J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website https://jocmr.elmerjournals.com

Original Article

Volume 17, Number 3, March 2025, pages 145-152

Effect of Ascorbic Acid on the Incidence of Postoperative Delirium Among Elderly Patients Undergoing Cardiovascular Surgery: A Pilot Study

Figure 1. Flow chart depicting patient enrolment. CPB: cardiopulmonary bypass; CABG: coronary artery bypass graft.

Figure 3. Distribution of EuroSCORE II and the incidence of postoperative delirium (POD). EuroSCORE II: European System for Cardiac Operative Risk Evaluation II.

**Table 1.** Patient Characteristics
	Overall	Delirium (-)	Delirium (+)	P value
Values are shown as median (25th - 75th percentile), mean (± standard deviation), or numbers. ^aMini-Mental State examination was evaluated in 46 patients. NYHA: New York Heart Association; EuroSCORE: European System for Cardiac Operative Risk Evaluation; MAP: mean arterial pressure; CPB: cardiopulmonary bypass; BIS: Bispectral Index; APACHE II: Acute Physiology and Chronic Health Evaluation II; ICU: intensive care unit; POD: postoperative delirium.
N	48	32	16
Age (years)	77 (74 - 81)	76 (73 - 79)	80 (74 - 83)	0.06
Sex (male, female)	32, 16	20,12	12,4	0.4
Height (cm)	160 ± 8.6	159 ± 9.2	160 ± 7.7	0.8
Weight (kg)	57 ± 12	58 ± 11	54 ± 12	0.22
Mini-Mental State Examination^a	29 (26 - 30)	29 (27.5 - 30)	28 (23.5 - 29)	0.06
Hypertension (n)	39	25	14	0.45
Diabetes mellitus (n)	13	8	5	0.66
Dyslipidemia (n)	24	16	8	1
Past cerebral infarction (n)	5	3	2	0.78
NYHA functional status III/IV (n)	5	1	4	0.02
Main Procedure (n)				0.01
Valve surgery	38	29	9
Aortic surgery	4	0	4
Coronary artery bypass grafting	0	0	0
Composite surgery	6	3	3
EuroSCOREII (%)	4.28 (1.9 - 7.39)	3.45 (1.56 - 4.85)	8.40 (5.94 - 10.7)	< 0.001
Preoperative plasma level of ascorbic acid (µg/mL)	5.47 ± 2.2	6.08 ± 2.33	4.25 ± 1.26	0.005
CPB time (min)	140 (105 - 176)	119 (92 - 168)	155 (134 - 181)	0.03
Operation time (min)	296 (248 - 337)	271 (232 - 318)	316 (300 - 364)	0.006
Intraoperative MAP less than 60 mm Hg (except during CPB) (min)	59 ± 34	59 ± 34	59 ± 35	0.99
Intraoperative BIS (except during CPB)	45 (40 - 50)	46 (41 - 52)	42 (38 - 47)	< 0.001
Fluid balance during the operation (mL)	4,083 ± 1,664	3,774 ± 1,558	4,700 ± 1,748	0.07
APACHEII score at ICU admission	17 ± 3.8	17 ± 3.6	17 ± 4.5	0.9
APACHEIII score at ICU admission	63 ± 14	60 ± 13	68 ± 16	0.1
Postoperative plasma level of ascorbic acid (µg/mL) (n = 34)	19.1 ± 8.1	17.3 ± 5.6	22.1 ± 10.7	0.09
Postoperative cerebral infarction (n)	3	0	3	0.01
Fluid balance in first 48 h in ICU (mL)	1,361 ± 1,915	1,063 ± 1,720	1,957 ± 2,192	0.13
The use of dexmedetomidine before the development of POD (n)	8	6	2	0.6
Intubation time (h)	13 (7.9 - 22.7)	11 (7.5 - 16.6)	23 (8.6 - 89.5)	0.03
Length of ICU stay (h)	94 (88 - 163)	93 (91 - 117)	165 (82 - 222)	0.03
Incidence of POD	33%	-	-	-
Duration of POD (h)	-	-	19.9 (11.3 - 59.5)	-

Table 1. Patient Characteristics

Overall

Delirium (-)

Delirium (+)

P value

Values are shown as median (25th - 75th percentile), mean (± standard deviation), or numbers. ^aMini-Mental State examination was evaluated in 46 patients. NYHA: New York Heart Association; EuroSCORE: European System for Cardiac Operative Risk Evaluation; MAP: mean arterial pressure; CPB: cardiopulmonary bypass; BIS: Bispectral Index; APACHE II: Acute Physiology and Chronic Health Evaluation II; ICU: intensive care unit; POD: postoperative delirium.

Age (years)

77 (74 - 81)

76 (73 - 79)

80 (74 - 83)

0.06

Sex (male, female)

32, 16

20,12

12,4

0.4

Height (cm)

160 ± 8.6

159 ± 9.2

160 ± 7.7

0.8

Weight (kg)

57 ± 12

58 ± 11

54 ± 12

0.22

Mini-Mental State Examination^a

29 (26 - 30)

29 (27.5 - 30)

28 (23.5 - 29)

0.06

Hypertension (n)

0.45

Diabetes mellitus (n)

0.66

Dyslipidemia (n)

Past cerebral infarction (n)

0.78

NYHA functional status III/IV (n)

0.02

Main Procedure (n)

0.01

Valve surgery

Aortic surgery

Coronary artery bypass grafting

Composite surgery

EuroSCOREII (%)

4.28 (1.9 - 7.39)

3.45 (1.56 - 4.85)

8.40 (5.94 - 10.7)

< 0.001

Preoperative plasma level of ascorbic acid (µg/mL)

5.47 ± 2.2

6.08 ± 2.33

4.25 ± 1.26

0.005

CPB time (min)

140 (105 - 176)

119 (92 - 168)

155 (134 - 181)

0.03

Operation time (min)

296 (248 - 337)

271 (232 - 318)

316 (300 - 364)

0.006

Intraoperative MAP less than 60 mm Hg (except during CPB) (min)

59 ± 34

59 ± 35

0.99

Intraoperative BIS (except during CPB)

45 (40 - 50)

46 (41 - 52)

42 (38 - 47)

< 0.001

Fluid balance during the operation (mL)

4,083 ± 1,664

3,774 ± 1,558

4,700 ± 1,748

0.07

APACHEII score at ICU admission

17 ± 3.8

17 ± 3.6

17 ± 4.5

0.9

APACHEIII score at ICU admission

63 ± 14

60 ± 13

68 ± 16

0.1

Postoperative plasma level of ascorbic acid (µg/mL) (n = 34)

19.1 ± 8.1

17.3 ± 5.6

22.1 ± 10.7

0.09

Postoperative cerebral infarction (n)

0.01

Fluid balance in first 48 h in ICU (mL)

1,361 ± 1,915

1,063 ± 1,720

1,957 ± 2,192

0.13

The use of dexmedetomidine before the development of POD (n)

0.6

Intubation time (h)

13 (7.9 - 22.7)

11 (7.5 - 16.6)

23 (8.6 - 89.5)

0.03

Length of ICU stay (h)

94 (88 - 163)

93 (91 - 117)

165 (82 - 222)

0.03

Incidence of POD

33%

Duration of POD (h)

19.9 (11.3 - 59.5)