tcripp Posted January 23, 2012 Posted January 23, 2012 Sat in what I felt was a very good airway class on Saturday and came away with several learnings, one of which is the title of this post. Makes a lot of sense to me, but I do have a question that I didn't think to ask until, well, right now. I've noticed that many of my frail little old ladies will show a higher ETCO2 reading for which I will now start using my warm saline and providing blankets and a warm box. But, does anyone know if this shift in reading is proportionate to the amount of hypo/hyperthermia? By that I mean, will mild hypo/hyper show a change or is this more in moderate/severe? Toni
Kiwiology Posted January 23, 2012 Posted January 23, 2012 warm box. Snicker But, does anyone know if this shift in reading is proportionate to the amount of hypo/hyperthermia? By that I mean, will mild hypo/hyper show a change or is this more in moderate/severe? The solubility of a gas in a solvent (like carbon dioxide in blood whodathunkit?) is proportionate to temperature; so lower temperature = less soluble so there's your lower ETCO2 .. hmm I feel like I just stated the obvious right there? Other than that I have no idea and am going to leave now before that bloody emergentology doctorate fella comes in here complaining about how my pointing out basic science molested him once again sheez ...
tcripp Posted January 23, 2012 Author Posted January 23, 2012 Snicker Oh, hell, Kiwi. Apparently, I forgot about the group of people on this forum. The solubility of a gas in a solvent (like carbon dioxide in blood whodathunkit?) is proportionate to temperature; so lower temperature = less soluble so there's your lower ETCO2 .. hmm I feel like I just stated the obvious right there? Um, yeah. I do recall that in class. But the question was more to the readability on the monitor.
mobey Posted January 24, 2012 Posted January 24, 2012 OK, I'll stab. Yes. Temperature has a direct relationship with the bohr effect. Although not a major influence, a hypothermic patient will have a shift to the left, and a hyperthermic pt - a shift to the right. From what I have read, it does not have to be severe hypo/hyper, but overall temperature is one of the "lesser" important factors when dealing with oxyhemoglobin curve. That said... Hypothermia has many more reprocussions I am sure you are aware of. Warming the elderly is always a top priority for me too. In my opinion, one that is too often overlooked, especially in people who cannot shiver. http://www.ventworld.com/resources/oxydisso/dissoc.html#factors http://jap.physiology.org/content/57/2/429.abstract http://www.sciencedirect.com/science/article/pii/0167483882902096
DwayneEMTP Posted January 24, 2012 Posted January 24, 2012 Holy shit Toni! I just occured to me, and this has been nagging at me since you changed your avatar, that with your pale hair, if your nose was pointier, you'd look just like the good witch on the Wizard of Oz!! I kind of had a WILF thing for her when I was a kid.... That's it...that's all I really have to add on the solubility of gas into a solvent with variable temperatures and warm boxes... Dwayne
tcripp Posted January 24, 2012 Author Posted January 24, 2012 Glenda the good witch? Well, Dwayne, I will have to say that one is a first! I guess I'll have to post the pic of me when I was 21 and then you can tell me who I look(ed) like! Mobey - thanks for the links. I am aware about the little old people and hypothermia and do try to use warming mechanisms (including warm saline), but now I just feel like I have another tool to remind me or to let me know if my efforts are beneficial. You know they will NEVER tell you they are cold as they don't want to be a bother.
zmedic Posted January 27, 2012 Posted January 27, 2012 I think the reason that they have higher C02 levels is more likely due to the fact that they will have a lower respiratory rate and/or smaller tidal volumes when hypothermic rather than changes on the blood itself. If patients are producing C02 at a similar level but are not breathing it off as well, their end tidal C02 will be higher. Furthermore, one would expect that the body would have a higher metabolic rate when hypothermic in an attempt to generate heat (like shivering), which would also be expected to increase C02. Truth be told, I don't think I would spend too much time worrying about the C02. I would spend more time looking at things like shivering, mental status, heart and respiratory rate to determine severity of hypothermia.
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