Incidence, Predictive Factors, and Clinical Outcomes of Acute Kidney Injury after Gastric Surgery for Gastric Cancer
and Clinical Outcomes of Acute Kidney Injury after Gastric Surgery
for Gastric Cancer. PLoS ONE 8(12): e82289. doi:10.1371/journal.pone.0082289
Incidence, Predictive Factors, and Clinical Outcomes of Acute Kidney Injury after Gastric Surgery for Gastric Cancer
Chang Seong Kim 0
Chan Young Oak 0
Ha Yeon Kim 0
Yong Un Kang 0
Joon Seok Choi 0
Eun Hui Bae 0
Seong Kwon Ma 0
Sun-Seog Kweon 0
Soo Wan Kim 0
Ariela Benigni, IRCSS - Istituto di Ricerche Farmacologiche Mario Negri, Italy
0 1 Department of Internal Medicine, Chonnam National University Medical School , Gwangju , Korea , 2 Department of Preventive Medicine, Chonnam National University Medical School , Gwangju , Korea , 3 Jeonnam Regional Cancer Center, Chonnam National University Hwasun Hospital , Hwasun-gun , Republic of Korea
Background: Postoperative acute kidney injury (AKI), a serious surgical complication, is common after cardiac surgery; however, reports on AKI after noncardiac surgery are limited. We sought to determine the incidence and predictive factors of AKI after gastric surgery for gastric cancer and its effects on the clinical outcomes. Methods: We conducted a retrospective study of 4718 patients with normal renal function who underwent partial or total gastrectomy for gastric cancer between June 2002 and December 2011. Postoperative AKI was defined by serum creatinine change, as per the Kidney Disease Improving Global Outcomes guideline. Results: Of the 4718 patients, 679 (14.4%) developed AKI. Length of hospital stay, intensive care unit admission rates, and in-hospital mortality rate (3.5% versus 0.2%) were significantly higher in patients with AKI than in those without. AKI was also associated with requirement of renal replacement therapy. Multivariate analysis revealed that male gender; hypertension; chronic obstructive pulmonary disease; hypoalbuminemia (,4 g/dl); use of diuretics, vasopressors, and contrast agents; and packed red blood cell transfusion were independent predictors for AKI after gastric surgery. Postoperative AKI and vasopressor use entailed a high risk of 3-month mortality after multiple adjustments. Conclusions: AKI was common after gastric surgery for gastric cancer and associated with adverse outcomes. We identified several factors associated with postoperative AKI; recognition of these predictive factors may help reduce the incidence of AKI after gastric surgery. Furthermore, postoperative AKI in patients with gastric cancer is an important risk factor for shortterm mortality.
Funding: This research was supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of
Education, Science and Technology (2011-0009743), and by the National Research Foundation of Korea (NRF) grant (MRC for Gene Regulation, 2011-0030132)
funded by the Korea government (MSIP). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the
Competing Interests: The authors have declared that no competing interests exist.
Although the incidence of gastric cancer has been declining in
most advanced nations over the past 2 decades, it remains a major
cause of morbidity and mortality worldwide as well as one of the
most common malignancies in many east Asian countries [1,2]. In
patients with gastric cancer, perioperative chemotherapy as well as
postoperative chemotherapy combined with radiation therapy
reduces the recurrence rate and prolongs survival, but surgical
resection of the primary tumor and its draining lymph nodes offers
the only chance for cure [3,4]. Various complications (such as
pneumonia, wound infection, deep vein thrombosis, and impaired
renal function) occur in patients with gastric cancer after gastric
surgery [5,6,7]. However, the risk factors for postoperative acute
kidney injury (AKI) and its effects on the clinical outcomes are not
well understood in patients with gastric cancer.
AKI is a serious morbidity occurring during hospitalizations,
and it is associated with prolonged hospital stay, high risk of
inhospital mortality and increased hospital costs . In addition,
AKI increases the risk of incident and progressive chronic kidney
disease and is associated with reduced long-term survival . AKI
has been reported to occur in 57% of hospitalized patients, but it
accounts for up to 20% of admissions in intensive care units
(ICUs). Among cases of AKI occurring during hospitalization,
approximately 2540% cases are observed in the operative setting
[10,11,12]. Although the incidence of postoperative AKI varies
with the specific surgical setting, most studies have been performed
on postoperative AKI patients undergoing cardiac or vascular
surgery. Data on AKI developing in non-cardiovascular surgical
settings are limited [13,14,15].
