Early acute kidney injury after liver transplantation: Predisposing factors and clinical implications

Table 1 Patient demographics

Variables	No AKI (n = 58)	Any grade of AKI (n = 58)	P value
Patient characteristics
Age (yr)	54 (18)	56 (6)	0.197
Female	17 (29%)	16 (28%)	0.837
Weight (kg)	75 (13)	79 (15)	0.163
Aetiology
Alcohol	13	14
Viral hepatitis	20	25
NASH	2	7
Autoimmune	16	7
Hepatocellular carcinoma	10	13
Other	7	6
MELD score	16 (7)	16 (5.75)	0.421
Hypertension	8 (14%)	9 (16%)	0.733
Diabetes mellitus	12 (21%)	20 (34%)	0.074
Pre-operative Haemoglobin (g/L)	114 (20)	107 (26)	0.072
Baseline creatinine	76 (39)	75 (26)	0.932

Values expressed as mean (SD), median (interquartile range) and number (percentage) where appropriate. AKI: Acute kidney injury; NASH: Non-alcoholic steato-hepatitis; MELD: Model for End-Stage Liver Disease.

Table 2 Donor graft characteristics

Variables	No AKI (n = 58)	Any AKI (n = 58)	P value
Graft characteristics
Donor age (yr)	50 (14)	47 (15)	0.219
Organ status
DCD (%)	7 (12%)	10 (17%)	0.454
Cold Ischaemic time (min)	493 (133)	493 (106)	0.502

Values expressed as mean (SD), median (interquartile range) and number (percent) where appropriate. DCD: Donation after cardiac death; AKI: Acute kidney injury.

Table 3 Intraoperative variables

Variable	No AKI (n = 58)	Any AKI (n = 58)	P value
Intraoperative variables
Surgical technique
Piggyback	33 (57%)	22 (38%)	0.041
Intraoperative blood products
RCC transfusion (units)	1 (3)	4 (5)	0.001
FFP transfusion (units)	0 (2)	2 (6)	0.001
Platelet transfusion (units)	0 (1)	0 (2)	0.024
Cell salvage (mL)	281 (550)	764 (929)	0.001
Noradrenaline infusion rate on arrival to ICU (μg/kg per minute)	0.16 (0.10)	0.18 (0.13)	0.343

Values expressed as mean (SD), median (interquartile range) and number (percent) where appropriate. AKI: Acute kidney injury; RCC: Red cell concentrate; FFP: Fresh frozen plasma; ICU: Intensive care unit.

Table 4 Logistic regression analysis of variables associated with early acute kidney injury after liver transplantation

	Univariate analysis		Multivariate model
Variables	Odds ratio (95%CI)	P value	Odds ratio (95%CI)	P value
Male gender	1.088 (0.49-2.44)	0.837	0.430 (0.07-2.55)	0.352
Weight	1.020 (0.99-1.05)	0.164	1.026 (0.96-1.10)	0.455
Age	1.034 (0.999-1.07)	0.058	1.121 (1.02-1.23)	0.019
Pre-transplant
Diabetes mellitus	2.130 (0.92-4.92)	0.077	2.429 (0.48-12.41)	0.286
Hypertension	1.197 (0.43-3.36)	0.733	0.593 (0.04-8.04)	0.694
Serum creatinine	1.000 (0.99-1.01)	0.937	0.979 (0.96-1.002)	0.078
MELD	1.010 (0.97-1.05)	0.639	0.992 (0.91-1.08)	0.845
Haemoglobin	0.985 (0.97-1.002)	0.076	0.977 (0.93-1.02)	0.311
Graft characteristics
DCD organ	1.488 (0.52-4.23)	0.455	2.638 (0.30-23.12)	0.381
Donor age	0.984 (0.96-1.01)	0.218	0.964 (0.92-1.01)	0.160
Cold ischaemic time	1.001 (0.99-1.004)	0.498	1.000 (0.99-1.01)	0.984
Peak serum AST < 24 h post OLT	1.001 (1.00-1.001)	0.001	1.001 (1.00-1.001)	0.020
Perioperative course
Caval replacement surgical technique	2.160 (1.03-4.54)	0.042	3.289 (0.71-15-25)	0.128
Noradrenaline infusion rate on ICU arrival	4.830 (0.19-125.48)	0.343	47.468 (0.12-1836.27)	0.204
RCC transfusion	1.137 (1.03-1.26)	0.014	0.917 (0.64-1.32)	0.645
FFP transfusion	1.201 (1.07-1.35)	0.003	1.118 (0.84-1.48)	0.440
Platelet transfusion	1.499 (1.04-2.16)	0.030	1.948 (0.871-4.36)	0.104
Cell salvage volume	1.001 (1.00-1.001)	0.025	1.00 (0.999-1.002)	0.808

CI: Confidence interval; MELD: Model for End-Stage Liver Disease; DCD: Donation after Cardiac death; ICU: Intensive care unit; RCC: Red cell concentrate; FFP: Fresh frozen plasma; AST: Aspartate aminotransferase; OLT; Orthotopic liver transplantation.

Table 5 The effect of organ status and surgical technique on hepatic ischaemia reperfusion injury severity and the renal implications of increasing ischaemia reperfusion injury n (%)

	Severity of HIRI
	Mild (n = 35)	Moderate (n = 68)	Severe (n = 13)	P value
DCD organs	1/35 (2.9)	11/68 (16.2)	5/13 (38.5)	0.007
Caval replacement	16/35 (45.7)	36/68 (52.9)	9/13 (69.2)	0.348
Incidence of AKI	12/35 (34.3)	34/68 (50.0)	12/13 (92.3)	0.002
Need for CVVHF	5/35 (14.3)	15/68 (22.1)	8/13 (61.5)	0.003
Development of CRF	6/30 (20.0)	19/53 (35.8)	5/11 (45.5)	0.195

HIRI: Hepatic ischaemia reperfusion injury; DCD: Donation after Cardiac death; AKI: Acute kidney injury; CVVHF: Continuous veno-venous haemofiltration; CRF: Chronic renal failure.