Erector Spinae Plane (ESP) Block - ARiRA Pro Tips
Indications
The erector spinae plane (ESP) block is a versatile regional anaesthesia technique used for thoracic, abdominal, and lumbar analgesia. It is commonly performed for rib fractures, thoracic surgery, breast surgery, abdominal procedures, and lumbar spine surgeries. The ESP block provides effective pain relief by blocking the dorsal and ventral rami of the spinal nerves, making it useful for both acute and chronic pain management.
Anatomy
The erector spinae muscles (Iliocostalis, Longissimus, and Spinalis) extend longitudinally along the vertebral column. This block targets the fascial plane between the erector spinae muscle group and the transverse processes of the vertebrae, allowing local anaesthetic to spread cranially and caudally. The injectate affects the dorsal and ventral rami of the spinal nerves, along with the sympathetic chain, providing multilevel somatic and visceral analgesia.
Patient Positioning
Position the patient sitting or lateral, depending on patient comfort and operator preference. In the sitting position, the patient should be asked to slightly flex forward to widen the intervertebral spaces. The lateral position may be preferable for patients under sedation or general anaesthesia. The ultrasound probe is placed longitudinally, over the paraspinal region, at the level of the desired thoracic or lumbar vertebra.
Ultrasound Technique
A high-frequency linear probe is used for thoracic ESP blocks, while a curvilinear probe may be needed for lumbar-level procedures. The transverse processes serve as bony landmarks, with the erector spinae muscle seen as superficial to them. The target site for injection is the plane between the muscle and transverse process, where the anaesthetic spreads effectively. Adjusting depth and gain settings optimises visualisation of the fascial plane.
Needle Insertion
The in-plane technique is preferred, with the needle inserted in a cephalad-to-caudal or caudal-to-cephalad direction, depending on operator comfort. Hydrodissection with saline enhances needle placement within the fascial plane. The needle tip should always remain above the transverse process, avoiding deeper penetration towards the pleura.
Injection Volume
A volume of 20–30 mL of local anaesthetic is typically used for thoracic and lumbar ESP blocks, ensuring adequate multilevel spread. In the thoracic region, approximately 2.5 mL per vertebral level is typically sufficient due to the anatomical spread of injectate, while in the lumbar region, around 5 mL per vertebral level is required to account for the larger vertebrae and muscle mass.
Maximising Block Effectiveness
The ESP block provides indirect visceral and somatic analgesia, but its efficacy depends on local anaesthetic spread along the fascial plane. To ensure success:
Confirm the correct fascial plane by observing the hydrodissection effect during the test injection.
Maintain a steady needle angle to avoid puncturing deeper structures.
Use a sufficient volume to enable cranial and caudal spread of local anaesthetic.
Minimising Complications
The ESP block is considered safe, with a low risk of vascular puncture, pneumothorax, or nerve injury. However, precautions should be taken to:
Confirm needle tip placement using real-time ultrasound guidance.
Avoid pleural puncture by ensuring that the needle remains superficial to the transverse process.
Reduce the risk of LAST (Local Anaesthetic Systemic Toxicity) by aspirating before injection, using incremental injections (3–5 mL at a time) and calculating the safe total dose of local anaesthetic, which can be used based on the patient's weight.
Erector Spinae Plane (ESP) Block – FAQs
Q: How does the ESP block differ from paravertebral and epidural blocks?
A: The ESP block provides multilevel analgesia similar to the paravertebral and epidural blocks, but it is performed more superficially, reducing the risk of complications such as hypotension or spinal cord injury. Unlike the paravertebral block, which requires direct injection near the spinal nerves, the ESP block delivers local anaesthetic into a fascial plane, allowing passive spread to multiple dermatomes.
Q: How does the local anaesthetic reach the target area for the ESP block?
A: In the Erector Spinae Plane (ESP) block, local anaesthetic spreads within the fascial plane between the erector spinae muscle and the transverse processes of the vertebrae. From this site, the anaesthetic reaches the spinal rami through multiple pathways:
Cranial-Caudal Spread: The local anaesthetic travels along the longitudinal fascial plane, covering multiple thoracic or lumbar dermatomes.
Anterior Diffusion through Intertransverse Connective Tissue: The anaesthetic moves medially, penetrating the intertransverse connective tissue, allowing it to reach the paravertebral space, where the dorsal and ventral rami of the spinal nerves are located.
Spread to the Paravertebral Space: The fascial continuity between the erector spinae plane and the paravertebral space enables the anaesthetic to block the ventral rami (for somatic analgesia) and dorsal rami (for posterior thoracic/lumbar analgesia).
