Table 3.

Unadjusted and adjusted odds ratios of intraoperative reduction of rSO₂ of each cut-offs for postoperative delirium

Intraoperative rSO2	Unadjusted OR (95% CI)	P-values	Adjusted OR (95% CI)	P-values
Mean	0.985 (0.957 to 1.014)	0.32	0.976 (0.942 to 1.011)	0.18
Minimum	0.987 (0.962 to 1.012)	0.30	0.977 (0.948 to 1.006)	0.12
Duration of rSO2 reduction (for every 5 min)
< 75%	1.004 (0.997 to 1.010)	0.27	1.006 (0.999 to 1.013)	0.12
< 70%	1.004 (0.997 to 1.010)	0.28	1.005 (0.998 to 1.012)	0.14
< 65%	1.003 (0.997 to 1.009)	0.36	1.004 (0.997 to 1.011)	0.24
< 60%	1.003 (0.998 to 1.008)	0.25	1.004 (0.998 to 1.010)	0.16
< 55%	1.003 (0.998 to 1.008)	0.20	1.004 (0.999 to 0.010)	0.15
< 50%	1.006 (1.001 to 1.011)	0.03	1.007 (1.001 to 1.014)	0.02
< 45%	1.009 (1.001 to 1.017)	0.03	1.012 (1.003 to 1.021)	0.01
< 40%	1.009 (0.994 to 1.025)	0.26	1.013 (0.995 to 1.030)	0.15
< 35%	1.011 (0.986 to 1.037)	0.38	1.021 (0.990 to 1.053)	0.19
Occurrence of rSO2 reduction
< 70%	.	1	.	1
< 65%	1.036 (0.126 to 8.502)	0.97	.	1
< 60%	0.858 (0.374 to 1.966)	0.72	1.460 (0.423 to 5.044)	0.55
< 55%	0.956 (0.572 to 1.598)	0.87	0.935 (0.492 to 1.777)	0.84
< 50%	1.427 (0.929 to 2.192)	0.11	1.599 (0.965 to 2.649)	0.07
< 45%	1.525 (1.003 to 2.317)	0.048	1.737 (1.064 to 2.836)	0.03
< 40%	1.077 (0.616 to 1.882)	0.80	1.236 (0.657 to 2.326)	0.51
< 35%	0.989 (0.409 to 2.390)	0.98	0.839 (0.306 to 2.299)	0.73

rSO₂ Regional cerebral oxygen saturation, OR Odds ratio, CI Confidence interval