Snakebite envenomation is a complex poisoning because of the combination of the effects of venoms and the human and snake variables that influence venom toxicity Venoms are mixtures of potent enzymes, primarily proteinases, and low– molecular-weight peptides that possess extensive pathophysiologic properties A crotalid venom often has a combination of necrotizing, hemotoxic, neurotoxic, nephrotoxic, and cardiotoxic substances Many venoms induce increased endothelial permeability and venous pooling, creating intravascular depletion A transient hemoconcentration may be present during this plasma “leak.” Hemotoxic effects induce hemolysis, fibrinogen proteolysis, and thrombocytopenia, which along with activation of plasminogen, can lead to a bleeding diathesis in severe envenomation Respiratory failure may occur because of pulmonary edema or a shock state Human factors that influence toxicity to snakebites include the victim’s size and general health and wound characteristics A small child is more susceptible to a given volume of venom than a larger person and unfortunately, young children are commonly bitten more than once Fang penetration of a vessel or subfascial compartment ensures a more rapid absorption and serious systemic effects Likewise, a bite on the head, neck, or trunk hastens systemic absorption