given Once the allergic symptoms have resolved, a minimum of minutes should pass, then the infusion should be restarted at a slower rate After the initial dose of CroFab is given, a repeat dose may be required if there is progression of envenomation Additional doses of four to six vials should be administered repeatedly until initial control of the envenomation syndrome has been achieved Once there is no progression, two vials are administered every hours for three additional doses TABLE 90.24 GRADING OF CROTALID (PIT VIPER) SNAKEBITES Local Mild Moderate Severe Fang mark All local signs extend beyond wound site Entire extremity involvement Intense pain Edema Erythema Systemic Laboratory Ecchymosis ± Vesicles Within 10–15 cm of bite None Nausea/vomiting Anxiety related Weakness/fainting Perioral, scalp paresthesias Metallic taste Pallor No abnormalities Tachycardia Mild hypotension Fasciculations Hemoconcentration Thrombocytopenia Hypofibrinogenemia As in moderate Hypotension Shock Bleeding diathesis Respiratory distress Significant anemia Prolonged clotting time Metabolic acidosis Patients with dry bites and only a simple wound need to be monitored for a minimum of hours, with laboratory studies repeated prior to discharge to rule out a delayed onset of signs of envenomation Patients who present to the hospital more than hours from their initial bite can be observed for only to hours, and those with normal vital signs and physical exam and no concerning laboratory findings may be safely discharged Minor local symptoms with no signs of systemic toxicity warrant a 12 to 24-hour observation time All patients receiving CroFab should be admitted to the hospital for monitoring and upon discharge need to be reassessed to days and to days after their last antivenom dose as recurrent coagulopathy can develop and persist for week or longer Wound care includes irrigation, cleansing, a loose dressing, and tetanus prophylaxis Cotton padding can be used between swollen digits, and analgesics provided as needed Current studies question the need for prophylactic antibiotics Surgical excision of the wound, routine fasciotomy, and application of ice are contraindicated Excision of the wound does not remove significant venom after 30 minutes, and cryotherapy has been associated with increased extremity necrosis and amputations Fasciotomy should be reserved for the rare case of a true compartment syndrome Necrosis is usually the result of the proteolytic enzymes or inappropriate therapy and is not typically caused by increased compartmental pressure Superficial debridement may be required at to days; one possible wound care regimen suggested at this stage includes local oxygen, aluminum acetate (1:20 solution) soaks, and triple dye Physical therapy is beneficial during the healing phase Supportive care focuses on correction of the intravascular depletion that results from increased venous capacitance, interstitial third spacing, and hemorrhagic losses There should be two IV lines for antivenin therapy and volume replacement Shock usually develops between and 24 hours after the snakebite but may present within the first hour in severe envenomation Central vascular monitoring and accurate urine output measurements are desirable for optimal therapy Normal saline or lactated Ringer solution (20 mL/kg over hour), followed by fresh whole blood or other blood components, often corrects the hypovolemia (see Chapter 10 Shock ) Vasopressors are usually needed only transiently in the more severe cases A bleeding diathesis is best managed with fresh whole blood, or blood component therapy, primarily packed red blood cells (10 mL/kg), and fresh-frozen plasma (10 mL/kg) With life-threatening bleeding, platelets (0.2 units/kg) and a more concentrated fibrinogen source (cryoprecipitate —dose one bag per kg body weight) should also be considered Abnormal clotting parameters, including fibrinogen and platelet and blood counts, should be reevaluated every to hours Respiratory and renal support may also be required The rate of serum sickness with CroFab is much lower than that seen with older products Signs of serum sickness include rashes, arthralgias, edema, malaise, lymphadenopathy, fever, and/or GI symptoms that evolve over several days Prednisone (2 mg/kg/day, maximum 80 mg) until symptoms abate (and then a tapering schedule) has been used with success in most cases Diphenhydramine (5 mg/kg/day in four divided doses, max 50 mg/dose) is often given as an adjunct Coral snake When coral snake wounds are present or the history or specimen is consistent with an Eastern or Texas coral snakebite, antivenin for M fulvius (Wyeth) if available should be administered before development of further symptoms As Wyeth no longer manufactures the coral snake antivenin and there are currently no other FDA-approved alternatives in the United States, there have been multiple extensions of the original expiration date on vials Hence, in the United States, antivenin should be restricted to patients with systemic symptoms This antivenin is also an equine serum and requires preliminary skin testing (see package insert), although 10% of patients can have a false-negative test Pediatric patients should be closely monitored for signs of anaphylaxis The use of antivenin in pregnancy should be considered on a case-by-case basis The initial recommended dosage is three to five vials by IV; an additional three to five vials may be given as needed for signs of venom toxicity There is no antivenin available for the Arizona coral snake (M euryxanthus ) Supportive care should provide a satisfactory outcome in these cases Constriction bands, suction and drainage, and other local measures not retard coral snake venom absorption, and hence are not indicated All patients that present to the ED with a coral snakebite should be observed for at least 24 hours Exotic snakes The clinician confronted with an exotic snakebite or a clinician inexperienced in snakebites should consult a local medical herpetologist or the American Association of Zoologic Parks and Aquariums and the American Association of Poison Control Centers These centers keep an up-to-date database of exotic antivenoms Access to this information is available at 800-222-1222 Report all illegally possessed reptiles to the police or to the appropriate fish and game agency Venomous lizards The two lizards that are potentially dangerous for humans that the emergency provider needs to be aware of are the Gila monster (Heloderma suspectum ) of the southwestern United States and adjacent areas of Mexico and the Mexican beaded lizard (Heloderma horridum ) of western Mexico south to Guatemala Their venom from submandibular glands contains peptides, such as exendins-3 and -4, which are glucagon-like peptide-1 analogs Bites are typically provoked and can cause severe local pain, swelling, and regional lymphadenopathy along with systemic symptoms, such as dizziness, hypotension, angioedema, sweating, rigors, tinnitus, nausea, and vomiting ... preliminary skin testing (see package insert), although 10% of patients can have a false-negative test Pediatric patients should be closely monitored for signs of anaphylaxis The use of antivenin in... game agency Venomous lizards The two lizards that are potentially dangerous for humans that the emergency provider needs to be aware of are the Gila monster (Heloderma suspectum ) of the southwestern