When will O2 truly help?

[HERBIE1]

Herbie,

Can you please explain your rationale for the statement outlined in red please?

How is a person who is anemic going to benefit from inhaling O2? The basis of anemia is lack of red blood cells, hemoglobin is found inside the RBC, and as you know carries O2 everywhere, if you have a lack of RBC's and therefore a lack of hemoglobin carrying capacity, adding O2 is pointless. The O2 must have something to bind with to be effective.

Respectfully,

JW

Mea culpa.

Guilty of oversimplification. I was merely thinking of an undiagnosed or unknown(to us) hypoxic situation that would benefit from supplemental O2. My point was that without further diagnostics, someone COULD benefit from O2 even though they did not present with a typical hypoxia related complaint.

Edited November 13, 2009 by HERBIE1

[JPINFV]

in regards to dang near every protocol guideline, for shock or blood loss, oxygen is first line drug in suspected cases of all "Anemic Hypoxemia"

Without lab work, how do you know what the actual cause for hypoxia is unless it's blindingly obvious (like trauma)? If the patient is presenting as hypoxic, it's appropriate to provide supplemental O2 in the prehospital environment. That's different than providing it because the angels on my shoulder are whispering that the patient might be anemic, even if the patient isn't presenting as hypoxic. Additionally, as shock and hypovolemia increases, you will start to see affects on the brain and respiratory centers. Just because a patient has one condition that doesn't require a treatment (not just oxygen), doesn't mean that it can't cause other conditions that require a treatment.

Additionally, in terms of protocol, the same reason why plenty of protocols require any oxygen given to be delivered via NRB mask if possible. Poor educational standards.

[Jwade]

I did misread what CHBARE post, as it was 2 am and my ambien was already working too well...My fault...

However, the bottom line here is, going back to what HERBIE stated, taking an anemic patient and sticking O2 on them without fixing the underlying issue is going to have relatively little effect.

Just spoke to my wife, Board Certified MD ( Anesthesia). You have to fix the underlying hematocrit issue first and foremost.....You can start splitting hairs like some of the posters above have started doing, however, real world application is going to do very little to help anyone...

Good Discussion

Respectfully,

JW

Edited November 13, 2009 by Jwade

[VentMedic]

Where to start....

EMS generally does not have access to many factors like Hb (and different types), A-a, lactate level, SvO2 or even the ability to take the patient's temperature.

Anxiety, "hyperventilation": Too many unknows as to if there is a medical underlying cause. Even electrolyte imbalances or an undiagnosed diabetic situation can cause a "mood swing" or "argument" to escalate out of control and what might appear as a "simple" anxiety could be a true medical situation. Thus, the word tachypnea should be used until a further exam is done. If the patient calms with O2, it could be because of comfort or because it is improving an underlying situation that is skewing the O2 consumption or Oxyhemoglobin Dissociation Curve.

Pain Management: Does O2 improve the situation by alleviating the symptoms of increased O2 demand due to pain? Advanced practitioner should know this from critical care experience. There is now tons of lierature on this subject in Anethesia and Critical Care journals. Anyone that has worked with an ill or injured patient may see the O2 SpO2 plumment if not immediately but shortly there after if the pain issue is not treated. For EMT-Bs, treatment of pain is limited but the O2 may prevent the cascade of physiological events that occur with increase O2 demand and consumption due to pain. Once pain management is under control, O2 may not be required.

Reseach: Again as I mentioned with pain management, there is an abundance of literature on the subject. However, everyone has a different theory and for every topic I can easily find 50 articles pro something and 50 articles con. For an Etomindate thread on this forum we had almost 50 articles just for a relatively short discusssion. In the larger Neuro ICUs, you may have 18 patients with different types of "Strokes" or head injuries and with them you may have 18 different O2 recipes to follow depending on whether a neurosurgeon, neurologist, Pulmonologist or Intensivist is following. It also depends on pre-existing or co-existing illness.

Medical issues: There is now much research being done with Sepsis and many protocols run with a higher FiO2 depending on SvO2 which is again a factor that EMS providers do not have access to.

