Ophthalmic Surgery, Parabulbar Block
Conditions
Keywords
Ultrasound, retrobulbar, parabulbar, ophthalmic surgery.
Brief summary
Ophthalmic surgery on the posterior section of the eye can either be performed under general anaesthesia or under local aneasthesia. The local anaesthesia is performed by injecting local anaesthetics behind the eye. There are two techniques: Either the needle is placed into the muscle cone formed by the four recti muscles - this is called intraconal or retrobulbar block, or the needle is placed outside of the muscle cone - this would be called extraconal or peribulbar. In our hospital the investigators usually perform the peribulbar block since it is easier to perform and has a smaller risk to injure the eye. The investigators however realize that the parabulbar block is sometimes very efficient and sometimes not, thus requiring a second or third injection. Now investigators are able to visualize where the local anaesthetics spreads with the help of ultrasound imaging. The aim of the study is to observe and to describe the incidence of intraconal spread of local anaesthetics when a peribulbar block is performed.
Interventions
PROCEDUREUltrasound detection of local anesthetics spread
During the parabulbar injection the ultrasound operator experienced in ultrasound guided retrobulbar block will assess whether there is spread of local anaesthetic in the central cone just behind the sclera (yes or no). The anaesthesist performing the block will be blinded to the ultrasound visualized spread of local anaesthetic.
Sponsors
Sunnybrook Health Sciences Centre
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
-informed consent
Exclusion criteria
* coagulation disorder * INR over 1.5 and/or a platelet count less than 75 X 109/L, * pathological myopia, * inability of the patient to lie down for the operation for more than 2 hours * lack of informed consent.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Incidence of detectable retrobulbar spread of local anaesthetics during peribulbar injection. | At start (During peribulbar injection) | The outcome measure is the description of the spread of local anesthetics during the injection of the drug via the parabulbar needle. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Assessment of block quality | 20 Minutes after block | Assessment of the block quality by ophthalmic surgeon just before surgery starts and at least 20 minutes after the block: complete akinesia and anaesthesia or partial akinesia/anaesthesia. |
Countries
Canada
Outcome results
None listed