Overview of Erector Spinae Plane Block
The erector spinae plane (ESP) block is a newer type of regional anesthesia technique—that is, a method of numbing a specific area of the body—that can be used for pain relief during various types of surgeries or in managing sudden or long-term pain. It is relatively straightforward for doctors to perform this technique on patients and it can even be done with little to no sedation before surgery, even right there in the pre-surgery holding area.
There are two ways doctors can administer the ESP block: they can either give a single injection or place a catheter—a thin, flexible tube—for a steady flow of medication. The very first time this procedure was usеd successfully was reported in 2016; it was used to manage chest-related nerve pain in a patient with cancer spread to the ribs and fractures in the ribs.
Since then, the block has been used successfully in a variety of procedures including the Nuss procedure (which corrects a chest wall deformity), thoracotomies (chest surgeries), percutaneous nephrolithotomies (a method to remove kidney stones), ventral hernia repairs, and even lumbar fusions (a surgery to join two or more vertebrae together).
Since the ESP block is still a relatively new procedure, many more tests are being done on how it can be used in different types of surgical procedures, and several scientific studies are still underway.
Anatomy and Physiology of Erector Spinae Plane Block
An ESP block is a procedure usually carried out with the help of ultrasound for precision. It’s a type of pain-relief method wherein a needle is placed between specific muscles in the back (erector spinae muscle) and parts of the backbone (thoracic transverse processes). Here, a local pain-numbing medication is given, which interferes with the ability of certain nerves (dorsal and ventral rami of the thoracic and abdominal spinal nerves) to send pain signals. This effect can help numb a wide-ranging area of skin overlying the chest and belly, from the front to the back and sides.
Scientists believe that the broad range of numbing achieved is due to how the painkiller spreads within the back. The spreading ability is helped by a structure called the thoracolumbar fascia, which crosses the back of the chest and belly. In studies carried out on cadavers, the numbing medication was observed to spread both above and below the injection site, thus affecting even more area. The numbing effect is believed to work via diffusion of the medication seeping into areas of connective tissue and reaching the nerve roots.
A recent study looked at how the medication spreads within the body during an ESP block with MRI scans. The researchers found that an ESP block could be more beneficial than other similar procedures. One of the reasons for this is its ability to spread and provide pain relief even to the abdominal organs.
Why do People Need Erector Spinae Plane Block
The ESP (Erector Spinae Plane) block is a method used for providing pain relief in many types of surgeries. These surgeries can be located in the front or back of the chest or stomach area, and even the side parts. This technique is also useful in managing sharp, sudden (acute) pain or long-lasting (chronic) pain. Most of the times, doctors decide to use this ESP block based on individual case studies or from their own past experiences with patients.
When a Person Should Avoid Erector Spinae Plane Block
An ESP block, which is a type of pain management procedure, cannot be performed if there’s an infection in the area of the back where the injection needs to be given, or if the patient refuses the procedure. These are known as absolute contraindications, which means it’s simply not safe to proceed with the treatment.
Having an anticoagulation condition, which means the blood is thinner and doesn’t clot normally, may make the procedure more risky. Yet, there are no clear rules about whether patients with this condition can have an ESP block or not. In fact, the latest advice given by the ASRA – a respected organization in the field – in 2018 didn’t give specific guidance on this issue.
Equipment used for Erector Spinae Plane Block
Here’s a list of the materials required for the procedure:
* Chlorhexidine gluconate: This is an antiseptic solution to clean the skin and prevent infection.
* Sterile gloves, mask, hair cover: These are to ensure that the environment remains sterile while conducting the procedure to prevent any infection.
* A convex or curvilinear ultrasound probe with a sterile cover and gel: This tool is used to make internal images of the body which guides the doctors during the procedure.
* Standard epidural catheter tray: This tray has all the equipment needed for an epidural, which is a type of anesthesia. The tray contains a small 3-ml syringe filled with lidocaine 1% (a numbing medication) on a 25-gauge needle, an 18-gauge Tuohy needle (a specific type of needle used in epidurals), and an epidural catheter (a thin tube inserted into the space around your spinal nerves).
* ESP block local anesthetic solution: This solution consists of either 0.25% bupivacaine or 0.5% ropivacaine. It numbs the area and is usually given as 20 to 30ml. This is especially used for continuous pain relief infusion.
Who is needed to perform Erector Spinae Plane Block?
It’s best if the doctor who gives the anesthesia (helps you sleep or numbs a part of your body) during the procedure has experience in “regional anesthesia.” This is a type of anesthesia that only affects a specific area of your body, allowing you to be awake but not feel pain in that area. There should also be another medical person, like a nurse or a different doctor, available to help out if needed.
