Comparison of the Effects of Interscalene Block and Superior Trunk Block on Pulmonary Functions

NCT06703281 | Completed

• 1 other identifier: 262d4590-e298-4dfe
• Study Type: interventional
• Target: 123
• Locations: 1 country
• Sites: 1

Brief Summary

The interscalene block (ISB) is one of the peripheral nerve blocks providing surgical anesthesia and postoperative analgesia in shoulder arthroscopy, eliminating the need for general anesthesia. It is performed by administering local anesthetics (LA) to the C5-C6 roots between the scalene muscles at the level of the cricoid cartilage. ISB-related side effects, such as diaphragmatic paralysis, can occur with the spread of LA to the phrenic nerve over the anterior scalene muscle. To prevent this, a superior trunk block (STB) can be performed by administering LA close to the supraclavicular region where the C5-C6 roots merge into the superior trunk (further away from the phrenic nerve). Although there are studies in the literature demonstrating diaphragmatic paralysis using ultrasound and/or spirometry, no study evaluating diaphragmatic paralysis simultaneously with both ultrasound and spirometry under regional anesthesia alone has been found. Therefore, in this study, the investigators aim to assess the effects of this side effect on diaphragmatic excursion using ultrasound simultaneously and on respiratory functions using spirometry.

Conditions

Regional Anesthesia Morbidity; Complication Following Peripheral Nerve Block; Phrenic Nerve Paralysis

Keywords

Ultrasound-Guided Nerve or Plane Block; Phrenic Nerve Sparing; Brachial Plexus Block

Outcome Measures

Primary Outcomes (1)

• Rate of Hemidiaphragmatic Paralysis

  Measurement of diaphragmatic excursion (DE) in centimeters using ultrasound during normal and deep breathing. The primary aim is to compare the percentage change in DE between interscalene block (ISB) and superior trunk block (STB) groups. Diagnosis of hemidiaphragmatic paralysis based on diaphragmatic excursion reduction: ≥75% reduction classified as complete paralysis, 25-74% reduction as partial paralysis, and ≤25% reduction as no paralysis.

  Baseline (pre-block) and 30 minutes post-block.

Secondary Outcomes (3)

• Percentage Change in Forced Expiratory Volume in 1 Second (FEV1) and Forced Vital Capacity (FVC)

  Baseline (pre-block) and 30 minutes post-block.

• Percentage Change in FEV1/FVC Ratio

  Baseline (pre-block) and 30 minutes post-block.

• Number of Participants Requiring Additional Analgesics

  Intraoperative period and within 24 hours postoperatively.

Study Arms (2)

Interscalene brachial plexus block

EXPERIMENTAL

Patients who underwent shoulder arthroscopic surgery and recieved interscalene brachial plexus block for anesthesia before surgery

Procedure: Interscalene Nerve Block

Superior trunk brachial plexus block

EXPERIMENTAL

Patients who underwent shoulder arthroscopic surgery and recieved superior trunk brachial plexus block for anesthesia before surgery

Procedure: Superior trunk block

Interventions

Interscalene Nerve Block PROCEDURE

Patients assigned to the Interscalene Nerve Block would have spirometry and ultrasound-guided diaphragm excursion measurements both pre and post-blok 30 minutes.

Also known as: Spirometry, Ultrasound

Interscalene brachial plexus block

Superior trunk block PROCEDURE

Patients assigned to the Superior Trunk Nerve Block would have spirometry and ultrasound-guided diaphragm excursion measurements both pre and post-blok 30 minutes.

Also known as: spirometry, ultrasound

Superior trunk brachial plexus block

Eligibility Criteria

• Age: 18 Years - 80 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Patients scheduled for elective shoulder arthroscopic surgery.
• Age between 18 and 80 years.
• American Society of Anesthesiologists (ASA) physical status I-III.
• Written informed consent obtained.

You may not qualify if:

• Refusal to undergo peripheral nerve block.
• Pre-existing peripheral nerve disorders.
• Known respiratory, hepatic, renal, or cardiovascular diseases.
• Allergy to local anesthetics.
• Active infection at the block site.
• Body mass index (BMI) \> 40 kg/m².
• Coagulopathy or current anticoagulant therapy.
• Sepsis or systemic infection.
• History of prior surgery at the intended block site.
• Neurological deficits or psychiatric disorders affecting cooperation.
• Inability to perform spirometry or comply with study procedures.

Sponsors & Collaborators

• Gazi University: lead

Study Sites (1)

Gazi University School of Medicine

Ankara, 06560, Turkey (Türkiye)

Location

MeSH Terms

Interventions

High-Energy Shock Waves

Intervention Hierarchy (Ancestors)

Ultrasonic Waves; Sound; Radiation, Nonionizing; Radiation; Physical Phenomena

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: OUTCOMES ASSESSOR
• Masking Details: The investigator who measures the diaphragmatic excursions and spirometric parameters would be blind to the block type performed.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: MD

Study Record Dates

• First Submitted: November 21, 2024
• First Posted: November 25, 2024
• Study Start: December 1, 2024
• Primary Completion: January 11, 2025
• Study Completion: January 31, 2025
• Last Updated: December 19, 2025

Record last verified: 2025-12

Locations

TU (1)