====== Summary points: ====== ===== STEP 1: Initial assessments, resuscitation and management ===== ABC (Airway, Breathing and Circulation)\\ Respiratory rate\\ Tidal volume\\ Ability to count for one breath( if a respirometer is not available )\\ Cyanosis\\ Neck muscle power **Clinical situations which need urgent resuscitation** \\ Respiratory muscle paralysis producing poor respiratory effort\\ Cardiovascular collapse and profound hypotension.\\ Comatose or semi comatose state and aspiration of vomitus\\ Profound bleeding ( haemoptisis, haematemesis )\\ Cardiac arrhythmias\\ Management\\ Intubation and Ambu ventilation (in impending respiratory paralysis)\\ Oxygen\\ Establish an intravenous line\\ Cardiac monitoring\\ Inotropics and anti-arrhythmic treatment\\ Left lateral position to prevent aspiration\\ Transfer with a doctor (if decided to transfer from a peripheral hospital) ===== STEP 2: Look for evidence of envenoming (to decide antivenom treatment) ===== Neurotoxicity – double vision, ptosis, ophthalmoplegia, altered consciousness )\\ Haematotoxicity- positiveWBCT20, haematuria, haematamesis, haemolysis\\ Local effects – fang marks, pain, swelling, discolouration\\ Nephrotoxicity – oliguria, rising blood urea and creatinine\\ Cardiac effects – chest pain, hypotension, ECG\\ Myotoxicity – muscle pain\\ Abdominal pain, vomiting (in krait bite) **How to do WBCT20 test** \\ Take a small clean glass test tube\\ Place a 2ml of freshly sampled venous blood\\ Tip the tube once to achieve surface contact\\ Leave undisturbed for 20 min at room temperature\\ Observe at 5min intervals for clot formation\\ If blood is unclotted and runs out at 20 min, the patient has positive test or\\ hypofibrinogenaemia as a result of consumption coagulopathy. If there is any doubt, repeat the test with a control (healthy person). It is important that the vessel used should be a cleaned glass test tube and small bottles shouldn’t be used as it may give false positive results. This test should be repeated at 1h, 2h, 6h and 12hour after admission for detection of the earliest sign of envenoming. This is important only in Russell’s viper bite. **Indications for antivenom** \\ Bleeding and clotting disorder ( Positive WBCT20, spontaneous bleeding)\\ Intravascular haemolysis(dark urine – dipstick test for haemoglobinuria)\\ Neutotoxic signs\\ Cardiovascular manifestations: hypotension, arrhythmia, abnormal ECG\\ Nephrotoxicity: oliguria, rising blood urea\\ Rhabdomyolysis( muscle pain, hyperkalaemia, myoglobinuria)\\ Local swelling( consider extent, rapid extension and degree of tissue damage)\\ All proven Russell’s viper bite (even before development of signs of envenoming. Fang marks and identification of offending snake are important). ===== STEP 3: Identify the offending snake (dead specimen, matches with preserved specimens, clinical evidence, circumstantial evidence) ===== Study the physical features of deadly venomous snakes responsible for the bite. Seek advice from experts ( SLMA committee on snake bite, Tel: 011 2693324 or from the nearest Medical Faculty) ===== STEP 4: Antivenom ( Indian polyvalent antivenom made against cobra, Russell’s viper, common krait and saw scaled viper). ===== Administer of the earliest evidence of envenoming\\ Not effective in hump-nosed viper bites\\ Give to all proven Russell’s viper bites if the fang marks and local swelling are present without waiting for evidence of systemic envenoming\\ Administer initial dose 10 vials,20 vials or 30vials depending on the severity of envenoming. Infusion should be started slowly at the beginning in order to detect allergic reactions and be completed in one hour.\\ Same dosage should be given to children, but volume of infusion can be decided to suite the body weight.\\ Repeat WBCT20 six(6) hourly in Russell’s viper bite to decide the second dose. ===== STEP 5: Prevention of antivenom reactions ===== Start a parallel infusion of hydrocortisone( 500 – 1000mg ) in 300ml of\\ normal saline 5 min before antivenom infusion and continue for 30 min\\ thereafter. May give hydrocortisone bolus(400mg) to begin with.