1. Local & regional anaesthesia
Mr Matt Baker

2. Aims Topical anaesthesia Lignocaine vs. bupivicaine
Digital nerve block
Wrist blocks
Haematoma block
Bier’s block
Femoral nerve block
Ankle blocks

3. Topical anaesthesia LAT gel Instillagel Soaked dental roll
EMLA/Ametop – not for open wounds

4. Local anaesthetics Lignocaine Lignocaine with adrenaline (1:200,000)
Dose: 4mg/kg
Onset: rapid
Duration: mins
Lignocaine with adrenaline (1:200,000)
Dose: 7mg/kg
Duration: 90 mins
Bupivicaine
Dose: 2mg/kg
Onset: mins
Duration: 3-8 hrs
Bupivicaine: Max dose if 75kg = 150mg = 30ml of 0.5%

5. Mechanism of action of LA
LA decrease sodium influx
Reduces rate of rise and amplitude of depolarisation
Eventually unable to achieve threshold to fire action potential
Therefore, no impulse transmitted as blocked conduction

6. LA toxicity Side effects: Management of toxicity: Neurological Cardiac
Oxygen, i.v. access, ECG monitoring, full obs
BDZ if seizure
Fluid bolus if hypotensive
Intralipid 20% 1.5ml/kg i.v. over 1 min then infusion of 0.25ml/kg/min
Occur due to overdosage of lignocaine or inadvertent intravascular injection. Can occur 10-25mins post injection.
Neuro: numbness mouth & tongue, slurred speech, lightheadedness, tinnitus, confusion, drowsiness, convulsions & coma.
Cardiac: tachycardia & hypertension then hypotension with bradycardia & heart block. Occ ventric arrhthymias and arrest.

7. 1. Digital nerve blocks Use 1-2ml lignocaine on either side of finger
Inject from dorsal side
If big toe or proximal phalanx, give extra injection of LA across dorsum of digit to cover dorsal digital nerves
Single injection technique
+/- adrenaline
Some evidence that using lignocaine + adrenaline in digital nerve blocks does not cause necrosis and ischaemia.
Digital nerves derived from medial and ulnar nerves and divide into paired palmar branches.
Dorsal digital nerves derived from radial and ulnar nerves and supply dorsal aspect of prox phalanx.

8. 2. Wrist blocks Median nerve: Ulnar nerve: Radial nerve:
Radial half palm
Thumb, index & middle fingers
Radial half of ring finger
Ulnar nerve:
Ulnar border hand
Little finger
Ulnar half ring finder
Radial nerve:
Dorsum of radial side hand

9. 2. Wrist blocks Median nerve:
Between palmaris longus & flexor carpi radialis
Ask patient to flex wrist and oppose thumb & little finger
Inject between tendons at proximal wrist crease
5ml 1% lignocaine
1ml subcut. to block palmar cutaneous branch
Use approx 5ml 1% lignocaine
-Palmar cutaneous branch supplies sensation to skin of thenar eminence and palm
-If no palmaris longus, then inject ulnar side of FCR

10. Median Nerve

11. Ulnar nerve Palmar branch: Dorsal branch: Inject:
runs with ulnar artery
Supplies hypothenar eminence & palm
Dorsal branch:
Passes under FCU
Supplies ulnar border of dorsum of hand
Inject:
Between artery & FCU
Plus around ulnar border wrist
Inject between artery and FCU at level of ulnar styloid process, approx 5ml 1% lignocaine

12. Radial nerve
Radial nerve lies subcutaneously on dorsum of wrist & divides into branches
Infiltrate 5ml 1% lignocaine subcutaneously around radial side of wrist from FCR to radio-ulnar joint

13. 3. Haematoma block
10ml 1% lignocaine into haematoma from dorsal aspect of wrist
Occ. need few ml’s around ulnar styloid too
No monitoring required
Risks:
Infection
LA toxicity
No use once > 24hrs old as haematoma organised

14. Bier’s block 40ml 0.5% prilocaine (30ml if elderly or frail)
Full monitoring in resus.
i.v. access both arms
Check radial pulse then elevate arm to exsanguinate
Inflate tourniquet to at least 100mmHg above SBP (record time)
Inject prilocaine into isolated limb
Test after 5 mins
Manipulate, remove cannula and apply POP
Keep inflated for at least 20 mins then deflate slowly & record time. Watch for signs of toxicity
Contraindications: Severe hypertension, severe PVD, sickle cell, Raynauds, MetHb, procedures required in both arms

15. Haematoma vs. Biers block
Personal choice
Best Bets:
Biers block better in terms of pain score & need for remanipulation
Variable findings re. Xray results
Less risk of side effects with haematoma block and only need one doctor present

16. 4. Femoral nerve block Femoral nerve supplies: Hip Knee
Muscles in anterior compartment of thigh
Skin of medial & anterior thigh
Skin of medial aspect of leg below knee
Skin below knee = saphenous nerve

17. Femoral nerve block
Insert needle approx 0.5 – 1cm lateral to femoral artery perpendicular to skin
Stand on opposite side
Use lignocaine plus bupivicaine or bupivicaine alone
Stand to left side if right femoral nerve (if right hand dominant)
Compress artery if puncture it

18. 5. Ankle blocks Five nerves: Saphenous n. Superficial peroneal n.
Deep peroneal n.
Sural n.
Tibial n.
Use lignocaine or bupivicaine
Approx 5ml required
Saphenous n = medial side ankle
Common peroneal nerve – from tibial nerve, divides just below head of fibula.
Superficial peroneal n. = front ankle & dorsum foot
Deep peroneal n. = 1st dorsal web space
Sural n. = heel & lateral border of foot
Tibial n. = anterior half of sole

19. (i) Saphenous nerve:
Subcut. infiltration around great saphenous vein, anterior & just above medial malleolus
Aspirate to ensure not intravascular injection
Supplies: medial side of ankle

20. (ii) Superficial peroneal nerve:
Subcut. infiltration above ankle joint from anterior border of tibia to lateral malleolus
Supplies: front of ankle and dorsum of foot

21. (iii) Sural nerve
Emerges from between heads of gastrocnemius on lateral side of Achilles then descends behind lateral malleolus
Infiltrate from lateral border of Achilles tendon towards to the lateral malleolus
Heel and lateral border of foot

22. (iv) Deep peroneal nerve:
Located between EHL & EDL
Nerve is lateral to dorsalis pedis pulse
Insert needle between tendons ‘til touch bone then infiltrate as withdraw needle
Supplies: 1st dorsal web space

23. (v) Tibial nerve: Palpate posterior tibial artery
Insert needle medial to Achilles tendon, lateral to artery, level with upper border of malleolus
Supplies: anterior half of sole

24. Summary Various blocks that are simple to do and effective
Always watch for signs of LA toxicity
Hard to remember them all so look them up and try them out!

25. Any questions?