# Chest Pain and Oxygen



## Street Doc (Apr 13, 2009)

Pt with legitimate Chest Pain, stable vitals, SPO2 99%, and little or no EKG ectopy.  Now, do they get a nonrebreather or nasal cannula?  I always use a NRB but lately I have been getting questioned by some RN's.  
My reason is this...  When someone is having a possible CVA they get a NRB even with a good SPO2 in an attempt to get the most possible O2 past the blockage or bleed.  Can someone tell me what the difference in treatment is between a CVA and a MI in respect to oxygen getting through to damaged tissue.


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## daedalus (Apr 13, 2009)

Actually, according to the Mosby Paramedic text, a stable CP patient, and a non-hypoxic CVA patient both receive nasal cannula.


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## MSDeltaFlt (Apr 13, 2009)

http://www.rsm.ac.uk/media/downloads/j07-03oxygentherapy.pdf

http://jrsm.rsmjournals.com/cgi/content/citation/100/3/130

Here are some articles and there are others.  What these articles and others like them are saying is that the old mentality of "if some is good, then more is better" is not always the case.

Not every CP requires a NRM.  Treat your pt, not tradition.


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## maxwell (Apr 13, 2009)

By the book, everybody getes 100% O2 by NRB.  If anybody has an SaO2 of 99%, chillin' on room air, I give them an NC just to look cool.  The NRB is sometimes a little dramatic and can make the patient uncomfortable (I mean...not that prongs up their nose doesn't).  The moment their sats go below 95% (of course, with a good waveform), they get 15L so I can stop worrying about it.

The amount of oxygen you're giving them has nothing to do with how much the tissue is getting, assuming their sats are good (>95%).  If there's a blockage, heck, you could give IV oxygen (please don't try this, it's called an embolism, and it doesn't end well) and it wouldn't get to the tissue that needs it.


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## Onceamedic (Apr 13, 2009)

I have a rule of thumb - if they are satting above 90, the get the NC - below that - NRB.....


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## MSDeltaFlt (Apr 13, 2009)

Street Doc said:


> Pt with legitimate Chest Pain, stable vitals, SPO2 99%, and little or no EKG ectopy. Now, do they get a nonrebreather or nasal cannula? I always use a NRB but lately I have been getting questioned by some RN's.
> My reason is this... When someone is having a possible CVA they get a NRB even with a good SPO2 in an attempt to get the most possible O2 past the blockage or bleed. *Can someone tell me what the difference in treatment is between a CVA and a MI in respect to oxygen getting through to damaged tissue*.


 
Also, you're not going to get O2 past the blockage to damaged tissue.  Only those MD's or DO's who are trained in the intervention of these processes can do that.

What we are to do as prehospital emergency care providers is to maintain adquate oxygenation (SpO2 = 95-99%) and adequate ventilation (PaCO2 = 35-45 torr).  Sometimes that is easier said than done.  Which is where knowledge, training, and skill as a patient advocate comes into play.


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## VentMedic (Apr 13, 2009)

daedalus said:


> Actually, according to the Mosby Paramedic text, a *stable CP patient*, and a *non-hypoxic CVA* patient both receive nasal cannula.


 
Key words in bold. 



Street Doc said:


> Pt with legitimate Chest Pain, stable vitals, SPO2 99%, and little or no EKG ectopy. Now, do they get a nonrebreather or nasal cannula? I *always use a NRB *but lately I have been getting questioned by some RN's.
> My reason is this... When someone is having a possible CVA they get a NRB even with a good SPO2 in an attempt to get the most *possible O2 past the blockage or bleed.* Can someone tell me what the difference in treatment is between a CVA and a MI in respect to oxygen getting through to damaged tissue.


 
Key words in bold.

Were you just looking for ectopy? What about ischemia on a 12-lead? Structural problems associated with the thoracic region? 

What are the underlying problems? What are the associated problems? Length of time for more definitive treatment? 

What are the oxygen demands of the patient? Would the demand be met better if cardiac output and perfusing pressures are appropriately managed? 

While the SpO2 "number" is okay for some assessments, it tells nothing of tissue oxygenation or O2 delivery. However, other parts of the assessment will provide you with clues to that. Increased MV can compensate, at least for a short while, for some issues concerning the energy cycle. 

The idea is to identify, correct and wean the O2 quickly with recommendations of 2 to 6 hours of initiation. All factors must be considered as well as your ability as a Paramedic to manage symptoms and maintain an SpO2 greater than 90% by maintaining cardic output and mean arterial pressures or perfusing pressures. Applying O2 is just one part of the equation. If the patient is very symptomatic with an SpO2 of 95%, that number may be skewed by other issues and clinical judgement will have to overrule recipes. 


http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=15765131



> Conclusions
> Oxygen, beyond its indispensable role in cardiac energy metabolism, plays a central role in other biological processes that can be determinants of cardiac function, including the generation of ROS and the determination of cardiac gene expression patterns. Although their role in the pathogenesis of clinical heart failure remains unclear, ROS have been implicated in most processes thought to have a significant effect on cardiac function, including hypertrophy, ion flux and calcium handling, EC coupling, extracellular matrix configuration, vasomotor function, metabolism, gene expression, and downstream signaling of several growth factors and cytokines. Clinical trials based on antioxidant therapies have been, however, generally disappointing. Whether this is a function of the particular antioxidants used is unclear, and planned trials with XO inhibitors and other alternative agents should help answer this question. The role of hypoxia-induced alterations in gene expression in the genesis of heart failure also remains unclear, although experimental data suggest that these changes in gene expression can be either adaptive or maladaptive, depending on context. Given the central role of oxygen in cardiovascular biology, further investigational focus on oxygen-related processes in the genesis of heart failure is warranted.


