Supraclavicular block

9 min read Last updated April 9, 2026

Surgical approach (typical operations using this block)

  • Common indications: surgery on arm/forearm/wrist/hand (e.g. ORIF distal radius, tendon repairs, carpal tunnel, hand trauma washout, AV fistula formation).
  • Surgeon typically: applies tourniquet (upper arm), positions arm abducted/supinated as required, uses diathermy, may require immobility and dense sensory block.
    • Tourniquet pain can occur despite good distal block, may need supplemental analgesia/sedation or proximal block/GA.
  • Duration varies: minor hand surgery 30–90 min, trauma/ORIF often 1–2+ hours.

Anaesthetic management (typical)

  • Type of anaesthesia: Regional (supraclavicular block) ± sedation, or GA + block for analgesia.
  • Airway: usually none (spontaneous ventilation) if awake/sedated, if GA then SGA/ETT depending on aspiration risk, duration, positioning, surgical needs.
  • How painful: block provides excellent intra-op anaesthesia for distal upper limb, tourniquet can be painful, post-op analgesia usually very good for 8–18 h depending on LA and adjuncts.
  • Monitoring: standard AAGBI, IV access, resus drugs and lipid emulsion immediately available.
  • Plan for failure: top-up with distal nerve blocks (median/ulnar/radial), local infiltration, conversion to GA if needed.

Overview

  • Brachial plexus block at the level of trunks/divisions where nerves are compact (“spinal of the upper limb”).
  • Provides dense anaesthesia for upper limb distal to shoulder, often spares intercostobrachial nerve (T2) → may not cover medial upper arm/tourniquet pain.
  • Best for: elbow, forearm, wrist, hand surgery, less reliable for shoulder/proximal humerus (interscalene preferred).

Relevant anatomy (high-yield)

  • Landmarks: clavicle, sternocleidomastoid (SCM), interscalene groove, subclavian artery, first rib, pleura (cupola).
  • Brachial plexus lies lateral/posterolateral to subclavian artery, superior to first rib, superficial to pleura.
  • First rib acts as a backstop, pleura lies inferomedial—needle too medial/inferior risks pneumothorax.
  • Phrenic nerve: less frequently blocked than interscalene but still possible (hemidiaphragmatic paresis).
  • Other nearby structures: dorsal scapular artery, suprascapular artery, subclavian vein (more medial/anterior), recurrent laryngeal nerve (rare involvement).

Indications

  • Anaesthesia/analgesia for surgery distal to shoulder: elbow/forearm/wrist/hand, including trauma and day-case surgery.
  • Analgesia adjunct to GA to reduce opioids and improve recovery.
  • Facilitates manipulation/reduction and painful dressing changes.

Contraindications

  • Absolute: patient refusal, LA allergy (true IgE rare), infection at site, inability to cooperate/consent, uncontrolled bleeding/haemodynamic instability requiring immediate GA.
  • Relative: coagulopathy/therapeutic anticoagulation (follow RA-UK/ASRA principles, compressibility limited), severe respiratory disease (risk of phrenic block/pneumothorax), contralateral pneumonectomy/diaphragm palsy, pre-existing neuropathy, severe obesity/poor sonoanatomy.
  • Caution: ipsilateral recurrent laryngeal nerve palsy or contralateral vocal cord palsy (rare but potential airway compromise if bilateral).
  • Explain: aims (anaesthesia + analgesia), expected sensory/motor loss, duration, need for limb protection, possibility of failure and conversion to GA, and specific risks (pneumothorax, vascular puncture, nerve injury, LAST, diaphragmatic paresis).
  • Check: side/site marking, allergies, anticoagulants, baseline neuro exam, respiratory status, pregnancy status if relevant.
  • Equipment: ultrasound with high-frequency linear probe, sterile cover/gel, block needle, extension tubing, incremental syringe dosing, aspiration, monitoring, oxygen, suction, airway kit, intralipid 20%.

