Phân loại: crotalus Tên thường gặp: Phân loại rắn chuông Akistrodan Tên thường gặp: Cooperhead, bông miệng, nước giày của mọi da đỏ Xác định: r hình tam giác, đầu dựa trên rộng | VENOMOUS BITES AND STINGS 173 TAB LE 6-14 VENOMOUS BITES AND STINGS-NORTH AMERICA PIT VIPERS CLASSIFICATION AND IDENTIFICATION VENOM DELIVERY AND CHARACTERISTICS CLINICAL PRESENTATIONS TREATMENT Classification crotalus Common name Rattlesnake Classification Akistrodan Common names Cooperhead cotton mouth water moccasin Identification Triangular shaped broad-based head Elliptical pupils Facial pits between nostril and eye . Infrared sensing Terminal bud or rattles rattlesnakes only Retractable anterior paired fangs Mixture of enzymes peptides polypeptides proteins Causes local necrosis vascular endothelial cell lysis with increased permeability coagulopathy and neuromuscular dysfunction Venom characteristics vary between genus and species Approximately 25 of bites are nonenvenomations dry bites Local One or more puncture wounds nonclotting Persistent burning sharp pain Edema progressing beyond puncture site Local paraesthesias May see ecchymosis and blister formation Systemic Anxiety Nausea and vomiting Perioral and extremity paresthesias Weakness Alteration in taste metallic Spontaneous bleeding . hematuria GI bleed Coagulopathy decreased platelets fibrinogen Increased PT FDP Tachypnea tachycardia Hypotension shock Prehospital Remove all constricting jewelry . rings Extremity bites immobilized in semidependance position Elastic pressure wrap or non-elastic lymphatic constricting band placement Hospital care ABCs and IV x 2 Local wound care and tetanus prophylaxis Laboratory evaluation CBC platelets coagulation studies including fibrinogen and fibrin degradation products electrolytes BUN creatinine type and screen Antivenom Polyvalent crotalidae immune Fab Cro Fab Affinity purified sheep derived Fab fragments Treatment based on progression of local edema beyond puncture wounds and presence of systemic toxicity or coagulopathy Initial dose 4-6 vials IV over 1 h Repeat dose of 6 vials if initial control not obtained If initial control is obtained progression of
