TY - JOUR
T1 - Prevention of fetal and maternal cyanide toxicity from nitroprusside with coinfusion of sodium thiosulfate in gravid ewes
AU - Curry, Steven C.
AU - Carlton, Michael W.
AU - Raschke, Robert A.
PY - 1997
Y1 - 1997
N2 - Coadministration of sodium thiosulfate with sodium nitroprusside (SNP) to children and adults prevents increases in cyanide concentrations during anesthesia or long-term SNP infusions. We wondered whether maternally administered sodium thiosulfate would prevent increases in fetal red cell cyanide concentrations in gravid ewes receiving SNP intrusions. Under anesthesia, the fetal head was delivered through a lateral hysterotomy for catheterization of the jugular vein; the fetus was left in utero. Six control ewes near term received SNP at 25 μg · kg-1 · min for 4 h. Norepinephrine was used to maintain maternal mean arterial pressure at 80% baseline values. Six experimental ewes received the same treatment except that sodium thiosulfate was infused with SNP (1 g sodium thiosulfate per 100 mg SNP). Serial red cell cyanide concentrations in ewes and fetuses were followed. One control fetal death resulted from abruptio placenta, and this ewe and fetus were excluded from analysis. An additional control ewe and fetus died from apparent cyanide poisoning late during the course of the experiment. While control ewes and fetuses suffered progressive increases in red cell cyanide concentrations into the toxic range, experimental ewes and fetuses never developed toxic red cell cyanide levels (ewes P < .003, fetuses P < .004). These data, if applicable to humans, suggest that coadministration of sodium thiosulfate with SNP to pregnant women at doses currently in use for nonpregnant patients will prevent fetal, as well as maternal, cyanide toxicity.
AB - Coadministration of sodium thiosulfate with sodium nitroprusside (SNP) to children and adults prevents increases in cyanide concentrations during anesthesia or long-term SNP infusions. We wondered whether maternally administered sodium thiosulfate would prevent increases in fetal red cell cyanide concentrations in gravid ewes receiving SNP intrusions. Under anesthesia, the fetal head was delivered through a lateral hysterotomy for catheterization of the jugular vein; the fetus was left in utero. Six control ewes near term received SNP at 25 μg · kg-1 · min for 4 h. Norepinephrine was used to maintain maternal mean arterial pressure at 80% baseline values. Six experimental ewes received the same treatment except that sodium thiosulfate was infused with SNP (1 g sodium thiosulfate per 100 mg SNP). Serial red cell cyanide concentrations in ewes and fetuses were followed. One control fetal death resulted from abruptio placenta, and this ewe and fetus were excluded from analysis. An additional control ewe and fetus died from apparent cyanide poisoning late during the course of the experiment. While control ewes and fetuses suffered progressive increases in red cell cyanide concentrations into the toxic range, experimental ewes and fetuses never developed toxic red cell cyanide levels (ewes P < .003, fetuses P < .004). These data, if applicable to humans, suggest that coadministration of sodium thiosulfate with SNP to pregnant women at doses currently in use for nonpregnant patients will prevent fetal, as well as maternal, cyanide toxicity.
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U2 - 10.1097/00000539-199705000-00031
DO - 10.1097/00000539-199705000-00031
M3 - Article
C2 - 9141943
AN - SCOPUS:0030988636
SN - 0003-2999
VL - 84
SP - 1121
EP - 1126
JO - Anesthesia and analgesia
JF - Anesthesia and analgesia
IS - 5
ER -