Aerosinusitis, also called barosinusitis, sinus squeeze or sinus
barotrauma
Barotrauma is physical damage to body tissues caused by a difference in pressure between a gas space inside, or in contact with, the body and the surrounding gas or liquid. The initial damage is usually due to over-stretching the tissues in ...
is a painful
inflammation
Inflammation (from ) is part of the biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', '' ...
and sometimes bleeding of the
membrane
A membrane is a selective barrier; it allows some things to pass through but stops others. Such things may be molecules, ions, or other small particles. Membranes can be generally classified into synthetic membranes and biological membranes. Bi ...
of the
paranasal sinus
Paranasal sinuses are a group of four paired skeletal pneumaticity, air-filled spaces that surround the nasal cavity. The maxillary sinuses are located under the eyes; the frontal sinuses are above the eyes; the Ethmoid sinus, ethmoidal sinuses a ...
cavities, normally the
frontal sinus. It is caused by a difference in
air pressure
Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The Standard atmosphere (unit), standard atmosphere (symbol: atm) is a unit of pressure defined as , whi ...
s inside and outside the cavities.
Presentation
Typically, sinus
barotrauma
Barotrauma is physical damage to body tissues caused by a difference in pressure between a gas space inside, or in contact with, the body and the surrounding gas or liquid. The initial damage is usually due to over-stretching the tissues in ...
is preceded by an
upper respiratory tract infection
An upper respiratory tract infection (URTI) is an illness caused by an acute infection, which involves the upper respiratory tract, including the nose, sinuses, pharynx, larynx or trachea. This commonly includes nasal obstruction, sore throat ...
or
allergy
Allergies, also known as allergic diseases, are various conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include Allergic rhinitis, hay fever, Food allergy, food al ...
. The affected person has a sudden sharp facial pain or headache during descent, which increases as the aircraft approaches ground level. The pain can ultimately become disabling unless the ambient pressure is reversed.
The pressure difference causes the
mucosal lining of the sinuses to become swollen and submucosal bleeding follows with further difficulties ventilating the sinus, especially if the orifices are involved. Ultimately fluid or blood will fill the space.
In most cases of sinus barotrauma, localized pain to the frontal area is the predominant symptom. This is due to pain originating from the frontal sinus, it being above the brow bones. Less common is pain referred to the temporal, occipital, or retrobulbar region. Epistaxis or serosanguineous secretion from the nose may occur. Neurological symptoms may affect the adjacent fifth cranial nerve and especially the infraorbital nerve.
Pathology
The pathology of sinus barotrauma is directly related to
Boyle's law
Boyle's law, also referred to as the Boyle–Mariotte law or Mariotte's law (especially in France), is an empirical gas laws, gas law that describes the relationship between pressure and volume of a confined gas. Boyle's law has been stated as:
...
, which states that the volume of a gas is inversely proportional to the pressure on it, when temperature is constant (P1 × V1 = P2 × V2). Two types of acute barotrauma are observed: squeeze and reverse squeeze.
On ascent, the
air
An atmosphere () is a layer of gases that envelop an astronomical object, held in place by the gravity of the object. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A stellar atmosph ...
in the
paranasal sinus
Paranasal sinuses are a group of four paired skeletal pneumaticity, air-filled spaces that surround the nasal cavity. The maxillary sinuses are located under the eyes; the frontal sinuses are above the eyes; the Ethmoid sinus, ethmoidal sinuses a ...
es will expand according to Boyle's law, contracting during descent. Normally, the sinuses drain into the
nasal cavity
The nasal cavity is a large, air-filled space above and behind the nose in the middle of the face. The nasal septum divides the cavity into two cavities, also known as fossae. Each cavity is the continuation of one of the two nostrils. The nas ...
through small
ostia, which permit mucociliary clearance and ventilation that equilibrates pressure. However, when the opening is obstructed due to inflammation, polyps, mucosal thickening, anatomical abnormalities, or other lesions, pressure equilibration is impossible. Squeeze is produced on descent when trapped air in the sinuses contracts and produces negative pressure. The pressure differentials are directed to the center of the sinuses producing mucosal edema, transudation, and mucosal-or submucosal-
hematoma
A hematoma, also spelled haematoma, or blood suffusion is a localized bleeding outside of blood vessels, due to either disease or trauma including injury or surgery and may involve blood continuing to seep from broken capillaries. A hematoma is ...
