Barosinusitis

The paranasal sinuses have rigid walls with relatively small ostia for gas exchange and mucus transport. Physical gas laws, particularly Boyle's Law, apply to this space. Boyle's Law states that at constant temperature, the volume of a gas is inversely proportional to the pressure placed upon it.

To show how Boyle's Law affects the sinuses, consider the case of an individual with normal sinuses exposed to pressure changes while flying in an unpressurized aircraft. As the individual transitions to higher altitude, the ambient pressure surrounding the sinus cavity decreases, and the air in the sinuses expands and equalizes through the natural ostium. Upon descent, ambient air pressure increases, the air in the sinuses contracts, and air moves into the sinus cavity, preventing a pressure gradient from developing.

Now consider the same flight in someone who has an upper respiratory tract infection (URTI) with tissue edema and secretions blocking the natural sinus ostia. In this individual, tissue edema and debris will not allow free pressure equalization. Again, as the individual moves up in altitude, the ambient pressure decreases, and volume in the sinus cavity increases. A positive pressure develops in the sinus. With this positive pressure, tissue edema gradually decreases enough to allow debris and air to escape the natural ostium. Air pressure then equalizes. When the individual descends, the ambient pressure increases. Pressure cannot equalize across the nasal cavity to the sinus because of blockage at the ostium. Air volume decreases in the sinus cavity, creating a negative pressure.

At this point, a condition exists in which the volume of the sinus must be filled if the pressure gradient is to be eliminated. In mild-to-moderate cases, vascular engorgement and generalized submucosal edema occur. Over time, transudate and mucus fill the volume, reducing negative pressure and decreasing symptoms. In severe cases, especially with rapid onset, the sinus mucosa is stripped from the subjacent bone, resulting in severe pain and hematoma formation.

Frequency

United States

Prevalence is approximately 3-4 episodes per 100,000 exposures in a generally healthy population.

• In contrast, middle ear barotrauma (aerotitis media) is approximately 6-10 times more prevalent than barosinusitis.

• Frontal sinuses are most often affected, followed by maxillary sinuses.

• Ethmoid sinuses are infrequently affected as isolated events.

• Data are heavily skewed toward people who participate in activities subject to rapid pressure changes.

International

A Danish study conducted via questionnaire determined that compared with pilots who had answered the same questionnaire 10 years earlier, the proportion of responding pilots in whom one or more ear-nose-throat (ENT) barotraumas had occurred had increased from 19.5% to 27.9% for barosinusitis and from 37.4% to 55.5% for barotitis media.[6]

Race

Race predilection is not widely reported.

Sex

Sex predilection is not widely reported.

Age

Barosinusitis is not typically reported in children. Frontal sinuses are most frequently affected, and these do not fully develop until late adolescence. In addition, children do not routinely participate in activities that lend themselves to rapid pressure changes.

Differentiate sinus barotrauma from other causes of facial pain and headache. The history is particularly important in shortening the differential. In sinus barotrauma, a condition of barometric pressure change always exists either during or shortly after onset of symptoms.

With mild sinus barotrauma, the patient reports the following:

• Mild pressure or pain over 1 or more of the sinuses that develops after return to sea level or starting point
• Worsening congestion
• Occasional epistaxis

With more severe sinus barotrauma, the patient notes the following possibly incapacitating signs and symptoms:

• Sudden onset of typically severe and sharp pain and pressure - Pain is typically in the forehead, midface, or retro-orbital area
• Epistaxis

Physical findings may be relatively sparse in mild cases of barosinusitis. In severe cases, the patient may have marked pain in the forehead, face, and upper teeth. This pain is typically unilateral. Erythema, edema, congested mucous membranes, epistaxis, and tenderness to palpation of the face may occur.

The following activities and conditions place individuals at particular risk for barosinusitis:

• Scuba and sport diving[7]

• Sky diving

• Flying in military/high-performance aircraft

• URTI or sinusitis in persons exposed to pressure changes

• Poorly controlled allergies or anatomic abnormalities of the nose and paranasal sinuses

Wang et al found that out of 605 cases of aviatic nasal disorders among air-crew members, 55 (9%) involved sinus barotrauma.[8]

A study by Smerz of 400 Hawaiian scuba divers did not find a significant association between the use of vasoconstrictive sympathomimetic decongestants by scuba divers to avoid otic and sinus barotrauma and the development of decompression sickness (DCS), even though vasoconstriction is considered to be an important factor in DCS.[9]

See the list below:

• Laboratory assessment adds little to the evaluation of barosinusitis.

Radiologic assessment is not usually necessary to establish the diagnosis but may help to indicate location and to search for underlying causes.

Plain films are useful to isolate location. The usual finding is mucosal edema, which can range from slight thickening to total opacification of one or more sinuses. There may be air-fluid (ie, blood) levels. Hematoma formations, usually in the frontal sinus, are smooth and oval; they may be small or may nearly fill the sinus.

