Prevalence and outcome of acute kidney injury, as defined by the new Kidney Disease Improving Global Outcomes guideline, in very low birth weight infants

Table 3 Patients with or without acute kidney injury, n (%) unless stated otherwise

	No AKI n = 259	Stage 1 AKI n = 6	Stage 2 AKI n = 12	Stage 3 AKI n = 16	Univariate analysis P value	Multivariate analysis4P value
Males	122 (47)	4 (67)	7 (58)	9 (56)	0.61	NS
Birth weight (g): mean (SD)	1130 (267)	976 (271)	791 (257)	850 (253)	< 0.0012	NS
Gestational age (wk): median (range)	29.0 (22-35)	28.0 (23-32)	25.0 (23-30)	25.5 (23-38)	< 0.0013	NS
Mode of delivery					0.031	NS
Vaginal delivery	40 (15)	1 (17)	3 (25)	9 (56)		NS
Cesarean section	219 (84)	5 (83)	9 (75)	7 (43)		NS
Maternal steroids	193 (74)	5 (83)	8 (67)	11 (69)	0.91	NS
Intraventricular hemorrhage					< 0.0011	NS
Grade 1	15 (6)	1 (16)	0 (0)	0 (0)		NS
Grade 2	8 (3)	1 (16)	0 (0)	1 (6)		NS
Grade 3	9 (3)	1 (16)	1 (8)	2 (13)		NS
Grade 4	9 (4)	0 (0)	1 (8)	6 (40)		NS
Necrotizing enterocolitis	16 (6)	1 (16)	6 (50)	7 (43)	< 0.0011	0.001
Patent ductus arteriosus					0.031	NS
Tiny	29 (11)	1 (16)	1 (8)	3 (18)		NS
Moderate	32 (12)	0 (0)	3 (25)	4 (25)		NS
Large	19 (7)	1 (16)	3 (25)	2 (12)		NS
Sepsis					< 0.0011	NS
Clinical sepsis	45 (17)	3 (50)	6 (50)	7 (43)		NS
Sepsis with normotension	22 (8)	1 (16)	0 (0)	1 (6)		NS
Sepsis with hypotension	14 (5)	1 (16)	6 (50)	5 (31)		NS
Duration of mechanical ventilation (d): median (range)	2 (1-160)	3.5 (1-29)	17.5 (7-71)	13 (2-262)	< 0.0013	NS
Surgery required	11 (4)	1 (16)	4 (33)	6 (37)	< 0.0011	NS
Inotrope use	37 (14)	2 (33)	8 (66)	12 (75)	< 0.0011	NS
Ibuprofen use	51 (19)	1 (16)	7 (58)	4 (25)	0.011	NS
Vancomycin use	59 (22)	3 (50)	10 (83)	12 (75)	< 0.0011	NS
Gentamycin use	173 (66)	5 (83)	11 (91)	14 (87)	0.081	NS
Steroids use	24 (9)	1 (16)	6 (50)	7 (43)	< 0.0011	NS
Umbilical arterial catheter use	129 (49)	5 (83)	8 (66)	16 (100)	< 0.0011	NS
Oliguria					< 0.0011	NS
< 0.5 mL/kg per hour for 6 h	0 (0)	0 (0)	1 (8)	2 (12)		NS
< 0.3 mL/kg per hour for 24 h	0 (0)	1 (16)	3 (25)	6 (37)		NS
Hypotension	35 (13)	2 (33)	9 (75)	12 (75)	< 0.0011	NS
Normal saline intravenous bolus	28 (10)	2 (33)	9 (75)	11 (68)	< 0.0011	NS
Furosemide	4 (1)	1 (16)	3 (25)	4 (25)	< 0.0011	NS
Duration of hospital stay in survivors (d): median (range)	52 (15-280)	64.5 (53-125)	74.5 (7-116)	116 (44-362)	0.023	NS
Mortality	27 (10)	2 (33)	8 (66)	9 (56)	< 0.0011	NS
Serum creatinine (µmol/L) on discharge: median (range)	44 (23)	64 (56)	93 (47)	133 (135)	< 0.0013	NS
Mean blood pressure (mmHg) on discharge: median (range)	55 (13)	48 (24)	38 (13)	41 (19)	< 0.0013	NS

¹χ² or Fisher exact test;

²Analysis of variance (ANOVA);

³Kruskal-Wallis test;

⁴Logistic regression. NS: Not significant; AKI: Acute kidney injury.