Emergency oxygen delivery systems

Question 1

Which primary categories does emergency oxygen equipment fall into?

Answer 1

non-resuscitator demand valve units (NRDVU)
continuous flow units (CFU)
positive pressure resuscitator units (PPRU)

Question 2

What’s one of the most important first aid steps for a diver suspected of having decompression sickness, lung over-expansion or drowning?

Answer 2

supplying emergency oxygen
-> improves immediate condition and effectiveness of subsequent treatment

Question 3

Which types of emergency oxygen equipment do rescue divers use?

Answer 3

non-resuscitator demand valve units
continuous flow units
-> positive pressure resuscitator units require special training

Question 4

How do non-resuscitator demand valve units work?

Answer 4

like scuba regulator
-> oxygen only flows while diver inhales
-> support mouth to mouth ventilation (lungs only use fraction of the oxygen -> rescuers can use emergency oxygen as source)

Question 5

Why are non-resuscitator demand valve units the best choice for rescue divers?

Answer 5

dive accident first aid: deliver highest oxygen concentration possible for as long as possible

Question 6

How do continuous flow units work?

Answer 6

release oxygen continuously
6-10 l/min (25l with adjustable ones)
oxygen flow normally 90%, with improper use may drop below 60%
-> best use for divers with no breathing

Question 7

Can NRDVU’s be used for continuous flow supply?

Answer 7

yes, most have a system to provide continuous flow

Question 8

What’s the recommended flow amount for continuous flow units?

Answer 8

15l/min

Question 9

Why do you need special training to use positive pressure resuscitation oxygen systems?

Answer 9

they produce pressure
-> with improper use: may lead to over-pressurisation of lungs

Question 10

is there a way you can use PPROS?

Answer 10

you can use manually triggered resuscitator valves
-> still need some training, but relatively safer

Question 11

How long do 637l oxygen last?

Answer 11

40-50 mins, depending on continuous flow or NRDVU

Question 12

Are you allowed to provide oxygen to an unconscious diver?

Answer 12

yes, consent is implied

Question 13

Why is applying oxygen not harmful in most cases?

Answer 13

you would have to inhale highly concentrated oxygen for hours before it causes lung irritation

Question 14

If you have no emergency oxygen, how can you still provide extra oxygen?

Answer 14

give enriched air (EANx)
-> works as substitute