Reliability of pulse oximetry

Started by Russell Coupland, January 06, 2005, 02:54:26 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Russell Coupland

Today, we would never be without our SPO2 monitor. We are taught they sometimes read false low due to artefacts, but never read false high.

We had a case a few days ago where the pulse oximeter was reading a steady 99% with a heart rate of 76beats/min. We then noticed that the EKG was obviously faster than 76 - probably in the low 100's. We checked the monitor - the heart rate was set to read from the oximeter (- I often do this as a default as I often do not apply EKG to young healthy patients). We then checked the finger probe - it was STILL CLIPPED TO THE STAINLESS STEEL ANESTHETIC MACHINE TROLLEY! yet it gave a perfect waveform, a rate of 76 and a saturation of 99%.

We placed the probe on the patient and instantly the saturation reading changed to the actual value of about 96% and the heart rate showed about 100/min.

How could a non-applied probe give such a falsely reassuring reading? I have my suspicions that it was an incompatibility of the probe (Nelcor) with the monitor (Datex-Ohmeda). Any other ideas?