IDENTIFICATION
SPECIES NAME
Scientific Name | Common Name(s) |
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| Speckled brown snake | | Downs tiger snake |
| Ringed brown snake | | Five ringed snake | | Five ringed brown snake |
| Gwardar | | Western brown snake |
| Common brown snake | | Eastern brown snake |
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INTERVENTION CRITERIA
Any individual suffering a suspected or actual snake bite requires admission for medical observation and treatment as necessary.
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In all cases of suspected snake bite conduct: Snake venom detection kit Blood investigations All patients must then be observed. Snake Venom Detection Kit identification Conduct testing with the CSL Snake Venom Detection Kit. The opinion of the patient or a witness, no matter how experienced in snake identification, should not be accepted without question. The Snake Venom Detection Kit must be used to establish the correct antivenom to administer - if required. A positive snake venom detection result from the bite site (preferred sample site) indicates venom is present and the type of venom. It does not indicate that major envenoming has occurred and is not an indication antivenom is required. The decision to give antivenom should be based on clinical and laboratory evidence of systemic envenoming. Urine may be tested using the snake venom detection kit if there is evidence of significant systemic envenoming and a bite site swab is either unavailable, or has tested negative. Urine may sometimes give false positives and should not be tested in patients who do not have evidence of systemic envenoming. If pressure-immobilization first aid has been applied, do not remove the bandage, rather, cut away a section immediately over the bite area and swab for venom detection. Retain the cut section of bandage as it may later be used for further venom identification. Blood Investigations Insert a secure intravenous line and take blood for: Coagulopathy screen: International Normalized Ratio (INR) or prothrombin time (PT) Activated Partial Thromboplastin Time (aPTT) Fibrinogen level Fibrin Degradation Products (FDP)/D-dimer Immunoassay If laboratory facilities are not readily available then conduct a whole blood clotting time: Collect 5 to 10 mL of venous blood in a GLASS test tube and measure the time required for the blood to clot Time to clot > 10 minutes Suspicious of coagulopathy >20 minutes and no clot Indicative of severe coagulopathy - Determine if the patient is taking any pharmaceuticals likely to interfere with coagulation function, as this will influence interpretation of the coagulation tests. - If possible a control should be run using normal blood from a person taking no anticoagulant drugs (such as a staff member). Full blood count (FBC) including: Platelets White blood cells (especially absolute lymphocyte count) Serum electrolytes including: Potassium Serum urea Serum creatinine Serum creatine kinase (CK) Collect urine (may be required for subsequent Snake Venom Detection Kit testing) |
Intravenous FluidsIntravenous hydration is required to reduce the incidence of renal damage:
Normal (0.9%) SalineNormal (0.9%) saline dose
CHILD
Adjust adult dose to body weight
ADULT
| Initial fluid load |
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| 1 L IV over 2 to 3 hours |
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|
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| Continue infusion at |
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| 100 to 150 mL IV per hour for 6 to 12 hours |
Be circumspect when inserting IV lines, as there will be continued oozing from all sites until the coagulopathy reverses, which will be at least 3 hours, usually more. Avoid insertions in sites where bleeding cannot be easily controlled, such as subclavian, femoral and jugular veins.
ObservationEven trivial looking bites may result in severe envenoming, asymptomatic patients must not therefore be discharged prior to 12 hours following possible envenoming; and should be observed overnight.
Patients must be closely observed for the onset of symptoms including; Paralysis |
| Ptosis (drooping eyelids) |
| Ophthalmoplegia (paralysis of motor nerves of the eye) | Renal failure |
Blood tests should then be repeated at the end of the period of observation, and the patient eligible for discharge if results are normal.
Removal of pressure immobilization first aidDo not remove pressure immobilization first aid unless there are no clinical or biochemical signs of envenoming; and, antivenom and advanced resuscitation facilities are at hand.
If envenoming is evident, do not remove pressure immobilization first aid until antivenom has been administered.
Only remove pressure immobilization first aid once an IV line has been inserted; a Snake Venom Detection Kit analysis has been performed; and blood test results have been reported and show no indication of envenoming.
Blood tests should be repeated 2 to 3 and 5 to 6 hours later. If clinical signs or biochemical findings indicate systemic envenoming then antivenom should be administered.
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Any patient with symptoms or abnormal blood results must be admitted to a medical facility with antivenom and an intensive care environment.
