Analgesic Effect of Bilateral Subcostal Quadratus Lumborum Block in Laparoscopic Colorectal Surgery

Effective postoperative pain management is crucial for promoting early recovery and ambulation following laparoscopic colorectal surgery. Regional anesthesia techniques, like interfascial plane blocks, are increasingly being used to achieve this. The quadratus lumborum block (QLB) is a relatively new approach in abdominal surgeries, providing significant pain relief by blocking both somatic and sympathetic nerves. In particular, the anterior QLB technique allows local anesthetic to spread to the thoracic paravertebral space, making it potentially more effective for postoperative analgesia. The hypothesis of this study is that bilateral subcostal anterior QLB can reduce both postoperative pain and opioid consumption in laparoscopic colorectal surgery.

Postoperative pain management is a critical factor in enhancing recovery and ambulation following laparoscopic colorectal surgery. Effective analgesia is necessary to reduce complications, improve patient comfort, and shorten hospital stays. In this context, multimodal analgesia is a commonly used strategy that combines various analgesic drugs, such as paracetamol, nonsteroidal anti-inflammatory drugs (NSAIDs), and opioids, to manage pain more effectively by targeting different pathways.

Although opioids are considered the gold standard for postoperative pain control, their use is associated with several undesirable side effects, including nausea, vomiting, dizziness, constipation, and respiratory depression. These opioid-related complications can delay recovery, increase patient discomfort, and extend hospital stays. Therefore, minimizing opioid consumption while still providing effective pain relief is a primary goal in postoperative pain management, particularly for surgeries such as laparoscopic colorectal procedures.

To achieve this goal, regional anesthesia techniques have gained increasing popularity. These techniques, such as interfascial plane blocks, have the potential to reduce opioid use and improve pain control by targeting specific nerve pathways. One of the more recent approaches is the quadratus lumborum block (QLB), which involves the injection of local anesthetics near the quadratus lumborum muscle. This block is particularly useful in abdominal surgeries because it can provide pain relief by affecting both somatic and sympathetic nerves, leading to broader and more effective pain coverage.

The QLB has four different approaches: anterior, lateral, posterior, and intramuscular. The anterior QLB is of particular interest in this setting because it involves the injection of local anesthetic between the quadratus lumborum and psoas muscles, potentially allowing the anesthetic to spread into the thoracic paravertebral space. This spread could result in the blockade of both the somatic nerves and the thoracic sympathetic chain, offering more comprehensive pain relief that is beneficial for abdominal surgeries like colorectal procedures.

The potential advantages of the anterior QLB in laparoscopic colorectal surgery include reduced postoperative pain, decreased opioid consumption, and fewer opioid-related side effects. Additionally, regional anesthesia techniques like QLB may reduce postoperative complications, including respiratory issues, which are particularly important in abdominal surgeries that involve the diaphragm and lower thoracic nerves.

In this study, the hypothesis is that bilateral subcostal anterior QLB, administered during laparoscopic colorectal surgery, will significantly reduce both postoperative pain and the need for opioids.

The aim of this study is to investigate the effects of Bilateral subcostal anterior QLB on postoperative acute pain scores (0-24 hours) and 24- hour opioid consumption in patients who underwent laparoscopic colorectal surgery. Our study, which the investigators think will contribute to the literature, was planned as a prospective, randomized, controlled, parallel-group study.

Patients will be divided into two groups:

Group S-QLB:

A bilateral S-QLB (40 ml 0.25% bupivacaine + 1:400.000 adrenaline) will be performed. In addition, IV morphine-PCA will be applied postoperatively for 24 hours.

Group Control :

IV morphine-PCA will be applied postoperatively for 24 hours.

Eligibility Criteria:
Inclusion Criteria:

* 18- 75 years old,
* patients classified as ASA I-III who have signed an informed consent form
* scheduled for elective laparoscopic colon surgery (partial or total)

Exclusion Criteria:

* BMI \>30 kg/m²
* Pregnancy
* Contraindication to regional anesthesia
* Presence of severe cardiac, hepatic, or cerebrovascular disease
* History of allergy to local anesthetics or systemic opioids
* History of chronic pain
* Patients with alcohol or drug dependence
* Patients unable to assess pain scores