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
Who can join
As published by the study on ClinicalTrials.gov. "Not stated" means the study hasn't said — ask the study team.
- Age
- 18 Years and older
- Sex
- All sexes
- Healthy volunteers
- Not accepted
- Compensation
- Not stated
Other requirements are listed under Eligibility below. Only the study team can confirm whether you can join.
What to expect
No one can promise a trial will help you personally — that is what the research is trying to find out.
What participation involves
- Procedures mentioned: Ultrasound
Only what the study's summary and detailed description on ClinicalTrials.gov say. Time periods may describe the whole study or a part of it — ask the study team what applies to you.
Show the study's own words
- "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)."
- Compensation
- Not stated
- Study-related exams and procedures are typically provided at no cost. This is how many trials work in general — confirm the details for this study with the study team.
- Participants are monitored closely by the research team throughout the study.
- Some participants may receive access to an investigational treatment, which is still being studied.
- Your participation helps researchers learn whether this approach could help future patients.
About this study
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).
Compensation is read from the study's own description and may be missing — always confirm with the study team.
Eligibility
Official eligibility criteria
Inclusion Criteria: * 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 Criteria: * 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
Study sites (1)
NC
- University of North Carolina Hospitals · Chapel Hill, NC 27599Monika Nanda · Study contact · 919-966-5136 · mnanda@aims.unc.eduMore trials in Chapel Hill