A new criteria for acute on preexisting kidney dysfunction in critically ill patients

Figures & data

Table 1. Patient demographics and clinical characteristics.

Characteristics	Overall	No PKD	PKD	AKI stages according to KDIGO
				Stage 1	Stage 2	Stage 3
Number of patients	32794	22999	9795	3269	376	2463
Admission age (median, IQR), years	68.0 [56.5, 78.6]	65.0 [53.8, 75.3]	75.2 [64.5, 84.0]	77.1 [67.1, 85.0]	78.8 [68.7, 86.0]	67.8 [56.4, 77.2]
Male (%)	18907 (57.7)	13493 (58.7)	5414 (55.3)	1838 (56.2)	169 (44.9)	1528 (62.0)
Baseline SCr (median, IQR), mg/dL	0.9 [0.6, 1.2]	0.7 [0.6, 0.9]	1.6 [1.3, 2.6]	1.5 [1.3, 1.9]	1.3 [1.1, 1.5]	3.5 [2.2, 5.2]
Peak SCr (median, IQR), mg/dL	1.1 [0.8, 1.8]	0.9 [0.8, 1.2]	2.2 [1.6, 3.9]	2.1 [1.8, 2.7]	2.9 [2.5, 3.4]	5.4 [4.3, 7.2]
eGFR (median, IQR), mL/min/1.73 m^2	84.5 [53.3, 103.1]	96.0 [82.0, 109.6]	37.6 [21.6, 49.6]	40.6 [30.8, 50.4]	48.5 [42.6, 54.1]	15.7 [9.8, 28.3]
SAPSII (median, IQR)	36.0 [28.0, 45.0]	33.0 [26.0, 41.0]	43.0 [36.0, 53.0]	44.0 [36.0, 53.0]	49.0 [41.0, 59.0]	49.0 [40.0, 59.0]
Ethnicity (%)
White	21957 (67.0)	15399 (67.0)	6558 (67.0)	2282 (69.8)	244 (64.9)	1406 (57.1)
Black	2957 (9.0)	1941 (8.4)	1016 (10.4)	274 (8.4)	28 (7.4)	378 (15.3)
Other	7880 (24.0)	5659 (24.6)	2221 (22.7)	713 (21.8)	104 (27.7)	679 (27.6)
Comorbidity
Myocardial infarct (%)	6243 (19.0)	3618 (15.7)	2625 (26.8)	929 (28.4)	112 (29.8)	639 (25.9)
Congestive heart failure (%)	9675 (29.5)	4841 (21.0)	4834 (49.4)	1733 (53.0)	194 (51.6)	1149 (46.7)
Chronic pulmonary disease (%)	8229 (25.1)	5377 (23.4)	2852 (29.1)	1010 (30.9)	104 (27.7)	666 (27.0)
Liver disease (%)	4213 (12.8)	2654 (11.5)	1559 (15.9)	459 (14.0)	71 (18.9)	645 (26.2)
Diabetes (%)	7803 (23.8)	4940 (21.5)	2863 (29.2)	992 (30.3)	114 (30.3)	719 (29.2)
Renal disease (%)	6738 (20.5)	1168 (5.1)	5570 (56.9)	1884 (57.6)	162 (43.1)	1698 (68.9)
Cancer tumor (%)	5028 (15.3)	3595 (15.6)	1433 (14.6)	478 (14.6)	71 (18.9)	332 (13.5)
Sepsis (%)	14432 (44.0)	11844 (51.5)	2588 (26.4)	882 (27.0)	133 (35.4)	377 (15.3)
Hypertension (%)	18664 (56.9)	12263 (53.3)	6401 (65.3)	2198 (67.2)	279 (74.2)	1848 (75.0)
Vasopressors use (%)	13302 (40.6)	9047 (39.3)	4255 (43.4)	1476 (45.2)	212 (56.4)	1269 (51.5)
RRT (%)	2012 (6.1)	303 (1.3)	1709 (17.4)	0 (0.0)	0 (0.0)	1475 (59.9)
In hospital mortality (%)	4093 (12.5)	2109 (9.2)	1984 (20.3)	685 (21.0)	142 (37.8)	745 (30.2)

AKI: acute kidney injury; PKD: preexisting kidney dysfunction (baseline eGFR < 60 mL/min/1.73 m²); SCr: serum creatinine; SAPSII: simplified acute physiology score ii; RRT: renal replacement therapy.