Limitations:

EMS medical directors that trained in large teaching hospitals got to see the philosophies of many different doctors managing patient in many different ICUs. Thus they also learned that one recipe may not fit all and due to limitations of training in EMS, if might be better to write protocols that error on a higher side of FiO2 rather than risk having EMT(P)s trying to figuure out the intricate details of a definitive diagnosis as it pertains to O2 consumption.

EMT(P) training in the U.S. does not give much foundation for understanding sepsis, pain, neurological or many other medical issues. Even for those using a pulse oximeter, not many understand the Oxyhemoglobin curve, A-a gradient, sepsis or other disease processes that skew the abilities of a pulse oximeter besides the few obvious one taught in EMT(P) school. Some are mystified why we are intubating someone in the ED with a 100% SpO2 on a NRBM but don't understand that the A-a gradient of 400+ mmHg is bad. We also have had disagreements with ALS IFT teams who want to wean the FiO2 by SpO2 on a sepsis patient when the SvO2 is 50%. The same for the ETCO2 when there is a relatively large PetCO2 to PaCO2 gradient.

There is also a lack of oxygen equipment education in EMS. A 4 L NC will not give the same FiO2 for someone with a MV of over 20 L/min as it will for someone with nice VTs of 500 breathing at a rate of 12. Also, the NRBM is truly not a high flow device by definition and has limitations.

Thus, EMS medical directors, knowing the variations in current medical literature and research as well as that of the EMS providers, must write for what they feel may be the safest for the patient in the short term. Even if that agency has some very highly educated providers, for every 10 with education, there may be 50 more without.

In the hospitals, we try to please everyone and I have probably 60 different protocols concerning the O2 management of various patients. This includes sepsis, ARDS, congenital anomalies, pulmonary HTN, neuro injuries, pneumothorax, post-op, pneumocephalus (including some caused by agressive CPAP on the wrong patient dx), cardiac of many types depending on pain, EF etc, and so on and so on.

I really wish I could say that this recipe is better than that recipe but as soon as I do along comes a patient that demonstrates to me and others in the medical communities a differing opinion.

[HERBIE1]

I did misread what CHBARE post, as it was 2 am and my ambien was already working too well...My fault...

However, the bottom line here is, going back to what HERBIE stated, taking an anemic patient and sticking O2 on them without fixing the underlying issue is going to have relatively little effect.

Just spoke to my wife, Board Certified MD ( Anesthesia). You have to fix the underlying hematocrit issue first and foremost.....You can start splitting hairs like some of the posters above have started doing, however, real world application is going to do very little to help anyone...

Good Discussion

Respectfully,

JW

Well, this goes back to evidence based medicine and as usual, we are at a disadvantage because our diagnostic options are limited. Without KNOWING what underlying problems are, in the case of supplemental O2, what harm could we do?

Our routine medical care for an ALS patient has always included o2, monitor, TKO IV, and a glucose check. Over the years, thanks to real world concerns like costs of glucometer test strips, we are encouraged NOT to check a sugar on every patient unless there is a suspicion(or PMH suggests) an abnormally high or low reading may be likely.

Our service is not exactly progressive, so discontinuing routine supplemental O2 because it MAY not be necessary is not likely to happen any time soon.

Can things change- of course. Look at all the changes over the years we have seen in this business. It used to be many systems required permission from medical control to even start an IV. When I first started in this business, MAST suits were standard protocol on all cardiac arrests. We no longer use them, and the reasons have been well documented. We used to be encouraged to stabilize, splint, and work up trauma patients before transport. Then came the golden hour and everything possible is done enroute to definitive care at a trauma center. I think of all the medications that have come and gone over the years like Bretylium, and aminophylline. Remember when sodium bicarb was used very early in a cardiac arrest scenario, instead of for a renal patient or for an extended resuscitation? Some changes were because better treatments came available, some were because they were simply never used, and others caused side effects that were worse than the problems you were treating.

Will the use of supplemental oxygen become less automatic? We'll see, but in the meantime, I still see no harm in it, and the potential to at the very least help alleviate a patient's fears and anxiety is reason enough to continue.

[tniuqs]

Without lab work, how do you know what the actual cause for hypoxia is unless it's blindingly obvious (like trauma)?

