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You are correct; however, we must keep this in perspective. I will will use the content of arterial oxygen formula to illustrate the point: The CaO2 is calculated with the following: CaO2 = (1.34 * Hemoglobin * SaO2) + (PaO2 * 0.003) Let's say you have a Hb of 13, SaO2 of 96% and a PaO2 of 100 mm/Hg CaO2 = (1,34 * 13 * 0.96) + (100 * 0.003) 16.7 + 0.3 = ~17 ml/O2/100 ml blood So, you can see, even with a PaO2 of 100 mm/Hg, you are only adding 0.3 ml/O2/100 ml blood to your total CaO2 Let's say in the land of Oz we are able to have a 100% oxygen atmosphere and by an act of God we are able to increase the PaO2 to 760 mm/Hg This would only come to 2.28. This is why to have meaningful increases in oxygen via dissolved oxygen content, we typically look to hyperbaric therapy to significantly increase the partial pressure and thus dissolved pressure of oxygen in the body. Of course, such concentrations are rather toxic. Take care, chbare.

Not true, by increasing the partial pressure of oxygen (PO2), once the Hgb are fully saturated (oxyhemglobin) the oxygen will further saturate the blood plasma, leading to an overall higher Oxygen content in the blood. O2 will dissolve in blood plasma.

There's a fair amount of back-and-forth recently about the status of supplementary oxygen for a few high-profile conditions, such as stroke and cardiac arrest. It'll be nice to see how that eventually cashes out, but my personal interest is in the less-discussed fronts. A lot of prehospital providers -- particularly the poor BLS buggers who can't do much else -- tend to use O2 as a panacea, on the somewhat religious assumption that it'll help with almost any ailment. 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? I'm interested in this to better inform us all about the true indications for supplementary oxygen. It probably goes without saying that someone with dyspnea and trouble oxygenating will improve with high-concentration O2, but it is far from obvious whether the guy with the broken leg will hurt any less, the guy with appendicitis will live any longer, or the woman with nausea/vomiting will feel any better. "Throw on a cannula" may not be all that harmful but we'd probably all rather avoid unnecessary treatment when possible. So -- any thoughts? I'm interested in everything from AAA to Zebras. I will say for my own small contribution that I've had mixed results giving patients with anxiety and similar psych states low-flow O2 by cannula; sometimes seems to help, sometimes not at all.

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.

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

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.

True, but it's like saying that a garden hose is going to help stop a forest fire. Sure, you're getting water on the fire, but the quantity just isn't there to be significant. Additionally, someone who is hypoxic due to low anemia is still going to show signs of hypoxia minus a low pulse ox reading. This is because a pulse ox measures the percent of red blood cells that are saturated, and not the oxygen carrying capacity of the blood.

Pain induced hypoxia is a good one. That being hypoxia that stems from a decreased minute volume due to pain on inspiration. Namely broken ribs, but I'm sure there's a plethora of conditions that would cause this trouble. Especially for the BLS guys who might not necessarily have any pharmacological analgesia. Seeing as you are looking for experience: When I had my appendix out I had a left over bubble of laprosocopy gas left over which was quite painful for a few days, particularly on inspiration. after a few moments I would start to feel increasingly short of breath which would make me breath harder which hurt, etc. It would come and go in "attacks". Whenever I'd have an "attack", they would whack a pulse ox on, and a nasal cannula and 5 mins later, no troubles. I like the idea of this thread. As time goes on I think we are going to see more precautions and relative contraindications for certain Fi02s. We sit an learn at uni how archaic the "Everyone gets 8 through a hudson" idea is, then we sit down in prac classes and that's exactly what we get taught to do. It grinds my gears.

Squint you can have him back! I don’t want him. You’re absolutely right. I just think it’s going to be impossible to motivate the Feds until such time as this violation is validated in court. I don’t think we should just up and walk out en mass. I think we need to speak up on each other’s behalf with one clear collective voice. Motion seconded! Ed

Ah an old friend ... sweet, he knows me by my first name with the Long Gun Registry . I KNOW the Feds have jurisdiction over Bill 21 it does violate the Canadian Charter of Rights and Freedoms As IF EMS would ever walk OUT en mass we aint the ferry workers or the postal workers Gorden Campbell do yourself a favour and please remove: HEAD FROM RECTUM.

Not bad $$, but the acdemy guys in the OCFA I think make 90k a year without OT.

Southland was/is a decent show and I didn't know it was back on or had been cancelled/transferred.

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.