SPS211/FSRUiTM

Hyperbaric Conditions

Exercising Underwater

SPS211/FSRUiTM

Water Immersion & Gas Pressure

• Submersion in water exposes the human body to a hyperbaric condition – external pressure is greater than sea level

• Because volume decreases as pressure increases, air that is in the body before it goes underwater is compressed when the body is submerged

• Conversely, air taken in depth expands during ascent

SPS211/FSRUiTM

CV Response to Water Immersion

• Water reduces the stress on CV• When body submerged:

– Plasma volume increased– RHR drops– Effect is enhance by cold water

• Hyperventilation is often practiced before breath-hold diving to increase underwater stay – can lead to lose consciousness

• During breath hold diving, the gases in the body can become pressurized (even 1 or 2 meter deep)

SPS211/FSRUiTM

Health Risk of Hyperbaric Conditions

• Oxygen Poisoning– Less O2 & CO2 remove from the

hemoglobin– Decrease blood flow to the brain

• Decompression Sickness (the bends)– Ascending too rapidly– The N+ dissolved in the body cannot be

removed by the lungs quickly enough, so it form bubbles

– The bubbles can form emboli – R.I.P

SPS211/FSRUiTM

Health Risk of Hyperbaric Conditions

• Nitrogen Narcosis– Narcotic effects of nitrogen when is partial

pressure is high (depth diving)– Symptom – similar to alcohol intoxication

(impaired judgment – fatal mistakes)

• Spontaneous Pneumothorax– Ruptured eardrum– Cause by changing pressures