Epidural anesthesia affects pulse oximeter readings and response time.

Area of Science:

• Anesthesiology
• Physiology
• Medical Devices

Background:

• Epidural anesthesia significantly alters microcirculation.
• Pulse oximetry (SpO2) relies on adequate blood flow for accurate readings.
• Understanding anesthesia's impact on SpO2 and response time is crucial for patient monitoring.

Purpose of the Study:

• To investigate the effects of lumbar and cervical epidural anesthesia on pulse oximeter readings (SpO2) and response time.
• To correlate changes in SpO2 and response time with skin blood flow (SBF).

Main Methods:

• Twenty patients were divided into lumbar epidural (L-EPI) and cervical epidural (C-EPI) groups.
• SpO2 and skin blood flow (SBF) were measured simultaneously at the finger and toe.
• Response time was calculated using the breath-holding method before and after anesthesia.

Main Results:

• Epidural anesthesia altered SBF, increasing it in blocked areas and decreasing it in non-blocked areas.
• SpO2 changes varied: increased at the finger and decreased at the toe in L-EPI; decreased at both in C-EPI.
• Response time differences correlated significantly with SBF changes, indicating altered microcirculatory responses.

Conclusions:

• Epidural anesthesia can lower SpO2 and shorten response times via vasodilation in blocked areas.
• Compensatory vasoconstriction in non-blocked areas leads to opposite effects.
• Anesthesia location influences microcirculatory and SpO2 responses, impacting monitoring accuracy.