We hypothesized that comorbid conditions and perioperative
treatments influence the risk for postoperative AKI in gastric
cancer patients undergoing gastric surgery. This retrospective
study evaluated the incidence and predictive factors of AKI after
gastric surgery for gastric cancer, as well as the association
between postoperative AKI and clinical outcomes, including
mortality and hospital length of stay.
Materials and Methods
Study design and patient population
We reviewed the electronic medical records and laboratory
results of all adult patients who underwent total or subtotal
gastrectomy for gastric cancer in Chonnam National University
Hospital between June 1, 2002 and December 31, 2011. Among
the 5,160 patients identified, those with insufficient data,
emergency operation, chronic kidney disease [preoperative
estimated glomerular filtration rate (GFR) ,60 mL/
(min?1.73 m2)] or end-stage renal disease (patients with a history
of hemodialysis, peritoneal dialysis, or kidney transplantation)
were excluded. We also excluded patients who died within
24 hours of gastric surgery because their mortality was not
associated with renal dysfunction and the data were inappropriate
for the evaluation of postoperative renal dysfunction. Finally, data
from 4,718 patients were analyzed in this study. Cases of death
were ascertained by data linkage to the national death certificate
database of Statistics Korea and the regional cancer registries.
This study was conducted in accordance with the Declaration of
Helsinki guidelines. The study protocol was approved by the
Institutional Review Board of Chonnam National University
Hwasun Hospital in 2013, and informed consent was waived by
the Institutional Review Board.
Data collection and definition
The demographic and perioperative variables assessed were
age; sex; heart rate; body mass index; and previous history of
hypertension, diabetes mellitus, and chronic obstructive
pulmonary disease (COPD). Laboratory data on levels of serum
creatinine (SCr), hemoglobin (Hgb), and albumin were extracted
from the medical records. The postoperative variables evaluated
were use of diuretics, non-steroidal anti-inflammatory drugs
(NSAIDs), packed red blood cell (RBC) transfusion, contrast
agent, and vasopressors.
AKI was defined according to the Kidney Disease Improving
Global Outcomes (KDIGO) clinical practice guidelines. According
to these criteria, AKI is present when an abrupt reduction in
kidney function results in an absolute increase in SCr level by
$0.3 mg/dL within 48 hours, an increase of 1.5-fold or more in
the baseline SCr level known or presumed to have occurred within
prior 7 days, or a reduction in urine output (,0.5 mL/(kg?h) for
6 hours) . We did not consider the urine output criteria
because retrospectively collected data have the potential to be
inaccurate in this regard. AKI is further classified into 3 stages
according to the severity of kidney injury: AKI stage 1, increase in
SCr by $0.3 mg/dL or 1.51.9 times baseline; AKI stage 2,
increase in SCr of 2.02.9 times baseline; and AKI stage 3,
increase in SCr to $4.0 mg/dL or $3.0 times baseline or
initiation of renal replacement therapy. Anemia was defined by the
World Health Organization (WHO) diagnostic criteria (Hgb level
of ,13.0 g/dl and ,12.0 g/dl in men and women, respectively)
. Preoperative hypoalbuminemia was defined as serum
albumin levels of ,4.0 g/dL . Smoking was defined as
current or ex-smoker. Hypertension was defined by a systolic
blood pressure of .140 mmHg, a diastolic blood pressure of
.90 mmHg or self-reported hypertension, irrespective of
antihypertensive medications. Diabetes mellitus was defined by the
need for insulin or glucose-lowering medication to control glucose
levels on admission, or medical history of diet-controlled diabetes.
Intraoperative hypotension was defined by the entry of a systolic
blood pressure of ,90 mmHg or use of vasopressors (including
dopamine, norepinephrine, epinephrine and vasopressin) in the
intraoperative anesthesia records.
