Anaesthesia - Topical

Disclaimer

These guidelines have been produced to guide clinical decision making for the medical, nursing and allied health staff of Perth Children’s Hospital. They are not strict protocols, and they do not replace the judgement of a senior clinician. Clinical common-sense should be applied at all times. These clinical guidelines should never be relied on as a substitute for proper assessment with respect to the particular circumstances of each case and the needs of each patient. Clinicians should also consider the local skill level available and their local area policies before following any guideline. 

Read the full PCH Emergency Department disclaimer.

Aim

To guide staff in the use of topical anaesthesia in wounds.

Key Points

Topical anaesthetics are useful for children with wounds requiring suturing or debridement. 

Description

ALA (Laceraine)

Sterile wound anaesthetic:
  • Adrenaline 0.1% w/v (1:1000 or 1mg/mL).
  • Lignocaine HCL 4% M/V (40mg/mL).
  • Tetracaine (Amethocaine) 0.5% M/V (5mg/mL).
  • Onset: 20-30 minutes.
  • Duration: 30-60 minutes.

Indications

  • Topical use on broken skin.
  • Local anaesthesia for wound management (cleaning, closure).
  • Haemostasis.

Contraindications

  • Do not use on digits, pinnae, tip of nose, penis, or other end arterial areas.
  • Not for dental use or where entry into major blood vessels may occur.
  • Not meant for use on intact skin - consider EMLA®.
  • Do not apply to mucous membranes.
  • Do not use on wounds >7 cm, bites, contaminated or complex wounds, burns, extensive abrasions.
  • Do not use in patients with hypersensitivity to any local anaesthetic.

Adverse reactions

  • Systemic toxicity is rare and invokes mainly CNS (usually first) and CVS effects:
    • Restlessness, dizziness, tinnitus, nausea and vomiting, tremors, convulsions, CNS depression.
    • Numbness of the tongue and perioral region may be an indicator of early systemic toxicity.
    • Cardiac effects are myocardial depression and vasodilation.

Dosage preparation

  • Use a syringe and draw up 0.1 mL/kg (maximum 3mL) from the 5ml vial
    • 0.1mL/kg = 4mg/kg of lignocaine.

Administration

  • Clean wound, removing debris and clotted blood.
  • Wearing gloves.
    • Soak cotton balls with the ALA and apply to wound
    • Cover cotton balls and are around wound with Tegaderm™ / Opsite.
  • Advise child / carer
    • May sting on first application.
    • Not to interfere with site.
  • Leave for 20-30 minutes (maximum 60 minutes)
    • Test sensation prior to further treatment.
    • Blanching at edges is usual.
  • Supplemental 1% lignocaine can be used intradermally as long as a total lignocaine does not exceed 5mg/kg
  • Maximum additional lignocaine dose 1mg/kg = 0.1mL/kg of 1% lignocaine.

Bibliography

  1. AMH Children’s Dosing Companion (2015) Australian Medicines Handbook Pty Ltd
  2. Australian Injectable Drugs Handbook (AIDH) - 7th Edition 201
  3. Pediatric & Neonatal Dosage Handbook 24th Edition Carol K. Taketomo, PharmD

Endorsed by:  Director, Emergency Department  Date:  Feb 2018


 Review date:   Feb 2021


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