Goal-directed fluid therapy and cognitive outcomes in elderly surgical patients with anxiety and depression

Table 3 Comparison of perioperative cerebral oxygen saturation changes between two groups, n (%)/mean ± SD

Parameter	Goal-directed fluid therapy group (n = 110)	Conventional fluid therapy group (n = 110)	Statistic	P value
Overall rSO2 changes
Baseline rSO2 (%)	68.2 ± 6.3	67.8 ± 6.7	t = 0.481	0.631
Minimum intraoperative rSO2 (%)	61.5 ± 5.8	56.3 ± 7.2	t = 5.845	< 0.001
The rSO2 decline magnitude (%)	9.8 ± 4.2	16.9 ± 6.5	t = 9.550	< 0.001
The rSO2 at surgery completion (%)	66.8 ± 5.9	63.2 ± 7.1	t = 4.054	< 0.001
The rSO2 recovery rate (%)	97.9 ± 4.8	93.2 ± 7.3	t = 5.779	< 0.001
Cerebral oxygen supply-demand imbalance events
The rSO2 decline ≥ 20%	14 (12.7)	38 (34.5)	χ² = 15.886	< 0.001
Absolute rSO2 < 50%	6 (5.5)	20 (18.2)	χ² = 8.916	0.003
The rSO2 < 80% baseline	28 (25.5)	56 (50.9)	χ² = 15.119	< 0.001
Patients with cerebral oxygen imbalance	32 (29.1)	62 (56.4)	χ² = 16.482	< 0.001
Duration of low rSO2
Low rSO2 duration (minutes)	12.5 ± 6.8	23.7 ± 11.3	t = 5.894	< 0.001
Duration > 20 minutes	5 (15.6)	32 (51.6)	χ² = 12.163	< 0.001
Duration 10-20 minutes	18 (56.3)	22 (35.5)	χ² = 3.545	0.060
Duration < 10 minutes	9 (28.1)	8 (12.9)	χ² = 2.902	0.088
Anxiety-depression subgroup analysis
Patients with anxiety-depression (n = 92)	n = 45	n = 47
Baseline rSO2 (%)	67.5 ± 6.8	67.2 ± 7.1	t = 0.211	0.833
Minimum intraoperative rSO2 (%)	60.9 ± 6.2	54.2 ± 7.8	t = 4.541	< 0.001
The rSO2 decline magnitude (%)	10.8 ± 4.6	19.3 ± 7.1	t = 6.791	< 0.001
The rSO2 decline ≥ 20%	7 (15.6)	22 (46.8)	χ² = 10.406	0.001
Cerebral oxygen imbalance rate	16 (35.6)	32 (68.1)	χ² = 9.784	0.002
Patients without anxiety-depression (n = 128)	n = 65	n = 63
Baseline rSO2 (%)	68.7 ± 5.9	68.2 ± 6.4	t = 0.459	0.647
Minimum intraoperative rSO2 (%)	61.9 ± 5.5	57.8 ± 6.5	t = 3.869	< 0.001
The rSO2 decline magnitude (%)	9.1 ± 3.7	15.2 ± 5.6	t = 7.420	< 0.001
The rSO2 decline ≥ 20%	7 (10.8)	16 (25.4)	χ² = 4.296	0.038
Cerebral oxygen imbalance rate	16 (24.6)	30 (47.6)	χ² = 7.173	0.007

Regional cerebral oxygen saturation decline magnitude = [(baseline value - minimum value)/baseline value] × 100%. Regional cerebral oxygen saturation recovery rate = (value at surgery completion/baseline value) × 100%; statistics include only patients with cerebral oxygen supply-demand imbalance. rSO₂: Regional cerebral oxygen saturation.