Regional Anaesthesia Techniques

Regional anesthesia encompasses neuraxial (spinal, epidural) and peripheral nerve block techniques that provide targeted anesthesia and analgesia for orthopaedic procedures. These techniques have become integral to Enhanced Recovery After Surgery (ERAS) protocols and multimodal analgesia.

Spinal Anesthesia (Subarachnoid Block)

Epidural Anesthesia

Combined Spinal-Epidural (CSE)

Intravenous Regional Anaesthesia (IVRA / Bier Block)

IVRA - the Bier block - is a simple, reliable technique for short distal-limb procedures (hand/forearm, and occasionally foot) that needs no nerve localisation. The topic notes that bupivacaine must never be used for IVRA; the full technique is developed here.

• Technique: site an IV cannula in the operative hand/foot; exsanguinate the limb (elevation then Esmarch bandage); inflate a double (two-cuff) tourniquet above arterial pressure; then inject dilute lidocaine or prilocaine (e.g. 0.5% lidocaine, roughly 3 mg/kg - never bupivacaine, which is cardiotoxic) through the cannula. The local anaesthetic diffuses from the vasculature into nerves, producing anaesthesia distal to the cuff within about 5-10 minutes. The proximal cuff is inflated first; once the block is established the distal cuff (now over anaesthetised skin) is inflated and the proximal cuff released to relieve tourniquet pain.
• Advantages: fast, technically easy, high success and rapid recovery - ideal for day-case carpal tunnel release, ganglion excision, or fracture manipulation.
• The critical safety issue is the tourniquet: deflation releases the sequestered local anaesthetic into the systemic circulation as a bolus, risking LAST. The cuff must therefore stay inflated for a minimum (around 20-30 minutes) regardless of how quickly surgery finishes, and at the end is deflated in cycles (deflate-reinflate) while watching for toxicity. This deflation hazard is precisely why bupivacaine is prohibited. (See the tourniquet-use topic for cuff and pressure detail.)
• Limitations: anaesthesia lasts only while the cuff is up (no postoperative analgesia), tourniquet pain limits duration to roughly an hour, and it is unsuitable when a bloodless field is needed beyond tourniquet tolerance.

WALANT (Wide-Awake Local Anaesthesia, No Tourniquet)

WALANT is a hand- (and increasingly foot-) surgery technique using local anaesthetic with adrenaline alone - no tourniquet, no sedation, no formal block - allowing fully awake, comfortable surgery.

• Technique: subcutaneous field infiltration of lidocaine (e.g. 1%) with adrenaline (e.g. 1:100,000) along the planned operative field (a tumescent approach), usually buffered with bicarbonate to reduce injection sting, then waiting about 25-30 minutes for maximal adrenaline vasoconstriction to give a near-bloodless field without a tourniquet.
• The key conceptual shift: the old teaching that adrenaline is dangerous in the fingers has been refuted - large series show lidocaine with adrenaline is safe in the digits (and phentolamine is available as a rescue reversal agent if vasoconstriction is excessive). This removed the rationale for the tourniquet and sedation in many hand procedures.
• Advantages: the patient can actively move the hand intraoperatively - invaluable for flexor tendon repair (testing repair gliding and gapping), tenolysis and tendon transfers; it avoids tourniquet pain (so no sedation), avoids general/neuraxial anaesthesia and fasting, and is efficient and low-cost (suited to minor-procedure/office settings).
• Typical uses: carpal tunnel release, trigger-finger release, flexor/extensor tendon repair, fracture K-wiring, Dupuytren surgery.

Benefits of Ultrasound

Ultrasound Techniques

Training and Competency

Common Agents

Mechanism of Action

Adjuncts

Mechanism and Risk Factors

Clinical Presentation

Management of LAST

Prevention Strategies

Reduce risk of LAST:

• Use ultrasound guidance: reduces accidental intravascular injection
• Aspirate before injection: check for blood
• Fractionated dosing: inject 3-5 mL aliquots with pauses
• Test dose: with epinephrine (will cause tachycardia if IV)
• Maximum dose limits: calculate and respect limits
• Avoid bupivacaine for IVRA: use lidocaine or prilocaine
• Communicate with patient: ask about symptoms during injection

Absolute Contraindications

Relative Contraindications

Consider risks vs benefits:

