The aim of this study is to evaluate the effectiveness of adding fentanyl to the TAP block in laparoscopic cholecystectomy cases. It is hypothesized that the addition of fentanyl to the TAP block will enhance the quality of postoperative analgesia and prolong the duration of blockade compared to the TAP block performed with bupivacaine alone. The study aims to determine the most effective approach by comparing these two treatment methods with a control group.

Cholecystectomy was first performed in 1882 by Karl Langenbuch and is widely used for the treatment of symptomatic gallbladder diseases, such as acute cholecystitis and cholelithiasis. Today, the laparoscopic technique is preferred due to its advantages, including faster recovery, better cosmetic outcomes, and shorter hospital stays. However, despite these benefits, postoperative pain, particularly in the shoulder and abdomen, remains a common issue after laparoscopic surgery and is one of the primary causes of delayed discharge. This pain can be attributed to incision sites, peritoneal irritation caused by the insufflation gas, and trocar entry points.

Effective management of postoperative pain is crucial for accelerating recovery and preventing the development of chronic pain. One of the key strategies in multimodal analgesia is the Transversus Abdominis Plane (TAP) block, which can reduce both postoperative pain and the need for opioids. First described by Rafi in 2001, TAP block gained widespread use after Hebbart et al. demonstrated in 2007 that it could be applied more effectively and safely under ultrasound guidance. The block involves injecting local anesthetics into the neurofascial plane between the transversus abdominis and internal oblique muscles, where the intercostal, subcostal, ilioinguinal, and iliohypogastric nerves run.

Since the identification of opioid receptors in peripheral nerves, there has been interest in combining opioids with local anesthetics to enhance the duration and quality of peripheral nerve blocks. Studies have shown that certain opioids, including fentanyl and sufentanil, exhibit local anesthetic-like effects. Fentanyl, a commonly used opioid, has been shown to improve analgesia quality and prolong the duration of subarachnoid blocks when combined with local anesthetics.

This study aims to evaluate the effectiveness of adding fentanyl to the TAP block, which is routinely performed in our clinic, in laparoscopic cholecystectomy cases. The hypothesis is that the addition of fentanyl to bupivacaine in the TAP block will improve the quality of postoperative analgesia and prolong the block duration.

A total of 66 patients undergoing laparoscopic cholecystectomy will be included in the study. Patients will be randomized into three groups:

Group 1: TAP block with bupivacaine only, Group 2: TAP block with bupivacaine and fentanyl, Group 3: Control group (no TAP block). All patients will receive standard general anesthesia protocols, and TAP block will be performed before the surgical procedure. Postoperatively, pain scores (VAS), rescue analgesia requirements, additional analgesic and antiemetic use, complications, and patient satisfaction will be evaluated. The study will also assess whether fentanyl prolongs the block duration and improves postoperative analgesia quality.

The goal of this study is to compare these approaches and determine the most effective method for managing postoperative pain in laparoscopic cholecystectomy cases.

Inclusion Criteria:

• Patients aged 18 to 70 years
• American Society of Anesthesiologists (ASA) classification I-II-III according to the American Society of Anesthesiologists
• Patients who provide written informed consent
• Patients scheduled for elective laparoscopic cholecystectomy

Exclusion Criteria:

• Pregnancy or suspected pregnancy
• BMI > 35
• Known allergy to local anesthetics or opioids
• Suspected coagulopathy or infection at the injection site
• Severe neurological, psychiatric, cardiovascular, liver, or renal failure
• Patients converted to open surgery intraoperatively

This study is a double-blind randomized trial. Both the researchers assessing postoperative pain and the participants will be blinded.