Be familiar with the various types of Crotalidae snakes that are present in our region
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Be familiar with the various types of Crotalidae snakes that are present in our region Be familiar with the various types of Crotalidae snakes that are present in our region Discuss the primary signs and symptoms of Crotalidae envenomation Develop a treatment plan, for both stabilization and treatment of Crotalidae envenomations Develop a treatment plan, for both stabilization and treatment of Crotalidae envenomations Be familiar with the various types of Micrurus snakes that are present in our region Be familiar with the various types of Micrurus snakes that are present in our region Discuss the primary signs and symptoms of Micrurus envenomation Develop a treatment plan, for both stabilization and treatment of Micrurus envenomation Develop a treatment plan, for both stabilization and treatment of Micrurus envenomation Snakes in Texas Snakes in Texas 155 species altogether 15 species are venomous (10-15% of snakes) deaths in Texas from snakebites = 2-3/year Snakes in Texas Snakes in Texas compare to insect bites: 5-7/year compare to lightning strikes: ~8/year Venomous snakes bite 7000-8000 people annually Venomous snakes bite 7000-8000 people annually occurred while snake handling = ~3000 accidental = 4000-5000 Venomous snakes bite 7000-8000 people annually Venomous snakes bite 7000-8000 people annually 85% of natural bites are below the knee Epidemiology Epidemiology male > female by 9:1 average age = 24 Significant rates of intoxication at time of bites (28%) Most bites aren’t lethal!! Most bites aren’t lethal!! Be concerned about: very old very young very sick very pregnant Anaphylaxis risk Anaphylaxis risk Good first aid/wound care avoid: ice, shock, cowboy treatment, and tourniquet Remain calm and seek medical attention Sistrurus Agkistrodon Agkistrodon Usually rattle before biting but not always Usually rattle before biting but not always Rattles can fall off with trauma, so may not be present Accounts for average of 5.5 deaths/year in US Accounts for average of 5.5 deaths/year in US 50% of all bites occur in 18-28-year-old group; young males most common Modified saliva: digests the tissue in the affected area Modified saliva: digests the tissue in the affected area 90% water 5-15 enzymes 3-12 proteins Potency and effects vary by species and individual snake: ~25% of bites are “dry” Potency and effects vary by species and individual snake: ~25% of bites are “dry” Local symptoms Local symptoms skin necrosis tissue sloughing Histotoxic Histotoxic hyaluronidase collagenase metalloproteinase Edema: stimulation of the inflammatory cascade Hematologic mediators Hematologic mediators main one is fibrinolysis defibrination, without DIC (disseminated intravascular coagulation) Hematologic mediators Hematologic mediators thrombocytopenia (unknown mechanism) uncommonly may cause generalized bleeding labs: abnormal for up to a week; reports of relapse labs: abnormal for up to a week; reports of relapse elevated fibrin split products elevated PT (prothrombin time) low fibrinogen DIC is uncommon – if it occurs it is the primary reason for mortality Local mediators Local mediators VMPs (venom metalloproteinases): cleave/activate TNF (tumor necrosis factor) alpha,… Local mediators Local mediators …which then cleaves endogenous metalloproteinases = amplification Local mediators Local mediators myotoxin A necrosis of skeletal muscle may cause distant rhabdomyolysis Local mediators Local mediators pain and edema rapid edema indicative of severe envenomation bullae formation/blebs not uncommon Do nothing that delays getting to ED (emergency department) Do nothing that delays getting to ED (emergency department) Basic and advanced life support Basic and advanced life support Mark border of advancing edema with pen every 15 minutes No benefit with negative pressure venom extraction device No benefit with negative pressure venom extraction device Fang marks not recommended Fang marks not recommended Mouth suction contraindicated Constriction and pressure immobilization: may help impede spread of venom Tourniquets not recommended Keep in neutral position Do not give antivenom in field secondary to anaphylaxis risk Do not give antivenom in field secondary to anaphylaxis risk Do not try and find snake Do not try and find snake may result in more bites may delay ED arrival Grading based on clinical presentation Grading based on clinical presentation Dry bite puncture wound only no systemic effect normal labs Mild Mild local effects at bite site only no systemic effects normal labs Moderate Moderate local effects beyond immediate bite area vomiting, metallic taste, fasciculation Moderate Moderate platelets <90,000, fibrinogen <90-100 mg/dl PT >14 seconds CPK (creatine phosphokinase) >500-1,000 U/L Severe Severe rapid involvement of entire area near bite compartment syndrome systemic shock severe bleeding Severe Severe renal failure respiratory difficulty altered mental status platelets <20,000 rhabdomyolysis Derived from horse serum immunized with venom from various species Derived from horse serum immunized with venom from various species Used for moderate to severe symptoms Used for moderate to severe symptoms