Clinical trial NCT01258959: Anaesthesia for Ophthalmic Surgery: How "Retro" is the Peribulbar Block?
Official title: Anaesthesia for Ophthalmic Surgery: How "Retro" is the Peribulbar Block?
Study type: OBSERVATIONAL
Overall status: COMPLETED
Conditions: Ophthalmic Surgery
Parabulbar Block
Keywords: Ultrasound, retrobulbar, parabulbar, ophthalmic surgery.
Lead sponsor: Sunnybrook Health Sciences Centre
Sponsor class: OTHER
First posted: 2010-12-13
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: PROBABILITY_SAMPLE
Study population: 100 consecutive 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.

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.


Eligibility criteria: 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.

Primary outcomes:
measure: Incidence of detectable retrobulbar spread of local anaesthetics during peribulbar injection.
timeFrame: At start (During peribulbar injection)
Secondary outcomes:
measure: Assessment of block quality
timeFrame: 20 Minutes after block
Other outcomes:
Locations:
city: Toronto
country: Canada
facility: Sunnybrook Health Science Centres
state: Ontario
Study officials:
References:
citation: Luyet C, Eichenberger U, Moriggl B, Remonda L, Greif R. Real-time visualization of ultrasound-guided retrobulbar blockade: an imaging study. Br J Anaesth. 2008 Dec;101(6):855-9. doi: 10.1093/bja/aen293. Epub 2008 Oct 23.
citation: Ripart J, Lefrant JY, de La Coussaye JE, Prat-Pradal D, Vivien B, Eledjam JJ. Peribulbar versus retrobulbar anesthesia for ophthalmic surgery: an anatomical comparison of extraconal and intraconal injections. Anesthesiology. 2001 Jan;94(1):56-62. doi: 10.1097/00000542-200101000-00013.
citation: Ropo A, Nikki P, Ruusuvaara P, Kivisaari L. Comparison of retrobulbar and periocular injections of lignocaine by computerised tomography. Br J Ophthalmol. 1991 Jul;75(7):417-20. doi: 10.1136/bjo.75.7.417.