Cumulative positive fluid balance is a risk factor for acute kidney injury and requirement for renal replacement therapy after liver transplantation

Table 1 Baseline characteristics before liver transplantation (n = 121)

Male sex	106 (88%)
Age (yr)	50 ± 13
Etiology of chronic liver disease
Hepatitis C	39 (32%)
Hepatitis C and alcoholic liver disease	12 (10%)
Alcoholic liver disease	36 (30%)
Cryptogenic and/or non-alcoholic steatohepatitis	10 (8%)
Hepatitis B	4 (3%)
Cholestatic liver disease	6 (5%)
Autoimmune hepatitis	4 (3%)
Others	10 (8%)
Indication for liver transplantation
Decompensated cirrhosis	93 (77%)
Hepatocellular carcinoma	28 (23%)
Severity of liver disease at admission
Child-Pugh score	9 ± 2
MELD score	18 ± 6

Data are expressed as mean ± SD. MELD: Model for end-stage liver disease.

Table 2 Intraoperative and postoperative features of the patients submitted to liver transplantation (n = 121)

Cold ischemia time (min)	520 ± 170
Duration of surgery (min)	333 ± 104
Use of blood products	77 (63%)
Number of packed red blood cell units	1.9 ± 3.1
Use of vasoactive drugs (norepinephrine)	38 (31%)
Peak of arterial lactate in the first 24 h (mmol/L)	2.3 ± 2.0
APACHE II score 24 h after admission	15 ± 4
Peak of AST levels (U/L)	3058 ± 4820
Peak of ALT levels (U/L)	1357 ± 1542
Postoperative complications
Early allograft dysfunction	26 (22%)
Primary graft non-function	7 (6%)
Biliary strictures and/or leaks	5 (4%)
Arterial thrombosis or stenosis	5 (4%)
Acute rejection	32 (26%)
Sepsis or septic shock	38 (31%)
AKI	87 (72%)
AKI type 1	0
AKI type 2	44 (36%)
AKI type 3	43 (36%)
RRT	26 (22%)
Fluid balance (mL)
Intraoperative	3829 ± 1904
Cumulative FB in the first 12 h	5473 ± 2417
Cumulative FB in the first 4 d	10956 ± 5117
Length of stay in ICU (d)	12 ± 11
Length of stay in the hospital (d)	19 ± 12
Mortality	11 (9%)

Data are expressed as mean ± SD. APACHE II: Acute Physiology and Chronic Health Disease Classification System; AKI: Acute kidney injury; RRT: Renal replacement therapy; FB: Fluid balance; ICU: Intensive care unit.

Table 3 Comparison of baseline, intra-operative and postoperative features of patients submitted to liver transplantation according to the presence of acute kidney injury

	No AKI (n = 34)	AKI (n = 87)	P value
Age (yr)	51 ± 13	50 ± 12	0.643
Male sex	24 (71%)	82 (94%)	0.0001
Child-Pugh score at admission	8 ± 2	10 ± 2	0.840
MELD score at admission	17 ± 6	18 ± 6	0.868
APACHE II score 24 h after admission	14 ± 3	15 ± 4	0.142
Cold ischemia time (min)	537 ± 187	513 ± 164	0.267
Duration of surgery (min)	324 ± 131	336 ± 92	0.439
Use of blood products	59%	66%	0.490
Number of packed red blood cell units	1.0 ± 1.7	2.2 ± 3.4	0.010
Use of vasoactive drugs	6 (18%)	32 (37%)	0.032
Peak of arterial lactate in the first 24 h (mmol/L)	2.2 ± 1.4	2.4 ± 2.2	0.208
Peak AST levels (U/L)	1789 ± 1524	3535 ± 5511	0.022
Postoperative complications
Early allograft dysfunction	3 (4%)	24 (28%)	0.019
Biliary strictures and/or leaks	1 (3%)	4 (5%)	0.567
Arterial thrombosis or stenosis	2 (6%)	3 (3%)	0.433
Acute rejection	10 (29%)	22 (25%)	0.402
Sepsis or septic shock	8 (24%)	30 (34%)	0.305
Cumulative FB in the first 12 h	4780 ± 1673	5743 ± 2610	0.050
Cumulative FB in the first 4 d	8690 ± 3463	11841 ± 5395	0.050
Length of stay in ICU (d)	8 ± 8	13 ± 11	0.087
Length of stay in the hospital (d)	15 ± 7	20 ± 12	0.001
Mortality	1 (3%)	10 (12%)	0.128

Data are expressed as mean ± SD. AKI: Acute kidney injury; MELD: Model for end-stage liver disease; APACHE II: Acute Physiology and Chronic Health Disease Classification System; FB: Fluid balance; ICU: Intensive care unit.