Assessment of renal function
SCr levels were analyzed by the Jaffe method, which was
calibrated to isotope dilution mass spectrometry. Estimated GFR
was calculated with the Chronic Kidney Disease Epidemiology
Collaboration (CKD-EPI) equation as follows: mL/(min?1.73
m2) = 1416minimum (creatinine/k, 1)a6maximum (creatinine/k,
1)21.20960.993age61.018 (if female)61.159 (if black), where k is
0.7 for women and 0.9 for men and a is 20.329 for women and
20.411 for men .
Continuous variables are expressed as mean 6 standard
deviation or as medians with interquartile (25th and 75th
percentiles) ranges for parametric and nonparametric variables,
and categorical variables are presented as the number of patients
and percentage. Comparative analysis was performed using
Students t-test, analysis of variance, or Kruskal-Wallis test for
continuous variables, as appropriate, and Pearson chi-square test
for categorical variables. Univariate and multivariate logistic
regression analyses were performed to identify the independent
predictors of postoperative AKI after gastric surgery. Age, sex and
variables with a P of ,0.1 on univariate analysis were entered into
the multivariate logistic regression models. The variables included
in the analyses were age; sex; history of hypertension and COPD;
smoking; anemia; hypoalbuminemia; use of diuretics, vasopressors,
packed RBC transfusion, and contrast agent, intraoperative
hypotension; and operation time. An analysis of covariance and
multiple logistic regressions adjusted to age and sex was performed
to evaluate the association between postoperative AKI and clinical
outcomes. We also used logistic regression analyses with backward
selection to identify whether postoperative AKI was associated
with 3-month mortality after gastric surgery in patients with gastric
cancer. All statistical tests were two-tailed, and P ,0.05 was
considered significant. The analyses were performed using the
Statistical Package for Social Sciences software, version 17.0
(SPSS, Chicago, Illinois).
Risk of Acute Kidney Injury
A total 4,718 patients were included in the final analysis. The
mean age of the patients was 63.2 years. Of the enrolled patients,
679 patients (14.4%) developed AKI during the postoperative
period. Fourteen (2.1%) of the 679 patients developed severe AKI
that required renal replacement therapy. According to the
KDIGO guideline, 589 of 679 (86.7%) patients were found to
have stage 1 AKI; 61 (9.0%) patients, stage 2 AKI; and 29 (4.3%)
patients, stage 3 AKI (Figure 1).
The baseline characteristics of patients according to the
presence or severity of AKI are listed in Table 1. Patients
developing AKI were older and had a higher prevalence of
hypertension, COPD, and smoking. They were more likely to
have anemia and hypoalbuminemia than patients without AKI.
However, there was no difference between the 2 groups in the
body mass index and the prevalence of diabetes mellitus.
Postoperative use of diuretics, contrast agent, and transfusion of
packed RBC were higher in patients with AKI than in those
without AKI. Furthermore, the prevalence of anemia and
hypoalbuminemia; intraoperative hypotension; use of diuretics,
contrast agents, and vasopressin; and transfusion of packed RBCs
tended to be higher in patients with higher AKI stage.
Table 2 shows the results of multivariate analysis of predictive
factors for AKI after gastric surgery. Multivariate logistic analysis
revealed that male gender; hypertension; COPD;
hypoalbuminemia; and use of diuretics, vasopressors, packed RBC transfusion,
and contrast agents were independently associated with the
development of AKI.
As shown in Table 3, the in-hospital and 3-month mortality for
patients with AKI were significantly higher than those for patients
without AKI (3.5% versus 0.2%, P,0.001; 3.8% versus 0.3%,
P,0.001, respectively). Figure 2 shows the mortality rate
according to the AKI stage. The rate of in-hospital and 3-month
mortality increased with the advancement in the stage of AKI, in a
stepwise manner. In addition, patients with AKI had significantly
longer hospital stay and higher prevalence of ICU admission after
the operation (mean 18.7 days versus 12.0 days, P,0.001; 9.1%
versus 1.2%, P,0.001, respectively). However, there were no
significant differences between the patients with and without AKI
in the length of ICU stay.
