When to believe the pulse oxymeter, when not?

[DFIB]

I can diagnose breast masses by touch. Never fail. I have not misdiagnosed one that I can think of in 2011, so I am batting closer to 100%, but will only claim 99% for now.

Edited December 20, 2011 by DFIB

[tniuqs]

I can tell you the patients ICP just by touching his head!

Sweet !

EDIT: I`m working on EF by laying my hand on the thorax - but I still have a 20% failure rate there...

Bummer !

[Just Plain Ruff]

Here is my diagnosis percentage

1. Stupid - 100%

2. Member of the people of walmart sect - 100%

3. Redneck - 75% as some rednecks in reality do NOT actually have red necks.

4. Sniffles - 100%

5. Sneezes - 100%

6. Head anus conversion - 80%

7. MI's - 101% without the monitor, only 57% with the monitor

8. Mad Cow disease - 100% with the cow, 0% without seeing the cow

9. Decapitations - 100%

10. Complications from a Vasectomy - 100%

11. ICP number - 43%

12. Blood pressure (within 2 measures of standard deviation using the Sheldon Cooper method)- 98% with cuff, 75% without cuff using radial pulse, 60% using femoral pulse and 10% using pedal pulse

13. Cancer - 5% unless it's skin cancer and then I have a 85% correct diagnosis rate

And finally, my greatest diagnosis success to date

That Flaming is Nucking Futts and talking out his derriere (see number 6 above) - 97%

[Vorenus]

9. Decapitations - 100%

Cool, bro!

I suck with those - they are so easy to overlook...

[Just Plain Ruff]

Cool, bro!

I suck with those - they are so easy to overlook...

Yeah I actually have to rate myself downwards on the decaps, I did compressions and then walked over and ventillated. Took me a minute to realize oops, There goes my perfect score.

[Bernhard]

(P.S.: I will check all our four oxymeters on one test person soon, just getting curious)

OK, as promised, I did the test, three pulse oxymeters ("PO") were available.

PO#1: handheld device with external sensor

PO#2: fingerclip device

PO#3: LP12 with external sensor

All of them used in the initial scenarios of the original post. The fourth one I still had no access to, will follow someday.

My findings, all tested on my own hand on different fingers at the same time, changed several times: PO#1 and PO#2 gave similar readings, PO#3 was totally panicking. Where PO#1 and PO#2 both had a reading of ~95%, PO#3 gave several ascending and descending measurements between 98% and 58%. Remember: it was on MY finger!

So I checked PO#3 closely and found a defective cable. OK, that explains a lot, even the long time to wait for a signal. Remarkable: signal was good on waveform and pulse. I got suspicious when the thing still showed a perfect signal and measurements even when taken away from the finger. However, it passed all the regular standard tests at shift change as well as the yearly measurement in the service lab!

The other two pulse oxymeters always were in sync, only that their measurements differed around 0-4%, depending on their actual fitting position on the finger (millimeters seem to count) and some random influences.

What did I learn:

• Know your tools, don't overrate them and examine them closely when something seems wrong. Check waveform and signal/pulse relation on pulse oxymeters as additional hints.
  
• Varying pulse oxymeter readings are possible with very minimal position changes.
  
• A variation in accuracy of 0-4% (at least roughly based on my little test) is to be expected. I will check the manuals for this ASAP.
  
• EMTcity is a great place to discuss basic things.
  

Thank you for the great discussion!

[BAYAMedic]

You guys forgot the most important tool we have on our bus. The Lifepack 15 with the 12 lead crainial cord attached to see if they have brain activity....

Fireman1037

[Bernhard]

You guys forgot the most important tool we have on our bus. The Lifepack 15 with the 12 lead crainial cord attached to see if they have brain activity....

I'll try it just after getting a measurement attaching the oxygene meter to the patient's nose.

[bTW: I'm impressed - we don't have LP15 or anything like this on public transport vehicles over here]