Thursday, January 19, 2012

Can divers be affected by a sinus barotrauma?

Can divers be affected by a sinus barotrauma?



Sinus barotrauma is the result of disparate pressure between the nose and sinuses as a result of ostial insufficiency. Even if the sinus ostium is sufficiently large to permit a gradual equalization of pressure, a person cannot be accommodated to the rapidly changing pressure that occurs during scuba diving. For this reason, sinus barotrauma is more commonly observed in divers.




Barotrauma of the sinuses in diving was reported more than 50 years ago. 7,8 The most common symptom is pain referred to the frontal area, although radiological examination showed that the maxillary sinus was most affected. X-rays showed a mucosal thickening and air/fluid levels. Half of the patients present a recent upper respiratory infection or symptoms referable to nasal disease.

The sinonasal symptoms and radiographic findings 10 were observed in a more recent study of 50 scuba divers affected by sinus barotrauma. 28% of patients developed an acute sinusitis 10, and another 14% of patients presented a preexisting chronic sinusitis (condition that predisposed the sinuses to recurrent barotrauma). The maxillary nerve involvement is the only neurological complication of sinus barotrauma. Possibly, repeated diving may foster permanent sinus mucosal changes or progressive ostial insufficiency. 10

It is important to differentiate between recurrent sinus barotrauma and chronic sinusitis. Patients with recurrent sinus barotrauma may have no clinical or radiological evidence of sinusitis between barotraumatic episodes. Upper respiratory infection, rhinitis, sinusitis, and intranasal pathology (e.g., nasal polyps or septal deviation) are a few factors that can compromise the capacity of the sinus ostia to accommodate the large, rapid pressure changes that occur during scuba dives. Ostial insufficiency always puts patients at risk of developing barotrauma when scuba diving. There are also some important barriers that separate the central nervous system and ocular globe from the nose and sinuses like, in all probability, the nasal mucosa, periosteum and dura. They are important in preventing the spread of infections from the nose to the eye or central nervous system, avoiding the complications reported here that would otherwise be much more common.

The air locked in patients who had a history of chronic sinusitis, may have formed within the sinuses or nasal cavity, the hyperplastic polypoid mucosa functioning like a ball valve, and both circumstances preventing highly pressurized air inspired at depth from escaping as the patients ascended. Complicating factors included the repeated, forceful Valsalva manoeuvre by both divers at depth; this manoeuvre can produce more than 250 mm Hg of pressure and could have forced pus through a small defect in the cribriform plate into the intracranial cavity (in the first diver) and air into the orbit and middle ear (in the second diver). As diver 2 ascended, the air in the orbit and middle ear expanded and compromised blood flow through the retinal artery. Pressurized air in the middle ear thus probably caused the inner ear barotrauma in each diver, as well as repeated episodes of facial palsy. 14

When examining patients with recurrent sinus barotrauma, clinicians should first rule out causative pathology by examining the nasal cavities endoscopically and possibly by obtaining a CT-scan of the sinuses. Divers with recurrent sinus barotrauma should be advised not to dive with a congested nasal cavity (e.g., during an upper respiratory infection or during an episode of either allergic or nonallergic rhinitis). In addition, intranasal disease (e.g., nasal polyps or septal deviation) in these divers may require correction to avoid compromising the ostiomeatal complex. Divers with persistent difficulty equalizing pressure in the ear and sinuses should be taught methods of equalizing this pressure. These divers should be advised to begin this equalization while at the surface of the water, then to descend slowly (with feet descending first) and to equalize continuously until a depth of 20 feet or more is reached. Those who have persistent difficulty clearing their ears and sinuses should be advised not to dive at all.

Patients who show evidence of chronic sinusitis should be treated with appropriate medical management. If radiological evidence of disease persists, functional endoscopic sinus surgery should be considered. If no clinical or radiological evidence of ostial insufficiency persists, then a pressure test should be conducted either in a hyperbaric chamber or (more practically) in a 14-foot or deeper swimming pool. If no pain develops at this depth, diving may be resumed. However, these patients must be warned that clearing may still be difficult and that this problem could result in disabling or life-threatening injuries.

Divers who present chronic rhinosinusitis should be instructed on the optimal control of their sinus disease and on non-forceful methods of clearing. Only when medical management fails, endoscopic sinus surgery is beneficial for preventing recurrent episodes of barotrauma in divers 11,13 who have recurrent or chronic sinusitis.

BIBLIOGRAPHY

1.
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Campbell PA. Aerosinusitis: its causes, course and treatment. Ann Otol 1944; 53:291–301. 


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Flottes L. Barotrauma of the ear and sinuses caused by underwater immersion [in Spanish]. Acta Otorinolaryngol Iber Am 1965; 16:453–483.

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10.
Edmonds C. Sinus barotrauma: a bigger picture. SPUMS J 1994; 24(2):13–19. 


11.
Taniewski M, Graczyk M, Laba L. Mucous membrane of the nose and paranasal sinuses in professional divers. Bull Inst Marit Trop Med Gdynia 1979; 30:237–244.

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Parsons DS, Chambers DW, Boyd EM, Long-term follow-up of aviators after functional endoscopic sinus surgery for sinus barotrauma. Aviat Space Environ Med 1997; 68:1029–1034.

13.
Bartley J. Functional endoscopic sinus surgery in divers with recurrent sinus barotrauma. SPUMS J 1995; 25(2):64–66. 


14.
Becker GD. Recurrent alternobaric facial paralysis resulting from scuba diving. Laryngoscope 1983; 93:596–598.

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