snake bite management 1

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SNAKE BITE MANAGEMENT DR.S.SREENIVASARAO MD,C.C.P.P.M, ASSIST PROFESSOR, DEPT.OF ANAESTHESIA, S.V.R.R.G.G.H.&S.V.M.C, TIRUPATI

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CLASSIFICATION OF SNAKES Elapidae cobras,king cobra, kraits, coral snakes and the sea snakes. Viperidae two subgroups, the typical vipers ( Viperinae ) the pit vipers ( Crotalinae ). Short, permanently erect, fangs of a typical elapid (Thai monocellate cobra – Naja kaouthia ) ) Russell’s vipers details of fangs

What happens if snake bites???:

What happens if snake bites???

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GENERAL S& S OF VIPERINE ENVENOMATION Swelling and local pain . Tender enlargement of local lymph nodes as larg MW Viper venom molecules enter the system via the lymphatics . Bleeding from the gingival sulci & other orifices Epistaxis . Vomiting ( Kalantri SP et al. 2006). Acute abdominal tenderness which may sugget GI or retroperitoneal bleeding. Hypotension resulting from hypovolaemia or direct vasodilation .

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Low back pain , indicative of a early renal failure or retroperitoneal bleeding , although this must be carefully investigated as many rural workers involved in picking activities complain of back pain generally. The skin & mucous membranes may show evidence of petechiae,purpura ecchymoses The passing of reddish or dark-brown urine or declining or no urine output Lateralising neurological symptoms & asymmetrical pupils may be indicative of intra-cranial bleeding. Muscle pain indicating rhabdomyolysis Parotid swelling,conjuntival oedema,sub-conjunctival haemorrhage

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GENERAL S&S OF ELAPID ENVENOMATION Swelling and local pain (Cobra). Local necrosis and/or blistering (Cobra) . Descending paralysis, initially of muscles innervated by the cranial nerves, commencing with ptosis, diplopia , or ophthalmoplegia . The patient complain difficulty in focusing and the eyelids feel heavy. There may be some involvement of the senses of taste and smell but these need further research. Paralysis of jaw and tongue may lead to upper airway obstruction and aspiration of pooled secretions because of the patient’s inability to swallow.

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Numbness around the lips and mouth, progressing to pooling of secretions, bulbar paralysis and respiratory failure. Hypoxia due to inadequate ventilation can cause cyanosis, altered sensorium &coma-needs urgent intervention Paradoxical respiration, as a result of the intercostal muscles becoming paralysed is a frequent sign Stomach pain which may sugget submucosal haemorrhages in the stomach ( Kularatne 2002)(krait) Krait bites often present in the early morning with paralysis that can be mistaken for a stroke

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Broken neck sign in a child envenomed by a cobra in Malaysia Inability to open the mouth and protrude the tongue in a patient with neurotoxic envenoming from the Malayan krait

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Long term complications ( sequelae ) of snake bite Chronic physical handicap resulting from necrotic envenoming by Malayan pit vipers Squamous cell carcinoma developing at the site of a chronic skin ulcer with osteomyelitis 8years after a bite by a Malayan pit viper Patient bitten by a Burmese Russell’s viper three years previously, showing clinical signs of panhypopituitarism : loss of secondary sexual hair and testicular atrophy

Algorithm for diagnosis of the snake responsible for a bite in Sri Lanka (Ariaratnam et al., 2009):

Algorithm for diagnosis of the snake responsible for a bite in Sri Lanka (Ariaratnam et al., 2009)

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First Aid Treatment Protocol “Do it R.I.G.H.T.” R. = Reassure the patient. 70% of all snakebites are from non- venomous species. Only 50% of bites by venomous species actually envenomate the patient I = Immobilise in the same way as a fractured limb. Use bandages or cloth to hold the splints, not to block the blood supply or apply pressure. Do not apply any compression in the form of tight ligatures, they don’t work and can be dangerous! G. H. = Get to Hospital Immediately. Traditional remedies have NO PROVEN benefit in treating snakebite. T= Tell the doctor of any systemic symptoms such as ptosis that manifest on the way to hospital.

