Ear barotrauma

INTRODUCTION — 

Ear barotrauma occurs when pressure differences between the middle ear and the outside environment distort the tympanic membrane (TM), leading to discomfort, hearing loss, and injury.

This topic will focus on the clinical manifestations, diagnosis, treatment, and prevention of ear barotrauma. Other issues related to eustachian tube dysfunction are discussed in detail elsewhere. (See "Eustachian tube dysfunction".)

MIDDLE EAR ANATOMY AND FUNCTION — 

The middle ear is an air-filled space, separated from the external environment by the tympanic membrane (TM) laterally and the Eustachian tube anteromedially (figure 1). Pressure within the middle ear must match that of the environment for the TM to vibrate normally. During normal physiologic function, air in the middle ear is absorbed slowly by the mucous membrane lining and is continually replaced by the opening of the Eustachian tube [1]. This happens normally when one swallows or yawns, during which time airflow can occur.

The Eustachian tube extends from the middle ear to the nasopharynx and is made up of two parts (figure 1):

●The posterior half leading from the ear is a bony tube lined with mucosa that does not change shape.

●The anterior half is made of soft tissue that is mucosa-lined; it is normally collapsed.

The Eustachian tube opens momentarily during swallowing or yawning due to actions of the levator veli palatini and the tensor veli palatini muscles. These muscles elevate and tense the palate and simultaneously open the Eustachian tube. This ensures that the eustachian tube is only open when it is protected against reflux from the oral cavity by elevation of the soft palate to close off the nasopharynx. The Eustachian tube also needs to be closed most of the time to prevent TM motion with respiration. (See "Eustachian tube dysfunction", section on 'Anatomy' and "Eustachian tube dysfunction", section on 'Normal Eustachian tube function'.)

ETIOLOGY AND PATHOGENESIS

Effect of pressure differential — Mild pressure differences between the middle ear and external environment can usually be equilibrated through the Eustachian tube. When there is increased pressure in the middle ear compared with the environment, the Eustachian tube passively opens and vents off the positive pressure air; this passive opening typically occurs with a pressure differential of 15 mmHg [2]. In contrast, when the middle ear pressure is lower than the surrounding atmosphere, the Eustachian tube must actively be opened (such as by swallowing or yawning) to allow for airflow into the middle ear.

When there is a large or rapid ambient pressure change, or when Eustachian tube dysfunction is present, the middle ear may be unable to equalize pressure with the external environment. Pathophysiologic changes of barotrauma begin to develop at an 80 mmHg pressure differential. These changes include stretching of the tympanic membrane, bruising and bleeding in the tympanic membrane, and formation of fluid exudates in the middle ear. Eventually, if the pressure differential reaches 100 mmHg or greater, injury can progress to middle ear damage or tympanic membrane (TM) rupture [2].

In more severe cases, inner ear barotrauma with rupture of the round and oval membranes separating the middle and inner ear may occur (figure 2) [2,3]. This can result in formation of a perilymphatic fistula, leading to severe vertigo, sensorineural hearing loss, and nystagmus due to loss of perilymph from the inner ear.

Role of Eustachian tube dysfunction — Inadequate Eustachian tube function can lead to difficulty equalizing air pressure between the middle ear and the outside environment, predisposing to ear barotrauma.

Eustachian tube dysfunction may occur due to any condition that causes inflammation of the nasopharyngeal mucosa. This includes infectious causes such as upper respiratory infection and acute otitis media, as well as noninfectious causes such as environmental allergies, irritants, or acid reflux. In addition, anatomic abnormalities such as increased tissue mass in the nasopharynx, enlarged adenoids, and nasopharyngeal tumors can also obstruct adequate middle ear ventilation. (See "Eustachian tube dysfunction", section on 'Pathophysiology of Eustachian tube dysfunction'.)

Common mechanisms of injury

Flying — Flying is the most common cause of ear barotrauma [4,5]. Commercial aircraft have pressurized cabins, with the pressure generally equal to that at 7000 to 10,000 feet, not sea level. This difference in pressure in itself can be enough to cause barotrauma.

