What Is Perfusion Index?

A pulse oximeter provides the data for perfusion index calculations.

The "perfusion index" or "PI" reflects the amount of blood flow being measured by an instrument called a "pulse oximeter." A health care professional tests blood flow to establish norms and aid in identifying changes in a patient's condition.

Benefits

As a noninvasive assessment tool, the perfusion index provides information without subjecting the patient to potentially dangerous tests. The pulse oximeter clips on to a patient's finger, toe, ear or nose and gives objective numeric data on the blood flow to the site.

Function

Past and proposed clinical trials look at the applications of PI for evaluating patient conditions and changes in many scenarios. In the surgical suite, changes in the PI have been tied to the moment when anesthesia takes effect. For an infant, child or unresponsive patient, changes can alert caregivers to deterioration of the patient's condition by identifying decreased oxygenation at the reporting site.

Considerations

The perfusion index varies from patient to patient and and from one reading location to another. Rather than a generic "normal" PI, the number reflects what is normal for that particular patient.

References

• Datex-Ohmeda: Make the Right Connection Guide
• Masimo Corporation: Perfusion Index Whitepaper
• Masimo Corporation: Clinical Applications of Perfusion Index
• Seoul National University Hospital: Comparison of Perfusion Index, T Wave Amplitude, Systolic Blood Pressure and Heart Rate

Resources

• Ridling and Kroon: Comparing Three Methods of Assessing Peripheral Perfusion