Bledsoe O2 Article

VentMedic

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Good article but still many general statements that don't always apply for EMS and other studies have evolved where you must weigh the good with the possible side effects.

Besides a good ventilator, there is little way to actually deliver prehospital O2 at 100% and have enough flow to keep from impeding on the work of breathing. If a patient has a high minute ventilation, the best a NRBM mask might do is 60% with serious work of breathing. Once EMS starts to educate as to what the differences between High Flow, Low Flow and high FiO2 devices actually are, there will be a better understanding how to deliver the proper oxygen. As well, once some take real A&P and pathophysiology, the will be an understanding about the O2 delivery and uptakes systems within the body.

We have known Oxygen's vasodilating and constrict properties for different areas of the body which is why it is used or used at even subambient levels in some protocols. We have also debunked the hypoxic drive theory for its relationship to the majority of COPD patients. Research is constantly studying and coming up with new theories.

One MUST also understand their O2 delivery devices, FiO2 and what is actually meant by O2 delivery and O2 consumption within the body before making blanket statements or recipes. The 2 L or 4 L only is crap as the FiO2 with be totally different between two individuals in even the most ideal situation.

While higher FiO2 may not be required for all patients, withholding O2 for an emergency in the field should not be advocated because of free radicals developing in the 15 minutes you are with the patient.

I can see a lot of knee jerk impulses from some who may read this article but have little understanding of the things I have mentioned in the previous paragraphs and other threads.
 

PapaBear434

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In my experience, O2 usually is quite effective at calming people down. I don't know if it's a psychosomatic response or a real physical one, but I DO know that it definitely helps to get them breathing normally and a little more slowly.

Other day we had a patient that stole a car with some of her friends and crashed during the police pursuit. By the time we had her, she was fully immobilized and handcuffed to the backboard. We of course tried to get info from the girl, and she was just freaking out about us cutting her coat, her getting in trouble, us cutting her pants...

She was sating at 100%, but we stuck a nonrebreather at 12 lpm. She starts calming down after about a minute, enough that we can get her name, address, and all the other "SAMPLE" stuff. I don't know if it was the mask that forced her to slow down her breathing, calming her down, or if it was the O2 itself... But I do know it stopped her from thrashing around enough that we could exam her without fear of her hurting herself even more.

I am going to have to read this thing more thoroughly when I get off shift.
 

AJ Hidell

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Once EMS starts to educate as to what the differences between High Flow, Low Flow and high FiO2 devices actually are, there will be a better understanding how to deliver the proper oxygen. As well, once some take real A&P and pathophysiology, the will be an understanding about the O2 delivery and uptakes systems within the body.
Honestly, I don't expect that to ever happen. EMS keeps adding more and more "skills" to the curriculum, yet refuses to add any hours to the course to teach it. Consequently, the core curriculum gets more and more watered down. An increased physiological content is simply not in the cards for EMS education anytime soon. Too few students will choose a school that lasts longer than the minimum.

Even the very little respiratory education that we give our students is only enough to make them dangerous. I have known three different female EMTs over the years who openly bragged to their co-workers how they removed the oxygen from their own babies' faces when the medical staff wasn't looking because they were convinced by their 110 hour EMT course that it would give the kid RLFP. When I have attempted to educate EMS personnel on the science behind oxygen therapy, I have always been met with blank stares and a lot of grumbling about, "is this going to be on the test?"
 

vquintessence

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So the NRB on the pt was just to calm her down? I know it's all situational, but a lot of time the NRB seems to be an additional stressor for situations.

Can't count the number of times a pt has ripped off their NRB/neb mask while we've been preparing the BVM and/or second line meds.

In your case, did the police ride with you or behind you? Reason I ask is because of the hard restraints and perhaps it was their presence (lack of) that calmed her down ultimately?
 

vquintessence

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... When I have attempted to educate EMS personnel on the science behind oxygen therapy, I have always been met with blank stares and a lot of grumbling about, "is this going to be on the test?"

What level do you teach, and what tends to be the age group?
 

AJ Hidell

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What level do you teach, and what tends to be the age group?
I'm not teaching anymore, having been forced into retirement by my last injuries. But I taught everything from first aid, to EMTs, to Paramedics, to military corpsmen, with an age range from 17 to their 50s. I'd guess the average age range to be in the 20s.
 

VentMedic

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In my experience, O2 usually is quite effective at calming people down. I don't know if it's a psychosomatic response or a real physical one, but I DO know that it definitely helps to get them breathing normally and a little more slowly.

So the NRB on the pt was just to calm her down? I know it's all situational, but a lot of time the NRB seems to be an additional stressor for situations.

Can't count the number of times a pt has ripped off their NRB/neb mask while we've been preparing the BVM and/or second line meds.


