ABSTRACT
PURPOSE: This in vitro study was performed to determine whether changes in hemoglobin (Hb) concentration and temperature influenced the amount of cyanide (CN-) released from sodium nitroprusside (SNP). METHODS: Canine whole blood with a Hb concentration of 8.5 to 18.9 g·dl (5.3 to 18.9 mM) was equilibrated with SNP at either 37°C or 25°C, and CN- levels in plasma and red blood cells (RBC) were measured using the microdiffusion method. RESULTS: Changes in Hb concentration and temperature did not have any statistically significant effect on the CN- released from SNP in plasma. On the other hand, CN- levels in RBC decreased with increasing Hb concentrations. CN- levels in RBC were significantly lower at 25°C than at 37°C. CONCLUSION: Though the Hb concentration and temperature changed the amount of CN- released from SNP in RBC, the change observed was not clinically significant.
