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Regional Anaesthesia - Coggle Diagram

- - - - Superior to umbilicus
    - - Iliohypogastric & ilioinguinal nerves supply inferior to umbilicus
    - - Periumbilical area
    - - Inguinal
    - - Inguinal sac/scrotum/labia/medial thigh
  - - - Consent/aseptic/no contraindications/AAGBI monitoring
      - US machine
        
        Linear or curvilinear probes
        
        Sterile cover
        
        0.5% chlorhex spray
        
        50-100mm block needle
        
        20-40ml LA
      - Pt supine, probe transverse to patient, mid axillary line between ribs and iliac crest
      - In plane approach - aim internal oblique and transversus abdominus plane
      - Inject saline to confirm position, then LA via 5ml aliquots to ensure correct spread
    - - Triangle of Petit identified via
        
        Palpation iliac crest inferiorly
        
        Latissimus dorsi posteriorly
        
        Posterior border of external oblique anteriorly
      - 50mm needle
      - Perpendicular to skin just above iliac crest in posterior axillary line
      - 2 pops felt as go through external, then internal obliques
      - Negative aspirate
  - - - Variation in LA spread
    - - Large volumes especially if bilateral
    - - Intraperitoneal/intrahepatic/bowel perf/haematoma
- - - - Skin above clavicle
      - Shoulder tip
      - 1st 2 intercostal spaces anteriorly
    - - Skin over deltoid
    - - Skin over medial arm and axilla
    - - ACJ, capsule, glenohumeral joint
    - - Inferior aspect of capsule and glenohumeral joint
    - - Variable input
  - - - Phrenic nerve block/damage
      - Stellate ganglion block/damage -> Horner's
      - Spinal anaesthesia
      - Epidural anaesthesia
      - Direct nerve injury -> temporary or permanent neuropraxia
      - Syrinx or cavity formation in cervical cord due to injection -> paraplegia
    - - Winnie or Pippa
    - - Blocks upper trunk (inc suprascap, axillary, musculocutaneous and radial)
      - Misses medial cord and bit of posterior cord (pectoral/thoracodorsal nerves)
      - Good for lateral aspect of the arm
  - - - Training of anaesthetist
      - Minimise infection & neurotoxicity
        
        Full asepsis
        
        0.5% chlorhex spray + skin dried
      - Minimise risk of neuropraxia
        
        US
        
        Awake pt
        
        Low pressure injection
      - Avoid?
    - - Risk of hypotension causing reduced cerebral flow (especially when deck chair)
        
        Use pressors, filling etc
    - - Neuropraxias
        
        Careful positioning & padding
        
        Avoid brachial plexus stretch
    - - Minimise risk of contusion/traction
      - Minimise manipulation
  - - - Lateral 2/3rds by lat pectoral
      - Medial 1/3rd by supraclavicular nerve
- - - - High (linear - good image but poor penetration)
      - Low (curvalinear - poorer image but better penetration)
      - Wavelength needs to be smaller than what you're trying to discriminate against
    - - Only show part of image, not affect on soundwaves
    - - Increases brightness
    - - US waves are focused towards middle of screen - best lateral resolution is in the middle
  - - - Pros
        
        Can ensure needle tip
        
        Direct visualisation of whole needle, optimises placement relative to nerve in short axis
      - Cons
        
        Longer needle path (increased risk to structures, pt discomfort)
        
        Possible unrecognised tip
    - - Pros
        
        Easier for catheters as can be place parallel to nerve
        
        Familiarity
        
        Shorter distance from entry point to nerve (better comfort)
        
        May decrease nerve injury for tangential placement
      - Cons
        
        Inability to identify tip if crossed image plane
- - - - LA allergy
      - INR >1.5 or <12h post LMWH
      - Pt refusal
      - Local sepsis or infection at puncture site
    - - Systemic sepsis, poor cardiac function/fixed output
  - - - Intra neural injection
      - Damage to abdominal viscera
      - Nerve trauma
      - Retro-peritoeal haematoma
      - Psoas abscess
    - - Spinal (total)
      - Epidural spread
    - - LA toxicity
- - - - PCM 6 hourly
      - Opioid as needed
      - Nerve block (FIB) by trained person
      - Avoid NSAIDs
  - - - Anterior
        
        Posterior surface of fascia iliaca
      - Posterior
        
        Anterior surface of iliacus and psoas major muscles
      - Lateral
        
        Origin of iliacus
      - Medial
        
        Origin of psoas major
      - Nerves
        
        Femoral, LCN, obturator
    - - Supine patient
      - Asepsis
      - 50mm 22G block needle
      - High freq linear probe - transverse below inguinal ligament, lateral to femoral artery
      - Inject skin wheal of LA
      - In plane - tip under fascia iliaca
      - Negative aspirate then inject 1-2ml - check for fascia lifting and medial spread
      - Inject 30-40ml LA (ensure <2mg/kg)
  - - - Total analgesia but complex, retention, complications, coagulation
    - - Total analgesia but short lived, urinary retention, no mobilisation
- - - - Ptosis, miosis, anydrosis and enophthalmos
    - - Contralateral hyperperfusion (red 1/2 face)
        
        Due to damage of sympathetic fibres on ipsi side
  - - - T8-T12
    - - T5/6
    - - T3/4
- - - - Sensory
        
