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

Table 1 Comparison of baseline characteristics between two groups, n (%)/mean ± SD

Parameter	Goal-directed fluid therapy group (n = 110)	Conventional fluid therapy group (n = 110)	Statistic	P value
General information
Age (years)	68.3 ± 5.7	67.9 ± 6.1	t = 0.497	0.620
Sex (male/female)	60/50	58/52	χ² = 0.074	0.786
Male	60 (54.5)	58 (52.7)
Body mass index (kg/m²)	24.2 ± 3.1	23.9 ± 3.3	t = 0.684	0.495
Years of education	9.8 ± 3.2	10.1 ± 3.5	t = 0.648	0.518
American Society of Anesthesiologists classification			χ² = 0.385	0.825
Class I	18 (16.4)	20 (18.2)
Class II	67 (60.9)	64 (58.2)
Class III	25 (22.7)	26 (23.6)
Medical history
Hypertension	52 (47.3)	55 (50.0)	χ² = 0.162	0.687
Diabetes mellitus	28 (25.5)	31 (28.2)	χ² = 0.215	0.643
Coronary heart disease	15 (13.6)	18 (16.4)	χ² = 0.347	0.556
Surgical information
Surgical type			χ² = 0.165	0.685
Abdominal surgery	66 (60.0)	69 (62.7)
Orthopedic surgery	44 (40.0)	41 (37.3)
Surgical duration (hours)	3.2 ± 0.8	3.1 ± 0.9	t = 0.856	0.393
Anesthesia duration (hours)	3.8 ± 0.9	3.7 ± 1.0	t = 0.767	0.444
Estimated blood loss (mL)	385 ± 125	392 ± 138	t = 0.388	0.698
Anxiety-depression assessment
Anxiety-depression	45 (40.9)	47 (42.7)	χ² = 0.071	0.791
HADS-A scorec
Anxiety-depression subgroup	10.3 ± 2.0	10.1 ± 2.2	t = 0.448	0.655
Non-anxiety-depression subgroup	4.2 ± 1.7	4.4 ± 1.9	t = 0.588	0.558
HADS-D scorec
Anxiety-depression subgroup	9.9 ± 2.2	9.7 ± 2.4	t = 0.409	0.683
Non-anxiety-depression subgroup	3.8 ± 1.5	4.0 ± 1.7	t = 0.665	0.507
Preoperative cognitive assessment
Mini-Mental State Examination score	27.8 ± 1.6	27.6 ± 1.7	t = 0.929	0.354
Anxiety-depression subgroup	27.1 ± 1.8	27.3 ± 1.9	t = 0.508	0.613
Non-anxiety-depression subgroup	28.2 ± 1.3	28.0 ± 1.5	t = 0.768	0.444
Montreal Cognitive Assessment score	25.1 ± 2.3	24.9 ± 2.4	t = 0.660	0.509
Anxiety-depression subgroup	24.2 ± 2.6	24.4 ± 2.4	t = 0.375	0.709
Non-anxiety-depression subgroup	25.6 ± 2.0	25.4 ± 2.2	t = 0.510	0.611
Preoperative laboratory tests
Hemoglobin (g/L)	128.5 ± 16.3	130.2 ± 17.8	t = 0.740	0.460
Albumin (g/L)	38.6 ± 4.2	39.1 ± 4.5	t = 0.858	0.392
Serum creatinine (μmol/L)	78.3 ± 18.5	76.9 ± 19.2	t = 0.549	0.584
Fasting glucose (mmol/L)	5.8 ± 1.2	5.9 ± 1.3	t = 0.596	0.552

^cP < 0.001.

Comparison of Hospital Anxiety and Depression Scale score between anxiety-depression and non-anxiety-depression subgroups, P < 0.001; baseline Mini-Mental State Examination and Montreal Cognitive Assessment score were lower in patients with anxiety-depression compared to those without, P < 0.05. HADS-A: Hospital Anxiety and Depression Scale-anxiety subscale; HADS-D: Hospital Anxiety and Depression Scale-depression subscale.

Table 2 Comparison of perioperative hemodynamics and fluid management between two groups, n (%)/mean ± SD

