increased activity, decreased HR??

[querynurse]

Just curious if this could be the result of a faulty pulse oximeter or if there is some way to explain this physiologicaly. A geriatric patient in with a dx of pneumonia was being mobilized by PT. when resting and on 2L 02 they had a baseline pulse of around 100-120 bpm. When PT attempted to get them up they desated to around the 70% but HR also dropped to around 65-70 bpm, shouldn't the HR increase???

[Biffbradford]

Check the probe. If it's reading correct, then they just missed out on a code situation. If the heart is not getting oxygen, then it shuts down!

[Neuro Guy NP, DNP, PhD, APRN]

I agree that it may well have been a faulty machine, etc. b/c normally the HR is lower at rest than at work. As for the decrease in O2 sat to 70%, it may have been manifestation of dyspnea on exertion, assuming the pulse ox device was correct, as PT often does make patient engage in what heavy exercise/ambulation (heavy in the patient's perspective, especially post-op or elderly).

Hope that helps.

[Skip219, BSN, RN]

Geriatric patients have decreased ability to compensate for increased perfusion situations: increased physical activity. Likewise, I have seen patients get bradycardic with severe drops in O2 sats: its a physiological response you will learn about in advance physiology.

Hope this helps,

Skip

[porterwoman]

I'm going to quote from a critical care book I keep around for reference. This is in reference to the effect of cardiac output on tissue oxygenation:

"To maintain normal aerobic metabolism, the tissues must extract increasing amounts of O2 from the blood. When this increase in extraction can no longer compensate for the decreased CO, anaerobic metabolism occurs. This results in a buildup of lactic acid, which further deperesses the myocardium and results in an even lower CO."

So, it sounds like your patient had already compensated for the low O2 sat as much as possible and was becoming acidotic and decompensating fast. Add on to that the geriatric piece, which would mean your patient would not have the same compensatory mechanisms as a younger person, and would respond more slowly to O2 therapy, and you've got a serious situation. Definitely time to tell the PT to stop, get the patient sitting down, and back to bed. What was the sat before PT?

[ObtundedRN, BSN, RN]

Was the patient straining? Vaso-vagal?