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Traditional Methods to Be Discarded Tourniquets Risk of Ischemia and loss of the limb (Warrell, 1999). Increased Risk of Necrosis with 4/5 of the medically significant snakes of India. (Fairly, 1929) (Pugh et al, 1987) (Warrell, 1995). Increased risk of massive neurotoxic blockade when tourniquet is released (Watt, 1988) Risk of embolism if used in viper bites. Pro-coagulant enzymes will cause clotting in distal blood. In addition, the effect of the venom in causing vasodilatation presents the danger of massive hypotension when the tourniquet is released. They do not work! (Tun Pe 1987) (Khin-Ohn Lwin 1984).

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Traditional Methods to Be Discarded Venom was not slowed by the tourniquet in several experimental studies, as well as in field conditions. Often this is because they are tied on the lower limb are incorrectly tied (Watt, 2003) (Amaral, 1998) (Nishioka, 2000). They give patients a false sense of security, which encourages them to delay their journey to hospital. For the above reasons, Tourniquet use is contra-indicated for use in India

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Traditional Methods to Be Discarded Cutting and Suction Cutting a victim with incoagulable blood increases the risk of severe bleeding as the clotting mechanism is no longer effective and increases the risk of infection. No venom is removed by this method. Suction devices have been conclusively proven not to reduce the amount of circulating venom (Bush, 2000) (Bush, 2004). There has been some evidence that these devices increase envenomation as they inhibit natural oozing of venom from the wound (Alberts et al, 2004). In addition, they have been shown to increase the local effects of necrosis (Alberts et al, 2004).

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Traditional Methods to Be Discarded Washing the Wound Victims and bystanders often want to wash the wound to remove any venom on the surface. This should not be done as the action of washing increases the flow of venom into the system by stimulating the lymphatic system (Gray, 2003).

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Further First Aid Research Research that has suggested that a ‘Pressure Pad or MonashTechnique’ may have some benefit in the first aid treatment of snakebite (Anker et al, 1982) (Ton Pe et al, 1995) (Tun Pe et al, 2000). In this method a hard pad of rubber or cloth is applied directly to the wound in an attempt to reduce venom entering the system Pressure immobilisation is recommended for bites by neurotoxic elapid snakes, including sea snakes but should not be used for viper bites because of the danger of increasing the local effects of the necrotic venom.

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Snake Bite Treatment Protocol

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Management of snake bite First aid treatment Transport to hospital Rapid clinical assessment and resuscitation Detailed clinical assessment and species diagnosis Investigations/laboratory tests Antivenom treatment Observation of the response to antivenom : decision about the need for further dose(s) of antivenom Supportive/ancillary treatment Treatment of the bitten part Rehabilitation Treatment of chronic complications

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Patient Assessment Phase: On arrival Deal with any life threatening symptoms on presentation. i.e. Airway, Breathing and Circulation. If there is evidence of a bite, where the skin has been broken, give Tetanus Toxoid Routine use of anti-biotic is not necessary, although it should be considered if there is evidence of cellulitis or necrosis .

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Diagnosis Phase: General Principles Where possible identify the snake responsible( pupil shape and scalation). Have the victim carefully bring the snake to hospital if it has been killed. All patients will be kept under observation for a minimum of 24 hours. In some countries bite marks have limited use in determining species (Nishioka et al, 1995) (Norris, 1995) . Many non venomous species leave just two fang-like marks e.g. Wolf Snakes. Some species like the Krait may leave no bite mark at all. Many venomous species have more than two fangs, as they grow reserve fangs in case the main ones break off.

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Diagnosis Phase: General Principles Determine if any traditional medicines have been used, they can sometimes cause confusing symptoms. Determine the exact time of the bite. This can give indications as to the progression of any symptoms. Ask questions as to what the victim was doing at the time of the bite. Some activities such as grass cutting or feeding stock animals in the evening can be suggestive of snakebite.

