Risk factors of acute renal failure after liver transplantation

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.

Acute Renal Injury Evaluation After Liver Transplantation: With RIFLE Criteria

BACKGROUND

The aim of this study was to identify acute renal injury (ARI) through the use of RIFLE (risk, injury, failure, loss, end-stage kidney disease) criteria and to investigate perioperative risk factors for ARI in liver transplantation (LT).

METHODS

We reviewed medical records of adult LT patients retrospectively. Postoperative ARI was staged with RIFLE criteria by the 1st and 7th days of the surgery.

RESULTS

We analyzed 440 adult LT patients, categorized as risk (R), injury (I), or failure (F) according to the RIFLE criteria. In this study, in the first postoperative day, incidence of ARI was 7.95%; all of them were R-class, and, on the 7th day, the incidence of ARI was 7.27%, as R-class 6.59% and I-class 0.68%. Significant risk factors were detected within the first postoperative day including pre-operative hemoglobin levels <9 g/dL (P = .019), intra-operative transfusion of red blood cells (RBCs) (P = .049) and fresh-frozen plasma (FFP) (P = .049), blood loss (P = .011), and post-reperfusion syndrome (P = .023). Multivariate analysis revealed risk factors for ARI as RBCs (odds ratio [OR], 1.049; P = .247) and FFP (OR, 1.017; P = .627) transfusion and blood loss (OR, 1.000; P = .021) (blood loss OR: 0.9996952300184; 95% confidence interval: 0.9994356774026 to 0.999548500399). The only significant risk factor for the 7th postoperative day was the Model for End-Stage Liver Disease (MELD) score (>20) (P = .002).

CONCLUSIONS

This study showed that RBC and FFP transfusion, perioperative blood loss, and MELD score >20 are risk factors for LT-related ARI. Also normalization of hemoglobin levels with non-blood products in patients with preoperative low hemoglobin levels can diminish the need for RBC and that can prevent ARI.

Hypoalbuminemia Within Two Postoperative Days Is an Independent Risk Factor for Acute Kidney Injury Following Living Donor Liver Transplantation: A Propensity Score Analysis of 998 Consecutive Patients

OBJECTIVE

Acute kidney injury is a known major complication of liver transplantation. Previous reports have shown that hypoalbuminemia is associated with an increased risk of acute kidney injury. However, little is known about the relationship between the early postoperative albumin level and acute kidney injury after living donor liver transplantation. The aim of this study was to identify the influence of the postoperative albumin level on acute kidney injury prevalence after living donor liver transplantation.

DESIGN

A retrospective analysis.

SETTING

A tertiary care university hospital.

PATIENTS

Nine hundred and ninety-eighty patients underwent living donor liver transplantation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We divided the enrolled patients into two groups: group 1 included patients whose postoperative albumin level was less than 3.0 g/dL (n = 522), and group 2 included patients with an albumin level greater than or equal to 3.0 g/dL (n = 476). The prevalence of acute kidney injury, major adverse cardiac events, hospital stay, ICU stay, 30-day mortality, and overall mortality was analyzed using inverse probability of treatment weighting and propensity-score matching (n = 249 pairs) analysis. The prevalence of acute kidney injury was higher in group 1 defined by both Acute Kidney Injury Network (after adjusting for inverse probability of treatment weighting [n = 364; 69.7%] and propensity-score matching [n = 152; 61.0%]) and Risk, Injury, Failure, Loss, and End-stage kidney disease criteria (after adjusting for inverse probability of treatment weighting [n = 419; 80.3%] and propensity-score matching [n = 190; 76.3%]). The overall mortality was higher in group 1 after adjusting for inverse probability of treatment weighting (n = 61; 11.7%) and propensity-score matching (n = 23; 9.2%). The hospital (p < 0.001) and ICU (p = 0.006) stays were significantly prolonged in group 1. Acute kidney injury was associated with ICU stay by the Acute Kidney Injury Network criteria (p = 0.034), and overall mortality was correlated with acute kidney injury by the Risk, Injury, Failure, Loss, and End-stage kidney disease criteria (p = 0.014).

CONCLUSIONS

Early postoperative hypoalbuminemia is an independent risk factor for acute kidney injury, and postoperative acute kidney injury is related to postoperative ICU stay and overall mortality after living donor liver transplantation.

Evaluation of renal functions in pediatric liver transplantation

AKI is an important complication after LT. As our LT series contains a quite high number of children with ALF unlike published studies, we aimed to determine pre-LT and long-term renal functions in children both with ALF and with CLD. Demographic and disease-related data of 134 transplanted children were evaluated retrospectively. Pre-LT and follow-up GFR and pediatric RIFLE scores were determined. Mean pre-LT GFR was not dependent on the disease presentation or severity of chronic disease. While there was an initial decline until first week of post-LT in CLD children, an increase was observed in ALF. Neither mean GFR nor the pRIFLE on follow-up was different with respect to the type of LT or disease presentation. Mean GFR at first and sixth months were lower in children on cyclosporine compared to tacrolimus (p = 0.001 and p = 0.002, respectively). In conclusion, GFR-time curve was different in children with or without ALF. Type of LT, and severity of the CLD were not risk factors for CKD in any time, but younger age at LT, CLD, and cyclosporine usage were at sixth months of follow-up.

Modulation of splanchnic circulation: Role in perioperative management of liver transplant patients

Splanchnic circulation is the primary mechanism that regulates volumes of circulating blood and systemic blood pressure in patients with cirrhosis accompanied by portal hypertension. Recently, interest has been expressed in modulating splanchnic circulation in patients with liver cirrhosis, because this capability might produce beneficial effects in cirrhotic patients undergoing a liver transplant. Pharmacologic modulation of splanchnic circulation by use of vasoconstrictors might minimize venous congestion, replenish central blood flow, and thus optimize management of blood volume during a liver transplant operation. Moreover, splanchnic modulation minimizes any high portal blood flow that may occur following liver resection and the subsequent liver transplant. This effect is significant, because high portal flow impairs liver regeneration, and thus adversely affects the postoperative recovery of a transplant patient. An increase in portal blood flow can be minimized by either surgical methods (e.g., splenic artery ligation, splenectomy or portocaval shunting) or administration of splanchnic vasoconstrictor drugs such as Vasopressin or terlipressin. Finally, modulation of splanchnic circulation can help maintain perioperative renal function. Splanchnic vasoconstrictors such as terlipressin may help protect against acute kidney injury in patients undergoing liver transplantation by reducing portal pressure and the severity of a hyperdynamic state. These effects are especially important in patients who receive a too small for size graft. Terlipressin selectively stimulates V1 receptors, and thus causes arteriolar vasoconstriction in the splanchnic region, with a consequent shift of blood from splanchnic to systemic circulation. As a result, terlipressin enhances renal perfusion by increasing both effective blood volume and mean arterial pressure.

