Review Ear Disorders in Scuba Divers MH Azizi Abstract Academy of Medical History of underwater diving dates back to antiquity. Breath-hold technique in diving was Sciences of the IR Iran, known to the ancient nations. However, deep diving progressed only in the early decades of Tehran, Iran the 19th century as the result of advancements in efficient underwater technologies which subsequently led to invention of sophisticated sets of scuba diving in the 20th century. Currently, diving is performed for various purposes including commercial, recreational, mili- tary, underwater construction, oil industry, underwater archeology and scientific assessment of marine life. By increasing popularity of underwater diving, dive-related medical conditions gradually became more evident and created a new challenge for the health care profession- als, so that eventually, a specialty the so-called “diving medicine” was established. Most of the diving-associated disorders appear in the head and neck. The most common of all occupational disorders associated with diving are otologic diseases. External otitis has been reported as the most common otolaryngologic problem in underwater divers. Exostosis of the external ear canal may be formed in divers as the result of prolonged diving in cold waters. Other disorders of the ear and paranasal sinuses in underwater divers are caused by barometric pressure change (i.e., barotraumas), and to a lesser extent by decompression sickness. Barotrauma of the middle ear is the most prevalent barotrauma in divers. The inner ear barotraumas, though important, is less common. The present paper is a brief overview of diving-related ear disorders particularly in scuba div- ers. Keywords: Scuba diving; external otitis; exostosis; ear barotrauma Introduction added to the professional divers’ duties. It has been reported that in the Trojan War istory of breath-hold underwater (1194–1184 BC) divers were employed to Archivediving dates back to antiquity of and destroySID the enemy navy.2 as Edmond, et al, stated “by 4500 The real progress in underwater diving H th BC, it had advanced from the first timid started in the 19 century, when a barrel- dive into an industry supplying the com- like outfit with sleeves and observation munity with shells, food and pearls.” Pearl port was invented in England; later on a as a jewelry was highly valued for ancient hard-hat outfit supplied with compressed Correspondence to Iranians from the Achaemenids period air from a pump was made. In due course, Mohammad-Hossein during the 20th century, by technologic Azizi, MD, Otolaryn- (700–330 BC) and accordingly, based on gologist, Academy of the historical documents, pearl hunting development of underwater diving in- Medical Sciences of the IR Iran, Tehran, was a recognized activity in the first centu- strument, several sets of scuba (acronym Iran ry BC in the Persian Gulf, southern Iran.1 for self-contained underwater breathing Tel: +98-212-293-9869 3 E-mail: [email protected] Afterward, a military activity has been apparatus) were invented. Presently, so- 20 www.theijoem.com Vol 2 Numberwww.SID.ir 1; January, 2011 rev i ew M. H. Azizi phisticated scuba sets are available and death. The most important diving-related they are used in deep diving for commer- disorders are due to changes in pressure— cial, recreational, military, industrial, un- barotraumas;12 The middle ear cavity is derwater construction and scientific pur- commonly affected in divers.13 poses including underwater archeology Major disorders of diving can be clas- and studying marine life. The recreational sified as a) barotrauma which is due to scuba divers use only compressed air com- expansion or compression of gas-filled posed of oxygen and nitrogen—like ordi- spaces in the body including the middle nary air. However, for very deep diving, a ear cavity and paranasal sinuses;13 and b) mixture of helium and oxygen is used. decompression sickness (caisson disease In Iran, underwater diving, especially or colloquially known as divers’ disease, in the Persian Gulf (with an average depth or the bends) which is resulted from re- of 35 m to a maximum of almost 100 m),4 lease of dissolved nitrogen gas into the southern Iran, became more prevalent in blood and tissues on rapid ascent when the past few decades. Nowadays, recre- ambient pressure is suddenly decreased; ational diving is considered as a relatively the disease is presented as body pain es- widespread water sport in Kish Island lo- pecially in the limbs and joints but may cated in Persian Gulf. In addition, profes- also involve the inner ear.13 Deafness and sional diving is also performed for com- vertigo may occur in those with inner ear mercial, navy staff training, underwater involvement.14 construction and oil industry as well as scientific investigations such as underwa- Risk Factors ter archeology and rescue missions.5,6 Mysterious underwater world is very at- Diving injuries were investigated in a re- tractive. Over 