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2/18/2019

SSSNAKES & S& S PIDER BBBITESITESITES

Theresa Matoushek, PharmD, CSPI Missouri Poison Center SSM Health Cardinal Glennon Children’s Hospital [email protected]

Objectives

1. Identify the clinical presentation of and describe the appropriate use of antivenin. 2. List the most common venomous spider bites, describe associated symptoms, and identify the appropriate treatment.

The Missouri Poison Center

• Cost effective “center of excellence” of specialized personnel and data systems.

• Multiple access routes make Poison Center services available to virtually everyone in MO 24/7/365. (toll-free phone; 800800800-800 ---222222222222----1222122212221222, text, web chat, TTY)

• Public, 911 Dispatchers, Police, EMS, Nurses, Physicians, Pharmacists, Veterinarians, and more.( 888888888-888 ---268268268268----4195419541954195 :314-268268268268----4195419541954195 )

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Population Served

• The Missouri Poison Center served all 114 Counties in 2015 • Total population ∼5 million • 2.7 million cases handled since 1974

Who is Serving Missouri?

Registered Pharmacists & Nurses who are certified as Specialists in Poison Information, clinically supervised by a board certified physician toxicologist

Poison Center Patient Care Paths

• Reassure • Provide home care and follow-up • Provide detailed consultation to doctors on hospitalized cases

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QUESTION HOW MANY EXPOSURES DOES MPC HANDLE PER YEAR?

Facts At A Glance

Envenomation is approximately 1% of our exposure calls

SNAKE BITES

3 2/18/2019

Snake Bite General Facts

OPHIDIOPHOBIA THE OF

7,000-8,000 venomous < 20 deaths bites per year in last 20 NOT a major years in US 20-25% of fanged cause of bites are DRY BITES (no injected) 2,700 death in US species 450 venomous

Venomous or NonNon----Venomous?Venomous?

NonNonNon-Non ---VenomousVenomous Snakes

• Examples: • : king, black rat, garter • NO fangs • Upper and lower row of tiny teeth • Painful but not serious • Looks similar to a human bite

Wound Tetanus Disposition care update

4 2/18/2019

Crotaline Pit Viper Family

RATTLESNAKES • Massasauga “Swamp rattler” • • Western Pygmy Rattlesnake “Ground rattler” COTTONMOUTH • Water Moccasin

COPPERHEAD • Osage • Southern • Northern • Broadbanded

Pit Viper Characteristics

• Copper-colored triangulartriangular---- shaped heads • Elliptical slitslitslit-slit ---likelike pupils • Heat sensing “pitpitpitpit” proximal to nostril • A singlesinglesingle row of subcaudal scales distal to the anal plate

Pit Viper ((CrotalidCrotalidCrotalid)) Venom

• Aqueous solution of high molecular weight that spread slowly via the • Cytotoxic andhemotoxic components • CytotoxicCytotoxic: damage tissue • HemotoxicHemotoxic: harms blood clotting system • No neurotoxic snakes in Missouri

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Clinical Presentation

• Local effects: • Fang punctures (1-4 usually) • Typically in 5 minutes: sharp, burning pain at site • 30 min to 6-8 hours: , & possible ecchymosis • Proximal edema may progress for 24-48 hours

QUESTION

T/F: Putting ice on a snake bite reduces swelling and improves outcomes.

Initial Management

• Anticipate swelling Do NOT Use • Immobilize and elevate slightly above the heart PressurePressurePressure Mark and measure swelling every IceIceIceIce Tourniquets • ImmobilizationImmobilization 15 to 30 minutes

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Medical Management

Determine the severity on Baseline labs presentation • CBC, PT/PTT, INR, fibrinogen 1 • History; location of bite; pre-hospital treatment 2 • Electrolytes, BUN, SCr • Current symptoms

Restricted mobilization Pain control • Elevate slightly above heart • Parenteral opiates such as morphine or fentanyl 3 • Activity enhances venom spread 4 • NSAIDs only if low risk of

AnxietyAnxietyAnxiety OtherOtherOther • Benzodiazepines • Tetanus booster as needed 5 • Calming environment 6 • IV Fluids

Labs & Monitoring

• Baseline CBC, PT/PTT, INR, fibrinogen, electrolytes, BUN and creatinine • Repeat in 6 hours; if within normal limits, no further labs indicated

Conservative Use of Antivenin

• Crotalidae polyvalent immune fab fragments (((CroFab(CroFabCroFabCroFab))))

Binds & neutralizes Eliminated from the body CroFabCroFabCroFab does not reverse tissue damage; it halts or Pulls away from slows its progression. tissue • Antivenin is recommended if bite is classified as mmmoderatemoderateoderate----severesevereseveresevere based on any of the 3 domains or may become so in next 666-6---1212 hourshourshours

1 2 3

Local Systemic Hematologic

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Conservative Use of Antivenin

1 Do NOT automatically give Crofab!

It is expensive and not 2 necessary in all patients.