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Pain Snakebite can often cause severe pain at the bite site, can be treated with painkillers such as paracetamol Adult dose of 500-1000mg 4-6 hourly. Pediatric dose 10mg/kg every 4-6 hourly orally Mild opiates such as Tramadol, 50 mg can be used orally for relief of severe pain. In cases of severe pain at a tertiary centre, Tramadol can be given IV. Aspirin should not be used due to its adverse impact on coagulation Do not use non steroidal anti-inflammatory drugs (NSAIDs) as they can cause bleeding, can be particularly dangerous in a patient already having coagulopathy

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Handling Tourniquets Care must be taken when removing tight tourniquets tied by the victim. Sudden removal can lead to a massive surge of venom leading to neurological paralysis, hypotension due to vasodilatation etc. Before removal of the tourniquet, test for the presence of a pulse distal to the tourniquet. If the pulse is absent ensure a doctor is present before removal. Be prepared to handle the complications such as sudden respiratory distress or hypotension If the tourniquet has occluded the distal pulse, then a blood pressure cuff can be applied to reduce the pressure slowly.

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Diagnosis Phase: Investigations 20 Minute Whole Blood Clotting Test (20WBCT) most reliable test of coagulation and can be carried out at the bedside without specialist training A few mls of fresh venous blood is placed in a new, clean and dry glass test tube and left at ambient temperature for 20 minutes. It is important that the tube is clean, glass and dry as the mechanism under review is the contact clotting mechanism The glass vessel should be left undisturbed for 20 minutes and then gently tilted, not shaken. If the blood is still liquid then the patient has incoagulable blood. The vessel must not have been washed with detergent as this will inhibit the contact element of the clotting mechanism. The test should be carried out every 30 minutes from admission for three hours and then hourly after that. If incoagulable blood is discovered, the 6 hourly cycle will then be adopted to test for the requirement for repeat doses of ASV.

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Tests depending on availability Hemoglobin/ PCV/ Platelet Count/ PT/ APTT/ FDP/ D-Dimer Peripheral Smear Urine Tests for Proteinuria/ RBC/ Haemoglobinuria/ Myoglobinuria Biochemistry for Serum Creatinine / Urea/ Potassium Oxygen Saturation/ PR/BP/ RR/ Postural Blood Pressure ECG/ X-Ray/ CT/ Ultrasound (The use of X-Ray and ultrasound are of unproven benefit, apart from identification of bleeding in Viperine bites

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Diagnosis Phase: Symptoms FEATURE COBRAS KRAITS RUSSELS VIPER SAW SCALED VIPER HUMP NOSED VIPER LOCAL PAIN/TISSUE DAMAGE YES NO YES YES YES PTOSIS/NEUROLOGICAL SIGNS YES YES YES! NO NO HAEMOSTATIC ABNORMALITIES NO NO! YES YES YES RENAL COMPLICATIONS NO NO YES NO YES RESPONSE TO NEOSTIGMINE YES NO? NO? NO NO RESPONSE TO ASV YES YES YES YES NO

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Table 3: Assessment of severity of envenomation No envenomation Absence of local or systemic reactions, Fang marks +/- Mild envenomation Fang marks (, moderate pain, minimal local oedema (0-15cms), erythema+, ecchymosis +/-, no systemic reactions Moderate envenomation Fang marks+, severe pain, moderate local edema (15-30cms), erythema & ecchymosis +, systemic weakness, sweating, syncope, nausea, vomiting, anemia or thrombocytopenia Severe envenomation Fang marks+, severe pain, severe local edema (>30cms), erythema & ecchymosis +, hypotension, parasthesia , coma, pulmonary edema, respiratory failure Phosphomesteras Minimal Heavy Unknown Phosphomesteras Minimal Heavy UnknownAnti venom therapy No envenomation --Absence of local or systemic reactions, Fang marks +/- Mild envenomation --Fang marks (, moderate pain, minimal local oedema (0-15cms), erythema +, ecchymosis +/-, no systemic reactions Moderate envenomation --Fang marks+, severe pain, moderate local edema (15-30cms), erythema & ecchymosis +, systemic weakness, sweating, syncope, nausea, vomiting, anemia or thrombocytopenia Severe envenomation --Fang marks+, severe pain, severe local edema (>30cms), erythema & ecchymosis +, hypotension, parasthesia , coma, pulmonary edema, respiratory failure Assessment of severity of envenomation

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Late-onset envenoming The patient should be kept under close observation for at leat 24 hours. Many species, particularly the Krait and the Hump-nosed pitviper (Joseph et al, 2006) are known for the length of time it can take for symptoms to manifest,often this can take between 6-12 hours Late onset envenoming is a well documented occurrence (Ho et al, 1986) ( Warrelet al, 1977) (Reitz, 1989).

