Diving Illnesses, Symptoms & Emergency Response

This rough guide is designed to give you a brief overview of SOME of the most common diving illnesses, how to recognise SOME of their symptoms and suggests how to respond in such a situation. Please be aware that no responsibility will be taken by DCU-SAC for any injury etc. caused by applying any of the proceedures on this page. This pages content may be false, or out of date.

This is not an exhaustive guide so if you are not sure about anything, ask your instructors or one of the more experienced members of the club for help.

Decompression Illness (DCI).

Decompression illness is a very aka the bends, serious condition that all scuba diver must be aware of. Decompression is caused by a reduction in ambient pressure, such as that which occurs when a diver ascends from depth, for example an ascent from 20metres (3 bar) to the surface (1 bar). Body tissues absorb gases at different rates, depending on blood supply and the type of tissue. Those, which absorb nitrogen quickly such as the heart, lungs and liver, also release the nitrogen quickly. Tissues that absorb nitrogen slowly release it slowly e.g. bones and fat. Therefore, on ascent, nitrogen at high pressure would remain in the slow tissue. In extreme cases bubbles could also form in the blood stream. It is the presence of these nitrogen bubbles within the body tissue that causes decompression sickness or The Bends.

Symptoms of decompression illness can range from mild to severe and include

• Discolouration or itching of the skin.
• Joint pains, elbows, shoulders or knees.
• Numbness or weakness.
• Poor sense of balance.
• Paralysis in the arms and legs.

The Emergency Response for decompression sickness involves treating the casualty with 100% Oxygen followed by removal to a recompression chamber.

Decompression illness can be avoided by taking the following precautions

• Always dive within the limits of the dive tables or dive computer.
• Always obey the correct ascent rate (10meters/min for CFT divers).
• Always dive the deeper dive of the day first.
• Always Plan your dive and dive your plan.
• Ensure all safety stops are obeyed unless previously specified.
• Never dive with a hangover.

Burst Lung.

A burst lung is an extremely serious diving illness however it is easily avoided.
The effect of a burst lung is due to Boyles law which states "At a constant temperature the pressure of a fixed mass of gas is inversely proportional to its volume".
In simple terms, this means that if the pressure acting on a gas is released the gas will expand increasing its volume. The proportion of expansion relates to the amount of pressure released so that if the pressure is halved, the volume will double.
If a scuba diver ascends towards the surface, the expansion effects of Boyle's Law on the air in the lungs, unless adequately exhaled, can cause the tissues of the lungs to rupture and the air within them to escape into the bloodstream or chest cavity. This is extremely dangerous and often fatal so Never hold your breath while using scuba equipment!

If a diver at 10 meters (pressure of 2 BAR) ascends to the surface, holding his/her breath, the volume of the lungs, under Boyle's Law, should double in size. Unfortunately the tissues of the lungs are not elastic and can not expand more than a tiny fraction beyond their original volume. If the maximum expansion of the lungs is exceeded, the tissues of the alveoli and other parts of the lungs will tear, allowing air to escape into the bloodstream and chest cavity. Therefore, ill say it again, Never Ever hold your breath while using scuba equipment, just breath normally!

Symptoms of a burst lung include

• Bloody, frothy sputum at the mouth.
• Possible chest pain and coughing.
• Staggering.
• Pain on one side of the chest.
• Confusion or difficulty with vision.
• Paralysis or weakness of limbs.
• Convulsions.
• Cessation of breathing.
• Cyanosis.
• Collapse and unconsciousness.
• Death.

The treatment of a burst lung requires immediate diagnosis and prompt action. The following procedure should be followed:

• Recover the victim from the water.
• Administer 100% Oxygen (O2), in order to assist the oxygenation of blood and tissues.
• Immediate removal of the victim to a recompression chamber is essential. Prompt recompression is vital to minimize the size of the bubbles and allow blood to flow freely.

Hypothermia.

Hypothermia is a very serious condition that poses a threat to all divers and mariners alike. The risk of hypothermia however can be greatly reduced by taking the appropriate precautions.
The normal body temperature is about 36.9oC. Hypothermia occurs when the core body temperature is lowered below 35oC. A change of just 2oC, thats all it takes.

Hypothermia may be caused by any type of exposure to the cold, wind and water being contributing factors. So prolonged immersion in cold water is especially dangerous, and hypothermia can occur in just a few minutes in these conditions.
Effects of hypothermia include uncontrollable shivering, difficulty in speaking, loss of all dexterity, jerky or erratic movements, inability to reason, unconsciousness and possibly death.

• Remove the person from the cause e.g. Water.
• Warm the person up using coats, hats or any other dry materials (Space Blanket).
• If travelling on a boat make sure the victim is protected form the elements.
• Warm the victim with hot drinks if available, preferably soup. Do Not Give Tea, Coffee or any other stimulant.
• Only remove wetsuit if a dry change of clothes is available.

Shivering is the first serious sign of Hypothermia, if you ever start shivering tell someone immediately, seak shelter and warmth, ask for help.

• When travelling on a boat always bring a waterproof coat and warm hat.
• If during a dive you begin to feel cold inform your buddy and head towards the surface.
• Avoid standing around in a cold wetsuit after a dive.
• Bring a warm change of clothes for after the dive.
• Avoid wasting energy by over exertion.
• Allow time for acclimatisation to cold.

Disclaimer: Advice, proceedures and information on this page may be false, misleading or out of date. No responsibility is taken by DCU-SAC or its members for any eventuality related to any use of the information contained in this document.