• Pre-existing neurological deficit (medicolegal)
• Sepsis (bacteremia risk of seeding)
• Severe spinal deformity (difficult technique)
• Prior spine surgery at level (altered anatomy)
• Prophylactic anticoagulation (timing critical)

Anticoagulation Guidelines

Neuraxial anesthesia timing:

Catheter removal timing:

• Remove catheter before restarting anticoagulation
• Wait same interval as for block placement after removal
• Observe for 4 hours after removal for signs of hematoma

Complications by Block Type

OrthoVellum is a worldwide resource: regional anaesthesia is practised on every continent, and the major society guidance is largely convergent. The differences a candidate is most likely to be examined on relate to anticoagulation timing, LAST rescue protocols, and the local availability of ultrasound and lipid emulsion.

Epidemiology and burden

• Local anaesthetic systemic toxicity (LAST) is the most feared complication of regional anaesthesia. Contemporary registry and audit data place clinically apparent LAST in the low single digits per 10,000 peripheral nerve blocks, with severe cardiac events rarer still.
• Permanent peripheral nerve injury after blockade is rare (of the order of 0.02-0.04% at long-term follow-up), with most postoperative neurological deficits being transient and multifactorial (surgery, tourniquet, positioning).
• Adoption of ultrasound guidance has risen to near-universal in high-resource settings; nerve stimulation and landmark techniques remain important where ultrasound is unavailable.

Major guidelines, side by side

LAST rescue: the global consensus

• 20% lipid emulsion is the agreed first-line therapy worldwide and should be stocked wherever local anaesthetic is injected in potentially toxic doses.
• Bolus 1.5 mL/kg then infusion 0.25 mL/kg/min, with repeat boluses for persistent instability and an approximate upper limit of 10-12 mL/kg.
• Reduce adrenaline dosing, avoid vasopressin, calcium channel blockers and beta-blockers, and anticipate prolonged resuscitation with consideration of cardiopulmonary bypass in refractory arrest.

Registry and practice variation

• Regional anaesthesia is not implant-based, so it is not tracked by the arthroplasty joint registries (NJR, AOANJRR, AJRR, SHAR); registry insight instead comes from national audit projects and adverse-event databases.
• High- vs limited-resource settings: where ultrasound machines, single-use block needles or lipid emulsion are scarce, nerve stimulation and landmark spinal anaesthesia remain mainstays, and drug selection favours cheaper agents (lidocaine, bupivacaine) over ropivacaine/levobupivacaine.
• ERAS integration is global: regional anaesthesia is a cornerstone of enhanced recovery for arthroplasty everywhere, with motor-sparing combinations (ACB + IPACK for TKA; PENG or fascia iliaca for hip; interscalene for shoulder) reducing opioid use and enabling early mobilisation.

Regional anesthesia in orthopaedics includes neuraxial (spinal/epidural) and peripheral nerve blocks for upper limb (interscalene for shoulder, supraclavicular/infraclavicular for elbow/forearm, axillary for hand) and lower limb (femoral, adductor canal, sciatic, popliteal). Ultrasound guidance is now standard, reducing block failure and vascular puncture compared with nerve stimulation. The critical complication is LAST (Local Anesthetic Systemic Toxicity), which presents with CNS symptoms first (perioral numbness, tinnitus, seizures) before cardiovascular collapse - treatment is 20% lipid emulsion (1.5 mL/kg bolus). Adductor canal block is preferred over femoral nerve block for TKA as it preserves quadriceps strength and enables early mobilisation.

Regional anesthesia is a cornerstone of modern orthopaedic perioperative care, offering superior analgesia, reduced opioid consumption, and facilitation of early mobilization. The evolution from landmark-based techniques to ultrasound-guided approaches has dramatically improved safety and efficacy.

Key exam points:

• LAST is a life-threatening complication treated with lipid emulsion 20%
• Ultrasound guidance is now standard of care for peripheral nerve blocks
• Motor-sparing blocks (ACB, IPACK, PENG) enable ERAS protocols and same-day mobilization
• Block selection must match surgical site and patient goals
• Anticoagulation timing is critical for neuraxial safety

Future directions include development of novel motor-sparing blocks, longer-acting local anesthetics, and integration of continuous catheter techniques with ambulatory surgery protocols.