Barotrauma: what it is, causes, symptoms and treatment

general information

Barotrauma - This is tissue damage as a result of changes in pressure and expansion or contraction of gas in the organs of the human body. Potential sites of involvement are the lungs, gastrointestinal tract, masked face, ears, eyes, or paranasal sinuses.

Symptoms vary - breathing disorders or chest pain (lung barotrauma), eye hemorrhage (barotrauma face), systemic dizziness or ear pain (barotrauma of the ear), or pain in the face or nosebleeds (barotrauma sinuses).

The risk of organ damage is highest from the surface to a depth of 10 meters.

For the prevention of barotrauma, it is recommended to ascend slowly, without holding your breath (pulmonary barotrauma), exhale air through the nose inside the mask (facial barotrauma) and yawn or swallow with pinched nostrils and apply a nasal decongestant (ear barotrauma and sinuses).

The increased external pressure is evenly transmitted to the blood and body tissues; however, they are not compressed, since they consist predominantly of liquid. Accordingly, the feet do not feel the increased water pressure. However, gases (such as air in the lungs, sinuses, middle ear, or inside a mask or glasses) contract or expand as the external pressure increases or decreases. This expansion and contraction causes pain and can damage tissues.

Barotrauma most often affects the ears. The greatest danger to the body is pulmonary barotrauma. The risk of barotrauma is increased by conditions that prevent the free movement of air between cavities, such as sinus congestion or blockages in the Eustachian tube (the canal that connects the middle ear to nasopharynx).

Pulmonary barotrauma

Air under high pressure is compressed, so at depth, each breath contains many more air molecules than on the surface. So, at a depth of 10 m (at a pressure of 2 absolute atmospheres), each breath contains twice as much molecules than on the surface (accordingly, the air cylinder of the scuba is emptied twice faster). When the pressure drops, the air expands and expands. Therefore, if a diver fills the lungs with compressed air at a depth of 10 m and floats, holding their breath, the volume of air in the lungs will double and inflate them.

By inflating the lungs, air tears open the alveoli in and out of them. Once in the space between the lungs and the chest wall, this air continues to expand and causes the lungs to collapse (pneumothorax). In addition, air can be forced from the lungs into the tissue around the heart (pneumomediastinum), under the skin of the neck and upper chest (subcutaneous emphysema) or into blood vessels (air embolism - Rare Types of Emboli). Once in the arteries, air is usually carried throughout the body (arterial gas embolism) and can block blood circulation.

The most common cause of pulmonary barotrauma is breath holding during ascent, usually due to the fact that the scuba tanks have run out of air. Panicked, the scuba diver may forget to breathe out as the air expands in the lungs during the ascent. Air embolism can occur already at a meter depth if a person breathing compressed air quickly floats up, holding their breath. Pulmonary barotrauma even occurs in the pool if the swimmer inhales the bottom air (for example, from an inverted bucket) and does not exhale it during the ascent.

Symptoms of barotrauma

Barotrauma symptoms usually occur at the surface of the water during a dive or ascent. The nature of the symptoms depends on the organ affected. Some types of barotrauma, other than pulmonary, caused by pressure drops, are called crimps.

Pulmonary barotrauma

Pneumothorax and pneumomediastinum cause chest pain and shortness of breath. When lung tissue is damaged, some people spit up blood or blow bloody foam at the mouth. Air entering the tissues (subcutaneous emphysema) of the neck can pinch the nerves of the vocal cords and lead to hoarseness or distorted voice. When touching the areas of the skin affected by subcutaneous emphysema, a characteristic crackling is heard.

Facial barotrauma (mask crimping)

If the emerging scuba diver is unable to equalize the pressure inside the mask with the water pressure, then the relatively low pressure inside the mask essentially turns it into a large medical jar placed on eyes and face. The difference in pressure inside and outside the mask causes the blood vessels located near the surface of the eyes and face to expand, secrete fluid, and then burst and bleed. The eyes are bloodshot, but the vision does not deteriorate. In rare cases, crimping can cause bleeding behind the eyeball, causing loss of vision. Hemorrhage from the blood vessels of the face is usually accompanied by bruising.