15 million people are inter- cent survey on 682 divers. Around 80% of nationally engaged in recreational diving divers had diving license, 32.7% of whom and it is estimated that each year around reported different medical problems such 250 million dives are performed.7 Annual- as hypertension, asthma, diabetes mellitus, ly, about 250 000 new divers receive div- and epilepsy. The researchers concluded ing license8 and more than seven million that there were no significant differences people participate in scuba diving.9 among those with diving license in terms of dive frequency, medical conditions, Health Aspects of Underwater smoking, and alcohol or illicit substance Diving use.15 In another study, the investiga- Archivetors reported of that theSID risk of decompres- Despite its attractiveness, underwater sion sickness may be somewhat more in milieu is potentially an aggressive envi- women divers, which was probably due to ronment for humans. As Sykes wrote, in the different fat distribution in their bod- the underwater world “pressure increases ies.16 Based on the evaluation of pre-dive with depth, visibility is often poor, and and follow-up records of 46 healthy sport temperatures are commonly low.”10 In ad- scuba divers, no relationship has been dition, human body lacks the necessary observed between barotrauma of the pa- adaptive mechanisms found in marine ranasal sinuses and gender, alcohol con- mammals to cope with increased under- sumption, smoking, use of decongestants, water pressure,11 thus, in deep-sea scuba mild nasal septal deviation, and inability diving, divers may develop various medi- to perform the Valsalva or Toynbee ma- cal disorders some of which could lead to neuvers. However, the author added that www.theijoem.com Vol 2 Number 1; January, 2011 www.SID.ir21 rev i ew Ear disorders in diving terial species in the external ear canals of divers was related to the conditions of he- TAKE-HOME MESSAGE lium saturation diving (which allows pro- fessional divers work at depths more than ● Underwater milieu is potentially an ag- gressive environment for humans. 50 m) but within 48 hours after returning to normal atmospheric conditions, the ● In deep-sea scuba diving, divers may normal flora of the external ear canal re- develop various medical disorders turned to Gram-positive bacteriae which such as barotrauma and decompres- became again the predominant microor- sion sickness. ganisms.20-22 ● Barotrauma, decompression sickness Exostosis of the ear canal and noise are among the main etiolo- The prevalence and severity of exostoses gies of hearing loss in different diving of the external auditory canal in a group groups. of experienced breath-hold divers were studied and the findings were compared ● Dive-related otologic disorders include external otitis, exostosis of the ear ca- to the same parameters among surfing nal, middle ear barotrauma and Inner and scuba divers. In this research, 76 male ear barotrauma. and 35 female breath-hold divers were studied. Then, those who completed the divers with a positive history of sinusitis questionnaire (111 of 154 attendees) were or barotrauma of the middle-ear may be at examined by otoscope for any evidence of higher risk for developing paranasal sinus exostoses in the external auditory canals. barotrauma.17 It was found that exostoses were evident in 87.7% of the 204 ears. The severity of Diving-Associated Ear Problems exostoses in breath-hold divers was sig- nificantly lesser than surfing divers, but A significant number of scuba divers expe- greater than scuba divers. The most im- rience dive-related otolaryngologic (ENT) portant predictor of the prevalence and disorders.15 Barotrauma, decompression severity of external auditory exostoses sickness and noise are considered as the in breath-hold divers was the sea surface main etiologies of hearing loss among dif- temperature at the location of open-water 23 ferent diving groups.18 exposure. In a similar study in Japan, 97 military divers from two districts, Mutsu ExternalArchive otitis of (aSID cold area, northern Japan) and Yoko- A study of 429 active experienced divers suka (a warm region, Central Japan) were showed that the most frequent disorder evaluated for the presence of exostosis in was external otitis(43.6%).16,17 The authors their external ear canals. The average sea also reported the predisposing factors of water temperature of the two mentioned external otitis in these divers including lo- districts was different because of their al- cal trauma, removal of lipid from the skin, titude, but the two groups of divers had prolonged exposure to high humidity and similar diving activity. The prevalence of temperature as well as the most common exostosis in the cold area group showed a responsible microorganism, Pseudomo- significant increase as their diving career nas aeruginosa.19 It has also been shown progressed, but the same pattern was not that proliferation of Gram-negative bac- observed among the warm region group.