SnakebiteSnakebite Traci Denton RN, CCRNTraci Denton RN, CCRN

Snakes in TennesseeSnakes in Tennessee

Tennessee is home to 32 species of snakes; 4 Tennessee is home to 32 species of snakes; 4 of which are venomous.of which are venomous.

Poisonous is not the correct terminology Poisonous is not the correct terminology (poison is ingested and venom is injected.)(poison is ingested and venom is injected.)

All of Tennessee’s venomous snakes are from All of Tennessee’s venomous snakes are from the Pit Viper family. They get that name from the Pit Viper family. They get that name from having a heat sensing pit just behind each having a heat sensing pit just behind each nostril, which they use in sensing their prey.nostril, which they use in sensing their prey.

The 4 venomous snakes in Tennessee are: The 4 venomous snakes in Tennessee are:

The Western The Western CottonmouthCottonmouth

Of all the venomous snakes in Tennessee, the Cottonmouth has the meanesttemperament. They will stand their ground when encountered, and they will give you a good dose of venom with each bite. It can bite underwater. Allsnakes in Tennessee have white mouths; so do not base your identificationon that criterion alone.

The Timber Rattlesnake The Timber Rattlesnake

Timber rattlesnakes are a secretive, nonaggressive species. Their main defense is tolie motionless on the forest floor, relying on their color and pattern to camouflage them from predators.

The Northern and The Northern and Southern CopperheadSouthern Copperhead

The Copperhead is a relatively shy snake, but they account for the most reported bites each year in Tennessee. They inject venom based on the amount required to render its prey inactive. They know that they cannot digest a human, so roughly 50% of their bites are dry bites (no venom injected)

The Western Pigmy The Western Pigmy Rattlesnake Rattlesnake

This is one of the smallest species of rattlesnakes in North America. The end of the tail has a small rattle on it that is seldom louder than a buzzinginsect and is often not heard or even seen. The bite from this species is rarely fatal.

Worldwide, there are 50,000 deaths from venomous Worldwide, there are 50,000 deaths from venomous snakebites each year.snakebites each year.

Only 12-15 are in the USAOnly 12-15 are in the USA

In Tennessee, only 4 snakebite related deaths have In Tennessee, only 4 snakebite related deaths have been reported since 1960.been reported since 1960.

Most Tennessee snakes are nocturnal during summer Most Tennessee snakes are nocturnal during summer months and only lay in midday sun to warm.months and only lay in midday sun to warm.

In early spring and late fall, they are more prevalent In early spring and late fall, they are more prevalent in daylight hours when temperatures are higher.in daylight hours when temperatures are higher.

Tennessee snakes hibernate in winter and prefer Tennessee snakes hibernate in winter and prefer temperatures > 50 F and < 100 F.temperatures > 50 F and < 100 F.

Most bites occur when people are trying to kill Most bites occur when people are trying to kill or handle a snake. Snakes will always flee an or handle a snake. Snakes will always flee an area rather than strike, unless they are area rather than strike, unless they are harassed or startled. More people die from harassed or startled. More people die from bee stings and lightening strikes annually .bee stings and lightening strikes annually .

Immediate medical help should be sought in Immediate medical help should be sought in case a bite occurs.case a bite occurs.

This is where we come This is where we come in…..in…..

Coagulation abnormalities are due directly to Coagulation abnormalities are due directly to snake venom interference with the coagulation snake venom interference with the coagulation

cascadecascade

Pharmacotherapy Pharmacotherapy PearlsPearls

Minimal envenomationMinimal envenomation: Swelling, pain, and : Swelling, pain, and bruising are limited to immediate bite site: no bruising are limited to immediate bite site: no systemic signs and symptoms; normal coagulation systemic signs and symptoms; normal coagulation parameters; no clinical evidence of bleeding.parameters; no clinical evidence of bleeding.

