"The Efficiency of Laparoscopic-assisted Transversus Abdominis Plane Block for Post-laparoscopic Cholecystectomy Pain

This prospective, randomized, controlled, observer and patient-blind study will be conducted by the General Surgery, Anesthesiology and Reanimation Departments of Private Medicabil Hospital in accordance with the Declaration of Helsinki and Good Clinical Practice Guidelines. Hospital ethics committee approval was obtained for the study and the study was conducted between january 2021 and april 2020. Informed consent for the study to be conducted will obtained from each patient.

Study Inclusion and Exclusion Criteria The study will included American Society Anesthesia (ASA) 1 and 2 patients aged 18-70 years who underwent conventional four-quadrant LC.

Exclusion criteria:

1. Patients who did not agree to participate in the study,
2. ASA 3 and above patients, those who will undergone emergency surgery, open cholecystectomy
3. BMI of >40,
4. İntraoperative major complications,
5. History of severe allergy,
6. Chronic analgesic use, Study Parameters
7. gender, age, presence of comorbidity, weight, height, smoking status, operative time, length of hospital stay, intraoperative fluid volume, and developed complications 2. the primary data of the study: the postoperative 1, 3, 6, 12, and 24-hour VAS scores (0 lowest-10 highest) at rest and on cough after surgery 3. the rate of rescue analgesic dose of tramadol 4. as the secondary data: nausea-vomiting, shoulder pain, discharge duration exceeding 24 hours, and pre-discharge patient satisfaction (strongly disagree 1-strongly agree 5 on a Likert-type scale).

The mean postoperative 1-hour Visual Analog Scale (VAS) scores and the rates of rescue analgesic use of 20 patients operated before the study were determined. With these values, it was calculated that there should be 40 patients in each group, with a 33% decrease in pain scores and rescue analgesic use after LTAP at a statistical power of 80% and a significance level of 5%. The study was conducted with 30 patients in each group for a better analysis.

Randomization Randomization will be performed immediately before the surgery using a computer-generated random number table and was reported to the surgeon who would perform the surgery. Anesthesia team, the patient, and the clinical nurses who carry out and record the postoperative evaluation will blinded to the group of patients.

Procedure and Study Groups

The study groups were planned as follows:

Group 1 (Standard IV analgesia group (SA), n=40):

Group 2 (Local analgesia group (LA), n=40):

Group 4 (Four qudrant-Laparoscopic-assisted transversus abdominis plane block (LTAP) group, n=40) Postoperative analgesic administration will be carried out following a standard protocol in all groups. Acetaminophen 1 g was gradually will administered every 6 hours depending on the level of pain, and diclofenac sodium will intravenously administered every 12 hours depending on the requirement. In the case of a pain score above 4, tramadol 100 mg will be given intravenously as a rescue analgesic.

Block technique:

After the induction of anesthesia, the first port was inserted through the umbilicus and a 12 mmHg pneumoperitoneum was established as a standard. Under the direct view of the laparoscopic camera, the block was performed by inserting a 22-G needle just above the iliac crest through the midclavicular line posteriorly into the triangle of Petit and then inserting the needle below the costal arch through the midclavicular line towards the anterior axillary line into the subcostal plane. The block needle was advanced under direct view until the two pops were felt and the extraperitoneal space was reached without puncturing the parietal peritoneum, and pulling back the needle 0.5 cm, the area of the thin transversus abdominis muscle fibers was infiltrated. In this area, the correct plane of the needle tip was confirmed by observing Doyle's bulge and the spread of the local anesthetic.11,14 This procedure was performed as the bilateral four-quadrant block in BLTAP group and right sided two-quadrant block in ULTAP group.

Statistical Analysis The SPSS (IBM SPSS, version20) software will be used for the statistical analysis. The t-test was will use for continuous variables, while the chi-square test for categorical values. The level of significance was set at p<0.05.