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

Not Applicable
Completed
Conditions
Physiopathology
Interventions
Diagnostic Test: Pre and post dive examinations
Registration Number
NCT05775562
Lead Sponsor
University Hospital, Brest
Brief Summary

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.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
20
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.

Study & Design

Study Type
INTERVENTIONAL
Study Design
SINGLE_GROUP
Arm && Interventions
GroupInterventionDescription
Diving armPre and post dive examinationsThe standard arm involves all participants in the study. Subjects will perform pre-dive and post-dive examinations to characterize the respiratory impact of deep water diving
Primary Outcome Measures
NameTimeMethod
Variation in Vital Capacity Measurement before and after divingDay +1

Vital capacity measurement will be performed by plethysmography and spirometry (Measurement of mobilizable and non-mobilizable lung volumes (mL))

Secondary Outcome Measures
NameTimeMethod
Variations in lung ultrasound (B lines) before and after divingDay +1

A B-line count should be performed, which is defined as vertical artefacts, mobile with breathing, continuous, originating from the pleural line and erasing the other artefacts. These artefacts indicate interstitial damage, the importance of which correlates with their number and a very good correlation with the quantity of extrapulmonary water.

Variations in lung ultrasound (condensations) data before and after divingDay +1

Ultrasound signs of condensation or pleural effusions should be observed before and after diving.

Variations in right ventricle function data before and after divingDay +1

Right ventricular systolic function is assessed by measuring the tricuspid annulus plane systolic excursion (TAPSE) in TM mode and calculating the LV shortening fraction.

Variations in biological markers of coagulation activation before and after divingDay +1

Measurement from the serum library (venous blood samples) of coagulation factors (TFPI, procoagulant microparticles, Fibrin monomer, PF4, C3a, C5a and platelet count) before and after diving. The analyses remain to be specified according to the results of other ongoing investigations

Variations in plethysmography data before and after divingDay +1

Measurement of DEP (L.S), DEM 75 (L/S), DEM 50 (L/s), DEM 25 (L/S) before and after diving by plethysmography

Variations in DLCO before and after divingDay +1

Measurement DLCO (mmol/(min\*kPa) before and after diving

Variations in decompression (circulating bubbles) data before and after divingDay 0 (after diving)

Detection of circulating bubbles by trans-thoracic ultrasound

Variations in lung ultrasound (condensations) before and after divingDay 0 (after diving)

Ultrasound signs of condensation or pleural effusions should be observed before and after diving.

Variations in biological markers of inflammation before and after divingDay +1

Measurement of inflammation factors (CRP and IL1-β) from the serum library (venous blood samples) before and after the dive. The analyses remain to be specified according to the results of other ongoing investigations.

Variations in water balance before and after divingDay +1

Pre- and post-dive water intakes are quantified but no intake restrictions are requested : Weight measured by electronic scale (in kg)

Variations in Spirometry data before and after divingDay +1

Measurement of SPO2 (%), CVF (L), VEMS (L), VEMS/CVF (%), DEP (L/S) and DEMM (L/S) before and after diving by spirometry

Variations in cardiac ultrasound pulmonary pressure (PAPs) before and after divingDay +1

Pulmonary arterial pressures are assessed by studying pulmonary artery Doppler flow (Acceleration Time) and right ventricular ejection time (RVET) and calculating the Acceleration/RVET ratio.

Variations in biomarkers of lipid peroxidation before and after divingDay +1

Measurement from the serum library (venous blood samples) lipoperoxidation (F2-Isoprostane) before and after the dive. The analyses remain to be specified according to the results of other ongoing investigations.

Variations in biomarkers of oxidative stress before and after divingDay +1

Measurement from the serum library (venous blood samples) of oxidative stress factors (as F2-Isoprostane, 8-isoprostane) before and after the dive. The analyses remain to be specified according to the results of other ongoing investigations.

Trial Locations

Locations (1)

CHU de BREST

🇫🇷

Brest, France

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