Clinical presentation and evaluation,and good observation in the field:

Pallor, look to mucosal membranes (pull lower eye lid and observe the color)

PMHX: say like a possible GI bleed upper or lower, sickle cell anemia,iron deficiency anemia,(a Pt. may be on iron suppliment (ask are they self medicating or are they prescribed by an MD and this some times is overlooked) heavy menstrual bleeding, in pernicious anemia (they receive Vitamin 12 on a regular basis)I could go on if you wish

http://www.emedicinehealth.com/anemia/page2_em.htm

Just spoke to my wife, Board Certified MD ( Anesthesia). You have to fix the underlying hematocrit issue first and foremost.....

hemacrit ok, lets understand that first, a pecentage of RBCs to Blood Plasma.

http://www.google.ca/search?hl=en&rlz=1C1CHMA_enCA347CA347&defl=en&q=define:hematocrit&ei=jqb9Sq-PFIa0swPXs-WdCg&sa=X&oi=glossary_definition&ct=title&ved=0CAcQkAE

So just what does your Board Certified MD wife do to correct this? If you go down the path before a clear understanding of terms well it could be a bumpy road ... just saying, again look to Vents Post re: types of Hemoglobin.

You can start splitting hairs like some of the posters above have started doing, however, real world application is going to do very little to help anyone...

I highly suspect you are referring my post split hairs or provide educational links and ask a simple question ?

See Vents post: Where to start

Ok I will do the leg work for you in regards to PaO2 this is an arterial sample, hence the a part, then analysed by a Clark electrode and actally measures the partial pressure of oxygen dissolved in the blood plasma a linear and direct relationship is made.(see chbare equation its the .0003 part)

Then with all the factors ODC calculated and value is determined

IN some ways bedside Pulse oximetry used to trending device is a extremely valuable tool, even in the light of an anemic hypoxia.

http://www.google.ca/search?hl=en&rlz=1C1CHMA_enCA347CA347&q=pulse+oximetry+measures&meta=&aq=3&oq=pulse+oximetry

http://www.google.ca/search?hl=en&rlz=1C1CHMA_enCA347CA347&q=pulse+oximetry&btnG=Search&meta=&aq=f&oq=

One of the biggest concerns of mine In EMS is the serious misunderstanding between oxygenation and ventilation. So a little side bar, 2 years ago now RNs treated my mother post op major GI surgery, and even though I attempted to explain the difference of hypoventilation and oxygenation, studies indicate post op geriatric patient that supplemental O2 may increase mortality morbidity ... It did in My Mothers case, unrecognized Hypoventilation (but Pulse oximetry by their protocol, and all was good ) this lead to pre renal failure and my mother died, yes anecdotal but now clearly backed by EBM, btw the Board Certified MD Anesthesia did contribute in passing, urine output during surgery and post op (this on a RENAL unit to boot)then oxygen absorbortion atelectasis a post mortum finding. The RN said they were just following (protocol post surgery orders)

(I was not in the employment as an RRT in that facility) the RNs have since received a very serious lecture since that time by the manager of respiratory department, the protocol has now been CHANGED, Respiratory Therapy department is now consulted.

In part thanks to VentMedic an PM's I will always be in Vents Debt besides having a personal relashonship with the associate professor of ICU did not hurt either.

There are much controversy now with researchers in regards to High levels of O2 vs Low levels in the CHF patient, just what I do is in cases of CHF and in Pulmonary odeama (when no anemia suspected) is watch the pulse ox trends.

And as Ventmedic just touched upon many other areas, it boils down to this EMS initiates O2 therapy, RRTs then wean patients off O2, with all the hospital toys we get to play with: YES O2 is a toxic gas but not over the very short time in contact in the field, it has not been proven to be harmful (in vast majority of cases) that said the jury is not completely in lots of research to do yet.

I did misread what CHBARE post, as it was 2 am and my ambien was already working too wel

Did you note the time of my post? I get crabby when I am sleep deprived.

Oh the O2 treats Nausea? Nope I disagree the EMS provider in that case used the gift of the GAB, body language, and confidence this relieved anxiety .... the placebo effect is huge and a tool in the EMS provider should NEVER forget.

Anecdotally I have had some patients that have very seriously survived because they were convinced that they would, comments like hey I have seen way worse and their still walking and causing grief.

