Too Much Oxygen? hmmmm

[JPINFV]

Treat your patient not the machine.

I dont care if the pulse ox tells me its 1000 percent. If my patient is having a hard time breathing or showing cyanosis anywhere. They shall be getting o2 from me.

Side note: Besides being cold, poor circulation, and co2 poisoning. Does Shock cause an inaccurate reading? Or does that go along with poor circulation.

I agree, to a point. An O2 saturation is simply a measurement of the percent of hemoglobin bound and the question needs to be asked, when evaluating the number, is "Why?" If the patient is at 95% because the patient is compensating, then yes, oxygen is indicated. If the patient is at 95% and breathing normally, then oxygen really isn't indicated. If the patient is breathing normally and hypoxic, then unless there's a reason to doubt the pulse ox, oxygen is indicated.

The problem is that a O2 saturation is not just a number to write down. The breathing status is not just some check boxes to mark. Just because a pulse ox is 100% and the patient is breathing 40 breaths per minute does not mean that the saturation is not 100%. This isn't about treating the patient vs treating the assessment tool. It's about using an assessment tool to add a piece to the puzzle. Understanding what that piece is, where it belongs, and what it tells you is infinitely more important than any discussion about treating the patient vs treating the tool. In fact, if you understand what it's telling you, you won't need a cliche to use it properly.

Shock is poor circulation on a systemic level.

 

[jrm818]

Treat your patient not the machine.

I dont care if the pulse ox tells me its 1000 percent. If my patient is having a hard time breathing or showing cyanosis anywhere. They shall be getting o2 from me.

Based on what? Do you/Does anyone have any evidence of harm from witholding supplemental O2 in a patient with a high O2 saturation? Because there is good evidence of harm from administration of supplemental O2 even in some settings of SOB (COPD exacerbation specifically).

 

[Journey]

...and, giving the topic of this thread and oxygen administration, you can make an argument that the near dead who have a good O2 saturation with no dyspnea need supplemental oxygen? The indication for supplemental oxygen is not "sick patient." A patient can be sick, even terminally, and not need supplemental oxygen.

You are going to take that pulse ox number as your indication for O2?

Terminal patients may also have other medications on board which blunt the symptoms of hypoxia which is what hospice specializes in. Their goal is to make the patient's dying body forget about how its tissues are experiencing hypoxia regardless of what number your pulse oximeter states. In the terminal patient it may not be an issue of "not needing oxygen" but rather reaching a point where you must realize the tissues can no longer utilize the oxygen and other options through pharmacology work better to make the patient comfortable.

You also have to define "sick" patient in terms of actual disease processes before you can determine the appropriate oxygenation. A patient with a seasonal cold might look sick but I wouldn't classify them the same as someone who looks sick from sepsis. You must learn some of the basic priniciples of the disease processes and a little pathophysiology.

 

[Journey]

Based on what? Do you/Does anyone have any evidence of harm from witholding supplemental O2 in a patient with a high O2 saturation?

Yes which is why we have SvO2 monitoring in the ICUs and StO2 monitoring in the EDs especially for trauma.

Because there is good evidence of harm from administration of supplemental O2 even in some settings of SOB (COPD exacerbation specifically).

COPD? Hopefully you are not referring to the "hypoxic drive".

 

[325Medic]

Yes which is why we have SvO2 monitoring in the ICUs and StO2 monitoring in the EDs especially for trauma.



COPD? Hopefully you are not referring to the "hypoxic drive".

Too much o2 can react with oxygen free radicles causes your cells / mitrochronidria to essentially destroy causing cell death and death of cellular resp. It goes much further that this though. Thats why during codes and STEMI and stroke for that matter, they say tritate to a sat of 94-99. It has to do with the oxygentation curve.

325.

 

[JPINFV]

You are going to take that pulse ox number as your indication for O2?

As a factor among many. It's certainly more practical and scientific than having the indication for a NRB mask be "ambulance."

