Otic barotrauma - Incidence in free-fall paratroopers: An observational study

Military free fall is distinct form of tactical parachuting being performed by paratroopers. During free-fall, the paratrooper descends at speeds more than 193 km/hour i.e. 1000 ft in 6 s from a height of around 10,000-12,000 feet. Human bodies are well adapted to bear small range of atmospheric pressure; however, a wide range of pressure difference resulting from sudden altitude change may lead to significant morbidity in the form of barotrauma in air-filled bodily cavities. Middle ear barotrauma appears as a result of uncorrectable rapid pressure difference between middle ear and the surroundings. This study was undertaken to evaluate the incidence of barotrauma among 30 free-fall paratroopers.

The paratroopers consenting for study after detailed history taking were evaluated on ground in an uncontrolled natural setting with otoendoscopy and tympanometry before and after the free-fall parachute jump. The otoendoscopic findings were classified as per the modified Teed's criteria (O'Neill Grading System) of middle ear barotrauma. Stuarte Maxwell test was used as the primary statistical test and was applied to assess changes in specific parameters, such as otoendoscopic findings and tympanogram curves.

The results across different parameters generally indicated that the observed changes were not statistically significant. The overall change in otoendoscopic findings in both ears was not statistically significant (Stuart-Maxwell test: χ² = 2.000, p = 0.368). The overall change in tympanogram curve (right) was not statistically significant (Stuart-Maxwell test: χ² = 3.000, p = 0.558). The overall change in tympanogram curve (left) was not statistically significant (Stuart-Maxwell test: χ² = 2.000, p = 0.736).

The study aimed to find out barotrauma related to free-fall in trainee paratroopers. We did not find an increased rate of ear symptoms or signs in our study population suggesting that free-fall may not cause any barotrauma. However, a larger cohort may provide a more comprehensive understanding of the prevalence and potential risk factors associated with otic barotrauma in paratroopers. To conclude, our study provides valuable insights into the auditory health of paratroopers during free-fall jumps.