Regional Anesthesia MorbidityNCT06703281
Comparison of the Effects of Interscalene Block and Superior Trunk Block on Pulmonary Functions
A study testing Interscalene Nerve Block and Superior trunk block in people with Regional Anesthesia Morbidity and Complication Following Peripheral Nerve Block, run by Gazi University at 1 site in Turkey (Türkiye).
Trial 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. Read more about this study
- Who is it for?
- Ages 18 to 80 years
- Conditions the study is for
- Regional Anesthesia Morbidity, Complication Following Peripheral Nerve Block, Phrenic Nerve Paralysis
- What is being tested?
- Interscalene Nerve Block and Superior trunk block
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 123 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Dec 2024to 31 Jan 2025
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 80 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- 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.
Who cannot join
- 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.
Show all 11Show fewer
- 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.
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Gazi University School of Medicine
Ankara, 06560
About this study
Official title: Comparison of the Effects of Interscalene Block and Superior Trunk Block on Pulmonary Functions for Shoulder Arthroscopic Surgery Patients
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.
Read the detailed description
Due to diaphragmatic paralysis, interscalene block (ISB) application is contraindicated in patients with pulmonary issues, leaving general anesthesia as the only option. However, the use of opioids for postoperative analgesia in such patients brings unwanted opioid side effects. Consequently, new approaches have emerged to prevent diaphragmatic paralysis, making peripheral blocks feasible for shoulder arthroscopies in patients with pulmonary problems. This study aims to reassess the hypothesis regarding ISB and superior trunk block (STB), routinely used for shoulder arthroscopy surgery, in patients without pulmonary issues, supported by simultaneous ultrasound measurements of diaphragmatic excursion and spirometry measurements of respiratory function. Additionally, the demographic characteristics of patients, onset time of block effects, postoperative additional analgesic requirements, durations of block effects, and times of initial analgesic needs will be observed and compared.
Research Type Description: The study is prospective randomized research. Respiratory function measurements will be taken from patients undergoing ISB and STB, which are routinely performed in brachial plexus blocks in our clinic. These measurements do not involve any invasive procedures and will be solely quantitatively assessed using ultrasound and respiratory function tests.
Case Report Form: The form that will be used is a case report form. Each participant will be assigned a unique number, and all sections related to the study will be completed for each participant.
Data Collection:
After obtaining consent from patients agreeing to participate in the study, patients will be monitored (blood pressure, heart rate, oxygen saturation), and intravenous access will be established.
Dr. Beyza Mehri Büyükgebiz Yeşil will measure diaphragmatic excursion under ultrasound guidance during deep and normal respiration on the side where the block will be performed and record the values in the case report form.
Dr. Beyza Mehri Büyükgebiz Yeşil will perform respiratory function testing with a spirometer and record the values in the case report form.
The blocks will be administered by Assoc Prof Dr. Gökçen Emmez and Prof Dr. İrfan Güngör.
Thirty minutes after the end of the block application, Dr. Beyza Mehri Büyükgebiz Yeşil will measure diaphragmatic excursion under ultrasound guidance during deep and normal respiration on the side where the block was performed and perform respiratory function testing with a spirometer and record the values in the case report form.
Blinding of the study will be ensured by having different researchers perform the block and measurements.
Prof Ulunay Kanatlı will perform the surgical procedure. Patients will be prescribed 3X1 grams of Paracetamol for routine postoperative analgesia.
The onset time of the block effect, postoperative additional analgesic requirements, duration of block effects, and time of initial analgesic needs will be observed and recorded in the case report form.
Both surgeon and patient satisfaction will be recorded in the case report form at the end of surgery. Patients will be contacted by phone one week after discharge to inquire about their current condition.
Data Analysis:
At the end of the study, data will be evaluated via case report forms and interpreted using appropriate statistical methods.
Diaphragmatic excursion change rates will be interpreted and analyzed by Prof. Dr. İrfan Güngör and Prof. Dr. Berrin Günaydın, and respiratory function values from the spirometer will be interpreted and analyzed by Prof. Dr. İpek Kıvılcım Oğuzülgen.
If continuous variables follow a normal distribution, the Student's T-test will be applied; if they do not follow a normal distribution, the Mann-Whitney U test will be applied. The Chi-square test will be applied to compare ratios. Depending on whether the data follows a normal distribution or not, Spearman or Pearson correlation tests will be applied for correlation evaluation. A p value of less than 0.05 will be considered statistically significant. Data will be presented as mean ± standard deviation, median, and n.
