Evaluation of the Venom Ex apparatus in the treatment of Egyptian cobra envenomation. A study in rabbits.

The Venom Ex cutting and suction apparatus for the initial treatment of snakebite was evaluated. Rabbits were injected with radioactive Egyptian cobra venom, and treatment with the Venom Ex followed. The fluid obtained by suction was analysed. All 8 control animals died within 4 hours; Venom Ex treatment resulted in the recovery of 7 out of 8 rabbits, after double the lethal dose of venom, providing treatment was started early. However, if treatment was delayed or if the dose of venom was high, there was a marked increase in the mortality. The amount of venom extracted was insufficient to account for the recovery of the animals. In one group of rabbits trauma was applied to the injection site without lacerating the skin and without removal of venom. About half of these animals recovered. However, this was less efficient than the Venom Ex treatment. Trauma apparently retards absorption of venom and increases survival. The possible reasons for this novel finding are discussed.