Characteristics and risk factors for renal recovery after acute kidney injury in critically ill patients in cohorts of elderly and non-elderly: a multicenter retrospective cohort study

Figures & data

Figure 1. Flow chart of selected patients.

Table 1. Comparison of demographic and clinical characteristics for the study population.

	Age < 63-year cohort			Age ≥ 63-year cohort
	Renal recovery n = 198	No renal recovery n = 85	p Value	Renal recovery n = 86	Non renal recovery n = 214	p Value
Age (years, M[P25–P75])	51.0 (44.0, 56.0)	52.0 (46.0, 55.0)	0.853	69.0 (66.3, 77.0)	70.0 (66.0, 77.0)	0.894
Male sex (n[%])	116 (58.6)	56 (65.9)	0.249	63 (73.3)	146 (68.2)	0.391
Past medical history [n (%)]
Hypertension	28 (14.1)	20 (23.5)	0.054	20 (23.3)	90 (42.1)	0.002
Diabetes mellitus	19 (9.6)	10 (11.8)	0.581	14 (16.3)	74 (34.6)	0.002
Coronary heart disease	20 (10.1)	13 (15.3)	0.212	29 (33.7)	68 (31.8)	0.745
Chronic kidney disease	37 (18.7)	9 (10.6)	0.087	15 (17.4)	47 (22.0)	0.370
Cause of AKI (n[%])
Sepsis	38 (19.2)	25 (29.4)	0.058	15 (17.4)	65 (30.4)	0.022
Hypovolemia	98 (49.5)	34 (40.0)	0.142	46 (53.5)	84 (39.3)	0.024
Heart failure	39 (19.7)	12 (14.1)	0.263	17 (19.8)	49 (22.9)	0.554
Nephrotoxic drugs	12 (6.1)	4 (4.7)	0.651	6 (7.0)	15 (7.0)	0.992
Retrorenal obstruction	11 (5.6)	10 (11.8)	0.402	2 (2.3)	1 (0.5)
Vasopressor drugs (n[%])	47 (23.7)	26 (30.6)	0.227	23 (26.7)	97 (45.3)	0.011
Surgery under general anesthesia (n[%])	49 (24.7)	34 (40.0)	0.010	19 (22.1)	82 (38.3)	0.007
AKI stage (n[%])
1	82 (41.4)	13 (15.3)	<0.001	59 (68.6)	47 (22.0)	<0.001
2	77 (38.9)	25 (29.4)		21 (244)	67 (31.3)
3	39 (19.7)	47 (55.3)		6 (7.0)	100 (46.7)
APACHE II score (M[P25–P75])	14.0 (12.0, 18.0)	16.0 (12.0, 20.5)	0.003	17.5 (15.0, 19.0)	18.0 (17.0, 21.0)	0.016
Laboratory data
PO2/FiO2 ratio (M[P25–P75])	254.0 (189.0, 315.3)	230.0 (199.7, 281.8)	0.174	220.0 (172.9, 247.0)	198.0 (165.8, 245.0)	0.171
Lactate (mmol/L, M[P25–P75])	1.8 (1.3, 2.3)	2.3 (1.2, 3.4)	0.023	2.4 (1.8, 3.1)	2.7 (1.9, 3.6)	0.077
Hemoglobin (g/L, M[P25–P75])	108.0 (89.0, 123.0)	83.0 (77.0, 100.0)	<0.001	97.0 (86.0, 107.8)	77.0 (68.0, 97.0)	<0.001
Albumin (g/L, M[P25–P75])	28.6 (25.7, 32.6)	27.6 (26.0, 29.8)	0.068	27.4 (25.2, 31.0)	26.0 (24.0, 28.4)	0.015
eGFR(mL/min/1.73 m^2, M[P25–P75])	39.2 (24.7, 51.0)	32.9 (22.9, 50.6)	0.222	38.4 (29.8, 51.1)	27.2 (21.5, 35.5)	<0.001
D-Dimer (ng/L, M[P25–P75])	1420.0 (495.3, 3230.5)	2360.0 (925.0, 3935.0)	0.025	1248.5 (657.8.0, 2560.0)	1970.0 (961.0, 3945.0)	0.002
C-reactive protein (mg/L, M[P25–P75])	96.8 (45.9, 177.9)	174.9 (66.7, 187.9)	0.006	59.6 (23.6, 120.5)	112.6 (44.6, 182.1)	<0.001

AKI: acute kidney injury; APACHE II: acute physiologic assessment and chronic health evaluation II; eGFR: estimated glomerular filtration rate.

Figure 2. The ROC curve of risk factors for the prediction of the nonrenal recovery (A) and renal recovery (B) of AKI in the age < 63 years cohort, and the risk factors for the prediction of the nonrenal recovery (C) and renal recovery (D) of AKI in the age ≥ 63 year cohort.

Table 2. Multivariate logistic regression analysis for nonrenal recovery in AKI cohorts of different ages.

	Age < 63 year cohort		Age ≥ 63 year cohort
	OR (95% CI)	p value	OR (95% CI)	p Value
AKI stage	2.54 (1.72–3.73)	<0.001	3.50 (2.20–5.56)	<0.001
Hemoglobin (g/L)	0.97 (0.96–0.98)	<0.001	0.98 (0.96–0.99)	0.003
Lactate (mmol/L)	1.32 (1.09–1.59)	0.004
Diabetes mellitus			2.85 (1.29–6.33)	0.010
eGFR (mL/min/1.73 m^2)			0.95 (0.93–0.97)	<0.001
Surgery under general anesthesia			2.72 (1.24–5.96)	0.012
APACHE II score			1.15 (1.03–1.28)	0.012

AKI: acute kidney injury; eGFR: estimated glomerular filtration rate; APACHE II: acute physiologic assessment and chronic health evaluation II.

Data availability statement

The datasets used and/or analyzed during the current study available from the corresponding author on reasonable request.