Pulse Oximeters

[citizensoldier16]

I have a Nonin fingertip model that's held up well. Working in EMS though (paramedic) I rely less on Sp02 and will almost always reach for the capnometry/capnography in assessment and diagnosis of respiratory patients. In fact, the pulse ox is just about the last diagnosis tool I attach to any patient Just my $0.02.

[joker581]

I've only recently graduated paramedic school and just have about two years of EMS experience, but a couple of questions came to mind when reading the discussion of the hypoxic drive and the potential for knocking it out.

If you were to give too much O2 and cause the patient to stop breathing due to them no longer being hypoxic, would they start breathing again once they again became hypoxic if you weren't bagging them?

If it is possible to stop someone's breathing due to O2 overdose, wouldn't they likely be better off in the short term if you were to bag them with a high concentration of O2? Being in a state of constant hypoxia isn't exactly healthy after all.

[citizensoldier16]

There are numerous and inconsistent opinions on hypoxic drive. As an EMS provider, you should never withhold oxygen from ANY patient experiencing respiratory compromise. From all the literature I've read (NEJM, JEMS, Paramedicine Today, Mosby, Brady, etc) the effects of high-flow oxygen on the hypoxic drive takes days to months to manifest in patients, and symptoms take even longer to show up. You may have heard that you shouldn't give a COPD patient oxygen, but I'll tell you what my paramedic instructor once told me:

"Nobody has ever died from too much oxygen, but plenty of people HAVE died from a lack of it."

If your patient is in respiratory distress, the first intervention should always be high flow oxygen. Nine times out of ten, that'll fix their problem. If not, then something (fluid) is preventing gas exchange in the lungs and then we can then start looking at options like Lasix, CPAP/BiPAP, or even Nitro.

EDIT: Just remember that a patient exposed to carbon monoxide will have a very high SpO2 reading because hemoglobin would rather bind with CO than with O2. Keep that in mind, and don't rely fully on your pulse-ox. As I said before, I would rather reach for the capnometry first.

[CCFP]

Also, for the point of knocking out a COPDers Hypoxic Drive, Ventilate them and titrate the O2 back down to a level that pleases their barroreceptors!

I believe you meant chemoreceptors, and there are newer pulse oximeters available which measure carboxyhemoglobin, and methemoglobin as well. I believe these would be far more useful (in the field) than simply measuring O2 saturation. We monitor Spo2 routinely, but place much greater emphasis on ETCO2 as a measure of adequate/inadequate ventilation. I think there'll always be a place for pulse oximetry, unless you choose not to utilize it and instead use an ISTAT, or similar device for gases. That's expensive though on an ongoing basis. Just my 0.02.

[dsa]

There are numerous and inconsistent opinions on hypoxic drive. As an EMS provider, you should never withhold oxygen from ANY patient experiencing respiratory compromise. From all the literature I've read (NEJM, JEMS, Paramedicine Today, Mosby, Brady, etc) the effects of high-flow oxygen on the hypoxic drive takes days to months to manifest in patients, and symptoms take even longer to show up. You may have heard that you shouldn't give a COPD patient oxygen, but I'll tell you what my paramedic instructor once told me:

"Nobody has ever died from too much oxygen, but plenty of people HAVE died from a lack of it."

If your patient is in respiratory distress, the first intervention should always be high flow oxygen. Nine times out of ten, that'll fix their problem. If not, then something (fluid) is preventing gas exchange in the lungs and then we can then start looking at options like Lasix, CPAP/BiPAP, or even Nitro.

EDIT: Just remember that a patient exposed to carbon monoxide will have a very high SpO2 reading because hemoglobin would rather bind with CO than with O2. Keep that in mind, and don't rely fully on your pulse-ox. As I said before, I would rather reach for the capnometry first.

Except in cases of severe Paraquat poisoning; O2 should not be administered unless signs of severe respiratory distress are present. It causes severe lesions in the lungs when given to victims of Paraquat poisoning. Everything else in this post is dead on accurate.

I have been a NREMT-P for 18 years and have been teaching Paramedic courses for the last 5 years; my students have a better that 90% first time pass rate on the national registry exam.