We sought to determine whether postoperative AKI was
associated with 3-month mortality after gastric surgery in gastric
cancer patients by using multivariate logistic regression analysis.
The development of postoperative AKI was significantly
associated with 3-month mortality after multiple adjustments (OR, 8.75;
95% CI, 3.9819.27; P,0.001), along with age, male gender and
use of vasopressors. Low-grade AKI (stage 1), which constituted
the majority of postoperative AKI cases in our study, was also an
independent predictor for 3-month mortality after gastric cancer
surgery (OR, 3.88; 95% CI, 1.4710.25; P = 0.006). Moreover, the
relative risks for 3-month mortality increased exponentially as the
AKI stage increased (Table 4).
In this study, we determined the incidence, predictive factors,
and outcomes for AKI, defined according to the recently
published and validated KDIGO guidelines, occurring after
gastric surgery in patients with gastric cancer. We found that
14.4% of these patients developed postoperative AKI and that
2.1% of these patients required renal replacement therapy. Male
gender, hypertension, COPD, hypoalbuminemia, and use of
diuretics, vasopressors, packed RBC transfusion and contrast
agents were identified as independent predictors for postoperative
AKI. Furthermore, in-hospital and 3-month mortality increased
with the severity of AKI, and patients developing AKI had a
higher risk of 3-month mortality after gastric surgery.
Postoperative AKI remains a leading cause of morbidity,
mortality, prolonged hospital stay, and increased hospital cost
[10,20]. The reported incidence of postoperative AKI varies from
0.8% to 30%, depending on the definition of AKI, the
preoperative renal function of the patients, and the various
surgery types considered in the respective studies [15,21,22].
Although data available on the incidence of AKI after noncardiac
surgery are lesser than those available on AKI after cardiovascular
surgery, the incidence of postoperative AKI in our study was
comparable to that noted in previous studies [13,14]. One study
revealed that an incidence of 8.5% for AKI, defined as either a
50% increase in SCr level or requirement of dialysis, developing
after gastric bypass surgery for morbid obesity . Another study
reported an incidence of 30% for AKI in patients undergoing liver
transplantation and indicated that the frequency of severe AKI
requiring dialysis can be as high as 17% . However, a recent
study  showed a relatively low incidence of postoperative AKI
(less than 1%) in patients with normal kidney function undergoing
noncardiac surgery. In that study, AKI was defined by an absolute
level of estimated GFR (,50 mL/min) within the first 7
postoperative days, which is a highly restrictive criterion for the
detection of AKI. Consequently, the underestimation of the
incidence of postoperative AKI in the abovementioned study
compared to ours may be attributed to the difference in the
definitions of AKI in both the studies. Unfortunately, as
mentioned earlier, there is no uniformity in the definition of
AKI adopted in the various studies. Recently, KDIGO proposed
new criteria wherein AKI is defined by alterations in the SCr level
within 7 days. Therefore, the KDIGO criteria can detect AKI in
patients with slow increase in creatinine and may also be a better
predictor of mortality and represent a standardized, simple
method of categorizing AKI . We thought that the new
KDIGO criteria were useful for the precise diagnosis of
Our findings demonstrated that hypertension, COPD and
hypoalbuminemia were independent preoperative predictors for
AKI after gastric surgery. Kheterpal et al . have reported
preoperative AKI risk factors such as old age, emergency surgery,
liver disease, high body mass index, high-risk surgery, peripheral
vascular disease, and COPD, but they did not evaluate the
preoperative status of laboratory parameters, including albumin
and Hgb, under non-cardiovascular surgical settings. Indeed,
hypoalbuminemia has been shown to be an important risk factor
for AKI in various clinical conditions [14,24,25,26]. Another study
on patients who underwent off-pump coronary bypass surgery
revealed that a low preoperative serum albumin level (,4.0 g/dL)
is independently associated with postoperative AKI, as observed in
our study . Although the underlying mechanisms by which
hypoalbuminemia causes the development of postoperative AKI
are not completely understood, albumin appears to not only
improve renal perfusion through prolonged potent renal
vasodilatation but also inhibits the apoptosis of renal tubular cells
through its capacity to scavenge reactive oxygen species [27,28].
