Quote from SteveRN21
I'm wondering if the pTC02 actually means transcutaneous CO2 measurement. <SNIP>
Plus, we don't typically measure pulse oximetry on the thorax or thigh. <SNIP>
You're correct, Steve...in fact, you'll never
measure "pulse oximetry" on the chest or thigh. However, unlike transcutaneous monitors, pulse oximeters measure the amount of oxygen "saturated" hemoglobin (using UV light and "Beer's" law of absorption) and the calculation is reported as a percentage ( % ). Transcutaneous monitors use the same polarographic electrodes found in blood gas analyzers (Clark electrode for O2, Severinghaus electrode for CO2) and provide a direct measurement of the oxygen that diffuses to the skin surface from the dermal capillary bed beneath. PtcO2 stands for "transcutaneous oxygen tension" (partial pressure
of oxygen reported in mmHg or "torr")...the lower case "tc" being the "transcutaneous" portion (duh, I know). If the monitor in the question were measuring carbon dioxide (which it can), it would have read "PtcCO2".
Blah, blah, blah...sorry. I was just trying to clear up any confusion about the measurement being reported in torr.
P.S. I went ahead and sat for the exam WITHOUT ever knowing the answer to my question. Low and behold, there wasn't even a referrence to TGA in any of the 140 questions!! I'm still curious to know why TGA was the answer (other than the fact that none of the other answers made sense)...but either way, I'm now "RRT-NPS, NREMT-P"...and $500 richer for adding another set of initials (that no one really gives a rats-ass about) to my uniform!!
Next up...C-NPT exam.