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Late-onset envenoming ??? This is also particularly pertinent at the start of the rainy season when snakes generally give birth to their young Juvenile snakes,8-10 inch long, tend to bite the victim lower down on the foot in the hard tissue area,and thus any signs of envenomation can take much longer time to appear

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Anti Snake Venom (ASV) Anti snake venom (ASV) in India is polyvalent i.e. it is effective against all the four common species; Russells viper ( Daboia russelii ), Common Cobra ( Naja naja ), Common Krait ( Bungarus caeruleus ) and Saw Scaled viper ( Echis carinatus ) ASV is produced in both liquid and lyophilised forms Liquid ASV requires a reliable cold chain& refrigeration and has a 2year shelf life. Lyophilised ASV, in powder form, requires only to be kept cool. This is a useful feature in remote areas where power supply is inconsistent.

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ASV Administration Criteria should only be administered when there are definite signs of envenomation Unbound, free flowing venom can only be neutralised when it is in the bloodstream/tissue fluid Should not be used unnecessarily— --Severe anaphylactic reactions --Very costly

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SYSTEMIC ENVENOMING Evidence of coagulopathy: Primarily detected by 20WBCT or visible spontaneous systemic bleeding, gums etc. Further laboratory tests for thrombocytopenia, Hb abnormalities, PCV, peripheral smear etc provide confirmation, but 20WBCT is paramount. Evidence of neurotoxicity: ptosis, external ophthalmoplegia , muscle paralysis inability to lift the head etc. CVS abnormalities: hypotension, shock,cardiac arrhythmia abnormal ECG. Persistent and severe vomiting or abdominal pain.

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SEVERE CURRENT LOCAL ENVENOMING Severe current, local swelling involving more than half of the bitten limb (in the absence of a tourniquet). In the case of severe swelling after bites on the digits(toes and especially fingers) after a bite from a known necrotic species Rapid extension of swelling( EX.beyond the wrist or ankle with in a few hours of bites on the hands or feet). Swelling continues after one hour of removing the tourniquet ,ASV may be applicable Swelling a number of hours old is not grounds for giving ASV.

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Antivenom reactions Early anaphylactic reactions: usually within 10-180 minutes of starting antivenom , the patient begins to itch (often over the scalp) and develops urticaria , dry cough, fever, nausea, vomiting, abdominal colic, diarrhoea and tachycardia. A minority of these patients may develop severe life-threatening anaphylaxis: hypotension, bronchospasm and angio-oedema . Fatal reactions have probably been under-reported as death after snake bite is usually attributed to the venom.

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Antivenom reactions Pyrogenic ( endotoxin ) reactions usually develop 1-2 hours after treatment. Symptoms include shaking chills (rigors), fever, vasodilatation and a fall in bloodpressure . Febrile convulsions may be precipitated in children. These reactions are caused by pyrogen contamination during the manufacturing process. .

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Antivenom reactions Late (serum sickness type) reactions develop 1-12 (mean 7) days after treatment. Clinical features include fever, nausea, vomiting, diarrhoea , itching, recurrent urticaria , arthralgia , myalgia , lymphadenopathy , periarticular swellings, mononeuritis multiplex, proteinuria with immune complex nephritis and rarely encephalopathy. Patients who suffer early reactions and are treated with antihistamines and corticosteroid are less likely to develop late reactions .

