Prevalence and predictors of acute renal injury in liver transplant recipients

Predictive Role of the D-Dimer Level in Acute Kidney Injury in Living Donor Liver Transplantation: A Retrospective Observational Cohort Study

This study aimed to determine the association between serum D-dimer levels and the risk of acute kidney injury (AKI) in patients undergoing living donor liver transplantation (LDLT). Clinical data of 675 patients undergoing LDLT were retrospectively analyzed. The exclusion criteria included a history of kidney dysfunction, emergency cases, and missing data. The final study population of 617 patients was divided into the normal and high D-dimer groups (cutoff: 0.5 mg/L). After LDLT, 145 patients (23.5%) developed AKI. A high D-dimer level (>0.5 mg/L) was an independent predictor of postoperative development of AKI in the multivariate analysis when combined with diabetes mellitus [DM], platelet count, and hourly urine output. AKI was significantly higher in the high D-dimer group than in the normal D-dimer group (odds ratio [OR], 2.792; 95% confidence interval [CI], 1.227-6.353). Patients with a high D-dimer exhibited a higher incidence of early allograft dysfunction, longer intensive care unit stay, and a higher mortality rate. These results could improve the risk stratification of postoperative AKI development by encouraging the determination of preoperative D-dimer levels in patients undergoing LDLT.

Predictive utility of fibrinogen in acute kidney injury in living donor liver transplantation: A propensity score-matching analysis

Background

This study investigated the association between the fibrinogen level and the risk of acute kidney injury (AKI) in patients who have undergone living donor liver transplantation (LDLT).

Patients and methods

A total of 676 patients who underwent LDLT were analyzed retrospectively. Exclusion criteria included a history of severe kidney dysfunction, emergency operation, deceased donor, ABO-incompatible transplantation, and missing data. The study population was divided into low and normal fibrinogen groups. A 1:1 propensity score (PS) matching analysis was used to evaluate the association between a low fibrinogen level (< 160 mg/dL) and postoperative development of AKI.

Results

In total, 142 patients (23.1%) developed AKI after LDLT. The PS matching analysis showed that the probability of AKI was two-fold higher in the low fibrinogen group than in the normal fibrinogen group. In addition, patients with AKI had poorer postoperative outcomes such as longer hospitalization, longer ICU stay, and higher mortality than patients without AKI.

Conclusions

The preoperative fibrinogen level may be useful for risk stratification of patients undergoing LDLT in terms postoperative development of AKI.

Predictive Utility of Antithrombin III in Acute Kidney Injury in Living-Donor Liver Transplantation: A Retrospective Observational Cohort Study

INTRODUCTION

This study was performed to determine the association between the serum level of antithrombin III (ATIII) level and the risk of acute kidney injury (AKI) in patients undergoing living-donor liver transplantation (LDLT).

PATIENTS AND METHODS

A total of 591 patients undergoing LDLT were retrospectively investigated and 14 patients were excluded because of a history of kidney dysfunction or missing data; 577 patients were finally enrolled in the study. The study population was divided into normal and low ATIII groups. Data on all laboratory variables, including ATIII, were collected on the day before surgery.

RESULTS

After LDLT, 143 patients developed AKI (24.8%). A lower ATIII was independently associated with postoperative AKI along with preoperative (diabetes mellitus) and intraoperative (mean heart rate, hourly urine output) factors. Based on the standard cutoff for normal ATIII (<70%), the probability of AKI was 2.8-fold higher in the low ATIII group than in the normal ATIII group. In addition, patients with low ATIII received blood transfusion products during the operation and underwent longer duration mechanical ventilation.

CONCLUSIONS

Preoperative ATIII measurement will help improve risk stratification for postoperative AKI development in patients undergoing LDLT.

Predictive role of vitamin B12 in acute kidney injury in living donor liver transplantation: a propensity score matching analysis

OBJECTIVES

We examine the association between vitamin B₁₂ level and risk for acute kidney injury (AKI) in patients undergoing living donor liver transplantation (LDLT).

DESIGN

Retrospective observational cohort study.

SETTING

University hospital, from January 2009 to December 2018.

PARTICIPANTS

A total of 591 patients who underwent elective LDLT were analysed in this study. Those with a preoperative history of kidney dysfunction, vitamin B₁₂ supplementation due to alcoholism, low vitamin B₁₂ (<200 pg/mL) or missing laboratory data were excluded.