As the plane ascends, outside barometric pressure decreases, and air must leave the middle ear to balance it. This occurs passively via the Eustachian tube. In contrast, during descent, when the outside pressure increases, air must enter the middle ear via active opening of the Eustachian tube (eg, by swallowing or yawning). Ear barotrauma is more common during descent, with up to 90 percent of individuals with a history of barotrauma reporting that symptoms occurred during descent [5].

Diving — Middle ear barotrauma on descent is the most common diving injury [6,7]; one survey of approximately 1800 divers found that over 80 percent had experienced prior middle ear barotrauma [7]. While pressure changes due to flying are less than one atmosphere, pressure changes with diving can be several atmospheres, often resulting in more severe injuries [6,8-13]. Specifically, descending every 33 feet in water is equal to an increase of one atmosphere (760 mmHg). Large pressure differences between the middle ear and the surrounding water can lead to the same injuries as with flying, and also potentially lead to inner ear barotrauma. (See "Complications of SCUBA diving", section on 'Ear barotrauma'.)

Blast injuries — Blast injuries can occur with greater frequency in settings of war and terrorist attacks; they can also be seen in mining and construction industries. Ear barotrauma results from the air pressure wave generated by an explosion [14]. This pressure change is too rapid to allow for the normal equalization of pressures. Injuries include bruising of the TM, bleeding into the TM and middle ear, TM rupture, ossicular disruption, and inner ear injury [15-19].

Other — Less frequent causes of barotrauma include use of decompression chambers and hyperbaric oxygen chambers [20-22]. Barotrauma symptoms have also been reported during skydiving [23] as well as during use of continuous positive airway pressure (CPAP) [24].

CLINICAL MANIFESTATIONS — 

Symptoms of ear barotrauma vary based on severity. Mild barotrauma typically causes ear pain and pressure due to stretching of the tympanic membrane (TM). If injury progresses to TM rupture, the pressure differential is equalized and ear pain and pressure may be suddenly relieved. Severe injuries often cause hearing loss, vertigo, and tinnitus.

Ear barotrauma can be either unilateral or bilateral; in patients with bilateral symptoms, usually one side is more severely affected.

In one survey of approximately 1500 divers with a history of middle ear barotrauma, the most frequently reported symptoms of middle ear barotrauma were ear pain (80 percent) and ear pressure (52 percent) [7]. Less common symptoms of middle ear barotrauma were vertigo (11 percent), hearing loss (6 percent), and tinnitus (5 percent). The majority of patients (67 percent) reported symptom resolution within two minutes; most others experienced symptom resolution within two hours (23 percent). Symptoms rarely persisted beyond two days (3 percent).

In contrast, in a review of divers with inner ear barotrauma, the most frequently reported symptoms were hearing loss (90 percent) and tinnitus (73 percent); vertigo was also fairly common (46 percent) [3].

Otoscopic examination is often normal, especially in mild cases of ear barotrauma. Possible abnormal findings include:

●Swelling of the TM

●Bleeding into the TM due to tears in blood vessels along the malleus (picture 1)

●Middle ear effusion (picture 2)

●Hemotympanum (bleeding into the middle ear) (picture 3)

●TM perforation (picture 4)

In one small study of middle ear barotrauma related to air travel, the most common examination finding was hemotympanum (seen in 47 percent of patients) [25]. Less common findings of middle ear trauma were TM retraction and redness (9 percent) and TM rupture (4 percent). Many patients (40 percent) with middle ear barotrauma had a normal otoscopic examination.

DIFFERENTIAL DIAGNOSIS

The differential diagnosis of ear pain accompanied by hearing loss and disequilibrium includes acute otitis media, otitis media with effusion, trauma, foreign body, and cerumen impaction. These etiologies can usually be distinguished with a careful history and otoscopic examination. Symptoms that occur in the appropriate context (ie, changes in atmospheric pressure) make ear barotrauma much more likely.