Table 4 Comparison of baseline, intra-operative and postoperative features of patients submitted to liver transplantation according to requirement of renal replacement therapy

	No RRT (n = 95)	RRT (n = 26)	P value
Age (yr)	49 ± 12	53 ± 12	0.960
Male sex	80 (84%)	26 (100%)	0.0001
Child-Pugh score at admission	9 ± 2	10 ± 2	0.800
MELD score at admission	18 ± 6	19 ± 7	0.420
APACHE II 24 h after admission	14 ± 4	18 ± 6	0.030
Cold ischemia time (min)	506 ± 166	587 ± 175	0.470
Duration of surgery (min)	322 ± 103	372 ± 102	0.500
Use of blood products	59%	81%	0.030
Number of packed red blood cell units	1.6 ± 2.7	2.7 ± 4.2	0.080
Use of vasoactive drugs	25 (26%)	13 (50%)	0.020
Peak of arterial lactate in the first 24 h (mmol/L)	2.1 ± 1.3	3.3 ± 3.5	0.0001
Peak AST levels (U/L)	2144 ± 2157	6599 ± 9060	0.0001
Postoperative complications
Early allograft dysfunction	14 (15%)	13 (50%)	0.0001
Biliary strictures and/or leaks	3 (3%)	2 (8%)	0.292
Arterial thrombosis or stenosis	5 (5%)	0 (0)	0.290
Acute rejection	27 (28%)	5 (19%)	0.249
Sepsis or septic shock	23 (24%)	15 (58%)	0.0001
Cumulative FB in the first 12 h	5014 ± 2181	7146 ± 2538	0.005
Cumulative FB in the first 4 d	9868 ± 3677	14924 ± 7345	0.0001
Length of stay in ICU (d)	9 ± 9	20 ± 14	0.002
Length of stay in the hospital (d)	17 ± 10	24 ± 14	0.007
Mortality	2 (2%)	9 (35%)	0.0001

Data are expressed as mean ± SD. RRT: Renal replacement therapy; MELD: Model for end-stage liver disease; APACHE II: Acute Physiology and Chronic Health Disease Classification System; FB: Fluid balance; ICU: Intensive care unit.

Table 5 Comparison of baseline, intra-operative and postoperative features of patients submitted to liver transplantation according to mortality in 28 d

	Survivors (n = 110)	Non survivors (n = 11)	P value
Age (yr)	50 ± 12	52 ± 13	0.780
Male sex	95 (86%)	11 (100%)	0.218
Child-Pugh score at admission	9 ± 2	10 ± 3	0.360
MELD score at admission	18 ± 6	19 ± 9	0.060
APACHE II 24 h after admission	14 ± 3	21 ± 6	0.060
Cold ischemia time (min)	512 ± 167	628 ± 177	0.080
Duration of surgery (min)	324 ± 98	417 ± 130	0.060
Use of blood products	64%	64%	0.620
Number of packed red blood cell units	1.7 ± 2.6	3.6 ± 6	0.000
Use of vasoactive drugs	32(29%)	6 (55%)	0.090
Peak of arterial lactate in the first 24 h (mmol/L)	2.1 ± 1.4	4.9 ± 4.2	0.0001
Peak AST levels (U/L)	2372 ± 2280	11289 ± 13591	0.0001
Postoperative complications
Early allograft dysfunction	19 (17%)	8 (72%)	0.0001
Biliary strictures and/or leaks	5 (5%)	0	0.620
Arterial thrombosis or stenosis	5 (5%)	0	0.620
Acute rejection	32 (29%)	0	0.030
Sepsis or septic shock	34 (31%)	4 (36%)	0.740
Cumulative FB in the first 12 h	5205 ± 2233	8140 ± 2677	0.600
Cumulative FB in the first 4 d	10144 ± 3656	19073 ± 9416	0.00001
Length of stay in ICU (d)	12 ± 10	14 ± 11	0.360
Length of stay in the hospital (d)	18 ± 11	13 ± 10	0.070
AKI	77 (70%)	10 (90%)	0.140
RRT	17 (15%)	9 (82%)	0.0001

Data are expressed as mean ± SD. LT: Liver transplantation; MELD: Model for end-stage liver disease; APACHE II: Acute Physiology and Chronic Health Disease Classification System; FB: Fluid balance; ICU: Intensive care unit; AKI: Acute kidney injury; RRT: Renal replacement therapy.

Table 6 Multivariate analysis of predictors of acute kidney injury, renal replacement therapy and mortality of patients submitted to liver transplantation

	Odds ratio	95%CI	P value
AKI
Male sex	9.29	1.48-58.24	0.017
Cumulative FB in the first 4 d	2.3	1.37-3.86	0.020
RRT
APACHE II 24 h after admission	2.5	1.36-4.62	0.003
Sepsis or septic shock	14.7	0.99-2.18	0.050
Cumulative FB in the first 4 d	2.89	1.52-5.49	0.001
Mortality
AST levels (U/L)	2.35	1.1-5.05	0.020
APACHE II 24 h after admission	2.63	1.0-6.87	0.040

AKI: Acute kidney injury; RRT: Renal replacement therapy; APACHE II: Acute Physiology and Chronic Health Disease Classification System; FB: Fluid balance.