Case 42 - typanomastoidectomy Flashcards
1
Q
why is typanomastoidectomy performed?
A
- eustachian tube malfunctions, vacuum created in middle ear
- vacuum assoc with chronic upper resp infections
-
cholesteatoma - abnormal growth of primarily skin cells
- grows behind a perf tympanic membrane (perf due to recurrent infections)
- cholesteatoma assoc with progressive hearing loss, facial nerve damage
- Typanomastoidectomy - remove cholesteatoma and infected bone of middle ear
2
Q
any preop considerations assoc with tympanomastoidectomy?
A
- pts usually manfiest middle ear diseaes: nystagmus, vertigo, n/v
- PONV is important issue to address in these pts
- combo therapy is effective
3
Q
What are the intraop requirements for tympanomastoidectomy?
A
1) surgical anatomy is small, need mangnifying scope
* cruicial to minimize introp bleeding to allow surgical view under scope
2) injury to facial nerve
- facial nerve electromyography may be used
- avoid NMBDs
3) patient position 90 to 180 degree away from anesthesiologist
- long extension circuits
- neck not hyperextended
- eye and ear free of pressure
4
Q
Is nitrous oxide contraindicated during tympanomastoidectomy?
A
Best to avoid nitrous oxide for two reasons:
1) expansion of middle ear air space
- nitrous oxide is more soluble in blood than nitrogen. nitrous oxide will enter middle ear space quicker than nitrogen can diffuse into blood –> expansion of air space.
- typanic membrane graft can be dislodged
2) PONV
5
Q
A