Fahmy N R
Anesthesiology. 1981 Apr;54(4):305-9. doi: 10.1097/00000542-198104000-00009.
In view of evidence suggesting possible participation of cobalamin in cyanide metabolism, the effects of sodium nitroprusside (SNP) infusion on blood cyanide and plasma thiocyanate levels and serum vitamin B12 levels were examined in ten patients undergoing major orthopedic procedures. Whole blood cyanide concentrations increased significantly (P less than 0.001) from 3.6 +/- 1.1 to 65.7 +/- 16.2 micrograms/dl, and total serum B12 values decreased significantly (P less than 0.005) from 482 +/- 56 to 267 +/- 42 pg/ml, three hours after SNP therapy. Plasma thiocyanate did not change. Cyanide released from SNP converts hydroxocobalamin to cyanocobalamin, which is readily excreted in urine. These variables were not changed in six patients (control) who received trimethaphan. In vitro experiments revealed that none of the serum factor(s) nor nitroprusside interfered with the assay of B12. Hydroxocobalamin may be an appropriate adjunct during SNP therapy.
鉴于有证据表明钴胺素可能参与氰化物代谢，我们对10例接受大型骨科手术的患者进行了研究，观察硝普钠（SNP）输注对血氰化物、血浆硫氰酸盐水平及血清维生素B12水平的影响。SNP治疗3小时后，全血氰化物浓度从3.6±1.1微克/分升显著增加（P<0.001）至65.7±16.2微克/分升，血清总B12值从482±56皮克/毫升显著降低（P<0.005）至267±42皮克/毫升。血浆硫氰酸盐未发生变化。SNP释放的氰化物将羟钴胺转化为氰钴胺，后者可随尿液轻易排出。接受三甲硫吩的6例患者（对照组）的这些变量未发生变化。体外实验表明，血清因子和硝普钠均不干扰B12的测定。羟钴胺可能是SNP治疗期间的一种合适辅助药物。