Moderate envenomationModerate envenomation: Swelling, pain, and : Swelling, pain, and bruising are limited to less than a full extremity bruising are limited to less than a full extremity (or<50 cm if bite was on head or trunk); systemic (or<50 cm if bite was on head or trunk); systemic signs and symptoms are not life threatening signs and symptoms are not life threatening (nausea, vomiting, oral paresthesia, unusual taste, (nausea, vomiting, oral paresthesia, unusual taste, mild hypotension, mild tachycardia, tachypnea); mild hypotension, mild tachycardia, tachypnea); coagulation parameters may be abnormal; no coagulation parameters may be abnormal; no bleeding other than minor hematuria, gum bleeding other than minor hematuria, gum bleeding or nosebleeds, if not severe.bleeding or nosebleeds, if not severe.

Severe envenomationSevere envenomation: Swelling, pain, and : Swelling, pain, and bruising involve more than the entire bruising involve more than the entire extremity or threaten the airway; systemic extremity or threaten the airway; systemic signs and symptoms are markedly abnormal signs and symptoms are markedly abnormal (severe alteration of mental status, severe (severe alteration of mental status, severe hypotension, severe tachycardia, tachypnea, hypotension, severe tachycardia, tachypnea, respiratory insufficiency); coagulation respiratory insufficiency); coagulation parameters are abnormal; serious bleeding or parameters are abnormal; serious bleeding or severe threat of bleeding.severe threat of bleeding.

Treatment……..Treatment……..

CroFab is a venom-specific fragment of IgG, which binds and neutralizesVenom toxin, helping to remove the toxin from the target tissue and Eliminate it from the body.

Dosing: Adult Dosing: Adult Crotalid envenomationCrotalid envenomation

Initial doseInitial dose: 4-6 vials, dependent upon : 4-6 vials, dependent upon patient response. Treatment should begin patient response. Treatment should begin within 6 hours of snakebite; monitor for 1 within 6 hours of snakebite; monitor for 1 hour following infusion. Repeat with an hour following infusion. Repeat with an additional 4-6 vials if control is not achieved additional 4-6 vials if control is not achieved with initial dose. Continue to treat with 4-6 with initial dose. Continue to treat with 4-6 vial doses until complete arrest of local vial doses until complete arrest of local manifestations, coagulation tests and manifestations, coagulation tests and systemic signs are normal. Monitor closely.systemic signs are normal. Monitor closely.

Maintenance doseMaintenance dose: Once control is achieved, administer : Once control is achieved, administer 2 vials every 6 hours for up to 18 hours. Optimal dosing 2 vials every 6 hours for up to 18 hours. Optimal dosing past 18 hours has not been established; however, past 18 hours has not been established; however, treatment may be continued if deemed necessary based on treatment may be continued if deemed necessary based on the patient’s condition.the patient’s condition.

Dosing: Geriatric Dosing: Geriatric Refer to adult dosingRefer to adult dosing

Dosing: Pediatric Dosing: Pediatric Refer to adult dosingRefer to adult dosing

Note: Clinical trials included patients as young as 11 years Note: Clinical trials included patients as young as 11 years of age. Specific pediatric studies have not been conducted. of age. Specific pediatric studies have not been conducted. Because the absolute venom dose is expected to be the Because the absolute venom dose is expected to be the same in adults and children, adult dosing should be used.same in adults and children, adult dosing should be used.

Products contain thimerosal with 0.11 mg of mercury per Products contain thimerosal with 0.11 mg of mercury per vial , which in high doses has been associated with vial , which in high doses has been associated with neurological and renal toxicity. Fetuses and very young neurological and renal toxicity. Fetuses and very young children are most susceptible for mercury related toxicities.children are most susceptible for mercury related toxicities.

Reconstitution:Reconstitution:

Reconstitute each vial with 10 mL sterile Reconstitute each vial with 10 mL sterile water for injection and mix by gentle swirling. water for injection and mix by gentle swirling. Further dilute total dose in 250 ml NS: use Further dilute total dose in 250 ml NS: use within 4 hours of reconstitution.within 4 hours of reconstitution.

