Now, it has become the “sixth” vital sign, along with pulse rate, blood pressure, respirations, mental status, and blood glucose.
We used to actually assess the patient’s work of breathing, skin color, temp, and moisture, along with capillary refill time. Does anyone else remember “CRT is less than 2?” You know, squeezing the patient’s fingernail, or touching their forehead, and counting how long it took for color to return?
CRT, skin, and work of breathing can tell you a whole lot more about a patient’s status than a pulse-ox ever could. And don’t even get me started on using the pulse-ox to count a pulse.
I rarely use pulse oximetry to guide my application of oxygen. If I have a patient with a known history of emphysema, breathing 20 times a minute, with no distress, with clear breath sounds, and no accessory muscle usage, chances are that patient does not need a non-rebreather simply because “their O2 sat is 90.”
I am much more concerned with the end-tidal CO2 on the emphysema patient than I am with the pulse oximetry.
Using pulse oximetry can be valuable, but all too often, it is used in place of a good assessment, and that’s just plain lazy.