Diaphragm Sparing Effect of Subomohyoid Block With Infraclavicular or Subscapularis Blocks in Comparison With Interscalen Block for Postoperative Analgesia in Shoulder Surgeries

The gold standard for shoulder analgesia is the interscalene block (ISB), but it has its own share of disadvantages such as phrenic nerve block, recurrent laryngeal nerve involvement and Horner's syndrome may lead to patient discomfort .Others, such as intrathecal spread and systemic toxicity of local anesthetic, can have serious consequences.

Phrenic nerve injury is a common complication with regional anesthesia. Its either temporary with Transient Phrenic Nerve Palsy leading to hemidiaphragmatic paresis after interscalene block or other injections of local anesthetic in the neck .

Although studies of ISB have shown a reduction in the incidence in hemidiaphragmatic paralysis with low-volume ISB, the risk of phrenic paralysis is not completely eliminated.

To bypass this complication, distal block of the shoulder innervation is recommended such as subomohyoid infraclavicular and subomohyoid subscapularis blocks.

Study Overview

• Status: Completed
• Conditions: Shoulder Surgeries Operations
• Intervention / Treatment: Procedure: diaghragm affection by ultrasound before and after the blocks

Detailed Description

Ultrasound has a significant role in recent anesthesia. It plays a significant role in detecting diaphragmatic mobility and detecting phrenic nerve palsy after regional anesthesia . the common and standard technique for shoulder analgesia is interscalen block. but it has its own complications like phrenic nerve palsy.

to bypass this complications ,several ways had been tried to overcome this complications.

in this study, the investigator compare between the standard interscalen block with distal blocks like infraclavicular subomohyoid block and subomohyoid subscapularis blocks according to diaghragm affection , duration of analgesia , side effects occured with blocks.

For infraclavicular subomohyoid block, the infraclavicular approach targets the posterior and lateral cords, thus anesthetizing the axillary nerve (which supplies the anterior and posterior shoulder joint), whereas the suprascapular nerve block done by blocking subomohyoid muscle anesthetizes the posterior shoulder.

For subscapularis subomohyoid block, subscapularis is done before subomohyoid block. Subscapularis block target subscapular nerve which arise from posterior cord and present on ventral surface of subscapularis muscle .

• Study Type: Interventional
• Enrollment (Actual): 87
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Sharqia Province
    • Zagazig, Sharqia Province, Egypt, 44519
      • Emad Hamdy Mohamed Morsy

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patient acceptance.
• ASA I and ASA II.
• Age 21-60 years old.
• Both gender.
• BMI < 35 Kg/m2.
• Accepted mental state of the patient.
• Elective Unilateral upper limb surgeries at the level of the shoulder.
• Time of surgery less than 2 hours

Exclusion Criteria:

• - Patient refusal.
• Peripheral neuropathy.
• Pathological coagulopathy.
• Infection at the injection site.
• Untreated pneumothorax.
• Disturbed conscious level.
• An allergy to local anesthetics used in this study

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: interscalen group; (29) patients will receive an interscalene block before induction of general anaesthesia. Patients will receive 20 ml of bupivacaine 0.25 %+250 mg of magnesium sulphate.	Procedure: diaghragm affection by ultrasound before and after the blocks; the participant will assess diaphragm sparing in each block and evaluate effectiveness of infraclavicular subomohyoid blocks and subomohyoid subscapularis blocks according to intraoperative and postoperative analgesia and diaphragm affection and comparing them with interscalen and with each others
Active Comparator: subomohyoid infracavicular group; (29) patients will receive subomohyoid infraclavicular block before induction of general anesthesia. Patients will receive 20 ml of bupivacaine 0.25 %+250 mg of magnesium sulphate.	Procedure: diaghragm affection by ultrasound before and after the blocks; the participant will assess diaphragm sparing in each block and evaluate effectiveness of infraclavicular subomohyoid blocks and subomohyoid subscapularis blocks according to intraoperative and postoperative analgesia and diaphragm affection and comparing them with interscalen and with each others
Active Comparator: subomohyoid subscapularis group; (29) patients will receive subomohyoid subscapularis block before induction of general anesthesia. Patients will receive 20 mL of 0.25% bupivacaine + 250 mg of magnesium sulfate.	Procedure: diaghragm affection by ultrasound before and after the blocks; the participant will assess diaphragm sparing in each block and evaluate effectiveness of infraclavicular subomohyoid blocks and subomohyoid subscapularis blocks according to intraoperative and postoperative analgesia and diaphragm affection and comparing them with interscalen and with each others

