Comparison of the Interscalene Block Alone Versus Combined With Superior Truncus Block During Shoulder Surgery in Diaphragmatic Function

NCT ID: NCT07338630

Last Updated: 2026-01-20

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 60 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2026-01-01
• Study Completion Date: 2027-06-01

Brief Summary

Primarily, This study aims to compare between interscalene block alone versus combined with superior truncus block in producing diaphragmatic paralysis and Secondarily aims to evaluate

1. Effect on the pulmonary function.

2. Duration of the sensory and motor block.

3. Postoperative analgesic consumption.

4. Any complications or side effects during shoulder surgery.

Detailed Description

Regional anesthesia is central to modern shoulder surgery because it provides excellent perioperative analgesia, reduces opioid consumption, and facilitates early rehabilitation. The interscalene brachial plexus block (ISB) has long been considered the gold-standard single-shot regional technique for shoulder procedures due to its reliable analgesia and surgical anesthesia. However, ISB commonly causes ipsilateral hemidiaphragmatic paresis (HDP) from unintended phrenic nerve blockade, which can produce clinically important declines in pulmonary function and may be poorly tolerated in patients with limited respiratory reserve.

To minimize phrenic involvement while preserving analgesic effectiveness, more selective approaches have been proposed. The superior trunk block (STB) - performed at the level where C5-C6 fibers form the superior trunk - aims to anesthetize the shoulder innervation more distally and thus reduce spread to the phrenic nerve. A landmark randomized trial and subsequent studies reported that STB provides analgesia comparable to ISB while greatly lowering the incidence of HDP (for example, ISB 71% vs STB 5% in one trial). Systematic reviews and meta-analyses since then have reinforced STB as an effective phrenic-sparing alternative for many shoulder procedures.

Despite encouraging data for STB, the literature is not entirely uniform. Some randomized trials and observational reports have found either reduced anesthetic quality with STB or smaller-than-expected reductions in phrenic involvement, particularly when block technique, local anesthetic volume, or patient anatomy differ. Moreover, combining blocks (for example, ISB with selective superior-trunk targeting or other modifications) has been proposed as a strategy to balance surgical anesthesia and respiratory safety, but comparative prospective data examining the effect of ISB alone versus ISB combined with STB on diaphragmatic function are limited. This uncertainty is important because even partial diaphragmatic paresis can degrade postoperative pulmonary mechanics and increase complications in vulnerable patients.

Conditions

Diaphragm Issues

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: DIAGNOSTIC
• Blinding Strategy: TRIPLE

Study Groups

Interscalene block alone

Interscalene block alone, we will inject 20 mL of 0.5 % bupivacaine plus 10 mL of 0.9 % normal saline around brachial plexus in the interscalene site under ultrasonograhy.

Group Type: ACTIVE_COMPARATOR

Regional anesthesia in shoulder surgery

Intervention Type: OTHER

Comparison of the interscalene block alone versus combined with superior truncus block during shoulder surgery in diaphragmatic function

Interscalene block plus Superior truncus block

1. We will inject 7 mL of 0.5 % bupivacaine plus 3 mL of 0.9 % normal saline ( Total amount 10 ml) around brachial plexus in the interscalene site under ultrasonograhy.

2. Also we will inject 13 mL of 0.5 % bupivacaine plus 7 mL of 0.9 % normal saline ( Total amount 20 ml) around Superior trunk of brachial plexus under ultrasonagraphy.

Group Type: ACTIVE_COMPARATOR

Regional anesthesia in shoulder surgery

Intervention Type: OTHER

Comparison of the interscalene block alone versus combined with superior truncus block during shoulder surgery in diaphragmatic function

Interventions

Regional anesthesia in shoulder surgery

Comparison of the interscalene block alone versus combined with superior truncus block during shoulder surgery in diaphragmatic function

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• ASA (American Society of Anesthesiologists) I, II physical status.
• Aged between 20 and 65 years.
• Male or female.
• Body Mass index (BMI): 18-30 kg/m3.
• Scheduled for shoulder surgery.

Exclusion Criteria

• Allergy to local anesthetics.
• Infection at the injection site.
• Coagulation disorders.
• Respiratory diseases ( Acute or Chronic) or Chest trauma.
• Multiple traumatized patients.
• Phrenic nerve injury
• Heart failure, Cardiomyopathy.
• Severe organ dysfunction
• Patient refusal

• Minimum Eligible Age: 20 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: Yes

Sponsors

Sohag University

OTHER

Sponsor Role: lead

Responsible Party

Sherif Salah Ismail

Assistant lecturer of Anesthesia and ICU and Pain Management of Sohag University hospital

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Sherif Salah Ismail Assistant lecturer of Anesthesia

Role: PRINCIPAL_INVESTIGATOR

Assistant lecturer of Anesthesia and ICU and Pain Management of Sohag University hospitals

Central Contacts

Sherif Salah Ismail Assistant lecturer of Anesthesia

Role: CONTACT

sherifsalah383@gmail.com

01007272718

El hadad Ali Mosa Professor of Anesthesia

Role: CONTACT

01019816967

Other Identifiers

Soh-Med--25-11-5MD

Identifier Type: -

Identifier Source: org_study_id