CT scans are considered the criterion standard for imaging assessment of barosinusitis. Obtain coronal and axial views. CT scanning accurately defines involved sinuses, extent of any hematoma, and mucosal thickening. The study can suggest predisposing factors (eg, septal deviation, middle meatus and turbinate abnormalities, nasal polyposis, underlying mass). CT scanning is an excellent tool for surgical planning.

MRI is similar to CT scanning in predicting involved sinuses, but it does not provide bony detail. MRI is better than CT scanning in differentiating paranasal sinus masses, although it is not as useful as CT scanning in surgical planning and can be more time consuming to obtain.

Other tests (eg, ultrasonography) are not typically used to aid in diagnosis or treatment. Transillumination of the sinuses may provide some additional information on location of barotrauma, but it is unreliable and does not change treatment.

Begin treatment at the first sign of barotrauma. Treatment is accomplished most simply by returning to the altitude at which symptoms occurred or, in the case of diving, returning to the surface. Decongest the nose with liberally applied topical agents, and then gradually descend to ground level. Unfortunately, immediate treatment is not always possible, and treatment often begins after the fact.

Medical therapy is generally directed toward pain control, establishing ventilation, and preventing infection.

• Pain control

  • Oral agents are usually effective.

  • Severe pain may require the use of narcotics.

  • Products that contain aspirin should probably be avoided in the short term to minimize the risk of worsening hematoma formation.

• Establishing ventilation

  • Topical decongestants include 0.05% oxymetazoline and 0.5-1% phenylephrine.

  • Oral decongestants include phenylpropanolamine ( recalled from the US market) and pseudoephedrine.

  • In general, antihistamines are avoided because they tend to dry mucosa and inspissate secretions, although they may be useful if the underlying disease process includes poorly controlled allergies.

• Preventing infection

  • Blood and transudate from traumatized mucosa provide a rich medium for bacterial growth.

  • This environment, combined with damaged mucosa, inability to clear secretions, and altered oxygen tension, sets the stage for secondary bacterial infection (if not already present as the underlying cause of URTI).

  • A course of antibiotics may prevent secondary infection and hasten recovery.

  • In the acute setting, the first-line antibiotic is amoxicillin. In patients who are allergic to penicillin, trimethoprim/sulfamethoxazole is a reasonable first-line medication. Other choices include extended-spectrum penicillins, cephalosporin, clindamycin, extended-spectrum macrolides, and quinolones.

Surgical therapy is designed to restore sinus ventilation. Conventional therapy with septoplasty, turbinectomy, antral windows, the Caldwell-Luc operation, external or transantral ethmoidectomy, nasal polypectomy, and frontal sinus trephination has had variable efficacy. Endoscopic sinus surgery has substantially increased the chance of returning the patient to full activities.

• If oral agents fail to relieve pain and pressure, or if pain and pressure do not resolve over 24 hours, consider antral puncture/washout to rapidly equilibrate pressure and to clear sinus blood and other debris. This has minimal effect on the middle meatus and may not clear symptoms from ethmoid and frontal disease. Septoplasty and turbinectomy may help as a preventive measure, depending upon the clinical presentation.

• Endoscopic sinus surgery

  • Recurrent sinus barotrauma due to anatomic derangement has been managed effectively with endoscopic sinus surgery. Parsons et al reported their results on a group of military aviators, 98% of whom returned to flying after treatment.[10]

  • In another group of military pilots, aircrew, and divers, all patients returned to full duty after approximately 14- to 21-days' recovery time. In general, the surgery is designed to establish ventilation and minimal hole techniques are typically effective; however, the particular surgery must be individualized for optimal results. Nasal septal deflection, if clinically significant, is corrected at the time of endoscopic sinus surgery.

  • These studies use individuals who represent a select group of people who do not have a history of underlying mucosal disease (eg, allergy, polyposis). Individuals with underlying disease may also benefit from endoscopic sinus surgery, but they may require ongoing medical therapy for maximal results. Ongoing medical therapy must be highly individualized and closely monitored. Such medical therapy may disqualify, either temporarily or permanently, the individual from those activities that resulted in sinus barotrauma in the first place. This is especially true for aviators and divers in whom incapacitation from acute sinus barotrauma may be substantially more than an inconvenience.

  • CT scan imagery should determine the extent of sinus surgery; but, in general, limit surgery to minimal dissection and debridement techniques. This minimizes tissue damage and healing time yet establishes patent ostia that prevent recurrence of pressure gradient and sinus symptoms.

  • One more recent addition to surgical therapy of the paranasal sinuses is the balloon sinuplasty.[11] This technique may be uniquely suited to establishing sinus ventilation, with the minimum tissue manipulation of any surgical techniques currently available. Potential advantages include reduced healing time and reduced risk of delayed surgical complications (obstructive scarring/stenosis).

