Overview of Quadratus Lumborum Block
Doctors use a variety of methods to numb or relieve pain in the chest, stomach, and pelvic areas. Each method is used in different situations, but there are certain cases where they cannot be used due to medical reasons. For nearly 50 years, doctors have often used nerve and tissue blocking techniques to relieve pain after surgery as an alternative to anesthetics that can affect the entire body.
These techniques were first used in specific areas of the body such as the lower abdominal region, the area between the ribs and the hip, and in the muscles lining the abdominal cavity. In the early 21st century, doctors began using a technique called the transversus abdominis plane (TAP) block, which focuses on a specific area of the abdominal wall.
This article discusses a recent variation of the TAP block developed by Rafael Blanco called the quadratus lumborum block (QLB). The QLB is a new approach to numbing a specific area in the lower back and abdominal region for pain relief.
Anatomy and Physiology of Quadratus Lumborum Block
The Quadratus Lumborum Block (QLB) is a method of blocking pain in the back of your abdomen. It’s different from the Transversus Abdominis Plane block (TAP). To perform this method, a local anesthetic (a medication that numbs a specific area of the body) is injected into a part of your body called the thoracolumbar fascia (TLF). The TLF is an area that extends backward from the muscle layers of your abdominal wall, covering three major muscles in your back: the quadratus lumborum, psoas major and the erector spinae.
The TLF is essentially a connection from your lower spine to your mid-back and it’s made up of three layers named for the muscles they’re related to. It contains different types of nerve endings that can sense pressure, pain, and control blood flow. The local anesthetic that’s injected into this area can block these nerve endings, which is why it can provide relief from ‘visceral’ pain, or discomfort that’s coming from your organs.
There are different ways that this pain-blocking method can be performed, each based on where the anesthetic is injected in relation to the quadratus lumborum muscle. Variants of this method include QL1, QL2, QL3 and QL4 blocks.
In QL1, the anesthetic is injected on the side of the muscle. QL2 involves an injection behind this muscle, in an area known as the ‘lumbar interfascial triangle’. QL3, also known as transmuscular block, is when the injection is in front of the muscle at the level of the L4 vertebral body (a section of your spine) – to perform this, the doctor uses an ultrasound to identify a specific image, known as the ‘shamrock sign’. Lastly, QL4 involves an injection directly into the quadratus lumborum muscle itself.
Why do People Need Quadratus Lumborum Block
The Quadratus Lumborum Block (QLB) is a type of pain relief treatment that works by distributing a local anesthetic over a large area. This numbs the region and helps control pain. The areas that are usually affected are between the T7 and the L1, which are terms used to describe locations on your spine. This makes QLBs particularly useful for surgeries involving the abdomen and pelvic areas.
As a result, the QLB technique is often used to help manage and reduce pain after surgeries related to the abdomen, pregnancy and childbirth, female reproductive health, and urinary health. In fact, there have been reports that illustrate the successful use of QLBs in surgeries of the hip, upper leg bone (femur), and the lower part of the spine (lumbar vertebrae).
When a Person Should Avoid Quadratus Lumborum Block
There are certain circumstances where a Quadratus Lumborum Block (QLB) – a type of pain management procedure – cannot be carried out, just like with other similar procedures such as the Transversus Abdominis Plane block or the Fascia Iliaca block. These circumstances include:
- If the patient does not want the procedure.
- If the patient is allergic to the local anesthetic – the medicine that numbs a specific area of the body.
- If the patient is at risk of local anesthetic toxicity – meaning they’ve already received the highest dose of local anesthetic that is deemed safe.
- If the patient has an infection at the site where the procedure needs to be performed.
There’s ongoing debate among medical experts about whether it’s safe to perform a QLB, or other similar procedures, on a patient who has a coagulopathy (a condition that affects the blood’s ability to clot) or is taking anticoagulants (blood-thinning medicines). Some doctors think it may be safe to perform these procedures on such patients. However, recent guidelines from the American Society of Regional Anesthesia and Pain Medicine caution against carrying out deep regional anesthetic procedures on patients taking anticoagulants. This is because of multiple reports of significant health complications (morbidity) resulting from such situations.
Equipment used for Quadratus Lumborum Block
The process of treating your condition will require the use of specific medical equipment, like:
– Skin antiseptic: This is used to clean your skin to prevent infections.
– Sterile towels and gauze: Clean towels and gauze are used to cover and clean wounds.
– A 22-gauge needle that is 100 to 150 cm long: This needle is for injecting a local anesthetic, which will numb the area where the doctor is about to work.
– Local anesthetic: This medication will make you feel no pain in the area of your body where the doctor is working.
– Sterile gloves: These are worn by medical professionals to keep the area clean.
– Ultrasound machine: This device allows the doctor see inside your body without having to make a cut or incision.
– Various types of ultrasound probes: Depending on where the doctor needs to look, they may use either a high frequency (6 to 15 MHz) linear ultrasound probe transducer, or a lower frequency (2 to 6 MHz) curvilinear transducer.
– ECG monitor: This measures the electrical activity of your heart.
