Clinical Practice Guideline

for

EUSTACHIAN TUBE DYSFUNCTION and OTITIS MEDIA

Developed for the

Aerospace Medical Association

by their constituent organization

American Society of Aerospace Medicine Specialists

 

Overview: Eustachian tube dysfunction (ETD), which is most easily recognized as difficulty clearing one’s ears, is often the cause for grounding of airmen.  While most occupations require only normal hearing, a normal otoscopic exam, and absence of an ear disease history, the requirements for flight duty are far more rigorous.  Sudden changes in atmospheric pressure, as are experienced by aviators, demand tubal equilibrating capacity to be in optimal working order.  Failure to equilibrate to rapid changes in atmospheric pressure can lead to the sudden onset of “ear block” – (barotrauma resulting in severe ear pain due to the inability to equilibrate pressures in the middle ear).  This sudden onset of severe pain may be incapacitating and pose great risk to safety of flight.

 

Our knowledge and understanding of the functions and diseases of the eustachian tubes (ET) are due to the pioneering works of men such as Bartolomeus Eustachius (16th century anatomist), Antonio Valsalva (18th century anatomist), and Adam Politzer (19th century otologist).  As an outgrowth of their endeavors, we now realize that the ET serves three physiologic functions: 1) pressure regulation, 2) protection of the middle ear from pathogens/foreign material in the nasopharynx, and 3) clearance of the middle ear space.  Failure of the tubal mechanism can disrupt any and/or all of these functions.  This altered tubal function may then lead to a multitude of complications which vary from mild and transient (i.e. causing temporary grounding) to severe and debilitating (i.e. permanently disqualifying).  For example, the transient difficulty clearing ears caused by viral upper respiratory tract infections (URIs) and/or seasonal allergic rhinitis (SAR) may only cause mild and/or fleeting symptoms.  However, ETD has also been linked to the development of chronic otitis media and secondary cholesteatoma (trapping of squamous debris in the middle ear and mastoid).

 

In its resting state, the ET remains closed and only opens when necessary to equalize pressure.  In flight, ascent usually causes little trouble even in the absence of any active ear clearing maneuvers.  This is due to the passive escape from the middle ear of expanding air as it exceeds the opening pressure of the ET.  However, 10-17% of airmen have reported vertigo during ascent which is believed to be secondary to asymmetry between the right and left side (i.e. alternobaric vertigo-causing a differential input to the vestibular system).  This is more frequently seen on descent which requires the active passage of air into the middle ear space.  This is normally accomplished by the tubal musculature associated with deglutition and/or jaw movements.  The most well known example of this is the Toynbee’s maneuver: displacement of air by the movement of the eardrum when swallowing with the nose closed.  Should such maneuvers fail, air can be forced into the middle ear by increasing nasopharyngeal pressures via the Valsalva maneuver: displacement of air by the movement of the eardrum caused by forceful expiration against a closed nose.  Many authorities suggest as safer alternatives the Toynbee or Frenzel maneuvers: open the jaw, fill mouth with air, pinch the nose, purse the lips, and then close the jaw while displacing air posteriorly by pushing the tongue up and back.  In a minority of cases, anatomic, hormonal, and disease factors cause the ET to be remain open continuously (i.e. a patulous ET).  This often leads to auditory complaints including autophony (hearing one’s own breathing).

 

There are myriad etiologies of ETD and not all are understood in their entirety.  Many mechanisms are easily understood.  For example, the initiation of swelling, inflammation and/or drainage within the ET caused by entities such as viral URI, chronic sinusitis, and/or allergic rhinitis is a rather straightforward cause.  Further, obstructive mechanisms such as adenoid hypertrophy, deviated nasal septum, or nasal polyposis are also well known.  Less well appreciated, however, are other causes of ETD such as the decreased tubal function associated with tobacco smoke (decreased ciliary function), reflux disease (nasopharyngeal exposure to gastric contents), and congenital abnormalities (location/angle of tube, cleft palate, reduced mastoid air cell system).

