Immediately apply pressure bandage with immobilization first aid if not already applied, unless the patient is in a medical facility and does not have clinical evidence of severe envenoming.

 

All patients require medical attention.

 

Even trivial looking bites may result in severe envenoming; asymptomatic patients following possible envenoming must be observed for a minimum of 12 hours and should be observed overnight.[3][4]

 

Patients must be closely observed for the onset of symptoms including:

The coagulation screen and blood investigations along with a neurological examination must be performed upon presentation, 1 hour after removal of the pressure bandage, and repeated at 6 hours and 12 hours after the bite.[4]

If at 12 hours post-bite all the blood tests are normal and there is no clinical signs of neurotoxicity the patient is eligible for discharge.[4] The patient should be advised to return if there is any indication of illness including change in their urine color or if they develop any muscle pain, tenderness, or weakness.

 

 

If envenoming is evident, do not remove pressure bandage with immobilization first aid until antivenom has been administered.[3]

 

If there are no clinical or biochemical signs of envenoming only remove pressure bandage with immobilization first aid once an IV line has been inserted and antivenom and advanced resuscitation facilities are at hand.[3][4][5] A bite site swab can be saved for possible venom detection kit (VDK) testing if evidence of envenoming becomes evident. However, VDK analysis is not always necessary. Determination of the appropriate antivenom required to treat an envenomed patient can often be determined through clinical and laboratory features of envenoming and the geographical location of the snakebite.

 

Once the pressure bandage is removed repeat blood tests at 1 hour after removal.[4] If these results are normal and there are no signs of neurotoxicity repeat blood tests again at 6 hours (unless already > 6 hours) and 12 hours after the bite.[4] If clinical signs or biochemical findings indicate systemic envenoming then antivenom should be administered.[6] If at 12 hours post-bite all the blood tests are normal and there is no clinical signs of neurotoxicity the patient is eligible for discharge.[4]

 

 

Adequate hydration is required to reduce the incidence of renal damage.[6]

 

Hydration should be maintained through administration of oral or intravenous fluid to ensure a good urine output.

 

Normal (0.9%) saline dose

 

CHILD

 

ADULT

Be circumspect when inserting IV lines, as there will be continued oozing from all sites until the coagulopathy reverses, which will be at least 6 hours, usually more. Avoid insertions in sites where bleeding cannot be easily controlled, such as subclavian, femoral, and jugular veins.

 

In all cases of suspected snakebite conduct:

All patients must then be observed for a minimum of 12 hours.[4]

 

 

The role of venom detection kit in the management of snakebite in Australia varies across geographical areas. In some areas the choice of antivenom in cases of envenoming can be made based on the clinical syndrome and geographical area the snakebite occurred. Snake venom detection kits are more likely to be useful in areas where the envenoming may have been caused by more than two possible snakes. The opinion of the patient or a witness, no matter how experienced in snake identification, should not be accepted without question.[7] The Snake Venom Detection Kit is used to establish the correct antivenom to administer - if required. The result of a snake venom detection kit does not indicate that major envenoming has occurred and is not an indication antivenom is required.[8] A positive snake venom detection result from the bite site (preferred sample site) indicates venom is present and the type of antivenom required to treat the patient in the case of clinical or laboratory evidence that envenoming has occured.[9] The decision to give antivenom should be based on clinical and laboratory evidence of systemic envenoming.[2][9][8][10][11] Conversely, a negative result should not be used to exclude envenoming.[8]

 

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[8] and should not be tested in patients who do not have evidence of systemic envenoming.[10]

 

If pressure bandage with 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.[5] Retain the cut section of bandage as it may later be used for further venom identification.

 

 

Insert a secure intravenous line and take blood for:

 

Coagulopathy screen:

Full blood count (FBC) including:

Serum electrolytes including:

Serum urea

Serum creatinine

Serum creatine kinase (CK)

Collect urine

Admission to an intensive care environment is recommended for patients who develop any signs of envenoming or abnormal blood results.

 

Following a brown snake bite there is minimal or no local pain at the wound site, rarely swelling or erythema, and as the fangs are small the injury can be virtually invisible;[22][28][29] adults may not even be aware they have been bitten.[30][31]

 

Initial systemic symptoms can include nausea, vomiting, abdominal pain, headache, and dizziness.[32][33][34][35] Sudden loss of consciousness, typically with spontaneous recovery, may occur early in the course of envenoming.[22][33] There is potential for hypotension, cardiac dysrhythmia, and rarely arrest.[14][22][36] Bleeding and/or ooze from the bite site or subsequent venepuncture is an early indication of venom induced consumption coagulopathy (VICC), which is the hallmark of brown snake envenoming.[22][33][36] This coagulopathy may potentially lead to complete defibrination and non-clotting blood. International normalized ratio (INR) and activated partial thromboplastin time (aPTT) will be prolonged, fibrinogen low to absent, and fibrin degradation products (FDP) and D-dimer immunoassay elevated.[37][12][38][39][40][41] Although hemorrhage is a major concern, spontaneous bleeding is uncommon to rare.[14][36] Thrombotic microangiopathy with thrombocytopenia and microangiopathic hemolytic anemia may additionally occur,[36] but is not common; platelet counts typically remaining normal in most cases.

 

Neurotoxicity is rare and typically only results in mild effects such as ptosis.[22] Seizure may occur, more commonly in children, but it does not appear to be related to neurotoxins. Acute kidney injury may occur[36] and it more commonly develops in adults. It appears that most, possibly all cases of acute kidney injury are not primarily caused by venom nephrotoxicity but likely secondary to other effects of envenoming such as thrombotic microangiopathy.[38] Myolysis is not typically a feature of brown snake envenoming.[22][36]

 

Clinical effects usually develop following a dermal exposure (bite). Snakebite to the eye or contamination of the eye with snake venom is an unlikely route of exposure.

 

Early collapse, if present, is typically the first feature, developing within 5 to 30 minutes.[22][33] Between 30 and 120 minutes there may be lymph node pain and early nonspecific systemic features. Coagulopathy typically develops over 1 to 2 hours post-envenoming,[12] although complete defibrination can occur by 15 to 30 minutes.[14] If neuromuscular paralysis develops the first signs of ptosis may be evident 2 to 6 hours post-bite. Paralysis can be also delayed and may evolve over 12 to 24 hours.[7][21][32][42]

 

Coagulopathy typically resolves over 12 to 18 hours.[22][43] Paralysis following snakebite may take days or weeks to resolve.[44]