Chapter 121: Eye blocks

Question 1

What is the typical local anesthetic agent used for eye blocks? What is added?

Answer 1

2% lidocaine 1:1 with 0.5% bup

Hyaluronidase can be added to shorten the onset time

Question 2

Retrobulbar block is also known as?

Answer 2

Intraconal block

Question 3

What is blocked with a retrobulbar block?

Answer 3

ciliary gangion, ciliary nerves, CN II, III and VI

Question 4

What are some of the complications of retrobulbar block?

Answer 4

Retrobulbar hemorrhage- see motor block of globe, upper eyelid closing, proptosis. May need to cancel surgery

Question 5

What is the peribulbar block also known as?

Answer 5

Exraconal block

Question 6

With peribulbar blocks what risks are deceased as compared to retrobulbar blocks?

Answer 6

intraocular and intradural injection is decreased, decreased risk of retrobulbar hemorrhage and direct optic nerve injurty

Question 7

What nervous system pathway does the oculocardiac reflex go through?

Answer 7

bradicardia, even asytole

Trigeminal-vagal via the ciliary brach of the ophthalmic division of the trigeminal nerve

(may be a result of a block placement or retrobulbar hemorrhage)

Question 8

What can occur with eye blocks that may result in total loss of vision?

Answer 8

central retinal artery occlusion can occur after retrobulbar hemorrhage OR if dura around the optic nerve is penetrated and LA injeted in subarchnoid space

Question 9

What would you suspect if the patient has immediate restlessness and pain after eye block?

Answer 9

puncture of posterior globe- may result in retinal detachment

Question 10

What would you suspect if the patient developed neurologic symptoms such as disorientation, amauroxis fugax, convulsions right after the eye block?

Answer 10

CSF injection