snake envenomation causes headache, a thick feeling of the tongue, thirst, sweating and vomiting
KEEP FIRST AID MEASURES IN PLACE. If it’s not PUT IN ON!
Venoms are complex proteins with complex multisystem effects including:
· Neurotoxins (pre-& post-synaptic paralysis-esp. Tiger Snakes),
· Coagulant & hemolytic effects (clotting & bleeding disorders),
· Myotoxicity (rhabdomyolosis & renal failure)
· Local pain & bleeding at site, local lymphangitis & lymphadenopathy,
· Non-specific symptoms (nausea, vomiting, headache, abdominal pain) progressing to
· Neuromuscular sysmptoms with ptosis (important early sign), cranial nerve palsies (especially dysarthria & diplopia), generalized weaknzed, paralysis with respiratory failure & convulsions,
· Hemorrhage from anywhere (may be massive!),
Myotoxicity presents with muscle pains, myoglobinuria & rising CK.
1. Involve Medical Officer & senior staff early. Early aggressive intervention is the key to success
3. IV access x2,
5. Consider catheterisation if unwell with hourly output measurement,
6. FBC, U&E’s, LFT’s, CK, Coagulation Profile, Serum fibrinogen, FDP’s Group & Retain, urinalysis,
7. Venom Detection Kit (VDK) using (preferably) bite site swab or urine – a positive test indicates TYPE of anti-venom that might be needed NOT whether its use is indicated,
8. AFTER pathology & VDK results results are back & you have secured IV access remove First Aid,
9. Monitor ¼ hourly for 1 hour, ½ hourly for 4 hours & then hourly for 24 hours then 4 hourly afterwards.
If clinically well & No Abnormality Discovered (including negative VDK) – observe as above & repeat path after 4 hours.
A positive VDK or minor symptoms (Headache, Nausea, Vomiting, Abdominal pain) ARE NOT INDICATIONS FOR ANTI-VENOM.
If signs of clinically significant envenomation commence treatment with appropriate anti-venom as below.
Clinically significant signs include:
· Developing paralysis or development of ptosis,
· Developing coagulopathy,
· Developing renal failure,
· Collapse or convulsion,
· Developing Myolysis.
Administer polyvalent antivenom if situation prevents full VDK identification.
· Consider premedication with Adrenaline 0.25mls 1:1000 S/C & 0.25mls 1:000 IV over 3 minutes & Phenergan 1mg/kg IV (up to 50mg) & Hydrocortisone 100mg IV IF known horse serum allergy or previous exposure/ know allergy to snake anti-venom,
· For Tiger/Copperhead or Black Snake bites use Tiger Anti-venom, for Brown snake use Brown snake anti-venom,
· Dilute in 250ml N.Saline & infuse IV over 15-30 minutes,
· If anaphylaxis occurs, stop infusion, resuscitate & treat & consider recommencing anti-venom cautiously,
· Anti-venom takes 2-3 hours to be fully effective,
· Check path after 2-3 hours,
· If clinically or pathologically no better or worse at this time give more anti-venom.
ADMIT anyone for minimum period of 24 hours observation that in a 4-hour period has had any one of:
· Symptoms (even minor) or
· A positive urinary VDK or
· Abnormal pathology or
· Who has required anti-venom.
Anyone receiving anti-venom should generally receive Prednisolone 50mg daily for 1/52 as prophylaxis against “serum sickness”.
Avoid IM injections (Including ADT) until after any coagulopathy has ceased to be significant.