, leading to further occlusion of the sinus ostium. The sinus will fill with fluid or
blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells.
Blood is com ...
unless the pressure differential is neutralized.
If the outlet is blocked during ascent, the situation is reversed and "reverse squeeze" appears.
Pressure inside the sinus increases, affecting the walls of the sinus and producing pain or epistaxis.
Location
The majority of episodes of sinus barotrauma occur in the frontal sinuses with pain localized over the frontal area. Possible explanations for this might be the relatively long and delicate
nasofrontal duct that connects the narrow frontal recess with the
frontal sinuses.
Barotrauma located in the
maxillary,
ethmoidal, or
sphenoid sinuses is observed less frequently and appears when the
ostia are blocked; the majority of cases are probably caused by an acute upper respiratory tract infection. The magnitude of the pressure difference needed to produce a barotrauma probably shows great individual variation and is related to the size of the sinus ostium and the rate of ambient pressure change. Due to this, even commercial flying may produce severe cases of barotraumas, although most of the cases are observed in high performance aircraft with lower pressurized cabins.
Diagnosis
Most cases occur in scuba
divers and
fliers, and is easily diagnosed when presented to physicians immediately after exposure.
[ On the other hand, the problem may remain undiagnosed when the history fails to relate the symptoms to exposure to environmental pressure changes or if the focus is on other etiologies.][
]
Grades
Weissman defined three grades of sinus barotraumas according to symptomatology.
* Grade I includes cases with mild transient sinus discomfort without changes visible on X-ray.
* Grade II is characterized by severe pain for up to 24 h, with some mucosal thickening on X-ray.
* Patients with grade III have severe pain lasting for more than 24 h and X-ray shows severe mucosal thickening or opacification of the affected sinus; epistaxis or subsequent sinusitis may be observed.
Treatment
Mild cases of barotrauma are readily treated by topical decongestants and painkillers.[ In severe cases or cases resistant to local treatment, functional endoscopic sinus surgery is indicated in order to re-establish drainage and ventilation of the sinuses. This treatment has shown good results in aviators who have recurrent sinus barotrauma. Computer-aided surgery has re-established the drainage of affected sinuses, especially with regard to the sphenoid sinuses. When the sphenoids were entered endoscopically, mucosal petechia and hematoma were clearly seen.
]
History
Sinus barotrauma or aerosinusitis has been known since the early development of aviation medicine
Aviation medicine, also called flight medicine or aerospace medicine, is a preventive or occupational medicine in which the patients/subjects are pilots, aircrews, or astronauts. The specialty strives to treat or prevent conditions to which air ...
. However, it was during World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
that the subject first received serious attention and the pathogenesis of the disease was understood to be due to exposure to high altitude flights. Rapid altitude changes with accompanying changes in ambient pressure exposed the aircrews to an increasing number of episodes of sinus barotrauma.
Referred pain
Pain is a distressing feeling often caused by intense or damaging Stimulus (physiology), stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sense, sensory and emotional experience associated with, or res ...
from barosinusitis to the maxilla
In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxil ...
consists about one-fifth of in-flight barodontalgia (i.e., pain
Pain is a distressing feeling often caused by intense or damaging Stimulus (physiology), stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sense, sensory and emotional experience associated with, or res ...
in the oral cavity
A mouth also referred to as the oral is the body orifice through which many animals ingest food and vocalize. The body cavity immediately behind the mouth opening, known as the oral cavity (or in Latin), is also the first part of the alime ...
caused by barometric pressure
Atmospheric pressure, also known as air pressure or barometric pressure (after the barometer), is the pressure within the atmosphere of Earth. The standard atmosphere (symbol: atm) is a unit of pressure defined as , which is equivalent to 1,013.2 ...
change) cases. Although the environment of fighter pilots produces the most stressful barometric changes, commercial flying has changed the picture of the disease.
See also
*
*
References
External links
{{Underwater diving, divmed
Aviation medicine
Effects of external causes
Underwater diving disorders