Consequently, albumin plays a crucial role in the maintenance of
proximal tubular integrity and function. Therefore, low level of
serum albumin may contribute to an increased risk of
postoperative AKI in patients undergoing gastric surgery.
ItsaegK 6..86121 .()7241 63313 6150 6166 6..8232 .()1810 .()3208 .)(66 .()5431 6..6224 .()4150 ..,.()31644 .()3621 6..092 6..73140 6..095 6..2214 .()3191 .()5547 .)(66 .()1604 .()1927 .()7035 .)(61 .()4902 .()4589 .()2662 itcaeedm
A 6 4 1 8 7 2 1 2 4 3 1 2 4 2 0 9 1 4 1 3 4 1 1 4 1 3 2 1 iv
eg ) .9 ) ) ) 2 ) .)5 ) .9 3 ) ) ) ) ) )
Itsa =589 6.111 .(3769 6014 610 615 6..337 .()136 .(6350 .()75 .(2547 6..12 .(7351 .,(394 .(4262 6.902 6.012 6.03 6.21 .(5232 .(6537 .(2173 .()158 .()105 .(3650 .()22 .(5229 .(3311 .()61 feo
K 4 5 3 3 3 3 0 0 4 2 3 0 .3 5 . 8 .3 .2 3 1 0 3 2 8 3 3 8 6 iv
A (n 6 4 1 8 7 2 8 2 4 3 1 2 4 1 0 9 1 4 1 3 1 9 6 3 1 1 1 3 t
u 1 1 1 1 1 1 1 1 1
lav .400 .000 .430 .393 .190 .025 .836 .020 .000 .130 .000 .000 .000 .000 .137 .000 .000 .100 .070 .000
P 0 , 0 0 0 0 0 0 , 0 , , , , 0 , , 0 0 ,
Age (per 10 years)
Intraoperative hypotension e 1.02
Operation time (per hour)
aDefined by a systolic blood pressure of .140 mmHg, a diastolic blood
pressure of .90 mmHg or self-reported hypertension irrespective of
bHemoglobin ,13.0 g/dL in men, hemoglobin ,2.0 g/dL in women.
cAlbumin ,4.0 g/dL.
dNorepinephrine, epinephrine, dopamine, vasopressin, or phenylephrine
infusions on postoperative day 1 or 2.
eDefined by a systolic blood pressure of ,90 mmHg or use of vasopressors in
the intraoperative anesthesia records.
Abbreviations: CI, confidence interval; COPD, chronic obstructive pulmonary
disease; p-RBC, packed red blood cell.
Several intraoperative management variables were found to be
independent predictors of AKI. Use of vasopressors and diuretics
is associated with increased postoperative AKI, as reported in a
previous study . Although it is unclear whether use of diuretics
is a cause or a consequence of postoperative AKI, indiscriminate
use of diuretics to treat postoperative low urine output should be
avoided, especially in patients with hypovolemic status.
Interestingly, transfusion of packed RBCs may also have deleterious effects
No AKI (n = 4039) AKI (n = 679) P value a
In-hospital death (%)
RRT or CRRT (%)
ICU length of stay (days)
3 months death (%)
Hospital length of stay(days) 12.067.1
aP value by age and sex-adjusted analysis of covariance (ANCOVA) or logistic
regression as appropriate.
Abbreviations: AKI, acute kidney injury; RRT, renal replacement therapy; CRRT,
continuous renal replacement therapy; ICU, intensive care unit.
on renal outcomes, because the shortened lifespan of the preserved
RBC results in circulating free iron-mediated nephrotoxicity with
hemolysis and free Hgb, as well as induction of oxidative stress
[29,30]. Those are important mechanisms of AKI. We also found
that packed RBC transfusion was associated with postoperative
AKI in the multivariate analysis, as reported in previous studies
[31,32]. This finding suggests that unnecessary blood transfusions
should be avoided in patients undergoing gastric surgery.
