When will O2 truly help?

[HERBIE1]

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

There will always be folks eager to show their expertise in a certain area. The thing about a diverse group as we have here is that everyone has their niche and will gladly share their sometimes extensive knowledge of a particular area.

Nice to know- sure.

Informative- absolutely.

Practical and appropriate for this context? Not always.

Just take what you need from the discussion, and if your question still isn't answered after all the sword rattling, ask it again. Threads frequently get side tracked.

[melclin]

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.

I'm sorry to hear that. It raises in interesting point for me, a student who is still wrapping their heads around these concepts. I was reading a chapter of Clinical Anesthesia (as all 21 year old university students should be doing during their holidays ) this morning and I came across the following passage, "However, a patient who is receiving minimal supplemental oxygen and has an acceptable oxygen saturation may have significant undetected alveolar hypoventilation". Other than using our knowledge of the particular problem that our pt presents with to infer that there may be a ventilation issue, is there a way of ascertaining this in the pre-hospital context (capnography?)? Its probably not a practical point considering that it may be enough for us just to keep their oxygen saturation up during the short time we see them (no capnography our AP trucks (our BLS), we don't even have pulse ox sometimes, but that's changing), but I'm interested none the less. Respiratory physiology is glossed over pretty briefly in my degree, which I don't agree with.

Am I correct in assuming that the issue with masking hypo-ventilation with higher Fi02 is to do with reduced excretion of CO2 --> respiratory acidosis?

[VentMedic]

Other than using our knowledge of the particular problem that our pt presents with to infer that there may be a ventilation issue, is there a way of ascertaining this in the pre-hospital context (capnography?)?

The situation described by Tnuigs is something we are concerned about in the hospital and especially post op. Even at that, standing orders from surgery usually say O2 for 24 hours. In my role in the hospital, unless there is a sepsis or wound care issue, I can override that order with those from my medical director to make that O2 go away by just following a few guidelines for the various surgical patients. Thus, in many hospitals, RT knows about every O2 patient in the hospital. RNs are sometimes too busy for the old fashioned cough and deep breathe exercising of their patients and would rather put O2 on. Whenever I find a patient with lower SpO2s and I know some of the history, I see what their SpO2 will do if they take a couple deep breaths with a slight hold. That may also tell me a little about what I'm dealing with for the next step in their pulmonary or cardiac treatment.

Some patients you see in the field are chronic hypoventilators. Without any lung disease they retain CO2 and buffer for high CO2. History and physical assessment can often tell you if they may have a tendency to hypoventilate. Some will see a sleep apneas machine and assume it is for OSA when it might be a bilevel (BiPAP) machine for hypoventilation. You can ask the patient "do you have a tendency to not breath deeply at night" or "do you snore or obstruct". Is your machine straight CPAP or does it offer another pressure when you breathe in?"

Is the patient obese? Do they have a history of paralysis or loss of muscle strength from something like Gullian Barre? Do they have ALS or MS?

You can watch their tidal volume movement and respiratory rates. Some breathe shallow and may have a higher RR to give an overall decent Minute Volume. At sleep, their RR may slow and their CO2 rises. That is why I caution people not to use the term "hyperventilate" when assessing a patient with a higher than normal RR. Tachypnea and tidal volume observations should be noted instead of just stating "hyperventilation" when the PaCO2 may actually be 70 mmHg.

These patients I am a little more anxious to get their PaO2 back to normal once the underlying are identified. Remember the difference between Aveolar ventilation (PAO2) and that which makes it to the blood stream (PaO2) to give us a view of the A-a gradient. If they do require prolonged O2 therapy and it isn't just because of a pulmonary disease process like PNA which lowers the PaO2 or even if it is, this patient may need BiPAP during their time on the oxygen. But again, this will be for an extended period of time.

Often in the ambulance and ED, the SpO2, history of past and acute illness/injury, breath sounds and physical assessment for work of breathing will give you some direction to follow until diagnostic tests (and philosophy of the specialist attending MD) steer the course.

[VentMedic]

There will always be folks eager to show their expertise in a certain area. The thing about a diverse group as we have here is that everyone has their niche and will gladly share their sometimes extensive knowledge of a particular area.

Nice to know- sure.

Informative- absolutely.

Practical and appropriate for this context? Not always.

Just take what you need from the discussion, and if your question still isn't answered after all the sword rattling, ask it again. Threads frequently get side tracked.

To Brandon Oto,

Your questions:

But when will it actually help? I'm curious in two things --

1. For a given condition, in your PERSONAL EXPERIENCE, have you witnessed either ALLEVIATION OF SYMPTOMS or IMPROVED OUTCOMES following the administration of oxygen? This is obviously just anecdotal, but it's the best we're going to do in many cases.

2. For a given condition, have you seen any rigorous research that supports or denies either of the above?

Your questions can not be simply answered with a yes or no. The subject of oxygen and the many patient care applications is a very broad subject. It may require some intense physiological explanations complete with formulas to express the many different conditions one could encounter with patients. It is not about just boasting knowledge and most of what has been explained so far is basic Respiratory 101 or what you might find in a decent college level A&P class.

