The ESP block, like the transversus abdominis plane (TAP) or the pectoralis (PECS) and serratus plane blocks, is a fascial plane block, meaning local anesthetic is not deposited around individual nerves visible on ultrasound imaging, but is rather injected as a large volume into a plane underneath a fascia where it then spreads towards the target nerves.
The actual mechanism of action of the ESP block is a subject of ongoing research and discussion. Spread of local anesthetic into the paravertebral space, the epidural space, and the intercostal space have all been proposed as contributing to its effect.
Since the ESP block is relatively new to clinical practice, its efficacy and breadth of application are still being evaluated.
Indications
In practice, ESP blocks are mostly done between T2 and L2. Potential indications are therefore wide-ranging and include breast surgery, cardiac and thoracic surgery, abdominal surgery, urological surgery, orthopedic and spine surgery.
Block Technique
The ultrasound-guided ESP block can be performed with the patient in the prone, lateral or sitting position. The transverse processes of the vertebrae are visualized in the sagittal plane and a block needle is advanced to make contact with the appropriate transverse process, at which point local anesthetic volume is injected. Correct needle placement and injection are confirmed through spread of injectate underneath the erector spinae muscles.
Dosing
Patient weight >50 kgs:
- Single shot: 20- 30 ml ropivacaine 0.2%; double amount for bilateral blocks
- Continuous infusion/ catheter technique: 8 ml/hr ropivacaine 0.2%
Block Duration
Block duration depends on the local anesthetic chosen and the site of injection. The range of block durations reported in the literature ranges widely from 3 hours to more than 24 hours and seems to reflect different interpretations of block success (sensory block vs. lack of complaint about pain). In case longer lasting analgesia is desired, a catheter can be placed in the ESP.
Special Considerations
Possible Complications
- Infection
- Hematoma
- Pneumothorax
- Nerve damage
- Epidural injection
- Local anesthetic systemic toxicity (LAST)
Chin KJ, El-Boghdadly K. Mechanisms of action of the erector spinae plane (ESP) block: a narrative review. Can J Anaesth 2021;68(3):387–408.
Kot P, Rodriguez P, Granell M, et al. The erector spinae plane block: a narrative review. Korean J Anesthesiol 2019;72(3):209–20.