However, anemia and intraoperative hypotension were not
associated with AKI in this study, which is in contrast to the
results previously reported [31,33]. A potential reason for this
discrepancy might be attributed to the relatively higher level of
mean Hgb (13.3 mg/dL) in our study than in the previous one
. In other words, severe anemia, particularly in combination
with intraoperative hypotension might contribute to renal injury,
thereby highlighting a potential synergic effect. Indeed, arterial
hypoxemia or hypotension alone would not lead to renal injury,
possibly because of the compensating effect of increased renal
blood flow or decreased renal oxygen consumption 
AKI without supporting renal replacement therapy is associated
with increased mortality in critically ill patients and in patients
who have undergone surgery [10,11,15]. Our findings also showed
Age (per 10 years)
Abbreviations: AKI, acute kidney injury.
aConditional logistic regression adjusted by age, gender, hypertension, COPD,
smoking, diabetes mellitus, anemia, hypoalbuminemia, the use of diuretics,
vasopressors, and RBC transfusion, intraoperative hypotension, gastric cancer
stage, and AKI stage.
that in-hospital and 3-month mortality, and prevalence of ICU
care in patients with AKI were higher than those in patients
without AKI, and the values of these factors increased in a
stepwise manner with the severity of the injury defined as per the
KDIGO criteria. It appears that more severe AKI is associated
with a higher risk for morbidity and mortality in patients
undergoing gastric surgery. Although the 3-month mortality
recorded in this study was lower than reported previously for
noncardiac surgeries of different types , it should be noted that
in both studies, the patients who developed AKI had significantly
high mortality rates. Furthermore, our results revealed that
patients with postoperative AKI had an 8.75-fold higher risk of
3-month mortality compared to those without AKI. Postoperative
AKI has never been tested as a predictor of mortality after gastric
surgery in gastric cancer patients, as in our study; thus, our study
provides valuable, independent information. In addition, the
duration of hospitalization, which has been recognized as a
surrogate indicator of costs, was significantly greater in
postoperative AKI patients compared with those without AKI after gastric
surgery. Thus, AKI can be viewed as a distinct therapeutic target,
the prevention and treatment of which may improve the clinical
outcomes of surgery.
The strengths of this study are the relatively large number of
patients, use of recent and validated AKI definitions for the
assessment of clinical outcomes, and inclusion of various
perioperative predictors. Our study also has several limitations.
First, we used only the change in the SCr level to determine the
occurrence of AKI because exact data regarding urine output were
not available for this retrospective study. This may have resulted in
underestimation of the incidence of AKI. Second, despite our best
efforts to adjust our results for most confounders, the results of this
study may have been affected by residual confounding.
AKI was common after gastric surgery for gastric cancer, and
several factors were associated with the development of
postoperative AKI. Postoperative AKI in patients with gastric cancer is a
potent predictive factor for adverse clinical outcomes after gastric
surgery. Therefore, identifying predictive factors and preventing
the development of postoperative AKI are essential for improving
Conceived and designed the experiments: CSK JSC SWK. Performed the
experiments: CSK SSK. Analyzed the data: CSK EHB SKM SSK SWK.
Contributed reagents/materials/analysis tools: CSK CYO HYK YUK
SSK. Wrote the paper: CSK SKM SSK SWK.
14. Cabezuelo JB , Ramirez P , Rios A , Acosta F , Torres D , et al. ( 2006 ) Risk factors of acute renal failure after liver transplantation . Kidney Int 69 : 1073 - 1080 .
15. Kheterpal S , Tremper KK , Englesbe MJ , O'Reilly M , Shanks AM , et al. ( 2007 ) Predictors of postoperative acute renal failure after noncardiac surgery in patients with previously normal renal function . Anesthesiology 107 : 892 - 902 .
16. Kellum JA , Lameire N ( 2013 ) Diagnosis, evaluation, and management of acute kidney injury: a KDIGO summary (Part 1) . Crit Care 17 : 204 .
17. ( 1968 ) Nutritional anaemias . Report of a WHO scientific group . World Health Organ Tech Rep Ser 405 : 5 - 37 .
18. Lee EH , Baek SH , Chin JH , Choi DK , Son HJ , et al. ( 2012 ) Preoperative hypoalbuminemia is a major risk factor for acute kidney injury following offpump coronary artery bypass surgery . Intensive Care Med 38 : 1478 - 1486 .
