An interventional study of Ultrasound-Guided Interscalene Nerve Block and ltrasound-Guided Combined Suprascapular and Axillary Nerve Blocks in Cerebral Oxygenation During Shoulder Arthroscopy, sponsored by Ataturk University. Recruiting at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-11-12.
Sponsored by Ataturk University · Not applicable, Interventional, and Treatment
Shoulder arthroscopy is often performed with the patient in an upright beach-chair position. Changes in position and anesthesia may affect blood pressure and oxygen delivery to the brain. This study compares two ultrasound-guided nerve block approaches performed before general anesthesia: interscalene block and combined suprascapular and axillary nerve blocks. Participants will be randomly assigned to one of these approaches. Both groups will receive the same general anesthetic and 20 mL of 0.25% bupivacaine for the assigned block approach. Cerebral oxygen saturation will be monitored continuously using sensors placed on the forehead. The main outcome is the total cerebral desaturation burden, measured as the area below 80% of each participant's baseline cerebral oxygen saturation during monitoring. Other outcomes include the occurrence and duration of desaturation, minimum cerebral oxygen saturation, blood pressure and heart rate events, vasopressor use, and immediate recovery and a Mini-Mental State Examination to assess cognitive functions.
Ataturk University is the lead sponsor of 460 studies on the registry; 126 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Participants will receive a preoperative ultrasound-guided interscalene nerve block using 20 mL of 0.25% bupivacaine.
Procedure: Ultrasound-Guided Interscalene Nerve Block
Participants will receive preoperative ultrasound-guided suprascapular and axillary nerve blocks. A total of 20 mL of 0.25% bupivacaine will be divided between the two blocks.
Procedure: ltrasound-Guided Combined Suprascapular and Axillary Nerve Blocks
A preoperative ultrasound-guided interscalene block will be performed with the patient supine and the head turned to the opposite side. A total of 20 mL of 0.25% bupivacaine will be injected around the brachial plexus roots.
Preoperative ultrasound-guided suprascapular and axillary nerve blocks will be performed. A total of 20 mL of 0.25% bupivacaine will be divided between the two block sites.
Total Cerebral Desaturation Burden (AUC)
The area under the curve below the desaturation threshold, defined as 80% of baseline regional cerebral oxygen saturation (rSO₂). AUC will be calculated separately for each hemisphere; the mean of the two hemispheres will be used for the primary comparison. Only desaturation episodes lasting at least 15 seconds will be included. The unit is %·min.
Time frame: From baseline measurement before the nerve block until 10 minutes after return to the supine position.
Incidence and Number of Cerebral Desaturation Events
Proportion of participants with, and number of, cerebral desaturation events, defined as a decrease in rSO₂ of at least 20% from baseline lasting at least 15 seconds.
Time frame: From baseline measurement before the nerve block until 10 minutes after return to the supine position.
Total Time Below the Cerebral Desaturation Threshold
Total time during which rSO₂ remains below 80% of baseline.
Time frame: From baseline measurement before the nerve block until 10 minutes after return to the supine position.
Minimum Right and Left Cerebral rSO₂
Minimum rSO₂ values recorded from the right and left frontal hemispheres; values will be assessed separately.
Time frame: From baseline measurement before the nerve block until 10 minutes after return to the supine position.
Ipsilateral and Contralateral Cerebral Desaturation Burden
AUC below the desaturation threshold in the cerebral hemisphere ipsilateral and contralateral to the operated shoulder.
Time frame: From baseline measurement before the nerve block until 10 minutes after return to the supine position.
Incidence of Intraoperative Hypotension and Bradycardia
Proportion of participants with hypotension, defined as a decrease in baseline systolic blood pressure of more than 20% or MAP below 65 mmHg, and bradycardia, defined as heart rate below 50 beats/min.
Time frame: During the intraoperative period.
Total Intraoperative Ephedrine and Norepinephrine Dose
Total ephedrine dose in mg and total norepinephrine dose in µg administered intraoperatively.
Time frame: During the intraoperative period.
Post-Anesthesia Care Unit Length of Stay
Time elapsed, in minutes, from postoperative admission to the post-anesthesia care unit to discharge to the surgical ward. Patients are discharged when the Modified Aldrete Score reaches 9 or higher.
Time frame: Perioperative period (immediate postoperative recovery, from post-anesthesia care unit admission to discharge).
Modified Aldrete Score at Post-Anesthesia Care Unit Discharge
The Modified Aldrete Score is recorded at discharge from the post-anesthesia care unit to the surgical ward. The scale assesses activity, respiration, circulation, consciousness, and oxygen saturation. Each component is scored from 0 to 2, yielding a total score ranging from 0 to 10. Higher scores indicate better physiological recovery from anesthesia. Patients are discharged when the total score reaches 9 or higher.
Time frame: Perioperative period (at discharge from the post-anesthesia care unit).
Assessment of cognitive functions at the 24th postoperative hour
A Mini-Mental State Examination was performed at the 24th postoperative hour to assess cognitive functions.
Time frame: At the 24th postoperative hour
Plan to share: No
Started Nov 2026 (actual). Primary completion is estimated for Dec 2026, 1 month after the start.
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From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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