Parameter	Goal-directed fluid therapy group (n = 110)	Conventional fluid therapy group (n = 110)	Statistic	P value
Hemodynamic parameters
Preoperative MAP (mmHg)	92.3 ± 10.5	91.8 ± 11.2	t = 0.344	0.731
Preoperative HR (beats/minute)	72.5 ± 9.8	73.2 ± 10.3	t = 0.513	0.608
Intraoperative mean MAP (mmHg)	78.6 ± 6.8	76.2 ± 8.5	t = 2.296	0.023
Intraoperative mean HR (beats/minute)	68.3 ± 8.5	70.8 ± 9.7	t = 2.025	0.044
Intraoperative mean cardiac output (L/minute)	4.8 ± 0.7	4.3 ± 0.8	t = 4.971	< 0.001
Hypotensive events
Number of hypotensive episodes	2.1 ± 1.3	3.8 ± 2.1	t = 7.157	< 0.001
Duration of hypotension (minutes)	8.3 ± 5.2	15.7 ± 8.6	t = 7.569	< 0.001
Incidence of hypotension	56 (50.9)	78 (70.9)	χ² = 9.091	0.003
Vasoactive agent use
Vasoactive agent use	48 (43.6)	69 (62.7)	χ² = 7.950	0.005
Phenylephrine use	38 (34.5)	58 (52.7)	χ² = 7.372	0.007
Ephedrine use	22 (20.0)	35 (31.8)	χ² = 3.951	0.047
Dopamine use	5 (4.5)	8 (7.3)	χ² = 0.729	0.393
Fluid management
Total intraoperative fluid (mL)	2180 ± 420	2650 ± 580	t = 6.849	< 0.001
Standardized fluid volume (mL/kg/hour)	6.8 ± 1.2	8.3 ± 1.8	t = 7.302	< 0.001
Crystalloid infusion (mL)	1560 ± 340	2050 ± 480	t = 8.894	< 0.001
Colloid infusion (mL)	620 ± 160	600 ± 180	t = 0.873	0.383
Colloid proportion (%)	28.3 ± 8.5	22.6 ± 9.2	t = 4.815	< 0.001
Hydroxyethyl starch use	76 (69.1)	71 (64.5)	χ² = 0.502	0.478
Albumin use	15 (13.6)	12 (10.9)	χ² = 0.382	0.537
Fluid input/output
Intraoperative blood loss (mL)	420 ± 185	445 ± 205	t = 0.946	0.345
Intraoperative urine output (mL)	785 ± 235	760 ± 258	t = 0.755	0.451
Standardized urine output (mL/kg/hour)	1.2 ± 0.3	1.1 ± 0.4	t = 1.326	0.186
Intraoperative positive fluid balance (mL)	980 ± 310	1450 ± 480	t = 8.600	< 0.001
24 hours cumulative fluid input (mL)	3420 ± 680	4180 ± 890	t = 7.185	< 0.001
24 hours cumulative urine output (mL)	1770 ± 420	1900 ± 510	t = 2.033	0.043
24 hours fluid balance (mL)	1650 ± 520	2280 ± 690	t = 7.460	< 0.001
Transfusion
Patients receiving transfusion	18 (16.4)	23 (20.9)	χ² = 0.745	0.388
Red blood cell transfusion (U)	1.8 ± 0.9	2.1 ± 1.1	t = 1.124	0.264
Plasma transfusion (mL)	285 ± 125	310 ± 145	t = 0.684	0.495

Hypotension defined as mean arterial pressure < 65 mmHg. HR: Heart rate; MAP: Mean arterial pressure.

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.

Table 4 Multivariate logistic regression analysis: Risk factors for postoperative cognitive dysfunction on postoperative day 1

Variable	Univariate analysis		Multivariate analysis
	OR (95%CI)	P value	Adjusted OR (95%CI)	P value
Age (per 5-year increase)	1.32 (1.08-1.62)	0.007	1.28 (1.04-1.58)	0.021
Male sex	0.87 (0.51-1.48)	0.609	-	-
American Society of Anesthesiologists class ≥ III	1.68 (0.88-3.21)	0.116	1.45 (0.73-2.88)	0.289
Surgical duration (per 1 hour increase)	1.42 (1.06-1.91)	0.019	1.35 (0.99-1.84)	0.056
Preoperative anxiety-depression	2.89 (1.67-5.01)	< 0.001	2.68 (1.52-4.73)	0.001
Fluid therapy modality (conventional fluid therapy vs goal-directed fluid therapy)	2.35 (1.36-4.06)	0.002	2.12 (1.20-3.75)	0.010
Regional cerebral oxygen saturation decline magnitude (per 5% increase)	1.52 (1.28-1.81)	< 0.001	1.43 (1.18-1.74)	< 0.001
Intraoperative hypotension duration (per 10 minutes increase)	1.38 (1.12-1.70)	0.003	1.26 (1.01-1.57)	0.042

OR: Odds ratio.

Table 5 Relationship between regional cerebral oxygen saturation decline magnitude and postoperative cognitive dysfunction across subgroups

Subgroup	Adjusted odds ratio (95%CI)	P value	Interaction P value
Age stratification			0.156
< 70 years (n = 118)	1.38 (1.08-1.76)	0.009
≥ 70 years (n = 102)	1.52 (1.20-1.93)	< 0.001
Sex stratification			0.524
Male (n = 118)	1.41 (1.10-1.80)	0.006
Female (n = 102)	1.46 (1.14-1.87)	0.003
Anxiety-depression stratification			0.042
Non-anxiety-depression (n = 128)	1.35 (1.05-1.73)	0.022
Anxiety-depression (n = 92)	1.58 (1.25-2.00)	< 0.001
Fluid management strategy stratification			0.187
Goal-directed fluid therapy group (n = 110)	1.31 (1.02-1.68)	0.032
Conventional fluid therapy group (n = 110)	1.48 (1.19-1.84)	0.001
ASA classification stratification			0.428
ASA I and II (n = 169)	1.40 (1.13-1.74)	0.002
ASA III (n = 51)	1.52 (1.10-2.10)	0.012

ASA: American Society of Anesthesiologists.