Study Objective: This research aims to obtain objective data to demonstrate the
effectiveness of two regional block techniques in acute pain management. The primary
objective is to compare the effects of Intertransverse Process Block (ITPB) and M-TAPA
Block on Visual Analog Scale (VAS) scores in patients undergoing laparoscopic
cholecystectomy. Secondary outcomes include evaluating the impact of these blocks on
total opioid consumption within the first 24 hours, requirement for rescue analgesia,
block-related and systemic complications (hematoma, pneumothorax, local anesthetic
systemic toxicity, vascular puncture, infection), patient satisfaction assessed using a
Likert scale, quality of recovery assessed using the QoR-15 questionnaire, and incidence
of postoperative nausea and vomiting.

Materials and Methods: This prospective, randomized clinical study will include voluntary
patients aged 18-65 years, classified as American Society of Anesthesiologists (ASA)
physical status I-III, with a body mass index (BMI) 18-35 kg/m². All participants will be
informed about the study protocol in detail, and written informed consent will be
obtained prior to inclusion. Patients will receive instruction on the use of the VAS for
pain assessment, where 0 denotes no pain and 10 denotes the worst imaginable pain.

Patients who meet the exclusion criteria will be withdrawn from the study. Participants
will be randomly assigned to one of two groups using a computer-generated simple
randomization method (https://www.randomizer.org). Randomization will be performed by a
team member uninvolved in patient care, who will also prepare sealed opaque envelopes to
conceal group allocation until shortly before block administration.

Study Groups and Block Procedures: Group ITP will receive a bilateral ITP block, and
Group M-TAPA will receive a bilateral M-TAPA block. All patients will be monitored with
electrocardiography, peripheral oxygen saturation (SpO#), and non-invasive blood pressure
prior to the block. Premedication with intravenous midazolam (0.02 mg/kg) will be
administered.

ITP Block :

Intertransverse Process Block (ITP) will be performed 30 minutes prior to surgery with
the patient in a sitting position. After skin disinfection with chlorhexidine, the skin
and subcutaneous tissues will be anesthetized using 2-4 mL of 1% lidocaine (Aritmal®,
Osel Pharmaceuticals, Turkey). A linear ultrasound probe (Mindray Diagnostic Ultrasound
System, Model DC-T6) will be positioned along the medial border of spinous processes
level of the T7/T8 thoracic vertebrae.

Anatomical landmarks, including the erector spinae muscle, transverse processes, and
superior costotransverse ligament complex at the T7/T8 level, will be identified. Using
an in-plane approach, a 21 G 0.8x100 mm echogenic insulated needle (Echoplex®+ , Vygon
SA, Écouen, France) will be inserted through the erector spinae muscle toward the
intertransverse tissue complex located between the superior costotransverse ligament and
the transverse processes. Proper needle placement will be confirmed with the injection of
1-2 mL isotonic saline demonstrating separation within the intertransverse plane. Upon
confirmation and negative aspiration, 20 mL of 0.25% bupivacaine hydrochloride (Buvasin®,
Vem Pharmaceuticals, Turkey) will be administered on each side under ultrasound guidance.

M-TAPA Block:

The Block will be performed 30 minutes prior to surgery with the patient in a supine
position. After skin disinfection with chlorhexidine, the skin and subcutaneous tissues
will be anesthetized using 2-4 mL of 1% lidocaine (Aritmal®, Osel Pharmaceuticals,
Turkey). A linear ultrasound probe (Mindray Diagnostic Ultrasound System, Model DC-T6)
will be positioned obliquely along the costal margin at the level of the 10th costal
cartilage.

Anatomical landmarks, including the costal cartilage, rectus abdominis muscle,
transversus abdominis muscle, and internal oblique muscle will be identified. Using an
in-plane approach, a 21G 0.8×100 mm echogenic insulated needle (Echoplex®+ , Vygon SA,
Écouen, France) will be inserted toward the perichondrial plane beneath the 10th costal
cartilage under ultrasound guidance. Proper needle placement will be confirmed with the
injection of 1-2 mL isotonic saline. Upon confirmation and negative aspiration, 20 mL of
0.25% bupivacaine hydrochloride (Buvasin®, Vem Pharmaceuticals, Turkey) will be
administered on each side under ultrasound guidance.

General Anesthesia Upon entry into the operating room, patients will be monitored with
electrocardiography, peripheral oxygen saturation (SpO#), and non-invasive blood
pressure. Anesthesia will be induced with intravenous propofol (2 mg/kg, Polifarma
Pharmaceutical Industry and Trade Inc., Ergene, Turkey), fentanyl citrate (1.5 mcg/kg,
Polifarma Pharmaceutical Industry and Trade Inc., Ergene, Turkey), and rocuronium bromide
(0.6 mg/kg, Muscuron®, Koçak Farma Pharmaceutical and Chemical Industry Co., Turkey).
Anesthesia maintenance will be provided using 6% desflurane in a 40% oxygen-air mixture
and a continuous remifentanil infusion at 0.05 mcg/kg/min. Mechanical ventilation
settings will be adjusted to deliver a tidal volume of 6-8 mL/kg with end-tidal CO#
maintained at 30-35 mmHg. Anesthetic depth will be monitored continuously using a
Bispectral Index (BIS™) monitor (Medtronic plc, Dublin, Ireland), targeting a BIS value
of 40-60. If heart rate or mean arterial pressure increases >20% from baseline, the
remifentanil dose will be titrated accordingly.

Thirty minutes before the end of surgery, all patients will receive 15 mg/kg of
intravenous paracetamol (e.g., Paracerol®, Polifarma Pharmaceutical Industry and Trade
Inc., Ergene, Turkey) and 1 mg/kg of intravenous tramadol. To prevent nausea and
vomiting, 4 mg intravenous ondansetron will be administered. Patients with adequate
spontaneous ventilation will be extubated and transferred to the post-anesthesia care
unit (PACU). Hemodynamic Monitoring Heart rate, systolic blood pressure, diastolic blood
pressure, mean arterial pressure, and oxygen saturation will be recorded at the following
time points: pre-induction (baseline), 5 minutes after induction, 5 minutes after
surgical incision, 15 minutes after incision, and at the end of surgery.

Postoperative Pain and Analgesic Use: Pain will be assessed using the VAS at rest
(static) and during movement (dynamic) at 0, 1, 4, 8, 12, and 24 hours postoperatively.

All patients will use patient-controlled analgesia (PCA) without a basal infusion. The
PCA device will be set to deliver 1 mg of morphine (0.2 mg/mL concentration) with a
10-minute lockout interval. Patients will be instructed to press the PCA button when VAS
≥4. Intravenous paracetamol will be administered every 8 hours.

Rescue analgesia with intravenous tramadol (1 mg/kg) will be provided if VAS scores
remain ≥4. The total amounts of opioids, NSAIDs, and other analgesics will be recorded.

Postoperative Recovery Quality Postoperative recovery will be assessed using the 15-item
Quality of Recovery-15 (QoR-15) questionnaire, which evaluates five domains: pain,
physical comfort, physical independence, psychological support, and emotional state.

Patient Satisfaction Satisfaction will be evaluated using a 5-point Likert scale, where 1
= not satisfied and 5 = very satisfied, based on verbal feedback from both the patient
and the surgeon.

Nausea and Vomiting: Nausea and vomiting will be scored using a 4-point scale:

0 = none

1. = mild

2. = moderate

3. = severe

Potential Complications Any complications associated with the block or the surgical
procedure (e.g., hematoma, pneumothorax, local anesthetic systemic toxicity, vascular
puncture, or infection) will be recorded.