 

Any history of fullness or clogging of the ears, otalgia, hearing loss, tinnitus or dizziness should prompt an evaluation for ETD.  A common complaint is that no amount of yawning, swallowing, chewing or attempted Valsalva maneuver alleviates the symptoms.  Several methods are available to assess the function of the ET in the office.  Otoscopic observation of tympanic membrane (TM) mobility caused by the Toynbee, Frenzel, Valsalva maneuvers and/or pneumatic otoscopy is good evidence of a functional/patent ET.  Likewise, a normal tympanogram attests to the normal transmission of energy through the middle ear space.  However, studies have not shown good correlation between a normal tympanogram and any predictive value for barotrauma.  The limiting factor for all of these assessment tools; however, is that none of them assess ET function during the dynamic changes in atmospheric pressure experienced by aviators.  Such complex function should be tested during simulated flights in a pressure chamber.  Even this assessment, however, short of expensive and invasive pressure manometer placement, is dependent upon the subjective report of the aviator.  Seeking the best combination of cost, non-invasiveness and accurate surrogacy for the dynamic flight environment has led the United States Air Force to select demonstration of a normal Valsalva maneuver and successful completion of a pressure chamber flight as criteria for pilot selection and training.  The main predictors of barotrauma continue to be a previous history of nasal or otologic disease and/or abnormal otoscopy.

 

Review of the medical literature reveals no clear consensus on the efficacy of treatment modalities for ETD.  While there are studies showing promising results from treating inflammatory, congestive and allergic causes for ETD with the appropriate oral/topical decongestant, antihistamine or nasal steroid, there are also studies which do not duplicate such promising outcomes.  Likewise, success rates following surgical correction for ETD have varied.  Insertion of pressure equalization tubes (PET) has long been the mainstay of surgical treatment for ETD.  However, several investigators have found that while the pressure differential between the middle ear and the external auditory canal may be immediately resolved, the function of the ET itself does not change following PET insertion.  Other procedures such as adenoid resection and laser eustachian tuboplasty have also shown a mix of success and failure in treating ETD.  Thus, regardless of whether medically or surgically treated, and regardless of specific etiology, the outcome of any treatment for ETD needs to be evaluated on a case by case basis to determine the presence of acceptable ET function.  This is especially true in the aviator population.

 

ETD and otitis media (OM), another common disorder of the middle ear, are closely related.  Historically, the pathophysiology of OM has always been linked with abnormalities of ET function.  As previously reviewed, the ET performs the three classic functions of aeration, clearance, and protection of the middle ear.  Traditional teaching has held that the ET function of aeration was limited and that this was the underlying cause of most acute otitis media (AOM).  More recent investigation, however, has suggested that AOM is the result of bacterial entry into the middle ear (i.e., failure of protection).  In either case, that there is a relationship between ETD and the development of OM is clear.  Whether or not ETD precedes AOM, the finding of ETD in patients with AOM is nearly universal.  While space here does not permit a separate treatise on OM and its many variants, the following five principles derived cooperatively by the Centers for Disease Control and the American Academy of Pediatrics should help to guide OM-related diagnosis and treatment decisions: 1) the diagnosis of OM should not be made unless fluid is present in the middle ear, 2) OM should be classified as AOM or otitis media with effusion (OME) on the basis of the presence or absence of signs and symptoms of acute illness, 3) in contrast to AOM, OME should not be treated with an antibiotic, 4) effusion is likely to persist after the treatment of AOM and does not require repeated treatment, and 5) antibiotic prophylaxis for AOM should be used only in accordance with strict criteria.

 

Aeromedical Concerns: ETD may result in the failure to equilibrate middle ear pressures and lead to pain, impairment of hearing, and vertigo, with or without rupture of the tympanic membrane, resulting in compromised aircraft safety if a member of the crew is incapacitated in this way.  ETD may only be minimally symptomatic at ground level.  However, such tubal dysfunction can block the flow of air in and out of the middle ear space.  In the presence of ETD, dynamic perturbations of atmospheric pressure may result in acute barotrauma, resulting in sudden, incapacitating pain.  Should such an event occur immediately prior to or during landing procedures, it could lead to sudden incapacitation and an aircraft mishap.  Treatment should consist of returning to altitude to allow slower equilibration of the middle ear, the use of Afrin, and if the block persists on landing, the use of a Politzer bag to assist in ventilating the middle ear.  There is no quick test to ensure the ET is patent prior to flight; but, being able to Valsalva and prior successful completion of altitude chamber training are a close approximation.  Further, any middle ear disturbance (e.g. ETD or OM) raises concern for decreased and/or loss of hearing, disequilibrium, and the development of more extensive disease.

