Sinus Barotrauma: Prevention

Prevention of sinus barotrauma is achieved by refraining from diving with upper respiratory tract infections, sinusitis or rhinitis. Cessation of smoking will reduce the likelihood of mucosal irritation and sinus barotrauma. Avoidance of allergens may assist in persons so predisposed, as may treatment with local steroid nasal preparations. Correction of nasal abnormalities may be needed.

Systemic decongestants such as pseudoephedrine (Sudafed) are often used, as are topical nasal decongestants. Neither drug type is as effective as using the correct equalizing techniques. Positive pressure techniques during descent, such as the Valsalva manoeuvre, assist in aeration of the sinuses as well as the middle ears (as opposed to the passive equalization methods). Feet-first descents are preferable (i.e. head upright), and the techniques used for middle ear equalization (‘equalizing ahead of the dive’; see Chapter 7) are advised. Slow descents and ascents will reduce the sinus damage where there is only marginal patency of the sinus ostia.

Some physicians have found the use of proteolytic or allegedly mucus-softening enzymes to be of value. Well-controlled experimental trials are required to demonstrate any efficacy of these drugs.

Sinus Barotrauma: Treatment

Most of the effects of sinus barotrauma are minor and rapidly regress if diving is suspended and the underlying or consequential inflammatory disorder of the sinus is treated. Patients with a sinus or upper respiratory tract infection may require antibiotics and decongestants. Surgical drainage of acute lesions is rarely indicated, unless there are neurological or other sequelae. Attention is best paid to prevention.

Even mucoceles and chronic sinus disease usually resolve without intervention, if diving is suspended.

In the ‘serious’ cases (the second Australian series), the treatment could be divided into groups of patients:

  1. Those whose disorder cleared up spontaneously and who were advised to not dive until this had happened.
  2. Those who were using inappropriate diving techniques. These have been described previously. These patients usually responded to appropriate regimens of: a. Feet-first descent. b. Positive pressure manoeuvres to autoinflate both middle ears and sinuses, on the surface (immediately before descent) and then at regular intervals of half to 1 metre or so during descent. This is equalization ahead of the dive (see Chapter 7). c. Avoidance of diving exposure during respiratory tract inflammations.
  3. Those who responded to medical treatment of the nasal disorders. This included the topical use of steroid nasal sprays, cromoglycate, topical or generalized decongestants, avoidance of nasal irritants and allergens and cessation of smoking (tobacco or marihuana).
  4. Patients with infective sinusitis, who required treatment of the infections, usually by decongestants and antibiotics. The authors of this text so treat any persistence of symptoms following sinus barotrauma, i.e. symptoms commencing hours after the dive or persisting into the following day.
  5. The intractable group, who required sinus exploration, usually with endoscopy and reconstruction, or nasal surgery. In some cases surgery was required to produce patency of the ostia and to remove polyps, mucocoeles or redundant mucosa that caused obstruction to the ostia. Other times it was needed to improve nasal air flow. Reference in the literature, by Bolger, Parsons and Matson26 in 1990, has been made to the value of surgery in aviators with sinus barotrauma. The guarded enthusiasm of these investigators for functional endoscopic sinus surgery was tempered by the possible complications of this procedure. Nevertheless, endoscopic sinus surgery is advancing rapidly and may offer value to patients with the more serious and chronic cases. With current endoscopic surgical procedures22, the maxillary, ethmoid and sphenoid sinuses can be treated to widen the sinus ostia, thus preventing sinus barotrauma. It is considered the treatment of choice in military aviators in the United States. The frontal sinus is less amenable to this treatment but may be explored in some cases.
  6. The sixth group continued to have difficulties and usually ceased diving.

All patients were strongly advised to not dive during times of upper respiratory tract inflammation (e.g. infections, allergic or vasomotor rhinitis). As with the original series, more than 50 per cent of the divers in the second series had a history of diving with such conditions at the time of the barotrauma.