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ASV Reactions- prophylactc regimens Two regimens are recommended REGIMEN 1- 100 mg of Hydrocortisone & H1 antihistamine(10mg chlorphenimarine maleate /22.5mg IV Phenomarine maleate /25mg Promethazine HCL IM) 5 minutes before ASV administration In children 0.1-0.3mg/kg of antihistamine IV &2mg/kg hydrocortisone REGIMEN 2- 0.25-0.3mg adrenaline 1:1000 given subcutaneously KNOWN SENSITIVITY TO ASV PREMEDICATION WITH ADRENALINE,ANTIHISTAMINE,HYDROCORTISONE IS ADVISABLE

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Treatment of late (serum sickness) reactions Late (serum sickness) reactions usually respond to a 5-day course of oral antihistamine. Patients who fail to respond in 24-48 hours should be given a 5-day course of prednisolone . Doses: Chlorpheniramine : adults 2 mg six hourly, children 0.25 mg/kg /day in divided doses Prednisolone : adults 5 mg six hourly, children 0.7 mg/kg/day in divided doses for 5-7 days

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ASV Administration: Dosage Initial dose should be calculated to neutralise the average dose of venom injected The range of venom injected is 5mg—147mg Total required dose will be between 10 vials-25 vials & each vial neutralises 6mg of russels viper venom Low dose and high dose regimens are not practised in india

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ASV Administration: Dosage ASV is recommended to be administered in the fallowing intial dose Neurotoxic/ Anti Haemostatic………….. 8-10 Vials ASV can be administered in two ways 1.IV Injection: reconstituted or liquid ASV is administered by slow IV injection(2ml/ mt ) each vial is 10ml of recostituted ASV 2.Infusion: liquid or reconstituted ASV is diluted in in 5-10ml/kg bw of isotonic saline or glucose ALL ASV to be administered over 1 hour at constant speed

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LOCAL ASV ??? Local administration of ASV , Near bite side has been proven to be ineffective, Painfull , Raises the intracompartmental pressure particularly in the digits It should not be used

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ASV – PAEDIATRICS ? Children receive same ASV dosage as adults The ASV is targeted at neutralising the venom Snakes inject the same amount of venom into adults and children

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N0 ASV TEST DOSE MUST BE ADMINISTERED! Test dose have been shown to have no predictive value in detecting anaphylactoid or late serum reactions and should not be used( warrell et al 1999) These reactions are not IgE mediated but Compliment activated They may also pre-sensitise the patient and thereby create greater risk

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Victims Who Arrive Late A frequent problem is victims who arrive late after the bite, often after several days, usually with acute renal failure Should we administer ASV? The key determining factor is, are there any signs of current venom activity? Venom can only neutralized if is unattached ! Perform a 20WBCT & determine if any coagulopathy is present& give ASV if present NO coagulopathy is evident treat any renal failure by reference to a nephrologists & dialysis In case of neurotoxic symptoms like ptosis & resp. failure it is probably wise to administer 1 dose of 8-10 vials ASV to ensure that no unbound venom is present

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ASV Reactions Anaphylaxis is life-threatening Anaphylaxis can be rapid onset & rapidly deteriorate into a life threatening emergency The patient should be monitored closely (Peshin et al, 1997) and at the first sign of any of the following: Urticaria, itching, fever, shaking chills, nausea, vomiting, diarrhoea , abdominal cramps ,tachycardia, hypotension, bronchospasm & angio-oedema

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ASV Reactions 1. ASV IS DISCONTINUED 2. 0.5 mg of 1:1000 adrenaline will be given Children are given 0.01mg/kg BW of adrenaline IM IN addition to provide longer term protection against anaphylactoid reaction 100 mg of hydrocortisone & Phenimarine maleate at 0.5mg/kg/day IV / Promethasone HCL can be used at 0.3-0.5 mg/kg IM or 0.2 mg /kg of Chlorphenimarine Maleate IV & 2mg/ kgHydrocortisone IV

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ASV Reactions If after 10 to 15 minutes the patient's condition has not improved or is worsening, a second dose of 0.5 mg of adrenalin 1:1000 IM is given . This can be repeated for a third and final occasion but in the vast majority of cases 2 dose of Adernaline will be sufficient Once the patient has recovered ,the ASV can be restarted slowly for 10-15 minutes,keeping the patient under close observation Then the normal drip rate should be resumed