Effect on the Sympathetic Chain: In some cases, the anaesthetic extends further to the sympathetic chain, contributing to visceral pain relief and reducing sympathetic tone.
Q: What are the key advantages of the ESP block?
A: The ESP block is a safe, simple, and effective alternative to more invasive neuraxial techniques. Key advantages include:
Lower risk of complications such as pneumothorax, vascular puncture, and nerve injury.
Multilevel analgesia with a single injection, covering both somatic and visceral pain.
Suitable for anticoagulated patients where epidural or paravertebral blocks are contraindicated.
Longer-lasting pain relief compared to infiltration techniques, with the option for catheter placement.
Q: Is the ESP block better than an epidural?
A: The ESP block is less invasive than an epidural, making it safer for patients on anticoagulation therapy. While an epidural provides a denser block, the ESP block offers multilevel analgesia without the risk of hypotension or motor blockade, making it suitable for thoracic, abdominal, and lumbar procedures.
Q: How long does it take for the ESP block to work?
A: The onset of action depends on the local anaesthetic used. Lidocaine provides rapid onset (5–10 minutes), while bupivacaine and ropivacaine may take 15–30 minutes for full effect. The block's duration can be extended with adjuvants like dexamethasone or with the placement of a catheter connected to a local anaesthetic infusion pump.
Q: Can the ESP block be used for rib fractures?
A: Yes, the ESP block is highly effective for rib fractures, particularly when performed at the T4–T6 levels. It provides analgesia without affecting respiratory function, unlike paravertebral or intercostal blocks, which may carry a higher risk of pneumothorax.
Q: What is the best level for performing an ESP block?
A: The ESP block can be performed at multiple levels along the spine, depending on the surgical site and pain distribution:
T2–T6: Ideal for thoracic surgery, rib fractures, and breast surgery.
T7–T9: Used for abdominal wall procedures such as laparotomies and hernia repairs.
L1–L4: Provides lumbar analgesia, commonly used in hip and spine surgery.
The choice of level is guided by ultrasound visualisation and dermatomal pain coverage.
Q: How long does the ESP block last?
A: The duration depends on the local anaesthetic used. Typically:
Lidocaine: 2–3 hours for short procedures.
Ropivacaine/Bupivacaine: 8–18 hours for longer analgesia.
Adjuvants such as dexamethasone can extend the duration of the block by several hours.
For prolonged analgesia, a continuous infusion via catheter can maintain the effect for 48–72 hours.
Q: Can an ESP block be used for chronic pain management?
A: Yes, the ESP block is increasingly used in chronic pain syndromes, including post-thoracotomy pain, post-mastectomy pain, and chronic lower back pain. It can also be used for neuropathic pain conditions, particularly when conventional treatments fail.
Q: Can the ESP block be used in paediatric patients?
A: Yes, the ESP block is safe and effective in paediatric anaesthesia, particularly for thoracic and abdominal surgery. It offers a less invasive alternative to epidurals, reducing the risk of hypotension and motor blockade while still providing long-lasting analgesia. The dose must be adjusted based on weight and age, ensuring safe local anaesthetic limits are followed.
Q: When is an ESP block contraindicated?
A: Absolute contraindications include patient refusal, local infection at the injection site and allergy to local anaesthetics. Relative contraindications include severe spinal deformities that may interfere with local anaesthetic spread and patients with pre-existing neurological deficits where nerve function assessment is crucial postoperatively.
Q: Does the ESP block affect motor function?
A: No, the ESP block is primarily sensory, meaning it does not cause motor blockade. This makes it particularly useful for postoperative pain management, where preserving mobility is important for early recovery and physiotherapy.
Q: What is the success rate of an ESP block?
A: The success rate of the ESP block is high, with studies reporting analgesia effectiveness in 85–95% of cases. Its success depends on accurate ultrasound-guided needle placement, volume of local anaesthetic, and spread within the fascial plane.
Q: Can the ESP block be performed bilaterally?
A: Yes, the ESP block can be done bilaterally, particularly for abdominal surgery. However, caution should be taken with local anaesthetic dose limits to avoid LAST (Local Anaesthetic Systemic Toxicity).
Q: Is an ESP block painful to perform?
A: Most patients tolerate the ESP block well. Using a small-gauge needle for skin infiltration, ensuring gentle hydrodissection, and using ultrasound guidance can help minimise discomfort during the procedure.
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This content has been specifically tailored for healthcare professionals, focusing on unique strategies to optimise safety and efficacy during supraclavicular brachial plexus block procedures. Always apply clinical judgment tailored to individual patient needs.