Efficacy of ultrasound guided erector spinae block in comparison to quadratous lumborum block for post operative analgesia in patients undergoing percutaneous nephrolithotomy surgery:A randomized control trial

INTRODUCTION Pain management following percutaneous nephrolithotomy (PCNL) remains a critical aspect of postoperative care, as inadequate analgesia can lead to increased morbidity,

delayed recovery, and prolonged hospital stay. To address these concerns, regional anesthesia techniques, particularly ultrasound-guided blocks, have gained popularity due to their efficacy in providing targeted analgesia while minimizing systemic complications. Among the emerging regional anesthesia

techniques, the Erector Spinae Plane (ESP) Block and the Anterior Quadratus Lumborum (AQL) Block have been increasingly utilized for managing postoperative

pain following abdominal and urological surgeries. Both blocks have shown promising results in various surgical settings; however, comparative data on their

efficacy in PCNL surgery remain limited. While both blocks have shown efficacy individually in various surgical settings, there

remains limited evidence directly comparing their analgesic effectiveness in patients undergoing PCNL. This randomized prospective study aims to evaluate and compare the

efficacy, safety, and opioid-sparing effects of ultrasound-guided ESP block versus anterior QL block for postoperative pain management in PCNL.

NEED AND JUSTIFICATION OF THE STUDY Percutaneous nephrolithotomy (PCNL) is associated with significant postoperative pain

due to the nature of renal access and tract dilation. Effective pain management is crucial to enhance patient recovery, reduce opioid consumption, and minimize complications.

Regional anesthesia techniques like the Erector Spinae Plane (ESP) block and the Anterior Quadratus Lumborum block have emerged as promising options for

postoperative analgesia.Ultrasound-guided ESP and QL blocks both target different fascial planes and neural pathways, with potential variations in analgesic efficacy, duration, and side effect

profiles. However, limited comparative data exists on their relative effectiveness specifically in PCNL procedures. This randomized prospective study aims to evaluate

and compare the efficacy of these two blocks, contributing to optimized pain management strategies in urological surgeries.

NEED OF THE STUDY  As Conventional analgesic approaches like systemic opioids have limitations such as

nausea, sedation, hypotension and delayed mobilization.This study uses Ultrasound-guided Erector Spinae block (ESP) and Anterior Quadratus Lumborum(AQL) blocks which are emerging regional anesthesia techniques offering

effective, opioid-sparing analgesia with a favourable safety profile.

PRIMARY OBJECTIVE To compare the duration of post operative analgesia provided by ESP Block and AQL Block.

SECONDARY OBJECTIVETo assess total tramadol consumption in the postoperative period in first 24 hrs.

, To evaluate hemodynamic stability and incidence of block-related complications in both groups, To assess overall patient satisfaction using 5 point Likert scale.

METHODOLOGY RESEARCH DESIGN A Randomized Prospective Study

TARGET POPULATION This randomized prospective study will be conducted on patients aged between 18 and 65 years belonging to ASA classes I & III scheduled for

elective unilateral percutaneous nephrolithotomy surgery.

SAMPLE SIZE CALCULATION To compensate for the 10% dropouts we have taken total sample size of 60 (30 in each group)

PROCEDURE Preoperative assessment will be conducted on the day before surgery, during which a

thorough history and clinical examination will be done and recorded. In the operating

room, non-invasive blood pressure, oxygen saturation and electrocardiography will be

monitored, and the baseline vitals will be noted. Peripheral venous access will be

established with a 20 gauge IV cannula.

ESP group- After all aseptic precautions, 2 ml of 2% lidocaine infiltration will be given

subcutaneously at the site where the block will be given. Under ultrasound guidance, a

90 mm 22 gauge spinal needle will be inserted in a cranial to caudal direction by the in-

plane needling technique, aiming at the tip of the transverse process. 20 ml of

Ropivacaine 0.2% will be injected after making mild contact with the transverse process

tip.

QL group- The patient will be placed in the lateral decubitus position according to the

selected site of surgical intervention. The low-frequency convex probe of ultrasound will

be positioned horizontally in the anterior axillary line halfway between the subcostal

margin and iliac crest to locate the triple abdominal muscle layers, then the probe will be

relocated subsequently to the posterior axillary line until the quadratus lumborum

muscle can be visualized with its attachment to the lateral edge of the transverse process

of the L4 vertebral body, With the psoas major muscle places anteriorly, the erector

spinae muscle posteriorly and the quadratus lumborum muscle adherent to the apex of

the transverse process, this is a well-recognizable pattern of a shamrock with three

leaves. A 22-gauge, 90 mm spinal needle will be inserted in plane relative to the

ultrasound probe passing in posterior to anterior direction through the QL muscle to

reach the border between the QL and psoas major muscle. After confirmation of

negative blood aspiration, 20 ml of Ropivacaine will be injected.

After giving the block, with proper aseptic measures; spinal anaesthesia (with injection

bupivacaine 0.5% 3.0 ml) with a fixed adjuvant (injection fentanyl 10 microg) for all the

patients will be administered in the sitting position.