# o2 Bottle Question



## mreid99

I am looking over various sources of material while studing for the NREMT and I found this question. 

You should use a new oxygen cylinder when the old one reaches _______ psi.  
 200 
 500 
 50 
 350 
 I found this question on the princeton hall site ( http://wps.prenhall.com/chet_limmer_emergencycare_10/0,9043,1281755-,00.html )

my book AAOS 9th ed states most EMS services consider a tank less than 500 to 1000 psi too low. So I answered 500. I got it wrong according to  Princton Hall, without getting into the real world answer which is the correct answer for the test.

I look forward to your assistance and opinions.

Mark


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## akflightmedic

ARe you sure the study guide is right and did not misprint??

Real world answer, I have worked for several different services and we always changed at 500 Psi.That was the rule and standard for many years.


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## mreid99

Not clear on the misprint, but the princeton hall says the answer to their question is on page 157 , if anyone has their book.

The only time 200 pis came up was when the tank needed air in it to prevent rusting, I'll check with my P1 instructor on wednesday.


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## monkeyfeet

since i have the book and it's sitting next to my computer, page 157 says the answer is 200.


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## mreid99

I figured that book would say so, thanks I'll evist that chapter and see if 200 pops up in there.

Thanks again


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## KEVD18

i have two different personal standards, depending on the circumstances:

prior to the start of a call, if i find my tank to be less than 500psi, i will swap my primary for my spare

during a call, i will closely monitor the tank, but wont swap it until its fairly well empty.

the book answer, no clue...


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## yowzer

I change the main tank at half, but that's on a critical care unit that does a lot of ventilated high-flow O2 patients. It's common to kill 1 or 2 small bottles (D?) just getting to and from hospital bed and ambulance.

They get changed at 500 or so for BLS units.


Why in the world is this type of question even on the NR test? It's a company/department policy issue, really, not anything to do with patient care as long as you don't run out of ohs when you need it.


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## DT4EMS

When I worked in FL and here in MO is has always been a standard to change at 500. Murphy's law says if you wait until 200, you will run back to back calls and run out of O2.

Do that......... and your career is done.


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## KEVD18

i was refering to my portable, not the main. policy says the main gets changed at 500, and we use a cascacde for the portables so they get filled every day("filled" used loosely. anybody with cascade experience know what i mean"

as far as back to back calls, i dont put my unit back in service till its good to go. if the portable is above 500 its stays. below, its changed. while in the truck theyre on the main and if the protable was depleted from pt contact to the truck, i'll swap them during t/p


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## MMiz

We changed at under 500, but the number 200 was my first thought when I read the question.


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## Tincanfireman

MMiz said:


> We changed at under 500, but the number 200 was my first thought when I read the question.


 
I agree; 500 PSI seems to be the common street answer, but you have to go by the book on those tests  . FWIW, we have one person who changes them out at a thousand, "because you never know what will happen next" (this is with 2x spares on the unit, btw ). Some people's kids...


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## Alexakat

I've always been taught (for written test purposes, in class) "200 psi is considered empty", however, in real life, I'll swap out portable bottles that are 500 or less.  I don't like taking any chances with this type of thing.


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## Airwaygoddess

MMiz said:


> We changed at under 500, but the number 200 was my first thought when I read the question.



Ditto! Almost every textbook states 200psi.  In the working world of EMS the tanks are changed out at 500psi.


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## mreid99

Thanks for the answers, I've only found one place where AAOS mentions 200, and that was in a formula.


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## FF/EMT Sam

We change the "on board" (big) tanks at 500 and the little (jump bag sized) ones at 200ish.


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## Guardian

I always just make sure the needle is in the green or close to it or at least not on red, most of the time that is.


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## mreid99

Well I ws going thru a test prep for the AAOS and found this TQ:

46:  An EMT-B must switch oxygen cylinders before the pressure gauge reads ______ psi. 
 A: 200
B: 400
C: 600
D: 800

Reason: If the psi reads 200, the oxygen cylinder must be changed so that adequate oxygen is available for the next patient who may need it 

The only palce I did ever see that number in the 9th ed was in a formula.

Thanks for everyones assistance, I take the National in 9 hours...


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## Airwaygoddess

Good luck my friend!  May the O2 be with you, remember to BREATH!!!!!


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## mreid99

Well the breathing is over, now it's time to hurry up and wait. Some of the quesitons were easy, others I had to really think about it. 

So here to waiting two more days....


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## mreid99

Whew, NREMT passd. It's done for another 10 months before the next major exam....

I had been so stressed out I only had 70 something questions on my test.


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## FF/EMT Sam

mreid99 said:


> Whew, NREMT passd. It's done for another 10 months before the next major exam....
> 
> I had been so stressed out I only had 70 something questions on my test.





Congrats!!!!!!!!!  :beerchug:


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## MMiz

mreid99 said:


> Whew, NREMT passd. It's done for another 10 months before the next major exam....
> 
> I had been so stressed out I only had 70 something questions on my test.


Congrats!

Would you mind starting a new thread with some basic information about your computer-based testing experience?  I know a lot of our visitors would appreciate the information.

Again, congrats!


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## mfrjason

your oxygen tank should be changed when it reaches 50 psi,cuz you never know what you are going to run into or how long you are gonna be on a scene and dont want to run out of oxygen when you are treating someone.


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## Ridryder911

mfrjason said:


> your oxygen tank should be changed when it reaches *50 psi*,cuz you never know what you are going to run into or how long you are gonna be on a scene and dont want to run out of oxygen when you are treating someone.



50 psi ? Wow, that will give you maybe a minute or so... Did you mean 500 psi, which is considered red line. Most states describe either 250 or 500 psi. 

R/r 911


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