– Blood pressure monitor: This equipment keeps track of how hard your heart is pumping.
– Pulse oximetry: This device measures how well your body is absorbing oxygen.
In most cases, the doctor will choose a long-lasting local anesthetic, like 0.2% ropivacaine or 0.25% bupivacaine, to keep control over the pain. The doctor will carefully calculate the maximum amount of anesthetic that can be safely used, especially if you’re going to receive the numbing medication on both sides of your body.
Who is needed to perform Quadratus Lumborum Block?
The only person needed to perform anesthesia using ultrasound as a guide is a trained medical professional. However, an additional professional, like a nurse, can help out. They can keep an eye on the patient and give any necessary medications. In other words, there’s one main person making sure you’re numbed properly and safely, with someone else available to help watch over you, keep you comfortable, and give you any required drugs in the process.
Preparing for Quadratus Lumborum Block
Before any medical procedure, it’s important that the doctor talks to the patient and explains what will happen, the possible benefits and downsides, and other options they may have. This is called ‘informed consent’ – it means the patient understands and agrees to the treatment. In this case, the doctor needs to discuss how the patient will be positioned during the procedure. This might be lying on their back for a lateral or posterior QLB, lying on their side for an intramuscular QLB, or an anterior QLB. QLB here stands for Quadratus Lumborum Block, which is a technique to manage pain.
Once the patient understands and consents to the procedure, the doctor will use an ultrasound to make sure they’re targeting the right area. After that, they’ll clean the skin area with a special solution (like chlorhexidine or povidone-iodine) to prevent infection. These solutions are antimicrobial, which means they kill microorganisms or stop them from growing, thus reducing the risk of infection.
How is Quadratus Lumborum Block performed
The Quadratus Lumborum Block (QLB) is a type of local anesthesia procedure that can be performed in four different ways: lateral, anterior, posterior, and intramuscular. Here’s a simple explanation of these variations:
1. Lateral QLB: This procedure is done with you lying on your back or your side. The doctor places an ultrasound probe, a tool that uses sound waves to create images, on your side, in the area between the bottom of your ribcage and the top of your hip, near the armpit area (this is known as the ‘triangle of Petit’). The doctor then uses the ultrasound images to recognize different layers of abdominal muscles. The needle is then carefully inserted and advanced through the front muscles of the abdomen until it reaches a muscle called Quadratus Lumborum (QL). The correct placement of the needle allows the anesthetic to spread between the QL and a layer of tough tissue in the middle of the back, numbing the area.
2. Anterior QLB: In this procedure, you’ll be positioned lying on your side. The ultrasound probe is placed above your hip at the middle side of your body. The doctor then uses the probe to identify a certain sign called the ‘shamrock’ sign. The needle is then inserted and moved through the QL muscle to a middle layer of the tough tissue between the QL and another muscle in the back called Psoas Major (PM). When the needle is correctly positioned, the anesthetic is spread in between these two muscles.
3. Posterior QLB: For this procedure, you’ll be lying on your back just like the lateral QLB. The doctor uses the ultrasound image to locate the back border of the QL muscle and positions the needle at that point, allowing the anesthetic to spread through the middle layer of tough tissue and into an area called the interfascial triangle.
4. Intramuscular QLB: For this method, you can be positioned either lying on your side or your back. After identifying the QL muscle with the ultrasound, the doctor inserts the needle in a specific direction and injects the anesthetic directly into the muscle.
These procedures are used to numb specific areas of the body before surgery or other medical treatment. The strategy used will depend on your particular circumstances and the surgeon’s preference.
Possible Complications of Quadratus Lumborum Block
When doctors perform a type of anesthesia called a Quadratus Lumborum Block (QLB), they need to make sure that the area is clean to avoid any infections. The good news is that QLBs have a lower chance of causing infections compared to other more invasive methods of anesthesia. Moreover, until now, there have been no reported instances of people getting infections from QLB. Also, doctors need to know any history of blood clotting issues or use of blood thinners in patients before the procedure to prevent excessive bleeding or formation of hematoma – a swelling of clotted blood within the tissues.
Any method of regional anesthesia, which numbs a larger area of your body and you would be awake though relaxed, involves using drugs that can potentially be toxic if they absorb into your body. This is known as Local Anesthetic Systemic Toxicity (LAST). However, the QLB method is associated with lower levels of a drug named ropivacaine in the blood than another type of anesthesia called TAP blocks. This makes QLB potentially safer when we consider the risk of LAST. Furthermore, just like infections, there’ve been no reported cases of LAST from QLB.
What Else Should I Know About Quadratus Lumborum Block?
QLB, short for Quadratus Lumborum Block, is a type of nerve block that offers several benefits compared to other kinds of pain relief techniques. It provides better pain relief and reduces the need for strong painkillers known as opioids. Research also suggests that the QLB may cover more types of abdominal pain better.
Moreover, where the injection is given also adds a safety advantage. The injection sites are quite far from the abdominal cavity, internal organs, and large blood vessels. This distance minimizes the risk of affecting these areas during the procedure.
