Early Pulmonary Effects of Excursion Deep Diving With Closed-circuit Gas Recycling: SPIDD Study

Early Pulmonary Effects of Excursion Deep Diving With Closed-circuit Gas Recycling: SPIDD Study

Scuba diving with closed circuit gas rebreathers is currently booming. Initially developed for professional and military diving, this type of diving has become very successful in recreational activities.

The possibilities offered by this equipment are immense and reduce the constraints of exploration time and depth. More and more divers are seeking to reach depths previously considered unusual or inaccessible in recreational diving, beyond 100 meters. By pushing back these limits, the diver is exposed to new risks which should lead to a reflection on the means of prevention and treatment in case of incident.

The physiological repercussions of these deep dives are not well known. During daily deep excursions in the 90-120 meter zone, there is a significant reduction in vital capacity on leaving the dive, which persists and worsens the following day.

It seems necessary to confirm the importance of this impairment, never documented before, and to explore its mechanisms. A better knowledge of this respiratory impact could allow to improve the prevention and the preliminary evaluation of the medical aptitude of these divers.

Inclusion Criteria:

• Diver ≥ 18 years old
• Recreational rebreather diver with a recognised qualification (Mixed Gas CCR training or equivalent) and the necessary experience for this type of diving who has scheduled a dive in the 60 metre depth zone
• Diver using his/her own equipment, i.e. a closed circuit rebreather with back lungs meeting CE standards.
• Having a medical certificate of no contraindication to the practice of underwater activities < 1 year issued by an authorised doctor
• Having taken out personal insurance covering this type of activity
• Voluntary and having given his/her express, free and informed consent
• Affiliated to the Social Security

Exclusion Criteria:

• Diver refusal
• Known previous respiratory pathology
• Use of medication that may alter pulmonary and/or vascular function as well as inflammatory and haemostasis parameters
• Any temporary contraindication to the practice of scuba diving
• Patient under guardianship or trusteeship
• Immersion beyond 30 metres within 7 days or any scuba diving within the previous 48 hours.