One case comes to mind an elderly Woman on every Cardiac Med Know to man, in flash Pulmonary odeama ... 5 stents, LEF about 12% so I was honest with her, things are not looking great here: Her comment to me:

Ah don't worry about me I will live longer just to piss some people OFF and she DID

cheers

[HERBIE1]

To echo what tniugs- and I- said, lacking definitive evidence that supplemental O2 does any harm to the average prehospital patient, I think the placebo effect is HUGE. A person calls 911 for help, and assumes we can help them, or at least help ease their fears. Not every patient will have a dramatic turnaround like a narcotic OD, a reversal of hypoglycemia, or treatment for chest pain or pulmonary edema. Think about how often people ask how their BP is. Diagnostically it may have nothing to do with their situation, but it's something that most people understand. Think about how often people ask us what we think is going on with them. (No, we don't offer a diagnosis, but many times we can alleviate concerns with simple things like a kind word, a reassurance, or offer a possible, less serious reason for their symptoms.)

If we tell them the O2 should help their nausea, anxiety, weakness, etc, then often times they accept it, calm down, and feel better. They arrive at the ER hopefully in a slightly better state physically and emotionally than when we arrived. The ER takes over and provides definitive care, but with all our fancy toys, medications, and training, I think too often we forget that the little things are what patients and their family remember about EMS. The end result is what counts, and the patient couldn't care less how many initials you have behind your name, that you just finished training on a new piece of equipment, or just reupped your ACLS certification. They simply want to feel better, and isn't that what this is all about? We are the first step of a continuum of care and I think that starting off on the right foot is an important part of feeling better.

Several people have mentioned the mindset of a patient, and I agree that there are some people who are simply just too stubborn to die. We've all had the patients who defy all odds and should not be walking this earth- they conquer and recover from seemingly impossible situations time after time. We also have the people who succumb to illnesses and problems that are minor by comparison.

I had a regular lady around 60 years old who had diabetes, CHF, MI's, CAD, one leg amputee- and on a drug store full of meds. Every several weeks she would call, and we would find her in the same situation- standing on one leg with her head in the freezer(she was convinced this made her feel better), with audible rales heard down the hall of her building, struggling to breathe. I intubated her 3 times(Did not have CPAP), and treated her with medications at least a dozen more. Most of the time she was breathing normally by the time we reached the ER and she always thanked us profusely. Her heart finally did give out, but from what I was told, it was actually sepsis that did her in. On several of her close calls, she did indeed tell us she was too ornery to die yet, and that she was simply not yet ready. We believed her.

[Jwade]

Clinical presentation and evaluation,and good observation in the field:

Pallor, look to mucosal membranes (pull lower eye lid and observe the color)

PMHX: say like a possible GI bleed upper or lower, sickle cell anemia,iron deficiency anemia,(a Pt. may be on iron suppliment (ask are they self medicating or are they prescribed by an MD and this some times is overlooked) heavy menstrual bleeding, in pernicious anemia (they receive Vitamin 12 on a regular basis)I could go on if you wish

http://www.emedicinehealth.com/anemia/page2_em.htm

hemacrit ok, lets understand that first, a pecentage of RBCs to Blood Plasma.

http://www.google.ca/search?hl=en&rlz=1C1CHMA_enCA347CA347&defl=en&q=define:hematocrit&ei=jqb9Sq-PFIa0swPXs-WdCg&sa=X&oi=glossary_definition&ct=title&ved=0CAcQkAE

So just what does your Board Certified MD wife do to correct this? If you go down the path before a clear understanding of terms well it could be a bumpy road ... just saying, again look to Vents Post re: types of Hemoglobin.

I highly suspect you are referring my post split hairs or provide educational links and ask a simple question ?