Terminal patients may also have other medications on board which blunt the symptoms of hypoxia which is what hospice specializes in. Their goal is to make the patient's dying body forget about how its tissues are experiencing hypoxia regardless of what number your pulse oximeter states. In the terminal patient it may not be an issue of "not needing oxygen" but rather reaching a point where you must realize the tissues can no longer utilize the oxygen and other options through pharmacology work better to make the patient comfortable.

Hospice patients are also cared for by a team of health care providers who's specialized in hospice care and have more tools at their disposal to determine how much, if any, supplemental oxygen is necessary. I find it hard to believe that either all hospice patients are always a supplemental, or that these teams are hopelessly incompetent until an EMT comes along and says, "Well, I've got an ambulance and an ambulance is an indication for a NRB at 15 L/min, therefore this patient gets oxygen."

You also have to define "sick" patient in terms of actual disease processes before you can determine the appropriate oxygenation. A patient with a seasonal cold might look sick but I wouldn't classify them the same as someone who looks sick from sepsis. You must learn some of the basic priniciples of the disease processes and a little pathophysiology.

I believe you're misunderstanding the concepts of "indication" and "contraindication."

So, are you suggesting that all patients need a NRB mask at 15 L/min regardless of presentation and assessment tools is a valid thought process and that EMS is incapable of determining how much, if any, supplemental oxygen is needed?

 

[Journey]

As a factor among many. It's certainly more practical and scientific than having the indication for a NRB mask be "ambulance."


Hospice patients are also cared for by a team of health care providers who's specialized in hospice care and have more tools at their disposal to determine how much, if any, supplemental oxygen is necessary. I find it hard to believe that either all hospice patients are always a supplemental, or that these teams are hopelessly incompetent until an EMT comes along and says, "Well, I've got an ambulance and an ambulance is an indication for a NRB at 15 L/min, therefore this patient gets oxygen."


I believe you're misunderstanding the concepts of "indication" and "contraindication."

So, are you suggesting that all patients need a NRB mask at 15 L/min regardless of presentation and assessment tools is a valid thought process and that EMS is incapable of determining how much, if any, supplemental oxygen is needed?

There are more ways to deliver oxygen than just a 15 L NRB mask. You can given as little as a half a liter in some cases by a nasal cannula or a special mask. EMT training is very limited and probably time does not allow you to be taught all the various methods of oxygen delivery.

If a patient goes into Comfort Care in the hospital, we no longer do pulse ox checks. It will be determined that the O2 and medication relieving pain and the symptoms of dysnpnea will be titrated to patient comfort. In many situations, we will no longer chase the patient with O2 but will rely on the medication to make them comfortable. Unfortunately some EMTs are required to do pulse ox checks or oxygen is the only medication they have for comfort during transport which is why the patient may also be placed on a NRB mask. Some EMTs do have a difficult time understanding how we can allow a patient with an SpO2 of 70 to be just on a 2 L NC regardless of being in a comfortable state when they are called to transport a patient home or to a hospital facility and will call hospital staff incompetent.

There are some medical situations where O2 at 100% is indicated. This is also why we utilize other tools such as SvO2, StO2 and lab values and not just a pulse oximeter. Initially there are very few contraindications to delivering oxygen to a patient. However, you should be educated to understand the body's response to O2 for V/Q mismatch and pulmonary vasoconstriction and respond with the appropriate treatment which in some cases could be more oxgen. For long term consequences, it will depend on the length of time the patient is on the O2 and method of delivery. Yes, an ambulance can do damage by misunderstanding and misusing PEEP or not being prepared for an asthmatic to repond with a drop in SpO2 initially when albuterol is given along with O2 or when CO2 does rise. But, this is more on the training and education of the provider rather than all oxygen is bad.

On an ambulance especially at the EMT-B level you will not have access to all of this data nor will you be able to pharmacologically make someone comfortable who is dyspneic so you may have to go with what you have which is oxygen.

 

[Journey]

Too much o2 can react with oxygen free radicles causes your cells / mitrochronidria to essentially destroy causing cell death and death of cellular resp. It goes much further that this though. Thats why during codes and STEMI and stroke for that matter, they say tritate to a sat of 94-99. It has to do with the oxygentation curve.

325.