This is not about whose "sword has a bigger rattle". The posts are from people with many levels of education and expertise as well as many years of EMS experience to show you there is no one recipe fits all patients when it comes to oxygen therapy.

I have advanced college degrees in subjects pertaining to oxygen and it is just enough education to show me how much I still don't know about the subject. It would be a full time job just to read all the latest research about oxygen as it is used in various specialties and disease processes.

Unlike the MAST which was a man made device intended to serve one purpose, O2 exists in the air and affects many organs at a physiological level. When the body is deprived of it at the alveolar or tissue level, changes to occur. However, as others have demonstated, without certain diagnostic tests you may not know the extent the body is being deprived. The intent is generally to keep the PaO2 of the body at a normal level but it may take a higher FiO2 to do that depending on the disease processess and cardiac function of the patient.

Even in the hospital, we know the patient should be off an FiO2 of 1.0 and below 0.60 (or 0.50) depending on which studies) before 24 hours. Unfortunately if a patient is also septic, the rules of weaning the FiO2 may take a backseat to seeing the tissues get oxygen. However, another septic patient may respond quickly to fluids and other therapies quickly and we can continue with weaning the FiO2. But, some patients with ARDS such as what we are seeing with the H1N1 flu may be on very high FiO2 with serious technology attached for 1 - 3 weeks. Those that survive may have some reduced pulmonary function but it will from the scarring caused by the disease. The extensiveness of it may prevent us from finding out what the O2 did to the lungs unless a biopsy is done either living or post mortem.

For the research and literature, there are many, many specialties with a vested interest in the subject of oxygen. Even with good theories about the right way to use O2, the patient's body may dictate another way. Hospitals do have the luxury of knowing the disease processes and run O2 protocols bases on those diseases such as pulmonary hypertension and sepsis.

Thus, in the short term, assessment is key. Once you take more classes to understand the disease processes and the body's physiology, you will be able to justify why you did or did not use O2 once your level allows you to make that judgement. However, even if you do advance, your agency's protocols may have to reflect the weakest link or the minimally educated. That also includes some Paramedic level agencies in the U.S.

[Brandon Oto]

That's great, Vent. And I do appreciate the complexities involved with everyone's favorite little diatomic inhalant. But pending my training as an RT, if you hand me a patient, I still have to either give them oxygen or not; the pathophysiology involved may be largely over my head, but there's still only two options available to me. Can't we reduce these things to a somewhat easier set of principles or rules of thumb based on the brief time the patient will be under my care -- i.e. in the 8-15 minutes it's going to take me to back into the ER, I'd like to help some, but I probably don't need to work any miracles... just palliate a little. Or are you advocating the old everyone-gets-it strategem as the safest scheme for a low-level prehospital provider with a limited period of patient contact?

[HERBIE1]

To Brandon Oto,

Your questions:

Your questions can not be simply answered with a yes or no. The subject of oxygen and the many patient care applications is a very broad subject. It may require some intense physiological explanations complete with formulas to express the many different conditions one could encounter with patients. It is not about just boasting knowledge and most of what has been explained so far is basic Respiratory 101 or what you might find in a decent college level A&P class.

This is not about whose "sword has a bigger rattle". The posts are from people with many levels of education and expertise as well as many years of EMS experience to show you there is no one recipe fits all patients when it comes to oxygen therapy.

I have advanced college degrees in subjects pertaining to oxygen and it is just enough education to show me how much I still don't know about the subject. It would be a full time job just to read all the latest research about oxygen as it is used in various specialties and disease processes.

Unlike the MAST which was a man made device intended to serve one purpose, O2 exists in the air and affects many organs at a physiological level. When the body is deprived of it at the alveolar or tissue level, changes to occur. However, as others have demonstated, without certain diagnostic tests you may not know the extent the body is being deprived. The intent is generally to keep the PaO2 of the body at a normal level but it may take a higher FiO2 to do that depending on the disease processess and cardiac function of the patient.

Even in the hospital, we know the patient should be off an FiO2 of 1.0 and below 0.60 (or 0.50) depending on which studies) before 24 hours. Unfortunately if a patient is also septic, the rules of weaning the FiO2 may take a backseat to seeing the tissues get oxygen. However, another septic patient may respond quickly to fluids and other therapies quickly and we can continue with weaning the FiO2. But, some patients with ARDS such as what we are seeing with the H1N1 flu may be on very high FiO2 with serious technology attached for 1 - 3 weeks. Those that survive may have some reduced pulmonary function but it will from the scarring caused by the disease. The extensiveness of it may prevent us from finding out what the O2 did to the lungs unless a biopsy is done either living or post mortem.

For the research and literature, there are many, many specialties with a vested interest in the subject of oxygen. Even with good theories about the right way to use O2, the patient's body may dictate another way. Hospitals do have the luxury of knowing the disease processes and run O2 protocols bases on those diseases such as pulmonary hypertension and sepsis.

Thus, in the short term, assessment is key. Once you take more classes to understand the disease processes and the body's physiology, you will be able to justify why you did or did not use O2 once your level allows you to make that judgement. However, even if you do advance, your agency's protocols may have to reflect the weakest link or the minimally educated. That also includes some Paramedic level agencies in the U.S.

