Anaesthesia - Haematoma block

Reduction after a haematoma block can still be very painful

It is not recommended as a sole modality of pain relief for fracture reduction

It may be considered as an adjunct where procedural sedation is contraindicated


Forearm or distal radius fracture requiring reduction

Contraindications (absolute in bold)

Open fracture

Allergy to local anaesthetic agents


Bier's block

Procedural sedation (parenteral or inhalational)

General anaesthesia with reduction in operating theatre

Informed consent

Medical emergency

Consent is not required if the patient lacks capacity or is unable to consent

Brief verbal discussion is recommended if the situation allows


Verbal consent

Less complex non-emergency procedures with low risk of complications

Potential complications

Failure (ineffective analgesia)

Neurovascular injury

Infection (cellulitis, osteomyelitis)

Compartment syndrome

Procedural hygiene

Standard precautions

Aseptic non-touch technique

PPE: sterile gloves


Any clinical area suitable for fracture reduction and cast application


Procedural clinician

Assistant required for fracture reduction


10ml syringe

Drawing up needle

23g needle for the injection

High-frequency linear transducer and ultrasound (optional)


Supine with forearm and palm down on a supportive surface


10-15ml lignocaine 1% (without adrenaline) up to maximum of 3mg/kg

Sequence (without ultrasound)

Review fracture X-ray noting dorsal pattern and location of fractured periosteum

Palpate the fracture (‘bony step off’) on the dorsum of the wrist

Insert the needle at the fracture site aspirating the needle as it advances

Confirm placement in the fracture haematoma with flashback of blood

Inject 10-15ml lignocaine (and aspirated blood) into the fracture site

Sequence (with ultrasound)

Review fracture X-ray noting dorsal pattern and location of fractured periosteum

Trace the radius longitudinally with the US, noting the break in the cortex

Insert the needle using ultrasound in plane technique through the break in cortex into the fracture space

Confirm placement in the fracture haematoma with flashback of blood and inject 10ml of lignocaine

Consider tracing the ulnar laterally (associated styloid fracture) injecting 5ml lignocaine if fracture present

Post-procedure care

Remove needle and dress with adherent waterproof dressing

Proceed with reduction after 10 minutes when the block is fully in effect


A common error is to perform this procedure too soon after injection (5-10 minutes is required)

Ultrasound use is recommended for impacted multi-fragment fractures with loss of palpable landmark

If the injury is several hours old, the haematoma may not provide flashback on aspiration

Analgesia with lignocaine alone may last for several hours


The haematoma block is a technique to inject a local anaesthetic solution into the haematoma between the fractured bone fragments. The dorsal aspects of arm contain fewer neurovascular structures and is preferred.

Hematoma blocks of the distal forearm are considered safe in children and adults, and with systemic analgesia, can often provide the conditions needed to reduce a fracture without procedural sedation. Generally, intravenous regional anaesthesia (Bier’s block) provides better analgesia during fracture manipulation, enabling better reduction of the fracture, but with additional risks from IV anaesthetic injection.

Peer review

This guideline has been reviewed and approved by the following expert groups:

Emergency Care Institute

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