See Vents post: Where to start

Ok I will do the leg work for you in regards to PaO2 this is an arterial sample, hence the a part, then analysed by a Clark electrode and actally measures the partial pressure of oxygen dissolved in the blood plasma a linear and direct relationship is made.(see chbare equation its the .0003 part)

Then with all the factors ODC calculated and value is determined

IN some ways bedside Pulse oximetry used to trending device is a extremely valuable tool, even in the light of an anemic hypoxia.

http://www.google.ca/search?hl=en&rlz=1C1CHMA_enCA347CA347&q=pulse+oximetry+measures&meta=&aq=3&oq=pulse+oximetry

http://www.google.ca/search?hl=en&rlz=1C1CHMA_enCA347CA347&q=pulse+oximetry&btnG=Search&meta=&aq=f&oq=

One of the biggest concerns of mine In EMS is the serious misunderstanding between oxygenation and ventilation. So a little side bar, 2 years ago now RNs treated my mother post op major GI surgery, and even though I attempted to explain the difference of hypoventilation and oxygenation, studies indicate post op geriatric patient that supplemental O2 may increase mortality morbidity ... It did in My Mothers case, unrecognized Hypoventilation (but Pulse oximetry by their protocol, and all was good ) this lead to pre renal failure and my mother died, yes anecdotal but now clearly backed by EBM, btw the Board Certified MD Anesthesia did contribute in passing, urine output during surgery and post op (this on a RENAL unit to boot)then oxygen absorbortion atelectasis a post mortum finding. The RN said they were just following (protocol post surgery orders)

(I was not in the employment as an RRT in that facility) the RNs have since received a very serious lecture since that time by the manager of respiratory department, the protocol has now been CHANGED, Respiratory Therapy department is now consulted.

In part thanks to VentMedic an PM's I will always be in Vents Debt besides having a personal relashonship with the associate professor of ICU did not hurt either.

There are much controversy now with researchers in regards to High levels of O2 vs Low levels in the CHF patient, just what I do is in cases of CHF and in Pulmonary odeama (when no anemia suspected) is watch the pulse ox trends.

And as Ventmedic just touched upon many other areas, it boils down to this EMS initiates O2 therapy, RRTs then wean patients off O2, with all the hospital toys we get to play with: YES O2 is a toxic gas but not over the very short time in contact in the field, it has not been proven to be harmful (in vast majority of cases) that said the jury is not completely in lots of research to do yet.

Did you note the time of my post? I get crabby when I am sleep deprived.

Oh the O2 treats Nausea? Nope I disagree the EMS provider in that case used the gift of the GAB, body language, and confidence this relieved anxiety .... the placebo effect is huge and a tool in the EMS provider should NEVER forget.

Anecdotally I have had some patients that have very seriously survived because they were convinced that they would, comments like hey I have seen way worse and their still walking and causing grief.

One case comes to mind an elderly Woman on every Cardiac Med Know to man, in flash Pulmonary odeama ... 5 stents, LEF about 12% so I was honest with her, things are not looking great here: Her comment to me:

cheers

OK, First, I really do NOT need any lecture on from an RRT on physiology, as I have an entire 4 years of undergrad dedicated to this. Second, I am well educated in all of the modalities in which you took such time and effort to belittle me with....I really know all those nice little calculations and while certainly useful in an ICU setting, they are pretty pointless in the majority of EMS calls.....

I was initially speaking from a very basic point of view, and in the scenario HERBIE presented, the H& H ideally should be dealt with first. I even ran this thread by the SICU Trauma Surgeon / Intensivist today, and he said, " 1. The Placebo effect is unknown, 2. Eventually you are going to HAVE to fix the H&H regardless of what other modalities you try."

While, I have no doubt from your well written information you are highly educated on the subject, and as an RRT, I would hope so, however, I think I am going to stick with the advice of the SICU Trauma Surgeon and my wife who used to run a Thoracic ICU. Sorry....Will just have to agree to disagree. :-)

My respects for the loss of your mother. Never easy.

Respectfully,

JW

[Brandon Oto]

This is awesome and informative, guys, but I'm still interested mainly in the original question. I guess we've all agreed that there can be a strong placebo effect attached to any use of O2; that said, there will still be cases where it's also physiologically beneficial, and those where it's not.

My treatment for anemia is a bolus of definitive care

[mobey]

This is awesome and informative, guys, but I'm still interested mainly in the original question.

Sorry buddy, but this is what starting a thread is all about.

Each person has given you an answer/opinion and are attempting to back it up.

Sit back, read, indulge, and lap up all the good info that is being discussed.