Signs and symptoms differentiating mild, moderate, and severe presentations of neurotoxic, hemotoxic, and cytotoxic syndromes are detailed below. Rapid reference criteria for determining severity by syndrome is included in the STAT treatment algorithms for symptomatic patients with NEURO and HEMO/CYTO envenomations.

Clinical Pearl: Worsening progressive pain may be present with any syndrome. Increasing pain severity and/or ascending pain up the bitten limb may be present for all snake envenomations and is an early diagnostic indicator of envenomation. Edema and/or blistering with progressive pain is the definition of the cytotoxic syndrome. If there is worsening pain with hemotoxic or neurotoxic symptoms, chart it and expect improvement after the appropriate antivenom dose.

Clinical Pearl: Treatment Endpoint = Control. Snakebite treatment is dynamic and the total dose of antivenom needed is determined by the amount of venom injected into the patient. Continue administering antivenom according to the STAT treatment algorithms until Initial Control has been achieved – refer to Defining Initial Control by Syndrome for specific clinical endpoints indicating that initial control has been achieved. When initial control is maintained through all the assessment points detailed in the control algorithm, then permanent control has been achieved.