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ASV Reactions Late Serum sickness reactions can be easily treated with an oral steroid such as PREDNISOLONE Adults- 5mg 6 th hourly Pediatric dose –0.7mg/kg/day Oral H1 Antihistamines provide additional symptomatic relief

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Neurotoxic Envenomation Neostigmine is an anticholinesterase that prolongs the life of acetylcholine and can therefore reverse respiratory failure and neurotoxic symptoms. Particularly effective for post synaptic neurotoxin such as those of Cobra (Watt et ai,1986) Doubt over its usefullness against the pre-synaptic neurotoxin such as those of the Krait & russells Viper (Watt et ai,1986)

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NEOSTIGMINE TEST 1.5 -2.0 mg of Neostigmine IM,with 0.6mg of Atropine IV In paediatrics-0.04mg/kg IM&0.05mg/kg Atropine IV Pt should be closely observed for 1 hour to determine if the Neostigmine is effective objective methods to observe are -single breath count -Mm of Iris uncovered(Amount covered by the descending eyelid) -Inter incisor distance(Measured between upper & lower) Length of time upward gaze can be maintained -FEV1 or FVC(if available) For every 10 minutes the maesurement is repeated The average blood plasma time for Neostigmine is 20minutes so t+30 any improvement shuld be visible

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If the victim responds to the neostigmine test then continue with 0.5mg of neostigmine IM half hourly plus 0.6mg of Atropine IV over an 8 hour period by continuois infusion No improvement in symptoms after one hour ,the Neostigmine should be stopped (a) before and (b) after intravenous atropine followed by intravenous edrophoniumchloride in a patient envenomed by a Malayan krait ( Bungarus candidus

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Year : 2007 | Volume : 11 | Issue : 3 | Page : 161-164Neurotoxic snake bite with respiratory failure Anticholinesterase (i.e. neostigmine started at a rate of 25 mcg/kg/hour) and anticholinergic ( glycopyrolate ) combination as infusion to reverse the neuromuscular blockade till ptosis improved Year : 2007 | Volume : 11 | Issue : 3 | Page : 161-164Neurotoxic snake bite with respiratory failure

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Recovery Phase If an adequate dose of ASV has been administered, the fallowing responses may be seen Spontaneous systemic bleeding such as gum bleeding usually stops within 15-30minutes b) Blood coagulability is usually restored in 6 hours. Principle test is 20WBCT c) Post synaptic neurotoxic envenoming such as the Cobra may begin to improve as early as 30 minutes after antivenom , but can take several hours.

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Recovery Phase d) Presynaptic neurotoxic envenoming such as the Krait usually takes a considerable time to improve reflecting the need for the body to generate new ACH emitters e) Active haemolysis and rhabdomyolysis may cease within a few hours and the urine returns to its normal colour f) In shocked patients, blood pressure may increase after 30 minutes

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Repeat Doses: Anti Haemostatic In antihaemostatic envenomation the ASV will be based around a six hour time period When initial blood test reveals a coagulation abnormality, the initial ASV amount will be given over 1 hour No additional ASV will be given until the next clotting test is performed This is due to the inability of the liver to replace clotting factors in under 6 hours After 6 hours a further CT should be performed and a further dose should be administered in the event of continued coagulation disturbance & the dose should also be given over 1 hour CT test and repeat doses of ASV should continue on a 6 hourly pattern until coagulation is restored The repeat dose should be 5-10 vials of ASV i.e. half to one full dose of the original amount

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Recurrent Envenomation When coagulation has been restored no further ASV should be administered, unless a proven recurrence of a coagulation abnormality is established. There is no need to give prophylactic ASV to prevent recurrence( srimannarayana et al 2004) Recurrence has been a mainly U.S. phenomenon, due to the short half-life of Cro-fab ASV Indian ASV is a F( ab )2 product and has a half –life over 90 hours and therefore is not required in a prophylactic dose to prevent re- envenomation

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Repeat Doses: Neurotoxic If the initial dose has been unsuccessful in reducing the symptoms or if the symptom have worsened or if the patient has gone into respiratory failure then a further dose should be administered, after 1-2 hours At this point the patient should be re-assessed. If the symptoms have worsened or have not improved, a second dose of ASV should be given This dose should be the same as the initial dose, i.e. if 10 vials were given initially then 10 vials should be repeated for a second dose and then ASV is discontinued.