The differential diagnosis of hearing loss, tinnitus, and/or vertigo in a diver includes inner ear decompression sickness, which can occur during diving ascent when gas bubbles form in the inner ear due to rapidly decreasing environmental pressure. Decompression sickness usually involves multiple organ systems, and symptoms typically include muscle and joint pain as well as fatigue. If only inner ear symptoms are present, time of onset can be useful to distinguish the two diagnoses. Inner ear barotrauma typically occurs during descent, whereas symptoms of decompression sickness typically begin after surfacing. Otoscopic examination in decompression sickness is usually normal [3]. (See "Complications of SCUBA diving", section on 'Decompression sickness'.)

The differential of hearing loss and vertigo are discussed in detail elsewhere. (See "Etiology of hearing loss in adults" and "Causes of vertigo".)

DIAGNOSTIC EVALUATION

Establishing the diagnosis — Ear barotrauma is a clinical diagnosis based on a consistent clinical history and compatible physical examination findings. Symptoms of ear pressure, pain, hearing loss, tinnitus, and/or vertigo occurring in the setting of a change in surrounding air pressure (eg, during flying or diving) suggest the diagnosis. Physical examination findings of ear injury (eg, tympanic membrane [TM] swelling, bleeding, or perforation; middle ear effusion or bleeding) confirm the diagnosis. (See 'Clinical manifestations' above.)

A normal examination does not exclude the diagnosis of ear barotrauma. In such cases, we make the diagnosis based on clinical history after excluding other causes of similar symptoms (See 'Differential diagnosis' above.)

Evaluating for inner ear injury — Patients with ear barotrauma and inner ear injury are at risk for permanent symptoms; it is important to identify and expedite ear, nose, and throat (ENT) evaluation for these patients.

Symptoms concerning for inner ear injury include:

●Sensorineural hearing loss – In patients with hearing loss, Rinne and Weber testing should be performed to distinguish conductive from sensorineural hearing loss (figure 3 and table 1). Sensorineural hearing loss occurs from injury to the inner ear, while conductive hearing loss is typically more consistent with middle ear injury. Patients with suspected sensorineural hearing loss should have audiometry to confirm the diagnosis and evaluate the degree of hearing loss.

●Persistent vertigo – Vertigo due to inner ear injury is often accompanied by nystagmus. It can worsen with positive pressure applied to the ear or with Valsalva maneuvers, due to increased perilymph leakage through the perforated round and oval membranes.

Tinnitus is another symptom frequently reported by patients with inner ear injury. However, tinnitus is not specific for inner ear barotrauma; it can be seen with sensorineural or conductive hearing loss, and even from barotrauma without any change in hearing. Tinnitus does not usually warrant urgent ENT evaluation in the absence of sensorineural hearing loss or vertigo.

MANAGEMENT

Indications for urgent ENT referral

Inner ear injury suspected — Patients with vertigo, sensorineural hearing loss, and/or nystagmus may have inner ear injury and should be referred urgently to an ear, nose, and throat (ENT) specialist for evaluation and treatment. (See 'Evaluating for inner ear injury' above.).

Depending on the severity of injury, additional testing may include audiogram, vestibular testing, and/or computed tomography (CT) or magnetic resonance imaging (MRI) imaging. ENT-directed management may include medication and/or surgery. Hyperbaric oxygen treatment may be warranted if there is a concern for inner ear decompression sickness. (See "Complications of SCUBA diving", section on 'Decompression sickness'.)

In most cases, initial management is conservative and typically includes bed rest for 7 to 10 days with head elevation; this helps avoid increases in cerebrospinal fluid pressure and decreases the leakage of perilymph [9]. Surgery, including tympanotomy and patching of the round or oval window, is usually only necessary if symptoms deteriorate or persist beyond the initial observation period.

Sensorineural hearing loss from a perilymphatic fistula may be permanent even with early intervention. (See "Sudden sensorineural hearing loss in adults".)

Dizziness and tinnitus usually resolve, but resolution may take weeks to months in severe cases.

