Oxygen supply Hyperbaric medicine

a recompression chamber single diving casualty

in larger multiplace chambers, patients inside chamber breathe either oxygen hoods – flexible, transparent soft plastic hoods seal around neck similar space suit helmet – or tightly fitting oxygen masks, supply pure oxygen , may designed directly exhaust exhaled gas chamber. during treatment patients breathe 100% oxygen of time maximise effectiveness of treatment, have periodic air breaks during breathe chamber air (21% oxygen) reduce risk of oxygen toxicity. exhaled treatment gas must removed chamber prevent buildup of oxygen, present fire risk. attendants may breathe oxygen of time reduce risk of decompression sickness when leave chamber. pressure inside chamber increased opening valves allowing high-pressure air enter storage cylinders, filled air compressor. chamber air oxygen content kept between 19% , 23% control fire risk (us navy maximum 25%). if chamber not have scrubber system remove carbon dioxide chamber gas, chamber must isobarically ventilated keep co2 within acceptable limits.

a soft chamber may pressurised directly compressor. or storage cylinders.

smaller monoplace chambers can accommodate patient, , no medical staff can enter. chamber may pressurised pure oxygen or compressed air. if pure oxygen used, no oxygen breathing mask or helmet needed, cost of using pure oxygen higher of using compressed air. if compressed air used, oxygen mask or hood needed in multiplace chamber. monoplace chambers can fitted demand breathing system air breaks. in low pressure soft chambers, treatment schedules may not require air breaks, because risk of oxygen toxicity low due lower oxygen partial pressures used (usually 1.3 ata), , short duration of treatment.

for alert, cooperative patients, air breaks provided mask more effective changing chamber gas because provide quicker gas change , more reliable gas composition both during break , treatment periods.