Some always say people "hyperventilate" during stress or when they appear anxious. These patients many actually "hypoventilate" or breathe inadequately or inefficiently. Thus, when additional flow with some extra O2 is added, the patients do feel better.

If you are preparing your BVM, you may already have the patient in a supine position. That by itself can be a stressor with or without the NRBM.

But again, the NRBM is a "low flow" device in that it may not be able to provide the total inspiratory flow the patient is demanding.
 

VentMedic

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It has been suggested for decades that high flow 02 can be more damaging in MIs.

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

How many EMT(Ps) are with their patients for 24 hours which is the time frame in that study?

It is common knowledge that a patient goes on an O2 clock with an FiO2 greater than 50 - 60%. But, it may take more medical intervention than what most EMT(P)s can do to increase BP and airway MAP to achieve that goal. While many here can say only 2 L NC per minute in an AMI, but on a failing heart some may not realize what must be done to improve cardiac function enough for that 2 L NC to be adequate. One recipe does not fit all.

If you read these articles, you will also see how we have advanced since 1972 in providing cardiac care. That too has made a difference.
 

PapaBear434

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So the NRB on the pt was just to calm her down? I know it's all situational, but a lot of time the NRB seems to be an additional stressor for situations.

Can't count the number of times a pt has ripped off their NRB/neb mask while we've been preparing the BVM and/or second line meds.

In your case, did the police ride with you or behind you? Reason I ask is because of the hard restraints and perhaps it was their presence (lack of) that calmed her down ultimately?

Well, she WAS handcuffed with both hands to the board, so grabbing the mask off wasn't an option. She was forced to breathe the sweet, sweet O2.

The police were riding behind us, I think. It's hard to say, honestly, thanks to the huge cluster**** that happened on scene. Too many chiefs, not enough Indians. EMS chief said he was in charge. Fire chief said he was in charge. Police on scene were the first there, so they said THEY were in charge. There was more than sixteen patients, so we were just waiting to find out where we were suppose to go and who they wanted us to take, but we had three different departments telling us three different places to go.

The EMS side of things did pretty well, honestly. Once they figured out where all of us were suppose to go, we got our patient and got out of there quick. But getting TO the patient was a huge undertaking unto itself thanks to everyone wanting to be in charge of the MCI and no one wanting to just take orders.

We picked up our patient, loaded her up, and by the time we got the stretcher locked in the officer was telling us to move Move MOVE NOW! So, yeah, I THINK someone was following us. I do know that an officer was at the door waiting for us when we got to the hospital, though.

We should have handled THAT better, and insisted that someone rode with us considering the situation. But with everything else going on, we were just content to get out of there.
 
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abckidsmom

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Well, she WAS handcuffed with both hands to the board, so grabbing the mask off wasn't an option. She was forced to breathe the sweet, sweet O2.

The police were riding behind us, I think. It's hard to say, honestly, thanks to the huge cluster**** that happened on scene. Too many chiefs, not enough Indians. EMS chief said he was in charge. Fire chief said he was in charge. Police on scene were the first there, so they said THEY were in charge. There was more than sixteen patients, so we were just waiting to find out where we were suppose to go and who they wanted us to take, but we had three different departments telling us three different places to go.

The EMS side of things did pretty well, honestly. Once they figured out where all of us were suppose to go, we got our patient and got out of there quick. But getting TO the patient was a huge undertaking unto itself thanks to everyone wanting to be in charge of the MCI and no one wanting to just take orders.

We picked up our patient, loaded her up, and by the time we got the stretcher locked in the officer was telling us to move Move MOVE NOW! So, yeah, I THINK someone was following us. I do know that an officer was at the door waiting for us when we got to the hospital, though.

We should have handled THAT better, and insisted that someone rode with us considering the situation. But with everything else going on, we were just content to get out of there.


Yeah, sounds like a ridiculous scene. I'm pretty sure that I would've pointed out to the cops that they had forgotten and left their handcuffs on the patient. Unless the law enforcement officers are physically with me in the ambulance, there aren't going to be handcuffs on my patients.
 

vquintessence

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Some always say people "hyperventilate" during stress or when they appear anxious. These patients many actually "hypoventilate" or breathe inadequately or inefficiently. Thus, when additional flow with some extra O2 is added, the patients do feel better.

If you are preparing your BVM, you may already have the patient in a supine position. That by itself can be a stressor with or without the NRBM.

But again, the NRBM is a "low flow" device in that it may not be able to provide the total inspiratory flow the patient is demanding.

True enough. Hyperventilation clearly doesn't allow adequate ventilation or exchange. I'd be a fool to argue "extra breathing means extra oxygen". Comparable are those among us who are transporting someone on a vent, notice the spO2 falling & pt deteriorating, so they increase the ventilators rate... not having an understanding to the I:E ratio their pt requires.

