Distance for Interscalene Block

What is the Maximal Effective Distance for Interscalene Block?

Patients experience significant postoperative pain following shoulder surgery, Single shot interscalene block is used in ambulatory shoulder surgery for its advantages that include significant reduction in acute pain and analgesic requirements, prolonged time to first analgesic request, decreased incidence of nausea, as well as earlier hospital discharge.The process of nerve block requires several needle passes, with each of them being at risk of causing nerve injury either by direct trauma or intraneural injection even with the use of the ultrasound. These facts raised concerns and several authors stated that maybe the anesthesiologists should be more careful, keep a safe distance from the nerve, and inject the local anesthetics into fascial planes containing the nerve and not attempt to place the needle in close proximity to the nerve. This study is designed to determine the maximal effective distance away from the nerve for the injection to be effective.

Study Overview

• Status: Completed
• Conditions: Post Operative Analgesia; Regional Anesthesia; Inter Scalene Block

• Study Type: Observational
• Enrollment (Actual): 25

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Toronto, Ontario, Canada, M5T 2S8
      • Toronto Western Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 85 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Patients undergoing shoulder surgery (shoulder arthroscopy or open shoulder surgery)

Description

Inclusion Criteria:

• ASA physical status I-III
• 18-85 years of age, inclusive
• surgery less than 3 hours

Exclusion Criteria:

• contraindications to brachial plexus block (e.g., allergy to local anesthetics, coagulopathy, malignancy or infection in the area)
• existing neurological deficit in the area to be blocked
• pregnancy
• history of neck surgery or radiotherapy
• severe respiratory disease
• inability to understand the informed consent and demands of the study

Study Plan

How is the study designed?

Design Details

• Observational Models: Other
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Success of the inter-scalene block at 20 minutes after injection at a specific distance of the needle tip from the outer sheeth of the nerve	20 mins

Secondary Outcome Measures

Outcome Measure	Time Frame
The onset time of sensory and motor block	the block success will be assessed for each patient every 5 min for 20 mins in the block room beginning when the needle exits the skin
The proportion of inadequate and failed blocks.	the block success will be assessed for each patient every 5 min for 20 mins in the block room beginning when the needle exits the skin
The duration of block, defined as the time from the completion of block performance to the time of the request for the first postoperative analgesic.	during the first 24 hours post operative
The amount of pain and level of satisfaction,	every 30 minutes starting at post anesthesia care unit admission till 120 minutes
The presence of a Claude-Bernard-Horner Syndrome	up to 24 hours post operative
The presence of hoarseness.	up to 24 hours post operative
The presence of other complications such as hematoma, infection, pneumothorax.	up to 24 hours post operative and 7 days post op

Collaborators and Investigators

• Sponsor: University Health Network, Toronto
• Investigators: Principal Investigator: Richard Brull, MD, FRCPC, University of Toronto

Study record dates

Study Major Dates

• Study Start (Actual): February 1, 2012
• Primary Completion (Actual): January 24, 2013
• Study Completion (Actual): March 26, 2014

Study Registration Dates

• First Submitted: March 6, 2012
• First Submitted That Met QC Criteria: March 30, 2012
• First Posted (Estimate): April 2, 2012

Study Record Updates

• Last Update Posted (Actual): January 10, 2018
• Last Update Submitted That Met QC Criteria: January 8, 2018
• Last Verified: January 1, 2018

More Information

Terms related to this study

• Keywords: Regional Anesthesia; Inter-scalene Block; shoulder surgeries
• Other Study ID Numbers: 11-0806-A