Evaluation of perioperative predictors of acute kidney injury post orthotopic liver transplantation

Acute kidney injury (AKI) is a common complication following orthotopic liver transplantation. It is associated with increased morbidity and mortality, as well as increased healthcare costs. The aetiology of AKI post liver transplantation is multifactorial and understanding these factors is pivotal in developing risk stratification and prevention strategies. This study aims to investigate the preoperative and intraoperative factors that may be associated with AKI in patients undergoing liver transplantation at the Princess Alexandra Hospital, Brisbane, Queensland. In our study, retrospective data of 97 consecutive orthotopic liver transplantations performed between January 2009 and August 2012 were recorded. Univariate and multivariate analyses were performed to investigate the preoperative and intraoperative risk factors for the development of AKI in this cohort. In the cohort of 97 patients who underwent orthotopic liver transplantation, 24 patients (25%) developed postoperative AKI. Univariate analysis demonstrated that high preoperative body mass index and intraoperative noradrenaline use were both associated with AKI. Multivariate analysis demonstrated that high body mass index, high Model for End-stage Liver Disease score and intraoperative noradrenaline use were associated with AKI. Overall mortaility was 4.1% during the study period and was not significantly different between the two groups. The high incidence of AKI following liver transplantation in this study cohort highlights the importance of this issue. This study has identified several potential pre- and intraoperative risk factors, providing a focus for patient surveillance and future research.

Intraoperative hemodynamics predict postoperative mortality in orthotopic liver transplantation

Liver transplantation remains the only curative treatment option for a variety of end-stage liver diseases. Prediction of major adverse events following surgery has traditionally focused on static predictors that are known prior to surgery. The effects of intraoperative management can now be explored due to the archiving of high-resolution monitoring data. We extracted intraoperative hemodynamic trend data of 55 patients undergoing orthotopic liver transplantation (OLT) and computed 12 features from the systolic arterial blood pressure (ABP), cardiac index, central venous pressure (CVP), and stroke volume variation (SVV) signals. Using a logistic regression classifier with a leave-one-out cross-validation procedure, we selected subsets of these features to predict mortality up to 180 days after surgery. Best performance was achieved with a combination of 3 features - median absolute deviation (MAD) of ABP, median CVP, and time spent with SVV <; 10% - reaching an area under the receiver-operating characteristic (or c-statistic) of 0.808. Odds ratios (OR) computed from the coefficients of the multivariate logistic regression model constructed from these features showed that greater time spent with SVV <; 10% (OR = 0.981 min(-1), p = 0.001) and greater MAD of systolic ABP (OR = 0.696 mmHg(-1), p = 0.026) were significantly associated with survival. Adding preoperative measures such as age and serum concentrations of albumin, bilirubin, and creatinine failed to improve performance of the prediction model. These results show that the course of intraoperative hemodynamics can predict 180-day mortality after OLT.

Incidence and Outcomes of Acute Renal Failure Following Liver Transplantation: A Population-Based Cohort Study

The aim of our large, population-based, cohort study was to explore the risk factors of acute renal failure (ARF) after liver transplant (LT) in Taiwan.From the Taiwanese National Health Insurance Research Database, 2862 patients who had undergone LT without pretransplant dialysis between July 1, 1998, and December 31, 2012, were identified. Preoperative, operative, and perioperative risks factors were considered and analyzed using logistic regression analysis, after adjusting for age and sex. All patients were followed up until the study endpoint or death.The final dataset included 214 patients with ARF and 2648 without ARF post-LT. Preoperative cerebrovascular diseases were the most important identifiable risk factor for ARF post-LT. Comparison of outcomes for patients "with" and "without" ARF indicated higher incidence rates of bacteremia, pneumonia, and postoperative bleeding, as well as longer stays in both intensive care unit and hospital. Kaplan-Meier mortality curves identified higher rates of mortality for patients' developing ARF at 1-year post-LT and overall at 14.5 years postsurgery.We provide evidence of a high incidence of ARF post-LT in Taiwan, with documented association of ARF with higher incidence rates of morbidity and mortality in this clinical population. The most important identifiable risk factor for ARF in our study was cerebrovascular diseases.

Disrupted Renal Mitochondrial Homeostasis after Liver Transplantation in Rats

BACKGROUND

Suppressed mitochondrial biogenesis (MB) contributes to acute kidney injury (AKI) after many insults. AKI occurs frequently after liver transplantation (LT) and increases mortality. This study investigated whether disrupted mitochondrial homeostasis plays a role in AKI after LT.

METHODS

Livers were explanted from Lewis rats and implanted after 18 h cold storage. Kidney and blood were collected 18 h after LT.

RESULTS

In the kidney, oxidative phosphorylation (OXPHOS) proteins ATP synthase-β and NADH dehydrogenase-3 decreased 44% and 81%, respectively, with marked reduction in associated mRNAs. Renal PGC-1α, the major regulator of MB, decreased 57% with lower mRNA and increased acetylation, indicating inhibited synthesis and suppressed activation. Mitochondrial transcription factor-A, which controls mtDNA replication and transcription, protein and mRNA decreased 66% and 68%, respectively, which was associated with 64% decreases in mtDNA. Mitochondrial fission proteins Drp-1 and Fis-1 and mitochondrial fusion protein mitofusin-1 all decreased markedly. In contrast, PTEN-induced putative kinase 1 and microtubule-associated protein 1A/1B-light chain 3 increased markedly after LT, indicating enhanced mitophagy. Concurrently, 18- and 13-fold increases in neutrophil gelatinase-associated lipocalin and cleaved caspase-3 occurred in renal tissue. Both serum creatinine and blood urea nitrogen increased >2 fold. Mild to moderate histological changes were observed in the kidney, including loss of brush border, vacuolization of tubular cells in the cortex, cast formation and necrosis in some proximal tubular cells. Finally, myeloperoxidase and ED-1 also increased, indicating inflammation.

CONCLUSION

Suppression of MB, inhibition of mitochondrial fission/fusion and enhancement of mitophagy occur in the kidneys of recipients of liver grafts after long cold storage, which may contribute to the occurrence of AKI and increased mortality after LT.

Acute kidney injury after liver transplantation: incidence and mortality

INTRODUCTION

Patients undergoing orthotopic liver transplantation often present with acute kidney injury (AKI) in the postoperative period. It has been associated with a greater number of complications and high mortality rates. The goal of this study was to determine the incidence of AKI during the early posttransplant period and mortality in patients undergoing orthotopic liver transplantation in our hospital.

PATIENTS AND METHODS

In this retrospective cohort study, we reviewed the medical records of all patients aged >18 years undergoing liver transplantation from April 2008 to April 2011. The exclusion criteria were a glomerular filtration rate (estimated by using the Modification of Diet in Renal Disease formula) <60 mL/min/1.73 m(2) or AKI at the time of transplantation. AKI was defined as an increase ≥50% from preoperative baseline serum creatinine levels during the hospitalization period.