 
Several studies later throughout the past 100 years have still reached no definitive conclusion. Thus, we still abide by getting a patient off the oxygen clock or reducing O2 therapy when conditions allow.


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## MSDeltaFlt (Apr 13, 2009)

Yeah, her references are better than mine.


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## marineman (Apr 13, 2009)

Per protocol below 95% gets NC, below 90% gets NRM. Per common sense look at patient and provide O2 that keeps them close to pink and away from blue.


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## rhan101277 (Apr 13, 2009)

Yeah 95% means you are getting 95% to the finger.  Other tissues/organs could be getting less perfusion for whatever reason, CVA, blood clot etc.


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## Street Doc (Apr 13, 2009)

Thanks, I trust you guys and gals.  I just always remembered back in basic class that all CPs and CVAs get NRB's and figured why should that change just because im a paramedic now.  Also thought the RN's didnt like the NRB's because I work in the getto and some health care _professionals_ do as little as possible for some of there patients :sad: (not everyone but even one of em is too many, and its not only hospital staff).


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## JPINFV (Apr 13, 2009)

rhan101277 said:


> Yeah 95% means you are getting 95% to the finger.  Other tissues/organs could be getting less perfusion for whatever reason, CVA, blood clot etc.



95% is 95%. The problem with blocked perfusion is that while 95% of the RBCs passing the blockage is oxygenated, you're looking at a lot less RBCs passing the blockage. The difference between dissolved O2 between room air and a non-rebreather is the difference between extremely little and very little.


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## VentMedic (Apr 13, 2009)

Street Doc said:


> Thanks, I trust you guys and gals. I just always remembered back in basic class that all CPs and CVAs get NRB's and figured why should that change just because im a paramedic now. Also thought the RN's didnt like the NRB's because I work in the getto and some health care _professionals_ do as little as possible for some of there patients :sad: (not everyone but even one of em is too many, and its not only hospital staff).


 
It shouldn't matter where you work. Those that stereotype themselves by location do not do any of the medical professions a favor. We'll ask EMT(P)s why a NRBM was used when they bring a patient to our ED in case there were more symptoms that you saw initially that warranted it. If the only answer one can come up with is "its in the protocols", then oh well... We figure you just followed the recipe or your medical director doesn't trust you to think for yourself. If someone has kept up with their education or at least read a few journals lately, they can come back with an intelligent answer to even pursue a conversation, time permitting, about different theories of various therapies. 

Right now there are not many right or wrong answers to most O2 therapy used emergently provided you know why you are doing it and for the amount you have chosen. There are few absolutes for O2 or no O2 initially and those can be debated depending on the protocol they are associated with and the guide may not always be SpO2. However, long term use of O2 at high concentrations is fairly well documented for its effects on the body but that may not be an issue for most EMS situations. 

One must also recognize the limitations of the field and sometimes hospital staff forget you do not have immediate access to a lab analyzer for an A-a gradient, lactate level or SvO2. ED staff and the ICU staff may also have differing opinions as will the Cardiologist and the Pulmonologist or Critical Care physicians.


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## ea632 (Apr 22, 2009)

N/c..........


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## VentMedic (Apr 22, 2009)

ea632 said:


> N/c..........


 
Is this a way of saying "no comment"?


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## Sasha (Apr 22, 2009)

VentMedic said:


> Is this a way of saying "no comment"?



Maybe he means nasal cannula? Either way the response was kind of odd.


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## medic417 (Apr 22, 2009)

Sasha said:


> Maybe he means nasal cannula? Either way the response was kind of odd.



Maybe telling us he is from North Carolina?:wacko:

Vent thanks for some good responses and reference material.


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## DV_EMT (Apr 22, 2009)

what about blow by O2 via NRB... helps deliver that extra 1%, pumps out more O2 in LPM, and probably is more effective in reducing pain or n/v that the pt may be experiencing?


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## LAS46 (Apr 22, 2009)

According to the book I have each patient no matter what gets NRB 15lpm.

Dustin
MFR, NREMT-B Student


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## JPINFV (Apr 22, 2009)

Ahh, one of the many divergences from cook book and reality.


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## Mountain Res-Q (Apr 22, 2009)

LAS46 said:


> According to the book I have each patient no matter what gets NRB 15lpm.
> 
> Dustin
> MFR, NREMT-B Student



American EMS, teaching First Rescpnder not to think and apply medical knowlesge in pateint care since 1970.

FR #1:  "Hey chief, this guys turning blue, what should I do?"
FR #2:  "I dunno.  What does the course book from your 50 hour class that you carry around with you telll you to do?"
FR #1:  Wait, hold on.  Let me see...  Oh, give him oxygen and/or breath for him..."
Paramedic (who just showed up):  "Well thank god you just got your First Responder, this man could have died!"


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## reaper (Apr 22, 2009)

LAS46 said:


> According to the book I have each patient no matter what gets NRB 15lpm.
> 
> Dustin
> MFR, NREMT-B Student



Here's some new advice. Take that book and burn it. Now go back to school and further the education of medicine( not EMT-B).


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