Figure 1 Distribution of oxygen reserve index (ORi) values across subsequent measurement points. The figure shows box-and-whisker plots of ORi values at defined measurement points: BEG – before induction of anesthesia, PREOX – after pre-oxygenation with 100% oxygen, INDUCT – after induction of anesthesia, PP+T – after placing the patient in the Trendelenburg position and establishing pneumoperitoneum, AFT10 – 10 minutes after PP+T, AFT30 – after 30 minutes, AFT50 – after 50 minutes, AFT70 – after 70 minutes, ZERO – after returning the patient to the initial position, EXTUB – after extubation, PACU – before transferring the patient to the post-anesthesia care unit. Significant differences in ORi values were found between measurement points, with the lowest median recorded at the BEG point compared to the other measurement points (P<0.0001). The differences between the measurement points were assessed using Friedman ANOVA (with post hoc analysis) for multiple comparisons.