RESULTS

Of 113 selected patients, 78 (69%) were male. The mean age was 54.03 ± 9.38 years. The mean preoperative baseline creatinine level was 0.94 ± 0.15 mg/dL, and the estimated glomerular filtration rate was 87.09 ± 19.67 mL/min/1.73 m(2). The mean calculated Model for End-Stage Liver Disease score was 13. Hepatitis C serology was present in 70.8%, hepatitis B in 11.5%, hepatocellular carcinoma in 75.2%, and alcohol abuse in 31.9% of patients. The incidence of AKI was 56.6% (64 of 113 patients). The main risk factors for AKI were Model for End-Stage Liver Disease score and diuretic use at baseline. Renal replacement therapy (RRT) was performed in 19.5% (22 of 113) of patients. The hospital mortality rate in the group with AKI was 25% (16 of 64 patients) and 6.1% (3 of 49 patients) between patients without AKI (odds ratio, 5.11 [confidence interval, 1.39-18.7]; P < .01]. Among patients who underwent RRT, the in-hospital mortality rate was 54.5% (12 of 22 patients) compared with 7.7% (7 of 91 patients) from the other remaining patient cohort (odds ratio, 14.40 [confidence interval, 4.60-45.00]; P < .01).

CONCLUSIONS

There was a high incidence of AKI in patients undergoing liver transplantation and an increased risk of mortality among patients who needed RRT.

Is there a relationship between intraoperative hemodynamic instability and calcineurin inhibitor-related toxicity, early after liver transplantation? A single-center observational study

This study evaluated the relationship between intraoperative hemodynamic instability (IOHI) and the development of calcineurin inhibitor (CNI) toxicity in the early postoperative period after liver transplantation (LT). Eighty-two patients were enrolled during a 1-year period and a 3-month follow-up. IOHI, requiring continuous infusion of vasopressors, was observed in 31 patients (38%, group 1; control group 2, n = 51). Acute kidney injury (AKI) developed in 28 patients (52% in group 1 vs 24% in group 2, P = .02), and CNI-related neurotoxicity (CNI-NT) in 26 (48% in group 1 vs 22% in group 2, P = .03). Group 1 patients received mainly deceased donor grafts (87% vs 57% in group 2, P < .001). An independent association between IOHI and CNI-NT (P = .029) and AKI (P = .016) was observed. The receiver-operator characteristic curve revealed an area under the curve of 0.63 for IHI (sensitivity 56%; specificity 75%) and 0.65 for AKI (sensitivity 56%; specificity 70.2%). In conclusion, patients undergoing LT with IOHI may be more prone to developing CNI-NT and AKI in the early postoperative period.

Comparison of RIFLE and AKIN criteria in the evaluation of the frequency of acute kidney injury in post-liver transplantation patients

BACKGROUND

Acute renal dysfunction is presented quite often after orthotopic liver transplantation (LT), with a reported incidence of 12-64%. The "RIFLE" criteria were introduced in 2004 for the definition of acute kidney injury (AKI) in critically ill patients, and a revised definition was proposed in 2007 by the Acute Kidney Injury Network (AKIN), introducing the AKIN criteria. The aim of this study was to record the incidence of AKI in patients after LT by both classifications and to evaluate their prognostic value on mortality.

METHODS

We retrospectively evaluated the records of patients with LT over 2 years (2011-2012) and recorded the incidence of AKI as defined by the RIFLE and AKIN criteria. Preoperative and admission severity of disease scores, duration of mechanical ventilation, intensive care unit length of stay, and 30- and 180-day survivals were also recorded.

RESULTS

Seventy-one patients were included, with an average age of 51.78 ± 10.3 years. The incidence of AKI according to the RIFLE criteria was 39.43% (Risk, 12.7%; Injury, 12.7%; Failure, 14.1%), whereas according to the AKIN criteria it was 52.1% (stage I, 22.5%; stage II, 7%; stage II 22.55%). AKI, regardless of the classification used, was related to the Model for End-Stage Liver Disease score, the volume of transfusions, the duration of mechanical ventilation, and survival. The presence of AKI was related to higher mortality, which rose proportionally with the severity of AKI as defined by the stages of either the RIFLE or the AKIN criteria.

CONCLUSIONS

AKI classifications according to the RIFLE and AKIN criteria are useful tools in the recognition and classification of the severity of renal dysfunction in patients after LT, because they are associated with higher mortality, which rises proportionally with the severity of renal disease.

Renal Function and Transplantation in Liver Disease

Kidney injury is associated with increased morbidity and mortality in liver transplant recipients. Since the introduction of the model for end-stage liver disease for the allocation of organs for liver transplantation in 2002, the heavy weighting of serum creatinine in the model for end-stage liver disease score has significantly increased the incidence of renal dysfunction seen among patients undergoing liver transplantation. As a result, the frequency of simultaneous liver-kidney (SLK) transplantation compared to liver transplantation alone (LTA) has also increased. The decision to perform SLK rather than LTA is an important one because the benefits to the liver transplant recipient receiving a kidney transplant must be balanced with the benefits of using that organ for a patient with end-stage renal disease. However, predicting whether or not a patient with liver failure has reversible kidney disease, and therefore does not also need a kidney transplant, is difficult. The severity and duration of pretransplant renal dysfunction, hepatitis c, diabetes, and other risk factors for kidney disease are associated with an increased risk of posttransplant end-stage renal disease. However, there are currently no clinical findings that accurately predict renal recovery post liver transplant. As a result, the rate of SLK versus LTA differs significantly between transplant centers. To increase consistency across centers, multiple guidelines have been proposed to guide the decision between SLK and LTA, but their poor predictive value has limited their uniform adoption. Nevertheless, adoption of uniform rules for the allocation of kidneys would reduce the variability between centers in rates of SLK transplant.

Clinical Risk Scoring Models for Prediction of Acute Kidney Injury after Living Donor Liver Transplantation: A Retrospective Observational Study

Acute kidney injury (AKI) is a frequent complication of liver transplantation and is associated with increased mortality. We identified the incidence and modifiable risk factors for AKI after living-donor liver transplantation (LDLT) and constructed risk scoring models for AKI prediction. We retrospectively reviewed 538 cases of LDLT. Multivariate logistic regression analysis was used to evaluate risk factors for the prediction of AKI as defined by the RIFLE criteria (RIFLE = risk, injury, failure, loss, end stage). Three risk scoring models were developed in the retrospective cohort by including all variables that were significant in univariate analysis, or variables that were significant in multivariate analysis by backward or forward stepwise variable selection. The risk models were validated by way of cross-validation. The incidence of AKI was 27.3% (147/538) and 6.3% (34/538) required postoperative renal replacement therapy. Independent risk factors for AKI by multivariate analysis of forward stepwise variable selection included: body-mass index >27.5 kg/m2 [odds ratio (OR) 2.46, 95% confidence interval (CI) 1.32-4.55], serum albumin <3.5 mg/dl (OR 1.76, 95%CI 1.05-2.94), MELD (model for end-stage liver disease) score >20 (OR 2.01, 95%CI 1.17-3.44), operation time >600 min (OR 1.81, 95%CI 1.07-3.06), warm ischemic time >40 min (OR 2.61, 95%CI 1.55-4.38), postreperfusion syndrome (OR 2.96, 95%CI 1.55-4.38), mean blood glucose during the day of surgery >150 mg/dl (OR 1.66, 95%CI 1.01-2.70), cryoprecipitate > 6 units (OR 4.96, 95%CI 2.84-8.64), blood loss/body weight >60 ml/kg (OR 4.05, 95%CI 2.28-7.21), and calcineurin inhibitor use without combined mycophenolate mofetil (OR 1.87, 95%CI 1.14-3.06). Our risk models performed better than did a previously reported score by Utsumi et al. in our study cohort. Doses of calcineurin inhibitor should be reduced by combined use of mycophenolate mofetil to decrease postoperative AKI. Prospective randomized trials are required to address whether artificial modification of hypoalbuminemia, hyperglycemia and postreperfusion syndrome would decrease postoperative AKI in LDLT.

Low dose albumin for the prevention of renal impairment following large volume paracentesis in cirrhosis

OBJECTIVES

To evaluate the effect of low dose Albumin i.e. 4 grams per litre of ascitic fluid after large volume paracentesis (LVP) for the prevention of paracentesis induced circulatory dysfunction (PICD) related renal impairment in cirrhosis.

METHODS

Case records of all patients with cirrhosis who underwent LVP from January 12(th), 2011 till December 29(th), 2013 were reviewed. Patients were excluded if they had spontaneous bacterial peritonitis, creatinine >1.5 mg/dl, hepatoma or if volume of ascitic fluid removed was <5 litres. Data including age, gender, cause of cirrhosis, CTP score and volume of ascitic fluid drained were noted. In addition serum creatinine and serum sodium at baseline and one week post paracentesis were recorded.

RESULTS

Two hundred and fourteen patients with cirrhosis underwent LVP during the study period. One hundred and thirty nine patients met the inclusion criteria and were analyzed. Patients were divided into two groups based on the amount of albumin given. The amount of albumin given was 25 grams and 50 grams while the volume of ascitic fluid removed were 6.2±1 litres and 10.4±1.5 litres in groups A and B respectively. One hundred and eight patients were in group A while thirty one patients were in group B respectively. Both groups received albumin at a dose of 4 grams per litre of ascitic fluid removed. Mean age in both groups were 53 years. Hepatitis C was the commonest etiology in both the groups, followed by Hepatitis B. More than 70% patients in both the groups were in child class C. Serum creatinine at baseline and one week post LVP was 1.04±0.24 mg/dl and 1.07±0.35 mg/dl in GROUP A while 1.11±0.23 mg/dl and 1.41±0.94 mg/dl in GROUP B. (P value 0.35). Similarly, serum sodium at baseline and one week post LVP was 130 ±5.6 meq/lit and 129.6±5.9 meq/lit in GROUP A while 127.6±5.8 meq/lit and 128±6.2 meq/lit in GROUP B respectively. (P value 0.14).

CONCLUSION

This study suggests that 4 grams of albumin per litre of ascitic fluid drained is effective in preventing the PICD related renal impairment following large volume paracentesis in cirrhosis.

Prospective Randomized Trial Comparing Hepatic Venous Outflow and Renal Function after Conventional versus Piggyback Liver Transplantation

BACKGROUND

This randomized prospective clinical trial compared the hepatic venous outflow drainage and renal function after conventional with venovenous bypass (n = 15) or piggyback (n = 17) liver transplantation.

METHODS

Free hepatic vein pressure (FHVP) and central venous pressure (CVP) measurements were performed after graft reperfusion. Postoperative serum creatinine (Cr) was measured daily on the first week and on the 14th, 21st and 28th postoperative days (PO). The prevalence of acute renal failure (ARF) up to the 28th PO was analyzed by RIFLE-AKIN criteria. A Generalized Estimating Equation (GEE) approach was used for comparison of longitudinal measurements of renal function.

RESULTS

FHVP-CVP gradient > 3 mm Hg was observed in 26.7% (4/15) of the patients in the conventional group and in 17.6% (3/17) in the piggyback group (p = 0.68). Median FHVP-CVP gradient was 2 mm Hg (0-8 mmHg) vs. 3 mm Hg (0-7 mm Hg) in conventional and piggyback groups, respectively (p = 0.73). There is no statistically significant difference between the conventional (1/15) and the piggyback (2/17) groups regarding massive ascites development (p = 1.00). GEE estimated marginal mean for Cr was significantly higher in conventional than in piggyback group (2.14 ± 0.26 vs. 1.47 ± 0.15 mg/dL; p = 0.02). The conventional method presented a higher prevalence of severe ARF during the first 28 PO days (OR = 3.207; 95% CI, 1.010 to 10.179; p = 0.048).

CONCLUSION

Patients submitted to liver transplantation using conventional or piggyback methods present similar results regarding venous outflow drainage of the graft. Conventional with venovenous bypass technique significantly increases the harm of postoperative renal dysfunction.

TRIAL REGISTRATION

ClinicalTrials.gov https://clinicaltrials.gov/ct2/show/NCT01707810.

Macrophage migration inhibitory factor as a potential predictor for requirement of renal replacement therapy after orthotopic liver transplantation

Acute kidney injury (AKI) after orthotopic liver transplantation (OLT) is associated with a poor clinical outcome. Because there is no specific treatment for postoperative AKI, early recognition and prevention are fundamental therapeutic approaches. Concentrations of the proinflammatory cytokine macrophage migration inhibitory factor (MIF) are elevated in patients with kidney disease. We hypothesized that plasma MIF concentrations would be greater in patients developing AKI after OLT compared with patients with normal kidney function. Twenty-eight patients undergoing OLT were included in the study. Kidney injury was classified according to AKI network criteria. Fifteen patients (54%) developed severe AKI after OLT, 11 (39%) requiring renal replacement therapy (RRT). On the first postoperative day, patients with severe AKI had greater plasma MIF concentrations (237 ± 123 ng/mL) than patients without AKI (95 ± 63 ng/mL; P < 0.001). The area under the receiver operating characteristic (ROC) curve for predicting severe AKI was 0.87 [95% confidence interval (CI), 0.69-0.97] for plasma MIF, 0.61 (95% CI, 0.40-0.79) for serum creatinine (sCr), and 0.90 (95% CI, 0.72-0.98) for delta serum creatinine (ΔsCr). Plasma MIF (P = 0.02) and ΔsCr (P = 0.01) yielded a better predictive value than sCr for the development of severe AKI. Furthermore, the area under the ROC curve to predict the requirement of RRT was 0.87 (95% CI, 0.68-0.96) for plasma MIF, 0.65 (95% CI, 0.44-0.82) for sCr, and 0.72 (95% CI, 0.52-0.88) for ΔsCr. Plasma MIF had a better predictive value than sCr for the requirement of RRT (P = 0.02). In conclusion, postoperative plasma MIF concentrations were elevated in patients who developed severe AKI after OLT. Furthermore, plasma MIF concentrations showed a good prognostic value for identifying patients developing severe AKI or requiring postoperative RRT after OLT.

Outcomes Using Grafts from Donors after Cardiac Death

BACKGROUND

Previous reports suggest that donation after cardiac death (DCD) liver grafts have increased primary nonfunction (PNF) and cholangiopathy thought to be due to the graft warm ischemia before cold flushing.