Some clients were moved between treatments because various measures failed to resolve or prevent problems completely.

Our general impression was that approximately equal numbers fell into each ‘treatment’ group. Various attitudes to the current treatments are discussed in the previously cited references and diving medical texts.

Sinus Barotrauma: Differential Diagnosis

In 6 per cent of the ‘serious’ cases, an initial diagnosis of decompression sickness was made, with the case subsequently demonstrated to be sinus barotrauma, often with complicating sinus infection. At the time of presentation, which could be some hours after the dive, the clinical pattern was confused with cerebral decompression sickness and treated as such. These were understandable mistakes, and there should be no hesitation in administering hyperbaric therapy if there is any doubt regarding the diagnosis. It would be preferable to miss and mistreat a case of sinus barotrauma than miss and mistreat a case of cerebral decompression sickness.

The only other case of incorrect diagnosis was one subsequently attributed to a dental aetiology (barotrauma associated with pneumatization around a carious tooth), and this case was therefore not included in the series.

Lew and his colleagues18 referred not only to the symptoms of sphenoidal sinusitis, but also to its association with ‘deep sea diving’. Sphenoidal sinus involvement occurred in 6 per cent of the ‘serious’ cases. It is important because of the failure of clinicians to recognize it and to not appreciate its potentially serious complications (Case Report 8.3).

Sphenoidal sinusitis is not easy to demonstrate with plain x-ray films, but it is often obvious on MRI or CT scans.


CASE REPORT 8.3: ID was not part of the ‘serious’ case series, but he sustained clinically obvious sphenoidal sinus barotrauma of descent. This caused some concern because of the proximity to other important structures around this sinus and the possibility that the computed tomographically verified space-occupying lesion was neoplastic. Although operative intervention was contemplated in this case, the lesion (a mucocele or haematoma) cleared up within 2 weeks, following abstinence from diving.

Sinus Barotrauma: Surgical Emphysema

This disorder has been seen on a number of occasions and was described previously5. The tracking of air expanding in the sinuses and erupting into the surrounding tissues can manifest as orbital surgical emphysema (usually from the ethmoidal sinus though a fracture of the egg-shell–thin lamina papyracea; see Plate 2). In other instances, the air has passed from other sinuses, and the disorder can first occur as a localized manifestation in the facial tissues.

Sinus Barotrauma: Pneumocephalus/Haemorrhage/Neurological Involvement

The presence of pneumocephalus, in association with sinus injury in general medicine, has been well recorded by Markham19, and it is one of the dangers associated with sinus barotrauma5. It has been well demonstrated by Goldmann20 (see Figure 9.3).

Pneumocephalus results from the expansion during ascent of gas in a space (mastoid, ethmoidal and sphenoidal sinus) that has been partly occupied by blood and fluid from the descent barotrauma. A rupture into the cranial cavity, with air and/or fluids, produces an excruciating and sudden headache, with the pathological features demonstrated by radiology, CT brain scans or MRI. The temporal bony roof over the sinuses is frequently very thin or incomplete, allowing for the contents of this (air, blood) to rupture into the middle cranial fossa, into the epidural areas21. This condition is not infrequently observed at autopsy when the diver has descended while alive but unconscious, inducing para-nasal sinus barotrauma, and then being brought to the surface, where the gas space has expanded, even though the diver may have died.

Extension of infections following sinus barotrauma and subsequent sinusitis may result in orbital cellulitis, meningitis and other neurological problems.

Orbital haemorrhage may also result from the pressure gradient, with potential vision-threatening ocular complications. Sinus mucocoeles, produced during barotrauma, can also cause space-occupying lesions with neurological sequelae, including optic neuropathy and blindness. Demonstrable on MRI, these disorders require referral of the patient to an ophthalmic surgeon.

Sinus Barotrauma: Acute Sinusitis

Campbell1 stated that infection occurs only rarely, and his series may be equitable, in terms of selection, with the initial Australian survey6. If, however, one considers the second Australian survey, with its more serious cases, then the infection complications are more frequent.