Blast injury — Patients with ear barotrauma as a result of blast injury warrant urgent ENT evaluation. These patients may also have ossicular disruption from skull fractures or contamination of the middle ear with debris from penetrating objects such as metal, wood, water, or dirt. Surgery is necessary in up to half of tympanic membrane (TM) perforations associated with blast injury [15,16].

General conservative management — Patients without indications for urgent ENT referral as noted above can be managed conservatively.

Patient counseling — We reassure patients that injuries due to ear barotrauma, including edema and/or hemorrhage of the TM, TM rupture, and serous or hemorrhagic otitis, heal with time. We advise patients with TM perforation to keep the ear dry to decrease the risk of infection.

Most mild injuries clear within hours as the middle ear pressure equalizes with the outside world. Swelling of the TM, fluid or blood accumulation in the middle ear, or bleeding into the TM can take days to weeks to resolve. Small TM perforations typically heal within weeks if normal Eustachian tube function is restored. Mild imbalance usually clears as the underlying ear blockage resolves.

Supportive treatment — We do not routinely recommend any medical interventions to patients with ear barotrauma; there is no evidence that any interventions expedite time to recovery. We manage specific situations as follows:

●Pain – We offer acetaminophen and/or nonsteroidal anti-inflammatory drugs (NSAIDs) for pain relief as necessary.

●Eustachian tube dysfunction – For patients with an obvious cause of underlying Eustachian tube dysfunction, we tailor the treatment approach to the cause. For example, we offer decongestants (either systemic or intranasal) and intranasal glucocorticoids for patients with rhinosinusitis. We offer antihistamines and intranasal glucocorticoids for patients with allergic rhinitis. In the absence of Eustachian tube dysfunction, there is no clear treatment role for these agents. (See "Eustachian tube dysfunction", section on 'Medical management'.)

●Contamination of middle ear and/or ear infection – We reserve antibiotics for patients who have TM rupture with contamination of the middle ear, and those with clear evidence of infection (eg, TM erythema or purulent drainage). For patients with a contaminated middle ear but without other signs of infection, topical antibiotics (eg, ofloxacin otic drops, five drops twice daily in the affected ear for three to five days) are appropriate. Patients who have clear signs of infection warrant systemic antibiotics. (See "Acute otitis media in adults".)

We generally do not prescribe oral glucocorticoids due to lack of evidence of long-term benefit and potential for adverse effect.

Surgical treatment for selected patients — Surgical treatment may be necessary for patients with persistent symptoms of serous otitis media or vertigo and for those with a nonhealing TM perforation.

●Persistent symptoms – Patients with persistent middle ear symptoms should be referred for ENT evaluation. While there is no firm timeline for this, in our experience, most patients experience symptom improvement within one to two weeks and symptom resolution within four to six weeks. Patients whose symptoms are persistent beyond these general timeframes may benefit from referral. In some cases, fluid from the middle ear can be drained to restore hearing. Myringotomy (incision in the TM) can also be used as treatment for ear barotrauma; a tympanostomy tube may be placed to keep the hole patent while the injury heals.

●Nonhealing TM perforation – Most TM perforations, particularly those involving less than 25 percent of the total TM area, heal spontaneously within four weeks. TM perforations that have not healed within four weeks warrant ENT referral for consideration of tympanoplasty.

Return to activity — We advise patients with inner ear injury due to barotrauma to avoid diving for six months and to avoid airplane travel for a minimum of two weeks. The duration to avoid diving is longer due to higher potential pressure changes and increased likelihood of injury compared with flying. While there is no high-quality evidence to inform how long patients should avoid activities associated with pressure change, we use these general timeframes to reduce the risk of reinjury during healing.

PREVENTION

General strategies for all patients

Activity avoidance — The main activities associated with ear barotrauma include flying, diving, and undergoing hyperbaric oxygen therapy. The best prevention of barotrauma is avoiding these activities when possible, particularly at times of increased susceptibility (eg, in the setting of upper respiratory tract infection or environmental allergy exacerbation) [4,26].

