TAP Block vs External Oblique Plane Block for Laparoscopic Cholecystectomy Surgery

Ultrasound (US) guidedTransversus Abdominis Plane Block (TAPB) is performed by injecting a local anesthetic into the plane between the internal oblique and transverse abdominis muscles and provides analgesia in the anterolateral walls of the abdomen after abdominal surgery. Ultrasound-guided TAPB has been commonly used for many years.

US-guided External oblique intercostal block (EOIB) is a novel block performed by injection of local anesthetic between the external and internal oblique muscles at the level of 6th-8th ribs. This block provides abdominal analgesia between T6 and T10 levels. There are studies in the literature showing that it provides effective analgesia. However, there is no study comparing TAPB and EOIB yet.

In this study, we aim to compare the effectiveness of US-guided TAPB and EOIB for postoperative analgesia management after laparoscopic cholecystectomy surgery. Our primary aim is to compare patient recovery scores (QoR15 Turkish version), our secondary aim is to compare postoperative pain scores (24-hour NRS), postoperative rescue analgesic use (opioid/meperidine), and opioid-related side effects (allergic reaction, nausea, vomiting).

Cholecystectomy is the most common abdominal surgery performed in developed countries and is usually performed laparoscopically. The etiology of pain after laparoscopic cholecystectomy is multifactorial and is generally considered visceral pain. Diaphragmatic nerve irritation due to CO2 insufflation into the peritoneal cavity, abdominal distension, tissue damage, damage due to dissection of the gallbladder, sociocultural situation, and individual factors play a role in the occurrence of this pain..

Postoperative pain is an acute pain that is accompanied by inflammation caused by surgical stress and decreases over time with tissue healing. Pain in the postoperative period in patients undergoing laparoscopic cholecystectomy surgery is a serious problem that reduces patient comfort and delays the patient's return to work after surgery (4). Successful postoperative analgesia management prevents many of the complications such as respiratory problems and delayed mobilization (5).

Transverse Abdominis Plane Block (TAPB), performed under ultrasound (US) guidance, is a block that is performed by injecting a local anesthetic into the plane between the internal oblique and transverse abdominis muscles and provides analgesia in the anterolateral walls of the abdomen after surgery. Ultrasound-guided TAPB is commonly used.

TAPB provides analgesia in the abdominal region in T6-L1 dermatomes. Sonoanatomy is easy to visualize on US and the spread of local anesthetic can be seen. Analgesia occurs in several dermatomes with the cephalo-caudal spread of the local anesthetic solution. Studies are proving that TAP block is effective in some abdominal surgeries such as hysterectomy, cesarean section, cholecystectomy, inguinal hernia and prostatectomy. Sensory block areas formed by TAPB are highly variable and may result in insufficient blocks.

External oblique block (EOIB) performed under US guidance is a block performed by injection of local anesthetic between the external and internal oblique muscles. This block provides abdominal analgesia covering the T6-T10 dermatomes. There are studies in the literature proving that it provides effective analgesia (12-14). However, no study comparing TAPB and EOIP has been published yet.

In this study, we aim to compare the effectiveness of US-guided TAPB and EOIB for postoperative analgesia management after laparoscopic cholecystectomy surgery. Our primary aim is to compare patient recovery scores (QoR15 Turkish version), our secondary aim is to compare postoperative pain scores (24-hour NRS), postoperative rescue analgesic use (opioid/meperidine), and opioid-related side effects (allergic reaction, nausea, vomiting).

Eligibility Criteria:
Inclusion Criteria:

* American Society of Anesthesiologists (ASA) classification I-II
* Scheduled for laparoscopic cholecystectomy surgery under general anesthesia

Exclusion Criteria:

* Bleeding diathesis
* anticoagulant treatment
* local anesthetics and opioid allergy
* Infection at the site of the block
* Patients who do not accept the procedure