Interfinger Differences in Pulse Oximetry Signal-Derived Peripheral Perfusion Index: A Single-Center Exploratory...

Area of Science:

• Critical Care Medicine
• Physiology
• Medical Devices

Background:

• Peripheral perfusion monitoring is essential for critically ill patients, as poor perfusion indicates a worse prognosis.
• Peripheral perfusion index (PPI), measured by pulse oximetry, quantifies perfusion but varies between fingers.
• Probe site changes are recommended to prevent burns, but interfinger PPI variations reduce reliability.

Purpose of the Study:

• To assess interfinger differences in peripheral perfusion index (PPI) measurements.
• To identify finger pairs with minimal PPI fluctuation for consistent monitoring.
• To enhance the reliability of pulse oximetry in clinical and research settings.

Main Methods:

• A prospective study measured pulse amplitude index (PAI) on all five fingers of 30 healthy volunteers.
• Measurements were taken across three room temperatures (16°C, 22°C, 28°C) to capture diverse PAI values.
• Paired t-tests with Bonferroni correction analyzed 10 finger pairs, with p < 0.005 considered significant.

Main Results:

• The index-ring finger combination exhibited the least PAI difference (0.07% ± 1.89%, p = 0.74).
• Middle-ring (0.45% ± 1.93%, p = 0.03) and index-middle (0.52% ± 2.05%, p = 0.02) finger pairs also showed minimal differences.
• All other finger combinations displayed statistically significant interfinger differences (p < 0.001).

Conclusions:

• The smallest interfinger difference in PPI values was observed between the index and ring fingers.
• Alternating probe placement between the index and ring fingers may allow for consistent PPI measurements.
• This finding can improve the reliability of peripheral perfusion monitoring in clinical practice and research.