Also can't argue that the O2 hurts the pt in Papa's situation. I was playing devils advocate questioning how the presence of a low flow mask could be exacerbating the situation, causing the hyperventilating pt to fight more and have her body require more O2 during a situation she is already lacking exchange. From what I understood, you said as much on both hands? :)

Papa, sounds like you had one hell of an incident to deal with.
 

VentMedic

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True enough. Hyperventilation clearly doesn't allow adequate ventilation or exchange. I'd be a fool to argue "extra breathing means extra oxygen". Comparable are those among us who are transporting someone on a vent, notice the spO2 falling & pt deteriorating, so they increase the ventilators rate... not having an understanding to the I:E ratio their pt requires.

Hyperventilation is the reduction of PaCO2. Tachypnea does not always equal hyperventilation.

Thus, if you have true hyperventilation, you do have effective ventilation as indicated by lowering the PaCO2. However, in the case of a pulmonary embolus, it may not increase the PaO2.

Manually or mechanically increasing the respiratory rate can over ventilate by decreasing the PaCO2 or increasing the pH to a dangerous level. As well, as you mentioned, the I:E ration will be shortened and even inversed which can create air trapping, over distention and cause a profound adverse effect on hemodynamics. This will be of no use to either ventilation or oxygenation.

Both the BVM and a ventilator, no matter how simple (ATV), can be very, very dangerous in undereducated hands.
 

PapaBear434

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Papa, sounds like you had one hell of an incident to deal with.

Yeah. Short version:

Kids decide to steal neighbor's car. Car gets reported stolen, and cops find it on the road. So, cops turn on lights, kids being idiots decide to run.

They are going down one of our main boulevards at almost 100 mph. Police decide it's getting kind of dicey, decide to call off the chase. Kids don't slow down, pass through the red light at another major intersection, and get slammed by a minivan. The stolen vehicle is hit hard enough on the passenger side to tear the rear axle off the car, along with the gas tank. The wheels and axle are sitting on the crosswalk on the other side of the intersection, and the entire distance between them and the car is on fire thanks to the giant pool of gasoline.

The minivan flipped seven times, and landed upside down on the front line of the folks sitting at the red light on the other side. It, too, catches fire.

Four people in the burning stolen vehicle, all under the age of 16. The two on the passenger side are pinned inside of the vehicle, but somehow managed to not be burned and the fire department got the fire out decently fast. The third person got out of the vehicle, crying to the police that she begged the driver to stop and willfully turned herself in.

The 13 year old female driver, however, gets out and tries to run. Police chase, and threaten to release the K-9. She doesn't stop, and keeps running. Police make good on their threat, and release "Raptor." Raptor makes good on his NAME, and takes the girl down and takes a good chunk of flesh out of her right thigh. She goes down screaming "BRUTALITY! POLICE BRUTALITY!"

This is all we got after we got on scene, of course. We get there, and there are more flashing lights than I have ever seen so far. The majority of the intersection is on fire, so it gives the effect of "Dante's Inferno." As said, we had three different people saying they were in charge, and a dozen telling us we should go somewhere else. We finally got our patient, the 16 year old female that was pinned in the rear. Originially, we got dispatched for the 13 year old with the dog bite.

All in all, it was an interesting night. I'm happy to say, though, that there were no deaths and the worst injuries were to one of the passengers of the stolen car. It was a broken arm, a broken leg, and a concussion.
 
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Foxbat

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Thus, if you have true hyperventilation, you do have effective ventilation as indicated by lowering the PaCO2. However, in the case of a pulmonary embolus, it may not increase the PaO2.
So basically it does not (usually) decrease PaO2 but amount of oxygen which gets to brain cells is reduced due to pH shift?
 

MSDeltaFlt

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So basically it does not (usually) decrease PaO2 but amount of oxygen which gets to brain cells is reduced due to pH shift?

Oxygenation and ventilation are two completely separate things.
 

AJ Hidell

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Oxygenation and ventilation are two completely separate things.
Too true. I took some lamewad company's pre-hire exam once, and one of the questions was to define apnea. I answered that it was the absence of spontaneous ventilation. They marked it wrong if you wrote anything except the absence of respiration. I tried to explain to their clinical coordinator that ventilation and respiration were very different things, and that respiration continues after ventilation has ceased. He wasn't buying it, and obviously I was not hired for arguing with him. :rolleyes:
 

Foxbat

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I tried to explain to their clinical coordinator that ventilation and respiration were very different things, and that respiration continues after ventilation has ceased.

That's kind of sad, especially considering the fact that even in EMT class they explain this.
 
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