ABSTRACT
Snake envenomations in Southern Africa are common, especially in rural areas near the eastern coast, and present a significant health care burden. The South African Vaccine Producers (SAVP) make two antivenoms that are readily available in Southern Africa. These include the monovalent antivenom, which is specific to the Boomslang (Dispholidus typus), and the polyvalent antivenom, which is effective for 10 of the more common and dangerous species.
When patients present to a hospital following a snake envenomation, the offending species is rarely positively identified. A syndromic approach to snake envenomations based on patient symptomatology has therefore been developed. The three presenting syndromes are painful progressive swelling from predominantly cytotoxic venom; progressive weakness from predominantly neurotoxic venom effects; and coagulopathy with bleeding from predominantly hemotoxic venom. Each syndrome has specific management principles. A rare fourth syndrome, acute venom-induced anaphylaxis, is also recognized and occurs in individuals who have had previous exposure to venoms (usually in snake-handlers). It is important to note that there may be overlap of these syndromes. The majority of envenomations that present to hospital in Southern Africa are cytotoxic with painful progressive swelling. These can often be managed without the use of antivenom with simple limb elevation and analgesia. Antibiotics are not routinely used, and tourniquet usage is not recommended. Antivenom is indicated in patients with rapid-onset painful progressive swelling or those with impending compartment syndrome. All patients presenting with coagulopathy with bleeding and progressive weakness require antivenom. Antivenom is associated with a high rate of anaphylaxis, especially in children. It must therefore only be administered when absolutely indicated and in a controlled high care setting. Fasciotomy is indicated in patients with compartment syndrome. It is often difficult to diagnose compartment syndrome clinically in cytotoxic envenomations, and intracompartment pressure monitors or ultrasound may assist in confirming the diagnosis. Antivenom should always be considered prior to performing a fasciotomy to decrease intraoperative bleeding.
