I was on a call the other day, 50s male with chest pain, cardiac history, pain 8/10, etc. Pulse about 80. NYS BLS protocol states that high flow oxygen should be given via non-rebreather mask. This has been the protocol for the past 20 years at least, and is also considered routine medical care for all levels in our area.

ALS arrives on scene while I prepare the NRB. The ALS tech says "No, put him on 4 lpm with a cannula." I considered that a moment, then said "Nope, I'm giving him 15 per protocol."

Two or three minutes later, the patient reported vast relief from pain with the NRB. Having transferred care over to another crew, I watched as the ALS tech removed the NRB so as to get a room air sat level.

Apparently, there is some belief that indicates that too much oxygen can constrict the cardiac vessels and complicate the situation. However, a "belief" is overruled by protocol, in my book.

Any thoughts or data on this?

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There is some good evidence that providing the patient with a little temporary comfort may be harmful to their overall outcome, as in this historic study http://www.rsm.ac.uk/media/downloads/j07-03oxygentherapy.pdf

There is evidence going back as far as 1965 that high oxygen concentrations can be substantially harmful. The study I linked shows comparative angiograms where high-flow oxygen actually caused coronary artery vasoconstriction and reduced the coronary blood flow.

There's increasing evidence that - no matter what we have been taught - that high-flow oxygen sometimes causes more harm than good. The first rule of medicine is Primum Non Nocere - First, Do Ho Harm.

A lot of what we do in EMS isn't scientific - it's 30 or 40 years of urban legends.

An example - show me a single study that proves that using a KED or other short spine immobilization device is of any medical value. You can't, because no such study exists. However, studies showing that high-flow oxygen can be harmful to patients with high oxygen saturations does exist, and we need to start paying attnetion to it.
You have a very good and valid point. This is why a lot of places have gone from requiring 15Lpm to 10Lpm via NRB if suspected MI. If a patient is having an active MI, you should never withhold O2, it's kinda what they need at that point. I do know that hyperoxygenating patients with head injuries has shown to be harmful, it can increase ICP, but again that is why they say to ventilate the patient whenever you take a breath. As far as coronary vasoconstriction through O2 administration, that is usually relieved with nitro and morphine, both of which are fantastic at coronary dilatation. We have to look at the whole picture when treating patients with grave injuries and illnesses. I know where I live, we usually have transports that are no more than 10 to 15 minutes. How long are you guys transporting? That could very well make a huge difference in treatments.
Maybe that medic was exactly following his protocols. There are many services - including mine - that have ALS protocols that give oxygen based on oxygen saturation, patient tolerance, and patient complaint/mechanism of injury.

If the medic in question wasn't following his/her protocols, that's a different story, but expecting someone who doesn't work for your system to follow your protocols isn't realistic.

4 lpm via a nasal cannula isn't "witholding" oxygen, either.
I must disagree. Not every "medic" knows what they are talking about. Simply possessing a certificate showing you passed a class doesn't make you a seasoned provider.

Granted the responsiblity lies on the senior "credentialed" provider on scene, in this case the ALS tech. But that doesn't mean he is always going to be right.

More often than not, we are going to 10-12 LPM by NRB, 4LPM by NC, and only using 15 LMP for BVM where 100% is required.
Here in the UK, the discussion between using and not using (or reducing) O2 with COPD/COAD patients has been raging for a while, but ultimately we're here to treat the symptoms of the initial complaint. In the case first talked about on here (many pages ago), we'd be treating for cardiac related problems, in particular, Q-MI. We're not treating for COPD/COAD. In most cases, the hypoxic drive issue won't be a problem, and even if it was to be a problem, it's something that would usually come on after hours of high flow O2, and not within the short time space we're usually with the patient.

