Risk factors for renal dysfunction in the postoperative course of liver transplant

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.

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.

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.

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.

Restrictive and liberal red cell transfusion strategies in adult patients: reconciling clinical data with best practice

Red blood cell (RBC) transfusion guidelines correctly promote a general restrictive transfusion approach for anemic hospitalized patients. Such recommendations have been derived from evaluation of specific patient populations, and it is important to recognize that engaging a strict guideline approach has the potential to incur harm if the clinician fails to provide a comprehensive review of the patient’s physiological status in determining the benefit and risks of transfusion. We reviewed the data in support of a restrictive or a more liberal RBC transfusion practice, and examined the quality of the datasets and manner of their interpretation to provide better context by which a physician can make a sound decision regarding RBC transfusion therapy. Reviewed studies included PubMed-cited (1974 to 2013) prospective randomized clinical trials, prospective subset analyses of randomized studies, nonrandomized controlled trials, observational case series, consecutive and nonconsecutive case series, and review articles. Prospective randomized clinical trials were acknowledged and emphasized as the best-quality evidence. The results of the analysis support that restrictive RBC transfusion practices appear safe in the hospitalized populations studied, although patients with acute coronary syndromes, traumatic brain injury and patients at risk for brain or spinal cord ischemia were not well represented in the reviewed studies. The lack of quality data regarding the purported adverse effects of RBC transfusion at best suggests that restrictive strategies are no worse than liberal strategies under the studied protocol conditions, and RBC transfusion therapy in the majority of instances represents a marker for greater severity of illness. The conclusion is that in the majority of clinical settings a restrictive RBC transfusion strategy is cost-effective, reduces the risk of adverse events specific to transfusion, and introduces no harm. In anemic patients with ongoing hemorrhage, with risk of significant bleeding, or with concurrent ischemic brain, spinal cord, or myocardium, the optimal hemoglobin transfusion trigger remains unknown. Broad-based adherence to guideline approaches of therapy must respect the individual patient condition as interpreted by comprehensive clinical review.

Protein kinase C inhibitor sotrastaurin in de novo liver transplant recipients: a randomized phase II trial

Efficacy and safety of protein kinase C inhibitor sotrastaurin (STN) with tacrolimus (TAC) was assessed in a 24-month, multicenter, phase II study in de novo liver transplant recipients. A total of 204 patients were randomized (1:1:1:1) to STN 200 mg b.i.d. + standard-exposure TAC (n = 50) or reduced-exposure TAC (n = 52), STN 300 mg b.i.d. + reduced-exposure TAC (n = 50), or mycophenolate mofetil (MMF) 1 g b.i.d. + standard-exposure TAC (control, n = 52); all with steroids. Owing to premature study termination, treatment comparisons were only conducted for Month 6. At Month 6, composite efficacy failure rates (treated biopsy-proven acute rejection episodes of Banff grade ≥1, graft loss, or death) were 25.0%, 16.5%, 20.9% and 15.9% for STN 200 mg + standard TAC, STN 200 mg + reduced TAC, STN 300 mg + reduced TAC and control groups, respectively. Median estimated glomerular filtration rates were 84.0, 83.3, 81.1 and 75.3 mL/min/1.73 m(2), respectively. Gastrointestinal events (constipation, diarrhea, and nausea), infection, and tachycardia were more frequent in STN groups. More patients in STN groups experienced serious adverse events compared with the control group (62.3-70.8% vs. 51.9%). STN-based regimens were associated with a higher efficacy failure rate and higher incidence of adverse events with no significant difference in renal function between the groups.

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.

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.

Remain recipient partial liver during liver transplant after Hassab

BACKGROUND

The Hassab procedure is the primary method for treating and preventing recurrent esophagogastric variceal bleeding in portal hypertension patients. These patients have worsening liver function and eventually require liver transplantation. Abnormal anatomical structures and severe tissue adhesion caused by the Hassab procedure increase the risks of transplantation. We investigated the safety and efficacy of retaining part of the left lateral hepatic lobe during transplantation.

MATERIALS AND METHODS

This retrospective study evaluated outcomes in 22 patients who underwent the Hassab procedure followed by liver transplantation. The patients were separated into two groups: group A (complete liver resection, n = 14) and group B (incomplete liver resection with left lateral remnant, n = 8). We statistically analyzed pre-, intra-, and post-operative variables in both groups.

