Conclusions
In our model of intravenous methanethiolate poisoning, IV HOC administration resulted in a transient improvement in vital signs and prolonged time to death; however, it did not improve survival.
Methods
Sixteen anesthetized swine received IV sodium methanethiolate to apnea and were randomized to receive either IV HOC or no treatment. Physiologic and laboratory parameters were monitored throughout the study. Power analysis indicated that 8 animals per group would be sufficient to find a moderate effect (f = 0.24) with 2 groups, α = 0.05, and 80% power.
Results
Both groups were similar in baseline characteristics. Following treatment, the HOC group had significantly higher heart rate and blood pressure at 5-10 minutes post-apnea, higher systemic vascular resistance at 5 minutes post-apnea, higher tidal volume, higher end-tidal carbon dioxide, and lower end-tidal oxygen 10-15 minutes post-apnea compared with controls. None of the animals survived to the end of the study (60 minutes). The Kaplan-Meier survival curves were significantly different between cohorts (log-rank p = 0.0321), with the HOC group surviving longer than controls (32.4 ± 7.3 vs. 25.8 ± 1.0 minutes). Conclusions: In our model of intravenous methanethiolate poisoning, IV HOC administration resulted in a transient improvement in vital signs and prolonged time to death; however, it did not improve survival.