19. Levey AS , Stevens LA , Schmid CH , Zhang YL , Castro AF 3rd , et al. ( 2009 ) A new equation to estimate glomerular filtration rate . Ann Intern Med 150 : 604 - 612 .
20. Abelha FJ , Botelho M , Fernandes V , Barros H ( 2009 ) Determinants of postoperative acute kidney injury . Crit Care 13 : R79 .
21. Reddy VG ( 2002 ) Prevention of postoperative acute renal failure . J Postgrad Med 48 : 64 - 70 .
22. Lassnigg A , Schmidlin D , Mouhieddine M , Bachmann LM , Druml W , et al. ( 2004 ) Minimal changes of serum creatinine predict prognosis in patients after cardiothoracic surgery: a prospective cohort study . J Am Soc Nephrol 15 : 1597 - 1605 .
23. Mizuno T , Sato W , Ishikawa K , Shinjo H , Miyagawa Y , et al. ( 2012 ) KDIGO (Kidney Disease: Improving Global Outcomes) criteria could be a useful outcome predictor of cisplatin-induced acute kidney injury . Oncology 82 : 354 - 359 .
24. Rich MW , Keller AJ , Schechtman KB , Marshall WG , Jr., Kouchoukos NT ( 1989 ) Increased complications and prolonged hospital stay in elderly cardiac surgical patients with low serum albumin . Am J Cardiol 63 : 714 - 718 .
25. Engelman DT , Adams DH , Byrne JG , Aranki SF , Collins JJ Jr, et al. ( 1999 ) Impact of body mass index and albumin on morbidity and mortality after cardiac surgery . J Thorac Cardiovasc Surg 118 : 866 - 873 .
26. de la Cruz KI , Bakaeen FG , Wang XL , Huh J , LeMaire SA , et al. ( 2011 ) Hypoalbuminemia and long-term survival after coronary artery bypass: a propensity score analysis . Ann Thorac Surg 91 : 671 - 675 .
27. Kaufmann MA , Castelli I , Pargger H , Drop LJ ( 1995 ) Nitric oxide dose-response study in the isolated perfused rat kidney after inhibition of endothelium-derived relaxing factor synthesis: the role of serum albumin . J Pharmacol Exp Ther 273 : 855 - 862 .
28. Iglesias J , Abernethy VE , Wang Z , Lieberthal W , Koh JS , et al. ( 1999 ) Albumin is a major serum survival factor for renal tubular cells and macrophages through scavenging of ROS . Am J Physiol 277 : F711 - 722 .
29. de Vries B , Walter SJ , von Bonsdorff L , Wolfs TG , van Heurn LW , et al. ( 2004 ) Reduction of circulating redox-active iron by apotransferrin protects against renal ischemia-reperfusion injury . Transplantation 77 : 669 - 675 .
30. Comporti M , Signorini C , Buonocore G , Ciccoli L ( 2002 ) Iron release, oxidative stress and erythrocyte ageing . Free Radic Biol Med 32 : 568 - 576 .
31. Haase M , Bellomo R , Story D , Letis A , Klemz K , et al. ( 2012 ) Effect of mean arterial pressure, haemoglobin and blood transfusion during cardiopulmonary bypass on post-operative acute kidney injury . Nephrol Dial Transplant 27 : 153 - 160 .
32. Bagur R , Webb JG , Nietlispach F , Dumont E , De Larochelliere R , et al. ( 2010 ) Acute kidney injury following transcatheter aortic valve implantation: predictive factors, prognostic value, and comparison with surgical aortic valve replacement . Eur Heart J 31 : 865 - 874 .
33. Arora P , Rajagopalam S , Ranjan R , Kolli H , Singh M , et al. ( 2008 ) Preoperative use of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers is associated with increased risk for acute kidney injury after cardiovascular surgery . Clin J Am Soc Nephrol 3 : 1266 - 1273 .
34. Flemming B , Seeliger E , Wronski T , Steer K , Arenz N , et al. ( 2000 ) Oxygen and renal hemodynamics in the conscious rat . J Am Soc Nephrol 11 : 18 - 24 .