NCT07216820Recruiting
Interscalene vs Phrenic-sparing Blocks in Obesity and Effect of Maximum Inspiratory Pressure
Interscalene vs Phrenic-sparing Blocks in Obesity: Effect of Pre-operative Maximum Inspiratory Pressure in a Randomized Trial
Source: ClinicalTrials.gov · Last updated 28 Jan 2026
Brief summary (registry, in English)
The goal of this clinical trial is to learn whether a phrenic-sparing nerve block can lower early breathing problems after shoulder surgery in adults with obesity, and whether a simple breathing-strength test (maximum inspiratory pressure, MIP) helps identify who is at higher risk. The main questions are: Does the phrenic-sparing approach reduce breathlessness or oxygen need in the recovery room (30-60 minutes after arrival)? Do patients have similar pain control and opioid use compared with the standard interscalene block (ISB)? Are there any breathing-related complications or unplanned admissions within 24 hours? Researchers will compare the phrenic-sparing block (infraclavicular + distal suprascapular) to the standard ISB, both commonly used at UNC. Participants will: Have a quick MIP breath test before surgery (and, if age ≥65, a brief thigh muscle ultrasound). Be randomly assigned to receive either the standard ISB or the phrenic-sparing block (both ultrasound-guided and part of routine care). Receive usual anesthesia/surgery; have a brief recovery check at 30-60 minutes (breathlessness score, oxygen use, oxygen level). Have pain medicines recorded from anesthesia start to PACU discharge; the team may review the chart up to 24 hours and make a short follow-up call (24-48 hours).
- Status (registry)
- Recruiting
- Study type
- Interventional
- Enrollment
- 68 (estimated)
- First submitted
- 13 Oct 2025
- Start date
- 21 Jan 2026
- Primary completion date
- 1 Nov 2027
- Lead sponsor
- University of North Carolina, Chapel Hill
- Diseases
- Obesity
- NCT number
- NCT07216820
What you commit to
- Study type: Interventional
- Planned participants: 68
- From 21 Jan 2026 to the primary completion date, 1 Nov 2027
- 1 site in 1 country
- Visits and tests: ask the trial team, the registry does not list them
Built from the registry fields of ClinicalTrials.gov. It describes the study, not your situation.
Who cannot take part
Copied verbatim from ClinicalTrials.gov and grouped by topic. Only the trial team decides who can take part.
Prior treatment
- 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).
- 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).
Other illness
- 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).
- Allergy to bupivacaine, dexamethasone, or ultrasound gel (self-report).
- Anticipated inability to comply with postoperative assessments (e.g., profound cognitive impairment, expected early transfer to outside facility) as judged by the investigator
Lab values
- 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.
Who the study is looking for
- 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).
Age in the registry: 18 years to - · Sex: All · Does not accept healthy volunteers
Sites (1)
Sites in registry order. Pick your city on the disease page to sort them by distance.
| Site | City | Country | Site status |
|---|---|---|---|
| University of North Carolina Hospitals Coordinator of this site? Confirm its status | Chapel Hill | United States | Recruiting |
This page is information, not medical advice. Discuss any trial with your doctor.