The normal perfusion index (PI) ranges from 0.02% to 20% showing weak to strong pulse strength. How accurate is it? You can never say that your oximeter is 100% accurate. It can show a 2% over or 2% under due to your arterial blood gas or mechanical fault.

What is normal pi?

PI's values range from 0.02% (weak pulse) to 20% (strong pulse). A site with a high PI number generally indicates an optimal monitoring site. PI is a relative number and varies depending on patients, physiological conditions, and monitoring sites. Therefore, each patient's “normal” PI is unique.

What is a good pi ratio?

The Polarization Index is derived by the ratio between the one minute reading and the ten minute reading. Recommended minimum PI results for suitability for service (or implementation of high voltage testing) is widely accepted as 2:1 or greater. Any reading lower than this minimum value is a concern.