Giving local anaesthetic before closing a wound

Well lit area.
Wear mask.
Wear safety glasses.
Sterile technique.
 
Sharps disposal.

Local anaesthetic (LA) used to numb area before doing painful procedure (eg suturing)

Attention

  • Do not use local anaesthetic + adrenaline (epinephrine) for fingers, toes, penis
  • 2–5mL of lidocaine (lignocaine) 1% usually needed for most procedures
    • Maximum safe dose is 3mg/kg up to 200mg OR medical consult for higher dose
    • Lidocaine (lignocaine) 1% is 10mg/mL
  • If wound bleeding use lidocaine (lignocaine) 1% + adrenaline (epinephrine) 1:100,000
  • Topical anaesthetic (skin) patches
    • Do not leave on for more than one hour — anaesthetic may be absorbed and cause symptoms such as dizziness, headache, fast pulse, cyanosis (blue skin), especially in children
  • Before injecting, always pull back on (withdraw) syringe plunger to make sure you are not in vein/artery
  • To lessen pain
    • Warm local anaesthetic to room temperature and inject s-l-o-w-l-y
    • Consider using anaesthetic spray on skin before first injection
    • Commence through the wound edge
  • LA can be injected as needle pulled back out through tissue. Will anaesthetise all tissue in its path
    • If needle pulled out steadily and continuously — LA should not be injected into vein or artery — practice on a piece of meat
  • ‘Fanning’ — technique used to inject wide area of tissue from single injection point
    • Needle put in at one spot then moved around in clockwise or anti-clockwise direction to anaesthetise a bigger area (eg sural (foot) nerve block, episiotomy)
  • Wait 10 minutes for LA to work before starting procedure
    • Check area for feeling using sharp needle. Also gives person confidence
    • Ask person to feel around their own wound to give them confidence that local anaesthetic is working

Direct infiltration

Attention

  • Try flushing wound with small amount of LA before first injection. Wait 2–3 minutes for this to work
  • Do not go too deep with injection. Anaesthesia may be delayed or not work at all
  • Aim to put needle below dermal layer of skin and above fat layer
  • If needle in dermal layer — will be hard to press down syringe plunger. Take it out, try again a little deeper
  • Scalp wounds may need bigger needle to infiltrate — tissue is tough

What you need

  • Bluey
  • Sterile dressing pack
  • Normal saline for cleaning
  • 2–5mL of lidocaine (lignocaine) 1%
  • 5mL syringe, 21G needle for drawing up, 23G or 25G needle for injection
  • Sterile gloves

What you do

  • See Examining and cleaning a wound before closing
  • Put bluey under site
  • Lay out dressing pack, equipment
  • Wash hands, put on sterile gloves
  • Clean site, drape with sterile towels
  • Draw up LA
  • Starting at one end of wound, slide needle through wound edge under dermal layer and above fat — Figure 7.26, needle a
    • Pull back on plunger to check for vein/artery, then inject anaesthetic as you pull needle out. Will anaesthetise shaded area around AFigure 7.26
    • Wait a few moments until anaesthetic is working, so person doesn't feel it, then push needle into anaesthetised area at tip of previous injection — Figure 7.26, needle b. Repeat injection as above
    • Keep doing this until wound is anaesthetised along its whole length, then repeat process on other side — Figure 7.26, needle c and needle d
    • If wound short — may only need 1 injection on each side
  • Make sure ends of wounds also injected with LA
  • Wait for anaesthetic to work. Use needle to test for feeling before you start suturing

Figure 7.26  

Give repeated injections of local anaesthetic along both sides of wound edge until total area anaesthatised.

Parallel margin infiltration

Attention

  • More painful than direct infiltration. Only use if wound very dirty and needle may take dirt further into tissue

What you need

  • Bluey
  • Sterile dressing pack
  • Normal saline for cleaning
  • 2–5mL of lidocaine (lignocaine) 1%
  • 5mL syringe, 21G needle for drawing up, 25G needle for injection
  • Sterile gloves

What you do

  • See Examining and cleaning a wound before closing
  • Put bluey under site
  • Wash hands, put on sterile gloves
  • Lay out dressing pack, equipment
  • Clean site, drape with sterile towels
  • Draw up LA
  • Starting at one end of wound about 4mm from edge, push needle in, keeping parallel to wound edge — Figure 7.27, needle a
    • Pull back on plunger to check you are not in vein/artery, then inject anaesthetic as you pull needle out
    • Wait a few moments, push needle into anaesthetised area at tip of previous injection, inject as before — Figure 7.27, needle b
    • Keep doing this until wound anaesthetised along its whole length, then repeat process on other side — Figure 7.27, needle c and needle d
    • If wound short — may only need 1 injection on each side
  • Make sure ends of wounds also injected with LA
  • Wait for anaesthetic to work. Use needle to test for feeling before you start suturing

Figure 7.27  

Give repeated injections of local anaesthetic along both sides of wound, 4mm from edge, until total area anaesthatised.