Retrospective analysis on incidence and risk factors of early onset acute kidney injury after lung transplantation and its association with mortality

Figures & data

Figure 1. Incidence of AKI per day between day 1 and day 7 after lung transplantation.

Table 1. Baseline demographic characteristics of LTx patients by AKI status.

Parameters	No-AKI	AKI	p Value^a	AKI stage
				1	2	3	p Value^b
n (%)	26 (19.1)	110 (80.9)		38 (27.9)	32 (23.5)	40 (29.4)
Age	61 (54–66)	60 (54–64)	.496	61 (52–64)	62 (57–64)	59 (49–65)	.711
Male, n (%)	23 (88.5)	94 (85.5)	.934	31 (81.6)	26 (81.3)	37 (92.5)	.417
BMI, kg/m^2	20.9 (3.9)	21.5(4.0)	.520	21.1(4.4)	22.1 (4.2)	21.4 (3.6)	.678
BSA, m^2	1.8 (0.2)	1.8 (0.2)	.362	1.8 (0.2)	1.8 (0.2)	1.8 (0.2)	.556
Diagnosis, n (%)			.314				.392
COPD	7 (26.9)	16 (14.5)		3 (7.9)	4 (12.5)	9 (22.5)
ILD	18 (69.2)	79 (71.8)		28 (73.7)	24 (75.0)	27 (67.5)
PH	0 (0)	10 (9.1)		5 (13.2)	3 (9.4)	2 (5.0)
CF	0 (0)	1 (0.9)		1 (2.6)	0 (0)	0 (0)
Others	1 (3.8)	4 (3.6)		1 (2.6)	1 (3.1)	2 (5.0)
Comorbidities, n (%)
Hypertension	4 (15.4)	24 (21.8)	.466	6 (15.8)	5 (15.6)	13 (32.5)	.178
Diabetes mellitus	10 (38.5)	33 (30.0)	.404	13 (34.2)	12 (37.5)	8 (20.0)	.297
Hyperlipidemia	1 (3.8)	9 (8.2)	.731	1 (2.6)	4 (12.5)	4 (10.0)	.366
Smoking history, n (%)	22 (84.6)	80 (72.7)	.208	26 (68.4)	23 (71.9)	31 (77.5)	.483
SCr, μmol/L	60.2 (16.0)	54.5 (14.3)	.076	56.6 (15.8)	53.4 (11.9)	53.3 (14.6)	.227
eGFR, mL/min/1.73 m^2	124 (33)	140 (41)	.056	134 (39)	137 (28)	149 (50)	.073
ALT, IU/L	20 (12–27)	18 (14–32)	.883	17 (11–24)	20 (15–34)	17 (14–35)	.329
AST, IU/L	20 (15–23)	20 (16–23)	.833	19 (15–23)	20 (18–40)	18 (16–22)	.098
RBC, ×10^12 cells/L	7.0 (5.9–8.4)	6.7 (5.3–9.0)	.532	6.2 (5.0–8.9)	7.1 (6.0–9.1)	6.3 (5.2–8.8)	.317
Hemoglobin, g/L	131 (17)	137 (22)	.197	134 (21)	138 (20)	137 (25)	.524
Hematocrit, %	39.6 (5.1)	41.2 (6.6)	.267	40.9 (6.0)	41.1 (5.5)	41.5 (7.9)	.695
Glucose, mmol/L	4.2 (0.7)	4.5 (0.8)	.099	4.5 (0.7)	4.5 (0.7)	4.6 (0.9)	.358

LTx: lung transplantation; AKI: acute kidney injury; BMI: body mass index; BSA: body surface area; COPD: chronic obstructive disease; ILD: interstitial lung disease; PH: pulmonary hypertension; CF: cystic fibrosis; SCr: serum creatinine; eGFR: estimated glomerular filtration rate; ALT: alanine aminotransferase; AST: aspartate aminotransferase; RBC: red blood cells.

Categorical data are presented as number (%) (n (%)), continuous data presented as mean with standard deviation (mean (SD)) or median with inter-quartile range (med (IQR)), depending on variable distribution.

