Anaesthesia for Ophthalmic Surgery: How "Retro" is the Peribulbar Block?

Sunnybrook Health Sciences Centre

Status: Completed

Conditions: Parabulbar Block; Ophthalmic Surgery

Treatments: Procedure: Ultrasound detection of local anesthetics spread

Study type: Observational

Funder types: Other

Identifiers

NCT01258959

Retro-Parabulbar

Details and patient eligibility

About

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.

Enrollment: 100 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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.

Trial design

100 participants in 1 patient group

Ophthalmic surgery patients

Description:

Patients (men and women) of at least 18 years of age undergoing an ophthalmic procedure on the posterior section of the eye under local anaesthesia, i.e. with a peribulbar block. Inclusion and exclusion criteria for the study are the same as for the peribulbar anaesthesia.

Treatment:

Procedure: Ultrasound detection of local anesthetics spread