Figure 1. Association of the ratio of pSCr/bSCr and the absolute increase in SCr (pSCr-bSCr) with in-hospital mortality in patients with PKD. PKD: preexisting kidney dysfunction. pSCr: peak serum creatinine; bSCr: baseline serum creatinine.

Table 2. Comparison of the incidence and outcomes of AKI defined by different criteria among patients with PKD.

Definition	NOAKI (n%)	AKI (n%)	p Value	NOAKI (mortality, n (%))	AKI (mortality, n (%))	p Value
MIMIC-IV
KDIGO	3687 (37.6)	6108 (62.4)	<0.001	412 (11.2)	1572 (25.7)	<0.001
cROCK	5262 (53.7)	4533 (46.3)	<0.001	711 (13.5)	1273 (28.1)	<0.001
APKD	2124 (21.7)	7671 (78.3)	<0.001	213 (10.0)	1771 (23.1)	<0.001
MIMIC-III
KDIGO	2916 (37.9)	4774 (62.1)	<0.001	417 (14.3)	1217 (25.5)	<0.001
cROCK	4053 (52.7)	3637 (47.3)	<0.001	687 (17.0)	947 (26.0)	<0.001
APKD	1375 (17.9)	6315 (88.1)		176 (12.8)	1458 (23.1)
eICU
KDIGO	9257 (39.1)	14411 (60.9)	<0.001	1187 (12.8)	3471 (24.1)	<0.001
cROCK	13608 (57.5)	10060 (42.5)	<0.001	2050 (15.1)	2608 (25.9)	<0.001
APKD	5361 (26.7)	18307 (77.3)	<0.001	646 (12.1)	4012 (21.9)	<0.001
Definition	NOAKI APKD (mortality, n (%))	AKI missed (mortality, n (%))	p Value	NOAKI APKD	AKI missed HR (95% CI)	p Value
MIMIC-IV
KDIGO	213 (10.0)	199 (12.7)	0.010	Reference	1.31 ( 1.07 − 1.61 )	0.010
cROCK	213 (10.0)	498 (15.9)	<0.001	Reference	1.69 ( 1.43 − 2.01 )	<0.001
MIMIC-III
KDIGO	176 (12.8)	241 (15.6)	0.029	Reference	1.26 ( 1.02 − 1.56 )	0.029
cROCK	176 (12.8)	511 (19.1)	<0.001	Reference	1.61 ( 1.34 − 1.94 )	<0.001
eICU
KDIGO	646 (12.0)	541 (13.9)	0.009	Reference	1.18 ( 1.04 − 1.33 )	0.009
cROCK	646 (12.0)	1404 (17.0)	<0.001	Reference	1.50 ( 1.36 − 1.66 )	<0.001

AKI: acute kidney injury; PKD: preexisting kidney dysfunction (baseline eGFR < 60 mL/min/1.73 m²); SCr: serum creatinine; APKD: acute on preexisting kidney dysfunction.

Table 3. Performance of in-hospital mortality predictive models between APKD and KDIGO in different databases.

Definition	OR	95% CI of OR	AUC	p Value difference in AUC	Sensitivity, %	95% CI for Sensitivity, %	p Value difference in sensitivity
MIMIC-IV
APKD	2.40	2.05 − 2.81	0.730	Reference	0.669	0.649 − 0.690	Reference
KDIGO	2.43	2.15 − 2.75	0.731	0.868	0.638	0.616 − 0.659	<0.001
MIMIC-III
APKD	1.91	1.61 − 2.28	0.686	Reference	0.665	0.642–0.688	Reference
KDIGO	1.87	1.64 − 2.13	0.689	0.354	0.594	0.569–0.618	<0.001
eICU
APKD	1.96	1.79 − 2.15	0.697	Reference	0.670	0.656 − 0.683	Reference
KDIGO	2.16	1.93 − 2.24	0.696	0.885	0.629	0.615 − 0.643	<0.001

AKI: acute kidney injury; PKD: preexisting kidney dysfunction (baseline eGFR < 60 mL/min/1.73 m²); SCr: serum creatinine; APKD: acute on preexisting kidney dysfunction; OR: odd ratio; AUC: area under curve; CI: confidence interval.

Figure 2. The crude and Logistic regression analyses of in-hospital mortality by APKD AKI severity stage in patients with PKD. AKI: acute kidney injury; PKD: preexisting kidney dysfunction (baseline eGFR < 60 mL/min/1.73 m²).

Data availability statement

Source data for information presented in this study are available from the corresponding authors on reasonable request.