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TREATMENT
TREATMENT SUMMARY
Rapid and effective diagnosis is imperative. While 75% of brown snake bites do not lead to systemic envenoming, all cases should be considered potentially lethal, and all must be admitted. Application of pressure immobilization first aid prior to initial patient movement is life-saving in conjunction with subsequent antivenom administration. Cardiac dysrhythmia/arrest and seizure or collapse may require immediate management. IV fluids are required to ensure renal perfusion and, if there is evidence of systemic envenoming, administration of sufficient quantities of appropriate antivenom is crucial. Hemorrhage should be managed with antivenom. However, if immediately life-threatening, fresh frozen plasma or coagulation factors may be considered. Renal failure is managed using standard procedures but may be associated with disseminated intravascular coagulation. Should the latter occur, circulating venom must be fully neutralized with antivenom before standard management of disseminated intravascular coagulation is employed. Avoid medications likely to depress respiratory function or interfere with platelet function, and ensure tetanus status is adequate (do not give any IM injections until coagulopathy is reversed - to avoid iatrogenic intramuscular hematoma). |
EMERGENCY STABILIZATION
Ensure Adequate Cardiopulmonary Function |
Ensure the airway is protected if compromised (intubation may be necessary). |
Immediately establish secure intravenous access. |
Pressure-Immobilization First Aid |
- Reassure the patient and ensure they remain still.  - Remove any watch, rings, bracelets or other jewellery from the bitten limb. - A broad compression bandage should be applied over the bitten area about as firmly as that used for a sprained ankle. Elasticized bandages are preferable, but crepe bandages, clothing strips or pantyhose will suffice in an emergency. - It is very important that the patient is not moved. If clothing cannot be cut from a bitten limb then a compression bandage should be applied over the clothing - rather than move an arm or leg. - A second bandage should then be applied, starting from the tip of the limb (fingers or toes) and heading toward the body, as firmly as used for a sprained ankle. Elasticized bandages are ideal for this purpose, but crepe bandages, strips of clothing or towels may be used. - Immobilize the arm with a sling; or the leg with a splint and then bandage the split to the limb to prevent movement. Ensure the patient is told not to move at all. - Transport (preferably an ambulance) should be brought to the patient to prevent movement. If this cannot be done, the patient should be carried rather than walk. - Do not give alcohol, fluid, or food by mouth. If the patient will not reach medical care for a long period, only water should be given by mouth. - Transport to hospital. - Tourniquets should not be used. The bite site should not be washed, cleaned, cut, sucked, or treated with any subsatnce. |
Be circumspect when inserting IV lines, as there will be continued oozing from all sites until the coagulopathy reverses, which may take at least 3 hours, usually more. Avoid insertions in sites where bleeding cannot be easily controlled, such as subclavian, femoral and jugular veins.
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Cardiac arrest or dysrhythmia are likely short-lived as the precipitating blood clot will be dissolved by fibrinolysis. Resuscitation should follow standard procedures for cardiac arrest.
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Toxic seizures are generally self-limiting and are unlikely to require specific treatment.
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CHILD Where the systolic blood pressure is below normal blood pressure ranges for the age group: Age (years) | Normal Systolic Blood Pressure (mmHg) | <1 | 70 to 90 | 1 to 2 | 80 to 95 | 2 to 5 | 80 to 100 | 5 to 12 | 90 to 110 | >12 | 100 to 120 |
Administer normal (0.9%) saline 10 mL/kg IV over 5 to 10 minutes If the systolic blood pressure does not return to the normal range, give a further 10 mL/kg body weight normal saline over 5 to 10 minutes. If intravenous access cannot be obtained consider intra-osseus access ADULT Administer a bolus of normal saline if systolic blood pressure is less than 100 mmHg. Normal (0.9%) saline dose: 10 mL/kg IV over 5 to 10 minutes If the systolic blood pressure does not return to the normal range, give a further 10 mL/kg body weight normal saline over 5 to 10 minutes. |
Blood pressure 12 lead ECG
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DECONTAMINATION
Decontamination Not Recommended |
Do not clean the wound prior to use of a Snake Venom Detection Kit. This will remove venom which otherwise might allow identification of the culprit.
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SIGNS AND SYMPTOMS
Following a brown snake bite there is minimal or no local pain at the wound, rarely swelling or erythema, and as the fangs are small the injury can be virtually invisible; adults may not even be aware they have been struck. Initial symptoms can include nausea, vomiting, headache, abdominal pain. Sudden loss of consciousness may occur in adults, and seizure in children. There is potential for cardiac dysrhythmia, and rarely arrest.
Bleeding and/or ooze from the bite site (or subsequent venepuncture) is an early indication of coagulopathy, characteristic of brown snake envenoming. Paralysis is uncommon and heralded by ptosis and ophthalmoplegia. Primary or secondary renal failure can develop, but myolysis does not occur.
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Onset/Duration of Symptoms |
Onset of systemic envenoming can occur within 5 to 15 minutes, or may be delayed by many hours.
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The majority (75%) of venomous Australian brown snake (Pseudonjaja sp.) bites do not produce an effective envenoming. However, brown snakes are the most common cause of snake-bite related death in Australia; 10 to 20% of successful envenomings proving fatal without treatment. Prior to antivenom being developed about 8% of all brown snake bites were fatal. |
Do Not Archive. This document is current on day of issue,
NZ: 18.May.2012 |
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