Barotrauma

When a diver descends, the ambient pressure increases, causing air-filled spaces within the body to compress. When ascending, the ambient pressure decreases, causing these spaces to expand. Barotrauma occurs when the pressure inside these spaces cannot equalise with the external pressure, leading to a pressure differential that damages surrounding tissues. For example, during descent, if a diver cannot add air to their middle ear, the external pressure causes the eardrum to bulge inward, potentially leading to pain and rupture. Conversely, during ascent, if trapped air cannot escape from a space (e.g., lungs), the expanding air can cause tissue damage.

Several types of barotrauma are recognised. Ear barotrauma (otitic barotrauma), the most common, ranges from mild discomfort to eardrum rupture or inner ear damage. Sinus barotrauma affects the air-filled sinuses in the face and skull, causing pain, nosebleeds, or headache. Pulmonary barotrauma, also known as lung overexpansion injury, is the most serious, occurring when air is trapped in the lungs during ascent, leading to lung tissue rupture and potentially pneumothorax (collapsed lung), mediastinal emphysema, or arterial gas embolism (AGE).

Other forms include dental barotrauma (barodontalgia), where air trapped in dental fillings or cavities expands or contracts, causing pain; facial barotrauma, caused by a poorly fitting mask that creates a vacuum on the face (mask squeeze); and less commonly, gastrointestinal barotrauma from expanding gases in the digestive tract. Prevention hinges on effective and timely equalisation, avoiding rapid pressure changes, and not diving while congested.

For liveaboard divers, preventing barotrauma is paramount to ensuring a continuous and enjoyable diving experience. The typical liveaboard itinerary involves multiple dives per day over several days, often in diverse and sometimes remote locations. An episode of barotrauma, even a mild one, can force a diver to miss subsequent dives or, in severe cases, require evacuation and medical attention, thereby disrupting the entire trip for the individual and potentially others.

To mitigate the risk, divers should proactively manage their ear and sinus health. This includes ensuring they are well-rested and hydrated, and avoiding diving if experiencing symptoms of a cold, allergies, or sinus congestion. Many experienced liveaboard divers carry nasal decongestants (used cautiously and as per medical advice) or saline nasal sprays to aid in equalisation, especially during multiple dive days.

Liveaboard crew are trained to assist divers with safe diving practices, including emphasising slow descents and proper equalisation techniques during dive briefings. Should barotrauma occur, the crew can provide initial first aid and assist with communication to medical facilities. However, the ultimate responsibility for prevention lies with the individual diver, making awareness and proactive measures key to a successful liveaboard adventure.

Myth: Barotrauma only affects the ears. Fact: While ear barotrauma is the most common form, this injury can affect any air-filled space in the body that cannot equalise pressure. This includes sinuses, lungs (pulmonary barotrauma), teeth (barodontalgia), and even a poorly fitting mask can cause facial barotrauma.

Myth: If you can equalise on land, you won't get barotrauma underwater. Fact: Equalising on land is different from equalising under pressure. The increased ambient pressure underwater makes it more challenging to open Eustachian tubes. Congestion, even mild, can block passages that were clear on land. Effective equalisation requires conscious effort and consistency throughout the descent.

Myth: Forceful equalisation is the best way to prevent barotrauma. Fact: Forceful equalisation, such as aggressive Valsalva manoeuvres, can actually cause barotrauma, particularly to the middle ear. Gentle, early, and frequent equalisation techniques (e.g., swallowing, jaw wiggles, Frenzel manoeuvre) are safer and more effective, allowing air to enter the Eustachian tubes without excessive pressure.

Myth: Barotrauma is the same as Decompression Sickness (DCS). Fact: These are distinct conditions. Barotrauma results from pressure differences in air-filled spaces, causing mechanical tissue damage, typically felt during or immediately after the pressure change. DCS is caused by nitrogen bubbles forming in tissues due to rapid pressure reduction after saturation, with symptoms often appearing minutes to hours after surfacing.