Effects of Remote Ischemic Preconditioning on Postoperative Cognitive Dysfunction in Elderly Patients with Laparoscopic Cholecystectomy

Figures & data

Table 1 Demographic Characteristics and Perioperative Data

Variable	Control Group (n = 44)	RIPC Group (n = 44)	P value
Age, years	69.23±2.01	68.82±2.41	0.39
Sex (male, %)	15(34)	21(47)	0.19
BMI (kg/m^2)	23.92±3.18	23.91±2.80	0.98
ASA, II/III	20/24	21/23	0.83
Educational level			0.94
Primary, n(%)	2(5)	3(7)
Junior high school, n(%)	18(41)	17(39)
Senior high school, n(%)	19(43)	20(45)
College degree, n(%)	5(11)	4(9)
Smoking history, n(%)	8(18)	10(23)	0.59
Drinking history, n(%)	3(6)	2(4)	0.64
Hypertension, n(%)	31(70)	33(75)	0.63
Coronary heart disease, n(%)	5(11)	6(13)	0.74
Diabetes, n(%)	4(9)	5(11)	0.72
Lactated Ringer solution (mL)	826.36±208.40	807.05±185.10	0.65
Intraoperative bleeding (mL)	5.73±2.20	5.32±2.13	0.38
Anesthesia duration (min)	72.75±15.26	75.39±19.51	0.48
Pneumoperitoneum pressure	13(12,14)	13(12,14)	0.53
Surgery duration (min)	104.27±27.00	103.32±24.72	0.86
Length of stay (day)	6.86±1.52	6.66±1.74	0.56

Note: Data are expressed as mean ± SD or number or median (interquartile range) (%).

Abbreviations: RIPC Group, Remote ischemic preconditioning group; BMI, Body mass index; ASA, American Society of Anesthesiologists.

Figure 1 Flow chart of the study inclusion process.

Table 2 Z Score in Each Neuropsychological Test

		Control Group (n = 44)	RIPC Group (n =44)	P value
MMSE	T0	25.05±1.41	25.32±1.43	0.37
	T6	24.55±1.53	24.80±1.58	0.45
PRT
PRT-A	T0	5.16±1.10	4.98±0.90	0.40
	T6	5.05±1.10	4.95±1.12	0.70
PRT-B	T0	5.16±1.12	5.09±1.18	0.78
	T6	5.18±1.15	5.00±0.99	0.43
PRT-C	T0	5.02±1.19	5.00±1.24	0.93
	T6	5.00±1.08	5.05±1.14	0.85
Stroop test
Stroop test-A	T0	29.05±2.98	28.50±2.73	0.37
	T6	29.36±2.55	28.91±3.09	0.45
Stroop test-B	T0	50.59±3.66	50.27±3.68	0.69
	T6	50.61±4.61	50.39±4.44	0.81
Stroop test-C	T0	113.00±6.70	110.18±7.70	0.07
	T6	115.86±7.06	110.91±8.69*	0.01
NCT	T0	47.84±5.81	48.25±5.92	0.74
	T6	49.52±5.51	49.70±5.82	0.88
DST	T0	211.86±22.15	212.27±19.70	0.93
	T6	213.80±21.36	211.86±23.10	0.69
DSST	T0	15.23±2.44	15.50±2.42	0.60
	T6	16.11±2.05	15.89±2.17	0.62

Notes: Data are expressed as mean ± SD. *P < 0.05, vs the Control group.

Abbreviations: RIPC, Remote ischemic preconditioning; MMSE, Mini-mental state examination; PRT, Picture recall test; Stroop Test, Stroop the color test; NCT, Number connecting test; DST, Digit-symbol test; DSST, Digit symbol substitution test.

Figure 2 A histogram of the number of POCD and healthy people in both groups. *P<0.05, vs the Control group.

Abbreviation: POCD, Postoperative cognitive dysfunction.

Table 3 Surgery-Related Data

		Control Group (n = 44)	RIPC Group (n = 44)	P value
MAP (mmHg)	T1	94.39±9.05	93.73±9.08	0.73
	T2	81.98±7.62	82.02±4.23	0.97
	T3	79.48±6.53	81.14±3.05	0.13
	T4	87.59±7.04	85.45±3.62	0.07
HR (bpm)	T1	86.00 (85.00, 88.75)	88.00 (83.00, 89.00)	0.91
	T2	63.00 (60.00, 65.00)	62.00 (61.00, 66.75)	0.91
	T3	60.00 (55.25, 69.00)	59.00 (55.00, 64.75)	0.16
	T4	68.00 (65.00, 72.00)	67.00 (63.00, 74.00)	0.26
PaO2 (mmHg)	T1	87.0 (81.00, 91.00)	88.0 (82.50, 90.75)	0.58
	T2	156.5 (129.50, 186.75)	161.5 (145.50, 184.50)	0.36
	T3	133.0 (117.75, 166.50)	135.0 (116.25, 196.75)	0.43
	T4	111.0 (100.25, 130.75)	113.0 (101.00, 134.00)	0.54
PaCO2 (mmHg)	T1	38.0 (35.00, 39.00)	38.0 (36.00, 39.00)	0.52
	T2	38.0 (36.00, 39.75)	39.0 (36.00, 42.00)	0.27
	T3	40.0 (39.00, 42.75)	40.5 (38.00, 45.00)	0.67
	T4	39.0 (36.00, 44.00)	40.0 (38.00, 43.00)	0.59
Lac (mg/dL)	T1	1.30 (1.20, 1.68)	1.30 (1.20, 1.58)	0.78
	T2	0.90 (0.80, 1.28)	0.90 (0.73, 1.40)	0.73
	T3	0.90 (0.70, 1.20)	0.90 (0.80, 1.20)	0.79
	T4	0.85 (0.70, 1.10)	0.85 (0.60, 1.30)	0.83
Hb (g/L)	T1	12.82±1.61	13.26±1.60	0.21
	T2	12.46±1.61	12.45±1.61	0.98
	T3	12.22±1.61	12.58±1.47	0.27
	T4	12.43±1.65	12.89±1.33	0.19
Glu (mmol/L)	T1	5.97±0.80	5.81±1.08	0.41
	T2	6.43±1.01	6.25±1.34	0.48
	T3	7.01±1.27	6.86±1.44	0.62
	T4	7.44±1.59	7.21±1.70	0.51

Note: Data are presented as mean ± SD or median (interquartile range).

Abbreviations: RIPC, Remote ischemic preconditioning; MAP, Mean arterial pressure; HR, Heart rate; Lac, Lactic acid; Hb, Hemoglobin; Glu, Glucose.

Figure 3 Line chart of rSO₂ changes at different time points. *P<0.001, vs the Control group. ^##P<0.001, vs baseline in either group.

Abbreviation: rSO₂, Regional cerebral oxygen saturation.

Figure 4 Changes in NSE and BDNF (mean ± SD) between the two groups. *P<0.001, vs the Control group. ^##P<0.001, vs baseline in either group.

Abbreviations: NSE, Neuron-specific Enolase; BDNF, Brain-Derived Neurotrophic Factor.

Table 4 Correlation Analysis of rSO₂ and Neuropsychological Tests

Test	MMSE	PRT-A	PRT-B	PRT-V	Stroop Test-A	Stroop Test-B	Stroop Test-C	NCT	DST	DSST
rSO2
r	0.08	0.09	0.14	−0.04	−0.02	−0.06	−0.07	−0.05	−0.05	0.08
p	0.46	0.43	0.21	0.75	0.84	0.55	0.54	0.67	0.64	0.48

Table 5 Correlation Analysis of MMSE and Serological Indexes

Index	NSE	BDNF
MMSE
r	−0.02	−0.15
p	0.86	0.17