Snake or spider bite

Any person, 16 years and over, presenting with a suspected or confirmed bite from a snake or spider.

Escalate immediately as per local CERS protocol for all snake and suspected funnel-web spider bites.

History prompts, signs and symptoms

These are not exhaustive lists. Maintain an open mind and be aware of cognitive bias.

Red flags

Recognise: identify indicators of actual or potential clinical severity and risk of deterioration.

Respond: carefully consider alternative ECAT protocol. Escalate as per clinical reasoning and local CERS protocol, and continue treatment.

Clinical assessment and specified intervention (A to G)

If the patient has any Yellow or Red Zone observations or additional criteria (as per the relevant NSW Standard Emergency Observation Chart), refer and escalate as per local CERS protocol and continue treatment.

Position

Assessment	Intervention
General appearance/first impressions	Position of comfort Keep patient immobile

Airway

Assessment	Intervention
Patency of airway	Maintain airway patency Consider airway opening manoeuvres and positioning If airway adjuncts are required, insert them gently and consider the potential for bleeding

Breathing

Assessment	Intervention
Respiratory rate and effort Auscultate chest (breath sounds) Oxygen saturations (SpO2)	Assist ventilation, as clinically indicated Consider oxygen if dyspnoeic, titrate oxygen to maintain SpO2 over 93% Patients at risk of hypercapnia, maintain SpO2 at 88–92%

Circulation

Assessment	Intervention
Snake or funnel-web spider bite	Apply pressure bandage with immobilisation (PBI) Use a broad, 15 cm, elasticised bandage. The bandage is applied over the bite site and then distally to proximally, covering the whole limb. Leave bandage in situ if already placed, or reinforce if current bandage is inadequate Hourly neurovascular observations of the affected limb to ensure perfusion is maintained Include assessment of sensation, motor function and perfusion, i.e. pulses, colour, temperature, swelling and capillary refill
Redback spider bite	A pressure bandage is not recommended, and will only make the pain worse Cold packs or heat packs may help relieve pain
Bleeding	Look for bleeding from the bite site, cannulation site or occult sites , e.g. gastrointestinal, urinary or intracranial Consider as a sign of envenomation
Perfusion (capillary refill, skin warmth and colour) Pulse Blood pressure Cardiac rhythm	Assess circulation Attach cardiac monitor and complete 12 lead ECG if BP/HR are within the Yellow or Red Zones, or where clinically relevant, e.g. irregular pulse, palpitations, syncope, shock, respiratory compromise, cardiac history or clinical concern
IVC and/or pathology	Insert IV cannula, if trained and clinically indicated If unable to obtain IV access, consider intraosseous, if trained See pathology section
Signs of shock: tachycardia and CRT 3 seconds and over and/or abnormal skin perfusion and/or hypotension	If signs of shock present and/or SBP less than 90 mmHg, give 250 mL of sodium chloride 0.9% IV/intraosseous bolus Repeat every 10 minutes (up to 1000 mL) until SBP over 90 mmHg or signs of shock have resolved

Disability

Assessment	Intervention
GCS, pupillary response and limb strength	Obtain baseline and repeat assessment as clinically indicated Consider altered conscious state as a sign of envenomation
Pain	Assess pain. If indicated, give early analgesia as per analgesia section then resume A to G assessment

Exposure

Assessment	Intervention
Temperature	Measure temperature
Skin inspection, including posterior surfaces	Look for bite sites, but do not remove pressure bandage Palpate lymph nodes for tenderness

Fluids

Assessment	Intervention
Hydration status – last ate, drank, bowels opened, passed urine or vomited	Commence fluid balance chart, as required
Nausea and/or vomiting	If present, consider envenomation and see nausea and/or vomiting section Antivenom takes precedence over symptom management

Glucose

Assessment	Intervention
BGL	Measure BGL, if clinically indicated If less than 4 mmol/L, consider hypoglycaemia protocol

Focused assessment

• Complete a cardiovascular focused assessment.
• Complete a neurological focused assessment.

Precautions and notes

• See NSW Health Snake and Spider Bites Clinical Management Guideline.
• Do not remove pressure bandage with immobilisation (PBI) until:
  • antivenom is readily available
  • a medical review has occurred
  • there are no clinical signs of envenomation
  • laboratory investigations have occurred and bloods have returned to normal.
• Risk of anaphylaxis with antivenom is highest in the first hour post administration.

