[Physiopathologic consequences of underwater diving and medical management of divers]

Underwater diving is a very closely medically managed activity. Performing it, the human organism is under the physical laws of pressure and following consequences. The expiratory flows are significatively reduced, enhancing the risk of alveolar hypoventilation at exertion, the central nervous system is the privileged target during inopportune tissue degassing related accidents (leaving 20% of sequellae), barotraumatic injuries threaten middle and inner ear or lung (pulmonary barotrauma is the most severe accident), the toxicity of gas under pressure (i.e. oxygen, nitrogen) exposes to specific risks of loss of consciousness. Lastly, the adaptative mechanisms to immersion can be overflown, leading to pulmonary oedema. Facing these constraints, the practitioner's role begins just before the diver's activity starts by looking for contraindications to diving. It continues during tuition time by teaching him the physiopathology of accidents, their prevention and first cares. Finally, in case of accident, a specialized medical team acts in diagnosis and treatment. From these points of view, diving medicine is a multispecialty medical matter.