Swelling beyond (or is anticipated to cross) elbow or knee at 6-12 hrs 3 ‰‰‰ recommend to give it

Another whwhwh

• Dry bite (venom was not injected)

• History of hypersensitivity reaction to CroFabCroFabCroFab

• History of hypersensitivity to sheep serum • Skin irritation from wool is not an allergic reaction

• History of hypersensitivity to papaya or papain • Unless benefits outweigh the potential risk & treatment is available

CroFab Contraindications

• Dry bite (venom was not injected)

• History of hypersensitivity reaction to CroFabCroFabCroFab

• History of hypersensitivity to sheep serum • Skin irritation from wool is not an allergic reaction

• History of hypersensitivity to papaya or papain • Unless benefits outweigh the potential risk & anaphylaxis treatment is available

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Proper Dosing of CroFab

• Pediatric and adult dosing is identicalidentical because it is based on severity of envenomation, not on size or age. • Reduce infusion volume of reconstituted antivenin in small children. • Establish initialinitial controlcontrol of envenomation with 4 to 6 vials of CroFab . • In adults, start the 250 mL infusion at a rate of 25 to 50 mL/hour for the first 10 minutes and observe for hypersensitivity reaction. • If no reaction occurs, complete the infusion over the next 50 to 60 minutes. Faster infusion may be indicated in critically ill patients with hemorrhage or shock.

IncidenceIncidence ofof acuteacute hypersensitivityhypersensitivity • 5%; consider risk vs benefit before giving again

Most cases are mild • Resolve spontaneously or with steroids and antihistamines

How many vials?

Most copperhead Single 444-4---vialvialvialvial initial dose bites

Most 1 or 2 initial doses of 4 to 6 vials each cottonmouth bites

Most 1 or 2 initial doses of 4 to 6 vials each rattlesnake bites In life-threatening envenomation administer 8 to 128 12 vials initially.

How to assess “control”

• Assess control of the envenomation by repeat clinicalclinical exam andand laboratorylaboratory coagulationcoagulation teststests at any time within an hour of completion of the initial CroFab dose.

Control is defined as… If control is notnotnot achieved…

• No or limited progression of local • A second 4 to 6 vial dose may be tissue effects, improved systemic beneficial. symptoms, and all coagulation •Consultation with the poison center studies and platelet counts are isis recommendedrecommended beforebefore givinggiving anyany clearly trending toward normal. repeat doses.

• Recurrence of venom effects or delayed onset of venom effects occurs in 50% of those treated with CroFab . Scheduled maintenance dosing is controversial. For this reason, additional 2-vial CroFab doses should be considered only on an “as needed” basis. • Consultation with the poison center is recommended before giving anyany “maintenance”“maintenance” dose.dose.

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Surgical Intervention

• AVOID cutting, suctioning, excising the bite Compartment syndrome = area, or exploration of the RARERARERARE in pit viper bites CONTRAINDICATED: Prophylactic Fasciotomy Venom deposited in the • Prophylactic Fasciotomy • Compartment syndrome is rare following pit viper dermal or SQ tissue bites because subfascial of venom is rare.

Edema is usually • FASCIOTOMY IS VERY RARELY INDICATED and can subcutaneous NOT sub-fascial be avoided with early and adequate administration of CroFab which prevents progression of tissue and swelling.

Disposition

Asymptomatic patients • Discharge after wound care and anti-tetanus with a dry bite update • Return if signs of envenomation develop over OR nonvenomous the next 8 to 12 hours. snakebite: Educate about good wound care, monitoring, and management at home after discharge • Observe for a minimum of 8 to 12 hours after Envenomated the bite, until stable. snakebite: • Admit if necessary for management of pain, systemic symptoms, or to administer CroFab.

Wound Care & Other Treatments

Cleanse, cover wound with sterile Surgical wound debridement at 3-10 dressing. Apply ointment. days, if necessary.

Resume activity at 3-4 days post Electric shock therapy of the wound bite. should be avoided.

Steroids should be avoided except Prophylactic should be for true allergic phenomena or avoided. Snake bites have a very low serum sickness related to CroFab. incidence of infection.

Elevate the limb as often as Do not wear anything constricting possible. Recurrent edema may until healed. occur for several MONTHS.

10 2/18/2019

SPIDER BITES

Spider Bites…In General

• 20,000 species of native spiders!

• Local Effects CCCOMMONOMMONOMMON SSSYMPTOMS • Effects vary from unnoticed to mild- • Stinging moderate symptoms • Burning • A may develop • Painful • Risk for secondary infection • Swollen • Itching • Most fangs are too small to • Redness penetrate skin and envenomate • Blanching

General Management

• Therapeutic Intervention • Wash area thoroughly with soap and water • Keep clean and dry • Do NOT apply ice • Apply a topical antibiotic or hydrocortisone 1% • Monitor for symptoms of a venomous bite

ICE

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QUESTION WHAT ARE THE VENOMOUS SPIDERS IN MISSOURI?

Venomous Spiders

BROWN RECLUSE BLACK WIDOW loxoseles latrodectus

BROWN RECLUSE

12 2/18/2019

Is it always a brown recluse?