 

There are some concerns about the chronic use of PE tubes in aviators.  Most patients requiring prolonged PE tubes will end up with a large central perforation which tends to remain as long as the ear is not being ventilated.  Also, the PE tubes can fail.  They get plugged, extrude, cause granulation tissue which then causes bleeding and infection, and can cause perforations of the TM.  They can also act as a conduit for fluids getting in the middle ear especially soapy fluids with low surface tensions that then can cause a chemical irritation of the middle ear and subsequent otorrhea/infection.  The other challenge is that it sometimes takes a microscope to see what is actually going on with a PE tube, so a deployed FS looking at with an otoscope may not be able to discern what is happening with the tube or TM.

 

Medical Work-up: Necessary elements of the medical evaluation include a history of the symptoms while flying and at ground level, the duration of symptoms and all treatments.  The exam needs to focus on the ENT elements to include demonstration of the Valsalva maneuver.  Audiology evaluation with impedance test reports as well as an ENT consultation report to include any surgical notes is also required.  Finally, if there is an operational necessity for an altitude chamber flight, this data is also required in the evaluation.

 

Aeromedical Disposition:

Air Force: Acute ETD/OM secondary to a transient illness (e.g. viral URI or SAR) requires no waiver but is grounding for flyers until resolution.  However, chronic ETD/OM is disqualifying and requires a waiver for FC I/IA, II and III.  Also any surgical procedure for correction of ETD/OM is disqualifying for FC I/IA, II and III.  It is summarily accurate to emphasize that resolution of ETD/OM and adequacy of ET function are to be assessed on a case by case basis and that no one treatment or procedure, per se, will lead to waiver approval.  Regardless of cause or treatment modality, ET functionality must be demonstrable for waiver authority consideration to be granted.  In general, the permanent use of PE tubes in flyers is not a good idea, but it is a fact that adults tend to tolerate chronic use of PE tubes better than children.  What is important is the operational necessity of using the tubes and the clinical judgment of the flight surgeon and treating otolaryngologist.

 

Army: Either of these condition in their acute form are not disqualifying, though require a temporary grounding for the duration of the illness.  However; a history of chronic or recurrent Eustachian tube dysfunction or otitis media is disqualifying for Army aviation service and requires a thorough otolaryngology evaluation for waiver consideration.

 

Navy: A functional Valsalva is required for flying status, and acute ETD/OM is temporarily grounding.  Once resolved, a waiver is generally not required. The Naval Aerospace Medical Institute (NAMI) has not published formal waiver guidance for chronic ETD/OM, and aeromedical disposition of aircrew members suffering from recurrent or chronic ETD/OM will be considered on a case-by-case basis.  Submission of formal ENT evaluation and aeromedical summary will be required at a minimum; consultation with NAMI ENT prior to waiver request submission is recommended.

 

Civilian: The FAA does not consider this medical condition any differently that the military.  The granting of medical certification depends on the individual airman’s ability to clear their ears especially at the time of their medical examination.  Each airman is expected to “self-certify” each time they fly and are taught that they should not fly if they are unable to clear their ears.  Any airman who has such a situation and ends up obtaining medical certification has a condition where they are able to clear their ears. 

 

Waiver Experience:

Air Force: A review of AIMWTS showed 99 cases with the diagnosis of ETD; 3 were FC I/IA, 28 FC II, and 68 FC III.  Of the 69 (69%) disqualified cases, 2 were FC I/IA, 13 were FC II and 54 were FC III.  In every case, except one (optic drusen), the disqualifying diagnosis was the ETD/inadequate or absent Valsalva.  In almost every case where the ETD was treated with aeromedically waiverable medications and/or surgical correction (e.g. PET, adenoidectomy, cholesteatoma resection, nasal polypectomy, etc.), the waiver was granted in the presence of subsequently demonstrated pressure equalization (e.g. altitude chamber).  In only one case was a granted waiver subsequently denied due to recurrent ETD.  Of note, a difference of opinion is noted in review of this group of waivers: 15 of 20 times that waiver was sought for ETD post correction with PETs, waiver was granted; 5/20 times the waiver authority denied waiver for either “permanent need for PETs” or “risk of in-flight PET failure” despite demonstrated placement and function of the PETs. (Of historical note, in WWII, healthy German Stuka Dive bomber pilots had myringotomies done to facilitate rapid pressure changes on bombing runs).  However if a pilot has a clinical problem, PE tubes solve the immediate issue of middle ear ventilation, but long term challenges are the following: 1) occlusion of the PE tube from wax or serous fluid, 2) premature extrusion, 3) contamination of the middle ear with water-especially soapy water with secondary otitis media or chemical inflammation, 4) risk of cholesteatoma, 5) persistent TM perforation, 6) potential for unequal middle ear equilibration leading to alternobaric vertigo, and 7) inability to care for these problems in an austere environment.

