Shoulder Pericapsular Block Versus Interscalene Block in Arthroscopic Shoulder Surgery

March 18, 2026 updated by: Beliz Bilgili, Marmara University

Ultrasound-Guided Interscalene Block Versus Shoulder Pericapsular Nerve Group (PENG) Block for Hemidiaphragmatic Paralysis in Elective Shoulder Surgery: A Randomized Controlled Trial

This randomized controlled trial aims to compare the incidence of hemidiaphragmatic paralysis (HDP) following ultrasound-guided interscalene block (ISB) versus shoulder pericapsular nerve group (PENG) block in patients undergoing elective shoulder surgery under general anesthesia.

The primary objective is to determine whether the shoulder PENG block reduces the incidence of HDP compared with conventional intrafascial ISB. HDP will be assessed using ultrasound measurement of diaphragmatic excursion 30 minutes after block performance

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Detailed Description

Interscalene block is widely used for shoulder surgery but is frequently associated with ipsilateral hemidiaphragmatic paralysis due to phrenic nerve involvement. The shoulder PENG block is a more distal pericapsular technique targeting articular branches and may reduce diaphragmatic impairment.

This prospective, parallel-group, randomized controlled trial will enroll 68 adult patients scheduled for elective shoulder surgery. Participants will be randomly assigned (1:1) to receive either ultrasound-guided intrafascial interscalene block or ultrasound-guided shoulder PENG block.

Both groups will receive 15 mL of 0.25% bupivacaine (total dose 37.5 mg). Diaphragmatic excursion will be measured at baseline and 30 minutes after block performance using M-mode ultrasonography by a blinded assessor.

The primary endpoint is hemidiaphragmatic paralysis defined as ≥25% reduction in diaphragmatic excursion from baseline. Partial and complete paralysis will be analyzed as a composite binary outcome.

Study Type

Interventional

Enrollment (Estimated)

70

Phase

  • Not Applicable

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

Description

Inclusion Criteria:

  • ASA physical status I-III
  • Scheduled for elective shoulder surgery under general anesthesia
  • Able to provide informed consent

Exclusion Criteria:

  • Pre-existing diaphragmatic dysfunction
  • Severe COPD or restrictive pulmonary disease
  • Neuromuscular disorders
  • BMI > 40 kg/m²
  • Coagulopathy
  • Infection at injection site
  • Allergy to local anesthetics
  • Inability to undergo diaphragmatic ultrasound assessment

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

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Active Comparator: Shoulder PENG Block
Procedure: Ultrasound-guided shoulder pericapsular nerve group block Drug: 15 mL of 0.25% bupivacaine (37.5 mg)
Other: shoulder pericapsular nerve group block
Procedure: Ultrasound-guided shoulder pericapsular nerve group block Drug: 15 mL of 0.25% bupivacaine (37.5 mg)
Active Comparator: Interscalene Block (ISB)
Procedure: Ultrasound-guided conventional intrafascial interscalene block at C5-C6 level Drug: 15 mL of 0.25% bupivacaine (37.5 mg)
Other: Interscalene Nerve Block
Procedure: Ultrasound-guided conventional intrafascial interscalene block at C5-C6 level Drug: 15 mL of 0.25% bupivacaine (37.5 mg)

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Hemidiaphragmatic Paralysis (HDP)
Time Frame: 30 minutes after block performance
≥25% reduction in diaphragmatic excursion from baseline measured by ultrasound M-mode.
30 minutes after block performance

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Complete hemidiaphragmatic paralysis (≥75% reduction or paradoxical motion)
Time Frame: 30 minutes after block performance
≥75% reduction or paradoxical motion
30 minutes after block performance
Absolute and percentage change in diaphragmatic excursion
Time Frame: 30 minutes after block performance
change in diaphragmatic excursion
30 minutes after block performance
Total 24-hour tramadol consumption (mg)
Time Frame: postoperative 24 hours
Total 24-hour tramadol consumption (mg)
postoperative 24 hours
NRS pain scores (from 0 to 10: 0 stands for no pain, 10 stands for severe pain)
Time Frame: postopertaive 2 hours, 6 hours, 12 hours, 24 hours
Postoperative pain scores
postopertaive 2 hours, 6 hours, 12 hours, 24 hours
Rescue morphine consumption (mg)
Time Frame: postoperative 24 hours
Rescue morphine consumption (mg)
postoperative 24 hours

Collaborators and Investigators

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

Sponsor

Marmara University

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 (Estimated)

April 1, 2026

Primary Completion (Estimated)

October 1, 2026

Study Completion (Estimated)

December 1, 2026

Study Registration Dates

First Submitted

February 24, 2026

First Submitted That Met QC Criteria

March 18, 2026

First Posted (Actual)

March 20, 2026

Study Record Updates

Last Update Posted (Actual)

March 20, 2026

Last Update Submitted That Met QC Criteria

March 18, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Other Study ID Numbers

  • Shoulder Pericapsular Block

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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