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20 vials is the maximum dose of ASV that should be given to a neurotoxically envenomed patient Once the patient is in respiratory failure, has received 20 vials of ASV and is support on a ventilator, ASV therapy should be stopped. This recommendation is due to the assumption that all circulating venom would have been neutrlised by this point Evidence suggests that ‘reversibility’ of post synaptic neurotoxic envenoming is only possible in the first few hours. After that the body recovers by using its own mechanisms Larger doses, over a long periods, have no benefit in reversing envenomation No further doses of ASV are required; unless a proven recurrence of envenomation is established, additional vials to prevent recurrence is not necessary

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Hypotension Due to loss of circulating volume due to hemorrhaging Vasodilatation due to the action of the venom or direct effect s on the heart Treatment is by means of plasma expanders In cases where generalized capillary permeability has been established a vasoconstrictor such as Dopamine can be used(5-10µ/kg/minute Russell's Viper bites are known to cause acute pituitary adrenal insufficiency ( Tun Pe et al, 1987) ( Eapen et al 1976). This condition may contribute to shock. Follow-up checks on known Russell's Viper victims need to ensure that no long term pituitary squeal are evident

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Surgical Intervention There is undoubtedly a place for a surgical debridement of necrotic tissue The appearance of (Joseph,2003) Pain on passive stretching Pain out of proportion Pulselessnes Pallor Parasthesia Paralysis with significant swelling in the limb, can lead to the conclusion that the intracompartmental pressure is above 40mmohg & thus requires a fasciotomy Fasciotomy does not remove or reduce any envenomation.

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Renal Failure and ASV Renal failure is a common complication of Russell's Viper& HP Viper(Tin-Nu- Swe et al1993,Joseph et al 2006) The contributory factors are( Chugh et al 1975) Intravascular heamolysis DIC Direct nephrotoxicity Hypotension Rhabdpmyolysis Renal damage develop very early in the case of Russell's bite & even when the pt arrives at hospital soon after the bite, the damage may already have been done Studies have shown that even when ASV is administered within 1-2hours after the bite, it was incapable of preventing ARF( Mytin-Lwin et al 1985)

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The following are indications of renal failure 1. Declining or no urine output although not all cases of RF exhibits oliguria(Anderson et a 1977) 2. Blood Testing • Serum Creatinine > 5mg/dl or rise of > 1mg / day. • Urea > 200mg/dl • Potassium > 5.6 mmol/l Confirm hyperkalaemia with EKG. 3. Evidence of Uraemia or metabolic acidosis. Declining renal parameters require referral to a specialist -nephrologist with access to dialysis equipment. Peritoneal dialysis could be performed in secondary care centres. Haemodialysis is preferable in cases of hypotension or hyperkalaemia .

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ASV Dosage in Victims Requiring Life Saving Surgery I n rare cases symptoms may develop which indicate that life saving surgery is required in order to save the victim Ex- signs of IC bleeding Before surgery ,coagulation must be restored to avoid catastrophic bleeding In such cases a higher initial dose of ASV is justified i.e. up to 25vials

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Snakebite in Pregnancy Recent literature shows fetal loss in pregnancy is 20% and it may be due to Fetal anoxia associated with maternal shock Direct effect of venom on fetus? Hemorrhage in to the placenta & uterine wall causing abruptio placenta Premature uterine contractions intiated by the venom Pyrexia & cytokine release after tissue damage Maternal hemorrhage with acute fetal anemia causing uterofetal death Supine hypotension syndrome Potential maternal anaphylaxis to antivenom

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Supportive/ancillary treatment Hypotension and shock Snake bite: causes of hypotension and shock (1) Anaphylaxis (2) Antivenom reaction Vasodilatation Respiratory failure Cardiotoxicity Acute pituitary adrenal insufficiency Hypovolaemia Septicaemia Oliguria and renal failure Detection of renal failure • Dwindling or no urine output • Rising blood urea/ creatinine concentrations • Clinical “ uraemia syndrome” nausea, vomiting, hiccups, fetor, drowsiness, confusion, coma, flapping tremor, muscle twitching, convulsions, pericardial friction rub, signs of fluid overload