 

For OM, AIMWTS review showed 9 cases with the diagnosis of OM (1 duplicate case from the ETD group).  All 9 submissions were for FC III aviators.  In every case, the OM waiver was granted whether the end result was resolution, treatment with aeromedically waiverable medications, and/or surgical correction (e.g. PETs).  Two of these waivers were later denied because of a comorbid diagnosis (Crohn’s disease and complications status post cholesteatoma resection requiring ossicle reconstruction).

 

Army: The Aeromedical Epidemiological Data Repository (AEDR) catalogs all Army flight physicals since 1960.  There have been approximately 160,000 individual aircrew entered in this database.  During this period of time, there were 33 aeromedical summaries requesting waiver in the pilot population (14 rated and 19 initial pilot applicants) of these, 7 rated pilots and 3 applicants were waivered.  During this period 14 requests for waiver among non-rated aircrew were received and five waivers were granted.

 

Navy: Not available at this time.

 

Civilian: See above.

 

ICD9 Codes for Eustachian Tube Dysfunction and Otitis Media

381.0

Acute nonsuppurative otitis media

381.01

Acute serous otitis media

381.1

Chronic serous otitis media

381.02

Acute mucoid otitis media

381.2

Chronic mucoid otitis media

381.3

Other and unspecified chronic nonsuppurative otitis media

381.4

Nonsuppurative otitis media, not specified as acute or chronic

381.5

Eustachian salpingitis

381.6

Obstruction of the Eustachian tube

381.7

Patulous Eustachian tube

381.8

Other disorders of the Eustachian tube

381.9

Unspecified Eustachian tube disorder

382.0

Acute suppurative otitis media

382.01

Acute suppurative otitis media with spontaneous rupture of the ear drum

382.3

Unspecified chronic suppurative otitis media

382.4

Unspecified suppurative otitis media

382.9

Unspecified otitis media

 

 

References:

 

Groth P, Ivarsson A, Nettmark A, Tjernstrom O.  Eustachian tube function in selection of airmen.  Aviat Space Environ Med, 1980; 51:11-17.

 

Rainford DJ and Gradwell DP.  Ernsting’s Aviation Medicine, 4th Edition.  Published by Hodder Arnold.  2006: pp. 717-725.

 

Seibert JW, and Danner CJ.  Eustachian tube function and the middle ear.   Otolaryngol Clin N Am, 2006; 39:1221-1235.

 

Davis JR, Johnson R, Stepanek J, Fogarty J.  Fundamentals of Aerospace Medicine, 4th Edition.  Published by Lippincott Williams and Wilkins.  2008: pp. 380-391.

 

Swarts JD and Bluestone CD.  Eustachian tube function in older children and adults with persistent otitis media.  International Journal of Pediatric Otorhinolaryngology. 2003; 67:853-859.

 

Cantekin EI, Bluestone CD, Rockette HE, et al.  Effect of decongestant with or without antihistamine on eustachian tube function.  Ann Otol Rhinol Laryngol Suppl, 1980; 89(3 Pt 2):290-5.

 

Tracy JM, Demain JG, Hoffman KM, et al.  Intranasal beclamethasone as an adjunct to treatment of chronic middle ear effusion.  Ann Allergy Asthma Immunol, 1998; 80(2):198-206.

 

van Heerbeek N, Ingels KJ, Zielhaus GA.  No effect of a nasal decongestant on eustachian tube ventilator function in children with ventilation tubes.  Laryngoscope, 2002; 112(6):1115-8.

 

Hendley JO. Otitis media. N Engl J Med, 2002; 347(15): 1169-1174.

 

Inglis AF and Gates GA.  Acute Otitis Media and Otitis Media with Effusion.  Ch. 200 in Cummings: Otolaryngology: Head & Neck Surgery, 4th ed., 2005.  Published by Mosby, Inc.

 

 

 

Prepared by Drs. Duncan Hughes and Dan Van Syoc

 

November 14, 2011