top of page
Search
Valkyrie Blog Team

QLB: Your Secret Weapon Against Surgical Pain

The Quadratus Lumborum Block (QLB) is a fascinating technique used in anesthesia and pain management to provide analgesia for abdominal and hip surgery. This fascial plane block is performed by injecting local anesthetic adjacent to the quadratus lumborum muscle with the goal to anesthetize the thoracolumbar nerves. Ultrasound guidance is commonly used for precise localization. It is commonly used for various surgeries, including exploratory laparotomy, large bowel resection, and Ileostomy. Let's dive into the details! 


Anatomy of the Quadratus Lumborum Muscle

The quadratus lumborum muscle is a posterior abdominal wall muscle. It originates from the posteromedial iliac crest and inserts into the medial border of the twelfth rib and the transverse processes of the first to fourth lumbar vertebrae. Its lateral free border is angled from craniomedial to caudolateral. Posterior to the quadratus lumborum muscle lies the erector spinae muscle group, which includes the multifidus, longissimus, and iliocostalis muscles. 

 

Now that we have reviewed the anatomy and indications, let's walk through a step-by-step guide for performing a Quadratus Lumborum Block (QLB). This technique involves injecting local anesthetic in planes defined by the thoracolumbar fascia around the QL muscle.  


Here are the most common key steps: 

Patient Positioning

  • Place the patient in a lateral decubitus position with the affected side up. 

  • Ensure adequate exposure of the lumbar area. 

Ultrasound Setup

  • Use a high-frequency linear ultrasound probe. 

  • Scan the lumbar region to visualize the QL muscle, psoas muscle, and thoracolumbar fascia. 

Identify Anatomical Landmarks

  • Locate the posteromedial iliac crest, the medial border of the 12th rib, and the transverse processes of L1 to L4. 

  • The QL muscle lies between these points, with the psoas muscle medial and anterior to it. 

Probe Placement

  • Place the ultrasound probe in a transverse orientation just below the 12th rib. 

  • Visualize the QL muscle and its surrounding fascia layers. 

Needle Insertion

  • Insert a needle in-plane from a lateral approach, directing it toward the QL muscle. 

  • Aim to reach the interfascial plane between the QL muscle and the thoracolumbar fascia. 

Local Anesthetic Injection

  • Confirm needle tip position using real-time ultrasound guidance. 

  • Inject local anesthetic (e.g., 20-30 mL of 0.25% bupivacaine) into the interfascial plane. 

  • Ensure even spread along the QL muscle. 

Evaluate Spread

  • Observe the anesthetic spread between the QL muscle and the fascia layers. 

  • Assess coverage of the thoracolumbar nerves. 

Post-Procedure Monitoring

  • Monitor the patient for any complications (e.g., local anesthetic toxicity, vascular injury). 

  • Assess pain relief and adjust management as needed. 


Variations of Quadratus Lumborum Block (QLB) can be adapted based on patient positioning and approach. Here are a few: 

Approaches 

  1. Lateral Approach (QLB1)

    1. Needle insertion occurs lateral to the QL muscle. 

    2. Targets the anterior thoracolumbar fascia. 

    3. Useful for abdominal surgeries. 

    4. May have less extensive spread than the posterior approach. 

  2. Posterior Approach (QLB2)

    1. Needle insertion occurs posterior to the QL muscle. 

    2. Injection targets the middle thoracolumbar fascia. 

    3. Provides effective analgesia with less motor blockade than the anterior approach. 

    4. Widens dye spread compared to the lateral approach [3]. 

  3. Anterior Approach (Transmuscular QL Block or QLB3)

    1. Needle insertion occurs anterior to the QL muscle. 

    2. Injects between the QL muscle and the psoas major muscle. 

    3. Risks retroperitoneal spread of hematoma. 

    4. Effective for pain relief but may cause quadriceps weakness due to lumbar plexus involvement [1] [ ] [3].  

Patient Positioning

  • Lateral Decubitus Position

    • Most common for QLB. 

    • Patient lies on their side, with the affected area facing upward. 

  • Prone Position

    • Used for posterior QLB. 

    • Patient lies face down. 


Whether you’re an anesthesiologist pr a pain management specialist, QLB opens new horizons in pain relief. As we delve into the intricacies of fascial planes, needle trajectories, and patient positioning, remember that precision matters. The quadratus lumborum muscle, once a hidden gem, now takes center stage in our quest for optimal patient care.


So, as you step into the operating room or lecture hall, armed with newfound knowledge, embrace the art and science of QLB. Let’s continue exploring, innovating, and elevating our practice—one block at a time.


 

Did you know that Valkyrie offers options for training and practice for more than 30 blocks?



 

Blog Sources:  

2.        Quadratus Lumborum Block 

Images by NYSORA.com

 

25 views0 comments

Comments


bottom of page