Clinical trial NCT02459782: Ultrasound Guided Peribulbar Anaesthesia - A Novel Dual Quadrant Injection Technique
Official title: Ultrasound Guided Peribulbar Anaesthesia: a Real-time Ultrasound Guided Technique With a Novel Dual Quadrant Injection
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Eye Diseases
Keywords: Ultrasound guided peribulbar anesthesia
Lead sponsor: Sunnybrook Health Sciences Centre
Sponsor class: OTHER
First posted: 2015-06-02
Enrollment: 22
Sex: ALL
Minimum age (years): 18
Maximum age (years): 90
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NA
Intervention model: SINGLE_GROUP

Brief summary: Peribulbar anaesthesia for ocular surgery depends on the spread of local anaesthetic throught the orbit to be successful and has a relatively high failure rate. This study will examine a novel ultrasound guided approach to peribulbar anaesthesia which should extend the depostion of local anaesthetic by using a dual quadrant injection technique. The study will assess the feasibility of this technique, how successful it is and whether any obvious safety issues arise with its use.

Detailed description: Peribulbar anesthesia is widely used for anterior and posterior chamber ophthalmic procedures. It is a blind technique which is traditionally carried out by inserting a needle in the infero-lateral aspect of the orbit below the globe and injecting a volume of 8 - 12 mL of local anesthetic in the periorbital space. The goal of this inejction is to achieve akinesia and anesthesia of the eye sufficient for surgery. The technique has a relatively high failure rate of up to 30%. A failure or insufficient block requires a second or rarely a third peribulbar injection to achieve success. Ultrasound can be used to guide needles in the human body and has been successfully used in many anatomic locations for anaesthesia. This study will assess whether ultrasound can guide the block needle in ophthalmic anesthesia to deliver local anesthetic via a single entry into two discrete locations within the periorbital space - the first in the infero-lateral quadrant and the second in the infero-medial quadrant. If this can be done the investigators may achieve a higher success rate for this block with a lower volume potentially improving the quality of the block and its safety.

Eligibility criteria: Inclusion Criteria:

* ASA score less than III and ability to provide a written informed consent
* 22 patients presenting for opthalmic surgery

Exclusion Criteria:

* Coagulation disorder or anticoagulated with INR \> 1.5
* Platelet count \< 75 X 10\*9/L
* Significant Myopia (axial length \> 28mm)
* Patients unable to lie supine for 2 hours
* Patients with recent gas or silicone injections in/around the eye

Primary outcomes:
measure: Block Success
timeFrame: 10 minutes post intervention
Secondary outcomes:
measure: Block Quality (standardized Ocular Scoring System for akinesia and anaesthesia)
timeFrame: 5 and 10 minutes
measure: Block Volume
timeFrame: 1 minute
measure: Duration of Procedure
timeFrame: 1 to 10 minutes
measure: Complications
timeFrame: 6 Weeks
measure: Image Visualization
timeFrame: 1 minute
Other outcomes:
Locations:
Study officials:
affiliation: Sunnybrook Health Sciences Centre
name: Paul G McHardy, MD
role: PRINCIPAL_INVESTIGATOR
References: