Electroencephalogram-guided anesthesia and postoperative anxiety and depression in elderly gastric cancer patients with sleep disorders

Table 1 Comparison of baseline characteristics between the two groups, n (%)

Characteristics	Electroencephalogram group (n = 118)	Control group (n = 122)	Statistical value	P value
Demographic characteristics
Age (years) (mean ± SD)	72.3 ± 5.7	71.8 ± 6.1	t = 0.642	0.521
Gender			χ² = 0.039	0.843
Male	75 (63.6)	79 (64.8)
Female	43 (36.4)	43 (35.2)
Body mass index (kg/m²) (mean ± SD)	23.5 ± 2.8	23.2 ± 3.0	t = 0.779	0.437
Clinical characteristics
American Society of Anesthesiologists classification			χ² = 0.415	0.520
Grade II	72 (61.0)	69 (56.6)
Grade III	46 (39.0)	53 (43.4)
Comorbidities
Hypertension	55 (46.6)	59 (48.4)	χ² = 0.074	0.786
Diabetes	36 (30.5)	40 (32.8)	χ² = 0.146	0.702
Coronary heart disease	26 (22.0)	30 (24.6)	χ² = 0.221	0.639
Preoperative laboratory tests
Hemoglobin (g/L) (mean ± SD)	118.5 ± 13.2	116.8 ± 14.5	t = 0.946	0.345
Albumin (g/L) (mean ± SD)	36.8 ± 3.5	37.2 ± 3.3	t = -0.897	0.371
Tumor characteristics
TNM staging			χ² = 0.378	0.828
Stage I	32 (27.1)	30 (24.6)
Stage II	51 (43.2)	53 (43.4)
Stage III	35 (29.7)	39 (32.0)
Tumor location			χ² = 0.267	0.875
Cardia	28 (23.7)	31 (25.4)
Body	45 (38.1)	43 (35.2)
Antrum	45 (38.1)	48 (39.3)
Differentiation degree			χ² = 0.199	0.905
Well differentiated	21 (17.8)	19 (15.6)
Moderately differentiated	62 (52.5)	66 (54.1)
Poorly differentiated	35 (29.7)	37 (30.3)
Surgery-related
Surgical approach			χ² = 0.018	0.892
Open	69 (58.5)	72 (59.0)
Laparoscopic	49 (41.5)	50 (41.0)
Preoperative assessment
PSQI total score (mean ± SD)	9.8 ± 2.6	10.1 ± 2.4	t = -0.904	0.367
PSQI component scores (mean ± SD)
Sleep quality	1.8 ± 0.6	1.9 ± 0.5	t = -0.823	0.411
Sleep latency	1.7 ± 0.7	1.8 ± 0.6	t = -0.736	0.463
Sleep duration	1.6 ± 0.5	1.7 ± 0.6	t = -0.871	0.385
Sleep efficiency	1.5 ± 0.6	1.6 ± 0.5	t = -0.802	0.424
Sleep disturbances	1.9 ± 0.4	1.8 ± 0.5	t = 0.645	0.520
Use of sleep medication	0.5 ± 0.8	0.6 ± 0.7	t = -0.600	0.549
Daytime dysfunction	1.7 ± 0.6	1.8 ± 0.5	t = -0.851	0.395
HADS scores (mean ± SD)
Anxiety subscale (HADS-A)	5.8 ± 1.9	5.7 ± 2.0	t = 0.401	0.689
Depression subscale (HADS-D)	6.0 ± 1.8	5.9 ± 1.7	t = 0.444	0.657

HADS: Hospital Anxiety and Depression Scale; PSQI: Pittsburgh Sleep Quality Index.

Table 2 Multivariate analysis results for postoperative psychological outcomes

Variable	Odds ratio	95%CI	P value
Protective factors
Electroencephalogram-guided individualized anesthesia	0.56	0.41-0.78	0.003
Reasonable preoperative psychological preparation	0.65	0.45-0.94	0.022
Good postoperative pain control (resting Visual Analog Scale < 4)	0.74	0.53-1.02	0.067
Risk factors
Preoperative psychological factors
Preoperative Hospital Anxiety and Depression Scale score ≥ 8	2.15	1.42-3.26	< 0.001
Preoperative PSQI score ≥ 10	1.87	1.26-2.78	0.002
Individual PSQI components
Poor sleep efficiency (≤ 75%)	2.24	1.48-3.39	< 0.001
Frequent sleep disturbances (≥ 2.5 points)	1.95	1.32-2.88	0.001
Patient-related factors
Age ≥ 75 years	1.43	1.02-2.01	0.038
American Society of Anesthesiologists III	1.39	0.97-1.98	0.072
Intraoperative factors
Intraoperative hypotension	1.75	1.18-2.61	0.006
Operation time > 3 hours	1.68	1.13-2.49	0.010
Intraoperative blood loss > 300 mL	1.52	1.06-2.17	0.021
Intraoperative temperature < 36.0 °C	1.46	1.05-2.03	0.024

Variables with P ≥ 0.05 indicate non-significant trends. The analysis included individual Pittsburgh Sleep Quality Index components to identify specific sleep disorder patterns most predictive of postoperative psychological outcomes. PSQI: Pittsburgh Sleep Quality Index.