STUDY DESIGN

In this single-center, retrospective study, 866 adult liver transplantations were performed at our institution from January 2005 to August 2014. Forty-nine (5.7%) patients received DCD donor grafts. The 49 DCD graft recipients were compared with all recipients of donation after brain death donor (DBD) grafts and to a donor and recipient age- and size-matched cohort.

RESULTS

The DCD donors were younger (age 28, range 8 to 60 years) than non-DCD (age 44.3, range 9 to 80 years) (p < 0.0001), with similar recipient age. The mean laboratory Model for End-Stage Liver Disease (MELD) was lower in DCD recipients (18.7 vs 22.2, p = 0.03). Mean cold and warm ischemia times were similar. Median ICU and hospital stay were 2 days and 7.5 days in both groups (p = 0.37). Median follow-ups were 4.0 and 3.4 years, respectively. Long-term outcomes were similar between groups, with similar 1-, 3- and 5-year patient and graft survivals (p = 0.59). Four (8.5%) recipients developed ischemic cholangiopathy (IC) at 2, 3, 6, and 8 months. Primary nonfunction and hepatic artery thrombosis did not occur in any patient in the DCD group. Acute kidney injury was more common with DCD grafts (16.3% of DCD recipients required dialysis vs 4.1% of DBD recipients, p = 0.01). An increased donor age (>40 years) was shown to increase the risk of IC (p = 0.006).

CONCLUSIONS

Careful selection of DCD donors can provide suitable donors, with results of liver transplantation comparable to those with standard brain dead donors.

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.

Renal function status in liver transplant patients in the first month post-transplant is associated with progressive chronic kidney disease

AIM

Renal dysfunction is a common complication of liver transplantation (LT), related to hepatorenal syndrome with end-stage liver disease or calcineurin-inhibitor nephrotoxicity. Chronic kidney disease (CKD) is also a common problem in long-term survivors post-LT. This study was done to investigate the association between renal functional status soon after LT and the development of CKD.

METHODS

We retrospectively evaluated 63 patients who were aged 18 years or older, and underwent LT at Tohoku University Hospital. The estimated glomerular filtration rate (eGFR) was calculated by the Modification of Diet in Renal Disease study equation for Japan.

RESULTS

Before transplantation, 25 patients (39.7%) were diagnosed with CKD (eGFR, <60 mL/min per 1.73 m(2) ). The incidence of CKD was 22.4% (13/58) at 2 years, 23.2% (13/56) at 3 years and 22.7% (12/54) at 5 years. The patients with CKD at 2 years post-transplant were more likely to have a history of glomerulonephritis, and were significantly older at the time of LT, compared to those without CKD. Levels of eGFR of less than 60 mL/min per 1.73 m(2) in the first month post-transplant and a volume of intraoperative blood loss of more than 300 mL/kg were predictive factors for the development of CKD at 2 years post-transplant and thereafter.

CONCLUSION

We have shown that there is an improvement of renal function in the majority of patients after LT. Regardless of the presence of pre-existing CKD, both renal function status at the first month post-transplant and a volume of intraoperative blood loss were predictive factors for the development of CKD at 2 years post-transplant and thereafter.

Intravenous fenoldopam for early acute kidney injury after liver transplantation

PURPOSE

Acute kidney injury remains a serious complication after orthotopic liver transplantation. To date, several 'renal-protective' agents have been explored in this setting but with conflicting and disappointing results. Therefore, our aim is to evaluate the effects of fenoldopam in liver transplant patients with an established renal injury.

METHODS

In this prospective study, intravenous fenoldopam 0.1 µg/kg/min was administered to consecutive liver transplant patients with postoperative (within 7 days from surgery) stage 2 acute kidney injury (AKI) according to the Acute Kidney Injury Network classification. Actual glomerular filtration rate (GFR; calculated by the iohexol plasma clearance), serum creatinine (SCr) and cystatin C (SCyC) were used to assess the effect of the medication on the patients.

RESULTS

During the study, 295 patients underwent liver transplant. Fifty-one patients (17.6%) met the inclusion criteria and the data from 48 patients were analysed. SCr and SCyC levels decreased (p < 0.001 after 48 h; p < 0.0001 after 72 h) and GFR increased (p < 0.001 after 24 h; p < 0.0001 after 72 h). When compared to a cohort of comparable patients with AKI from our historical series, the patients in the present study showed better SCr and SCyC levels. It was not necessary to discontinue the infusion of fenoldopam in any patient because of the occurrence of adverse events potentially attributable to it.

CONCLUSION

We showed that fenoldopam was capable of improving some renal function parameters in postoperative liver transplantation patients with on-going AKI. This preliminary study now sets the stage for a multicenter, randomized, placebo-controlled trial in order to provide definite evidence.

Chloride-liberal fluids are associated with acute kidney injury after liver transplantation

INTRODUCTION

Acute kidney injury (AKI) occurs frequently after liver transplantation and is associated with significant morbidity and mortality. Recent evidence has linked the predominant usage of 'chloride-liberal' intravenous fluids, such as 0.9% saline to the development of renal dysfunction in general critically ill patients. We compared the effects of perioperative fluid types on AKI in liver transplant recipients.

METHODS

An observational analysis of liver transplant recipients over a 33-month period, between January 2010 and September 2013, was performed. Intensive care unit database and patient records were analyzed for determinants of early postoperative AKI. Univariate and multivariate regression analysis was carried out using a two-tailed P value less than 0.05 to establish significance. The institutional Research Ethics Committee approved the study methodology (RAC no. 2131 073).

RESULTS

One hundred and fifty-eight liver transplants were performed, AKI developed in 57 (36.1%) patients: 39 (68.4%) fully recovered, 13 (22.8%) developed chronic renal failure and 10 (17.5%) required long-term hemodialysis. On univariate regression analysis, AKI was significantly associated with greater than 3,200 ml of chloride-liberal fluids infused within the first postoperative day (HR 5.9, 95% CI 2.64, 13.2, P < 0.001), greater than 1,500 ml colloids received in the operating room (hazard ratio (HR) 1.97, 95% CI 1.01, 3.8, P = 0.046), vasopressor requirement for 48 hours posttransplant (HR 3.34, 95% CI 1.55, 7.21, P = 0.002), hyperchloremia at day 2 (HR 1.09, 95% CI 1.01, 1.18, P = 0.015) and preoperative model for end-stage liver disease (MELD) score (HR 1.08, 95% CI 1.03, 1.13, P < 0.001). After stepwise multivariate regression, infusion of greater than 3,200 ml of chloride-liberal fluids (HR 6.25, 95% CI 2.69, 14.5, P < 0.000) and preoperative MELD score (HR 1.08, 95% CI 1.02, 1.15, P = 0.004) remained significant predictors for AKI.

CONCLUSIONS

In a sample of liver transplant recipients, infusion of higher volumes of chloride-liberal fluids and preoperative status was associated with an increased risk for postoperative AKI.