How long do you plan on keep the patient inside an ambulance? Do you there can be some cerebral situations where O2 by mask at 100% is indicated? Do you withhold oxygen to a patient that needs it now to prevent immediate damage to organs for something that might start to happen 24 - 72 hours later?

Are you working adult codes on 21% or have a way to accurately titrate O2 to a specific concentration in an ambulance that is not a Specialty unit?

What Oxygen Curve are you referring to? The Oxyhemoglobin Dissociation curve should how you can have a pulse ox of 94% but very different PaO2 values for each patient depending of the factors that shift the curve.

 

[usafmedic45]

I was in a nursing home once and this nurse was talking to another nurse about this lady who was hooked up to a oxygen concentrator via nasal cannula. This lady was alittle loopy but since she was old I figured her brain was fried. Long story short the nurse went on to say she was alittle crazy because theres so much oxygen going to her brain she was losing it.

Under normal atmospheric pressure, that's not going to happen. I mean no offense here, but in my experience both as an EMS provider and a respiratory therapist, the amount most non-ICU nurses know about oxygen therapy would barely fill a shot glass. What they understand about it would usually fill an insulin syringe.

I looked at myself and always thought 02, Oxygen was like chicken noodle soup was when your sick.

Nope. Unless there is specifically a problem with oxygenation, there's no evidence to support push more O2 at them. In fact, there's some evidence that it's harmful. And, no, it has nothing to do with the "hypoxic drive".

How can you get enough 02 into you?

Hyperbaric chamber or diving while breathing pure O2.

I know some what about people being oxygen dependency but still.

How so?

When I became a nurse even I don't know everything. Once you know everything in this field hang up your scrubs and stethoscope.

That's a good attitude. It seems you need to know a bit more about O2 therapy. I'm happy to help you with that.

Do you there can be some cerebral situations where O2 by mask at 100% is indicated? Do you withhold oxygen to a patient that needs it now to prevent immediate damage to organs for something that might start to happen 24 - 72 hours later?

Care to show some evidence to back up the "you need 100% O2 for adequate oxygenation" claim? It's a common mistake to believe that "high flow O2" is needed to "guarantee" a good outcome.

Because there is good evidence of harm from administration of supplemental O2 even in some settings of SOB (COPD exacerbation specifically).

You want to expound on that? Like someone said, let's not further spin the yarn of 'hypoxic drive'.

 

[jrm818]

COPD? Hopefully you are not referring to the "hypoxic drive".

You want to expound on that? Like someone said, let's not further spin the yarn of 'hypoxic drive'.

.

I should have clarified. I was questioning whether even "SOB" is adequate as an indication for O2 without exception. I would expect (rightly so?) to be burned as a heretic if I was talking about the hypoxic drive. I really meant O2 induced hypercarbia and acidosis (and eventually...post EMS care... direct lung injury, as has been mentioned). The only EMS study that I am aware of that examined this issue found that there was a pretty significant effect on mortality:

http://emtlife.com/showthread.php?t=20513
http://www.bmj.com/content/341/bmj.c5462.abstract

 

[Journey]

Care to show some evidence to back up the "you need 100% O2 for adequate oxygenation" claim? It's a common mistake to believe that "high flow O2" is needed to "guarantee" a good outcome.

It is also a common mistake to believe a 15 L NRB mask is "high flow O2".

You must understand a few terms like hyperoxyia which is determined by an ABG (Arterial Blood Gas) not SpO2 and A-a Gradient which is the the difference between oxygen going into the alveoli and that which is in the artery. You can have an SpO2 of 100% and even with being on 100% oxygen, your PaO2 might just fall into the range on the Oxyhemoglobin Dissociation curve.

The oxyhemoglobin dissociation curve relates oxygen saturation (SO2) and partial pressure of oxygen in the blood (PO2), and is determined by what is called hemoglobin's affinity for oxygen,that is, how readily hemoglobin acquires and releases oxygen molecules from its surrounding tissue.

Hyperoxia is defined by many studies as being over 300 mmHg. If patients have multiple disease processes going on, 300 mmHg might be difficult to achieve even on 100% oxygen or just a 15 L NRB mask.

