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Nerve Blocks for Shoulder Surgery in Adults with Obesity

This study is looking at two types of nerve blocks for adults with obesity having shoulder surgery. It compares a standard nerve block (Ultrasound-Guided Interscalene Brachial Plexus Block) with a new approach called a Phrenic-Sparing Block Combination (using Bupivacaine HCl 0.5% and Dexamethasone 4mg). The goal is to see if the phrenic-sparing block can reduce breathing problems right after surgery and if a simple breathing test (Maximum Inspiratory Pressure, MIP) can help identify who might be at higher risk. Researchers will also check for similar pain control and opioid use. You may be able to join if you are 18 or older, have a BMI of 35 or higher, and are scheduled for elective shoulder surgery at UNC Hospitals.

Study design
This is an interventional study planning to enroll 68 participants. It compares two different nerve block procedures.
What's involved
You would undergo a preoperative breathing test (MIP) and receive one of the two nerve block procedures before your shoulder surgery. Your breathing will be assessed in the recovery room (PACU) and for 24 hours after surgery.
Compensation
Not stated in the trial record.
Follow-up
Your breathing will be assessed within 60 minutes of arriving in the recovery room (PACU) and for any breathing-related complications or unplanned admissions within 24 hours.

AI-generated from the public study record. Only the study team can confirm whether you're eligible — confirm details with them before making decisions.

NCT07216820

Interscalene vs Phrenic-sparing Blocks in Obesity and Effect of Maximum Inspiratory Pressure

Recruiting
NAAges 18+InterventionalTreatment
University of North Carolina, Chapel Hill
~68 participants
Updated 2026-01-28 on ClinicalTrials.gov
What's tested:Ultrasound-Guided Interscalene Brachial Plexus BlockPhrenic-Sparing Block Combination (Experimental)Bupivacaine HCl 0.5% Injectable SolutionDexamethasone 4mg

At a glance

Recruiting sites
1 of 1 listed site is recruiting right now
RecruitingSuspended, closed, or not yet open
What they're measuring
Incidence of Early Postoperative Respiratory Compromise
Measured over Within 60 minutes after arrival to PACU
+1 more outcome measured

Conditions

Shoulder Surgery
Obesity

Explore related trials

ObesityShoulder Surgery

Where it's being run

1 sites across 1 states
North Carolina1

Study leadership

  • Monika Nanda · PRINCIPAL_INVESTIGATOR · University of North Carollina at Chapel Hill

Who to contact

Monika Nanda
[email protected]
919-966-5136
Email the study team

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Do you actually qualify for this trial?

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Eligibility criteria

Inclusion

Age ≥ 18 years (self-report, confirmed on chart).
Body-mass index ≥ 35 kg m\^2 at the pre-operative clinic visit (chart).
Scheduled for elective unilateral shoulder surgery (arthroscopy, arthroplasty, rotator cuff repair, reverse arthroplasty) under general anesthesia at UNC Hospitals
Planned use of a single-injection regional brachial-plexus block for postoperative analgesia (anesthesia record).
Able to perform a maximal-inspiratory-pressure (MIP) maneuver at screening, producing two reproducible efforts (bedside test)
Able to read or understand English and provide written informed consent (consent discussion).

Exclusion

Emergent or trauma shoulder procedure or case converted to open surgery (schedule/chart).
Pregnancy confirmed by point-of-care urine test on day of surgery (POC test). Prisoner status or legal incapacity to consent (chart/interview).
Severe pulmonary disease: GOLD stage 3-4 COPD, restrictive lung disease unrelated to obesity with FVC \< 50 % predicted, baseline dyspnea Borg ≥ 3, or home oxygen therapy (pulmonary clinic notes, patient interview).
Severe heart disease- Severe valvular heart disease, Congestive Heart Failure NYHA Class III or IV, Obstructive Coronary Artery Disease with Angina
Neuromuscular disorders affecting respiratory muscles (e.g., ALS, myasthenia gravis) or known diaphragmatic paralysis (chart).
Coagulopathy (platelets \< 100 × 10/ L or INR \> 1.5) or local infection at block sites (pre-op labs/assessment).
Anemia and hemoglobinopathies: Hgb \<10 g/dl, clinically significant hemoglobinopathy.
Allergy to bupivacaine, dexamethasone, or ultrasound gel (self-report).
Chronic opioid use \> 100 mg oral-morphine equivalents per day in the three months preceding surgery (medication history, PDMP query).
Prior enrolment in this trial or planned participation in another interventional study that might confound outcomes (research registry).
Anticipated inability to comply with postoperative assessments (e.g., profound cognitive impairment, expected early transfer to outside facility) as judged by the investigator

What this trial measures

  • Incidence of Early Postoperative Respiratory CompromiseWithin 60 minutes after arrival to PACU

    Composite outcome defined as either (a) a Modified Borg Dyspnea Score ≥ 3 in the post-anesthesia care unit (PACU, 30-60 minutes after surgery) or (b) continued need for supplemental oxygen at the PACU assessment. Outcome Type: Primary Unit of Measure: Percentage of participants meeting composite endpoint.

  • Effect Modification by Preoperative Maximum Inspiratory Pressure (MIP)Baseline (preoperative MIP test) and PACU assessment (30-60 minutes post-surgery).

    Assess whether the magnitude of treatment benefit from the phrenic-sparing block varies by baseline inspiratory-muscle strength. The effect is modeled as the interaction between block type and continuous MIP (cm H₂O) on the composite respiratory-compromise endpoint. Unit of Measure: Interaction odds ratio (per 10 cm H₂O decrement in MIP).