- Conditions
- Regional Anesthesia Morbidity, Complication Following Peripheral Nerve Block, Phrenic Nerve Paralysis
- Being tested
- Interscalene Nerve Block, Superior trunk block
- Keywords
- Ultrasound-Guided Nerve or Plane Block, Phrenic Nerve Sparing, Brachial Plexus Block
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Interscalene Nerve BlockProcedure or surgery
Also called Spirometry, Ultrasound
Patients assigned to the Interscalene Nerve Block would have spirometry and ultrasound-guided diaphragm excursion measurements both pre and post-blok 30 minutes.
Superior trunk blockProcedure or surgery
Also called spirometry, ultrasound
Patients assigned to the Superior Trunk Nerve Block would have spirometry and ultrasound-guided diaphragm excursion measurements both pre and post-blok 30 minutes.
| Study group | Role | What they receive |
|---|---|---|
| Interscalene brachial plexus block | Experimental | Patients who underwent shoulder arthroscopic surgery and recieved interscalene brachial plexus block for anesthesia before surgery Receives: 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 Receives: Procedure: Superior trunk block |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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)
Evaluation of the percentage change in FEV1 and FVC measured with spirometry between ISB and STB groups.
Measured: Baseline (pre-block) and 30 minutes post-block.
Percentage Change in FEV1/FVC Ratio
Evaluation of the percentage change in FEV1/FVC ratio measured with spirometry between ISB and STB groups.
Measured: Baseline (pre-block) and 30 minutes post-block.
Number of Participants Requiring Additional Analgesics
Comparison of additional analgesic requirements (e.g., opioids or local anesthetics) between the ISB and STB groups.
Measured: Intraoperative period and within 24 hours postoperatively.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Nov 2024
- Study start1 Dec 2024
- Primary completion11 Jan 2025
- Study completion31 Jan 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Regional Anesthesia MorbidityStudies of the same condition, open and under way.
- More trials run by Gazi UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Outcomes assessor
- Enrolment
- 123 participants (actual)
Sponsor and investigators
- Lead sponsor
- Gazi University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Beyza Büyükgebiz Yeşil, Gazi University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT06703281
- Sponsor's protocol ID
- 262d4590-e298-4dfe
- Status last verified
- Dec 2025
- First submitted
- 21 Nov 2024
- Last updated
- 19 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Buyukgebiz Yesil B, Emmez G, Kanatli U, Oguzulgen IK, Gunaydin B, Gungor I. Impact of interscalene versus superior trunk blocks as sole anesthetics on respiratory outcomes for shoulder arthroscopy: a randomized controlled trial. BMC Anesthesiol. 2026 Jan 14;26(1):106. doi: 10.1186/s12871-025-03575-0.
PubMed 41530734
Study at a glance
From the registry record, last updated by the sponsor on 19 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Comparison of the Effects of Interscalene Block and Superior Trunk Block on Pulmonary Functions for Shoulder Arthroscopic Surgery Patients
- ClinicalTrials.gov ID
- NCT06703281
- Acronym / sponsor ID
- 262d4590-e298-4dfe
- 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
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 123 participants (actual)
- Lead sponsor
- Gazi UniversityUniversity, hospital or other
- Study start
- 1 Dec 2024 (actual)
- Primary completion
- 11 Jan 2025 (actual)
- Study completion
- 31 Jan 2025 (actual)
- First posted
- 25 Nov 2024 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
Detailed description
Due to diaphragmatic paralysis, interscalene block (ISB) application is contraindicated in patients with pulmonary issues, leaving general anesthesia as the only option. However, the use of opioids for postoperative analgesia in such patients brings unwanted opioid side effects. Consequently, new approaches have emerged to prevent diaphragmatic paralysis, making peripheral blocks feasible for shoulder arthroscopies in patients with pulmonary problems. This study aims to reassess the hypothesis regarding ISB and superior trunk block (STB), routinely used for shoulder arthroscopy surgery, in patients without pulmonary issues, supported by simultaneous ultrasound measurements of diaphragmatic excursion and spirometry measurements of respiratory function. Additionally, the demographic characteristics of patients, onset time of block effects, postoperative additional analgesic requirements, durations of block effects, and times of initial analgesic needs will be observed and compared.
Research Type Description: The study is prospective randomized research. Respiratory function measurements will be taken from patients undergoing ISB and STB, which are routinely performed in brachial plexus blocks in our clinic. These measurements do not involve any invasive procedures and will be solely quantitatively assessed using ultrasound and respiratory function tests.
Case Report Form: The form that will be used is a case report form. Each participant will be assigned a unique number, and all sections related to the study will be completed for each participant.
