In a recent case series from central Arizona, 32% of patients developed new or recurrent hematologic abnormalities after initial control [31]. Finally,

the panelists noted that the safety of a “watchful waiting” strategy is wholly dependent on the quality and frequency of follow-up observations, which may vary depending on local hospital resources and staffing patterns. In light of the above information, the practice of administering maintenance antivenom therapy is controversial. Inhibitors,research,lifescience,medical Historically, some centers recommend maintenance therapy universally, while others do so in the minority of cases [26,39,40]. Given the wide Cytoskeletal Signaling inhibitor variation in clinical practice patterns the panelists concluded that a “one size fits all” or simplified decision rule was inappropriate for the question of whether to administer Inhibitors,research,lifescience,medical maintenance therapy. The panel recommended consultation with a regional poison center or local snakebite treatment expert to assist in the determination of whether to give maintenance antivenom therapy. Management of patients with apparent dry bites or minor envenomations (boxes 9 and 10) Approximately 20 – 25% of

crotaline snakebites are “dry”; no venom effects develop [18]. Although the majority of patients with apparent dry bites have not been envenomated, some patients who initially present with a wound but no other signs of envenomation (i.e. no swelling, ecchymosis, Inhibitors,research,lifescience,medical vesicle formation, or hematologic or systemic venom effects) develop signs of envenomation after a latent period of minutes to hours [53]. In addition, some patients present with apparent minor venom effects (ecchymosis, swelling, and/or vesicles limited to

the immediate area of the bite site without systemic Inhibitors,research,lifescience,medical venom effects). All panel members reported having treated patients who presented in this manner and subsequently developed significant progressive signs of envenomation. To our knowledge, there are no data to describe the typical time course or define a “safe” period of observation Inhibitors,research,lifescience,medical after which the risk of delayed-onset venom effects is minimal, although the best available evidence suggests that 6 hours is not long enough in many cases [53]. Cost-benefit implications are largely unknown. The panel members recommended that, in general, patients with apparent non-envenomation be observed in a health care facility for 3-mercaptopyruvate sulfurtransferase at least 8 hours, with repeat platelet count, prothrombin time, fibrinogen, and hemoglobin measurement prior to discharge. Anecdotal evidence suggests some patients, such as children and those with lower extremity envenomations, may develop significant tissue effects more than 8 hours after an apparent dry bite, and therefore may require longer observation. Patients with apparently minor envenomation and no evidence of progression should be observed longer, in the range of 12 – 24 hours.