Epidemiology of Postoperative Acute Kidney Injury in Hungarian Intensive Care Units: An Exploratory Analysis

Figures & data

Table 1. Baseline characteristics of patients.

	All patients	AKI	non-AKI	p-Value
Patient number, n	265	48	217
Age (year), median (IQR)	63 (52, 71)	67 (58, 77)	61 (50, 70)	0.002
SAPS II score, median (IQR)	21 (12, 34)	40 (29, 57)	18 (12, 28)	<0.001
SOFA score, median (IQR)	2 (1, 5)	5 (3, 9)	2 (1, 4)	<0.001
Serum creatinine at ICU admission (μmol/L), median (IQR)	72 (57, 89)	110 (78, 156)	67 (56, 84)	<0.001
Serum-creatinine peak concentration (μmol/L), median (IQR)	74 (59, 96)	148 (111, 225)	67 (57, 85)	<0.001
Mechanical ventilation, n (%)	68 (25.7)	29 (60.4)	39 (18)	0.002
Vasopressor treatment, n (%)	38 (14.3)	24 (50)	14 (6.5)	<0.001
Number of septic patient, n (%)	27 (10.1)	22 (45.8)	5 (2.3)	<0.001

Note: AKI, acute kidney injury; IQR, interquartile range; SAPS II, Simplified Acute Physiology Score version II; SOFA, Sepsis-related Organ Failure Assessment Score.

Table 2. Mortality and lengths of stay.

Parameters	AKI	non-AKI	p-Value
ICUs stay (days) median (IQR)	6 (3, 17)	2 (2, 3)	<0.001
In-hospital stay (days) median (IQR)	18 (12, 24)	10 (8, 14)	<0.001
ICUs mortality, n (%)	16 (33.3)	15 (63.9)	<0.001
Overall hospital mortality, n (%)	18 (39.6)	19 (8.8)	<0.001

Note: ICU, intensive care unit; IQR, interquartile range.

Table 3. Incidence and outcome of AKI according to the type of surgery.

	Intracranial surgery		Thoracic surgery		Abdominal surgery		Surgery outside the cavities
Variables	AKI	Non-AKI	AKI	Non-AKI	AKI	Non-AKI	AKI	Non-AKI
Patient number, n (%)	5 (12.9)	34 (87.1)	1 (2.0)	50 (98.0)	39 (26.9)	106 (73.1)	3 (10.0)	27 (90.0)
Mechanical ventilation, n (%)	2 (40.0)	23 (67.6)	0	2 (4.0)	25 (64.1)	13 (12.3)	2 (66.6)	1 (3.7)
					p < 0.001		p = 0.009
Vasopressor need, n (%)	2 (40.0)	5 (14. 7)	0	2 (4.0)	21 (53.9)	7 (6.6)	1 (33.3)	0
					p < 0.001		p = 0.008
Septic patients, n (%)	0	0	0	0	20 (51.3)	4 (3.8)	2 (66.6)	1 (3.7)
					p < 0.001		p = 0.009
ICU stay (days), median (IQR)	4 (3, 13)	2 (2, 4)	7 (5, 9)	2 (2, 2)	3 (7, 18)	2 (2, 3)	6 (4, 12)	2 (2, 2)
					p < 0.001
In-hospital stay (days), median (IQR)	19 (4, 24)	12 (6, 16)	11 (10, 12)	10 (8, 11)	18 (13, 24)	11 (9, 14)	18 (16, 29)	7 (5, 14)
					p < 0.001
ICUs mortality, n (%)	3 (60.0)	10 (29.4)	0	0	12 (30.7)	4 (3.8)	1 (33.3)	1 (3.7)
					p < 0.001
Overall hospital mortality, n (%)	3 (60.0)	13 (38.2)	0	0	15 (38.5)	5 (4.7)	1 (33.3)	1 (3.7)
					p < 0.001

Note: AKI, acute kidney injury; ICU, intensive care unit; IQR, interquartile range.

Table 4. Distribution of AKI according to the types of abdominal procedures and diagnoses.

Abdominal procedures	All patients	Non-AKI	AKI Stage 1	AKI Stage 2	AKI Stage 3	AKI all.	p-Value
Gastric and small bowel, n (%)	35 (24.1)	25 (71.4)	5 (14.3)	2 (5.7)	3 (8.6)	10 (28.6)	Non-AKI vs. AKI all p = 0.7899
Colorectal, n (%)	61 (42.1)	44 (72.1)	10 (16.4)	3 (4.9)	4 (6.6)	17 (27.9)
Pancreas, liver and biliary (n) (%)	40 (27.6)	32 (80.0)	4 (10.0)	2 (5.0)	2 (5.0)	8 (20.0)
Other, n (%)	9 (6.2)	5 (55.6)	1 (11.1)	3 (33.3)	0	4 (44.4)
All, n (%)	145 (100)	106 (73.1)	20 (13.8)	10 (6.9)	9 (6.2)	39 (26.9)
Diagnoses
Mechanical obstruction, n (%)	13 (9.0)	5 (38.5)	2 (15.4)	3 (23.1)	3 (23.1)	8 (61.5)	Non-AKI vs. AKI all p = 0.0043
Perforation, n (%)	17 (11.7)	8 (47.1)	3 (17.7)	3 (17.7)	3 (17.7)	9 (52.9)
Inflammation/abscess, n (%)	23 (15.9)	17 (73.9)	4 (17.4)	2 (8.7)	1 (4.4)	7 (30.4)
Cancer, n (%)	77 (53.1)	65 (84.4)	8 (10.4)	4 (5.2)	0	12 (15.6)	Cancer vs. mechanical obstruction p = 0.0035
Other, n (%)	15 (10.3)	11 (73.3)	2 (13.3)	1 (6.7)	1 (6.7)	4 (26.7)	Cancer vs. perforation p = 0.0107

Note: AKI, acute kidney injury.

Table 5. Logistic regression analysis to evaluate the influencing factors of AKI development and ICU mortality.

							95% CI
	Variables	Coefficient	SE	Wald test	p-Value	OR	Lower	Upper
	Age	0.047	0.017	7.961	0.005	1.048	1.014	1.082
AKI development	Serum creatinine at ICU admission	0.035	0.007	24.589	<0.001	1.035	1.021	1.047
	Sepsis	2.379	0.721	10.889	0.001	10.791	9.353	12.233
	Vasopressor treatment	2.277	0.586	16.065	<0.001	9.751	8.579	10.923
	Neurosurgery	1.968	0.576	12.036	0.001	7.157	6.005	8.309
	Age	0.039	0.019	4.316	0.038	1.040	1.002	1.078
ICU mortality	Vasopressor treatment	0.010	0.003	10.065	0.002	1.010	1.004	1.016
	SAPS II score	0.047	0.012	14.994	<0.001	1.048	1.024	1.072
	Serum creatinine peak concentration	0.007	0.002	8.034	0.005	1.007	1.003	1.011

Note: AKI, acute kidney injury; CI, confidence interval; ICU, intensive care unit; OD, odds ratio; SE, standard error.