040 Menschliches Leistungsverm.
Barotrauma

010 Luftrecht

030 Flugplanung

040 Menschl. Leistungsverm.

050 Meteo

060 Navigation
080 Aerodynamik

Voice JAR

Voice FAA

US

Miscellaneous

Links

Trommelfell, Druckausgleich und Vertico:

 

Vestibular Systems and Barotrauma

The vestibular system contains the labyrinth, one of the organs that gives us our sense of balance. In cases where one of either vestibular systems (i.e., the right or left) no longer functions because of disease or trauma, our bodies compensate over time. Recovery can appear complete, often with therapy and retraining, to the degree that a balance deficit is imperceptible.

Most people are able to return to their normal activities. However, any damage or injury to the remaining vestibular organ would cause permanent and untreatable balance disturbance, in which even one's ability to walk and activities of basic coordination become affected.

Here's a brief summary of vertigo caused by barotrauma or stimulation (i.e., any irritation or increase in functional activity) to the ears.

Otic barotrauma, which is damage to the middle ear and / or inner ear caused by pressure, presents an inherent risk for scuba divers. In fact, the most commonly reported injuries involve barotrauma to the middle ear. Barotraumatic injury to the inner ear (involving trauma to the cochlea, perilymph fistula of the oval or round window or damage to the vestibular system), while less common, often has permanent aftereffects that can manifest as hearing loss and / or disturbances in balance. Also a rare occurrence, inner ear decompression sickness (DCS) presents similar symptoms but won’t be discussed extensively here.

Vertigo, DCS and Barotrauma

An affected diver can report vertigo, or the sensation of spinning. This in turn can cause nausea and vomiting, a diagnostic dilemma. In the case of inner ear DCS, prompt recompression is the recommended treatment. In the event of inner ear barotrauma, however, recompression is not recommended; the compression in the chamber would aggravate and worsen the trauma.

In the case of vertigo from middle ear barotrauma, the treating physician usually recommends traditional medical treatment of decongestants and, possibly, prophylactic antibiotics.

Why the Vertigo?

Determining the cause of vertigo starts with obtaining a careful history of the dive profile and the evolution of symptoms. Performed by an ENT specialist, this is combined with objective diagnostic testing.

On descent, clearing one’s ears by using the modified Valsalva maneuver may cause uneven pressure in the middle ears and result in vertigo (see a description of various methods of ear equalization on the next page, as well as in the Medical section of the DAN website).

Additionally, divers can experience vertigo with a perforation of either eardrum. Caused by failure to clear properly on descent or by performing a Valsalva maneuver too forcefully, a perforation can cause cold water to penetrate the middle ear. This causes unequal stimulation of the vestibular system and creates the sense of spinning (called caloric stimulation vertigo). In either case, the resulting disorientation can present a risk drowning or rapid ascent if the diver panics.

After experiencing a middle ear barotrauma, the individual who continues to dive may have problems during ascents and descents. The resulting congestion in the middle ear can cause unequal equalization. When uneven pressurization of the middle ear is momentary, the diver may experience the spinning sensation only briefly as his or her ears equalize on ascent. Alternatively, he or she may even reach the surface while still experiencing the spinning sensation. As the middle ear pressure equalizes in both ears, the symptoms tend to disappear.

Instances where the spinning sensation does not resolve spontaneously may indicate the possibility of inner ear barotrauma. If a diver performs a forceful Valsalva maneuver and then experiences vertigo or unsteadiness, inner ear barotrauma is a possibility. This condition is a medical emergency and should be evaluated by a physician as soon as possible.

Don’t Ignore It

The diver who wants to continue to dive safely should carefully consider issues of ear barotrauma: what is often considered a minor nuisance could become a problem if left unchecked. Continuing to dive after minor middle ear barotrauma (e.g., discomfort and minor pain on descent or ascent) can progress to severe and more serious forms of barotrauma. This may affect future diving or even your lifestyle.

When in doubt, get a medical evaluation. You’ll rest easier and be able to keep diving safely with healthy ears.

References

Bové, Alfred A. and Davis, J. (1997) Diving Medicine - 3rd ed. W.B. Saunders.

Edmonds, C., Lowry, C and Pennefather, J. (1992). Diving and Subaquatic Medicine, 3rd ed., Butterworth Heinemann.

About the Author

DAN Medical Information Specialist Celia Evesque, NREMT-I, DMT, has been a dive instructor for 11 years and a DAN Medic for the last two and a half years. She is a former U.S. Army helicopter pilot and a graduate of the University of Florida.

Dr. Shannon E. Hunter of Duke University Medical Center is gratefully acknowledged for her continued assistance.

siehe Links:
http://www.diversalertnetwork.org/medical/articles/article.asp?articleid=58
http://www.bcm.edu/oto/grand/011300.html