A reproducible nonlethal animal model for studying cyanide poisoning

Previous studies using bolus intravenous injections of sodium cyanide have been used to model the sudden exposure to high concentrations of cyanide th at could occur on the battlefield. This study was designed to develop a mod el that would simulate the type of exposure to cyanide gas that could happe n during actual low-level continuous types of exposure and then compare it with the bolus model. Cardiovascular and respiratory recordings taken from anesthetized dogs have been used previously to characterize the lethal effe cts of cyanide. The intravenous, bolus injection of 2.5 mg/kg sodium cyanid e provides a model in which a greater than lethal concentration is attained . In contrast, our model uses a slow, intravenous infusion of cyanide to ti trate each animal to its own inherent end point, which coincides with the a mount of cyanide needed to induce death through respiratory arrest. In this model, therapeutic intervention can be used to restore respiration and all ow for the complete recovery of the animals. After recovery, the same anima l can be given a second infusion of cyanide, followed again by treatment an d recovery, providing a reproducible end point. This end point can then be expressed as the total amount of cyanide per body weight (mg/kg) required t o kill, In this study, the average dose of sodium cyanide among 12 animals was 1.21 mg/kg, which is approximately half the cyanide used in the bolus m odel. Thus, titration to respiratory arrest followed by resuscitation provi des a repetitive-use animal model that can be used to test the efficacy of various forms of pretreatment and/or therapy without the loss of a single a nimal.