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In simplest terms the Pa02 is the amount of oxygent that is not bound to HB, but is in the plasma. The Sao2 is the percent of oxygen bound to the heme portion of hemoglobin. Why wouldn't Pao2 and Sa02 vary inversly? It seems to me that if a low Sao2 existed(due to a deficiency of Hb, or inability of oxygen to bind to the Hb), one would find a higer Pa02, as no oxygen molecules are being removed from the plasma? Would Co2 poisoning result in a low sa02, and a higher Pa02 as the heme bonding sites are occupied, thus preventing oxygen from bonding with hemeglobin? Several sources seem to use Sp02 and Sa02 interchangebly. Spo2 and Sa02, while similiar, should represent 2 entirely differnet values, correct? If a patient has an Sp02/Sa02 level within an acceptable range, would that indicate that the Pa02 is also satisfactory? Does the Ca02, simply combine the data gathered by the sa02 and the Pao2, in to a quantifiable amount? If Cao2 is calculated with the following amount, would it stand to reason that a patient could be found to have an adequate Sa02 or Pao2 and still "not be oxygneating properly"? CaO2 = Hb (gm/dl) x 1.34 ml O2/gm Hb x SaO2 + PaO2 x (.003 ml O2/mm Hg/dl). Thank you in advance, and I hope my questions were phrased in a way that made sense to those of you reading(I can't seem to disable the bold font, so that is why this is typed boldly)

Thanks for the response. Sometimes scenarios are hard to decipher. As I stated in my original posting, I would go with the croup/epiglot. route barring a an object in the airway. I guess the best thing would be to attempt back blows and thrusts to see if anything popped out and/or improved the condition. This is what I meant when I said "barring". If this were not to work, then it would be a "pucker" situation. So barring out the foreign object in the airway, I would treat this as croup. My tx. for this would be listed off my SMO's, nebulized EPI, if no improvement, then attempt intubation X 1. We don't have RSI in my SMO's. We used versed and etomidate. Etomidate is for adults only, so we are to used versed for sedation and intubation. You can't really rag on me for it, since I am not the medical director. Sorry. During intubation I'd be on the look out for a foreign object and swelling of the epiglottis. If I could not get the tube, I would cric. I'm not sure why you are disappointed with my treatment plan, or why exactly you take personal offense to my posting. People are strange around here. I see there is a little negative by my posting name, a -1 reputation. I find that quite amusing. Thank you! I still stand by my response to the SPO2. Based on the appearance of this child I would not waste time with it. And I guess when I say waste time, I mean go digging for it, it is deep in our bag. So that situation is unique to us I guess. My priority would be on getting a line and some sort of airway intervention done immediately. Especially with the child who I quote the OP of thread has more cyanosis "than able to shake a stick at". This kid looks like shit and needs agressive, fast treatment. By looking at this kid I know SPO2 is less then ideal. The cyanosis tells me that. I think SPO2 is a great tool, however in this situation I would not worry about it. One thing I do love about SPO2 is trending. So I guess we could use it to see if the neb has helped the kid. However, I think a visual/auditory assessment with be a more reliable/quicker indicator of improvement. By no means did I mean to rile you up. This is a scenario on a forum which I glance at every so often, and I wished to respond. I know the die hards here like to treat this like a firehouse and bust balls etc. I want no part in that. cheers sir. hope you had a merrrrry xmas! Here is a good write up that summarizes my position on Pulse Ox magic! http://tooldtowork.blogspot.com/2008/06/one-where-he-rants-about-pulse-oximetry.html whoa what kind of conclusions are you jumping to? Why are you taking this to a silly level? Let's be real here. I don't NEED the pulse ox in this situation AT ALL. Does cyanosis, stridor and DIB not ENOUGH EVIDENCE to determine whether this kid is in respiratory distress?? Do you need a baseline pulse ox to justify intubating the cyanotic kid with stridor to the doctors in your ER? If you do, it really sucks to work where you are. Pulse ox is NOT going to change my treatment of this patient. Will it change yours? Hell if I never did a serious peds call ever again I'd be very very OK with that. But we know that isn't going to happen. So your thread is well appreciated by me. Thanks.

Ok now AK, Dust to your separate corners. When the bell rings come out fighting. Lets keep it clean. Now in all seriousness as a family man that used to get paid to respond from home it is not the same being around the family when working. Your focus is not on them. You need time where they are your entire focus. Heck you need to go somewhere and shut off the phones and internet and really be just a family at least a few times every year. And as president they can't even do that they still have to stay in touch with the office when on vacation.

Taking pictures of an accident scene is wrong on so many levels. "Hey Roy, can you turn the patient's head a little more to the left while you are holding C-Spine there, I cant get his other eyeball in the shot" ! If you feel the need to keep trophies, you need to get out of the business.

thank you vent and chbare for the information. Chbare-I apologize, that should of read carbon monoxide poisoning not carbon dioxide. If the affinity between carbon monoxide and hemoglobin is roughly 200 times that of oxygen and hemoglobin, i figured that, carbon monoxide poisoning would result in a higher Pao2 and lower Sao2. Which seemed to conradict the refrenced passage. I will go and review the oxyhemoglobin dissociation curve. I think the above statements answers the question i was attempting to ask.

