First of all, a small correction, I would call 4 lpm low flow oxygen, and
over 10 lpm high flow.
A change, recently, in our emergency medical technician oxygen protocols
allows us to administer oxygen to whomever needs it, regardless of medical
history (i.e. chronic obstructive pulmonary diseases). The crux of this
philosophy being that you must maintain a prudent vigilance in case there
are problems with the oxygen administration. (like they quit breathing!)
Most patients who get oxygen around my hometown get it via a non-rebreather
mask at +12 lpm. This means that the patient breathes as close to 100%
oxygen concentrations as is feasible in the field.
Although I'm not familiar with aviation applications of oxygen, I would
assume that the differences in protocol are probably linked to the
following:
A) I suppose a common reason that oxygen is made available to the
passengers of an aircraft is de-pressurization, or potential. This is
important because, for the most part, the passengers are healthy
individuals. Even if the aircraft swiftly depressurizes a small amount of
supplemental oxygen will maintain lucidity and conciousness. Example:
Let's say an aircraft is cruising at about 30,000 feet and rapidly
depressurizes. The air at that altitude has only about 1/3 the amount of
oxygen that is found at sea level (I'm pulling from memory). That drop in
oxygen can lead to unconciousness and death within just minutes. Therefore,
it is important to get supplemental oxygen quickly. Most climbers on Mount
Everest (elev. 29,028 feet) use only about 2 lpm while above 27,600 feet
(from memory), although some have summitted without oxygen. Much of this
has to do with acclimatization factors, also.
B) When unhealthy individuals receive oxygen for medical treatment they are
in medical need and therefore on a different treatment plan than that of a
depressurization. Medical cases either are in desperate need of oxygen
because they are not breathing adequately or they are not circulating
adequately; or, they need to get ahead of the game because their problem may
intensify(sort of like giving them a head start). That's why we give most
people 12-15 lpm of oxygen via a non-rebreather mask. I would guess that
the aviation masks have been engineered to pull in a certain amount of air
from the outside of the mask to mix with the pure oxygen. That would give
the depressurization passenger enough supplemental oxygen to maintain
conciousness and some lucidity and, also, decrease the amount of oxygen (or
equipment) that needed to be carried on board the aircraft.
C) I would also guess that the pilots of airliners have better oxygen
delivery devices than the passengers. This equipment would provide closer
to 100% oxygen to the people in charge of the aircraft. Oxygen will help
maintain rational thought that may be hampered even by 4 lpm flows when
rapid depressurization occurs.
That's kind of what I see the diffference as, maybe an aircraft person can
give a more aviation sided approach....
Randy Okray randyo_at_vcn.com
Campbell County Fire Department
Training Officer
200 Rohan Avenue
Gillette, WY 82716
(307)682-5319
> -----Original Message-----
> From: owner-crm-devel_at_db.erau.edu [mailto:owner-crm-devel_at_db.erau.edu]On
> Behalf Of Joktan Lo
> Sent: Monday, February 01, 1999 11:10 AM
> To: crm-devel_at_db.erau.edu
> Subject: Usage of O2 Bottle!
>
>
>
> Dear All,
>
> I am curious why when oxygen is administered for passengers
> during flight, high
> flow outlet (4 liters per min) will be used except in the cases
> of emphysema.
>
> One of my friend working as an ambulance first aider told me that
> they usually
> will apply low flow outlet to all kinds of casualty.
>
> Why there is a difference between the method for the cabin crew
> to apply oxygen
> to pax during flight and that for ground first aider to apply
> oxygen to ground
> people? Is that because the pressure in the aircraft is different
> from that on
> ground?
>
> Joktan LO
>
>
>
>
>