honkpilleddoomer

honkpilleddoomer

The living envies the dead.
Feb 23, 2023
73
Sodium nitrite is commonly used to preserve meats, color stuff, and kill microbes. It can be used used to treat cyanide toxicity, but it can also cause harm when not indicated or overdosed
Sodium nitrite poisoning is most commonly reported as accidental, but has been reported as suicide method (see NYTimes article)
Patients with sodium nitrite poisoning present with cyanosis, hypoxia, AMS, dysrhythmias and can quickly proceed to cardiac arrest
Sodium nitrite converts the hemoglobin in your blood to methemoglobin and can therefore result in methemoglobinemia (https://www.sciencedirect.com/topic...)(https://www.youtube.com/watch?v=ihr5RNzKu6Q)
If you don't recall, normal hemoglobin carries oxygen through your body and it's generally good if it works well. Methemoglobin is a modified form of hemoglobin that EDIT: binds oxygen too well and therefore doesn't release it to tissues when necessary that doesn't carry oxygen well. If you have too much methemoglobin, your tissues don't get enough oxygen.
Sodium nitrite also probably has the added effect of vasodilation (because of the breakdown to NO - see the mechanism for nitroglycerine) resulting in pressure drops.
All and all this results in the 1-2 punch dysfunctional oxygen transport molecules and poor perfusion leading to general badness.
S/Sx of methemogloblinemia may include cyanosis that doesn't resolve with supplemental oxygen, brownish blood with venipuncture, and falsely low SpO2 readings.
Pulse oximetry will not be very useful for these patients.
If you have a expanded noninvasive pulse oximeter (https://www.masimo.com/products/continuous/rad57/) you may be able to detect increased levels of methemoglobin.
In both case-studies of EMS-treated sodium nitrite poisoning patients reported, cardiac arrest occurred in the presence of EMS, but this may not always be the case.
Field treatment for these patients includes airway management, vascular access, contacting poison control (1-800-222-1222) for guidance, and BLS/ACLS resuscitation as indicated
ER treatment includes methylene blue (standard dose 1-2mg/kg 1% solution IV over 5 minutes) which converts the methemoglobin back to normal hemoglobin. Treatment may also include other interventions like blood transfusion, hyperbaric oxygen, and ECMO; however none of these these interventions are well studied in patients already in cardiac arrest.

 
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