Clinical and tympanometric findings in repeated recreational scuba diving

BACKGROUND: Due to the condition known as middle ear squeeze, scuba diving has become one of the main causes of barotrauma, and the acute form of this condition has been relatively well established. However, there are few reports available on clinical or laboratory findings in divers who practise repeated diving. The objective of the present study was to assess the otological effects of repeated dives. METHOD: This was an observational study conducted on 19 recreational scuba divers, considered to be experienced divers according to the criteria established by the Professional Association of Dive Instructors (PADI). These divers undertook four dives per day on five consecutive days, and their tympanic membranes were assessed using tympanometry and otoscopy. Data were analysed using the chi(2)-test for trend. The level of statistical significance was set at p<0.05 in all analyses. RESULTS: The findings suggest that multiple scuba dives over a short period of time cause damage to the structures of the ear, as evidenced by the tympanometric and otoscopic findings, which revealed cumulative effects of pressure against the tympanic membrane and within the middle ear. This condition was not observed when surface intervals exceeded 11h. CONCLUSIONS: The results suggest that extending surface intervals may offer protection against middle ear barotrauma in recreational scuba diving.