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(1) Establish intravenous access (2) Insert a urethral catheter (full sterile precautions!) (3) Determine the central venous pressure.. (4) Fluid challenge (5) Furosamide ( frusemide ) challenge (6) Mannitol challenge (7) Conservative management (8) Biochemical monitoring (9) Dialysis Indications for dialysis • Clinical uraemia • Fluid overload • Blood biochemistry – one or more of the following creatinine >6 mg/dl (500 μ mol/l) urea >200 mg/dl (400 mmol /l) potassium >7 mmol /l (or hyperkalaemic ECG changes) symptomatic acidosis Treatment for Oliguric phase of renal failure

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Treatment of the bitten part Bacterial infections prophylactic course of penicillin (or erythromycin for penicillin-hypersensitive patients) and a single dose of gentamicin or a course of chloramphenicol , together with a booster dose of tetanus toxoid is recommended. the use of broad spectrum antibiotics ( eg amoxycillin or a cephalosporin plus a single dose of gentamicin plus metronidazole ). Compartmental syndromes and fasciotomy Clinical features of a compartmental syndrome • Disproportionately severe pain • Weakness of intracompartmental muscles • Pain on passive stretching of intracompartmental muscles • Hypoaesthesia of areas of skin supplied by nerves running through the compartment • Obvious tenseness of the compartment on palpation

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Conservative treatment when no antivenom is available Neurotoxic envenoming with respiratory paralysis: assisted ventilation. This has proved effective, and has been followed by complete recovery, even after being maintained for periods of more than one month. Manual ventilation ( anaesthetic bag) by relays of doctors, medical students, relatives and nurses has been effective where no mechanical ventilator was available. Anticholinesterases should always be tried Haemostatic abnormalities – strict bed rest to avoid even minor trauma; transfusion of clotting factors and platelets; ideally, fresh frozen plasma and cryoprecipitate with platelet concentrates or, if these are not available, fresh whole blood. Intramuscular injections should be avoided. Shock, myocardial damage: hypovolaemia should be corrected with colloid/ crystalloids, controlled by observation of the central venous pressure. Ancillary pressor drugs (dopamine or epinephrine-adrenaline) may also be needed. Patients with hypotension associated with bradycardia should be treated with atropine.

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Renal failure: conservative treatment or dialysis Dark brown urine ( myoglobinuria or haemoglobinuria ): correct hypovolaemia and acidosis and consider a single infusion of mannitol Severe local envenoming: local necrosis, intracompartmental syndromes and even thrombosis of major vessels is more likely in patients who cannot be treated with antivenom . Surgical intervention may be needed but the risks of surgery in a patient with consumption coagulopathy, thrombocytopenia and enhanced fibrinolysis must be balanced against the lifethreatening complications of local envenoming. Prophylactic broad spectrum antimicrobial treatment is justified

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A CASE STUDY OF PREGNANT A primi with full term pregnancy had a viper snake bite and landed to our emergency twenty hours later with labour pains.urgent coagulation profile done  ,asv started,FFP arranged and within two hours she delivered her baby.Her coagulation profile was grossly deranged and had increased creatinine levels(2.6).She lost about three liters blood, managed with asv,fresh blood ,FFP,ventilator support. Bleeding stopped, but has Acute renal shut down. Her baby also has deranged coagulation profile and has developed gradually respiratory distress and the pediatrician is suspecting pulmonary haemmorage.She has consulted many senior pediatricians but they suggest no indication for asv for the baby and deranged coagulation reports could be due to DIC.Kindly guide for role of giving asv to the newborn in such a case. Dr Soni Khurana , Consultant Intensivist , Jindal Institute of Medical Sciences, Hisar .

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Reticulated python (Python reticularis ) containing the body of a farmer it had swallowed at Palu , Sulawesi, Indonesia

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