PRIMARY AND SECONDARY OUTCOME MEASURES

The population was classified into AKI and non-AKI groups according to Kidney Disease Improving Global Outcomes (KDIGO) criteria, and associations between perioperative factors and AKI were analysed. After 1:1 propensity score (PS) matching, the association between high vitamin B₁₂ (>900 pg/mL) and postoperative AKI was evaluated.

RESULTS

Preoperative vitamin B₁₂ was higher in the AKI group. Potentially significant perioperative factors from univariate analyses were entered into multivariate analyses, including preoperative factors (vitamin B₁₂, diabetes), intraoperative factors (hourly urine output) and donor graft fatty change in LDLT patients. PS matching analyses with adjustment using PS revealed that high serum vitamin B₁₂ (>900 pg/mL) was associated with risk for AKI, and the risk was 2.8-fold higher in patients with high vitamin B₁₂ than in those with normal vitamin B₁₂. Higher vitamin B₁₂ was also related to a higher AKI stage. In addition, inflammatory factors (C reactive protein, white blood cells and albumin) were associated with vitamin B₁₂ level.

CONCLUSIONS

Our study may improve the accuracy of predicting postoperative AKI by introducing preoperative vitamin B₁₂ into risk assessments for patients undergoing LDLT.

Medical management of metabolic and cardiovascular complications after liver transplantation

Liver transplantation represents the only curative option for patients with end-stage liver disease, fulminant hepatitis and advanced hepatocellular carcinoma. Even though major advances in transplantation in the last decades have achieved excellent survival rates in the early post-transplantation period, long-term survival is hampered by the lack of improvement in survival in the late post transplantation period (over 5 years after transplantation). The main etiologies for late mortality are malignancies and cardiovascular complications. The latter are increasingly prevalent in liver transplant recipients due to the development or worsening of metabolic syndrome and all its components (arterial hypertension, dyslipidemia, obesity, renal injury, etc.). These comorbidities result from a combination of pre-liver transplant features, immunosuppressive agent side-effects, changes in metabolism and hemodynamics after liver transplantation and the adoption of a sedentary lifestyle. In this review we describe the most prevalent metabolic and cardiovascular complications present after liver transplantation, as well as proposing management strategies.

Intraoperative continuous renal replacement therapy during liver transplantation: a pilot randomized-controlled trial (INCEPTION)

PURPOSE

To evaluate the feasibility of intraoperative continuous renal replacement therapy (IoCRRT) during liver transplantation (LT), in terms of recruitment, protocol adherence, and ascertainment of follow-up.

METHODS

In this pilot randomized open-label controlled trial in adults receiving LT with a Model for End-Stage Liver Disease (MELD) score ≥ 25 and preoperative acute kidney injury (RIFLE - RISK or higher) and/or estimated glomerular filtration rate < 60 mL·min^-1·1.73 m^-2, patients were randomized to receive IoCRRT or standard of care (SOC). Primary endpoints were feasibility and adverse events. Primary analysis was intention-to-treat (n = 32) and secondary analysis was per-protocol (n = 28).

RESULTS

The trial was stopped early because of slow patient accrual and inadequate funding. Sixty patients were enrolled and 32 (53%) were randomized (n = 15 IoCRRT; n = 17 SOC). Mean (standard deviation) MELD was 36 (8), 81% (n = 26) had cirrhosis; 69% (n = 22) received preoperative RRT; 66% (n = 21) received LT from the intensive care unit. Four patients (n = 2 IoCRRT, n = 2 SOC) did not receive LT post-randomization. Seven patients (41%) allocated to SOC crossed over intraoperatively to IoCRRT. Three patients were lost to follow-up at one year. No adverse events occurred related to IoCRRT. There were no differences in survival at one year (IoCRRT, 71% [n = 10/14] vs SOC, 93% [n = 14/15]; risk ratio, 0.77; 95% confidence interval, 0.54 to 1.1). In the per-protocol analysis (n = 28 received IoCRRT after randomization - n = 20 IoCRRT, n = 8 SOC), one-year survival was 92% and perioperative complications were similar between groups. Only one patient was receiving dialysis one year after LT.

CONCLUSION

In this pilot randomized trial, IoCRRT was feasible and safe with no difference in complications. Crossover rates were high. Despite high preoperative severity of illness, one-year survival was excellent. These data can inform the design of a larger multicentre trial.