Treatment of Eustachian tube dysfunction — If activity cannot be avoided during periods of obstructive Eustachian tube dysfunction, treating the underlying cause may attenuate the risk of barotrauma. Treatment of various forms of Eustachian tube dysfunction is discussed elsewhere. (See "Eustachian tube dysfunction" and "Eustachian tube dysfunction", section on 'Obstructive dysfunction'.)

Maneuvers to equalize pressure — We instruct patients to perform maneuvers to help equilibrate pressure in the middle ear during activity. Performing these maneuvers frequently can prevent large pressure differences from forming and reduce the risk of injury. While evidence regarding the efficacy of these maneuvers is limited [27], we generally favor these as an initial preventative measure due to the ease of performing them and the minimal risk of adverse effects.

●Swallowing and yawning are simple maneuvers to open the Eustachian tube and allow air pressure to equilibrate. To encourage frequent swallowing, chewing gum or sucking on hard candies helps for adults and older children; nursing or sucking on a bottle or pacifier helps for infants.

●Valsalva maneuvers generate positive pressure in the nose and nasopharynx to overcome the Eustachian tube barrier and force air into the middle ear. This is commonly done by pinching the nostrils and gently blowing out through the nose while keeping the mouth closed.

There are several other specific techniques that can be used to equilibrate pressure in the middle ear (table 2). Commercial autoinflation devices may offer some benefit for individuals who have difficulty with these maneuvers (eg, young children) [28], although we do not routinely use these due to variable quality.

Additional strategies for selected patients

Decongestants for adults with prior barotrauma — For adults with a history of ear barotrauma and those with active congestion (eg, due to upper respiratory infection or allergies) who are planning an activity associated with barotrauma, we suggest oral or intranasal decongestants prior to the activity to reduce the risk of recurrence. Preactivity decongestants are not routinely used in children, as a benefit has not been shown in this population and they are at increased risk of adverse effects [29].

●In adults who are able to tolerate oral decongestants, we suggest pseudoephedrine 30 minutes prior to activity. Several studies have shown a reduction in flight- and diving-related barotrauma with pseudoephedrine [30-33]. As an example, in a randomized trial of 190 adults with a history of recurrent ear pain during air travel, pseudoephedrine prior to a flight decreased the rate of recurrent ear discomfort by approximately half compared with placebo (32 versus 62 percent) [33]. Mild drowsiness was the most commonly reported adverse effect.

●In adults unable to tolerate oral decongestants, we suggest intranasal oxymetazoline 30 minutes prior to the activity. The effectiveness of intranasal decongestants is uncertain. One study found improvement in flight-related barotrauma symptoms with oxymetazoline [30]; another did not find improvement in hyperbaric oxygen therapy-associated barotrauma with oxymetazoline and fluticasone pretreatment [34].

Surgery in severe situations — For patients with recurrent barotrauma despite other conservative preventive measures, surgery may be an option.

For patients undergoing hyperbaric oxygen therapy and those who have poor Eustachian tube function and must fly frequently, surgical placement of ventilation tubes can prevent barotrauma by eliminating the pressure differential between the middle ear and the outside world [35]. (See "Eustachian tube dysfunction", section on 'Surgical management if symptoms persist despite medical therapy'.)

However, myringotomies, with or without tubes, are not appropriate for the prevention of diving injuries. They open the middle ear up to fluid and infection from water that can pass into the middle ear.

Another option for severe Eustachian tube dysfunction is balloon dilatation of the Eustachian tube [36-41]. In a limited case series, it was used successfully to prevent diving-related ear barotrauma [42]. Several studies have shown success in maintaining adequate Eustachian tube function after balloon dilation [43-45]. (See "Eustachian tube dysfunction", section on 'Surgical management if symptoms persist despite medical therapy'.)

Methods without benefit — We do not recommend earplugs or moist heat to the ear to prevent barotrauma; while these methods are commonly used, there is no clear evidence that they provide benefit.

