Tymps and ARTs Flashcards
what is tympanomentery?
-quick +objective test which assess the state of the middle ear, e.g. tympanic membrane middle ear cavity and ossicles
who is it used for?
-conductive/mixed losses
-paediatrics
-complex patients`
what equipment do we need for tymps?
-tympanometer
-tymp tips
-otoscope
-cavity
-speculea
how do you calibrate the tympanometer?
- check end of the probe for blockages
-use the calibration to make sure the ECV is normal. the trace should be flat
0.5 (no tolerance)
2.0 (5% tolerance)
-Perform a tymp on a known subject if safe to do so. This checks the pump is working properly
what do you do after calibration?
clean everything you have used on yourself and document that the tymp has been calibrated
contraindications for tymps and ARTs
the usual 5 with surgery being especially stapedectomy
-too much wax
-foreign bodies
-swollen
-collapsed ear canal
-very retracted for bulging TM
special care consideration for tymps and ARTs
- can be used for grommets in situ to check tube is clear
- can diagnose a preformation (even healed)
-hyperacusis, noise exacerbated tinnitus and phonophobia
tymp and art patient instructions patient instructions
“This test consists of two parts. First I will insert a soft tip into the opening of your ear canal. You will feel a slight pressure in your ear for a few seconds while I measure the function of your middle ear. You may hear a sound but you do not need to respond or tell me about it. The second part will then begin, which involves playing short, loud sounds. These may take you by surprise when they first begin, and they may get quite loud. You do not need to do anything other than sitting still and remaining quiet. Should you find any of this procedure uncomfortable, or the sounds too loud, please say “stop” or raise your hand”.
-it is important that you dont speak swallow talk
any questions
how do you do tymps?
start on better ear
-otoscopy - pick probe size (check for contraindications)
-instruct the pateint and insert probe and do a quarter turn
-start sweep
-once trace is finished(equal side tail) stop
-do arts
-otoscopy
how do tymps work?
- Probe produces pressure and sound.
- Probe measures what sound is admitted and what is reflected
- It compares pressure either side of the tympanic membrane
- It measures ear canal volume
what should happen in tymps (theory)?
- equal pressure on either side of TM if all middle ear structures (especially the Eustachian tube) are functionally correctly
- sound from theSound from the probe should be admitted (and travel through the middle ear system) and none (or very little) should be reflected back into the ear canal.
- Movement of the middle ear system (compliance - measured in ml*) should be detected.
normal tymp values
pressure = +50 to -50daPa
compliance = 0.3 to 1.6 ml
ECV = 0.6 to 2.5 cm3
how would we explain perforation?
Perforation- The test we have just done shows your ear canal volume is larger than we woud expect which could indicate a hole in your ear drum.
how would we explain otitis media?
Otitis media The test we have just done shows that your ear drum is not moving as we would expect it to which could indicate an infection in your middle ear
how would we explain otosclerosis?
Otosclerosis- The test we have just done shows your ear drum is not moving as much as we expect it too, this could indicate a problem in your middle ear
how would you explain ossicular discontinuity?
Ossicular discontinuity- The test we have just done shows your ear drum is moving more than we would expect it to, therefore ENT may want to look at the bones in your middle ear.
how would you explain a grommet?
Grommet- a) The test has shown a large amount of volume in the ear canal, this indicates that the grommet is working well and still in place. b) The test has shown your ear canal volume to be within normal range, this is indicating that the grommet may be blocked.
what probe tone is used for reflexes?
Acoustic reflex assessment usually uses a 226Hz probe tone unless testing neonates in which higher frequency 1000Hz probe tones are used.
what’s the difference between ipsilateral and contralaterl?
Ipsilateral reflex= measured in the same ear as the stimulus (patient/customer will have just a single probe in their ear)
Contralateral reflex= measured in the opposite ear as the stimulus (patient/customer will have a probe in both ears; one presenting and one recording)
where does sound travel in reflexes?
from the stapedius muscle and middle ear to the cochlea up the 8th nerve to the ventral cochlear nucleus (here contralateral would switch ears) to the superior olivary complex and ventral nucleus down the 7th back to the ME and SM
what are you measuring when recording reflex?
-the AR is the contraction of the SM elicited by the presentation of an acoustically loud sound
-when either ear is presented with a loud sound, the SM on both sides contract
-contraction of the stapedius muscle tilts the anterior stapes away from the oval window and stiffens the ossicular chain
- this results in increased impedance which is measured as a small decrease in compliance by the ear canal probe
should you choose contra or ipsi?
ipsi=
Highly susceptible to artefacts
Sensitive to middle ear pathologies
Not affected by disorders of the opposite ear
contra=
More sensitive to disorders involving the crossed reflex pathways (meaning retrocochlear pathology could be missed out if not performing contra)
Not as susceptible to artefacts
More extensive normative data available for contra assessments
who could we perform ARTs on?
which conditions can it detect?
-patients of SNHL (usually one sided) as you can detect a suspected acoustic neuroma
- patients who are unwilling to cooperate with behavioral testing
-suspected non organic losses
- balls palsy
- nerve damage
- facial paralysis
-acoustics neuroma
do we do any traditional calibration for ARTs?
no only tymp calibrations
