Sensory Analysis and Cutaneous Mapping of Different Regional Anesthesia Techniques

February 25, 2026 updated by: Samsun University

Sensory Analysis and Cutaneous Mapping of Different Regional Anesthesia Techniques in Laparoscopic Cholecystectomy Surgery: A Prospective Observational Study

This prospective observational study aims to evaluate and compare the sensory block distribution and regression patterns of two regional anesthesia techniques - External Oblique Plane Block (EOPB) and Serratus Intercostal Plane Block (SIPB) - in patients undergoing laparoscopic cholecystectomy.

Thirty adult patients (ASA I-III, BMI ≤ 35 kg/m², ≥50 kg) scheduled for elective laparoscopic cholecystectomy procedures will be included, with 20 in each block group. Sensory block areas will be assessed using pinprick test, and dermatomal mapping will visualize the spread. The findings are expected to improve understanding of block behavior and guide multimodal analgesia strategies in laparoscopic cholecystectomy.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

This single-center, prospective observational study will be conducted at Samsun University Training and Research Hospital operating rooms between November 2025 and June 2026.

The study will include patients aged 18-75 years, classified as ASA I-III, who are scheduled for elective laparoscopic cholecystectomy and have provided written informed consent. For pain management, these patients will undergo either serratus intercostal plane block (SIPB) or external oblique plane block (EOPB) under ultrasound guidance. Patients receiving one of these two block techniques will be observed, and the sensory block areas created will be evaluated.

Both blocks will be performed bilaterally and under ultrasound guidance immediately before surgery. 0.25% bupivacaine will be used for the block applications, and 25 mL of local anesthetic will be injected into each side (a total of 50 mL). Thirty minutes after the block, patients will be evaluated for cutaneous sensory block using the "pinprick test." This evaluation will be standardized according to specific dermatome levels, covering the midline and both abdominal quadrants, in order to describe sensory loss on the skin.

The data obtained will be analyzed to determine the dermatomal spread and the minimum and maximum areas of effect of the blocks. Additionally, findings related to block application time will be recorded observationally. A comparison between the groups will be made, and the degree of overlap between the sensory block areas and the surgical incision site will be evaluated.

Study Type

Observational

Enrollment (Estimated)

40

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Turkey (Türkiye)
    • Ilkadım
      • Samsun, Ilkadım, Turkey (Türkiye), 55200
        • Recruiting
        • Samsun University, Samsun Training and Research Hospital
        • Contact:
          • Hatice Selçuk Kuşderci
          • Phone Number: 905052159896
        • Contact:
          • Mert Yilmaz
          • Phone Number: 905326699555

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Patients who are scheduled to undergo elective laparoscopic cholecystectomy surgery under general anesthesia at the Department of Anesthesiology, Samsun University Training and Research Hospital. A total of 40 patients will be enrolled and divided into two groups: EOPB (n=20) and SIPB (n=20). Each participant will receive ultrasound-guided regional anesthesia according to their assigned group, and sensory mapping will be performed postoperatively.

Description

Inclusion Criteria:

  • Patients scheduled for elective laparoscopic cholecystectomy surgery and who have received a regional anesthesia technique for this purpose.
  • Aged between 18-75 years.
  • Belonging to ASA I-III group.
  • Having provided written informed consent.

Exclusion Criteria:

  • Patients who refuse to participate.
  • Patients who did not receive a block.
  • Patients classified as ASA IV.
  • History of previous abdominal surgery (affecting the laparoscopic approach).
  • Patients with cognitive dysfunction or inability to cooperate.
  • Patients diagnosed with psychiatric disorders (schizophrenia, mania, depression, etc.).
  • Patients who have been using antipsychotic medication for more than 4 weeks.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
EOPB Group

Patients undergoing laparoscopic cholecystectomy who receive an ultrasound-guided External Oblique Plane Block (EOPB) for postoperative analgesia.

Bilateral blocks will be performed using 0.25% bupivacaine (25 mL per side, total 50 mL). Sensory block areas will be evaluated using pinprick at predefined time points.
Procedure: External Oblique Plane Block (EOPB)
Ultrasound-guided External Oblique Plane Block (EOPB) performed bilaterally using 0.25% bupivacaine (25 mL per side, total 50 mL) for postoperative analgesia in laparoscopic cholecystectomy.
SIPB Group

Patients undergoing laparoscopic cholecystectomy who receive an ultrasound-guided Serratus Intercostal Plane Block (SIPB) for postoperative analgesia.

Bilateral blocks will be performed using 0.25% bupivacaine (25 mL per side, total 50 mL). Sensory block areas will be evaluated using pinprick at predefined time points.
Procedure: Serratus Intercostal Plane Block (SIPB)
Ultrasound-guided Serratus Intercostal Plane Block (SIPB) performed bilaterally using 0.25% bupivacaine (25 mL per side, total 50 mL) for postoperative analgesia in laparoscopic cholecystectomy.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cutaneous Sensory Block Area of EOPB and SIPB
Time Frame: 30 minutes after block application
The primary outcome is the dermatomal mapping of the cutaneous sensory block areas produced by the serratus intercostal plane block (SIPB) and external oblique plane block (EOPB), and the comparison of sensory block extent between the two techniques.
30 minutes after block application

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Coverage of Surgical Port Entry Sites by the Sensory Block Area
Time Frame: 30 minutes after block application
After examination and mapping of the cutaneous sensory area, surgical port entry sites will be marked on the patient by the surgeon. Port entry sites covered and not covered by the sensory block area will be assessed and compared between the two groups on a percentage basis.
30 minutes after block application
Maximum and Minimum Spread of the Cutaneous Sensory Block Area
Time Frame: 30 minutes after block application
The minimum and maximum dermatomal boundaries of the cutaneous sensory block area produced by each regional anesthesia technique will be assessed using sensory mapping and compared between the two groups.
30 minutes after block application
Block Application Duration
Time Frame: From needle insertion to completion of local anesthetic injection
During regional anesthesia administration, the duration of block application will be measured in minutes for each technique and compared between the two groups.
From needle insertion to completion of local anesthetic injection

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Samsun University

Investigators

  • Principal Investigator: Hatice Selcuk Kusderci, M.D., Samsun University Training and Research Hospital

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

November 15, 2025

Primary Completion (Estimated)

May 15, 2026

Study Completion (Estimated)

June 1, 2026

Study Registration Dates

First Submitted

November 21, 2025

First Submitted That Met QC Criteria

February 25, 2026

First Posted (Actual)

March 3, 2026

Study Record Updates

Last Update Posted (Actual)

March 3, 2026

Last Update Submitted That Met QC Criteria

February 25, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • GOKAEK 2025/20/13

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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