AAALLLLLLOFOFOF THESETHESETHESE MUSTMUSTMUST BEBEBE PRESENT TOTOTO IDENTIFY ITITIT ASASASA AS AAABROWNBROWNBROWN RECLUSE :::

1. Six eyes arranged in pairs. 2. A dark violinviolinviolin shape on the cephalothorax 3. Uniformly lightlightlight-light ---coloredcolored legslegs: no stripes, no bands. 4. Uniformly colored abdomen (cream to dark brown) 5. Only fine hairs on the legs – NO spines. 6. Body length is about 3/8 inchinch. If > ½ inch, it is NOT a recluse. 7. Web is hiddenhiddenhidden from sight; never out where it can be seen.

Brown Recluse Venom

• Cytotoxic venom • L. reclusa : Most prevalent species in the US (found in Missouri, among other states); the Chilean recluse ( L. laeta ) is more potent (found in LA, Florida, and Massachusetts)

Tissue CYTOTOXIC VENOM Red Cell Lysis (uncommon)

Local Effects

Necrotic Bite site is ulceration once usually flat or center sloughs Painless initially depressed off; ulceration

Early blister and Center becomes surrounding sunken and inflammationinflammation dull/gray with significant painpainpain

Necrosis is worse if bite was in a fatty area Ulcer can takes weeks to heal Secondary infection can occur

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Systemic Effects

SSSYSTEMIC EEEFFECTSFFECTSFFECTS AAARERERE RARERARERARE

Develop General Head-to-toe Hemolysis; within 24-72 inflammatory Rarely DIC pruritic rash dark urine hours symptoms

Treatment

Recommended General wound care Medical Management Tetanus prophylaxis

Antibiotics if needed

NOT Dapsone is NOT a routine recommendation Recommended

NO benefit: injected steroids, vasodilators, electric shock Delay surgical intervention for Early excision of wound is NOT recommended and may 8 weeks prolong healing

BLACK WIDOW

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Overview ---Black Widow

• Most bites are in the Southwest US during warm months • HabitatHabitat: woodpiles, garages, rock piles • Characteristic hourglass • May or may NOTNOTNOT be visible • Juvenile and male black widows are smaller and brown

Black Widow Venom

• Neurotoxic venom • Latrodectus species (latro-) • Stimulates neurotransmitter release (acetylcholine) • Increased frequency and force of muscle contractions • NOT dermato-necrotic

BLACK Neurological WIDOW VENOM Autonomic

Local Effects

Increasing pain at Pain may radiate Painless, or the bite site Characteristic : up the limb to possible pin-prick quickly, over 15 sweating around lymph nodes or sensation min to several the bite site chest hours

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Systemic Effects

• “““L“LLLatrodectismatrodectismatrodectism”””” • Develop within 30 minutes – 2 hours • Remote or generalized pain Grade 1Grade1:1 Mild Envenomation • Headache, anxiety, “Pavor mortis” • Muscle cramping and fasciculations; writhes in pain Grade 2: • Board-like rigidity of the abdomen, shoulders, and Moderate back Envenomation • , , increased oral secretions,

, hypertension Grade 3: Severe Envenomation • Irritability, agitation • Malaise, lethargy, fever

Treatment

• Spontaneous recover expected in 24-48 hours • Death is very rare • Administer benzodiazepines to relax muscles and reduce blood pressure; opiates for intense pain • ANTIVENOMANTIVENOM: • IgG horse-serum by Merck = expired but extensions have been granted by the FDA • Administer only if patient has failed standard care • Premedicate with antihistamines • DO NOT GIVE: Calcium gluconate, dantrolene, muscle relaxers • Antibiotics are not usually needed

Resources from MPC

MISSOURIPOISONCENTER.ORG

16 2/18/2019

CASE EXAMPLE

Case Example –––Snake Bite

• An 8 yo patient presented to the emergency department 40 minutes after being bitten on the left ankle by a copperheadcopperhead while walking barefoot to the car after spending the day at the river. Two puncture are noted. There is redness but minimal swellingswelling. • Vital signs: Temp: 97.8°F BP: 95/65 mmHg HR: 100 RR: 20 • HEENT: unremarkable • Lungs: clear to auscultation • CV: normal sinus rhythm • Abd: normal bowel sounds • Neuro: alert and oriented

Case Example –––Snake Bite

1.1.1.Based on the patient’s presentation what would be thethe besbestt initial management? A. Apply ice to reduce the swelling. B. Allow the patient to ambulate and monitor the progression of symptoms. C. Obtain a baseline CBC, PT/PTT, INR, fibrinogen, electrolytes, BUN and creatinine. D. Begin a 4 vial regimen of Crofab .

2.2.2.When should labs be repeated?

3.3.3.When would we recommend CrofabCrofabCrofab ???

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SSSNAKES & S& S PIDER BBBITESITESITES

Theresa Matoushek, PharmD, CSPI Missouri Poison Center SSM Health Cardinal Glennon Children’s Hospital

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