Effects of Different Hemoglobin Levels on Near-Infrared Spectroscopy-Derived Cerebral Oxygen Saturation in Elderly Patients Undergoing Noncardiac Surgery

Fig. 1. Correlation between Hb concentration and NIRS-derived rSO2 measured after anesthesia induction, pre-transfusion, and posttransfusion. Data were analyzed using Spearman r test (n = 129, r = 0.3479, p < 0.0001).

Fig. 2. Pre- and post-transfusion Hb concentrations in patients; RBC transfusion starting at Hb <7.5 g/dL, n = 21; 7.5–8.5 g/dL, n = 21; or >8 g/dL, n = 25. Data were analyzed using two-way ANOVA with Bonferroni post hoc analyses and expressed as mean ± SD. Lines indicate significant post-transfusion differences between groups (p < 0.01).

Fig. 3. rSO2 values at baseline, pre-, and post-transfusion in patients; RBC transfusion starting at pre-transfusion Hb <7.5 g/dL, 7.5–8.5 g/dL, or >8.5 g/dL. Data were analyzed using two-way ANOVA with Bonferroni post hoc analyses and expressed as mean ± SD (<7.5 g/dL, n = 21; 7.5–8.5 g/dL, n = 21; >8.5 g/dL, n = 25; p < 0.01; *compared to >8.5 g/dL pre-transfusion; lines indicate significant post-transfusion differences between groups).

Fig. 4. rSO2 changes from baseline to pre-transfusion (left panel) and pre- to post-transfusion (right panel) in patients receiving RBC transfusion starting at Hb <7.5 g/dL, 7.5–8.5 g/dL, or >8.5 g/dL. Data were analyzed using one-way ANOVA and expressed as mean ± SD (<7.5, n = 21; 7.5–8.5, n = 21; >8.5, n = 25; lines indicate significant post-transfusion differences between groups; p < 0.01).

Fig. 5. Systolic, mean, and diastolic blood pressures assessed pre- and post-transfusion in patients receiving RBC transfusion starting at Hb <7.5 g/dL, 7.5–8.5 g/dL, or >8.5 g/dL. Data were analyzed using two-way ANOVA with Bonferroni post hoc analyses and expressed as mean ± SD (<7.5 g/dL, n = 21; 7.5–8.5 g/dL, n = 21; >8.5 g/dL, n = 25; lines indicate significant differences between pre- and post-transfusion; p < 0.01).