Thats a cute watch. I personally cant handle the feel of a watch on me. But, I figure I will learn to get over that fast..lol Has any PT ever tried to steal it? Do you wear rings / earings when you work?

A watch is a personal choice. It should be functional with being easy to clean and I prefer the band not to conduct heat. It should be easy to see for your work environment and eyesight. It should stand up well to your work environment. I live, work and play around water so being water proof is a plus. I also don't like to switch watches a lot between work and play. The times I do change are for those occasions when only a Rolex will do to go with the shoes.

Take care, chbare. Edit for color problems.

Let's do a little more background work since each of your questions can get rather indepth. The oxygen saturation measured by a pulse oximeter (SpO2) is not the same as the SaO2 measured by a laboratory cooximeter. The pulse oximeter measures the "functional" saturation of hemoglobin. Functional saturation represents the amount of oxygenated hemoglobin in a percentage form of the total reduced and oxygenated hemoglobin. The laboratory cooximeters use multiple wavelengths that distinguish other types of hemoglobin (methemoglobin and carboxyhemoglobin) and thus measure true fractional saturation, or amount of oxygenated hemoglobin in a percentage form of the total reduced + oxygenated hemoglobin + methemoglobin, + carboxyhemoglobin. This is why the SpO2 measurement can exceed the SaO2 reading in certain conditions. Oxygen delivery is a product of cardiac output and oxygen content. The equation for arterial oxygen content is CaO2= (1.37 X Hb X SaO2) + (0.003 X PaO2). From this equation, it is noted that normoxemia does not necessarily guarantee adequate oxygen content. However, since the PaO2 contributes only 0.003 volume percent to the blood oxygen content, the most important factors in determining oxygen content become the hemoglobin concentration and the percent saturation. In order to interpret the results of pulse oximetry, keep in mind the shape of the oxygen hemoglobin dissociation curve, which is not linear and explains why the SpO2 is not a replacement for the SaO2 and the PaO2. Due to the shape of the curve, large decreases in PaO2 may be accompanied by only small changes in the SaO2 in areas other than the steep part of the curve, where a predictable correlation exists between SaO2 and PaO2. A patient’s oxygen content may therefore drop steeply before it is detected by pulse oximetry. Shifts in the oxyhemoglobin saturation curve also influence the relationship between PaO2 and SpO2. The information provided by the pulse oximeter is not a replacement for the PaO2, but is complementary to the PaO2. However, the pulse oximeter becomes an ideal continuous monitor of tissue oxygen delivery in the face of normal hemoglobin concentration, and normal types of hemoglobin (vs. methemoglobin and carboxyhemoglobin). http://www.lakesidepress.com/pulmonary/ABG/PO2.htm Excellent for oxygen hemoglobin dissociation curve http://www.ccmtutorials.com/rs/oxygen/index.htm As much as I hate to do this, I am going to reference a thread from the other forum since it also addresses some of the same questions. http://www.emtlife.com/showthread.php?t=7157&highlight=PaO2 Now of course before one gets deeply into the physiology one should have an understanding of their oxygen equipment and the differences between oxygenation and ventilation. You may already have mastered that but many have not which is why I'm back tracking a little.

And no passeport either. Meanwhile, they still give the full anal probe to the guy in the wheelchair with military ID and a round trip ticket.

Here in Australia EMS and Fire are two totally different government funded services. Each state in Australia has a Metropolitan and Country branch of Fire Service and each state has there own Ambulance Service. In my state Melbourne has the Metropolitan Fire Brigade which is all paid, full time firefighters. In the country interface we have Country Fire Authority which encumbers just over 1000 fire stations, they have about 3,000 paid full time fire fighters and 30,000 volunteers. The larger rural city's and large coastal towns have paid full time staff and the remaining stations have volunteers. It's no walk in the park to become a paid firefighter, the entry test is quiet extensive and so is the 4 months of academy. The Ambulance Service is all paid full time staff, we don't have volunteers in EMS apart from CERT in remote areas. Again it's quiet a vigorous entry requirement to become a paramedic, most have 3 years degrees and undertake graduate training. We don't seem to experience the conflict and problems between EMS and Fire as you guys do over in America.

We don't "need" That's your argument?? Why not use all the tools at hand when assessing resp status? I know damn well any ER doc will ask the $100 question when you present your intubated kid to him. "What was his SpO2 on room air?" Don't you gather a "Baseline" to compare to after treatment? Hmmm.... I guess we don't need a cuff to assess BP either.... Cap refil will suffice. We don't need a thermometer to assess Temp either, skin to skin contact will do. Heck... Why even use EtCO2 after he is intubated, you have a stethoscope! IMO, using all the tools available is part of a complete assessment. Maybe it takes you longer to snap on an SpO2 than it does me though.

All this animosity stems from "HOSE envy". Sadly its true some people feel woefully under equipped to handle all situations so they choose to canonize the one the have mastered. Its a shame really all they need is a little confidence building and they to will feel adequate in most situations. But one truth still remains some of use can be firemen and emt's some can't. P.S. I love stirring the pot Merry Christmas to all