Urinary neutrophil gelatinase-associated lipocalin: a useful biomarker for tacrolimus-induced acute kidney injury in liver transplant patients

Tacrolimus is widely used as an immunosuppressant in liver transplantation, and tacrolimus-induced acute kidney injury (AKI) is a serious complication of liver transplantation. For early detection of AKI, various urinary biomarkers such as monocyte chemotactic protein-1, liver-type fatty acid-binding protein, interleukin-18, osteopontin, cystatin C, clusterin and neutrophil gelatinase-associated lipocalin (NGAL) have been identified. Here, we attempt to identify urinary biomarkers for the early detection of tacrolimus-induced AKI in liver transplant patients. Urine samples were collected from 31 patients after living-donor liver transplantation (LDLT). Twenty recipients developed tacrolimus-induced AKI. After the initiation of tacrolimus therapy, urine samples were collected on postoperative days 7, 14, and 21. In patients who experienced AKI during postoperative day 21, additional spot urine samples were collected on postoperative days 28, 35, 42, 49, and 58. The 8 healthy volunteers, whose renal and liver functions were normal, were asked to collect their blood and spot urine samples. The urinary levels of NGAL, monocyte chemotactic protein-1 and liver-type fatty acid-binding protein were significantly higher in patients with AKI than in those without, while those of interleukin-18, osteopontin, cystatin C and clusterin did not differ between the 2 groups. The area under the receiver operating characteristics curve of urinary NGAL was 0.876 (95% confidence interval, 0.800–0.951; P<0.0001), which was better than those of the other six urinary biomarkers. In addition, the urinary levels of NGAL at postoperative day 1 (p = 0.0446) and day 7 (p = 0.0006) can be a good predictive marker for tacrolimus-induced AKI within next 6 days, respectively. In conclusion, urinary NGAL is a sensitive biomarker for tacrolimus-induced AKI, and may help predict renal event caused by tacrolimus therapy in liver transplant patients.

Netrin-1 and semaphorin 3A predict the development of acute kidney injury in liver transplant patients

Acute kidney injury (AKI) is a serious complication after liver transplantation. Currently there are no validated biomarkers available for early diagnosis of AKI. The current study was carried out to determine the usefulness of the recently identified biomarkers netrin-1 and semaphorin 3A in predicting AKI in liver transplant patients. A total of 63 patients’ samples were collected and analyzed. AKI was detected at 48 hours after liver transplantation using serum creatinine as a marker. In contrast, urine netrin-1 (897.8±112.4 pg/mg creatinine), semaphorin 3A (847.9±93.3 pg/mg creatinine) and NGAL (2172.2±378.1 ng/mg creatinine) levels were increased significantly and peaked at 2 hours after liver transplantation but were no longer significantly elevated at 6 hours after transplantation. The predictive power of netrin-1, as demonstrated by the area under the receiver-operating characteristic curve for diagnosis of AKI at 2, 6, and 24 hours after liver transplantation was 0.66, 0.57 and 0.59, respectively. The area under the curve for diagnosis of AKI was 0.63 and 0.65 for semaphorin 3A and NGAL at 2 hr respectively. Combined analysis of two or more biomarkers for simultaneous occurrence in urine did not improve the AUC for the prediction of AKI whereas the AUC was improved significantly (0.732) only when at least 1 of the 3 biomarkers in urine was positive for predicting AKI. Adjusting for BMI, all three biomarkers at 2 hours remained independent predictors of AKI with an odds ratio of 1.003 (95% confidence interval: 1.000 to 1.006; P = 0.0364). These studies demonstrate that semaphorin 3A and netrin-1 can be useful early diagnostic biomarkers of AKI after liver transplantation.

Risk factors of acute renal failure after orthotopic liver transplantation: single-center experience

BACKGROUND

Acute renal failure (ARF) is one of the most significant complications of orthotopic liver transplantation (OLT), associated with increased mortality rate and the development of chronic renal dysfunction. The aim of the study was to determine the perioperative risk factors for ARF in patients without previous history of renal disease who are undergoing OLT.

MATERIALS AND METHODS

Forty-six patients who developed ARF after OLT performed in 1 transplant center were included in the study, and 52 consecutive patients without that complication served as a control group. Renal dysfunction was defined as a glomerular filtration rate <60 mL/min/1.73 m(2). The data concerning preoperative diseases, perioperative renal function, first-line immunosuppressive therapy, and blood transfusion requirement were retrospectively analyzed and compared among groups. Logistic regression modeling was used to determine risk factors for ARF.

RESULTS

Patients who developed ARF were significantly older (mean age 53.3 vs 46.3 years, P = .057), had higher level of preoperative (0.79 vs 0.71 mg/dL, P = .0062) and intraoperative (0.85 vs 0.74 mg/dL, P = .0045) creatinine. The risk factors for ARF were intraoperative and 24-hour post-transplant creatinine level >0.9 mg/dL and high-dose tacrolimus-based immunosuppression. Transfusion of ≤6 units of red blood cells diminished the risk of ARF. Sex and preoperative diseases were not predictive to ARF in our regression models.

CONCLUSION

Careful operative technique with low blood loss and immunosuppressive therapy of low nephrotoxic potential should be recommended in older patients to diminish the risk of renal dysfunction after orthotopic liver transplantation. Patients with higher levels of perioperative creatinine should be considered to have first-line immunosuppression without calcineurin inhibitors or with low-dose immunosuppressants of known nephrotoxic potential.

Renal dysfunction in end-stage liver disease and post-liver transplant

Renal dysfunction is a frequent complication in patients with end-stage liver disease awaiting orthotopic liver transplantation and in the post-liver transplant period. Although the stereotypical form of renal dysfunction is the hepatorenal syndrome, other causes of acute kidney injury in this population include prerenal azotemia and acute tubular necrosis. Renal injury in a patient with cirrhosis is associated with a poor prognosis.

A meta-analysis of complications following deceased donor liver transplant

BACKGROUND

Liver transplantation is a complex surgery associated with high rates of postoperative complications. While national outcomes data are available, national rates of most complications are unknown.

DATA SOURCES

A systematic review of the literature reporting rates of postoperative complications between 2002 and 2012 was performed. A cohort of 29,227 deceased donor liver transplant recipients from 74 studies was used to calculate pooled incidences for 17 major postoperative complications.

CONCLUSIONS

This is the first comprehensive review of postoperative complications after liver transplantation and can serve as a guide for transplant and nontransplant clinicians. Efforts to collect national data on complications, such as through the National Surgical Quality Improvement Program, would improve the ability to provide patients with informed consent, serve as a tool for individual center performance monitoring, and provide a central source against which to measure interventions aimed at improving patient care.

Intraoperative fluid and pharmacologic management and the anesthesiologist's supervisory role for nontraditional technologies during liver transplantation: a survey of US academic centers

BACKGROUND

Volume resuscitation and use of vasoactive medications during liver transplantation has not been systematically assessed. Furthermore, the anesthesiologist's role for intraoperative oversight of technologies such as renal replacement therapy and procedures such as venovenous bypass is poorly defined, and it is unclear if the center's annual transplant frequency affects these practices.

METHODS

We conducted a database analysis of the Liver Transplant Anesthesia Consortium survey 202 that addresses these questions. Data from US academic liver transplant anesthesia programs meeting inclusion criteria were included. Results were categorized by their annual transplant volume.