Technique (ultrasound-guided: common UK practice)

  • Position: supine, head turned away, ipsilateral arm by side, slight head-up may reduce venous engorgement, ensure comfortable access to supraclavicular fossa.
  • Probe: transverse in supraclavicular fossa, parallel to clavicle, identify subclavian artery, first rib (hyperechoic line with acoustic shadow), pleura (sliding).
  • Target: brachial plexus cluster lateral/superior to artery (“grapes/honeycomb”). Aim for spread around plexus, often at the “corner pocket” (between artery and first rib) to capture inferior trunk (ulnar distribution).
  • Needle: in-plane lateral-to-medial (commonly) to keep pleura in view, advance to perineural plane, inject small aliquots with frequent aspiration, observe circumferential spread.
  • Volume: typically 15–25 mL depending on LA choice, patient size, and desired duration, use lowest effective volume to reduce phrenic involvement and toxicity risk.
  • Adjunct blocks: intercostobrachial nerve (T2) field block for tourniquet/medial upper arm, consider ulnar/median/radial supplementation if patchy.

Local anaesthetic choices (examples, always calculate maximum safe dose)

  • Short/medium duration: lidocaine 1–2% (often with adrenaline 1:200,000) for faster onset, consider alkalinisation per local policy.
  • Longer duration: ropivacaine 0.5% or levobupivacaine 0.25–0.5% for prolonged analgesia.
  • Mixing LAs: may combine for onset + duration, but toxicity is additive, do not exceed combined maximum dose.
  • Adjuvants: dexamethasone (perineural vs IV depends on policy, evidence suggests prolongation), clonidine/dexmedetomidine (prolongation but bradycardia/sedation).

Assessment of block

  • Sensory: cold/light touch in median (index finger), ulnar (little finger), radial (dorsum thumb web space), musculocutaneous (lateral forearm).
  • Motor: wrist/finger extension (radial), finger abduction (ulnar), thumb opposition (median), elbow flexion (musculocutaneous).
  • Time: onset often 10–30 min depending on LA, do not rush to incision if incomplete—supplement early.

Complications (recognition and management)

  • Pneumothorax: pleuritic pain, dyspnoea, hypoxia, reduced breath sounds, may be delayed. Manage with oxygen, imaging, needle decompression/chest drain as indicated, involve seniors.
  • Vascular puncture/haematoma: subclavian artery/vein. Apply pressure, avoid multiple passes, consider anticoagulation status.
  • LAST: tinnitus, metallic taste, agitation, seizures, arrhythmias, cardiovascular collapse. Stop injection, call for help, airway/100% O2, treat seizures, lipid emulsion, ALS modifications.
    • Lipid (typical adult regimen): 20% intralipid 1.5 mL/kg bolus over ~1 min then 0.25 mL/kg/min infusion, repeat bolus if unstable, max ~10 mL/kg in first 30 min (follow local guideline).
  • Nerve injury: intraneural injection/high pressure, paraesthesia/pain on injection. Avoid injection against resistance, stop if pain/paraesthesia, document and follow-up.
  • Hemidiaphragmatic paresis: dyspnoea, reduced FVC, usually transient. Avoid high volumes, consider alternative approach in severe lung disease.
  • Horner’s syndrome: ptosis, miosis, anhidrosis, reassure, indicates spread to sympathetic chain.
  • Recurrent laryngeal nerve block: hoarseness, caution if contralateral palsy.

Postoperative care

  • Limb protection: sling, avoid heat/trauma, warn about insensate limb, written instructions for day-case patients.
  • Analgesia plan: regular paracetamol/NSAID (if appropriate), opioid rescue, counsel on rebound pain when block wears off (take analgesia before sensation returns).
  • Neurovascular checks if trauma/cast: pain out of proportion, paraesthesia, pallor, pulselessness → urgent surgical review (compartment syndrome not prevented by block).

Test yourself…

Talk me through how you would perform an ultrasound-guided supraclavicular block safely.

Structure your answer: preparation → anatomy/sonoanatomy → needle approach → injection strategy → safety checks.