For some neuro and sepsis patients we will run the PaO2 closer to 90 - 100 mmHg rather than the lower 70 - 90 mmHg or 60 - 80 mgHg for some lung diseases. Some neuro patients will have cerebral vasospasms which require a close attention to FiO2 and fluids. For other medical patients we will monitor SvO2 or StO2 which involves tissue oxygenation.

Does this mean all patients need a 15 L NRB mask? No. But as an EMT do you really know all the disease processes or have enough diagnostic data to make a blanket statement?

 

[Journey]

.

I should have clarified. I was questioning whether even "SOB" is adequate as an indication for O2 without exception. I would expect (rightly so?) to be burned as a heretic if I was talking about the hypoxic drive. I really meant O2 induced hypercarbia and acidosis (and eventually...post EMS care... direct lung injury, as has been mentioned). The only EMS study that I am aware of that examined this issue found that there was a pretty significant effect on mortality:

http://emtlife.com/showthread.php?t=20513
http://www.bmj.com/content/341/bmj.c5462.abstract

How carefully did you read that study?

Hyperoxia was defined as PaO2 of 300 mm Hg or greater; hypoxia, PaO2 of less than 60 mm Hg (or ratio of PaO2 to fraction of inspired oxygen <300); and normoxia, not classified as hyperoxia or hypoxia.

Normoxia could be anywhere from 60 to 299 mmHg which could be obtained easily with a NRB mask but more than likely these patients were on a ventilator.

A preplanned secondary analysis also was performed that was identical to the univariable analysis but used a higher PaO2 cutoff to define hyperoxia (400 mm Hg rather than 300 mm Hg).

There were 2410 patients who did not have arterial blood gas values obtained within the first 24 hours in the ICU and were thus excluded from the study. The remaining 6326 patients were from 120 hospitals. The median number of cardiac arrest cases per hospital was 41 (IQR, 17-72). Baseline characteristics for all groups appear in Table 1 and Table 2. Patients were predominantly white and from community, nonacademic hospitals. Sixty-six percent (n = 4146) of patients were living independently prior to hospital admission and 43% (n = 2747) were admitted to the ICU from an emergency department. The most common comorbid condition was severe cardiovascular disease (eg, New York Heart Association class IV; n = 732 patients). Of the 6326 patients, 1156 were in the hyperoxia group (18%), 3999 were in the hypoxia group (63%), and 1171 were in the normoxia group (19%).

Essentially what this study shows is that some hospitals need to refine their ICU management protocols which other hospitals have been doing for 50 years. There may also be other factors such as transport which will require the patient to go back to 100% and then there might be a difficult time walking the patient back down to a lower level. I didn't see much mentioned about post ROSC hypothermia. Little hospitals will also not have Intensivists to manage all the multisystem issues and drips nor with they have accessible dialysis such as CVVH in their ICUs. Mortality might not have been any different if the patient had been weaned to normoxia if these other factors still existed. This is why we have flight, specialty and CCT teams very prevalent in the U.S. in some regions. Or, you have protocols to take the patient to the most appropriate facility and not one that can not effectively correct the underlying condition.

 

[jrm818]

I read my study carefully, but your study and my study are not the same.

Yours is: Association Between Arterial Hyperoxia Following Resuscitation From Cardiac Arrest and In-Hospital Mortality in JAMA

http://jama.ama-assn.org/content/303/21/2165.short

I was talking about: Austin et. al Effect of high flow oxygen on mortality in chronic obstructive pulmonary disease patients in prehospital setting: randomised controlled trial

http://www.bmj.com/content/341/bmj.c5462.abstract

I don't understand how we got from COPD to post ROSC mortality.

 

[Journey]

I read my study carefully, but your study and my study are not the same.

Yours is: Association Between Arterial Hyperoxia Following Resuscitation From Cardiac Arrest and In-Hospital Mortality in JAMA

http://jama.ama-assn.org/content/303/21/2165.short

I don't understand how we got from COPD to post ROSC mortality.

That article came from one of your links.

It is also relavent since the management of oxygenation is now being researched for adults after ROSC. The debate has already been occurring in neonates to where recommendations have been mentioned in NRP but will probably not affect EMS.