RESULTS

Preoperative demographic data showed no significant differences between the groups. Operation time was significantly greater in group A (10.85 ± 0.79 h) than in group B (7.25 ± 0.59 h), and median blood loss (2807 ± 472 mL) was significantly greater in group A than in group B (1023 ± 141 mL, P < 0.05 for both). Overall complication rates were not significantly different; the 1- and 3-y survival rates were 85.7% and 71.4% for group A and 87.5% and 75.0% for group B, respectively (P > 0.05).

CONCLUSIONS

Retention of some left hepatic lobe tissue during liver transplantation after the Hassab procedure is safe and feasible because it increases the success rate by reducing surgical difficulty and time.

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.

Prediction of newly developed acute renal failure using serum phosphorus concentrations after living-donor liver transplantation

OBJECTIVE

This retrospective study investigated the predictive role of serum phosphorus concentration for acute renal failure (ARF), defined by the Risk Injury Failure Loss End-stage kidney disease (RIFLE) criteria, after living-donor liver transplantation (LDLT).

METHODS

Perioperative factors, including serum phosphorus concentrations, in LDLT recipients without pre-existing renal dysfunction were retrospectively analysed and compared between patients with or without post-LDLT ARF.

RESULTS

A total of 45 patients out of 350 (12.9%) met the RIFLE ARF criteria and experienced significantly higher postoperative mortality, longer intensive care unit stay and more frequent graft dysfunction than those patients without post-LDLT ARF. Multivariate logistic regression analyses showed that a serum phosphorus concentration ≥ 4.5 mg/dl on postoperative day 1 (relative risk [RR] 5.31; 95% confidence interval [CI] 2.56, 11.03), a preoperative model for end-stage liver disease score 20 points (RR 4.17, 95% CI 2.04, 8.52), and packed red blood cell transfusion 10 units (RR 2.55, 95% CI 1.13, 5.88) were independent risk factors for post-LDLT ARF.

CONCLUSIONS

Hyperphosphataemia on postoperative day 1 could be an early and simple indicator of ARF occurrence after LDLT.

Acute kidney injury after orthotopic liver transplantation

Acute kidney injury (AKI), one of the most frequent complications in the early period after liver transplantation, causes serious obstacles in the management of these patients affecting their outcomes. We studied retrospectively 79 subjects who underwent orthotopic liver transplantation (OLT). AKI was defined as an elevation of serum creatinine 1.5 times above baseline or an absolute serum creatinine level > 2 mg/dL. Our aim was to analyze the incidence, correlation with prior renal impairment, outcomes of AKI after OLT. Twenty-two patients (29.3%) developed AKI after OLT with 31.81% of the requiring renal replacement therapy. Among patients with AKI the duration of mechanical ventilation was prolonged (P = .001), length of stay in the intensive care unit was greater (P = .001), infections were more common (P = .016), and 30-day and 1-year mortality rates higher (P = .018). Logistic regression analysis showed post-OLT AKI to be an independent risk factor for 1-year mortality after OLT.

The relationship between preoperative creatinine clearance and outcomes for patients undergoing liver transplantation: a retrospective observational study

Background

Renal failure with following continuous renal replacement therapy is a major clinical problem in liver transplant recipients, with reported incidences of 3% to 20%. Little is known about the significance of postoperative acute renal failure or acute-on-chronic renal failure to postoperative outcome in liver transplant recipients.

Methods

In this post hoc analysis we compared the mortality rates of 135 consecutive liver transplant recipients over 6 years in our center subject to their renal baseline conditions and postoperative RRT. We classified the patients into 4 groups, according to their preoperative calculated Cockcroft formula and the incidence of postoperative renal replacement therapy. Data then were analyzed in regard to mortality rates and in addition to pre- and peritransplant risk factors.

Results

There was a significant difference in ICU mortality (p=.008), hospital mortality (p=.002) and cumulative survival (p<.0001) between the groups. The highest mortality rate occurred in the group with RRT and normal baseline kidney function (20% ICU mortality, 26.6% hospital mortality and 50% cumulative 1-year mortality, respectively). The hazard ratio in this group was 9.6 (CI 3.2-28.6, p=.0001).