Snake bite

• A snake bite observation chart is recommended for recording specific signs associated with snake bites or envenomation.
• Snake bite victims with significant coagulopathy: IM injections should usually be avoided, except for Boostrix or ADT booster.
• Point of care testing (PoCT) devices are inaccurate in testing for INR, aPTT and D-dimer in snake bite and should not be used.
• Patients with a suspected snake bite must be transferred to a hospital with formal laboratory facilities unless an INR can be done locally with a result available within 2 hours. However, if systemic envenomation is evident, antivenom should be given before transfer. Be prepared to manage anaphylaxis and discuss with the Poisons Information Centre 13 11 26 or local clinical toxicologist if this occurs.

Interventions and diagnostics

Specific treatment

• Treatment is focused on determining if patient is envenomed and what treatment is required. This is done in consultation with a local medical practitioner and the Poisons Information Centre 13 11 26 or local clinical toxicologist.
• Identification of the snake should only be done by experts. Snake handlers may be able to assist in the identification of snakes. However, Australian snakes have overlapping shapes, sizes and colours and non-expert identification is generally incorrect.
• Systemic envenomation: prepare for administration of antivenom.
• Venom-induced consumptive coagulopathy (VICC) – life-threatening bleed: consider early administration of fresh frozen plasma (FFP) if actively bleeding, in consultation with a medical practitioner and local clinical toxicologist.
• Funnel-web spider envenomation: prepare for administration of antivenom.
• Redback spider envenomation: provide effective analgesia.
• Antivenom administration: if patient proceeds to antivenom administration, prepare equipment to manage anaphylaxis. Consider anaphylaxis or allergic reaction protocol.

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Analgesia

Select pain score:

• 1–3 (mild)
• 4–6 (moderate)
• 7–10 (severe)

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Nausea and/or vomiting

If nausea and/or vomiting is present, give:

• metoclopramide 10 mg orally or IV/IM once only (over 20 years only)
• or ondansetron 4 mg orally or IV/IM. If symptoms persist after 60 minutes, repeat once, maximum dose 8 mg
• or prochlorperazine 5 mg orally once only or 12.5 mg IV/IM once only

Choice of antiemetic should be determined by cause of symptoms.

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Tetanus

If patient has a ‘tetanus-prone’ wound, consider giving a tetanus booster vaccine.

• Diphtheria and tetanus (ADT booster) vaccine should be given as per the Australian Immunisation Handbook Guide for tetanus prophylaxis in wound management.
• If ADT booster is not available then diphtheria/tetanus/pertussis (Boostrix) vaccine can be used.
• If no documented history of a primary vaccination course (3 doses) with a tetanus toxoid-containing vaccine: refer to medical or nurse practitioner or nurse immuniser.
• If pregnant or breastfeeding: dTpa vaccine (diphtheria-tetanus-acellular pertussis) is recommended. Refer to medical or nurse practitioner or nurse immuniser.

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Radiology

Not usually indicated. If there is concern for urgent radiology, escalate care as per local CERS protocol.

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Pathology

Snake bite

• Point of care cannot be used – formal laboratory testing is needed
• FBC, UEC, CK
• Coags: including INR, aPTT, fibrinogen, d-Dimer
• Urinalysis: collect and check for blood which may indicate myoglobinuria or haemoglobinuria

Funnel-web spider bite

• Experiencing extreme hypertension or is hypotensive: troponin

Medications

The shaded sections in this protocol are only to be used by registered nurses who have completed the required education.

Medications with contraindications or requiring dose adjustment are marked:

• ^H for patients with known hepatic impairment
• ^R for patients with known renal impairment.

Escalate to medical or nurse practitioner.

Evidence informed	Information was drawn from evidence-based guidelines and a review of latest available research. For more information, see the development process.
Collaboration	This protocol was developed by the ECAT Working Group, led by the Agency for Clinical Innovation. The group involved expert medical, nursing and allied health representatives from local health districts across NSW. Consensus was reached on all recommendations included within this protocol.
Currency	Due for review: Jan 2026. Based on a regular review cycle.
Feedback	Email ACI-ECIs@health.nsw.gov.au