Preparing for Erector Spinae Plane Block
Before carrying out an ESP block, which is a type of medical procedure, it’s important to fully discuss it with the patient. This discussion should include what the procedure entails, as well as any potential risks and benefits. This is referred to as “informed consent”. Furthermore, it is crucial to double-check the procedure details, the location where it will be done, and making sure there are no reasons the procedure shouldn’t take place. This check is known as a “peri-procedural timeout”.
While the procedure is occurring, it’s important to continuously monitor the patient’s health. This includes regularly checking their heart activity with an EKG, measuring the amount of oxygen in their blood, and regularly measuring their blood pressure. Medical staff also need to ensure the patient has a secure intravenous line, or IV, for giving medications and fluids. Resuscitation equipment and specific medications for managing any local anesthetic reactions or complications should be readily available.
To make sure the procedure site is as clean as possible, patients will be cleaned with a special soap called chlorhexidine gluconate. Every step of the way, the procedure area should remain as sterile as possible. The medical team will wear sterile gloves, a surgical cap, and a mask. The imaging device, known as an ultrasound probe, will also be covered with a sterile cover to ensure cleanliness.
How is Erector Spinae Plane Block performed
The ESP block is a technique often used to manage pain, and it’s usually done between the levels of T5-T7 of the spine (found in the mid-back area), although it can be done at lower levels too. For this technique, a special ultrasound device is used to guide the procedure. So, let’s imagine the midline of the back is the starting point. The doctor will then slowly slide the ultrasound device sideways until they can see a structure called the transverse process on the ultrasound screen.
The transverse process is a small bony projection off the side of each vertebra, and it’s important for the doctor to identify it correctly and to differentiate it from the rib at that level. It’s also key to distinguish between the trapezius muscle (the large muscle on the back that extends down the neck), the rhomboid major muscle (located underneath the trapezius, but can be visible if the ESP block is performed at T5 level or higher), and the erector spinae muscle (a group of muscles running vertically along each side of the vertebral column), which are found just above the transverse process.
Then the doctor will insert a special needle, called a Tuohy needle, above the ultrasound device. The needle is directed from the top (the head) to the bottom (the tailbone), aiming the needle towards the transverse process and advancing it through the mentioned muscles. The doctor will inject a small dose of local anesthetic through the needle when its tip is below the erector spinae muscle. In response to this injection, the erector spinae muscle should be seen separating from the transverse process on the ultrasound screen. This separation shows that the needle is in the right position.
After confirming the needle’s correct positioning, the doctor will further inject the local anaesthetic in five-milliliter doses, making sure to draw back the plunger after each dose to avoid accidentally injecting into a blood vessel. They usually use between 20 and 30 milliliters of 0.25% bupivacaine or 0.5% ropivacaine.
After injecting half of the anesthetic solution, the doctor can easily thread a small catheter (a thin tube) into that space. 5 to 7 centimeters of the catheter are generally inserted, to prevent the catheter from unintentionally slipping out. After making sure the catheter isn’t in any blood vessels, the doctor will inject the remaining 10 to 20 milliliters of the anesthetic through the catheter. They can slide the ultrasound device downwards during this injection, which often allows them to see the local anesthetic spreading downwards from the catheter.
Possible Complications of Erector Spinae Plane Block
Issues after getting a medical injection are not common as the needle is placed far from critical areas such as the lining of the lungs (pleura), major blood vessels, and spinal cord. However, potential problems could include infections near where the needle was inserted, allergic reactions or toxicity from the local anesthetic, injury to the blood vessels or the pleura, a punctured lung (pneumothorax), or the injection not working as intended.
There aren’t many studies on the rate and the severity of these complications, so more research, like randomized controlled trials (studies where people are randomly put into one of two or more groups) are needed to confirm how safe and effective this method is. Recently, a study that uses evidence from other studies to come to its conclusions found only four suitable trials for review, and these studies did not all measure the same outcomes.
What Else Should I Know About Erector Spinae Plane Block?
The ESP block is a newer type of pain management used by doctors to relieve pain in the chest, stomach, and even some lower leg areas. It’s quite versatile and can be used by specialized doctors called anesthesiologists to control pain from a wide range of conditions, from persistent shoulder pain to pain after hip surgery.
However, a lot of what we know about ESP block’s effectiveness comes from individual case studies and stories, so more organized scientific studies are being done right now. These studies aim to figure out if ESP blocks can lead to a significant decrease in the use of strong painkillers, lower reported pain levels, and potentially even a shorter hospital stay.