^a p value compared between no-AKI and AKI.

^b p value compared between different AKI stages and no-AKI.

Table 2. Intra-operative and post-operative parameters of LTx patients by AKI status.

				AKI stage
Parameters	No-AKI	AKI	p Value^a	1	2	3	p Value^b
Transplant type, n (%)			.481				.208
Unilateral	18 (69.2)	68 (61.8)		25 (65.8)	23 (71.9)	20 (50.0)
Bilateral	8 (30.8)	42 (38.2)		13 (34.2)	9 (28.1)	20 (50.0)
Operation duration, min	225 (180–285)	255 (198–330)	.248	238 (210–338)	240 (180–330)	270 (180–334)	.670
Intra-operative ECMO support, n (%)	16 (61.5)	75 (68.2)	.517	29 (76.3)	21 (65.6)	25 (62.5)	.526
Loss of blood, mL	300 (100–500)	300 (200–500)	.368	300 (200–550)	300 (150–400)	300 (200–575)	.546
Basiliximab use, n (%)	10 (38.5)	45 (40.9)	.819	15 (39.5)	11 (34.4)	19 (47.5)	.712
Post-operative ECMO support, n (%)	15 (57.7)	76 (69.1)	.267	29 (76.3)	21 (65.6)	26 (65.0)	.456
Median TAC concentration, ng/mL	5.0 (2.4–7.8)	7.6 (4.7–11.0)	.011	5.9 (3.7–8.8)	7.9 (4.9–10.9)	9.0 (6.5–13.9)	.001
Nephrotoxic drugs ≥ 6, n (%)	6 (23.0)	38 (34.5)	.261	9 (23.7)	10 (31.3)	19 (47.5)	.088

LTx: lung transplantation; AKI: acute kidney injury; ECMO: extracorporeal membrane oxygenation; TAC: tacrolimus.

Categorical data are presented as number (%) (n (%)), continuous data presented as mean with standard deviation (mean (SD)) or median with inter-quartile range (med (IQR)), depending on variable distribution.

^a p value compared between no-AKI and AKI.

^b p value compared between different AKI stages and no-AKI.

Table 3. Multivariate analysis for risk factors of AKI.

Covariate	Univariate		Multivariate
	OR (95% CI)	p Value	OR (95% CI)	p Value
SCr, μmol/L	0.98 (0.95–1.00)	.080
eGFR, mL/min/1.73 m^2	1.01 (1.00–1.03)	.056	1.01 (1.00–1.03)	.049
Hemoglobin, g/L	1.01 (0.99–1.04)	.196
Glucose, mmol/L	1.67 (0.91–3.07)	.099
Median TAC concentration, ng/mL	1.14 (1.02–1.29)	.024	1.15 (1.02–1.30)	.022

CI: confidence interval; AKI: acute kidney injury; SCr: serum creatinine; eGFR: estimated glomerular filtration rate; TAC: tacrolimus.

p Value for the Hosmer–Lemeshow goodness-of-fit test was .601.

Table 4. Post-operative outcomes by AKI status.

				AKI stage
Parameters	No-AKI	AKI	p Value^a	1	2	3	p Value^b
IMV days, d	1 (1–2)	2 (1–3)	.015	2 (1–2)	2 (1–2)	2 (2–8)	.002
ICU stay, d	3 (2–4)	4 (3–6)	.011	4 (3–5)	4 (3–5)	6 (3–10)	.009
Hospital stay, d	42 (34–56)	45 (30–63)	.605	42 (32–56)	46 (29–92)	46 (24–72)	.812

AKI: acute kidney injury; IMV: invasive mechanical ventilation; ICU: intensive care unit.

Data presented as median with inter-quartile range (med (IQR)), depending on variable distribution.

^a p value compared between no-AKI and AKI.

^b p value compared between different AKI stages and no-AKI.

Figure 2. Kaplan–Meier’s survival curves stratified by AKI stages and no-AKI at (A) 30-day and (B) 1-year.