Ultrasound-guided quadratus lumborum block (QLB) is a fascial plane block where local anesthetic is injected adjacent to the quadratus lumborum muscle to anesthetize the thoracolumbar nerves.

The ultrasound (US) guided erector spina plane block (ESPB) is a novel interfacial plan block defined by Forero et al. at 2016. Visualization of sonoanatomy with US is easy, and the spread of local anesthesic agents can be easily seen under the erector spinae muscle. Thus, analgesia occurs in several dermatomes with cephalad-caudad way. It has been reported that ESPB provides lumbar analgesia at T10-12, L3.

This study aims to compare US-guided ESPB and posterior QLB for postoperative analgesia management after lumbar disc herniation-laminectomy surgery.

Spine surgery in thoracolumbar region is one of the most common surgeries performed for the treatment of leg and back pain. Pain management is especially important for these patients since chronic pain often occurs after surgery. Severe pain may occur at postoperative period in patients following lumbar disc herniation (LDH) operation. Postoperative effective pain treatment provides early mobilization and shorter hospital stay, thus complications due to hospitalization such as infection and thromboembolism may be reduced.

Opioids are one of the most preferred drugs among the analgesic agents. Parenteral opioids are generally performed for patients after surgery. However opioids have undesirable adverse events such as nausea, vomiting, itching, sedation and respiratory depression (opioid-related adverse events).

Various methods may be performed to reduce the use of systemic opioids and for effective pain treatment. US-guided interfascial plane blocks have been used increasily due to the advantages of ultrasound in anesthesia practice. Ultrasound-guided quadratus lumborum block (QLB) is a fascial plane block where local anesthetic is injected adjacent to the quadratus lumborum muscle to anesthetize the thoracolumbar nerves.

The ultrasound (US) guided erector spina plane block (ESPB) is a novel interfacial plan block defined by Forero et al. at 2016 The ESPB contains a local anesthetic injection into the deep fascia of erector spinae. This area is away from the pleural and neurological structures and thus minimizes the risk of complications due to injury. Visualization of sonoanatomy with US is easy, and the spread of local anesthetic agents can be easily seen under the erector spinae muscle. Thus, analgesia occurs in several dermatomes with cephalad-caudad way. Cadaveric studies have shown that the injection spreads to the ventral and dorsal roots of the spinal nerves. ESPB provides thoracic analgesia at the T5 level, abdominal analgesia at the T7-9 level, and lumbar analgesia at T10-12, L3 level. In the literature, it has been reported that ESPB provides effective analgesia after lumbar spine surgery.

This study aims to compare US-guided posterior QLB block and ESPB for postoperative analgesia management after lumbar disc herniation-laminectomy surgery. The primary aim is to compare postoperative pain scores (NRS) the secondary aim is to evaluate postoperative opioid consumption, motor block, and adverse effects related to opioids (allergic reaction, nausea, vomiting).

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) classification I-II
• Scheduled for lumbar disc herniation-laminectomy surgery under general anesthesia

Exclusion Criteria:

• history of bleeding diathesis,
• receiving anticoagulant treatment,
• known local anesthetics and opioid allergy,
• infection of the skin at the site of the needle puncture,
• pregnancy or lactation,
• patients who do not accept the procedure
• Change in surgical technique in the intraoperative period

Individual participant data (IPD) will not be shared

Outcomes Assessor and participant were blinded to the study