Large Animal Anaesthesia Flashcards
What structures does a retrobulbar nerve block desensitise?
The inner structures of the eye.
The optic, oculomotor, abducens, trochlear nerves and the maxillary and ophthalmic branches of the trigeminal
How is a retrobulbar nerve block performed?
Two methods:
- A cured needle is inserted round the back of the eye, where it deposits LA. However, this can bring infection and neoplasia round to the back - not a problem if enucleating.
- Insert a spinal needle through the supraorbital fossa, into the back of the eye where LA is deposited.
What does a supraorbital nerve block desensitise?
The frontal nerve- which innervates the the medial two thirds of the upper eye lid.
Where is a supraorbital nerveblock performed?
The supraorbital canal
What structure does a lacrimal nerve block desensitise
The lacrimal nerve - which innervates the lateral canthus.
How is a lacrimal nerve block performed?
LA is deposited in the lacrimal notch
What does a zygomatic nerve block desensitise?
The zygomatic nerve - which innervates the lower eye lid
How is a zygomatic nerve block performed?
A line block along the ventrolateral orbital rim
What does an infratrochlear nerve block desensitise?
The infratrochlear nerve - which innervates the medial canthus, including the third eye lid.
How is an infratrochlear nerve block performed?
A needle is placed into the trochlear notch on the medial aspect of the dorsal orbital rim.
What structures does an infraorbital nerve block desensitise?
The incisors and premolars directly.
A large volume, however, will travel retrograde through the canal and desensitise the molars and paranasal sinuses.
How is an infraorbital nerve block performed?
The thumb is placed on the rostral facial crest, and the middle finger in the nasal notch. This positions the index finger in the foramen. Place the needle into this foramen and inject.
What structures does a maxillary nerve block desensitise?
The maxillary branch of the trigeminal nerve. This desensitises the premolars and molars.
How is a maxillary nerve block performed?
A needle is placed into the maxillary foramen and a large quantity of LA injected.
What structures does an inferior alveolar nerve block desensitise?
The lower arcade, mandible and lower lips as these are all innervated by the inferior alveolar nerve which is a branch of the mandibular nerve.
What nerve block is being performed in the red area?
supraorbital /frontal nerve block
What nerve block is being performed in the green area?
Lacrimal nerve block
What nerve block is being performed in the blue area?
Zygomatic nerve block
What nerve block is being performed in the orange area?
Infratrochlear nerve block
What nerve block is being performed in this image?
Mental nerve block (mandibular)
What nerve block is being performed in this image?
Inferior alveolar nerve block (mandibular nerve block)
What nerve block is being performed in this image?
Infraorbital nerve block
What nerve block is being performed in this image?
Maxillary nerve block