TRIAL REGISTRATION

www.clinicalTrials.gov (NCT01575015); registered 12 April, 2012.

Renal Dysfunction after Living-Donor Liver Transplantation: Experience with 500 Cases

Introduction. The possible risk factors for chronic kidney disease in transplant recipients have not been thoroughly investigated after living-donor liver transplantation. Material and Methods. A retrospective cohort study of consecutive adults who underwent living-donor liver transplantation between May 2004 and October 2016, in a single center, was conducted. Kidney function was investigated successively for all the patients throughout the study period, with 12 months being the shortest follow-up. Postoperative renal dysfunction was defined in accordance with the Chronic Kidney Disease Epidemiology Collaboration criteria. The patients' demographic data, preoperative and intraoperative parameters, and outcomes were recorded. A calcineurin inhibitor-based immunosuppressive regimen, either tacrolimus or cyclosporine, was used in all the patients. Results. Of the 413 patients included in the study, 33 (8%) who survived for ≥1 year experienced chronic kidney disease 1 year after living-donor liver transplantation. Twenty-seven variables were studied to compare between the patients with normal kidney functions and those who developed chronic kidney disease 1 year after living-donor liver transplantation. Univariate regression analysis for predicting the likelihood of chronic kidney disease at 1 year revealed that the following 4 variables were significant: operative time, P < 0.0005; intraoperative blood loss, P < 0.0005; preoperative renal impairment, P = 0.001; and graft-to-recipient weight ratio (as a negative predictor), P < 0.0005. In the multivariate regression analysis, only 2 variables remained as independent predictors of chronic kidney disease at 1 year, namely, operative time with a cutoff value of ≥714 minutes and graft-to-recipient weight ratio as a negative predictor with a cutoff value of <0.91. Conclusion. In this study, prolonged operative time and small graft-to-recipient weight ratio were independent predictors of chronic kidney disease at 1 year after living-donor liver transplantation.

Acute kidney injury following liver transplantation: a systematic review of published predictive models

Acute kidney injury is a frequent postoperative complication amongst liver transplant recipients and is associated with increased morbidity and mortality. This systematic review analysed the existing predictive models, in order to solidify current understanding. Articles were selected for inclusion if they described the primary development of a clinical prediction model (either an algorithm or risk score) to predict AKI post liver transplantation. The database search yielded a total of seven studies describing the primary development of a prediction model or risk score for the development of AKI following liver transplantation. The models span thirteen years of clinical research and highlight a gradual change in the definitions of AKI, emphasising the need to employ standardised definitions for subsequent studies. Collectively, the models identify a diverse range of predictive factors with several common trends. They emphasise the impact of preoperative renal dysfunction, liver disease severity and aetiology, metabolic risk factors as well as intraoperative variables including measures of haemodynamic instability and graft quality. Although several of the models address postoperative parameters, their utility in predictive modelling seems to be of questionable relevance. The common risk factors identified within this systematic review provide a minimum list of variables, which future studies should address. Research in this area would benefit from prospective, multi-site studies with larger cohorts as well as the subsequent internal and external validation of predictive models. Ultimately, the ability to identify patients at high risk of post-transplant AKI may enable early intervention and perhaps prevention.

Incidence and risk factors for early renal dysfunction after liver transplantation

AIM: To determine renal dysfunction post liver transplantation, its incidence and risk factors in patients from a Belgian University Hospital.

METHODS: Orthotopic liver transplantations performed from January 2006 until September 2012 were retrospectively reviewed (n = 187). Patients with no renal replacement therapy (RRT) before transplantation were classified into four groups according to their highest creatinine plasma level during the first postoperative week. The first group had a peak creatinine level below 12 mg/L, the second group between 12 and 20 mg/L, the third group between 20 and 35 mg/L, and the fourth above 35 mg/L. In addition, patients who needed RRT during the first week after transplantation were also classified into the fourth group. Perioperative parameters were recorded as risk factors, namely age, sex, body mass index (BMI), length of preoperative hospital stay, prior bacterial infection within one month, preoperative ascites, preoperative treatment with β-blocker, angiotensin-converting enzyme inhibitor or non steroidal anti-inflammatory drugs, preoperative creatinine and bilirubin levels, donor status (cardiac death or brain death), postoperative lactate level, need for intraoperative vasopressive drugs, surgical revision, mechanical ventilation for more than 24 h, postoperative bilirubin and transaminase peak levels, postoperative hemoglobin level, amount of perioperative blood transfusions and type of immunosuppression. Univariate and multivariate analysis were performed using logistic ordinal regression method. Post hoc analysis of the hemostatic agent used was also done.

