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

Официальное название

Interscalene vs Phrenic-sparing Blocks in Obesity: Effect of Pre-operative Maximum Inspiratory Pressure in a Randomized Trial

Обзор

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).

Вмешательства

• Процедура Ultrasound-Guided Interscalene Brachial Plexus Block
  Single 16 mL injection (15 mL 0.5 % bupivacaine + 1 mL dexamethasone 4 mg) at the C5-C6 root level under ultrasound guidance. Performed pre-operatively as standard care for shoulder surgery. Arm Cross-Reference: Standard Interscalene Block (Control)
• Процедура Phrenic-Sparing Block Combination (Experimental)
  Infraclavicular: 15 mL (75 mg) 0.5 % bupivacaine + 1 mL dexamethasone (4 mg) injected around the cords of the brachial plexus beneath the clavicle under ultrasound guidance. Distal Suprascapular: 12 mL (60 mg) 0.5 % bupivacaine + 1 mL (4 mg) dexamethasone injected at the suprascapular notch under ultrasound guidance to provide complete shoulder coverage while minimizing phrenic nerve involvement. Total local anesthetic dose = 135 mg bupivacaine + 8 mg dexamethasone. Arm Cross-Reference: Phreni
• Препарат Bupivacaine HCl 0.5% Injectable Solution
  Infraclavicular: Adminstered as 15 mL (75 mg) injection (together with dexamethasone). Distal Suprascapular: Adminstered as 12 mL (60 mg) injection (together with dexamethasone).
• Препарат Dexamethasone 4mg
  Adminstered as applicable for infraclavicular and distal suprascapular: as 1 mL (4 mg) injection (together with bupicacaine 0.5%).

Первичные конечные точки

• Incidence of Early Postoperative Respiratory Compromise [Срок оценки: Within 60 minutes after arrival to PACU]
• Effect Modification by Preoperative Maximum Inspiratory Pressure (MIP) [Срок оценки: Baseline (preoperative MIP test) and PACU assessment (30-60 minutes post-surgery).]

Вторичные конечные точки (5)

• Lowest Oxygen Saturation (SpO₂) in PACU [Срок оценки: From PACU arrival to discharge (typically 60-120 minutes)]
• Total Duration of Supplemental Oxygen Use [Срок оценки: 0-24 hours post-surgery.]
• Post-Induction Opioid Consumption [Срок оценки: 0-6 hours post-surgery.]
• Diaphragmatic Excursion Change from Baseline [Срок оценки: Baseline (pre-block) and 30-60 minutes post-surgery in PACU.]
• PACU Pain Score [Срок оценки: Within 1 hour after PACU arrival.]

Критерии участия

Критерии включения

• 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).

Критерии исключения

• 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

Критерии приведены из реестра в оригинале (на английском). Окончательную оценку соответствия проводит исследовательский центр.

Здоровые добровольцы: Нет

Дизайн исследования

Распределение

Рандомизированное

Модель

Параллельные группы

Маскирование

Простое слепое

Основная цель

Лечение

Центры проведения

США · 1 центр

• University of North Carolina Hospitals — Chapel Hill

Идентификаторы

NCT: NCT07216820 · 23-3332

Первоисточники (государственные реестры)

• ClinicalTrials.gov (NIH, США)

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