Basic Guide to Suturing

Snake bites are a potential medical emergency even though the majority do not involve significant envenomation. The role of the clinician in these circumstances is working out which patients have been envenomated, and the select group of patient which require anti-venom.

Appropriate and timely action of first aid principles are fundamental in reducing the morbidity and mortality associated with snake bites.

Initial Assessment and Management


Recognise
  • Recognise, send for help, gather resources and appropriate equipment.
  • Move to appropriate area monitoring area.
  • Monitoring - HR, BP, RR, SpO2, Telemetry/Cardiac Monitoring (if available)
  • Identify snake if possible & avoid further envenomation by the assailant snake.
  • Apply immediate first aid principles and Pressure Immobilisation Bandage (see below) and keep the patient immobilised/still.
  • Ensure anti-venom available.
  • Liaise with a toxicologist as indicated.

Airway:
  • Assess for patency and protection
  • Intubate if respiratory failure or distress
Breathing:
  • Assess depth of breathing and respiratory rate, SpO2 + ETCO2 monitoring
  • Correct Hypoxia - SpO2 >93% in patients with no underlying lung condition
Circulation:
  • Establish IVC Access: Place in at least 1 IVC on non-affected limb for bloods.
  • 2nd IVC should be established if unstable or likely to give Anti-venom.
  • Assess for bleeding from potential bite site, mucous membranes and IVC sites
  • Commence with IV fluid. Be mindful of fluid overload. Consider appropriate IV Fluid therapy in Rhadomyolysis and acute renal failure.
Disability:
  • GCS / AVPU
  • BSL
  • Assess for signs of flaccid paralysis, cranial nerve deficits, ptosis
Exposure:
  • Check temperature, maintain normothermia
  • Urine dipstick - check for haematuria and can be used for Snake Venom Detection as well.
  • Assess for myolysis: muscle pain, tenderness or weakness

Pressure Immbolisation Bandage
Wikihow: Pressure Immobilisation Bandage


History


Signs/symptoms
  • Evidence of a bite
  • Abnormal Bleeding
  • Evidence of descending symmetrical flaccid paralysis
  • Lymphadenopathy
  • Collapse / loss of consciousness
  • Nausea, vomiting, diaphoresis
  • Headache, ptosis
  • Abdominal pain, diarrhoea
  • Myalgias
Allergies
Meds 
  • Anticoagulants, anti-platelets 
PMHx
  • Previous envenomation and/or exposure to antivenom
  • Asthma
  • Auto-immune disorders
  • Renal or Cardiovascular disease
Last oral intake
Events
  • Time and circumstances of snake bite
  • Was the snake seen, and any identifying factors of the snake (typically low-yield) - more useful if pet or snake handler
  • Number of strikes
  • First aid and PIB applied.

Investigations


  • PoC Bloods typically unreliable and not recommended 
  • INR, APPT, fibrinogen, D-dimer, 
  • FBC, U&Es, Ck
  • Snake Venom Detection Kit (can be used in conjunction with clinical + geographical information)
  • Urine dipstick

Management



Snake Antivenom

Snake anti-venom is the key treatment to managing significant evenomation and it's associated complications.
  • Indications: evidence of significant systemic evenomation (clinical or laboratory)
    • neurotoxic paralysis
    • coagulopathy
    • myotoxicity
    • acute renal impairment / failure
    • collapse and/or seizures
  • Contraindications
    • Nil absolute
    • Increased risk of anaphylaxis in those previously treated with anti-venom
  • Timing:
    • Efficacy is improved with early administration, once envenomation has been identified.
    • Risks of administrating anti-venom >24hrs post initial bite, may be greater than the risks of envenomation. Seek expert advice.
  • Choice:
    • Monovalent anti-venom is the preferred choice.
    • One vial of antivenom is now recommended to treat children and adults for all snake types.
    • The Australian Polyvalent snake venom will cover the 5 most common snake venom immunotypes in Australia and PNG. Increased risk of hypersensitivity reactions.
  • Administration
    • All patient should recieve at least 1 dose of anti-venom if indicated. Further doses may be required dependent on snake, and assessed level of envenomation. Please see Clinician's Guide to Bite and Stings for more details.
    • Be prepared to treat anaphylaxis
    • Administer 1 ampoule diluted in 500ml of 0.9% saline IV over 20 minutes. In children aim to keep total volume less than 10 mL/kg.
    • Antivenom maybe given as a rapid IV push if the patient is unstable or in cardiac arrest
  • Adverse drug reactions:
    • Anaphylaxis
    • Serum Sickness

Supportive Cares

  • Fluid therapy and feeding: A Crystalloid is appropriate for the majority of patients. In potential life-threatening bleeds the use of FFP is reasonable. Limit oral intake initially to minimize risk of venom-induced vomiting causing aspiration pneumonia.
  • Analgesia, Antiemetic: Most patients with snake bite will not have significant pain. Simple analgesia should be sufficient. If pain is increasing it may indicate myolysis which requires reassessment. Narcotics should be avoided to minimize respiratory depression.
    Anti-emetics can be useful in avoiding emesis and potential aspiration pneumonia, and also for patient comfort.
  • Antibiotics: Antibiotics are not routinely required as secondary infection from Australian snakes is uncommon. Tetanus immunity should be updated, once coagulopathy has been resolved.
  • Sedation: typically wish to avoid sedating the patient. This includes the use of sedating anti-histamines. Sedation only for intubation purposes.
  • Thromboprophylaxis: not required.
  • Head up position: nil particular position is mandated. 
  • Ulcer prophylaxis: not routinely required.
  • Glucose control: maintain normoglycaemia 5-12 mmol.
  • Skin/eye care and suctioning: routine cares, monitor for signs of bleeding
  • Indwelling catheter: typically not required, but can be useful for monitoring urine output.
  • Nasogastric tube: typically not required, and mostly should be avoided.
  • Bowel cares: routine.
  • Environment: Maintain normothermia. Keep patient or transfer patient to a monitored environment, with access to onsite pathology.
  • De-escalation (e.g. end of life issues, treatments no longer needed)
  • Psychosocial support (for patient, family and staff)

References/Further Resources

No comments:

Post a Comment