Friday, April 14, 2006

Pressure-equalizing earplugs do not prevent barotrauma on descent from 8000 ft cabin altitude.



We get repeated queries about the use of vented ear plugs for the relief and prevention of middle ear barotrauma.(Doc's Proplugs, Earplanes, JetEar). Although there is no conceivable reason why they should work across an intact tympanic membrane - there are many who swear by it's benefits. I have often thought that this is more of a placebo effect than anything else and have not promoted or recommended them as beneficial. Now, I have some experimental work and observations to back up my position. In the Aviation, Space and Environmental Medicine Journal, there is report of a good study showing no benefit from the use of JetEar plugs in preventing middle ear barotrauma. As a matter of fact, the ears using the plugs were worse. The abstract of the article is shown below. Whether od not this ear plug translates to the Doc's Proplugs is not known for sure but is highly likely.

Pressure-equalizing earplugs do not prevent barotrauma on descent from 8000 ft cabin altitude.
Klokker M, Vesterhauge S, Jansen EC.
Aviat Space Environ Med. 2005 Nov;76(11):1079-82.

Aviation Medical Center & Dept. of Otorhinolaryngology, Head & Neck Surgery, Rigshospitalet, Copenhagen University Hospital, Blegdamsvej 9, DK-2100 Copenhagen, Denmark. klokker@dadlnet.dk

INTRODUCTION: The aim of this study was to evaluate the effect of pressure-equalizing earplugs available in major airports and drugstores. No previous study has focused on preventing barotrauma using these earplugs. METHODS: Blinded and double-blinded, one type of pressure-equalizing earplugs (JetEars) was studied in 27 volunteers disposed to ear barotrauma. They acted as their own controls with an active earplug in one ear and a placebo earplug in the other ear at random. All were exposed to the same well-defined pressure profile for 1 h at 8000 ft, comparable to the environment in civil commercial air travel in a pressurized cabin. Satisfaction was assessed by questionnaire and objective results were evaluated prior to and after the pressure exposure by tympanometry and otoscopy using the Teed classification. RESULTS: The majority of the volunteers (78%) reported a pleasant noise-reducing feeling using the earplugs. However, 75% also experienced ear pain during descent. In comparing the middle ear pressure before and after pressurization, a decrease was found in ears with both active earplugs and placebo earplugs. No difference between the active and the placebo earplugs were found. Furthermore, after evaluation of the two groups of ears using otoscopy, no prevention of barotrauma was found. In fact, the ears using an active pressure-equalizing earplug scored significantly worse (p = 0.033). CONCLUSIONS: Feelings of noise reduction were reported, but no prevention of barotrauma could be demonstrated with the use of pressure-equalizing earplugs. Pressure-equalizing earplugs cannot be recommended in air travel for preventing ear barotrauma.

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