Depending upon the extent of surgery, most patients can return to full activity within 1-3 weeks following surgery.

Commercial airline travel is generally permitted within 2-3 days, as is swimming on the water surface.

The goal of pharmacotherapy is to reduce morbidity and prevent complications.

Class Summary

Decongestants establish ventilation of the sinuses and relieve pressure, pain, and edema. Combine topical and oral decongestants in most cases, especially for acute symptoms. Topical agents are frequently useful when oral agents are contraindicated.

Oxymetazoline 0.05% (Afrin, Allerest, Chlorphed, Dristan)

First-line therapy for topical decongestion. Applied directly to mucous membranes, stimulating alpha-adrenergic receptors and causing vasoconstriction. Decongestion occurs without drastic changes in blood pressure, vascular redistribution, or cardiac stimulation.

Phenylephrine nasal (Neo-Synephrine)

First-line topical decongestant if a shorter-acting agent is preferred. Strong postsynaptic alpha-receptor stimulant with little beta-adrenergic activity that produces vasoconstriction of arterioles in the body.

Phenylpropanolamine (Rhindecon, Unitrol, Phenyldrine)

Recalled from US market. First-line oral decongestant. Epinephrine stores are released under phenylpropanolamine stimulation and produce alpha- and beta-adrenergic stimulation. These effects may increase outlet resistance.

Pseudoephedrine (Actifed, Sudafed, Afrin)

First-line oral decongestant. Stimulates vasoconstriction by directly activating alpha-adrenergic receptors of the respiratory mucosa. Induces bronchial relaxation and increases heart rate and contractility by stimulating beta-adrenergic receptors.

Class Summary

Antibiotics control infection either as an inciting factor in the barosinusitis or as a sequela of the barosinusitis.

Amoxicillin/clavulanate (Augmentin)

Drug combination treats bacteria resistant to beta-lactam antibiotics. First-line therapy for persons not allergic.

Trimethoprim/sulfamethoxazole (Bactrim, Septra)

First-line therapy in patients allergic to penicillin, although adverse effect profile may make other agents more desirable.

Cefuroxime (Ceftin, Zinacef)

Second-line therapy, but may be first-line therapy in patients who are allergic to penicillin.

Amoxicillin (Trimox, Amoxil)

Interferes with synthesis of cell wall mucopeptides during active multiplication resulting in bactericidal activity against susceptible bacteria.

Class Summary

Acetaminophen, with or without codeine, is useful for pain control.

Codeine/acetaminophen (Tylenol and codeine)

First-line analgesic for severe pain. Fixed combination Tylenol #3 is 300-mg acetaminophen with 30-mg codeine.

Acetaminophen (Feverall, Tempra, Tylenol)

DOC for pain in patients with documented hypersensitivity to aspirin, NSAIDs, upper GI disease, or on oral anticoagulants.

See the list below:

• Depending on the clinical situation, the vast majority of patients undergoing endoscopic sinus surgery may return to full activities within 1-3 weeks following surgery.

• Warn patients to avoid activities that may be hazardous (eg, piloting aircraft, diving) until the attending surgeon is sure the patient is fully recovered.

• Remember that other governing agencies (eg, Federal Aviation Administration, Department of Defense) may have ultimate authority over granting the patient's request to return to work or activity (eg, commercial or military flying or diving).

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• Prevention is best accomplished by avoiding ambient pressure changes. This is particularly true when the individual attempts to fly or dive while they have a URTI, cold, or poorly controlled nasal allergy.

• Repeated attacks of acute barosinusitis can cause permanent damage of the paranasal sinus mucosa, which leads to recurrent barosinusitis. This condition results from hematoma formation and fibrosis and chronic mucosal thickening, which can further impede adequate sinus ventilation.

See the list below:

• Complications of barosinusitis are unusual, but they may include the following:

  • Orbital cellulitis, abscess, or hematoma

  • Pneumocephalus or subcutaneous emphysema

  • Complications associated with paranasal sinusitis

See the list below:

• Isolated barosinusitis in a previously healthy individual is most commonly due to flying or diving with acute URTI or sinusitis. These patients generally do quite well with conservative treatment. Recurrent acute barosinusitis suggests fixed pathology of the paranasal sinuses and is more likely to require surgical therapy to establish ventilation. Prognosis is still excellent in previously healthy patients. Those with poorly controlled allergy, nasal polyposis, or extensive mucosal disease may not do as well in terms of returning to full activity.

See the list below:

• Strongly caution individuals involved in work or recreation activities that include acute pressure changes not to participate if they are not 100% physically qualified.

• If symptoms of barosinusitis occur while diving, return to the surface. If flying, return (usually climb) to the altitude at which symptoms first started, use topical decongestants if available, and start a slow descent as symptoms allow. The Valsalva maneuver may be helpful and is more effective after topical decongestion.