SNAKE BITE
SNAKE BITE:----Snake venom may contain twenty or more toxins. Most of them are enzymes, non-enzyme peptide toxins and non-toxic proteins. The cobra and krait venoms are neurotoxic and cardiotoxic. Local effects are seen in the former but not in the latter. Viper venom is vasculotoxic and has severe necrotizing local effects. The neurotoxins of elapids and sea snakes are absorbed rapidly into the blood stream (therefore causing rapid systemic effects), whereas the much larger molecules of viper venom are taken up more slowly through the lymphatics (therefore causing severe local effects). Most venoms do not cross blood brain barrier CLINICAL FEATURES OF SNAKEBITE:- Fangmarks,Pain, Local swelling Local necrosis,Secondary infection. SYSTEMIC FEATURES:-Neurotoxicity,Myotoxicity,Cardiotoxicity,Nephrotoxicity, shock, Management of snake bite First aid: The patient should be reassured and moved to the nearest hospital as quickly as possible. Active movements should be as minimal as possible. The bitten part should be immobilized with a splint or sling. Tourniquets and compression bandages are potentially dangerous as they can cause gangrene, increased fibrinolysis and bleeding in the occluded limb, peripheral nerve palsies and intensification of local envenomation. The only indication for their use is in case of severe elapid or sea snake bites where the delay in reaching a medical centre is likely to be more than 0.5 hours but less than 2-3 hours. Here compression / tourniquet delay absorption of the venom and so help retard onset of respiratory muscle paralysis.Tourniquet should be tight enough to occlude the lymphatic and venous flow but not the arterial flow. A useful guide is that it should be loose enough to permit a finger to slip under it. The tourniquet should be released for 30 seconds every 15 minutes to allow slow release of venom into circulation, thereby enabling its neutralization. The tourniquet should only be released after the first dose of antivenom is given.The bite wound should be gently wiped with sterile cotton gauze.In case of incoagulable blood or oozing from puncture wounds only use the intravenous route for meditation.