Ear barotrauma

If, during descent, the pressure inside the middle ear becomes lower than the water pressure, a painful protrusion of the eardrum inwards occurs. When the pressure difference becomes large enough, the eardrum bursts and a stream of cold water rushes into the middle ear, causing systemic dizziness (very severe dizziness with a spinning sensation), disorientation, nausea, and in some cases - vomiting.

These symptoms are signs of ear barotrauma and can lead to drowning of the diver. When the water in the ear reaches body temperature, the systemic vertigo subsides. A ruptured tympanic membrane impairs hearing, and after a few hours or days can lead to the development of a very painful middle ear infection, accompanied by discharge. Barotrauma can also damage the inner ear and cause sudden hearing loss. tinnitus (tinnitus) and vertigo.

Sinus barotrauma

The effect of pressure difference on the sinuses (air-filled cavities in the bones around the nose) is similar to the mechanism of ear barotrauma. Sinus barotrauma is accompanied by pain in the head and face on immersion and a feeling of numbness in the face or nasal congestion or nosebleeds on ascent.

Barotrauma of teeth

Pressure in air pockets at the roots of teeth or around fillings can cause toothaches or damage teeth.

Barotrauma of the eye

Small air bubbles can form between the rigid contact lens and the eye. These bubbles can damage the eye and cause irritation, loss of vision, and halos around light sources.

Barotrauma of the gastrointestinal tract

Improper breathing technique through the scuba regulator or unsuccessful attempt to equalize the pressure in the ears and sinuses may cause the scuba diver to swallow small amounts of air. On ascent, this air expands, causing a feeling of fullness in the stomach, cramps, pain, belching, and flatulence. These symptoms usually go away on their own. In rare cases, rupture of the stomach or intestines can occur, accompanied by severe abdominal pain and severe illness.

Diagnostics

Diagnosis of the condition is mainly based on the nature of the symptoms and their relationship to diving. Imaging tests may be required depending on symptoms. So, with pulmonary barotrauma, a chest x-ray is usually done. For ear or eye barotrauma, hearing or vision is tested.

Prophylaxis

The pressure in the lungs and in the airway is automatically equalized with the external pressure when compressed air is applied to the depth, either through a diving helmet or from a cylinder. This compressed air also normalizes the pressure in the sinuses if they are not narrowed, for example, as a result of allergic inflammation or an upper respiratory infection.

The pressure inside the mask is normalized by exhaling into the mask through the nose. The pressure inside the middle ear evens out when yawning or swallowing with the nostrils pinched - at this point, the channel between the middle ear and the nasopharynx (Eustachian tube) opens.

Ear plugs or fitted wetsuit hood creates a closed space between earplugs / adjacent to ear tissue and eardrum and do not allow the pressure of the person in this area to equalize air. The pressure inside the swim goggles is also impossible to equalize. Accordingly, no earplugs or swimming goggles should be used while diving. Fitted wetsuit hoods must be sufficiently breathable so as not to block the outer ear.

Divers with nasal congestion may take a decongestant (such as pseudoephedrine tablets) before diving. Relief of nasal congestion helps to equalize the pressure in the ears and sinuses and is the prevention of barotrauma of the sinuses and ears.

In order to avoid pulmonary barotrauma, it is necessary to exhale during the ascent all the air received at a depth - even at the depth of the pool.

Treatment of barotrauma

Some cases of pneumothorax require specialized treatment, such as inserting a plastic tube into the chest wall to evacuate air so that the lungs can expand. Treatment for pneumomediastinum and subcutaneous emphysema is usually bed rest and supplemental oxygen.

Ear and sinus barotrauma is treated with nasal decongestants (eg, oxymetazoline nasal spray) or oral decongestants. In some cases, when the healing process is extremely slow, the victim may be prescribed corticosteroids in tablets or in the form of a nasal spray.

A ruptured eardrum usually heals on its own, and treatment for a middle ear infection requires oral antibiotics or ear drops. A ruptured canal between the middle and inner ear may require urgent surgery to avoid permanent damage.

A ruptured stomach or intestine requires surgery.