        Heel and plantar aspect of foot
      - Anatomy
        
        Midway between medial malleolus & calcaneum tip - inject posterior to tibial artery
    - - Sensory
        
        1st/2nd toe web space
      - Anatomy
        
        2-3cm distal to intermalleolar line - inject eitherside of dorsalis pedis
    - - Sensory
        
        Dorsum of foot (exc. 1/2nd webspace)
      - Anatomy
        
        Find tibial ridge, insert needle and direct toward lateral malleolus with subcut wheal
    - - Sensory
        
        Plantar aspect of 4/5th webspace & lateral foot
      - Anatomy
        
        Infiltrate subcut between lateral malleolus & achille's tendon
    - - Sensory
        
        Medial aspect of ankle
      - Anatomy
        
        Find saphenous vein anterior to medial malleolus - inject subcut from there to achilles tendon
- - - - With endoneurium injury
        
        Redcued AP distal initially, then proximal and distal, then recovery
        
        Poor prognosis if endoneurium is breached
      - With endoneurium and perineurium injury
      - Continuity of axon is lost (endoneurium, perineurium & epineurium intact)
    - - Reduced AP initially distally, then proximal and distal
      - Poor prognosis
      - Complete physiological disconnection of nerve trunk
    - - Local myelin damage with nerve intact
      - Reduced AP distal to lesion
      - Should recover within months
  - - - Manifests as wrist drop
      - Commonly due to cuffs or arm board compression
      - Runs along spiral groove of humerus where it is commonly injured
    - - Paraesthesia along palmar aspect of lateral 3.5 fingers & weakness of thumb oppostion, wrist flexion, thenar eminence wasting
      - Direct injury, invasive elbow procedures and carpal tunnel
    - - Due to compression/stretching/direct injury
      - If C5-6 roots affected - musculocutaneous, axillary and suprascap involved -> arm hands with medial rotation and pronation (Waiter's tip)
      - Course through a limited space (clavicle and 1st rib)
      - If C8-T1 then small nerves of hands affected -> claw hand
    - - Increased risk in DM
      - Paralysis of hamstrings and all muscles below the knee -> weak knee flexion & foot drop. Impaired sensation below knee (except medial aspect of leg and foot)
      - Stretch/compression/ischaemia & direct damage (esp lithotomy, frogleg & sitting positions)
    - - Most common injury (due to closeness of medial epicondyle)
      - Men > Women
      - Due to direct pressure over ulna groove or prolonged forearm flexion
      - Presents as numbness/tinging in little/ring finger
    - - Loss of sensation to front of thigh and medial aspect of leg (saphenous)
      - Weak hip flexion + loss of knee extension (difficulty climbing stairs) Decreased/absent knee jerks
      - Compression at pelvic brim in abdo surgery, ischaemia (aortic cross clamp) ~& lithotomy position with extreme abduction of thighs
    - - Knee arthoplasties
      - Loss of dorsiflexion & eversion of foot, sensory loss of anterolateral aspect of leg and dorsum of digits
      - Compression by fibular head esp lithotomy or lateral
  - - - Comorbidities (HTN, smoking, DM)
      - Pre-existing neuropathies and anatomical abnormalities (thoraci outlet issues)
    - - GA and epidural increased risk
    - - Neuro, cardiac, orthopaedics, GI surgery
    - - Hypovolaemia, dehydration, hypotension, hypoxia, electrolyte disturbance & hypothermia
- - - - Normal response to verbal stimulation
      - Airway - unaffected
      - Spont vent - unaffected
      - CVS - unaffected
    - - Purposeful response to verbal or light tactile stimulation
      - Airway - no intervention required
      - Spont vent - adequate
      - CVS - unaffected
    - - Purposeful response to repeated or painful stimulation
      - Airway - intervention may be required
      - Spont vent - may be inadequate
      - CVS - unusally maintained
    - - No response to stimuli
      - Airway - intervention normally required
      - Spont vent - frequently affected
      - CVS - may be impaired
  - - - Nitrous oxide/Oxygen 50:50 (Entonox)
      - Temazepam oral
      - Midazolam IV/oral/intranasal
      - Small single dose fentanyl IV +/- cautious midazolam IV
    - - Environment
        
        Monitoring
        
        Equiment
        
        Resus facilities & drugs
        
        Reversal agents
        
        Recovery area
      - Staffing
        
        ALS training
      - Patient consent
      - Patient selection
      - Peri-procedure
        
        Monitoring
      - Post-procedure
        
        Recovery with trained staff
        
        Discharged to responsible adult for 24h
        
        Discharge once obs stable and patient orientated
- - - - Blocks at divisions of brachial plexus
      - Risks vascular puncture & pneumothorax
      - Can block all cords here - lateral, posterior and medial
      - Doesn't get suprascapular nerve or intercostal brachial (T2 upper inner arm)
    - - 3-4cm deep and more tricky to visualise
      - Tight space so rapid onset and good for catheterisation
      - Blocks at cords - surrounds axillary artery
      - Can miss MSCN and axillary if too lateral
  - - - Easy to miss radial due to post-cystic enhancement (find conjoint tendon of LatD and TeresMaj
      - Can miss medial cutaneous nerve or forearm + intercostal brachial
      - Important to identify MSCN between biceps and coracobranchialis superiorly
- - - - Saphenous to infrapatellar
      - Obturator
      - Femoral (anterior and posterior branches)
    - - Sciatic via tibial and CPN
    - - Also supplies quads