Vesey C J, Stringer M, Cole P V
Anaesthetics Laboratory, St Bartholomew's Hospital, West Smithfield, London.
Br J Anaesth. 1990 Jun;64(6):696-703. doi: 10.1093/bja/64.6.696.
The apparent intravascular decomposition of nitroprusside (SNP) has been attributed to photolysis and artefactual generation of cyanide (HCN) during assay, leading some workers to believe that large doses of SNP may be infused safely if light is excluded. However, we have shown that HCN is not produced from SNP during analysis. Significant amounts of HCN were formed only when SNP was first incubated with blood. The yield of HCN was a function of the temperature, pH and time of incubation. The time for release of 50% of the HCN from SNP 5 mumol litre-1 at 37 degrees C in blood was 26.6 min with greater than 90% yield in 2 h, and in plasma the optimum pH was about 7.5. A u.v. method for measuring SNP suggests that, at clinically appropriate blood concentrations, SNP is confined to plasma.
硝普钠（SNP）在血管内的明显分解被认为是由于光解作用以及在检测过程中人为生成氰化物（HCN），这使得一些研究人员认为，如果排除光照，大剂量输注SNP可能是安全的。然而，我们已经表明，在分析过程中SNP不会产生HCN。只有当SNP首先与血液孵育时才会形成大量的HCN。HCN的生成量是温度、pH值和孵育时间的函数。在37℃下，5 μmol/L的SNP在血液中释放50% HCN的时间为26.6分钟，2小时内产率超过90%，在血浆中最佳pH值约为7.5。一种测量SNP的紫外方法表明，在临床合适的血液浓度下，SNP局限于血浆中。
