semiatic
PRbpm

PR or bpm on a pulse oximeter (pulse rate)

PR is pulse rate: how many pulses per minute the oximeter counts at the fingertip, from the same light signal it uses for oxygen. For most people it matches the heart rate, but it counts pulses that reach the finger, so an irregular heartbeat can make it wrong.

Check your oximeter’s manual — makers differ.

What it is for

Read it together with the signal indicator, as for SpO2. Beurer (PO 45) warns that “for people with cardiac arrhythmia, the oxygen saturation level (SpO) readings and the heart rate (PRbpm) may be incorrect or the measurement may not be possible at all”, and its PO 60 troubleshooting table lists cardiac arrhythmia as a cause of erratic readings with the answer “Seek medical attention”. The Microlife OXY 200 beeps as a “risk reminder” when the pulse is lower than 50 bpm or higher than 130 bpm, according to Microlife’s manual; the other manuals read describe no such sound.

These pages report what each maker’s manual says and quote it wherever health is involved. They do not diagnose anything, they are not medical advice, and they do not tell you whether an oxygen or pulse reading is right for you or what to do about it; only your own oximeter’s manual and your doctor or nurse can do that for the person you are looking after.

What it looks like
The second main number, marked PR, PRbpm or bpm, usually below or beside SpO2.
Names makers use
PR bpm (Beurer PO 30, PO 45 and PO 60, Microlife OXY 300); PR (Masimo MightySat Rx); Pulse rate, beats per minute (Nonin Onyx Vantage 9590)

Where makes differ

The range each model can show differs. Nonin gives 18 to 321 beats per minute for the 9590, Masimo 25 to 240 bpm for the MightySat, Beurer 30 to 250 beats per minute for the PO 45 and PO 60, and Microlife 30 to 250 bpm for the OXY 300. Accuracy is quoted as Arms too: Masimo gives 3 bpm at rest and 5 bpm in motion, Nonin ±3 digits, Beurer (PO 60) ±2 bpm.

What it does not mean

It is not blood pressure and it is not a measure of how strong the pulse is. A steady PR does not show that the heart rhythm is regular: Beurer’s manuals say an arrhythmia can make both readings wrong.

Other symbols with the same shapes

Sources

No published standard we could check defines what a fingertip pulse oximeter’s display shows, so this meaning is taken from 4 makers’ own manuals and support pages, each fetched and read on the date shown:

Written in our own words; quotations are the makers’ wording.