Data Collection:
After obtaining consent from patients agreeing to participate in the study, patients will be monitored (blood pressure, heart rate, oxygen saturation), and intravenous access will be established.
Dr. Beyza Mehri Büyükgebiz Yeşil will measure diaphragmatic excursion under ultrasound guidance during deep and normal respiration on the side where the block will be performed and record the values in the case report form.
Dr. Beyza Mehri Büyükgebiz Yeşil will perform respiratory function testing with a spirometer and record the values in the case report form.
The blocks will be administered by Assoc Prof Dr. Gökçen Emmez and Prof Dr. İrfan Güngör.
Thirty minutes after the end of the block application, Dr. Beyza Mehri Büyükgebiz Yeşil will measure diaphragmatic excursion under ultrasound guidance during deep and normal respiration on the side where the block was performed and perform respiratory function testing with a spirometer and record the values in the case report form.
Blinding of the study will be ensured by having different researchers perform the block and measurements.
Prof Ulunay Kanatlı will perform the surgical procedure. Patients will be prescribed 3X1 grams of Paracetamol for routine postoperative analgesia.
The onset time of the block effect, postoperative additional analgesic requirements, duration of block effects, and time of initial analgesic needs will be observed and recorded in the case report form.
Both surgeon and patient satisfaction will be recorded in the case report form at the end of surgery. Patients will be contacted by phone one week after discharge to inquire about their current condition.
Data Analysis:
At the end of the study, data will be evaluated via case report forms and interpreted using appropriate statistical methods.
Diaphragmatic excursion change rates will be interpreted and analyzed by Prof. Dr. İrfan Güngör and Prof. Dr. Berrin Günaydın, and respiratory function values from the spirometer will be interpreted and analyzed by Prof. Dr. İpek Kıvılcım Oğuzülgen.
If continuous variables follow a normal distribution, the Student's T-test will be applied; if they do not follow a normal distribution, the Mann-Whitney U test will be applied. The Chi-square test will be applied to compare ratios. Depending on whether the data follows a normal distribution or not, Spearman or Pearson correlation tests will be applied for correlation evaluation. A p value of less than 0.05 will be considered statistically significant. Data will be presented as mean ± standard deviation, median, and n.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Interscalene brachial plexus block | Experimental | Procedure: Interscalene Nerve BlockPatients who underwent shoulder arthroscopic surgery and recieved interscalene brachial plexus block for anesthesia before surgery |
| Superior trunk brachial plexus block | Experimental | Procedure: Superior trunk blockPatients who underwent shoulder arthroscopic surgery and recieved superior trunk brachial plexus block for anesthesia before surgery |
Who may qualify
- Ages
- 18 to 80 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- 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.
Key exclusion criteria (11 listed)
- 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.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Interscalene Nerve BlockAlso: Spirometry, UltrasoundPatients assigned to the Interscalene Nerve Block would have spirometry and ultrasound-guided diaphragm excursion measurements both pre and post-blok 30 minutes. | Procedure or surgery | Interscalene brachial plexus block |
| Superior trunk blockAlso: spirometry, ultrasoundPatients assigned to the Superior Trunk Nerve Block would have spirometry and ultrasound-guided diaphragm excursion measurements both pre and post-blok 30 minutes. | Procedure or surgery | Superior trunk brachial plexus block |
Primary outcome
Rate of Hemidiaphragmatic Paralysis
Time frame: Baseline (pre-block) and 30 minutes post-block.
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.
3 secondary outcomes
Percentage Change in Forced Expiratory Volume in 1 Second (FEV1) and Forced Vital Capacity (FVC)
Time frame: Baseline (pre-block) and 30 minutes post-block.
Percentage Change in FEV1/FVC Ratio
Time frame: Baseline (pre-block) and 30 minutes post-block.
Number of Participants Requiring Additional Analgesics
Time frame: Intraoperative period and within 24 hours postoperatively.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Dec 2025.
- Derived from this study: PubMed 41530734Buyukgebiz Yesil B, Emmez G, Kanatli U, Oguzulgen IK, Gunaydin B, Gungor I. Impact of interscalene versus superior trunk blocks as sole anesthetics on respiratory outcomes for shoulder arthroscopy: a randomized controlled trial. BMC Anesthesiol. 2026 Jan 14;26(1):106. doi: 10.1186/s12871-025-03575-0.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Interscalene Nerve Block and Superior trunk block in people with Regional Anesthesia Morbidity and Complication Following Peripheral Nerve Block, run by Gazi University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 19 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Rate of Hemidiaphragmatic Paralysis (time frame: Baseline (pre-block) and 30 minutes post-block.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT06703281, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Dec 2025.