Linking To And Excerpting From Erector Spinae Plane Block [ESP Block] From StatPearls

In this post, I link to and excerpt from Erector Spinae Plane Block [ESP Block], by Krishnan S, Cascella M., last Update: April 30, 2022. From StatPearls Publishing.

All that follows is from the above resource.

Continuing Education Activity

Erector spinae plane block is a relatively novel approach to pain management for a variety of surgical procedures, as well as for acute and chronic pain. It is performed as a single injection block, or a catheter is placed for continued relief, and the procedure is most often performed with ultrasound guidance. As the erector spinae plane block is a relatively new procedure, the vast majority of information about the block is from case reports and anecdotal experience. This activity reviews the indications, contraindications, potential complications, personnel required, and technique to perform the block in a clinical setting while highlighting the role of an interprofessional team in managing the care of patients who will receive or who have received this block.

Introduction

The erector spinae plane (ESP) block is a newer regional anesthetic technique that can be used to provide analgesia for a variety of surgical procedures or to manage acute or chronic pain. The technique is relatively easy to perform on patients, and it is performable with minimal or no sedation in the pre-operative holding area. The ESP block can is possible either using a single-injection technique or via catheter placement for continuous infusion. The first report of the successful use of this procedure was in 2016; the block was used to manage thoracic neuropathic pain in a patient with metastatic disease of the ribs and rib fractures.[1] Since then, the block has been reported to have been used successfully in a multitude of procedures including Nuss procedure, thoracotomies, percutaneous nephrolithotomies, ventral hernia repairs, and even lumbar fusions.[2][3][4][5][6] As this is a relatively novel procedure, ESP block is still in numerous trials with many different types of surgical procedures, and various prospective studies are ongoing.

Anatomy and Physiology

ESP block is most often performed using an in-plane ultrasound-guided technique. It is a paraspinal fascial plane block in which the needle placement is between the erector spinae muscle and the thoracic transverse processes, and a local anesthetic is administered, blocking the dorsal and ventral rami of the thoracic and abdominal spinal nerves.[1] This blockage of the dorsal and ventral rami of the spinal nerves helps to achieve a multi-dermatomal sensory block of the anterior, posterior, and lateral thoracic and abdominal walls.

There is a hypothesis that the multi-dermatomal sensory block is due to the cranial and caudal spread of the injected local anesthetic. This spread is aided by the thoracolumbar fascia, which extends across the posterior thoracic wall and abdomen.[5] Chin et al. documented the cadaveric spread of local anesthetic and noted that, radiologically, the local anesthetic spread extended 3 or 4 levels cranially and caudally from the site of injection.[5] The reported mechanism of action is the diffusion of the injected local anesthetic through the connective tissues and towards the spinal nerve roots. [7] A more recent study described the transforaminal and epidural spread of the local anesthetic during ESP block using MRI. The authors noted that ESP block might be advantageous to other thoracic interfascial plane blocks because of this spread and the resultant abdominal visceral analgesia.[8]

Indications

The ESP block can be used to deliver regional analgesia for a wide variety of surgical procedures in the anterior, posterior, and lateral thoracic and abdominal areas, as well as for the management of acute and chronic pain syndromes. The vast majority of indications for ESP block have their basis in case reports and anecdotal clinical experience.

Contraindications

Infection at the site of injection in the paraspinal region or patient refusal, are absolute contraindications for performing an ESP block.

Anticoagulation may be a relative contraindication to ESP block, although there are no specific guidelines. The most recent 2018 ASRA consensus statement does not specifically address paraspinal blocks and anticoagulation.

Equipment

  • Chlorhexidine gluconate
  • Sterile gloves, mask, hair cover
  • Convex or curvilinear ultrasound probe with sterile probe cover and gel
  • Standard epidural catheter tray with a 3-ml syringe with lidocaine 1% on a 25-gauge needle,18-gauge Tuohy needle, and an epidural catheter (in the case of continuous infusion)
  • ESP block local anesthetic solution (0.25% bupivacaine or 0.5% ropivacaine 20 to 30ml)

Personnel

An anesthesiologist with regional anesthesia experience is preferable. An additional clinician, which can be a nurse or physician, should be available to assist.

Preparation [And Monitoring]

An informed consent, including risks and benefits of the procedure, should be performed before carrying out an ESP block. A peri-procedural “timeout” should be performed to confirm the type of procedure, side, and location of the procedure, and to ensure that there are no contraindications.

Standard patient monitoring should be in place, including continuous ECG monitoring, pulse oximetry, and blood pressure measurement in at least 5-minute intervals. Intravenous access should be obtained, and resuscitation equipment, including vasopressors/medications for local anesthetic toxicity and intubating equipment, should be nearby.

Patients should have prepping performed with chlorhexidine gluconate, and sterile conditions maintained throughout the procedure. Sterile gloves and surgical cap and mask should are necessary, and the ultrasound probe placed into the sterile ultrasound probe cover for imaging.

Technique

The ESP block is most often performed between the T5-T7 paraspinal levels, but it can be performed at lower levels as well. The curvilinear ultrasound transducer should be placed in a cephalocaudal orientation over the midline of the back at the desired level. The probe should then slowly be moved laterally until the transverse process is visible. The transverse process requires differentiation from the rib at that level. The transverse process will be more superficial and wider, while the rib will be deeper and thinner. Upon verification of the transverse process, the trapezius muscle, rhomboid major muscle (if performing at T5 level or higher), and erector spinae muscle should be identified superficial to the transverse process. The Tuohy needle should be inserted superior to the ultrasound probe using an in-plane approach in the cephalad to caudal direction. The bevel of the Tuohy needle should point posteriorly and inferiorly, and advance under ultrasound guidance through the trapezius muscle, rhomboid major muscle, and erector spinae muscle and towards the transverse process; once the needle tip is below the erector spinae muscle, a small bolus of local anesthetic should be given through the Tuohy needle. The erector spinae muscle should be visualized, separating from the transverse process. This separation from the transverse process confirms the proper needle position. The local anesthetic should then be injected in 5 ml increments, with aspiration after every 5 ml to prevent intravascular injection. Between 20 and 30 ml of 0.25% bupivacaine or 0.5%, ropivacaine should be used.  After injecting 10 to 20 ml of the local anesthetic solution, the catheter can thread easily into that space. It is prudent to thread 5 to 7 cm of the catheter into the space to avoid inadvertent dislodgement of the catheter. The last 10 to 20 cc can then be injected through the catheter after confirming that the catheter is not intravascular. The ultrasound probe can be moved caudally during injection into the catheter and, often, the local anesthetic can be seen spreading caudally from the catheter.

Complications

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