RESULTS

A representative sample of 66% of all eligible centers contributed to the results. Normal saline among crystalloids and albumin among colloids were the most frequently chosen maintenance and non-blood product volume expansion fluids, with little variation by center size. A large variety of vasoactive agents is routinely utilized across programs, with vasopressors as a cornerstone of hemodynamic support. Large programs seem to use less of these agents compared with lower volume centers.

CONCLUSION

Anesthesiologists are increasingly involved in oversight and management of intraoperative renal replacement therapies, venovenous bypass and cell saver devices with rising transplant frequency. This new insight may be indicative of skill sets needed by members of liver transplantation anesthesia teams and should be considered in curriculum design for hepatobiliary transplant anesthesia fellowships.

Risk factors for acute renal injury in living donor liver transplantation: evaluation of the RIFLE criteria

Acute renal injury (ARI) is a serious complication after liver transplantation. This study investigated the usefulness of the RIFLE criteria in living donor liver transplantation (LDLT) and the prognostic impact of ARI after LDLT. We analyzed 200 consecutive adult LDLT patients, categorized as risk (R), injury (I), or failure (F), according to the RIFLE criteria. ARI occurred in 60.5% of patients: R-class, 23.5%; I-class, 21%; and F-class, 16%. Four patients in Group-A (normal renal function and R-class) and 26 patients in Group-B (severe ARI: I- and F-class) required renal replacement therapy (P < 0.001). Mild ARI did not affect postoperative prognosis regarding hospital mortality rate in Group A (3.2%), which was superior to that in Group B (15.8%; P = 0.0015). Fourteen patients in Group B developed chronic kidney disease (KDIGO stage 3/4). The 1-, 5- and 10-year survival rates were 96.7%, 90.6%, and 88.1% for Group A and 71.1%, 65.9%, and 59.3% for Group B, respectively (P < 0.0001). Multivariate analysis revealed risk factors for severe ARI as MELD ≥ 20 [odds ratio (OR) 2.9], small-for-size graft (GW/RBW <0.7%; OR 3.1), blood loss/body weight >55 ml/kg (OR 3.7), overexposure to calcineurin inhibitor (OR 2.5), and preoperative diabetes mellitus (OR 3.2). The RIFLE criteria offer a useful predictive tool after LDLT. Severe ARI, defined beyond class-I, could have negative prognostic impact in the acute and late postoperative phases. Perioperative treatment strategies should be designed and balanced based on the risk factors for the further improvement of transplant prognosis.

Incidence, predictive factors, and clinical outcomes of acute kidney injury after gastric surgery for gastric cancer

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 short-term mortality.

Acute renal failure in liver transplant patients: Indian study

The acute renal failure is the frequent medical complication observed in liver transplant patients. The objective of this study was to determine the cause of acute renal failure in post liver transplant patients. A total of 70 patients who underwent (cadaveric 52, live 18) liver transplantation were categorized based on clinical presentation into two groups, namely hepatorenal failure (HRF, n = 29), and Hepatic failure (HF, n = 41). All the patients after the liver transplant had received tacrolimus, mycophenolate and steroids. We analyzed the modification of diet in renal disease, (MDRD) serum urea, creatinine and albumin before and after 5th and 30th day of liver transplant and data was categorized into survivors and non-survivors group. In HRF survivor group, serum creatinine, and urea levels were high and, albumin, MDRD were low in pre- transplant and reached to normal levels on 30th day of post transplant, and 79.3 % of patients in this group showed resumption of normal kidney function. On the contrary in HRF nonsurvivor group, we did not observed any significant difference and 20.7 % of patients showed irreversible changes after the liver transplant. In HF survivor group, 82.9 % of liver failure patients did not show any deviation in serum creatinine, urea, albumin and MDRD, whereas in HF non survivor group, 17.1 % of liver failure patients who had HCV positive before the transplant developed acute renal failure. The levels of creatinine, urea, albumin and MDRD were normal before the transplant and on day 30th, the levels of albumin and MDRD were significantly low whereas serum urea, creatinine levels were high. In conclusion, based on these observations, an diagnosis and treatment of Acute renal failure is important among the liver transplantation cases in the early postoperative period.

Hepatic ischemia reperfusion injury is associated with acute kidney injury following donation after brain death liver transplantation

Donation after cardiac death liver transplant recipients have an increased frequency of acute kidney injury (AKI). This suggests that hepatic ischemia-reperfusion injury may play a critical role in the pathogenesis of AKI after liver transplantation. The aim of this single-center study was to determine if hepatic ischemia-reperfusion injury, estimated by peak peri-operative serum amino-transferase (AST), is associated with AKI following donation after brain death (DBD) liver transplantation. A total of 296 patients received 298 DBD liver transplants from January 2007 to June 2011. The incidence of AKI was 35.9%. AKI was a risk factor for chronic kidney disease (P = 0.037) and mortality (P = 0.002). On univariate analysis, peak AST correlated with peak creatinine (P < 0.001) and peak change in creatinine from baseline (P < 0.001). Peak AST was higher in AKI patients (P < 0.001). The incidence of AKI in patients with a peak AST of <1500, 1500-2999 and ≥ 3000 U/l was 26.1%, 39.8% and 71.2%, respectively (P < 0.001). On multiple logistic regression analysis, peak AST was independently associated with the development of AKI (P < 0.001). In conclusion, hepatic ischemia-reperfusion injury demonstrates a strong relationship with peri-operative AKI in DBD liver transplant recipients.

The effects of intraoperative cryoprecipitate transfusion on acute renal failure following orthotropic liver transplantation

Purpose

The definition of risk factors associated with acute renal failure (ARF) following orthotropic liver transplantation (OLT) is still controversial. Cryoprecipitate, which can supply fibrinogen and other coagulation factors, is widely used in OLT. However, the effects of intraoperative cryoprecipitate transfusion on ARF following OLT remain unclear.

Methods

In a series of 389 adult patients who received grafts from deceased donors and underwent their first OLT, the clinical correlation between intraoperative cryoprecipitate transfusion and ARF following OLT was retrospectively studied after adjusting for potential confounders. The distribution of ARF and the causes of death within the first year after OLT were also compared separately in patients with and without cryoprecipitate transfusion.

Results

The incidence of ARF in patients with cryoprecipitate transfusion was significantly higher than in patients without cryoprecipitate transfusion (15.9 vs. 7.8 %, p = 0.012). A nonlinear relationship between intraoperative cryoprecipitate transfusion and ARF following OLT was observed. The risk of ARF increased with the cryoprecipitate transfusion level up to the turning point (16 U) (adjusted OR 1.1, 95 % CI 1.1–1.2; p < 0.001). When the cryoprecipitate level exceeded 16 U, the level of cryoprecipitate transfusion was not associated with the risk of ARF (OR 0.95, 95 % CI 0.85–1.1; p = 0.319). Deaths within the first year after the operation occurred more frequently in cases with cryoprecipitate transfusion (22.9 vs. 14.2 %, p = 0.029).

Conclusions

These findings suggested that intraoperative cryoprecipitate transfusion is associated with ARF following OLT. Cryoprecipitate transfusion during OLT should be performed carefully until more convincing evidence has been found.

