Comparison Of Postoperative Analgesia In Landmark Guided Erector Spinae Plane Block And Subcostal Transversus Abdominis Plane Block In Laparoscopic Cholecystectomy; A Randomized Controlled Trial
Phase: PHASE3
Conditions: Postoperative Analgesia
Sponsor: Patel Hospital, Pakistan

24-Feb-26 
COVER LETTER 
To: 
Protocol Registration and Results System (PRS) Team 
ClinicalTrials.gov 
U.S. National Library of Medicine 
Subject: Clinical Trial Registration Submission 
Dear Sir/Madam, 
I am submitting our study titled “Comparison Of Postoperative Analgesia In 
Landmark Guided Erector Spinae Plane Block V/S Subcostal Transversus 
Abdominis Plane Block In Laparoscopic Cholecystectomy: A Randomized 
Controlled Trial” for registration on ClinicalTrials.gov. 
This is a prospective, randomized controlled trial to be conducted at Patel Hospital, 
Karachi, Pakistan. The objective of this study is to compare the postoperative 
analgesic efficacy of landmark-guided erector spinae plane block versus subcostal 
transversus abdominis plane block in adult patients undergoing elective 
laparoscopic cholecystectomy. 
The study protocol adheres to Good Clinical Practice (GCP) guidelines. Ethical 
approval will be obtained from the Ethical Review Committee of Patel Hospital 
and CPSP prior to participant enrollment. Written informed consent will be 
obtained from all study participants. 
We kindly request registration of this clinical trial and assignment of a 
ClinicalTrials.gov Identifier. Please let us know if any additional information or 
documentation is required. 
Sincerely, 
Dr. Kulsoom Mehmood 
Principal Investigator 
Patel Hospital, Karachi, Pakistan 
 
 

24-Feb-2026 
TITLE 
COMPARISON OF POSTOPERATIVE ANALGESIA IN LANDMARK  
GUIDED ERECTOR SPINAE PLANE BLOCK V/S SUBCOSTAL  
TRANSVERSUS ABDOMINIS PLANE BLOCK IN LAPAROSCOPIC 
CHOLECYSTECTOMY: A RANDOMIZED CONTROLLED TRIAL  
 
Introduction:  
Postoperative pain after laparoscopic cholecystectomy is significant despite its 
minimally invasive nature.(1) Fascial plane blocks have gained popularity in 
laparoscopic surgery for its potential to provide effective postoperative pain relief. 
(2)  
Recent studies have shown promising results regarding the efficacy of the novel 
block Erector Spinae Plane Block in laparoscopic surgeries. First described by 
Forero et al. demonstrated that ESPB significantly reduced postoperative pain 
scores and opioid consumption in patients undergoing laparoscopic procedures 
compared to standard analgesic regimens.(3, 4) Another study by Ciftci et al. 
(2022) reported similar findings, highlighting the potential of ESPB as a valuable 
adjunct to multimodal analgesia in laparoscopic surgery.(5)  
The ESPB is peri paravertebral block, involves deposition of Local anesthetic 
between erector spinae muscle and transverse process. (6)It’s simpler to perform 
and rather safer as it aims on bony surface and away from pleura and said to target 
both dorsal and ventral rami thus good for both somatic and visceral pain relief.(6-
8) This together with spread at multiple levels makes it excellent choice for a wide 
range of surgical interventions like thoracic, breast, spinal and abdominal 
surgeries.(9, 10)  
A study by Tulgar et al, comparing ultrasound guided ESPB with control 
demonstrated mean fentanyl use to be 6.66ug+-12.44 in ESPB vs 32.33+-22.69 in 
control group which is statistically significant.(6) Another study showed mean pain 
scores were 4.2+-1 in TAP group as compared to 1.7+-1.5 in ESPB group 
(p<0.0001)(8).  

