Related Experiment Video
Updated: Jun 27, 2026
08:10
Fizzy Extraction of Volatile Organic Compounds Combined with Atmospheric Pressure Chemical Ionization Quadrupole Mass Spectrometry
Published on: July 14, 2017
Predive sauna and venous gas bubbles upon decompression from 400 kPa
Jean-Eric Blatteau1, Emmanuel Gempp, Costantino Balestra
1Hyperbaric Department, Sainte-Anne Military Hospital, 544 Avenue Ernest Roller, Toulon 83200, France. je.blatteau@infonie.fr
Aviation, Space, and Environmental Medicine
|December 17, 2008
Summary
A predive sauna session significantly reduced circulating bubbles after a simulated dive, potentially lowering decompression sickness risk. This effect may involve sweat dehydration and heat shock proteins (HSP).
Area of Science:
- Hyperbaric Medicine
- Physiology
- Environmental Medicine
Background:
- Investigating the impact of far infrared-ray dry sauna heat exposure before simulated dives.
- Examining effects on bubble formation and hemodynamic parameters.
Purpose of the Study:
- To determine if a predive sauna session influences bubble formation post-dive.
- To assess changes in hemodynamic parameters following sauna exposure.
Main Methods:
- 16 divers underwent simulated dives (400 kPa for 25 min) with and without a predive sauna session (30 min at 65°C, 1 hour prior).
- Venous bubbles detected via precordial Doppler; brachial artery flow-mediated dilation (FMD), blood pressure, bodyweight, plasma volume (PV), and HSP70 measured.
Main Results:
- Sauna significantly reduced bubble formation (27.2% to 35.4%).
- Sauna induced extracellular dehydration (-2.7% PV, -0.6% bodyweight loss).
- Increased FMD, reduced systolic blood pressure and pulse pressure observed; plasma HSP70 increased.
Conclusions:
- A single predive sauna session effectively decreases circulating bubbles after chamber dives.
- This may offer a protective effect against decompression sickness.
- Potential mechanisms include sweat dehydration, HSP, and the nitric oxide (NO) pathway.
Related Concept Videos
01:13Excess Pressure Inside a Drop and a Bubble
The shape of a small drop of liquid can be considered spherical, neglecting the effect of gravity. This drop can further be considered as two equal hemispherical drops put together due to surface tension. The forces acting on the spherical drop are due to the pressure of the liquid inside the drop, the pressure due to air outside the drop, and the force due to the surface tension acting on the two hemispherical drops.
01:31Gas Solubility
Gas solubility in liquids forms liquid-gas solutions, such as soft drinks, where carbon dioxide is dissolved in water, and the ocean, where the solubility of oxygen and carbon dioxide supports marine life. The ability of oceans to dissolve gases impacts weather conditions in the troposphere.However, gas-liquid interactions vary. For instance, hydrogen chloride gas is highly soluble in water, while oxygen's solubility is much lower. Because these solutions are non-ideal, Raoult’s law, which...
01:28Vapor Pressure of Fluid
The vapor pressure of a fluid is a crucial concept in fluid mechanics, influencing phenomena such as boiling and cavitation. Vapor pressure refers to the pressure exerted by a vapor at a state of thermodynamic equilibrium with its corresponding liquid phase at a specific temperature. It represents the tendency of molecules to escape from the fluid surface into the vapor phase.
When a liquid is placed in a closed container with a small air space, and the space is evacuated, vapor molecules will...
When a liquid is placed in a closed container with a small air space, and the space is evacuated, vapor molecules will...
01:24Pressure Relationships in Thoracic Cavity
Breathing, otherwise known as pulmonary ventilation, is the process of air movement into and out of the lungs. The main mechanisms propelling pulmonary ventilation are atmospheric pressure (Patm), intra-pulmonary (Ppul ) or intra-alveolar pressure (Palv) within the alveoli, and intrapleural pressure (Pip) within the pleural cavity.
Breathing Mechanisms
Both intra-alveolar and intrapleural pressures rely on specific lung properties. The ability to breathe—allowing air to enter the lungs during...
Breathing Mechanisms
Both intra-alveolar and intrapleural pressures rely on specific lung properties. The ability to breathe—allowing air to enter the lungs during...
02:34Vapor Pressure
When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules move randomly about, they will occasionally collide with the surface of the condensed phase, and in some cases, these collisions will result in the molecules re-entering the condensed phase. The change from the gas phase to the liquid is called condensation. When the rate of condensation becomes equal to the rate of vaporization, neither the amount of the liquid nor the amount of the vapor...
03:28Vapor Pressure Lowering
The equilibrium vapor pressure of a liquid is the pressure exerted by its gaseous phase when vaporization and condensation are occurring at equal rates: Dissolving a nonvolatile substance in volatile liquid results in a lowering of the liquid’s vapor pressure. This phenomenon can be explained by considering the effect of added solute molecules on the liquid's vaporization and condensation processes. To vaporize, solvent molecules must be present at the surface of the solution. The presence of...