\\ Give chlorpheniramine 10 mg iv bolus 5min after starting antivenom\\ Adrenaline sc(exclude contraindications)-0.25ml(1:1000) could be used\\ as prophylaxis, but carries a high risk of complications. ===== Step 6: Management of allergic reactions to antivenom ===== Stop antivenom infusion temporary until the reactions are treated. Severity of reactions could vary from mild to severe. Mild reactions include itching, urticaria, rigor with normal blood pressure. But hypotension occurs in moderate to severe reactions. Mild reactions: chlorpheniramine 10mg iv bolus\\ Moderate reactions: Adrenaline(1:1000 )0.5ml sc and chlorpheniramine\\ 10mg iv bolus\\ Severe reactions: Adrenaline(1:1000 )0.5ml im and chlorpheniramine\\ 10mg iv bolus Continue antivenom thereafter irrespective of reactions for 1h\\ Incidence of reactions comes down for 2nd of 3rd dose of antivenom ===== STEP 7: Supportive management ===== Paracetamol for pain , avoid NSAIDs such as aspirin\\ Fluids – avoid oral fluids for 24 hours in envenomed patients, however, adequate intravenous hydration is needed to prevent pre-renal failure.\\ Avoid – potassium containing foods\\ Oxygen via mask SOS\\ Antibiotics – unnecessary ( for local swelling )\\ Reassurance – allow a family member to stay with patient ===== STEP 8: Further monitoring ( to detect complications, assess recovery, treatments) ===== Urine output (normal 40-50ml/ hour )\\ Colour of the urine (haematuria, haemoglobinuria, myoglobinuria)\\ Fluid input ( avoid both over hydration and dehydration, in acute renal failure give fluid amount equal to insensible loss + urine output )\\ Respiration (respiratory rate / half hourly)\\ Tidal volume or one breath count (to detect respiratory paralysis)\\ Cyanosis ( blood gases if available ) to detect respiratory problems\\ Pulse- BP\\ Level of consciousness (LOC)\\ Bleeding and clotting time monitoring (WBCT20). Antivenom should be repeated until WBCT20 become normal for 24hours ===== Step 9: Anticipation and detection of complications ( important parameters) ===== Respiratory paralysis – tidal volume, respiratory rate, neck muscle power, hypoxia\\ Severe coagulopathy(DIC) – Persistently positive WBCT20, bleeding from venepuncture sites, low platelet count, FDP\\ Hyperkalaemia – serum electrolytes, ECG ( tall peak T wave, wide QRS)\\ Acute renal failure – oliguria, blood urea, serum creatinine\\ Shock – hypotension, tachycardia, cold peripheries\\ ARDS – blood gases ( hypoxaemia,hypercapnoea), Chest X- ray\\ Severe local effects – pain, discolouration, necrosis, fever\\ Compartment syndrome – loss of sensation in the digits, ischaemia, gangrene, pain and swelling. ===== STEP 10: Management of complications ===== Respiratory paralysis – Ambu ventilation, assisted ventilation\\ DIC – High dose antivenom, management of multiple organ damage, FFP, platelets\\ Hyperkalaemia – 10% calcium gluconate 10ml iv, Insulin/dextrose,\\ 1.26% NaHCO3 iv 50-100 ml, dialysis.\\ Acute renal failure – conservative management, dialysis\\ Shock- dopamine/ dobutamine\\ ARDS – IPPV with PEEP, Oxygen 80 –100%\\ Severe local effects – surgical debridement, antibiotics, skin graft\\ \\ Compartment syndrome – fasciotomy after haemostasis ===== Step 11: Management of long term sequels and rehabilitation ===== Contractures - physiotherapy\\ Neuropathy - reversible ===== Problem shooting during transfer and management ===== 1. Respiratory paralysis\\ 2. Pneumothorax due to forceful Ambu ventilation.\\ 3. Intubation of right bronchus and collapse of left lung:\\ 4. Allergic reactions to antivenom\\ 5. Aspiration of vomitus * [[:wikitox:sri_lankan_snakes|Home]] * [[:wikitox:handbook_snakes_introduction|Snakes - Introduction]] * [[:wikitox:handbook_venomous_snakes_of_sri_lanka|Venomous snakes of Sri Lanka]] * [[:wikitox:handbook_snake_venom|Snake venom]] * [[:wikitox:handbook_medically_important_snakes_of_sri_lanka|Medically important snakes of Sri Lanka]] * [[:wikitox:handbook_identification_and_morphological_characteristics|Identification and morphological characteristics]] * [[:wikitox:handbook_epidemiology_and_clinical_manifestations|Epidemiology and clinical manifestations]] * [[:wikitox:handbook_first_aid|First aid]] * [[:wikitox:handbook_management_at_a_peripheral_hospital|Management at a peripheral hospital]] * [[:wikitox:handbook_management_of_snake_bite_in_a_tertiary_care_hospital|Management of snake bite in a tertiary care hospital]] * [[:wikitox:handbook_special_situations_children_elderly_pregnancy_underlying_diseases|Special situations (children, elderly, pregnancy and underlying diseases)]] * [[:wikitox:handbook_health_education_on_the_prevention_of_snake_bite|Health education on the prevention of snake bite]] * [[:wikitox:handbook_summary|Summary]] (management in brief) * [[:wikitox:handbook_reference|Reference]]