analysis of patterns of pulse oximeter perfusion index according to postural change during gynecological surgery

Background :monitoring devices are being developed to simultaneously improve oxygen saturation (spo2) accuracy and monitor various parameters. the peripheral perfusion index (pi) is useful for observing perfusion trends because it is calculated based on peripheral blood flow.objectives :this study aimed to analyze the peripheral pi patterns according to postural changes during gynecological surgery. methods :sixty-six patients who underwent gynecological surgery under general anesthesia between 2024 and 2025 were enrolled. the primary outcome was to observe and analyze changes in the pi with the four stages of postural change. changes in hemodynamic variables may accompany this, and an additional analysis was conducted to determine whether there was a correlation. as a secondary outcome, we compared and analyzed the effects of respiratory dynamics on oxygen content (spoc) according to the four stages of postural changes. results :comparison and analysis of the changes to the initial values revealed no significant differences in the spoc values. however, pleth variability index (pvi) and pi showed significant differences, whereas pvi did not differ significantly from the initial value in the trendelenburg position (p = 0.202). the pi showed significant differences for all posture changes (p < 0.001).conclusions :continuous changes and peripheral perfusion maintenance can be effectively monitored according to patient posture when monitoring patients using pi. this can facilitate appropriate anesthetic management for patients.