ESP in Anesthesia: Erector Spinae Plane Block
ESP stands for Erector Spinae Plane block, a fascial plane regional anesthesia technique where local anesthetic is injected into the space between the erector spinae muscle and the transverse process of the vertebrae to provide perioperative analgesia.
What It Is
The ESP block is a relatively novel interfascial plane block that has become widely adopted in modern anesthesia practice 1. The technique involves depositing local anesthetic (typically bupivacaine or ropivacaine) in the tissue plane deep to the erector spinae muscles, where it spreads to block both dorsal and ventral rami of spinal nerves 2.
Clinical Applications
According to the 2026 ASA Practice Guidelines, the ESP block is now recommended across multiple surgical categories 1:
Cardiothoracic Surgery
- Open cardiac surgery with sternotomy (CABG, valve replacements)
- Minimally invasive procedures (VATS, lobectomy, esophageal surgery)
- Used as single-injection or continuous catheter technique
Abdominal Surgery
- Open procedures: hysterectomy, liver resection, nephrectomy, gastrectomy, colorectal surgery
- Minimally invasive: cholecystectomy, bariatric surgery, appendectomy
- Covers both upper and lower abdominal incisions
Truncal Surgery
- Radical mastectomy and breast surgery
- Part of multimodal analgesia protocols
Vertebral Surgery
- Lumbar spine procedures
- Reduces postoperative opioid consumption and pain scores 3
Mechanism of Action
The primary mechanism is direct neural blockade through physical spread of local anesthetic to the paravertebral space and adjacent neural structures 2. The block affects:
- Dorsal rami (consistently blocked)
- Ventral rami of spinal nerves (variable spread)
- Epidural space (less common, but can occur unintentionally) 4
The spread pattern is somewhat unpredictable, which is both a limitation and explains its broad analgesic coverage 5.
Technical Considerations
Administration methods:
- Ultrasound-guided (traditional approach by anesthesiologists)
- Fluoroscopy-guided (emerging technique, average 1.2 minutes to perform) 6
- Can be performed as single-injection or continuous catheter
Local anesthetics used:
- Bupivacaine (most common)
- Ropivacaine
- Levobupivacaine (less frequent)
Clinical Benefits
The ESP block provides:
- Reduced opioid consumption at 24 hours postoperatively (8.70-18.69 mg morphine equivalent reduction) 3
- Decreased pain scores at 12 and 24 hours (though clinically modest, typically <1 point on pain scales)
- Lower incidence of PONV 3
- Reduced need for additional analgesics
Important Caveats
Unpredictable spread: The anatomical complexity of the erector spinae fascia means local anesthetic distribution can be variable and unpredictable 5. This limits the ability to guarantee consistent dermatomal coverage.
Unintended epidural spread: Cases of inadvertent epidural anesthesia have been reported with unilateral ESP blocks, causing unexpected bilateral effects 4.
Evidence quality: While widely used, most research provides low-to-moderate quality evidence with high heterogeneity in outcomes 3. The 2026 ASA guidelines represent the strongest endorsement to date, incorporating data from over 100 randomized trials across surgical categories 1.
Role in multimodal analgesia: The ESP block should be integrated into comprehensive multimodal protocols that include non-opioid analgesics (acetaminophen, NSAIDs, COX-2 inhibitors) rather than used as monotherapy 1.