The landmark-guided ESPB can be a valuable technique in low resource countries 
lacking ultrasound access. The landmark guided block can be performed using 
easily accessible instruments. (11) While ultrasound-guided procedures have 
become the gold standard for regional anesthesia, the landmark-guided approach 
offers an alternative when ultrasound equipment is unavailable or costly.(12)  
RATIONALE: 
➢ To the best of our knowledge, there is paucity of data since landmark guided 
Erector spinae plane block has not been evaluated to see the effectiveness of 
the block.  
➢ Due to lack of significant data comparing both blocks, we want to compare 
the postoperative analgesic effect of ESPB v/s STAP block by landmark 
technique as landmark guided approach offers an alternative when 
ultrasound equipment is unavailable or costly. 
OBJECTIVE:  
To compare postoperative analgesia in Erector Spinae Plane Block (ESPB) v/s 
Subcostal Transversus Abdominal Plane Block (STAP) in adults undergoing 
Laparoscopic Cholecystectomy at a Tertiary care hospital.  
 
OPERATIONAL DEFINITIONS:  
Postoperative Analgesia:  
• Analgesia is a medication that relieves pain.  
• Postoperative analgesia is a medication used to relieve pain or discomfort of 
a patient on the operating site. A pain due to which patient cam not perform 
small tasks like sitting, walking or sleeping comfortably.  
Erector Spinae Plane Block (ESPB):  
• A newer regional technique used in which local anesthetic is injected 
between the erector spinae muscle and the transverse process.  
• The solution crossing the internal intercostal membrane blocks the dorsal 
and ventral rami of spinal nerves.  
• The local anesthetic blocks both the somatic and sympathetic nerves.  

Subcostal Transversus Abdominis Plane Block (STAP block):  
• It is a regional analgesia technique which involves the injection of a local 
anesthetic solution into a plane between the internal oblique muscle and the 
transversus abdominis muscle.  
• It blocks the sensory nerves of the anterolateral abdominal wall (T6-L1).  
Pain score (visual analogue scale):  
• The visual analogue scale is a straight line from 1 to 10 with one end 
meaning no pain and the other end meaning the worst pain.  
• A patient will tell the score according to his/her pain intensity.  
 
 
HYPOTHESIS:   
Landmark guided Erector Spinae Plane Block can reliably be performed and can 
provide better analgesia than Subcostal Transversus Abdominis Plane Block in 
laparoscopic cholecystectomy.  
MATERIALS AND METHODS:  
Study design: Double blinded, Randomized controlled trial   
Setting: The study will be conducted at the Operating room, Postoperative 
anesthesia care unit (PACU) and wards of the Patel Hospital, Karachi.  
Study duration: After approval from the REU of College of Physicians and 
Surgeons, 3 to 6 months or till the sample size achieved.  
Sample size: 

The sample size was calculated via Open EPI software for ‘Sample size for 
comparing Two Means’ by using finding of Tulgar, et al. who reported PACU 
rescue analgesic requirement 9.4% in ESPB and 31.3% in STAPB group(8). α 
=5% 1-β =90%  P0  =0.094 Pα = 0.313 n = 25 using formula below:  
  
We will take 30 patients in each group, total sample size will be 60.  
• Group A (ESPB group): 30 patients 
• Group B (STAP group): 30 patients 
Sampling technique:  
Non probability consecutive sampling   
SAMPLE SELECTION:  
INCLUSION CRITERIA:  
Following patients will be included:  
✓ Both male and female patients.  
✓ Patients between the age of 18 to 65years.  
✓ Patients scheduled for Laparoscopic Cholecystectomy.  
✓ Patients with American Society of Anestheologists (ASA) Physical status I, 
II and III.   
✓ Give consent.  
  
 
 
EXCLUSION CRITERIA:  
Following patients will be excluded:  
✓ Hypersensitivity to local anesthetics.  

✓ Infection at the block site.  
✓ Coagulation disorder.  
✓ BMI >40kg/m2  
✓ Patients having pregnancy.  
✓ Conversion to open surgery.  
✓ Drain placement.  
✓ Any neurological or psychiatric disease making them unable to cooperate.   
✓ Patients unwilling to co-operate.  
 