See what I mean, Brandon?

[tniuqs]

To the OP:

1. For a given condition, in your PERSONAL EXPERIENCE, have you witnessed either ALLEVIATION OF SYMPTOMS or IMPROVED OUTCOMES following the administration of oxygen? This is obviously just anecdotal, but it's the best we're going to do in many cases.

The IMPROVED OUTCOMES in the very short time that one attends to this or that patient in EMS is going to be VERY difficult to prove or disprove as most studies are "To Door" discharge, involving a huge cascade of Health Care Providers.

That's great, Vent. And I do appreciate the complexities involved with everyone's favorite little diatomic inhalant. But pending my training as an RT, if you hand me a patient, I still have to either give them oxygen or not; the pathophysiology involved may be largely over my head, but there's still only two options available to me. Can't we reduce these things to a somewhat easier set of principles or rules of thumb based on the brief time the patient will be under my care -- i.e. in the 8-15 minutes it's going to take me to back into the ER, I'd like to help some, but I probably don't need to work any miracles... just palliate a little. Or are you advocating the old everyone-gets-it strategem as the safest scheme for a low-level prehospital provider with a limited period of patient contact?

To answer the question for the BASIC look to the pulse ox (if you have one) If you improve saturation you doing something for whatever the "slot" the patient one believes, ie say a COPD, with a Cardiac PmHx and throw in a community acquired pneumonia.

But then withholding O2, with some study in hand and you may find your head in a guillotine for not following accepted practice, just saying.

2. For a given condition, have you seen any rigorous research that supports or denies either of the above?

http://www.google.ca/search?hl=en&rlz=1C1CHMA_enCA347CA347&q=controversy+in+Oxygen+therapy+scholarly+studies&btnG=Search&meta=&aq=f&oq=

As Vent notes: It would be a full time job just to read all the latest research about oxygen as it is used in various specialties and disease processes.

Then introducing the PLACEBO effect, a hotly contested subject in latest issues of NEJM and the conclusions draw from meta studies vs some of the more dated studies that state empirically that this is even measurable. One certainly opens up a can of worms for the ethics types as delivery of Oxygen Therapy has never been studied, just medication(s)

In regards to sword rattling, I provided for you as requested an anecdotal comment AND provided as much information concerning Pulmonary Physiology and the physics behind the rationale. I am and will continue to throw a gauntlet down in the spirit of an interesting debate, but taking it to my friend said level and emotional level ... FAIL.

I do not have a degree I just make stuff up

Mixing an "ethical dilemma" and the asking for "anecdotal comments" and toss in "human physiology and physics" you are going to get more conjecture than science.

http://en.wikipedia.org/wiki/Ethical_dilemma

[Jwade]

To the OP:

The IMPROVED OUTCOMES in the very short time that one attends to this or that patient in EMS is going to be VERY difficult to prove or disprove as most studies are "To Door" discharge, involving a huge cascade of Health Care Providers.

To answer the question for the BASIC look to the pulse ox (if you have one) If you improve saturation you doing something for whatever the "slot" the patient one believes, ie say a COPD, with a Cardiac PmHx and throw in a community acquired pneumonia.

But then withholding O2, with some study in hand and you may find your head in a guillotine for not following accepted practice, just saying.

http://www.google.ca/search?hl=en&rlz=1C1CHMA_enCA347CA347&q=controversy+in+Oxygen+therapy+scholarly+studies&btnG=Search&meta=&aq=f&oq=

As Vent notes: It would be a full time job just to read all the latest research about oxygen as it is used in various specialties and disease processes.

Then introducing the PLACEBO effect, a hotly contested subject in latest issues of NEJM and the conclusions draw from meta studies vs some of the more dated studies that state empirically that this is even measurable. One certainly opens up a can of worms for the ethics types as delivery of Oxygen Therapy has never been studied, just medication(s)

In regards to sword rattling, I provided for you as requested an anecdotal comment AND provided as much information concerning Pulmonary Physiology and the physics behind the rationale. I am and will continue to throw a gauntlet down in the spirit of an interesting debate, but taking it to my friend said level and emotional level ... FAIL.

I do not have a degree I just make stuff up

Mixing an "ethical dilemma" and the asking for "anecdotal comments" and toss in "human physiology and physics" you are going to get more conjecture than science.

http://en.wikipedia.org/wiki/Ethical_dilemma

Tniuqs,

Well stated, Excellent reply..

I do not have a degree(s) either, However, I did sleep at a holiday inn express last night! That has to count for something right?

Respectfully,

JW

[Chief1C]

I find it helpful for headaches, esp. those caused by a 'hangover'. Using ones own supply, of course, not discovering while on duty, et al.

[mobey]

I find it helpful for headaches, esp. those caused by a 'hangover'. Using ones own supply, of course, not discovering while on duty, et al.

A litre or more of RL is also pretty good for a hangover since dehydration is usually a key factor in feeling like $hit.

Put on a nasal cannula and hang a litre and a half, and you'll be good to go.

Naaa...... Just kidding... I'd never do that!