test dose for anaphylaxis – skin testing Used for moderate to severe symptoms Used for moderate to severe symptoms start with 10 vials (average 10-15 for moderate bite) – can go up to 25-30 vials Used for moderate to severe symptoms Used for moderate to severe symptoms ~80% develop serum sickness 0-3 minimal severity 0-3 minimal severity 4-7 moderate severity 8-20 severe Fever Fever Redness of joints Skin rash Itching Swollen glands Malaise Anorexia Patient has to be hospitalized to treat Patient has to be hospitalized to treat Sheep-derived antivenin Sheep-derived antivenin venom-specific Fab fragment of immunoglobulin G (IgG) binds and neutralizes venom toxins Because the antibodies are raised in sheep there is minimal to no serum sickness Because the antibodies are raised in sheep there is minimal to no serum sickness Start with 4-6 vials Administer 4-6 more vials every hour until coagulopathies and edema have been controlled Administer 4-6 more vials every hour until coagulopathies and edema have been controlled After initial control, provide 2 vials every 6 hours for 18 hours Increased pressure within the fixed compartment of the limb muscle fascia Increased pressure within the fixed compartment of the limb muscle fascia Symptoms Symptoms skin is taught, warm, blanched distal to the swelling may have numbness, loss of blood supply Diagnosis: made by percutaneous insertion of needle with measurement of internal pressure Diagnosis: made by percutaneous insertion of needle with measurement of internal pressure Treatment Treatment surgical release fasciotomy With antivenin, may have some disfigurement, rare functional impairment, and even rarer loss of a limb With antivenin, may have some disfigurement, rare functional impairment, and even rarer loss of a limb Red touches yellow: kill a fellow Red touches yellow: kill a fellow Red touches black: a friend of Jack Micrurus sp. Micrurus sp. Systemic effects may be delayed >12 hours May require antivenin!! Neurotoxic, neuromuscular dysfunction Neurotoxic, neuromuscular dysfunction Little enzymatic activity, low necrotic potential Little venom delivered per bite Primitive delivery system Primitive delivery system small mouth pair of small, fixed hollow fangs on anterior mouth Primitive delivery system Primitive delivery system venom released via chewing motion – must bite and temporarily hold and “chew” to get venom out Respiratory distress Respiratory distress pharyngeal spasm hypersalivation cyanosis trismus Cardiovascular collapse Cardiovascular collapse Onset: symptoms may be delayed up to 12 hours Bite site: paucity of complaints Bite site: paucity of complaints little pain no necrosis paresthesias swelling usually mild Neurotoxic Neurotoxic altered mental status can occur diplopia, ptosis generalized weakness muscle fasciculations No advantage for giving antivenom for other snake species Wyeth® Antivenin (Micrurus fulvius ) Wyeth® Antivenin (Micrurus fulvius ) dose: 3-6 vials IV (intravenously) over 1-2 hours Wyeth® Antivenin (Micrurus fulvius ) Wyeth® Antivenin (Micrurus fulvius ) if necessary, give extra 3-5 vials over 1-2 hours rarely need >10 vials Wyeth® Antivenin (Micrurus fulvius ) Wyeth® Antivenin (Micrurus fulvius ) must be started early – before any symptoms develop, as soon as they arrive at the ED Be able to recognize the clinical symptoms associated with an envenomation from a brown recluse, black widow, tarantula, scorpion, and fire ant Be able to recognize the clinical symptoms associated with an envenomation from a brown recluse, black widow, tarantula, scorpion, and fire ant Define a basic treatment plan for individuals who are bitten by the insects listed in the first objective Define a basic treatment plan for individuals who are bitten by the insects listed in the first objective Recognize the clinical symptoms associated with insect bite-associated allergic reaction – be able to define a treatment plan for the individual undergoing anaphylaxis Recognize the clinical symptoms associated with insect bite-associated allergic reaction – be able to define a treatment plan for the individual undergoing anaphylaxis Loxosceles sp. Loxosceles sp. Venom digestive enzymes sphingomyelinase D Proper wound care Proper wound care +/- debridement no prophylactic antibiotics Necrotic lesion Necrotic lesion Fever Rash Arthralgias Latrodectus sp. Latrodectus sp. Neurotoxic venom increased calcium influx increased acetylcholine Local pain Local pain Abdominal cramping Diaphoresis Nausea, vomiting, diarrhea Treatment Treatment wound care muscle relaxers opiate analgesics antivenin (rarely used) There is little toxicity associated with North American tarantulas There is little toxicity associated with North American tarantulas Apidae: honey bees Apidae: honey bees Bombidae: bumble bees Vespidae: wasps, hornets, yellow jackets Formicoidea: ants Symptoms Symptoms local pain, itching, and swelling multiple stings or stings to the face risks Symptoms Symptoms vomiting, cyanosis, hypotension, syncope, dyspnea anaphylaxis risk Treatment Treatment wound care remove stinger? analgesics antihistamines Very painful sting Very painful sting Typically supportive care is all that is needed If numbness or paresthesias persist for >48 hours need medical evaluation Dostları ilə paylaş:
