Comparison of the RIFLE, AKIN, and KDIGO Diagnostic Classifications for Acute Renal Injury in Patients Undergoing Liver Transplantation

Incidence and Risk Factors of Acute Kidney Injury in Pediatric Liver Transplant Patients: A Retrospective Study

Background

Acute kidney injury (AKI) significantly contributes to the mortality and morbidity rates among pediatric liver transplant (LT) recipients.

Objective

Our study aimed to assess the potential factors contributing to AKI in pediatric LT patients and to analyze the impact of AKI on postoperative mortality and hospitalization duration.

Materials and methods

About 235 pediatric LT patients under the age of 18 between the years 2015 and 2021 were evaluated retrospectively. The relationship between preoperative and intraoperative variables of the patients and AKI developed when the early postoperatıve period was assessed.

Results

A correlation was found between the patients' preoperative age, albumin levels, and AKI. AKI was found to be associated with the duration of surgery and intraoperative blood transfusion.

Conclusion

Our findings revealed that the severity of AKI in pediatric LT patients is linked to extended surgical durations and increased blood transfusions resulting from hemodynamically compromised blood loss. Furthermore, independent risk factors for AKI were identified as prolonged warm ischemia and the overall duration of the operation.

How to cite this article

Demiroz D, Colak YZ, Ozdes OO, Ucar M, Ali Erdogan M, Toprak HI, et al. Incidence and Risk Factors of Acute Kidney İnjury in Pediatric Liver Transplant Patients: A Retrospective Study. Indian J Crit Care Med 2024;28(1):75-79.

A Critical Reassessment of the Kidney Risk Caused by Tetrastarch Products in the Perioperative and Intensive Care Environments

Purpose: To reassess the results of former meta-analyses focusing on the relationship between novel HES preparations (130/0.4 and 130/0.42) and acute kidney injury. Previous meta-analyses are based on studies referring to partially or fully unpublished data or data from abstracts only. Methods: The studies included in the former meta-analyses were scrutinized by the authors independently. We completed a critical analysis of the literature, including the strengths, weaknesses and modifiers of the studies when assessing products, formulations and outcomes. Results: Both the published large studies and meta-analyses show significant bias in the context of the deleterious effect of 6% 130/0.4-0.42 HES. Without (1) detailed hemodynamic data, (2) the exclusion of other nephrotoxic events and (3) a properly performed evaluation of the dose-effect relationship, the AKI-inducing property of 6% HES 130/0.4 or 0.42 should not be considered as evidence. The administration of HES is safe and effective if the recommended dose is respected. Conclusions: Our review suggests that there is questionable evidence for the deteriorating renal effect of these products. Further well-designed, randomized and controlled trials are needed. Additionally, conclusions formulated for resource-rich environments should not be extended to more resource-scarce environments without proper qualifiers provided.

Comparing the effect of administering gelatin-low dose albumin versus albumin on renal function in liver transplantation: A randomized clinical trial

BACKGROUND

Acute kidney injury (AKI) is a common complication after liver transplantation (LT) that is independently associated with an increased risk of morbidity and mortality. This study aimed to evaluate the effects of administering gelatin-low dose albumin versus albumin on renal function and other early outcomes in LT.

METHODS

This randomized controlled clinical trial was conducted on 140 patients undergoing LT from brain death donors. Patients were randomly assigned to two groups: albumin or modified gelatin with albumin. Blood samples were collected before (T0) and on the first (T1), second (T2), third (T3), fifth (T4), and last day of hospitalization (T5) after LT for the detection of laboratory parameters, including renal and liver function tests.

RESULTS

The incidence of AKT on the basis of RIFLE criteria was 31.42% in the gelatin group (R: 59.10%, I: 36.40%, and F: 4.50%) and 25.71% in the albumin group (R: 66.70%, I: 27.80%, and F: 5.50%) (p = .845). Two patients in the gelatin and one in the albumin groups required renal replacement therapy (RRT). There was no significant difference between groups when the trends of changes in renal and liver function parameters were assessed during the study period (T0-T5). Furthermore, the incidence of complications was similar across groups.

CONCLUSION

This study showed that modified gelatin could be used without inappropriate outcomes on renal function in patients with normal preoperative kidney function tests undergoing LT.

Risk factors for acute kidney injury after liver transplantation in intensive care unit: a retrospective cohort study

BACKGROUND

Acute kidney injury (AKI) is a frequent complication during the postoperative period following liver transplantation. Occurrence of AKI in intensive care unit (ICU) patients is associated with increased mortality and higher costs.

OBJECTIVE

To evaluate occurrences of moderate or severe AKI among patients admitted to the ICU after liver transplantation and investigate characteristics associated with this complication.

DESIGN AND SETTING

Single-center retrospective cohort study in a public hospital, Belo Horizonte, Brazil.

METHODS

Forty-nine patients admitted to the ICU between January 2015 and April 2017 were included. AKI was defined from a modified Kidney Disease Improving Global Outcomes (KDIGO) score (i.e. based exclusively on serum creatinine levels).

RESULTS

Eighteen patients (36.7%) developed AKI KDIGO 2 or 3; mostly KDIGO 3 (16 out of the 18 patients). Lactate level within the first six hours after ICU admission (odds ratio, OR: 1.3; 95% confidence interval, CI: 1.021-1.717; P = 0.034) and blood transfusion requirement within the first week following transplantation (OR: 8.4; 95% CI: 1.687-41.824; P = 0.009) were independently associated with development of AKI. Patients with AKI KDIGO 2 or 3 underwent more renal replacement therapy (72.2% versus 3.2%; P < 0.01), had longer hospital stay (20 days versus 15 days; P = 0.001), higher in-hospital mortality (44.4% versus 6.5%; P < 0.01) and higher mortality rate after one year (44.4% versus 9.7%; P = 0.01).

CONCLUSION

Need for blood transfusion during ICU stay and hyperlactatemia within the first six postoperative hours after liver transplantation are independently associated with moderate or severe AKI. Developing AKI is apparently associated with poor outcomes.

Effect of post-operative goal-directed fluid therapy (GDFT) on organ function after orthotopic liver transplantation: Secondary outcome analysis of the COLT randomised control trial

BACKGROUND

Goal-directed fluid therapy (GDFT) has been shown to reduce the complications following a variety of major surgical procedures, possibly mediated by improved organ perfusion and function. We have shown that it is feasible to randomise patients to GDFT or standard fluid management following liver transplant in the cardiac-output optimisation following liver transplantation (COLT) trial. The current study compares end organ function in patients from the COLT trial who received GDFT in comparison to those receiving standard care (SC) following liver transplant.

METHODS

Adult patients with liver cirrhosis undergoing liver transplantation were randomised to GDFT or SC for the first 12 h following surgery as detailed in a published trial protocol. GDFT protocol was based on stroke volume (SV) optimisation using 250 ml crystalloid boluses. Total fluid administration and time to extubation were recorded. Hourly SV and cardiac output (CO) readings were recorded from the non-invasive cardiac output monitoring (NICOM) device in both groups. Pulmonary function was assessed by arterial blood gas (ABG) and ventilatory parameters. Lung injury was assessed using PaO₂:FiO₂ ratios and calculated pulmonary compliance. The KDIGO score was used for determining acute kidney injury. Renal and liver graft function were assessed during the post-operative period and at 3 months and 1-year.

RESULTS

60 patients were randomised to GDFT (n = 30) or SC (n = 30). All patients completed the 12 h intervention period. GDFT group received a significantly higher total volume of fluid during the 12 h trial intervention period (GDFT 5317 (2335) vs. SC 3807 (1345) ml, p = 0.003); in particular crystalloids (GDFT 3968 (2073) vs. SC 2510 (1027) ml, p = 0.002). There was no evidence of significant difference between the groups in SV or CO during the assessment periods. Time to extubation, PaO2: FIO₂ ratios, pulmonary compliance, ventilatory or blood gas measurements were similar in both groups. There was a significant rise in serum creatinine from baseline (77 μmol/L) compared to first (87 μmol/L, p = 0.039) and second (107 μmol/L, p = 0.001) post-operative days. There was no difference between GDFT and SC in the highest KDIGO scores for the first 7 days post-LT. At 1-year follow-up, there was no difference in need for renal replacement therapy or graft function.

CONCLUSIONS

In this randomised trial of fluid therapy post liver transplant, GDFT was associated with an increased volume of crystalloids administered but did not alter early post-operative pulmonary or renal function when compared with standard care.

Urinary neutrophil gelatinase-associated lipocalin level as a biomarker of acute kidney injury following extracorporeal shock wave lithotripsy

Introduction

Although extracorporeal shock wave lithotripsy (ESWL) is minimally invasive and highly efficient for the management of kidney stones, adverse effects have been described. Available indicators of renal function exhibit insufficient sensitivity in acute renal injury (AKI). We aimed to evaluate the severity of the kidney tissue response to ESWL injury by measuring the urinary neutrophil gelatinase-associated lipocalin (uNGAL), which can indicate AKI in its early phase.

Material and methods

The prospective, controlled study included 62 patients with nephrolithiasis undergoing single ESWL treatment. uNGAL level was measured before the procedure, and 6 h and 12 h after.

Results

The median uNGAL level increased by 126.0%, 6 h after ESWL (p <0.001). The growth rate continued and 12 h after was higher by 583.7%, compared to the pre-treatment level (p <0.001). The median value of estimated glomerular filtration rate (eGFR) dropped by 15.3% 12 h after the treatment (p <0.001). It increased by 5.0% in the period 7 days to 3 months after (p <0.001) and after 3 months it was lower by 10.1% compared to pre-ESWL values (p <0.001). uNGAL level after 12 h was significantly negatively associated with eGFR, 12 h, 7 days and 3 months after the ESWL. The sensitivity of uNGAL 12 h after ESWL was 60.6%; its specificity was 75.0%, with a positive predictive value of 74.0% and negative predictive value of 61.7%.

Conclusions

uNGAL appears to be a useful biomarker for the assessment and prediction of AKI. It was noticed that uNGAL had the highest predictive value 12 h after the ESWL treatment.

Acute Kidney Injury After Liver Transplant: Incidence, Risk Factors, and Impact on Patient Outcomes

OBJECTIVES

Acute kidney injury is a frequent complication of liver transplant. Here, we assessed the rate and contributing factors of acute kidney injury and need for renal replacement therapy in patients undergoing liver transplant at a transplant center in Tehran, Iran.

MATERIAL AND METHODS

We identified all patients who underwent liver transplant at the Imam Khomeini Hospital Complex from March 2018 to March 2019 and who were followed for 3 months after transplant. Acute kidney injury was defined based on the Acute Kidney Injury Network criteria. We collected demographic and pretransplant, intraoperative, and posttransplant data. Univariable and multivariable models were applied to explore independent risk factors for acute kidney injury incidence and need for renal replacement therapy.

RESULTS

Our study included 173 deceased donor liver transplant recipients. Rates of incidence of acute kidney injury and need for renal replacement therapy were 68.2% and 14.5%, respectively. The 3-month mortality rate among those with severe and mild or moderate acute kidney injury was 44.0% (14/25) and 9.7% (9/ 93), respectively (P < .001). Multivariable analyses indicated that serum albumin (relative risk of 0.55; 95% confidence interval, 0.34-0.87; P = .021), baseline serum creatinine (relative risk of 2.11; 95% confidence interval, 1.56-2.90; P = .037), and intraoperative mean arterial pressure (relative risk of 0.76; 95% confidence interval, 0.63-0.82; P = .008) were independent factors for predicting posttransplant acute kidney injury. Independent risk factors for requiring renal replacement therapy were pretransplant serum creatinine (relative risk of 1.99; 95% confidence interval, 1.89-4.47; P = .044) and intraoperative vasopressor infusion (relative risk of 1.41; 95% confidence interval, 1.38-2.00; P = .021).

CONCLUSIONS

We found a high incidence of acute kidney injury among liver transplant recipients in our center. There was a significant association between severity of acute kidney injury and 3-month and in-hospital mortality.

Post-Liver Transplant Acute Kidney Injury

Acute kidney injury (AKI) is a common condition following liver transplantation (LT). It negatively impacts patient outcomes by increasing the chances of developing chronic kidney disease and reducing graft and patient survival rates. Multiple definitions of AKI have been proposed and used throughout the years, with the International Club of Ascites definition being the most widely now used for patients with cirrhosis. Multiple factors are associated with the development of post-LT AKI and can be categorized into pre-LT comorbidities, donor and recipient characteristics, operative factors, and post-LT factors. Many of these factors can be optimized in an attempt to minimize the risk of AKI occurring and to improve renal function if AKI is already present. A special consideration during the post-LT phase is needed for immunosuppression as certain immunosuppressive medications can be nephrotoxic. The calcineurin inhibitor tacrolimus (TAC) is the mainstay of immunosuppression but can result in AKI. Several strategies including use of the monoclonoal antibody basilixamab to allow for delayed initiation of tacrolimus therapy and minimization through combination and minimization or elimination of TAC through combination with mycophenolate mofetil or mammalian target of rapamycin inhibitors have been implemented to reverse and avoid AKI in the post-LT setting. Renal replacement therapy may ultimately be required to support patients until recovery of AKI after LT. Overall, by improving renal function in post-LT patients with AKI, outcomes can be improved.

Acute kidney injury after liver transplantation, perioperative risk factors, and outcome: prospective observational study of 1681 patients (OLTx Study)

BACKGROUND

Acute kidney injury (AKI) represents a frequent complication after orthotopic liver transplantation (OLT). This study aimed to evaluate early postoperative AKI incidence during the first 72 h after OLT, perioperative risk factors, and AKI impact on survival.

METHODS

From January 2011 to December 2013) 1681 patients underwent OLT in 19 centers and were enrolled in this prospective cohort study.

RESULTS

According to RIFLE criteria, AKI occurred in 367 patients, 21.8% (R: 5.8%, I: 6.4%, F: 4.8%, L: 4.8%). Based on multivariate analysis, intraoperative risk factors for AKI were: administration of 5-10 RBCs (OR 1.8, 95%CI 1.3-2.7), dopamine use (OR 1.6, 95%CI 1.2-2.3), post-reperfusion syndrome (OR 1.5, 95%CI 1.0-2.3), surgical complications (OR 2.0, 95% CI 1.3-3.0), and cardiological complications (OR 2.2, 95%CI 1.2-4.0). Postoperative risk factors were: norepinephrine (OR 1.4, 95%CI 1.0-2.0), furosemide (OR 4.2, 95% CI 3.0-5.9), more than 10 RBCs transfusion, (OR 3.7, 95%CI 1.4-10.5), platelets administration (OR 1.6, 95% CI 1.1-2.4), fibrinogen administration (OR 3.0, 95%CI, 1.5-6.2), hepatic complications (OR 4.6, 95%CI 2.9-7.5), neurological complications (OR 2.4, 95%CI 1.5-3.7), and infectious complications (OR 2.7, 95%CI 1.8-4.3). NO-AKI patients' 5 years survival rate was higher than AKI patients (68.06, 95% CI 62.7-72.7 and 81.2, 95% CI 78.9-83.3, p< 0.001).

CONCLUSIONS

AKI still remains an important risk factor for morbidity and mortality after OLT. Further researches to develop new strategies aimed at preventing or minimizing post-OLT AKI are needed.

Different Severity of Clinical Outcomes Between the 2 Subgroups of Stage 1 Acute Kidney Injury After Liver Transplantation

BACKGROUND

Although the Kidney Disease: Improving Global Outcomes (KDIGO) criteria is used to define acute kidney injury (AKI) after liver transplantation, the criteria was criticized for including 2 heterogeneous groups of different serum creatinine (sCr) criteria together in AKI stage 1. We investigated whether there are significant differences in clinical outcomes between 2 subgroups of patients within AKI stage 1.

METHODS

A total of 1440 cases were reviewed. The AKI stage 1 (n = 443) were divided into 2 subgroups based on changes in sCr level (stage 1a: ≥0.3 mg/dL of absolute sCr increase, n = 251; stage 1b: ≥50% relative sCr increase, n = 192). Propensity score analysis was performed between stage 1a and 1b groups, yielding 157 matched pairs. We compared the length of hospital stay, early allograft dysfunction, and 5-year all-cause mortality between these subgroups after matching. Kaplan-Meier analyses were performed to compare the graft or overall survival between the subgroups after matching. Sensitivity analysis for Acute Kidney Injury Network (AKIN) criteria was performed.

RESULTS

Length of hospital stay and 5-year all-cause mortality was significantly worse in patients with stage 1b compared to stage 1a after matching. Five-year graft or patient survival was significantly worse in patients with stage 1b compared to stage 1a after matching (Log-rank test P = 0.022 and P = 0.027, respectively). These results were the same regarding AKIN criteria.

CONCLUSIONS

The KDIGO criteria for AKI stage 1 could be further divided into 2 substages with different severity of clinical outcomes. This modified criteria could give additional prognostic information in patients undergoing liver transplantation.

Polymyxin-induced nephrotoxicity and its predictors: a systematic review and meta-analysis of studies conducted using RIFLE criteria of acute kidney injury

Polymyxins are last-resort antibiotics re-emerged to treat infections caused by multidrug resistant (MDR) and extensively drug-resistant (XDR) Gram-negative bacterial infections. However, polymyxin-associated nephrotoxicity has become the main safety concern. Therefore, we conducted this systematic review and meta-analysis on polymyxin-induced nephrotoxicity and its predictors using studies conducted based on the validated RIFLE (Risk, Injury, Failure, Loss of Function and End-stage renal disease) criteria of acute kidney damage. Literature search was carried out through visiting legitimate databases and indexing services including PubMed, MEDLINE (Ovid®), EMBASE (Ovid®), and Scopus to retrieve relevant studies. Following screening and eligibility evaluation, relevant data were extracted from included studies and analyzed using STATA 15.0 and Rev-Man 5.3. Inverse variance method with random effects pooling model was used for the analysis of outcome measures at 95% confidence interval. Besides, meta-regression, meta-influence, and publication bias analyses were conducted. A total of 48 studies involving 6,199 adult patients aged ≥ 18 years were included for systematic review and meta-analysis. The pooled incidence of polymyxin-induced nephrotoxicity was found to be 45% (95% CI: 41- 49%; I² = 92.52%). Stratifying with RIFLE severity scales, pooled estimates of polymyxin-treated patients identified as 'risk', 'injury' and 'failure' were 17% (95% CI: 14-20%), 13% (95% CI: 11-15%), and 10% (95% CI: 9-11%), respectively. Besides, the pooled incidence of colistin-induced nephrotoxicity was about 48% (95% CI: 42-54%), whereas that of polymyxin B was 38% (95% CI: 32-44%). Likewise, colistin had 37% increased risk of developing nephrotoxicity compared to the polymyxin B treated cohorts (RR = 1.37, 95% CI: 1.13-1.67; I² = 57%). Older age (AOR = 1.03, 95% CI: 1.01-1.05), daily dose (AOR = 1.46, 95% CI: 1.09-1.96), underlying diabetes mellitus (AOR = 1.81, 95% CI: 1.25-2.63), and concomitant nephrotoxic drugs (AOR = 2.31, 95% CI: 1.79-3.00) were independent risk factors for polymyxin-induced nephrotoxicity. Patients with high serum albumin level were less likely (AOR = 0.69, 95% CI: 0.56-0.85] to experience nephrotoxicity compared to those with low albumin level. Despite the resurgence of these antibiotics for the chemotherapy of MDR/XDR-Gram-negative superbugs, the high incidence of nephrotoxicity has become a contemporary clinical concern. Being elderly, high daily dose, having underlying diseases such as diabetes, and use of concomitant nephrotoxic drugs were independent predictors of nephrotoxicity. Therefore, therapeutic drug monitoring should be done to these patients to outweigh the potential benefits of polymyxin therapy from its risk.

Impact of Everolimus-based Immunosuppression on Renal Function in Liver Transplant Recipients

BACKGROUND

Calcineurin inhibitors have been implicated in acute and chronic kidney disease after liver transplant (LT). Everolimus (EVR) is a mammalian target of rapamycin inhibitor efficacious in preventing acute cellular rejection while preserving renal function among LT recipients. We evaluated the benefits on renal function of EVR immunosuppression in LT recipients.

METHODS

We performed a retrospective and observational study in 477 LT recipients in Virgen de las Nieves Hospital from 2002 to 2019 on the use of EVR with tacrolimus minimization or withdrawal in LT recipients with renal dysfunction. The study included 100 patients starting EVR (20.96%); in 66 (66%) the indication was renal dysfunction. The change in renal function was assessed by estimated glomerular filtration rate. Statistical analyses were performed using SPSS 17.0 software (IBM, Munich, Germany).

RESULTS

Fifty 8 patients received mycophenolate mofetil (87.8%), and tacrolimus therapy was stopped in 27 patients (40.9%). Induction therapy with basiliximab was administered in 41 patients (62.12%). There was significant difference between estimated glomerular filtration rate at the time of starting EVR and the first month at last follow-up (49.42 mL/min/1.73 m² vs 75.27 mL/min/1.73 m²; P < .001) and at end of follow-up (24 months) (49.42 mL/min/1.73 m² vs 64.32 mL/min/1.73 m²; P = .001). The rate of incidence of adverse events was 48.48% (32/66). Seven patients died during follow-up (10.6%), but there were no EVR-related deaths. Eleven patients (16.6%) developed biopsy-proven acute rejection.

CONCLUSION

This study showed that EVR is associated with a beneficial effect on glomerular filtration rate in both the short and long term in LT recipients.

Acute Kidney Injury After Pediatric Liver Transplantation

BACKGROUND

The aim of the present study is to assess acute kidney injury (AKI) incidence according to the pRIFLE and AKIN criteria and to evaluate the risk factors for early developing AKI in postoperative intensive care unit after pediatric liver transplantation (LT).

MATERIALS

After exclusion of retransplantations, 7 cadaveric and 44 living donors, totaling 51 pediatric LT patients that were performed between 2005 and 2017, were reviewed retrospectively. AKI was defined according to both pediatric RIFLE (Risk for renal dysfunction, Injury to the kidney, Failure of kidney function, Loss of kidney function, and End-stage renal disease) and Acute Kidney Injury Network (AKIN) criteria. Documented data were compared between AKI and non-AKI patients.

RESULTS

AKI incidences were 17.6% by AKIN and 37.8% by pRIFLE criteria. AKIN-defined AKI group had statistically lower serum albumin level, higher serum sodium level, higher furosemide dose, and higher rate of red blood cell (RBC) transfusion than the non-AKI group (P = .02, P = .02, P = .01 and P = .04, respectively). AKI patients had significantly prolonged mechanical ventilation (P = .01) and hospital LOS (P = .02). The pRIFLE-defined AKI group had significantly lower serum albumin level, higher blood urea nitrogen (BUN) level, and higher ascites drained and also showed higher requirement for RBC and 20% human albumin transfusions than the non-AKI group (P = .02, P = .04, P: =.007, P = .02 and P = .05, respectively).

CONCLUSION

We evaluated that hypoalbuminemia, high requirement for RBC and 20% human albumin transfusions, high serum sodium, high furosemide use, and high flow of ascites are risk factors for AKI and high BUN levels can be predictive for AKI in pediatric LT patients. The effect of AKI on outcome variables were prolonged mechanical ventilation and hospital LOS.

Incidence and Impact of Acute Kidney Injury after Liver Transplantation: A Meta-Analysis

Background: The study’s aim was to summarize the incidence and impacts of post-liver transplant (LTx) acute kidney injury (AKI) on outcomes after LTx. Methods: A literature search was performed using the MEDLINE, EMBASE and Cochrane Databases from inception until December 2018 to identify studies assessing the incidence of AKI (using a standard AKI definition) in adult patients undergoing LTx. Effect estimates from the individual studies were derived and consolidated utilizing random-effect, the generic inverse variance approach of DerSimonian and Laird. The protocol for this systematic review is registered with PROSPERO (no. CRD42018100664). Results: Thirty-eight cohort studies, with a total of 13,422 LTx patients, were enrolled. Overall, the pooled estimated incidence rates of post-LTx AKI and severe AKI requiring renal replacement therapy (RRT) were 40.7% (95% CI: 35.4%–46.2%) and 7.7% (95% CI: 5.1%–11.4%), respectively. Meta-regression showed that the year of study did not significantly affect the incidence of post-LTx AKI (p = 0.81). The pooled estimated in-hospital or 30-day mortality, and 1-year mortality rates of patients with post-LTx AKI were 16.5% (95% CI: 10.8%–24.3%) and 31.1% (95% CI: 22.4%–41.5%), respectively. Post-LTx AKI and severe AKI requiring RRT were associated with significantly higher mortality with pooled ORs of 2.96 (95% CI: 2.32–3.77) and 8.15 (95%CI: 4.52–14.69), respectively. Compared to those without post-LTx AKI, recipients with post-LTx AKI had significantly increased risk of liver graft failure and chronic kidney disease with pooled ORs of 3.76 (95% CI: 1.56–9.03) and 2.35 (95% CI: 1.53–3.61), respectively. Conclusion: The overall estimated incidence rates of post-LTx AKI and severe AKI requiring RRT are 40.8% and 7.0%, respectively. There are significant associations of post-LTx AKI with increased mortality and graft failure after transplantation. Furthermore, the incidence of post-LTx AKI has remained stable over the ten years of the study.

Predictive Value of Serum Creatinine, Blood Urea Nitrogen, Uric Acid, and β2-Microglobulin in the Evaluation of Acute Kidney Injury after Orthotopic Liver Transplantation

Background

As a major complication after orthotopic liver transplantation (OLT), the occurrence of acute kidney injury (AKI) is frequently defined by serum creatinine (Cr); however, the accuracy of commonly used blood urea nitrogen (BUN), uric acid (UA), and β₂-microglobulin (β₂-MG) remains to be explored. This retrospective study compared the accuracy of these parameters for post-OLT AKI evaluation.

Methods

Patients who underwent OLT in three centers between July 2003 and December 2013 were enrolled. The postoperative AKI group was diagnosed by the Kidney Disease Improving Global Outcomes (KDIGO) criteria and classified by stage. Measurement data were analyzed using the t-test or Wilcoxon rank-sum test; enumerated data were analyzed using the Chi-square test or Fisher's exact test. Diagnostic reliability and predictive accuracy were evaluated using receiver operating characteristic (ROC) curve analysis.

Results

This study excluded 976 cases and analyzed 697 patients (578 men and 119 women); the post-OLT AKI incidence was 0.409. Compared with the no-AKI group, the AKI group showed very significant differences in Model for End-stage Liver Disease score (14.74 ± 9.91 vs. 11.07 ± 9.54, Z = 5.404; P < 0.001), hepatic encephalopathy (45 [15.8%] vs. 30 [7.3%], χ² = 12.699; P < 0.001), hemofiltration (28 [9.8%] vs. 0 [0.0%], χ² = 42.171; P < 0.001), and 28-day mortality (23 [8.1%] vs. 9 [2.2%], χ² = 13.323; P <0.001). Moreover, mean values of Cr, BUN, UA, and β₂-MG in the AKI group differed significantly at postoperative days 1, 3, and 7 (all P < 0.001). ROC curve area was 0.847 of Cr for the detection of AKI Stage 1 (sensitivity 80.1%, specificity 75.7%, cutoff value 88.23 μmol/L), 0.916 for Stage 2 (sensitivity 87.6%, specificity 82.6%, cutoff value 99.9 μmol/L), and 0.972 for Stage 3 (sensitivity 94.1%, specificity 88.2%, cutoff value 122.90 μmol/L).

Conclusion

The sensitivity and specificity of serum Cr might be a high-value indicator for the diagnosis and grading of post-OLT AKI.

PREOPERATIVE RISK FACTORS FOR ACUTE KIDNEY INJURY AFTER LIVER TRANSPLANTATION: RESULTS FROM A CROSS-SECTIONAL STUDY IN NORTHEAST OF BRAZIL

BACKGROUND

Acute kidney injury (AKI) is a common complication in the immediate postoperative period of patients undergoing liver transplantation.