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change is being assessed (Diaphragm excursion)	As shown before diaphragm excursion will be examined preoperative as basal measurement, immediately postoperative in the PACU and 6 hours postoperatively to detect diaghragm excursion.If ratio of post to pre-block is < 25% this means that phrenic nerve block is included.	basal preoperatively , immediately postoperatively in the pacu and 6 hours postoperatively
Thickness fraction	The percentage change in thickness between end expiration and peak inspiration. It was calculated as follows: (thickness at peak inspiration - thickness at end expiration/thickness at end expiration) ×100.	basal preoperatively, immediately postoperatively in the PACU, and 6 hours postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
postoperative complication of the studied groups	the investigator will record patients with complications from the blocks like hypoxemia with saturation <90% , bradycardia with heart rate <50, nausea and vomiting	24 hours
Visual Analogue Scale (VAS) at different intervals within and between the studied groups	The investigators ask the patient to estimate the degree of pain on a scale from 1 to 10 and ask the patient to report the degree of pain from 0 to 10, with 0 no pain to 10 worst pain.	immediately postoperative in the PACU , 6 hours postoperatively up to 24 hour postoperatively
Total pethidine consumption in 24 hours of the studied groups	The investigator will calculate the total amount of pethidine consumed over a 24-hour period.	24 hours

Collaborators and Investigators

• Sponsor: Zagazig University

Publications and helpful links

General Publications

• Jensen MP, Chen C, Brugger AM. Interpretation of visual analog scale ratings and change scores: a reanalysis of two clinical trials of postoperative pain. J Pain. 2003 Sep;4(7):407-14. doi: 10.1016/s1526-5900(03)00716-8.
• Musso D, Flohr-Madsen S, Meknas K, Wilsgaard T, Ytrebo LM, Klaastad O. A novel combination of peripheral nerve blocks for arthroscopic shoulder surgery. Acta Anaesthesiol Scand. 2017 Oct;61(9):1192-1202. doi: 10.1111/aas.12948. Epub 2017 Aug 4.
• Dhir S, Sondekoppam RV, Sharma R, Ganapathy S, Athwal GS. A Comparison of Combined Suprascapular and Axillary Nerve Blocks to Interscalene Nerve Block for Analgesia in Arthroscopic Shoulder Surgery: An Equivalence Study. Reg Anesth Pain Med. 2016 Sep-Oct;41(5):564-71. doi: 10.1097/AAP.0000000000000436.
• Battaglia PJ, Haun DW, Dooley K, Kettner NW. Sonographic measurement of the normal suprascapular nerve and omohyoid muscle. Man Ther. 2014 Apr;19(2):165-8. doi: 10.1016/j.math.2013.12.005. Epub 2013 Dec 27.
• Bergmann L, Martini S, Kesselmeier M, Armbruster W, Notheisen T, Adamzik M, Eichholz R. Phrenic nerve block caused by interscalene brachial plexus block: breathing effects of different sites of injection. BMC Anesthesiol. 2016 Jul 29;16(1):45. doi: 10.1186/s12871-016-0218-x.
• Panero AJ, Hirahara AM. A Guide to Ultrasound of the Shoulder, Part 2: The Diagnostic Evaluation. Am J Orthop (Belle Mead NJ). 2016 May-Jun;45(4):233-8.
• Boon AJ, O'Gorman C. Ultrasound in the Assessment of Respiration. J Clin Neurophysiol. 2016 Apr;33(2):112-9. doi: 10.1097/WNP.0000000000000240.
• Aszmann OC, Dellon AL, Birely BT, McFarland EG. Innervation of the human shoulder joint and its implications for surgery. Clin Orthop Relat Res. 1996 Sep;(330):202-7. doi: 10.1097/00003086-199609000-00027.

Study record dates

Study Major Dates

• Study Start (Actual): July 20, 2023
• Primary Completion (Actual): December 20, 2023
• Study Completion (Actual): December 30, 2024

Study Registration Dates

• First Submitted: May 14, 2023
• First Submitted That Met QC Criteria: June 16, 2023
• First Posted (Actual): June 27, 2023

Study Record Updates

• Last Update Posted (Estimated): January 2, 2026
• Last Update Submitted That Met QC Criteria: December 26, 2025
• Last Verified: December 1, 2025

More Information

Terms related to this study

• Other Study ID Numbers: #6024/5-4-2022

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: planned after completion of the study
• IPD Sharing Time Frame: after puplication of the study
• IPD Sharing Access Criteria: contact of principal investigator
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP; ICF; CSR

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No