Acute sinusitis developed some hours after the dive and extended into subsequent days, in 28 per cent of the severe cases, usually with an exacerbation of pain over the affected area, a purulent nasal discharge and generalized systemic symptoms.

The patients with sinus barotrauma who subsequently developed a sinus infection possibly did so because of the haemorrhage and effusion in the sinus. This condition becomes a culture medium for organisms introduced by the flow of air into the sinus during descent. An occasional case of orbital cellulitis may extend from the ethmoidal or maxillary sinusitis, and it is a medical emergency. One case proceeded to blindness (Case Report 8.2). It is for this reason that the authors of this text now vigorously treat with antibiotics any persistence of symptoms following sinus barotrauma, i.e. commencing hours after the dive or continuing into the following day.


CASE REPORT 8.2: A 24-year-old professional trainee diver descended to 40 msw for 30 minutes despite an upper respiratory tract infection and descent-induced pain over his right maxilla and orbit. He slowed his descent to reduce these symptoms, but re-developed a sudden severe pain over his right cheek on ascent. Bleeding was evident after ascent, in his face mask. Three days later he complained of persistent right facial pain, blocked nose and epistaxis. The next day he had swollen right eyelids, mucopurulent nasal discharge and mild pyrexia. X-ray studies confirmed right maxillary and ethmoidal sinusitis. Antral washout and antibiotics were administered but did not prevent an extension of the orbital cellulitis and retinal artery thrombosis with permanent and total right-sided blindness. (From Bellini MJ. Blindness in a diver following sinus barotrauma. Journal of Laryngology and Otology 1987;101:386–389.)

Sinus Barotrauma: Maxillary Nerve Involvement

In 4 per cent of the cases the pain was referred to the upper teeth, on the same side as the affected maxillary sinus. This is presumably an involvement of the posterior superior alveolar nerve. In another 4 per cent there was involvement of the infraorbital nerve, with numbness over the skin of the cheek on the same side.

Two separate branches of the maxillary division of trigeminal nerve can thus be affected as they traverse the maxillary sinus16,17: the infraorbital nerve as it runs along the wall of the maxillary sinus and the posterior superior alveolar nerve as it runs along the lateral or inferior wall of the maxillary sinus. The former produces a numbness or paraesthesia over the cheek and the latter a numbness over the upper teeth, gums and mucosa on the same side. In some cases pain and hypersensitivity are observed. Problems with neurapraxia are more common with ascent than descent, a finding suggesting that impaired circulation is more frequent than congestion or haemorrhage of the nerve as a basis of the presentation.

There is a possibility of involvement of any division of the trigeminal nerve, including its maxillary division, with involvement of the sphenoidal sinus18.

Sinus Barotrauma: General Symptoms

In a small number of the cases (8 per cent), some additional symptoms did not appear to be easily explicable on the basis of local sinus disease. These included nausea or vomiting, a sensation of impending syncope and disorientation at the time of injury. These occurred in the more dramatic cases of sinus barotrauma.

Sinus Barotrauma of Ascent

This disorder may follow the occlusion of sinus openings by mucosal congestion, folds or sinus polyps, preventing escape of expanding gases (Figure 8.4). The ostium or its mucosa will then blow out into the nasal cavity, with or without pain, and haemorrhage commonly follows. Bleeding from the nostril on the same side as the sinus disorder is sometimes the only manifestation. This disease is aggravated by rapid ascent, as in free ascent training, emergency ascents, submarine escape and so forth.

Figure 8.4 Diagrammatic changes of sinus barotrauma from obstruction of sinus ostia on the surface (top), then descent to 10 metres (2 ATA), halving the sinus air volume and replacing this with fluid and mucosal swelling (middle). During ascent, the gas expands and discharges fluid (blood, effusion).
Figure 8.4 Diagrammatic changes of sinus barotrauma from obstruction of sinus ostia on the surface (top), then descent to 10 metres (2 ATA), halving the sinus air volume and replacing this with fluid and mucosal swelling (middle). During ascent, the gas expands and discharges fluid (blood, effusion).