OBJECTIVE

The aim of this study was to evaluate preoperative risk factors for AKI after liver transplantation.

METHODS

A cross-sectional study was conducted with adults submitted to orthotopic liver transplantation at a reference hospital in Fortaleza, Northeast of Brazil, from January to December 2016. Preoperative risk factors were evaluated for AKI development in the immediate postoperative period. AKI was defined according to the Kidney Disease: Improving Global Outcomes (KDIGO) criteria.

RESULTS

A total of 40 patients were included in the study. AKI was found in 85% of patients in the first 24 hours after transplantation, most of them (40%) classified in KDIGO stage 1. Preoperative data indicate that serum albumin levels were lower in the KDIGO stage 3 group compared to the non-AKI group, as well as the hematocrit levels. Direct bilirubin (DB) was higher in the KDIGO stage 3 group compared to the group without AKI, as well as alkaline phosphatase (AP) and gamma-glutamiltransferase (GGT). In a logistic regression analysis independent risk factors for AKI were increase levels of AP, GGT and DB and decrease level of serum albumin.

CONCLUSION

Low levels of serum albumin, and elevated levels of DB, AP and GGT in the preoperative period are risk factors for AKI development after liver transplantation.

The Association of Preoperative Body Mass Index with Acute Kidney Injury in Liver Transplantation Recipients: A Retrospective Study

Background

Liver transplantation (LT) is a complicated procedure with a high incidence of postoperative acute kidney injury (AKI). Previous studies indicate that even transient or mild post-LT AKI can result in critical conditions, including prolonged stays in hospitals and intensive care units and increased morbidity and mortality. The aim of this study was to investigate the association between body mass index (BMI) and occurrence of AKI in LT recipients.

Methods

Medical data from 203 patients who received LT surgery from January 2010 to August 2016 in a single university hospital setting were retrospectively collected and analyzed. Patients were classified as either underweight (BMI <20 kg/m²) or normal weight (20 ≤ BMI < 30 kg/m²). Demographic data, anesthetic methods, complications, and perioperative laboratory test values of each patient were assessed. Propensity analyses and logistic regression were performed to evaluate the association between BMI and post-LT AKI.

Results

There was no significant difference in occurrence of post-LT AKI between underweight and normal weight patients. The underweight patient group had significantly longer hospital stay compared with the normal weight patient group (P = 0.023).

Conclusions

BMI classification was neither a positive nor negative predictor of postoperative AKI occurrence. However, patients with lower BMI had significantly longer hospital stay compared with their counterparts. Although our study was limited by its retrospective design, our observations suggest that lower BMI might play a role in post-LT AKI.

Influence of oxygen content immediately after graft reperfusion on occurrence of postoperative acute kidney injury in living donor liver transplantation

Acute kidney injury (AKI) is a common complication after living donor liver transplantation (LDLT). In this study, we investigated perioperative factors, including oxygen content, related to the postoperative development of AKI after LDLT. The perioperative data of 334 patients were reviewed retrospectively. We identified the postoperative development of AKI based on the Acute Kidney Injury Network criteria. Perioperative variables, including oxygen content, were compared between patients with and without AKI. Potentially significant variables in a univariate analysis were evaluated by multivariate analysis. Postoperative AKI developed in 76 patients (22.7%). Univariate analysis revealed that preoperative factors (body mass index [BMI], diabetes mellitus, C-reactive protein) and intraoperative factors (severe postreperfusion syndrome, packed red blood cell transfusion, furosemide, and oxygen content at the anhepatic phase, 5 minutes and 1 hour after graft reperfusion, and at peritoneal closure) of recipients were significant. The multivariate analysis showed that oxygen content 5 minutes after graft reperfusion, BMI, and furosemide administration were independently associated with postoperative AKI. In conclusion, postoperative AKI was independently associated with oxygen content 5 minutes after graft reperfusion, BMI, and furosemide administration. Meticulous ventilator care and transfusion should be required to maintain sufficient oxygen content immediately after graft reperfusion in patients who undergo LDLT.