Diving Medicine

Dr. Schochet’s interest in diving has led him to assisting young divers with asthma. He understands that divers with asthma are more prone to diving mishaps. This is why it is important for asthmatics to have their medication regimen evaluated and have physical exams prior to going on diving trips. Although he doesn’t treat diving illness, he is an advocate for preventing diving illness in young asthmatics.

Diving medicine, also called undersea and hyperbaric medicine (UHB), involves diagnosing and treating SCUBA diving illnesses and injuries to the respiratory system including decompression sickness, barotrauma, arterial gas embolism, and pneumothorax. Because SCUBA diving is such a rapidly growing sport, with diving certifications tripling worldwide in the last 20 years, the need for quality diving medicine has similarly increased. The ability to recognize, diagnose and treat diving injuries and illnesses is key to a prompt and successful recovery after a diving injury.

Common SCUBA-related illnesses or injuries include:

• Ear and sinus barotrauma
• Pulmonary barotrauma and pneumothorax
• Pulmonary edema
• Decompression illness (DCI): Includes decompression sickness and arterial gas embolism

Ear and Sinus Barotrauma

Ear and sinus barotrauma are common injuries for divers that can be debilitating. Barotrauma occurs when the body is unable to equalize pressure within a gas-filled area, such as the middle ear. Ambient pressure changes during ascent and descent, and the difference in pressure can result in damage to body tissues. Types of barotrauma include:

• Middle ear barotrauma, also known as middle ear squeeze: Occurs when the Eustachian tube does not equalize pressure in the middle ear, allowing volume to decrease. Most common injury for first time divers. Symptoms include ear pain, vertigo, and possible conductive hearing loss.
• Inner ear barotrauma: Often occurs in relation to middle ear barotrauma, by which the diver forcefully uses a Valsalva maneuver to equalize pressure in the middle ear. May also occur during rapid ascent. Symptoms can include ear ringing (tinnitus), vertigo, and hearing loss.
• Sinus barotrauma, also known as sinus squeeze: Occurs when nasal congestion prevents sinus pressure from equalizing during descent. Symptoms may present as facial pain, nosebleed, and increased pressure with further descent.

Depending on the type of barotrauma being experienced, treatment may involve:

• Decongestants and analgesics
• Bed rest
• Head elevation
• Avoiding strain
• Warm compresses
• Oral steroids or antibiotics

Pulmonary Barotrauma

Pulmonary barotrauma can occur when a diver holds his breath during ascent (when ambient pressure reduces). If the compressed air inside the lungs is not allowed to escape, gas inside the lungs can expand and rupture the alveoli (sacs inside the lungs which allow carbon dioxide and oxygen to move into the bloodstream). The air escaping from the alveoli enters the surrounding tissues and can cause:

• Mediastinal emphysema: Air forced into tissue around the trachea and heart.
• Subcutaneous emphysema: Air forced under the skin around the collarbone and neck.
• Pneumothorax: Collapsing of a lung due to the escaped air leaking into the chest cavity and placing pressure on the outside of the lungs.
• Spontaneous pneumothorax: Lung collapse which is usually caused by weak areas in the lungs is called blebs. 60% of divers who experience one episode of spontaneous pneumothorax are likely to have a recurrence.
• Arterial gas embolism (AGE): Condition, in which a trapped air bubble blocks the flow of blood, keeping oxygen from organs and tissues.

Certain medical conditions may put divers at risk for pulmonary barotrauma:

• Active asthma – wheezing due to bronchoconstriction
• Congestion
• Bronchitis
• Respiratory tract infections
• Permanent conditions which can be a factor in pulmonary barotrauma are:
• Persistent asthma
• Scarred lung tissue or abscesses
• Tumors
• Mucous obstructions from smoking
• Fibrosis
• Tuberculosis
• Blebs

Scuba Diving and Asthma

While approximately 4-7% of active divers have asthma, precautions should be taken when a diver is asthmatic. Pulmonary obstruction, hyperinflation, and air trapping, which can occur during an asthma attack, could place a diver at risk for pulmonary barotrauma. Recent studies, however, show that asthmatic divers who show normal lung function have little to no additional risk. A diver should not dive if experiencing asthmatic symptoms, such as:

• Difficulty breathing
• Wheezing
• Coughing
• Fever

If you have permanent lung damage from asthma or chronic emphysema, you should not scuba dive.