I was talking about: Austin et. al Effect of high flow oxygen on mortality in chronic obstructive pulmonary disease patients in prehospital setting: randomised controlled trial

http://www.bmj.com/content/341/bmj.c5462.abstract.

This just confirms what we know about the explanations that have replaced the "hypoxic drive" theory. In the U.S. we have researched this and we now anticipate such a response which is why BiPAP is now used frequently in the ED as an early intervention. Sometimes CPAP will surfice which is found in EMS.

Read up on pulmonary vasoconstriction and V/Q mismatching.

 

[JPINFV]

There are more ways to deliver oxygen than just a 15 L NRB mask. You can given as little as a half a liter in some cases by a nasal cannula or a special mask. EMT training is very limited and probably time does not allow you to be taught all the various methods of oxygen delivery.

I won't argue against that. However when we're discussing treatment by EMS we're limited to the treatment options and assessment tools available. The patient can benefit by a "special mask" all the patient wants, but if the ambulance doesn't carry it, using it isn't an option. I'm also all for continuing pre-established treatments, but I think that altering a treatment plan needs to have more than "the patient is on an ambulance."

If a patient goes into Comfort Care in the hospital, we no longer do pulse ox checks. It will be determined that the O2 and medication relieving pain and the symptoms of dysnpnea will be titrated to patient comfort. In many situations, we will no longer chase the patient with O2 but will rely on the medication to make them comfortable.

As I said earlier, the pulse ox is but one part of an assessment and is better than just blindly applying it to everyone.

Unfortunately some EMTs are required to do pulse ox checks or oxygen is the only medication they have for comfort during transport which is why the patient may also be placed on a NRB mask. Some EMTs do have a difficult time understanding how we can allow a patient with an SpO2 of 70 to be just on a 2 L NC regardless of being in a comfortable state when they are called to transport a patient home or to a hospital facility and will call hospital staff incompetent.

Ok... and "some" hospital staff members and "some" physicians are idiots. You can put "some" in front of any group of people and be right 99% of the time. That doesn't change the fact that a pulse ox has a place in a full assessment of patients and, in conjunction with that assessment, is a part of determining who needs supplemental oxygen started or increased -by- EMS.

There are some medical situations where O2 at 100% is indicated. This is also why we utilize other tools such as SvO2, StO2 and lab values and not just a pulse oximeter. Initially there are very few contraindications to delivering oxygen to a patient. However, you should be educated to understand the body's response to O2 for V/Q mismatch and pulmonary vasoconstriction and respond with the appropriate treatment which in some cases could be more oxgen. For long term consequences, it will depend on the length of time the patient is on the O2 and method of delivery. Yes, an ambulance can do damage by misunderstanding and misusing PEEP or not being prepared for an asthmatic to repond with a drop in SpO2 initially when albuterol is given along with O2 or when CO2 does rise. But, this is more on the training and education of the provider rather than all oxygen is bad.

No one is arguing that all oxygen is bad. People are arguing that misapplied oxygen is bad. Yes, there are conditions that require an FiO2 of 1. However (ignoring the fact that short of CPAP or intubation, an EMS crew won't reach an FiO2 of 1) EMS unfortunately teaches more often than not that the condition requiring that is the presence of an ambulance, which is totally false on it's face.

On an ambulance especially at the EMT-B level you will not have access to all of this data nor will you be able to pharmacologically make someone comfortable who is dyspneic so you may have to go with what you have which is oxygen.

No one is arguing that dyspneic patients shouldn't receive oxygen. People are arguing the eupneic patients with an appropriate saturation doesn't need supplemental oxygen.

 

[Journey]

Ok... and "some" hospital staff members and "some" physicians are idiots. You can put "some" in front of any group of people and be right 99% of the time. That doesn't change the fact that a pulse ox has a place in a full assessment of patients and, in conjunction with that assessment, is a part of determining who needs supplemental oxygen started or increased -by- EMS.

Never said it wasn't but like EMT, it can be just an introductory value with much more to follow through the various diagnostic data that can be done with a few other relatively simple test. Even with just using the pulse ox you should have a greater understanding of how there are disease processes and other factors that affect the number.