DATA COLLECTION PROCEDURE:  
This study will be performed after the permission of Research evaluation unit 
(REU) of College of Physicians and Surgeons Pakistan (CPSP) and allotment of 
Trail registration number, written informed consent for the study will be obtained 
from the patient who fulfill the inclusion criteria. 
Patients admitted at Patel Hospital Karachi and who fulfills the inclusion 
criteria will be included in the study. Detailed demographic details of each patient 
including name, gender and age will be obtained. Weight and height of each patient 
will be measured by using digital weighing machine and stadiometer, respectively. 
BMI of each patient will be calculated by using BMI formula (BMI=weigh/height2). 
Medical history of each patient will also be inquired. Upon enrolling a patient in 
study a case number will be allotted to each patient. Simple Randomization will be 
done by the closed envelope method to determine which group the patient will be 
included in. The case number will be used to collect data in the postoperative period. 

Patient and the pain assessor both will be blinded to the block given. Anesthesia 
provider doing the perioperative care in the theatre will be handed over the sealed 
envelope enclosing the name of the group, A or B. This anesthesiologist will also 
perform the block but will not take part in collecting data postoperatively nor in the 
data analysis.  
On arrival to the OT, both groups will be monitored with pulse oximetry, 
NIBP, ECG and continuous waveform Capnography prior to induction of anesthesia. 
All patients will be induced with Propofol 2-3mg/kg, Nalbuphine 0.1-0.2mg/kg and 
relaxed with Atracurium 0.5mg/kg. All patients will receive paracetamol 1g IV at 
induction. Anesthesia will be maintained with isoflurane in air oxygen mixture.   
After induction, Group A patients will be positioned in left lateral decubitus 
position. Spinous processes will be identified. At T9 level 2 cm from the midline 
transverse process will be identified at 4cm depth and 30ml of 0.25 % ropivacaine 
will be given on right side just after hitting the transverse process.   
Group B will receive landmark guided Transversus Abdominis plane block 
with 30ml of 0.25% ropivacaine on right side in the supine position.  
 All patients will receive 4mg of ondansetron and 4mg of dexamethasone 
intraoperatively. Upon completion of the surgery, all patients will be reversed with 
Neostigmine and glycopyrrolate and will be shifted to the recovery. 

Standard Analgesia Plan:  All patients will receive Paracetamol 1gram IV every 
6 hours for 24 hours postoperatively.  
  
Postoperative pain assessment and management:  
After 30 minutes in the PACU, postoperative analgesia will be scored by VAS 
scoring. VAS is 11 points scale ranging from 0 to 10 with 0 representing absence 
of pain and 10 as worst imaginable pain. 1-3 will be categorized as mild pain, 4-7 
as moderate and 7-10 as severe pain.   
All patients reporting VAS score of >3 upon arrival in the PACU will receive 
50mg of Tramadol IV by the recovery nurse as rescue analgesic. If pain score 
stayed >3 after 20 minutes, another rescue analgesic 30mg of ketorolac will be 
given IV.   
Outcome measures:  
Primary outcome will be VAS score upon 30 minutes to PACU, and postoperative 
6, 12 and 24 hours. Secondary outcomes will be need for rescue analgesia and time 
for first analgesic request.   
 
Confounder and Biases: 
To address confounding factors and to reduce biases in the study, we used 
randomization in assigning subjects in both groups, we restricted our subjects to 
specific surgical population that is coming for laparoscopic cholecystectomy, and 
we did double blinding that's both participant and investigator and the person who 
did data analysis were blinded to the group. 
 
Statistical analysis:   
The data will be entered and analyzed by the SPSS version 21. Descriptive 
statistics will be summarized by mean +- SD, median with interquartile range 
will be reported for quantitative variables. Frequencies and percentages will be 

reported for categorical variables. To check the normality factor on quantitative 
variables such as age and NRS score will be seed by Shapiro Kolmogorov test.  
To check the significant association between field blocks with ASA status, pain 
scores will be seen by t test or Mann Whitney U test. P value less than 0.05 will be 
taken as significant.  
 
 
 
 
 
 

References: 
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2. Ramkiran S, Jacob M, Honwad M, Vivekanand D, Krishnakumar M, 
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