Upper extremity arteriovenous fistula does not affect pulse oximetry readings

Area of Science:

• Vascular Surgery
• Nephrology
• Physiology

Background:

• Arteriovenous fistulas (AVFs) are surgically created in the upper extremity to facilitate hemodialysis.
• Altered blood flow distal to an AVF may theoretically impact physiological measurements.
• Understanding these physiological changes is crucial for patient monitoring and AVF management.

Purpose of the Study:

• To prospectively measure changes in pulse oximetry (SpO2), systemic blood pressure, and skin temperature in the upper extremity of patients with an AVF.
• To compare measurements in the AVF-bearing arm against the contralateral non-AVF arm.
• To identify factors influencing blood flow alterations distal to an AVF.

Main Methods:

• A prospective case-control study design was employed.
• The non-AVF upper extremity served as the control for each patient.
• Evaluated influencing factors included gender, AVF aneurysm, peripheral vascular disease, diabetes mellitus, and vasodilator therapy.

Main Results:

• Thirty patients were enrolled in the study.
• Significant alterations in skin temperature and blood pressure were observed in the hand distal to the AVF.
• No significant changes in SpO2 readings were detected.

Conclusions:

• Upper extremity AVFs significantly alter blood pressure and skin temperature compared to the non-fistula side.
• SpO2 measurements are not significantly affected by the presence of an AVF, assuming adequate signal quality.
• These findings are important for accurate physiological monitoring in patients with AVFs.