BACKGROUND: Capillary leak syndrome is a rare type of decompression sickness (DCS) that may be responsible for hypovolemic shock with edema.
METHODS: A 21-year-old amateur diver suffered from an inner ear DCS following air diving to 96msw. He presented subsequent deterioration with hypovolemia and facial edema secondary to capillary leak syndrome.
CONCLUSIONS: In DCS, bubbles formation alters the wall of blood vessels and activates complex biochemical mechanisms inducing extravascular protein leakage. The clinical expression of this syndrome is variable, ranging from simple hemoconcentration to hypovolemic shock. Close clinical-biological monitoring of patients with elevated hematocrit with or without hypoalbuminemia is advisable. Early vascular filling with albumin infusion may prevent the occurrence of hypovolemic shock and improve the prognosis.

Decompression sickness in underwater diving exposes the diver to a risk of clinical sequelae which require specific care. In the absence of sequelae or after clinical recovery, the question of diving again may be raised. As part of a secondary prevention approach, the hyperbaric practitioner measures the physical, psychological and social impact of re-exposure to pressure and the immersion of the patient-diver.

One of the reasons for the emergency use of a hyperbaric chamber concerns a diving-related accident. Decompression sickness is potentially serious; it requires urgent treatment and hyperbaric recompression. It is caused by the formation of nitrogen bubbles in the organism which appear during the diver\'s ascent and throughout his or her decompression.

The number of recreational scuba divers is steadily increasing. In its latest recommendations, the French Federation of Undersea Studies and Sports listed congenital heart disease as a formal and final contraindication to scuba diving. On the other hand, with the progress made in their management, the prognosis and quality of life of patients with congenital heart diseases have improved considerably, enabling them to engage in physical and sports endeavours, which are known to confer general health and psychological benefits. As a consequence, the ability of these patients to dive has become a regular and recurrent issue. We review the various types of scuba diving, the physical performance required for its practice, its effects on cardiovascular function and the elements that need to be considered before recommending whether it can be practiced safely at various levels of difficulty. Because of the diversity and broad heterogeneity of congenital heart diseases, a detailed evaluation of each patient\'s performance based on clinical criteria common to all congenital heart diseases is recommended.