No one is arguing that all oxygen is bad. People are arguing that misapplied oxygen is bad. Yes, there are conditions that require an FiO2 of 1. However (ignoring the fact that short of CPAP or intubation, an EMS crew won't reach an FiO2 of 1) EMS unfortunately teaches more often than not that the condition requiring that is the presence of an ambulance, which is totally false on it's face.

Advance to Paramedic and you might able to titrate the oxygen. It seems your argument is that as an EMT-B you can only apply a 15 L mask which is either not quite 1.0 for an FiO2 or that it is too much.

No one is arguing that dyspneic patients shouldn't receive oxygen. People are arguing the eupneic patients with an appropriate saturation doesn't need supplemental oxygen.

Again, a patient does not always have to "look sick" to be sick. Or, the complaint might be something else which is a distractor like sickle cell and pain. Some also get distracted by the diagnosis of "COPD" and forget there are other systems that can fail. You may have to treat more than one system of the body. Unfortunately many EMS protocols are written for one "diagnosis" at a time.

There is really a vast world of disease processes and not every patient will fit neatly into one protocol.

 

[JPINFV]

Advance to Paramedic and you might able to titrate the oxygen. It seems your argument is that as an EMT-B you can only apply a 15 L mask which is either not quite 1.0 for an FiO2 or that it is too much.

No thanks. How about I finish up medical school and advance to physician. Do not pass go. Do not collect $200. How would you take it if I said that maybe you should advance to physician to understand how an assessment and clinical decision making works?

How many services have the ability to run additional testing in the field? Answer: Not many. As such care is provided with an understanding of what tools are available, what interventions are available, and the limitations within. Since EMS doesn't have access to a medical laboratory for such things as ABGs, the only alternative is to throw the kitchen sink at every patient. In which case, why even run the basic POC tests?

Again, a patient does not always have to "look sick" to be sick. Or, the complaint might be something else which is a distractor like sickle cell and pain. Some also get distracted by the diagnosis of "COPD" and forget there are other systems that can fail. You may have to treat more than one system of the body. Unfortunately many EMS protocols are written for one "diagnosis" at a time.

If you're only willing to discuss the application of oxygen in as it relates to the bottom 10% of providers who are going to get irreversibly stuck on a part of medical history, this may not be the board for you. Whether a treatment is appropriate or inappropriate is independent on the ability of any single provider to grasp that concept.

There is really a vast world of disease processes and not every patient will fit neatly into one protocol.

I think you're showing a fundamental lack of understanding of the difference between a "protocol" and an "assessment."

 

[Journey]

If you're only willing to discuss the application of oxygen in as it relates to the bottom 10% of providers who are going to get irreversibly stuck on a part of medical history, this may not be the board for you. Whether a treatment is appropriate or inappropriate is independent on the ability of any single provider to grasp that concept.

Since Paramedics make up less then half or closer to 10% of the providers in many states what are you saying? I initially was speaking more toward an advanced provider but then when you kept referring to a NRB mask, I figured I should take it down a notch to an EMT-B level even though I did continue using terming like Oxyhemoglobin Dissociation Curve, SvO2, A-a gradient and StO2. I do apologize for not explaining those terms more indepth for you.

If you can not identify what your are treating, how do you know if it is appropriate or inappropriate? It seems you are still asking for a blanket protocol and that is or should not be the case. Providers of patient care should be trained and educated to provide more than just recipe medicine.

I think you're showing a fundamental lack of understanding of the difference between a "protocol" and an "assessment."

What are your protocols and how do you do an assessment? Aren't vitals signs part of your assessment to initiate a protocol? Aren't also the one who makes a big deal out of the fact EMTs diagnose? Don't they also do an assessment to do a protocol?

 

[JPINFV]

Something tells me the last two on this list are related.

 

[Akulahawk]

And to get back to what was part of the question originally... yes, it's possible to get too much Oxygen, but you won't see O2 toxicity under normal atmospheric conditions. Even at an FiO 1, the pO2 level in the body is just too low. You'll see other things pop up, but not toxicity.