Pulmonary Edema of Diving

Pulmonary edema occurs when fluid accumulates in the lungs and impairs oxygen flow to the blood. Pulmonary edema is characterized by sudden shortness of breath, coughing, and a drowning feeling. When an occurrence happens during diving, it is called immersion pulmonary edema (IPE). IPE can happen to anyone and its exact cause is unknown. Possible causes include:

• Fluid shifting into the lungs due to water immersion
• Lung abnormalities
• Contaminants in the breathing air
• Excessive resistance in scuba regulator

Divers who experience IPE may cough up frothy, pink sputum. IPE can be treated with 100% oxygen and a diuretic medication, and in most cases, has no residual effects. Health should be normal before diving is resumed.

Decompression Illness (DCI)

Decompression illness can occur when the body is surrounded by a reduction in ambient pressure, such as when ascending from a dive. The two types of DCI are:

1. Decompression sickness (DCS): Bubbles form in blood and tissue, which causes local damage.
2. Arterial gas embolism (AGE): Results from bubbles entering the bloodstream and blocking blood flow, which can cause tissue damage.

Risk factors for DCI include:

• Rapid ascents: Divers stop at 5 meters below surface to decompress
• Deep, long dives
• Hard exercise at depth
• Cold water

1 Decompression Sickness (DCS)

Decompression sickness, which is also referred to as the bends or caisson disease, arises when inadequate decompression follows increased pressure exposure. A diver’s body absorbs nitrogen and other gases, which can form bubbles when pressure is reduced quickly. Mild cases of DCS involve bubbles near or in the joints and cause the pain associated with the bends. More severe cases occur when a large amount of bubbles enter the venous bloodstream causing complex reactions in the body. DCS can be categorized as Type I or Type II.

Type I DCS has no neurologic or systemic symptoms, but rather presents musculoskeletal symptoms, such as:

• Dull, throbbing joint pain (usually elbows or shoulders)
• Skin rash
• Pruritis (itchy skin)
• Skin marbling

Type II DCS typically involves the spinal cord or brain and affects neurologic, pulmonary, and vestibular systems. Symptoms include:

• Dizziness
• Weakness
• Numbness
• Abnormal gait
• Hypoesthesia (loss of sensation)

Inner ear decompression sickness (IEDCS) is a Type II DCS associated with saturation dives. IEDCS, also known as the staggers, may be a result of bubbles forming in the semicircular canals. Symptoms may present as:

• Acute vertigo
• Nausea and vomiting
• Tinnitus
• Hearing loss
• Nystagmus (involuntary eye movement)

Decompression sickness is not a common occurrence (2-3 times per 10,000 dives) and usually becomes evident within 1-6 hours of a dive. Treatment for DCS requires recompression therapy in a special recompression chamber as quickly as possible.

2 Arterial Gas Embolism (AGE)

Arterial gas embolism is a serious form of decompression illness in which the respiratory gases expand, typically during ascent. These gas bubbles enter the bloodstream and interrupt circulation. AGE can be caused by:

• Rapid or panicked ascent
• Holding breath during ascent
• Obstructive lung disease

Symptoms of AGE are:

• Dizziness
• Disorientation
• Blurred vision
• Decreased sensation
• Chest pain
• Bloody sputum
• Weakness or paralysis
• Convulsions
• Unconsciousness

Treatment for Decompression Illness (DCI):

Both AGE and DCS can present with only mild symptoms that may resolve on their own, however both forms of DCI can cause residual damage to vital organs. If you have been diving and experience symptoms of diving illness, you should see your doctor even if symptoms have subsided.

Severe diving accidents require recompressing divers in a recompression chamber. The goal of recompression therapy is to prevent both further and permanent injuries caused by DCI.

Decompression Illness Therapy Goals:

1. Raised atmospheric pressure to shrink the gas-phase (bubble) volume
2. Raised inspired PO2 to washout the inert gas, promote tissue oxygenation and reduce edema
3. Adequate treatment time
4. Adequate fluid management
5. Appropriate drug therapy

Dr. Schochet cautions parents on SCUBA diving lessons for children. If a child over the age of 10 is physically, mentally and emotionally able to handle the skills and understand the knowledge needed to scuba dive and wants to learn, he or she should be able to get certified. A good way to determine if your child is ready for scuba diving in open water is to enroll them in junior scuba diver course that comes with restrictions. The minimum age is 10 years old (in most areas). Student divers who are younger than 15 earn the PADI Junior Open Water Diver certification, which they may upgrade to PADI Open Water Diver certification upon reaching 15. 

For more information about evaluating and educating young divers with asthma please submit an online appointment request or contact the office of Dr. Peter Schochet and Dr. Hauw Lie.