Uncommonly, other manifestations may develop. If the expanding air cannot escape through the sinuses, it may fracture the walls and track along the soft tissues and cause surgical emphysema. Rupture of air cells may cause severe and sudden pain, often affecting the ethmoidal or mastoid sinuses, on ascent. Occasionally, the air may rupture into the cranial cavity and cause a pneumocephalus or a small intracranial haemorrhage.

Sinus Barotrauma of Descent (Sinus Squeeze)

If a sinus ostium is blocked during descent, mucosal congestion and haemorrhage compensate for the contraction of the air within the sinus cavity. During ascent, expansion of the enclosed air expels blood and mucus from the sinus ostium. Ostia blockage may be the result of sinusitis with mucosal hypertrophy and congestion, rhinitis, redundant mucosal folds in the nose, nasal polyps and so forth.

As described with ear barotraumas, sinus barotraumas are more frequently noted in female divers and in the young; however, chronic sinus problems are an increasing problem with age and excessive diving frequency (more in dive instructors than in dive masters15).

Symptoms include pain over the sinus during descent. It may be preceded by a sensation of tightness or pressure. The pain usually subsides with ascent but may continue as a persistent dull ache for several hours. On ascent, blood or mucus may be extruded into the nose or pharynx, on the same side as the sinus disease.

Headache developing during the dive, with the diver neither ascending nor descending, should not exclude the diagnosis of sinus barotrauma. When this develops at considerable depth, the sedative effects of narcosis may distort the clinical features. Also, small changes of depth may not be particularly noticeable but produce a misleading history.

The pain is usually over the frontal sinus; less frequently it is retro-orbital and probably sphenoidal. Maxillary pain is not common but may be referred to the upper teeth on the same side. Although the teeth may feel hypersensitive, abnormal or loose, they are not painful on movement. Coughing, sneezing or holding the head down may aggravate the pain and make it throb. Numbness over the maxillary division of the fifth nerve is possible (see later).

The superficial ethmoidal sinuses near the root of the nose occasionally rupture and cause a small haematoma or discolouration of the skin between the eyes (see Figure 8.2).

Discomfort persisting after the dive may result from fluid within the sinus (continuous from the dive), infection (usually starts a few hours after the dive) or the development of chronic sinusitis or mucocoeles.

Investigations

Sinus x-ray examination, CT or MRI scan may disclose thickened mucosa, opacity or fluid levels. The opacities produced by the barotrauma may be haemorrhagic, serous or mucous cysts. The maxillary and frontal sinuses are commonly involved. The ethmoid and sphenoidal sinuses may also be affected. The newer imaging techniques can clearly demonstrate these features.


CASE REPORT 8.1: DN, a 22-year-old sports diver, occasionally noticed a trace of blood from his face mask following ascent. He had often complained of nasal blockage and had various treatments for this, including cautery. His first dive to 12 metres for 10 minutes was uneventful. After a brief surface interval he again descended, but he was unable to proceed beyond 6 metres because of a severe tearing headache in the frontal region. He equalized his face mask, and this provided some relief. He then continued the descent feet first but still had some slight pain. On reaching the bottom, the severe sharp pain recurred. During ascent it lessened in severity, but on reaching the surface he noted mucus and blood in his face mask. A dull frontal headache persisted for 3 hours after the dive. Examination revealed a deviated nasal septum to both right and left, with hyperaemic nasal mucosa. X-ray studies showed gross mucosal thickening in both maxillary sinuses, the right being completely opaque. There was also some slight shadowing on the right frontal sinus. The radiological signs cleared over the next 2 weeks. Because the airways were patent on both sides of the nasal septum, operative intervention was not indicated. The patient’s nasal mucosa returned to normal after he abstained from cigarette smoking.

Diagnosis: sinus barotrauma of descent.