Erector Spinae Plane Block

• ESPB achieves a block of the posterior, lateral, and anterior thoracic wall
• Retrospective cohort studies have demonstrated increased respiratory function, reduced pain scores, and reduced opioid consumption when administered to patients with multiple posterior rib fractures. No complications were demonstrated

Anatomy

• The “erector spinae” is a group of muscles that run bilaterally from the skull to pelvis/sacral region, and from spinous to transverse processes, extending to the rib
• The aim to inject local anaesthetic (LA) into the fascial plane that runs between the muscle and the transverse process

• LA spreads anteriorly to the paravertebral space and laterally to reach intercostal nerves, and spreads along the plane in a craniocaudal manner, covering 3-4 levels above and below

Indications

• Two or more acute posterior, posterolateral, or lateral rib fractures
• Opioid analgesia and/or oxygen requirement

Contraindications

• Absolute:
  • LA allergy
  • Risk of LA toxicity (e.g. if other regional anaesthesia such as femoral nerve block already performed)
  • Localised infection att site
• Relative:
  • Inadequate assessment of sonoanatomy (e.g. obese patient)

In patients with isolated anterior or anterolateral rib fractures, a serratus anterior plane block (SAPB) may be more appropriate.

Preparation

• Patients must be cardiac monitored in a resuscitation bay with IV access
• Preferred position is the patient sitting on the edge of the bed leaning forwards, with the machine on the opposite side of the bed in line of sight
• Prepare the thoracic wall with 2% chlorhexidine solution
• Dilute 20ml of 0.75% ropivacaine (150mg) with 20ml normal saline for a total volume solution of 40ml (alternatively 40ml of 0.25% levobupivacaine, adhering to safe weight-based LA dosing)
• STOP before you block – confirm correct side of block

Sonoanatomy

• High frequency linear probe (musculoskeletal preset) is placed in a parasagittal longitudinal position, around 3cm from the midline
• Identify the ribs and adjacent pleural line, and set your depth such that the pleural line and lung are in the bottom third of your image
• Move the probe medially — transverse processes will appear more square-like, and the pleural line with disappear

Technique

• Using an in-line cephalic approach, aim to contact the corner of the transverse process to “lift off” the fascia
• After contact, inject 40ml of LA in 5-10ml increments. You should visualise the erector spinae muscle “peeling” off the top of the transverse process
• You can follow the spread of injectate with your needle tip during or after administration