For us here in the UK, if the 12 lead is showing a confirmed MI (ST elevation of 2 small squares or more in three or more leads as a rule), then O2 is given at full flow 100% NRB. Besides, high doses of O2 can actually have a thinning effect on the blood, hence why we don't give O2 to CVA patients with sats of 95% or more otherwise it can can increase the bleed rate (assuming it's a bleed thats causing it). Not sure if you guys do the same in the US mind?
CYA Lesson 1: Document Document Document!!! If you put the PT on 15 lpm NRB per protocol document it, document that the medic wanted to put the PT on 4 lpm NC against protocol, contact your medical director/EMS supervisor/other person in your change of command if you feel it necessary to correct the medic. our rule in MD, and my rule is that if you have a PT with chest pain or trouble breathing they are getting 15 lpm NRB. All critical PTs get 15 lpm NRB except stroke/CVA PTs who are contraindicated for high-flow O2. If I am rifing 3rd on the medic unit and the EMT-P says to put the PT on NC, then I do it, as he is my superior and I am under his supervision and he is ultimately responsible for the PT, not me.. But my PTs get high-flow. For my British compadre above, we give 4 lpm NC to CVA PTs as it won't increase the rate of blood loss.
ALS person was wrong? I've never met a field provider that withholds O2 to get a room air sat. We all know that number is useless.
As far as the NRB/NC debate, was there a full medical history exam? Ever tried to talk to someone through a NRB?
As a Paramedic, I often have to remove the 15 lpm hissing mask in order to establish the patient's condition, then replace it, then remove it etc etc.
A cannula at 4-6 lpm can provide good O2 (not great) while we establish our plan.
When we no longer need to get constant information from the patient we can go NRB if conditions allow.

And telling the ALS provier "nope", just asking for trouble in my mind.
Great topic Joe, thanks for sharing!

Happy Medic
I do have to agree with you here. There is a serious disconnect between book smart and field smart these days. I was an EMT for 10 years before I became a Paramedic. When I first got into this business, you had to prove to your preceptors that you could handle anything and with clinical reasoning. Today, I feel bad for some of the patients that I have to leave with the transporting Paramedic. They are extremely book smart and can pull a ton of useless info out, but as far as taking care of someone....it's pretty pathetic. Great point!
I'm still waiting to see the patient with the O2 saturation of 105%.
If they're 100% saturated on 4 lpm, then peeling their eyelids out of their head with a high-flow non-rebreather mask won't increase the O2 saturation at all.
Joe , I am glad to read your posting ,you did the right thing ! Stick to the protocols , another shining example of an EMT saving a medics Butt ! :)
In the past,I too have been saved by my EMT partner- when I might be tired and willing to "cut corners", he gives me a needed reality check :)
The data I've seen shows what you saw- vast reduction in chest pain with high flow oxygen quickly, its only after a long period of high flow o2 that vessel constricure can occur , and the patient NEEDS the oxygen right
then !
keep the faith,stay safe ,
Al Westbrook Tn-EMTP/ FF II
I have read the replies to your discussion. Not all so perhaps it has been mentioned already. AHA guidleines now recommend 4 lpm NC on cardiac issues. Of course you will need to titrate to signs and symptoms. I can understand how this seems contrary to what you have been taught and done for the last few years. When I was an EMT it was hammered into us to always use a nonreabreather high flow O2. But with more studies, more data and research we are continually updating and modifying treatments and protocols. It is possible to hyperoxygenate a patient. More O2 is not always the right answer. Referencing the mentioned belief of too much O2 constricts cardiac vessesls, there was a study which was published in the Journal of the Royal Society of Medicine that you can read. "The limited evidence that does exist suggests that the routine use of high-flow oxygen in uncomplicated MI may result in a greater infarct size and possibly increase the risk of mortality. " Remember that oxygen is a drug and a higher adminstration of a drug is not always the best answer.
As for the conflict on scene, my recommendation to you would be to have gone ahead and adminsitered the O2 via nasal canula and discussed with the paramedic after the call what his/her reasonings for doing so were. I know that in our EMS system EMT protocols differ slightly from Paramedic protocols. Please have faith in the paramedic that they are looking out for the patient's best interest. I know that I am always open to learning/teaching after a call. I don't believe the most teachable moment is necessarily in the middle of a call. There is a lot of stress and activity in critical calls. Thanks for the great topic.
I know I'm still new, but I know enough that unless you are on the call and know everything excalty how it happened then u dont know excatly how it happened. There are so many other things on a call that may have played a part in what the medics were doing. once als is there, its their patient, not yours. transfer of care

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