Snake envenomation in Saudi Arabia is usually caused by vipers, cobras, and saw-scaled vipers. Viper bites cause hemorrhagic effects while cobra bites are neurotoxic. Management involves first aid using pressure immobilization, transport to hospital, clinical assessment, possible anti-venom serum, observation for complications, and wound treatment. Controversy exists around administering anti-venom for bites with minimal effects; close observation may be preferable to immediate treatment in some cases.

2. Management of snake
Envenomation
By: Dr. Hanan Fathy Abdelaziz
Consultant of Clinical Toxicology - Al Qassim P.C.C.

3. Common Venomous Snakes In
Saudi Arabia
Levant viper
Egyptian cobra (Naja haje):

4. Puff adder
Common cobra

5. Saw-scaled viper

6. Clinical picture of
Venomenous Snake Bite

7. Clinical Picture Of Venomous Snake
Bite
Viper bite Elapidae bite
Ø Mainly hemorrhagic.
Ø Severe local reaction.
Ø Main manifestations:
 Local and systemic
bleeding.
 Hemolysis.
 Rhabdomyolysis.
O
O Mainly neurotoxic.
O Moderated local reaction.
O Main manifestations:
 Cranial nerve affection.
 Skeletal (respiratory)
muscle weakness.
 Direct cardio toxicity.

8. Clinical picture of venomous
snake bite (cont.)
Viper bite Elapidae bite
Ø Main complications
and cause of death:
 Pulmonary edema.
 Hemolysis.
 Renal failure.
 Hypotensive shock.
O Main complications and
cause of death:
 Respiratory failure.
 Myocardial depression
and cardiogenic shock.

9. Management of
Venomenous Snake
Bite

10. Venomenous snake bite

11. In Management Of Venomenous Snake
Bite
Before Discussing
WHAT TO DO
We Have To Start By
NEVER To DO
O

12. NEVER TO
O Apply tourniquet “ All what you do is to localize all
digestive enzymes”.
O Use cut and suck methods. “ Snakebite is an IM
injection. Cutting increases tissue damage to an
area already infiltrated with digestive enzymes.
O Apply any local chemicals, ice or cold packs. It does
not slow the enzyme activity. It slows the immune-
response.
O Irritate the victim.
O Be anxious.

13. Steps of Management
O First aid management (in the scene of the bite).
O Transport the victim to hospital.
O Assessment and resuscitation.
O Decision of ASV.
O Observation. (during and after ASV).
O Treatment of the bitten area (may need plastic
surgery in viper bite).
O Rehabilitation and treatment of complications.

14. First aid management
Aims of first aid management:
First aid management aims to:
O Retard systemic venom absorption.
O Arrange rapid transport of the victim to hospital.

15. Steps of First Aid
“R.I.G.H.T.”
I. Pressure Immobilization
Technique
Please pay attention to this video

16. Start by releasing any tight bandage then
Ø R. = Reassure the patient. It is the actual first
aid to slow the circulation down.
Ø I = Immobilize (as a fractured limb). Don’t apply
any compression! To spare blood supply.
Ø G. H. = Get to Hospital Immediately.
Ø T = Tell the doctor of any systemic symptoms
such as ptosis, bleeding , vomiting etc.. that
manifest on the way to hospital.

17. II. Assessment
Clinical Assessment
Factors affecting prognosis:
O Site of the bite. Head and neck and chest are
more dangerous.
O Time passed since the bite.
O Activity at the time of bite.
O Amount of venom injected and number of
bites.
O Previous state of victim’s health.

18. Clues Indicating Severe Poisoning
In Elapidae bite:
O Early weakness and dyspnea.
O Progressive local numbness.
In viper bite:
O Rapid extension of the local swelling.
O Early tender local lymph nodes.
O Early spontaneous systemic bleeding.
O Passage of dark brown/black urine.
Severe poisoning means closer monitoring

19. Laboratory Assessment
For all cases
Twenty minutes whole blood clotting test (20
WBCT):
O Place 2 ml of fresh venous blood in glass tube
without any additives and leave it undisturbed for
20 minutes. Unclotting , is diagnostic of a viper
bite (can rules out an elapid bite).
Other hematological tests:
O HB% and hematocrit value .
O Platelet count.

20. Biochemical abnormalities:
Ø ABGs : Respiratory and metabolic acidosis.
Ø Elevated ALT, AST.
Ø Bilirubin is elevated following massive hemolysis.
Ø If renal dysfunction occurs there will be elevated
urea , creatinine , K and decreased NaHCO3.
Ø Hyperkalemia and increased CPK
(Rhabdomyolysis).
Ø Urine examination: May show RBCs casts and
proteinuria.

