How do I perform a Eustachian tube function test?
On the GSI TympStar Pro, you can perform the Eustachian tube function whether the eardrum is intact or perforated. To perform the Eustachian tube function intact test, what you do is a series of three tympanograms. You are manually adjusting the middle ear pressure to make sure that the Eustachian tube is opening and closing. Place the probe into the ear and go to the intact Eustachian tube function tests, and press Start. The first thing that you do is just a regular tympanogram. When that's completed, hold the pressure out at +400 decapascals and have the patient drink some water. By doing that, the Eustachian tube, if functioning properly, should open and close changing the pressure. When your patient is done swallowing, press Continue and do a second tympanogram. Hopefully there's a little shift there. When the second tympanogram is complete, it will hold the pressure at -400 decapascals and have the patient swallow again. This will manually change that middle ear pressure if the Eustachian tube is functioning. When they're done swallowing, press Continue, and perform a third tympanogram with that third condition and pressure. At the end of the test you will interpret based on the shift between the peaks. You are looking for a 15 - 20 decapascals shift between any of the two tympanograms.
Now if the tympanic membrane is perforated, you cannot do a tympanogram. In the Eustachian tube function perforated test, put the probe into the ear increase that pressure to +400 decapascals and hold it. When you get to the peak pressure of +400 decapascals, have the patient swallow. When they swallow, the Eustachian tube should open and close. You'll see the tracing at positive 400. The pressure would drop if the Eustachian tube opens. When it closes, the pressure will stabilize again. Have your patient do that a couple of times to see some sort of stair step result on the screen. If you are going up the positive pressure to positive 400 and suddenly the Eustachian tube does blow open, the pressure will go back down to zero and try again. If it blows open it will continue to go down to zero and keep trying to pressurize. That is a normal response.