Barotrauma on descent in diving

On descent, barotrauma risk results from a decrease in gas volume as atmospheric pressure increases. Air-filled spaces such as the paranasal sinuses and the middle and inner ear need to maintain equilibrium. This is usually achieved through connections; the sinuses vent into the nasal cavity and the middle ears equalise with the throat via the Eustachian tubes. The ears and sinuses are at risk of damage if equalisation is reduced by conditions or behaviours, such as:

• upper respiratory tract congestion
• allergies
• nasal polyps
• a diver not equalising their ears during descent
• multiple dives in a short period; this increases mucosal oedema, which can reduce the ability to equalise.

Facemask ‘squeeze’ on descent can result in subconjunctival haemorrhage, lid oedema, and skin petechiae and bruising. Toothache, jaw pain and dislodged dental fillings may occur (‘dental squeeze’) on descent. Middle and inner ear damage can occur with divers reporting pain, pressure and hearing loss. Unilateral tympanic membrane rupture can result in vertigo, nausea and disorientation due to caloric stimulation of cold water in the middle ear. Paranasal sinus trauma can result in pain, headache and occasionally epistaxis.

Management of ear, dental and sinus barotrauma usually only requires reassurance and symptomatic management. Refer for otolaryngologist review if there is suspicion of inner ear damage. Divers should be reassessed before diving again for complete resolution of symptoms and to exclude new risk factors for barotrauma; see Medical fitness to return to diving.