RESULTS: There were 78 patients in group 1 (41.7%), 46 in group 2 (24.6%), 38 in group 3 (20.3%) and 25 in group 4 (13.4%). Twenty patients required RRT: 13 (7%) during the first week after transplantation. Using univariate analysis, the severity of renal dysfunction was correlated with presence of ascites and prior bacterial infection, preoperative bilirubin, urea and creatinine level, need for surgical revision, use of vasopressor, postoperative mechanical ventilation, postoperative bilirubin and urea, aspartate aminotransferase (ASAT), and hemoglobin levels and the need for transfusion. The multivariate analysis showed that BMI (OR = 1.1, P = 0.004), preoperative creatinine level (OR = 11.1, P < 0.0001), use of vasopressor (OR = 3.31, P = 0.0002), maximal postoperative bilirubin level (OR = 1.44, P = 0.044) and minimal postoperative hemoglobin level (OR = 0.059, P = 0.0005) were independent predictors of early post-liver transplantation renal dysfunction. Neither donor status nor ASAT levels had significant impact on early postoperative renal dysfunction in multivariate analysis. Absence of renal dysfunction (group 1) was also predicted by the intraoperative hemostatic agent used, independently of the extent of bleeding and of the preoperative creatinine level.

CONCLUSION: More than half of receivers experienced some degree of early renal dysfunction after liver transplantation. Main predictors were preoperative renal dysfunction, postoperative anemia and vasopressor requirement.

Intraoperative terlipressin therapy reduces the incidence of postoperative acute kidney injury after living donor liver transplantation

OBJECTIVE

To evaluate the effect of intraoperative infusion with terlipressin on the incidence of acute kidney injury (AKI) after living donor liver transplantation (LDLT).

DESIGN

Retrospective case-controlled study.

SETTING

Government hospital.

PARTICIPANTS

The medical records of 303 patients who underwent LDLT were reviewed retrospectively.

INTERVENTIONS

Patients were divided into 2 groups on the basis of intraoperative administration of terlipressin. The primary outcome was AKI, as defined by the Acute Kidney Injury Network criteria. Secondary outcomes included the requirement for postoperative dialysis and in-hospital mortality.

MEASUREMENTS AND MAIN RESULTS

The incidence of AKI was 38% (n = 115); AKI occurred in 24 (24.2%) patients who received terlipressin versus 91 (44.6%) in the control group (p = 0.001). The incidence of postoperative dialysis was 9.2% (n = 28). Postoperative dialysis was needed by 8 patients (8.1%) in the terlipressin group versus 20 patients (9.8%) in the control group (p = 0.62). Multivariate logistic regression analysis indicated that terlipressin protected against AKI (odds ratio [OR], 0.4; 95% confidence interval [CI], 0.2-0.8; p = 0.013) but not the need for dialysis (OR, 0.7; 95% CI, 0.2-2.2; p = 0.53) or the in-hospital mortality (OR, 1.1; 95% CI, 0.5-2.3; p = 0.7). Adjustment, using the propensity score, did not alter the association between the use of terlipressin and AKI reduction (OR, 0.46; 95% CI, 0.22-0.89; p = 0.03).

CONCLUSION

These results suggested that intraoperative terlipressin therapy is associated with significant reductions in the risk of AKI in LDLT patients.

Anesthetic concerns in patients presenting with renal failure

Anesthesiologists often care for patients with renal insufficiency or renal failure. These patients may present to the operating room for a minor procedure such as an inguinal hernia repair or an arteriovenous fistula/graft. Alternatively, they may present for major abdominal operations or coronary artery bypass grafting. Critically ill patients presenting to the operating room may have acute kidney injury. It is imperative that the anesthesiologist understands the ramifications of renal failure and adjusts the anesthetic plan accordingly. Hemodynamic monitoring and fluid management can be challenging in this patient population. Various metabolic abnormalities can ensue that the anesthesiologist must be able to manage in the acute setting of the operating room.