Oxygen rate for Chest Pain?

[AnthonyM83]

I know we've discussed O2 rates variosu times, but I couldn't find any that relate to chest pain.

For CP, which you believe to be cardiac in nature, what flow rate do you use? I have always been taught high-flow with NRB both in EMT class and that's what medics tell us to do on-scene, with the concern the if heart is ischemic you want to give it more O2 to compensate.

I was recently told that other areas of the country give NC only and one of the benefits would be keeping the patient calm, thus reducing HR and workload of heart. Is that what you guys are doing out there? Also, is 4-6lpm NC really enough if there's cardiac ischemia happening?

[katbemeEMT-B]

I think this would be a case by case answer. It would be dependent upon the patient hx and the history of the current episode. Again, you can't apply cookbook methods to all patients. This is why patient assessment and critical thinking is so important. I have treated chest pain with both NRB high flow and NC. After assessment of the patient and determining what his/her needs are you make the decision that you feel will best benefit him/her. The other thing to remember is that not all calls for chest pain turn out to be an issue with the heart. I have seen this many times also.

I actually just returned from a call for chest pain. The patient was oxygenating at 97% room air but because he has a heart hx complicated by anxiety the decision was made to apply 12LPM O2 via NRB. His SATS came up to 100% and his anxiety was somewhat decreased. It turns out his pain was actually due to stomach issues, (acid reflux I would assume).

[Chief1C]

enough to keep the bag inflated properly. 10 or 12 should do it.

[ccmedoc]

Yes, case by case is correct. The problem with high Fio2 is that the patient will experience some vasoconstriction eventually with decrease in cardiac output and oxygenation. Depending on the patients respiratory status and sat. It would be wise to use lower Fio2 initially to keep the sats obove 91% min. If there is no associated respiratory distress of decomp, NC is the best choice with the option to progress to higher flow. The last thing to do in the event of possible/probable MI is to compromise CO and oxygenation by a seemingly benign intervention such as oxygen delivery.. Be safe... Very good question with lots of research available on the effects of oxygen admin and intox..

[AnthonyM83]

To those who spoke about case by case basis, so what factors/hx would influence your decision. Remember, this is simply for CP that you BELIEVE to be cardiac in nature (based on hx and case by case). No SOB or signs of resp. distress.

ccmedoc, I appreciate your answer. So, you'd feel comfortable with a low O2 level that is keeping sats at 92%? The reasoning being that heart would get more O2 this way than if there was a higher O2 sat in blood because the high O2 volume would lead to vasoconstriction and decreased cardiac output? Now my next question would be is that decreased cardiac output going to be that bad? Decreased CO be okay (if no other medical hx like CHF)? Wouldn't it decrease workload of the heart even more (and thus decrease tissue damage), provided the patient was calm?

I'm just working things out in my head. Thanks for the comments.

[Richard B the EMT]

Anthony, just mentioning my local (FDNY)and state (New York) protocols, if a patient needs oxygen, they get it at 10-15 liters per minute via a non re-breather mask.

If the patient cannot or will not tolerate an NRB, then go with a cannula @ 6 LPM.

If they cannot or will not tolerate even the cannula, try "blow-by", which is basically stupid sounding but kind of works, that of attaching a paper cup to the end of an oxygen delivery tube via a hole in the bottom of the cup, and holding it a couple of inches from the patient's mouth and nose. Alternate style, just use a big bore type oxygen tubing directly to the same few inches from the patient's mouth and nose.

[ccmedoc]

Well, decreased cardiac output would equal decreased tissue perfusion ie. brain, kidneys, heart, etc. A sat of 92% is not that bad unless there is accompanying respiratory problems, in which case, it possibly may be difficult to acheive this. Another factor is if the pt has a Hx of COPD and is chronically retaining CO2. There are many factors that affect oxygen saturation and oxygen delivery that are beyond the scope of this reply. Generally, classic angina and variant angina respond very well to around 40% FiO2, which would be nasal cannula at around 4lpm. With vasospastic angina, high FiO2 could exacerbate the problem and possibly introduce more problems..It is a long drawn out issue that could be discussed for hours. I believe you will find that most will say that high flow O2 is overkill and possibly harmful..

Peace, Steve

[ccmedoc]

I see that there are both BLS and ALS (presumably) protocols present. As a Basic, I would say to never with-hold oxygen, but as a Medic you should have the freedom to decide whether your patient is in need of the high flow or not. To say that any person with a sat below 95% or so gets high flow oxygen is ludicrous and these decisions should be evaluated. The seemingly harmless overzealous administration of oxygen could be devestating in the wrong patient..be careful and be safe..

-steve

[katbemeEMT-B]

I still say it depends on the patient and situation. How is the patient presenting? What are his SATS, BP, pulse, resp? What is the quality of the pain, severity, does it radiate? What was the patient doing prior to the chest pain starting? So on and so on? An assessment is crucial to treatment

Now, if your assessment shows all vitals in normal range and the pain is not radiating I feel a NC would be sufficient. If there is an abnormality in the patients vitals then I would go with an NRB starting at about 10LPM and increasing if need be. Often times along with the chest pain the patient will have shortness of breath whether from anxiety or the crushing feeling. Resp. count is important here. They may deny SOB but you may see otherwise just by observing how they are breathing. Is the rate normal? What is the quality of resp.

This is why it has to be case by case. You can't apply the same treatment to all patients with chest pain as all patients are not the same.

[ccmedoc]

Here is one study that comes to mind---paradigm buster???

this will either clear it up or make more questions---both are great!! luv the learning!!!

[web:8909a01252]http://www.rsm.ac.uk/media/downloads/j07-03oxygentherapy.pdf[/web:8909a01252]

Steve