Clinical trial NCT01703130: Determining the Minimal Effective Volume (MEAV95) for Interscalene Brachial Plexus Block for Surgical Anesthesia
Official title: Determining the Minimal Effective Volume (MEAV95) for Interscalene Brachial Plexus Block for Surgical Anesthesia
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: PHASE4
Conditions: Shoulder Pain
Keywords: ISPB
Brachial Plexus Block
Anesthesia
Pain Management
Surgery
Lead sponsor: Sunnybrook Health Sciences Centre
Sponsor class: OTHER
Collaborators: name: The Physicians' Services Incorporated Foundation
First posted: 2012-10-10
Enrollment: 60
Sex: ALL
Minimum age (years): 18
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP
Primary purpose: TREATMENT

Brief summary: Interscalene block (ISB) consistently demonstrates superior pain relief after shoulder surgery. However, patients can experience complications such as blurred vision, hoarseness and shortness of breath with the standard volumes of local anesthetic used in contemporary practice. Patients with respiratory diseases are precluded because of the potential effects on respiration. However, they are then exposed to the risks of general anesthesia and opioid medications which can also have detrimental effects on respiration. Ultrasound guided ISB can reduce the local anesthetic volume required to produce anesthesia for shoulder surgery; this may reduce the complications from ISB to allow patients previously unable to benefit to have this technique, such as patients with obesity and respiratory disease. In order to do so the investigators will use an up-down methodology to find the minimum volume of local anesthetic to provide sufficient anesthesia for shoulder surgery.


Eligibility criteria: Inclusion Criteria:

* Patients undergoing elective arthroscopic shoulder surgery in the sitting position
* Patients aged \>=18 and \<=75 years
* ASA I-III

Exclusion Criteria:

* Patient refusal for surgery under ISBPB with sedation
* Lack of capacity to provide informed consent
* Pre-existing COPD, unstable asthma or diaphragmatic dysfunction
* Coagulopathy
* Infection at injection site
* Allergy to local anesthetics
* Opioid tolerance (\>30mg oral morphine or equivalent/day for \>1 week)
* BMI\>40
* Inability to complete questionnaires and assessments (consent, follow-up phone call) due to language barrier
* Pregnancy or lactation

Primary outcomes:
measure: MEAV95 of ropivacaine 0.75%
timeFrame: 30 minutes post injection
Secondary outcomes:
measure: Motor blockade
timeFrame: 30 minutes
measure: Bedside spirometry
timeFrame: 30 minutes post block, 30min post-surgery, and 2 hours post surgery
measure: Diaphragmatic excursion
timeFrame: 30 minutes post block, and 2 hours post surgery
measure: Complications
timeFrame: 30 minutes
measure: Pain Scores on Visual Analog Scale
timeFrame: at baseline, after surgery at 30 and 60 minutes in the PACU, and at 1 hour intervals until discharge
measure: Total opioid consumption until discharge
timeFrame: 24 hours (at discharge)
measure: Opioid related side effects
timeFrame: 24 hours (at discharge)
measure: Time to first analgesic use
timeFrame: within 24 hours post surgery
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Sunnybrook Health Sciences Centre - Holland Orthopaedic and Arthritic Centre
state: Ontario
Study officials:
affiliation: Sunnybrook Health Sciences Centre
name: Colin McCartney
role: PRINCIPAL_INVESTIGATOR
affiliation: Sunnybrook Health Sciences Centre
name: Stephen Choi
role: STUDY_CHAIR
affiliation: Sunnybrook Health Sciences Centre
name: Jane Wang
role: STUDY_CHAIR
affiliation: Sunnybrook Health Sciences Centre
name: Moein Tavakkoli Zadeh
role: STUDY_CHAIR
References: