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HelpTest ID CYAN Cyanide, Blood
Useful For
Monitoring possible exposure to cyanide
Establishing cause of death in cyanide exposure
Not useful for monitoring nitroprusside.
Method Name
Colorimetric
Reporting Name
Cyanide, BSpecimen Type
Whole Blood EDTAContainer/Tube: Lavender top (EDTA)
Specimen Volume: 3 mL
Specimen Minimum Volume
1.5 mL
Specimen Stability Information
| Specimen Type | Temperature | Time |
|---|---|---|
| Whole Blood EDTA | Ambient (preferred) | 14 days |
| Frozen | 14 days | |
| Refrigerated | 14 days |
Clinical Information
Cyanide (hydrocyanic acid, prussic acid) blocks cellular respiration by binding to and inactivating hemoglobin and enzymes such as cytochrome oxidase having prosthetic groups containing ferric iron (Fe+++). Cyanide is metabolized rapidly by the liver where it is converted to thiocyanate.
Therapy of hypertensive crisis with nitroprusside (Nipride) results in elevated cyanide blood concentrations, because the cyano function is transferred from nitroprusside to hemoglobin in the red cell.
Symptoms of cyanide poisoning include giddiness, hyperpnea, headaches, palpitation, cyanosis, and unconsciousness. Asphyxial convulsions may precede death; death normally ensues within a few minutes to 3 hours, depending upon the dose. As long as the heart continues to beat, there is a chance of saving the patient because effective antidotes are available; treatment with sodium nitrite and sodium thiosulfate can be effective.
Reference Values
Normal: <0.2 mcg/mL
Toxic concentration: ≥2.0 mcg/mL
Cautions
Concentrations as high as 8.0 mcg/mL without symptoms of cyanide toxicity are commonly associated with nitroprusside therapy; one should monitor thiocyanate to determine the potential for intoxication during nitroprusside therapy for hypertensive crisis.
Day(s) Performed
Monday, Wednesday, Friday; 5 p.m.
Report Available
Same day/1 dayPerforming Laboratory
Mayo Medical Laboratories in Rochester
Test Classification
This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.CPT Code Information
82600