NoteNote: Reconstitution with 25 mL sterile : Reconstitution with 25 mL sterile water for infusion and hand rolling/inverting water for infusion and hand rolling/inverting may result in shorter dissolution times and may result in shorter dissolution times and allow for more rapid administration.allow for more rapid administration.

Administration: I.V.Administration: I.V.

Administer I.V. over 60 minutes at a rate of Administer I.V. over 60 minutes at a rate of 25-50 mL/hour for the first 10 minutes. If no 25-50 mL/hour for the first 10 minutes. If no allergic reaction is observed, increase rate to allergic reaction is observed, increase rate to 250 mL/hour. Monitor closely. Epinephrine 250 mL/hour. Monitor closely. Epinephrine and diphenhydramine should be available and diphenhydramine should be available during the infusion. during the infusion.

Decreasing the rate of infusion may help Decreasing the rate of infusion may help control some adverse effects.control some adverse effects.

Contraindications:Contraindications:

Hypersensitivity to any component of the Hypersensitivity to any component of the formulation (including papaya or papain), unless formulation (including papaya or papain), unless benefits outweigh the risks and appropriate benefits outweigh the risks and appropriate management for anaphylaxis is readily available. management for anaphylaxis is readily available.

Processed with papain and my cause Processed with papain and my cause hypersensitivity reactions in patients allergic to hypersensitivity reactions in patients allergic to papaya, other papaya extracts, papain, papaya, other papaya extracts, papain, chymopapain, or the pineapple-enzyme chymopapain, or the pineapple-enzyme bromelain. There may also be cross allergencity bromelain. There may also be cross allergencity with dust mite and latex allergens.with dust mite and latex allergens.

Adverse effects:Adverse effects:

Hypersensitivity reactions: Derived from Hypersensitivity reactions: Derived from sheep plasma; anaphylaxis and anaphylactoid sheep plasma; anaphylaxis and anaphylactoid reactions are possible, especially in patients reactions are possible, especially in patients with known allergies to sheep protein. with known allergies to sheep protein. Immediate treatment (including epinephrine Immediate treatment (including epinephrine 1:1000) for anaphylactoid and/or 1:1000) for anaphylactoid and/or hypersensitivity reactions should be available. hypersensitivity reactions should be available. Incidence of acute hypersensitivity reactions Incidence of acute hypersensitivity reactions may be lower than previously thought. This may be lower than previously thought. This product lacks the immunogenic Fc fragments product lacks the immunogenic Fc fragments and proteins found in the older equine-derived and proteins found in the older equine-derived product. Sensitization may occur with product. Sensitization may occur with repeated doses.repeated doses.

Adverse Reactions:Adverse Reactions:

Cardiovascular: HypotensionCardiovascular: Hypotension

Central nervous system: ChillsCentral nervous system: Chills

Dermatologic: Pruritus, rash, urticariaDermatologic: Pruritus, rash, urticaria

Respiratory: Asthma, cough, dyspnea, Respiratory: Asthma, cough, dyspnea, wheezingwheezing

Miscellaneous: Anaphylaxis, anaphylactoid Miscellaneous: Anaphylaxis, anaphylactoid reaction, hypersensitivity reactions (5% to reaction, hypersensitivity reactions (5% to 19%), serum sickness (5%)19%), serum sickness (5%)

Drug Interactions:Drug Interactions:

There are no known significant interactions.There are no known significant interactions.

Lactation: Excretion in breast milk Lactation: Excretion in breast milk unknown/use cautionunknown/use caution

Disease-related Disease-related concerns:concerns:

CroFab should be used within 4-6 hours of CroFab should be used within 4-6 hours of snakebite to prevent clinical deterioration and snakebite to prevent clinical deterioration and development of coagulation abnormalities. These development of coagulation abnormalities. These are due directly to snake venom interference with are due directly to snake venom interference with the coagulation cascade. Recurrent coagulopathy the coagulation cascade. Recurrent coagulopathy occurs in approximately 50% of patients and may occurs in approximately 50% of patients and may persist for 1-2 weeks or more. Repeat dosing may persist for 1-2 weeks or more. Repeat dosing may be indicated. Patients should be monitored for at be indicated. Patients should be monitored for at least 1 week and evaluated for other pre-existing least 1 week and evaluated for other pre-existing conditions associated with bleeding disorders. In conditions associated with bleeding disorders. In severe envenomations, a decrease in platelets severe envenomations, a decrease in platelets may occur, lasting hours to several days. Blood may occur, lasting hours to several days. Blood products are generally ineffective as they are products are generally ineffective as they are rapidly consumed by circulating venom.rapidly consumed by circulating venom.

