team.
A brief overview of Nitroprusside, it is a hypotensive agent that acts on venous and arterial smooth muscle causing peripheral dilation. Because it is more active on veins than arteries it allows for a decrease in venous return leading to a decrease in left ventricular end diastolic pressure and preload. It has a quick onset of action of less than 2 minutes and a duration of up to 10 minutes. The half-life of nitroprusside is approximately 2 minutes. As it is metabolized, nitroprusside will combine with hemoglobin to produce cyanmethemoglobin and 4 cyanide anions. Cyanmethemoglobin …show more content…
Patients who undergo cardiac surgery may also be at an increased risk for cyanide toxicity. Signs and symptoms of cyanide toxicity may include: hyperoxemia, metabolic acidosis, CNS dysfunction (confusion) and possibly death. Patients at higher risk for developing cyanide toxicity from nitroprusside infusions are those with hypoalbuminemia, cardiopulmonary bypass procedures, renal impairment, or those being administered a moderate to high dose. Thiocynate toxicity may manifest itself as abdominal pain, vomiting, weakness, disorientation and coma in severe cases. Other side effects of nitroprusside include: severe hypotension, bradycardia, palpitations, dizziness, headache, increased intracranial pressure, diaphoresis, abdominal pain, nausea, and methemoglobinemia.
Cyanide poisoning can be treated with sodium nitrite and sodium thiosulfate. The recommended dose of sodium nitrite is 300 mg (10 mL) of a 3% solution given IV over 2-4 minutes followed by 50 mL (12.5g) of a 25% sodium thiosulfate solution. If signs of toxicity recur the same treatment may be repeated at half the doses 2 hours after first treatment