Table 3 Gradient effect of electroencephalogram-guided anesthesia on postoperative psychological outcomes across sleep disorder severity spectrum, mean ± SD

Sleep disorder severity	Measure	Electroencephalogram group	Control group	t value	P value
Severe	HADS-A	5.9 ± 1.8	8.6 ± 2.1	-5.32	< 0.001
	HADS-D	6.4 ± 1.6	8.2 ± 1.9	-4.06	< 0.001
	HADS total	12.3 ± 3.1	16.8 ± 3.4	-5.48	< 0.001
Moderate	HADS total	10.7 ± 2.9	14.2 ± 3.2	-5.67	< 0.001
Mild	HADS-A	4.5 ± 1.7	5.3 ± 1.9	-2.04	0.045
	HADS-D	5.0 ± 1.5	6.4 ± 1.7	-4.03	< 0.001
	HADS total	9.5 ± 2.6	11.7 ± 2.8	-3.64	0.023

HADS: Hospital Anxiety and Depression Scale.

Table 4 Comparison of postoperative complications and recovery between electroencephalogram and control groups, n (%)

Outcome	Electroencephalogram group (n = 118)	Control group (n = 122)	Statistic	P value
Postoperative complications
Overall complication rate	38 (32.2)	59 (48.4)	χ² = 6.72	0.010
Postoperative delirium	10 (8.5)	21 (17.2)	χ² = 4.31	0.038
Duration of delirium (days) (mean ± SD)	1.7 ± 0.6	2.5 ± 0.9	t = -2.62	0.014
Postoperative nausea and vomiting	30 (25.4)	46 (37.7)	χ² = 4.27	0.039
Number of vomiting episodes (mean ± SD)	1.3 ± 0.6	2.2 ± 1.0	t = -5.05	< 0.001
Perioperative hypotension	16 (13.6)	30 (24.6)	χ² = 4.85	0.028
Pulmonary infection	6 (5.1)	15 (12.3)	χ² = 3.92	0.048
Wound infection	7 (5.9)	9 (7.4)	χ² = 0.19	0.659
Urinary tract infection	4 (3.4)	7 (5.7)	χ² = 0.76	0.384
Pain management
POD1 VAS score (at rest) (mean ± SD)	3.2 ± 1.1	3.9 ± 1.3	t = -4.65	< 0.001
POD1 VAS score (with movement) (mean ± SD)	5.1 ± 1.4	5.8 ± 1.5	t = -3.73	< 0.001
POD2 VAS score (at rest) (mean ± SD)	2.5 ± 0.9	3.0 ± 1.1	t = -3.89	< 0.001
POD2 VAS score (with movement) (mean ± SD)	4.2 ± 1.3	4.9 ± 1.4	t = -4.02	< 0.001
POD3 VAS score (at rest) (mean ± SD)	1.9 ± 0.8	2.3 ± 1.0	t = -3.46	0.001
POD3 VAS score (with movement) (mean ± SD)	3.6 ± 1.1	4.1 ± 1.2	t = -3.34	0.001
Cumulative analgesic consumption (morphine equivalent mg) (mean ± SD)	45.3 ± 12.8	58.7 ± 16.2	t = -7.24	< 0.001
Gastrointestinal recovery
Time to first bowel sounds (hours) (mean ± SD)	46.5 ± 12.8	53.2 ± 14.5	t = -3.82	< 0.001
Time to first flatus (hours) (mean ± SD)	62.3 ± 15.6	70.8 ± 16.9	t = -4.04	< 0.001
Time to first liquid diet (days) (mean ± SD)	3.5 ± 1.2	4.3 ± 1.5	t = -4.53	< 0.001
Early ambulation
Time to first out-of-bed activity (hours) (mean ± SD)	26.8 ± 7.6	32.5 ± 9.2	t = -5.21	< 0.001
6-minute walking test on POD3 (m) (mean ± SD)	152.6 ± 45.8	128.3 ± 40.6	t = 4.28	< 0.001
Hospitalization outcomes
Total length of stay (days) (mean ± SD)	12.6 ± 3.2	14.8 ± 3.5	t = -5.05	0.012
Postoperative length of stay (days) (mean ± SD)	10.8 ± 2.7	12.5 ± 3.0	t = -4.58	< 0.001
30-day readmission rate	4 (3.4)	8 (6.6)	χ² = 1.29	0.256

POD: Postoperative day; VAS: Visual Analog Scale.