Monitoring:Monitoring:

Parameters: Vital signs, CBC, platelet count, Parameters: Vital signs, CBC, platelet count, prothrombin time, aPTT, fibrinogen levels, prothrombin time, aPTT, fibrinogen levels, fibrin split products, clot retraction, bleeding fibrin split products, clot retraction, bleeding and coagulation times, BUN, electrolytes, and coagulation times, BUN, electrolytes, bilirubin, size of bite area (repeat every 15-30 bilirubin, size of bite area (repeat every 15-30 minutes); intake and output, signs and minutes); intake and output, signs and symptoms of anaphylaxis/allergy.symptoms of anaphylaxis/allergy.

CBC, platelet counts, and clotting studies are CBC, platelet counts, and clotting studies are evaluated at 6-hour intervals until patient is evaluated at 6-hour intervals until patient is stable.stable.

Size of bite area Size of bite area marked every 15 marked every 15

minutesminutes

CostCost

Generic not available in the U.S.Generic not available in the U.S.

Pricing (Pricing (www.drugstore.com) is $4687.76 ) is $4687.76 (2vials)(2vials)

ReferencesReferences

Buchanan JA, Varney SM, Mlynarchek SL, et al, “Immediate Adverse Events (AEs) Buchanan JA, Varney SM, Mlynarchek SL, et al, “Immediate Adverse Events (AEs) After Administration of Crotalidae Polyvalent Immune Fab,” After Administration of Crotalidae Polyvalent Immune Fab,” Clin ToxicolClin Toxicol, 2009, , 2009, 47(7):703.47(7):703.

Cannon R, Ruha AM, and Kashani J, “Acute Hypersensitivity Reactions Assocoated Cannon R, Ruha AM, and Kashani J, “Acute Hypersensitivity Reactions Assocoated With Administration of Crotalidae Polyvalent Immune Fab Antivenom”, With Administration of Crotalidae Polyvalent Immune Fab Antivenom”, Ann Ann Emergency MedicineEmergency Medicine, 2008, 51(4):407-11., 2008, 51(4):407-11.

Crotalidae Polyvalent ImmuneCrotalidae Polyvalent Immune

Duke, J, “The Venomous Snakes in Tennessee”, Duke, J, “The Venomous Snakes in Tennessee”, About.com Guide.About.com Guide.

Levonas EJ, Kokko J, Schaeffer TH, et al “Short-Term outcomes After Fab Antivenom Levonas EJ, Kokko J, Schaeffer TH, et al “Short-Term outcomes After Fab Antivenom Therapy for Severe Crotaline Snakebite,” Ann Emerg Med, 2011, 579(2): 128-Therapy for Severe Crotaline Snakebite,” Ann Emerg Med, 2011, 579(2): 128-37[PubMed20952098].37[PubMed20952098].

Ohio Valley Poisonous Snakes: Kentucky, Ohio, Tennessee, West Virginia, and Ohio Valley Poisonous Snakes: Kentucky, Ohio, Tennessee, West Virginia, and Indiana, Indiana, OhioValleyFishing.comOhioValleyFishing.com, 2011., 2011.

Quan, AN, Quan D, and Curry SC, “Improving Crotalidae Polyvalent Immune Fab Quan, AN, Quan D, and Curry SC, “Improving Crotalidae Polyvalent Immune Fab Reconstitution Times, “Reconstitution Times, “Am J Emerg MedAm J Emerg Med,2010, 28(5):593-3 {PubMed 20579555],2010, 28(5):593-3 {PubMed 20579555]