Development and Standardization of a Furosemide Stress Test to Predict the Severity of Acute Kidney Injury

Table 1 Patient characteristics

Variable	Combined	Non-progressors	AKIN III	P
	n = 77	n = 52	n = 25
Age, years	65.3 (1.6)	63.8 (2.2)	68.2 (1.9)	0.13
Gender, % male	42.8%	36.5%	56.0%	0.14
Race, n (%)
African American	44 (57.1%)	29 (55.6%)	15 (60.0%)	0.63
Caucasian	23 (29.9%)	15 (28.8%)	8 (32.0%)	0.92
Hispanic	10 (13.0%)	8 (15.4%)	2 (8.0%)	0.48
Comorbidities, n (%)
CKD	24 (31.0%)	17 (32.7%)	7 (28.0%)	0.80
Hypertension	60 (78.0%)	41 (78.8%)	19 (76.0%)	0.78
CHF	25 (33.0%)	15 (29.0%)	10 (40.0%)	0.44
DM	35 (44.0%)	22 (41.5%)	13 (52.0%)	0.47
Nephrotoxic exposure, n (%)
NSAIDS	8 (10.0)%	6 (2.0%)	2 (1.0%)	1.00
Aminoglycosides	1 (1.0%)	0 (0.0%)	1 (0.4%)	0.63
Amphotericin	2 (3.0%)	2 (4.0%)	0 (0.0%)	1.00
Contrast	21 (27.0%)	15 (28.8%)	6 (23.1%)	0.79
Post-cardiac surgery	9 (11.7%)	6 (11.5%)	3 (12.0%)	1.00
Sepsis	15 (19.5%)	12 (23.1%)	3 (12.0%)	0.36
Clinical Data
Baseline eGFR, ml/minute/1.73m²	68.6 (4.1)	60.0 (8.8)	73.3 (4.2)	0.15
Baseline UFR (ml/hr)	74.6 (11.6)	95.7 (16.3)	29.7 (4.2)	0.001
Furosemide-naïve, n (%)	29 (37.7%)	23 (44.2%)	6 (24.0%)	0.13
Urine cast score)	2.3 (0.13)	2.1 (0.16)	2.7 (0.23)	0.05
FeNa above 1%, n (%)^a	14 (18.0%)	10 (19.2%)	4 (16.0%)	1.00
CV SOFA score	1.16 (0.3)	1.05 (0.2)	1.5 (0.4)	0.37
APACHE II score	17.8 (1.11)	16.5 (1.2)	21.6 (2.5)	0.08
AKIN stage at enrollment, n (%)
AKIN I	41 (53.2%)	34 (65.4%)	7 (28.0%)	0.003
AKIN II	36 (46.7%)	18 (34.6%)	18 (72.0%)	0.003
Outcomes, n (%)
Death	16 (20.7%)	7 (13.4%)	9 (36.0%)	0.04
AKIN stage III	25 (32.4%)	N/A	25 (100%)	N/A
RRT	11 (14.2%)	N/A	11 (44.0%)	N/A
Death/AKIN III	32 (41.5%)	7 (13.4%)	25 (100.0%)	0.001

Data are presented as mean ± standard error unless otherwise indicated. CKD, chronic kidney disease; CHF, congestive heart failure; DM, diabetes mellitus; NSAIDs, non-steroidal anti-inflammatory drugs; eGFR, estimated glomerular filtration rate; UFR, urinary flow rate; CV SOFA, Cardiovascular Sequential Organ Failure Assessment; APACHE, Acute Physiology and Chronic Health Evaluation; AKIN, Acute Kidney Injury Network; FeNa, fractional excretion of sodium; RRT, renal replacement therapy; RPP, renal perfusion pressure; n, number of patients; N/A, not applicable. ^aFeNa not assessed in 29 patients because the George Washington University Urine Sediment Score was already ≥2 at the time of assessment.