  • Preparation: consent (including pneumothorax/LAST), IV access, monitoring, resus + lipid available, asepsis, time-out and correct side.
  • Sonoanatomy: identify subclavian artery, first rib, pleura, locate plexus lateral/superior to artery.
  • Needle: in-plane lateral-to-medial, keep tip visible, avoid medial/inferior direction toward pleura.
  • Injection: incremental 3–5 mL aliquots with aspiration, aim for circumferential spread, consider “corner pocket” to cover inferior trunk.
  • Safety: stop if pain/paraesthesia or high injection pressure, monitor for LAST, reassess block before surgery.
What are the key complications of supraclavicular block, and how would you recognise and manage pneumothorax?
  • Complications: pneumothorax, LAST, vascular puncture/haematoma, nerve injury, hemidiaphragmatic paresis, Horner’s, hoarseness (RLN), infection.
  • Recognition of pneumothorax: dyspnoea, pleuritic chest pain, hypoxia, tachycardia, reduced air entry, may be delayed post-op.
  • Immediate management: oxygen, ABC approach, call for help, consider bedside ultrasound/CXR, if tension suspected treat immediately (needle decompression) then chest drain.
A patient develops tinnitus and a metallic taste during injection. What is happening and what do you do next?
  • Likely early LAST from intravascular injection/systemic absorption.
  • Stop injecting, call for help, maintain airway and give 100% oxygen, treat seizures with benzodiazepine, avoid large propofol doses if unstable.
  • Start lipid emulsion per guideline, manage arrhythmias with ALS modifications (avoid lidocaine, cautious adrenaline doses).
Why might a supraclavicular block not cover tourniquet pain, and what can you do about it?
  • Tourniquet pain often mediated by intercostobrachial nerve (T2) and medial cutaneous nerve of arm, may be outside brachial plexus coverage.
  • Management: intercostobrachial field block in axilla/medial upper arm, systemic analgesia (opioid/ketamine), sedation, consider GA if severe or prolonged.
Compare supraclavicular with interscalene and infraclavicular approaches (indications and major risks).
  • Interscalene: best for shoulder/proximal humerus, high phrenic nerve block rate, less reliable ulnar distribution.
  • Supraclavicular: best for distal to shoulder, dense block, pneumothorax risk (reduced with ultrasound), some phrenic involvement possible.
  • Infraclavicular: good for distal arm, lower pneumothorax risk than supraclavicular, useful with catheter, deeper/closer to axillary vessels.
What ultrasound features help you avoid pneumothorax during supraclavicular block?
  • Identify first rib as hyperechoic line with shadow—acts as protective barrier, keep needle tip above rib.
  • Visualise pleural line and lung sliding, keep needle trajectory away from inferomedial pleura.
  • Maintain continuous needle tip visualisation, use shallow angle, avoid “blind” advancement.
Block failure: the patient has preserved sensation in the little finger after 20 minutes. What does this suggest and how would you manage it?
  • Suggests inferior trunk/ulnar nerve sparing—often due to inadequate spread in the “corner pocket”.
  • Management: reassess with ultrasound, consider targeted top-up in corner pocket (within safe dose limits) or perform ulnar nerve block at forearm/wrist, ensure tourniquet coverage separately.
  • If time-critical or inadequate despite supplementation: convert to GA.
How do you minimise the risk of nerve injury during peripheral nerve blockade?
  • Avoid intraneural injection: never inject with severe pain/paraesthesia, stop and reposition.
  • Use ultrasound to keep tip visible, inject small aliquots, monitor opening injection pressure (avoid high resistance).
  • Avoid deep sedation so patient can report symptoms, document baseline deficits and post-op findings.
What factors increase the risk of LAST in supraclavicular block and how can you reduce it?
  • Risk factors: high vascularity, large volumes, potent LAs, low body weight, extremes of age, pregnancy, hepatic/cardiac disease, inadvertent intravascular injection.
  • Risk reduction: calculate max dose, use lowest effective volume, incremental injection with aspiration, consider adrenaline marker dose, ultrasound guidance, avoid bilateral high-volume blocks.
A COPD patient needs wrist surgery. Would you choose a supraclavicular block? What are your considerations and alternatives?
  • Consider respiratory reserve: risk of hemidiaphragmatic paresis and pneumothorax may be poorly tolerated.
  • If proceeding: minimise volume, meticulous ultrasound technique, avoid heavy sedation, counsel regarding dyspnoea, have low threshold for alternative plan.
  • Alternatives: infraclavicular or axillary block (lower pneumothorax risk), or distal forearm blocks (median/ulnar/radial) for hand surgery, GA if necessary.

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