Table 2.

Urinary NGAL levels at various time points preoperatively and postoperatively, comparing patients who developed AKI with those who did not

	Urine NGAL, ng/ml,		P
	No AKI	AKI-Positive
eGFR 0 to 30 ml/min (n = 21)
n	12	9
Preoperative	20 (11 to 379)	32 (10 to 76)	0.91
Immediately after CPB	300 (146 to 1349)	295 (87 to 933)	0.62
3 h after CPB	339 (15 to 904)	329 (112 to 1638)	0.68
18 h after CPB	788 (96 to 3120)	260 (98 to 2607)	0.63
24 h after CPB	1380 (151 to 5144)	755 (152 to 813)	0.37
eGFR 30 to 60 ml/min (n = 101)
n	81	20
Preoperative	10 (3 to 44)	7 (3 to 83)	0.96
Immediately after CPB	731 (39 to 1951)	630 (130 to 2216)	0.64
3 h after CPB	463 (16 to 1385)	407 (59 to 1546)	0.64
18 h after CPB	44 (14 to 800)	88 (32 to 608)	0.48
24 h after CPB	80 (21 to 958)	291 (28 to 642)	0.92
eGFR 60 to 90 ml/min (n = 142)
n	107	35
Preoperative	7 (3 to 21)	8 (3 to 26)	0.96
Immediately after CPB	549 (7 to 1993)	1740 (157 to 4399)	0.01
3 h after CPB	106 (4 to 830)	1335 (14 to 2714)	0.001
18 h after CPB	37 (11 to 195)	53 (23 to 483)	0.13
24 h after CPB	44 (14 to 318)	46 (25 to 464)	0.40
eGFR 90 to 120 ml/min (n = 109)
n	96	13
Preoperative	5 (2 to 10)	22 (6 to 38)	0.03
Immediately after CPB	43 (5 to 1472)	1354 (34 to 2674)	0.06
3 h after CPB	17 (3 to 405)	256 (29 to 3003)	0.049
18 h after CPB	15 (7 to 40)	148 (39 to 313)	0.002
24 h after CPB	18 (10 to 33)	283 (72 to 866)	0.0001
eGFR >120 ml/min (n = 53)
n	45	8
Preoperative	5 (2 to 12)	5 (2 to 9)	0.82
Immediately after CPB	1047 (18 to 2795)	3 (0 to 1922)	0.01
3 h after CPB	88 (12 to 2195)	1 (1 to 6)	0.03
18 h after CPB	17 (6 to 55)	9 (3 to 16)	0.08
24 h after CPB	19 (8 to 99)	8 (4 to 15)	0.05

Values are given as median, with interquartile range in parentheses. Comparisons are stratified by baseline renal function determined by eGFR (calculated by Cockroft-Gault equation). Comparisons are made using Mann-Whitney U test.