Predictors of renal recovery in patients with pre-orthotopic liver transplant (OLT) renal dysfunction

BACKGROUND

Renal dysfunction occurs commonly in patients awaiting orthotopic liver transplantation (OLT) for end-stage liver disease. The use of simultaneous liver-kidney transplantation has increased in the MELD scoring era. As patients may recover renal function after OLT, identifying factors predictive of renal recovery is a critical issue, especially given the scarcity of available organs.

METHODS

Employing the UNOS database, we sought to identify donor- and patient-related predictors of renal recovery among 1720 patients with pre-OLT renal dysfunction and transplanted from 1989 to 2005. Recovery of renal function post-OLT was defined as a composite endpoint of serum creatinine (SCr) ≤1.5 mg/dL at discharge and survival ≥29 days. Pre-OLT renal dysfunction was defined as any of the following: SCr ≥2 mg/dL at any time while awaiting OLT or need for renal replacement therapy (RRT) at the time of registration and/or OLT.

RESULTS

Independent predictors of recovery of renal function post-OLT were absence of hepatic allograft dysfunction, transplantation during MELD era, recipient female sex, decreased donor age, decreased recipient ALT at time of OLT, decreased recipient body mass index at registration, use of anti-thymocyte globulin as induction therapy, and longer wait time from registration. Contrary to popular belief, a requirement for RRT, even for prolonged periods in excess of 8 weeks, was not an independent predictor of failure to recover renal function post-OLT.

CONCLUSION

These data indicate that the duration of renal dysfunction, even among those requiring RRT, is a poor way to discriminate reversible from irreversible renal dysfunction.

Postoperative kidney injury does not decrease survival after liver transplantation

PURPOSE

To explore the effect of acute kidney injury (AKI) on long-term survival after conventional orthotopic liver transplantation (OLT) without venovenous bypass (VVB).

METHODS

A retrospective cohort study was carried out on 153 patients with end-stage liver diseases transplanted by the Department of General Surgery and Liver Transplantation of the University of Pernambuco, from August, 1999 to December, 2009. The Kaplan-Meier survival estimates and log-rank test were applied to explore the association between AKI and long-term patient survival, and multivariate analyses were applied to control the effect of other variables.

RESULTS

Over the 12.8-year follow-up, 58.8% patients were alive with a median follow-up of 4.5-year. Patient 1-, 2-, 3- and 5-year survival were 74.5%, 70.6%, 67.9% and 60.1%; respectively. Early postoperative mortality was poorer amongst patients who developed AKI (5.4% vs. 20%, p=0.010), but long-term 5-year survival did not significantly differed between groups (51.4% vs. 65.3%; p=0.077). After multivariate analyses, AKI was not significantly related to long-term survival and only the intraoperative transfusion of red blood cells was significantly related to this outcome (non-adjusted Exp[b]=1.072; p=0.045).

CONCLUSION

The occurrence of postoperative acute kidney injury did not independently decrease patient survival after orthotopic liver transplantation without venovenous bypass in this data from northeast Brazil.

Intrarenal resistance index for the assessment of acute renal injury in a rat liver transplantation model

Background

Acute kidney injury (AKI) is a common complication after liver transplantation (LT) and associated with a high mortality. The renal resistive index (RI) is used to assess early renal function impairment in critical care patients. However, limited data are available concerning changes of renal RI and the development of AKI early after reperfusion. We approached to investigate the changes of renal RI and AKI after reperfusion in a rat liver transplantation model.

Methods

Rats were randomly divided into sham group or LT group. Ten rats in each group were used for the hemodynamic study and twenty for Doppler measurements during the procedure. Ten rats were sacrificed 30 min or 2 h after the reperfusion. We harvested kidneys, serum and urine for further analysis of the renal function.

Results

The intrarenal RI increased significantly in the anhepatic stage and decreased significantly after the reperfusion in the LT group compared with sham group (P < 0.05). AKI was seen after the reperfusion in the LT group. No correlation was noted between the RI and renal function parameters 30 min after reperfusion.

Conclusions

The intrarenal RI increased significantly during the anhepatic stage, and decreased significantly early after the reperfusion. Intrarenal RI was unable to assess renal function in a rat liver transplantation model.

Urine IL-18, NGAL, IL-8 and serum IL-8 are biomarkers of acute kidney injury following liver transplantation

BACKGROUND

AKI is common following liver transplantation and is associated with significant morbidity and mortality. Biomarkers of AKI have not been well established in this setting but are needed to help guide patient care and facilitate development of novel therapeutics.

METHODS

Serum creatinine, cystatin C, IL-6, and IL-8 and urine IL-18, NGAL, IL-6, and IL-8 were measured before and within 24 hours after liver transplantation in 40 patients. AKI was defined as a ≥50% sustained increase in creatinine above pre-operative values occurring within 24 hours of transplantation and persisting for at least 24 hours.

RESULTS

Seven patients met criteria for AKI (17.5%), with mean creatinines of 0.81 mg/dL pre-operatively and 1.75 mg/dL post-operatively. While pre-operative biomarker levels in patients with AKI were similar to those in patients without AKI, differences were seen between the groups with regard to median post-operative serum IL-8 (pg/mL) (242.48 vs. 82.37, p = 0.0463) and urine NGAL (ng/mL) (386.86 vs. 24.31, p = 0.0039), IL-6 (pg/mL) (52 vs. 7.29, p=0.0532), IL-8 (pg/mL) (14.3 vs. 0, p = 0.0224), and IL-18 (pg/mL) (883.09 vs. 0, p = 0.0449). The areas under receiver operating characteristic (ROC) curves were 0.749 for urine IL-18, 0.833 for urine NGAL, 0.745 for urine IL-6, 0.682 for serum IL-6, 0.773 for urine IL-8, and 0.742 for serum IL-8. Post-operative cystatin C was not significantly different between AKI and no AKI groups.

CONCLUSION

Serum IL-8 and urine IL-18, NGAL, IL-6, and IL-8 are elevated in AKI within the first 24 hours following liver transplantation.

Perioperative acute kidney injury

The incidence of acute kidney injury (AKI) is generally 5-7.5% in all acute care hospitalizations and accounts for up to 20% of admissions to intensive care units (ICUs). Of all of the cases of AKI during hospitalization, approximately 30-40% are observed in operative settings. AKI is a serious morbidity that is associated with greater length of hospital stay, high risk of hospital mortality, and increased risk of incident and progressive chronic kidney disease. The incidence of AKI is variable depending on the specific surgical setting under consideration. Much of our knowledge regarding the epidemiology of AKI is derived from studies related to cardiac or vascular surgery. With limited treatment options, prevention of AKI and amelioration of its severity remain important cornerstones of improving patient outcomes. The magnitude of the problem and the unique set of patient characteristics calls for a multidisciplinary approach for the perioperative management of renal complications. The purpose of the review presented here is to discuss the current knowledge regarding the epidemiology and risk factors, outcomes, diagnoses, and prevention and treatment of AKI during the perioperative period in cardiovascular and noncardiovascular surgical settings.