21. Pitfalls in diagnosis of
envenomation
Common Practical Problems
Common problems in practice are:
O Unclear early local signs (snake may be
non poisonous).
O Atypical shape of the bite.
O Small amount of venom was injected with
no clear systemic signs.
O Atypical history.
How to deal with these cases????????

22. III. The Anti Snake Venom
(ASV)
Is not a safe routine line of management

23. Administration of ASV
How to give anti snake venom?

24. Polyvalent Versus Monovalent ASV
Polyvalent ASV
Advantages
Ø No need to identify
the type of the
snake
Ø Less expensive
Disadvantages
Ø Higher incidence of
allergic reactions

25. Monovalent ASV
Advantages
Ø Lower incidence of
allergic reactions.
Disadvantages
Ø Needs
identification of
snake type.
Ø More expensive.

26. Administration of ASV
Two methods of administration are recommended:
1. Intravenous infusion over one hour.
2. Intravenous injection (not commonly used).
Other methods: Not recommended and Not
effective:
O Local administration : extremely painful and may
increase intracompartmental pressure.
O Intramuscular injection: ASV have poor
bioavailability and blood levels never reach the
desired level. It is Severely painful with risk of
hematoma formation.

27. Dose of ASV
OAccording to WHO guidelines, initial dose
of ASV 100 ml is recommended.
OThe average dose ranges from 5-15 vials.

28. When to repeat the ASV?????
The patient should be observed for:
O Spontaneous systemic bleeding and blood
coagulability (20WBCT).
O Neurological or cardiovascular symptoms.
According to WHO ASV is repeated in cases of:
Ø Uncoagulability after 6 hours (20WBCT).
Ø Persistence or recurrence of bleeding after 1-2
hours.
Ø Progress of neurotoxic or cardiovascular signs
after 1-2 hours.

29. Reactions to ASV
Ø Early anaphylactic reactions (10 – 180 minutes).
Ø Pyrogenic ( endotoxic) reactions (1-2 hours).
Ø Late (serum sickness) reactions (1-12 days
average 7 days).
 Risk of reactions is ASV dose-related, except if
the victim has been sensitized e.g. to equine anti
venom or rabies-immune globulin.
 These reactions may be fatal but fatalities are
under-reported because deaths were attributed to
the venom (while patients may not be monitored
carefully after treatment).

30. How To Prevent ASV Reactions?
Clinical evidences recommend:
O During administration insert second line and
prepare anti anaphylactic measures.
O Slow injection and dilution of ASV.
O Careful observation during administration and
for 2 hours after the end of infusion (for early
and endotoxic reactions).
O Follow up for 7 days for late systemic reactions.

31. Common Clinical Problem
O Atypical history of unknown bite.
O Atypical shape of the bite.
O Minimum signs and /or symptoms within less
than one hour.
The question is
Give ASV immediately?
Observe the case?

32. There are three schools
First school:
O Give ASV immediately to all cases.
Second schools:
O Give ASV immediately to symptomatic
cases and observe suspicious cases.
Third school:
O Observe suspicious cases.
O Giving immediate ASV needs certain
indications.

33. According to third school:
Absolute clinical indications:
(Sure sings of considerable envenomation)
Viper bite Elapidae bite
O Progressive local signs.
O Spontaneous bleeding.
O Hypotension, shock or
cardio toxicity.
O Oliguria or anuria.
O Rhabdomyolysis.
O Passage of dark urine.
O Any neurotoxicity(specially
cranial nerve affection).
O Early weakness and
dyspnea.
O Progressive local
numbness.
O Hypotension , shock or
cardio toxicity.

34. Absolute laboratory indications: (sure
signs of considerable envenomation):
Viper bite Elapidae bite
Ø INR>1.3.
Ø Prolonged PT.
Ø Thrombocytopenia.
Ø Elevated urea and
creatinine
Ø Hyperkalemia.
Ø Metabolic acidosis.
O ECG changes.
O Respiratory acidosis.

35. Finally what to do???
Give or not to give ASV?
O These cases are either non poisonous cases or
very minimum amount of venom was injected.
O They are relative indications for ASV.
O According to first and second schools you
should administer the ASV.

36. According to third school:
Decision depends on:
O Your clinical evaluation.
O Availability of close monitoring and
observation (for immediate intervention).
O Availability of management of all possible
complication.
If you choose the third school consider very
close observation and monitoring for 24
hours and ability of rapid interference.

37. Remember
Ø Be quit fast, be quit calm.
Ø Pressure immobilization technique.
Ø Don’t leave the victim during and after
administration of ASV as its reactions may be
fatal.

38. See You Next Session