●Ear plugs – Earplugs designed to slow down the pressure changes with flying are widely available. Although these plugs allow more time to equalize the pressure change, they do not eliminate the need to equilibrate the pressure changes, and their benefit has not been demonstrated [46]. Such earplugs cannot be used with diving since equilibration of air pressure in the external ear canal blocked by earplugs cannot easily occur underwater.

●Moist heat to the ear – While it is common practice in aviation to apply moist heat to the ear when passengers are complaining of ear pain, this has not been shown to prevent barotrauma [47] and has led to occasional burn injuries.

INFORMATION FOR PATIENTS — 

UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5^th to 6^th grade reading level, and they answer the four or five key questions a patient might have about a given condition. These articles are best for patients who want a general overview and who prefer short, easy-to-read materials. Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed. These articles are written at the 10^th to 12^th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon.

Here are the patient education articles that are relevant to this topic. We encourage you to print or e-mail these topics to your patients. (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.)

●Basics topics (see "Patient education: Eustachian tube problems (The Basics)")

SUMMARY AND RECOMMENDATIONS

●Pathogenesis – Ear barotrauma occurs when differences in pressure between the middle ear and the surrounding environment distort the tympanic membrane (TM), which can progress to rupture. In severe cases, the round or oval membranes separating the inner ear can rupture, leading to a perilymphatic fistula. Barotrauma is more likely when the Eustachian tube, which typically opens during yawning or swallowing to equilibrate pressure difference, does not function properly. (See 'Etiology and pathogenesis' above.)

●Common mechanisms of injury – The most common cause of ear barotrauma is air travel. Diving, use of decompression or hyperbaric oxygen chambers, and blast injuries are other common etiologies. (See 'Common mechanisms of injury' above.)

●Clinical manifestations and diagnosis – The diagnosis of ear barotrauma is clinical and suspected in patients with ear pressure, pain, hearing loss, vertigo, and/or tinnitus during or following a change in ambient pressure. Confirmatory exam findings include TM swelling, bleeding into the TM (picture 1), middle ear effusion, and/or TM perforation. Patients should be assessed for symptoms of inner ear injury, including sensorineural hearing loss and vertigo. (See 'Clinical manifestations' above and 'Diagnostic evaluation' above.)

●Management – Most ear barotrauma resolves with conservative management.

•Indications for urgent ear, nose, and throat (ENT) evaluation – Patients with symptoms of inner ear injury (vertigo, sensorineural hearing loss, or nystagmus) and those with barotrauma due to blast injury are at risk for permanent symptoms and should be referred urgently for ENT evaluation. Surgery may be needed for serious injuries such as ossicular disruption or perilymphatic fistula. (See 'Indications for urgent ENT referral' above.)

•General conservative management – Most barotrauma injuries heal with time; there are no specific therapies that have been shown to shorten the time to symptom resolution. Analgesics can be used as needed. The use of decongestants and antibiotics is limited to managing underlying abnormalities or complications of barotrauma. (See 'General conservative management' above.)

●Prevention – To prevent ear barotrauma, we advise avoiding activities associated with pressure change when possible, particularly when congested. We also identify and treat underlying Eustachian tube dysfunction. In addition, we instruct patients on maneuvers that can help equilibrate ear pressure during activity, including swallowing and Valsalva maneuvers for adults and older children, and nursing or sucking on a bottle or pacifier for infants. (See 'General strategies for all patients' above.)

For adults with a history of ear barotrauma planning for an activity associated with pressure change (eg air travel, diving), we suggest an oral decongestant rather than a topical decongestant or no treatment to prevent recurrence (Grade 2B). We use pseudoephedrine 30 minutes prior to the activity. (See 'Decongestants for adults with prior barotrauma' above.)

For patients with recurrent trauma, severe Eustachian tube dysfunction, and inability to avoid activities associated with barotrauma, surgical options for prevention include myringotomy and balloon dilatation of the Eustachian tube. (See 'Surgery in severe situations' above.).