3 - Envenomation - Snakes - Specific Management.pdf

21/09/2022 Envenomation – Snakes Specific Management •1 Locate & Review • The lymphatic system & its function • Review the nervous system, especially the neuromuscular junction • Review the clotting cascade • Review relevant articles •2 PRESSURE IMMOBILISATION BANDAGE (PIB) •3 1 21/09/2022...

21/09/2022 Envenomation – Snakes Specific Management •1 Locate & Review • The lymphatic system & its function • Review the nervous system, especially the neuromuscular junction • Review the clotting cascade • Review relevant articles •2 PRESSURE IMMOBILISATION BANDAGE (PIB) •3 1 21/09/2022 Pressure Immobilisation Bandage (PIB) • Before applying a bandage make a note of the bite site • Try to mark bite site on bandage • Do not wash or wipe bite site before PIB application • Apply bandages as firmly as you would to a sprained ankle • Start at or below the bite and wrap upwards • Apply as far as possible up limb to compress lymphatic vessels • Apply a splint to the limb to restrict movement • Keep limb and person as still as possible • If bitten on trunk, neck or head, apply firm pressure to bitten area •4 •5 ANTIVENOM •6 2 21/09/2022 Making Antivenom •7 Antivenoms • Purified antibodies obtained from animals immunised against the venom (ie. animal ‘Blood Bank’), Usually horses (chicken eggs?) •8 Types of Antivenom • Monovalent antivenom – Raised against the venom of one species • Polyvalent antivenom – A combination of all species used – Australian polyvalent AV contains Brown snake, Tiger snake, King Brown snake, Death Adder and Taipan antivenoms •9 3 21/09/2022 How much Antivenom? • How much antivenom is in a vial? – Measured in “units” – 1 unit should neutralise 0.01mg of dried venom – Each vial has enough to neutralise an average venom yield from that species • • • • • • • Sea snake ‐ 1,000 units Brown snake ‐ 1,000 units Tiger snake ‐ 3,000 units Death Adder ‐ 6,000 units Taipan – 12,000 units Black snake – 18,000 units Polyvalent – 40,000 units (does not have sea snake) • One vial has been given… still see symptoms => Give another one?? •10 Complications of Antivenom Use • Antivenoms are foreign proteins being injected & hence may result in allergic reactions such as rash or as severe as anaphylactic shock • If given in excess, it may block the receptor site so neurotransmitter can’t bind – develop symptoms similar to snake bite •11 Any Questions •12 4