Snake bites and insect stings

1. Snake bites and insect stings

2. Outline • Case presentation • Clinical manifestations of snake bites • Treatment

3. Case Report • 15 y male • Barefoot • Sudden onset of pain in Lt foot • Snake seen and killed

4. Alert, in pain • Swollen leg • BP 140/85 P 110

5. Epidemiology • There are approximately 300,000 poisonous snakebites in the world each year. Approximately 10% of these bites results in death; most of these due to cobra bites in southeast Asia.

6. Poisonous Snakes in Israel • צפע א"י (Vipera palaestina)צפע חרמון (Vipera bornmuelleri)עכן קטן (Cerastes vipera)עכן גדול (Cerastes gasperetti)עכן מקורנן (Cerastes cerastes)שפיפון הנגב (Pseudocerastes fieldi)שרף עין-גדי (Atractaspis engaddensis)פתן שחור (Waltrinnesia aegyptia)אפעה מגוון (Echis coloratus)

7. צפע א"י • In Israel most cases are due to Vipera palaestina

11. צפע חרמון (Vipera bornmuelleri)

12. אפעה מגוון (Echis coloratus)

13. עכן מקורנן (Cerastes cerastes)

14. שפיפון הנגב (Pseudocerastes fieldi)

15. Clinical Manifestations • Bites usually occur on the extremities, causing burning pain and swelling at the site within minutes. • As the venom spreads to the body through the lymphatics, there is advancing edema and echymosis with lymphadenopathy.

18. Clinical Manifestations - Systemic Symptoms • Nausea and vomiting, diaphoresis, numbness or tingling around the mouth, scalp and digits and muscle fasciculations. • Generalized edema, shock, cardiac arrhythmias and death. • Clotting abnormalities are common in viper envenomations.

19. Treatment • The patient should be placed at rest with local pressure and immobilization of the involved extremity. • A tourniquet should be placed proximal to the site of envenomation ???.

20. Treatment • suction may remove some venom, in practice the procedure may aggravate bleeding, introduce infection and delay recovery. • Isotonic solutions are needed.

21. Treatment • Fresh frozen plasma, cryoprecipitate, platelet infusions - if necessary. • Tetanus prophylaxis. • A broad-spectrum antibiotic. • Antivenin - depends on the severity or rapid progression of symptoms. • Antivenin is most effective within 4 hrs from the bite; questionable value if delayed more than 12 hr.

22. Antivenins • Antivenins are animal-derived Immunoglobulins • Work by direct binding and neutralization of the antigens contained in the venom

23. Antivenins • Concentrates of animal serum. • Immediate and delayed hypersensitivity reactions are common and may themselves be life threatening.

24. System for Grading Envenomation Envenomation ReactionDosage None No local or systemic reactions No antivenin Minimal Local swelling but no systemic reactions 5 vials Moderate Swelling that progresses beyond the site of the bite together with a systemic reaction, laboratory changes, or both 10 vials Severe Marked local reaction, severe symptoms, and laboratory abnormalities 10-15 vials

25. Serum Sickness • Results from the deposition of antibody-antigen complexes on endothelial surfaces • Symptoms occur 7-21 days after administration of the antivenin and may last days or weeks

26. Serum Sickness Symptoms • Fever, malaise, lymphadenopathy, rash, arthralgia. • Arthritis, nephritis, vasculitis and neuropathy. • Treatment - Antihistamines and corticosteroids.

27. טיפול בחדר מיון נהוג לתת – 1 אמפ' ב- 100 מ"ל סליין במשך חצי שעה. ולאחר מכן את שאר הטיפול ב- 500 מ"ל סליין למשך כשעתיים.

28. Summary • Always start with ABC • For snake bite treatment with antivenin is indicated in case of systemic toxicity or rapid progression of local signs