Conclusion

This study shows that in liver transplant recipient’s acute renal failure with postoperative RRT is associated with mortality and the mortality rate is higher than in patients with acute-on-chronic renal failure and postoperative renal replacement therapy.

Safety of living donor liver transplantation using older donors

BACKGROUND

There is limited information concerning older donors in living donor liver transplantation (LDLT). In the present study, we attempted to clarify whether it is safe to use older donors in LDLT.

METHODS

A total of 129 cases were reviewed in the present study. Donors and recipients were divided into group A (donors aged ≥ 50 y, n=21) and group B (donors aged <50 y, n=108). The pre-, intra-, and postoperative variables of the two groups were statistically compared.

RESULTS

Donors' complication rates were 38.10% and 28.70% for groups A and B, respectively (P=0.719). The overall 1-, 3-, and 5-y survival rates were 90%, 80%, and 66% for group A and 86%, 83%, and 75% for group B, respectively (P=0.573). Similar Clavien III or more complication rates for recipients were observed.

CONCLUSIONS

The present study suggested that LDLT using older donors had no negative influence on the outcomes of both donors and recipients.

A learning curve for living donor liver transplantation

BACKGROUND

The number of living donor liver transplantations performed has increased rapidly in many Eastern transplant centres. However, the impact of the transplant centres' experience and learning on the transplant outcomes are not well established. Aim of the study was to evaluate the learning curve for living donor liver transplantation in our centre.

METHODS

Data from 156 recipients and 156 donors who underwent surgery were reviewed. Intraoperative data and postoperative outcomes of both donors and recipients were retrospectively analysed. Recipients and donors were divided into three groups that consisted of 52 consecutive cases each.

RESULTS

Surgical duration and intraoperative blood loss during donor surgery were decreased significantly between the earlier and the more recent cases (423±39 vs. 400±44 min and 959±523 vs. 731±278 mL, respectively; P<0.01). Rates of postoperative complications and functional changes were not statistically different amongst the three donor groups. Immediate complication rate of the first 52 recipients was higher than those of the second and third cohorts. Long-term survival rates of the three recipient groups were similar.

CONCLUSIONS

The learning curve greatly influenced immediate outcomes of recipients during the early transplant period. However, it had little influence on donor outcome; long-term outcome improvement of recipients did not depend on the accumulation of experience alone.

[Retrospective comparative study between sevoflurane and propofol in maintaining anaesthesia during liver transplant: Effects on kidney and liver function]

OBJECTIVE

To compare the post-operative effects of sevoflurane versus propofol on liver and kidney function while maintaining anaesthesia in the orthotopic liver transplant (OLT), as well as to analyse the short-term survival as regards these functions.

PATIENTS AND METHODS

A retrospective analysis was conducted on patients subjected to an OLT between January 2002 and December 2009. Patients on pre-transplant haemodialysis, re-transplants, and hepatorenal transplants were excluded. The incidence of acute renal failure, initial dysfunction of the graft, reperfusion syndrome, rejection, and the transaminase peak depending value depending on the hypnotic used, were recorded.

RESULTS

About one-third (31.2%) of the patients developed acute renal failure and 11.9% an initial dysfunction, with no differences between the groups. There was a tendency for a lower incidence of initial dysfunction of the graft in the sevoflurane group (8.6% compared to 12.8%), a lower transaminase peak (greater than 2000 U/L, 12.1% versus 15.9%), and a lower incidence of reperfusion syndrome (10.3% compared to 21.6%).

CONCLUSIONS

Despite the fact that the renal metabolism sevoflurane is elevated, we did not find any higher incidence of acute renal failure. Sevoflurane in the liver transplant anaesthesia is as least equally as safe propofol as regards renal function and liver function. New prospective studies are needed to clarify the possible effects of the hypnotic in liver transplant.

Analysis of infections in the first 3-month after living donor liver transplantation

AIM: To identify factors related to serious postoperative bacterial and fungal infections in the first 3 mo after living donor liver transplantation (LDLT).

METHODS: In the present study, the data of 207 patients from 2004 to 2011 were reviewed. The pre-, intra- and post-operative factors were statistically analyzed. All transplantations were approved by the ethics committee of West China Hospital, Sichuan University. Patients with definitely preoperative infections and infections within 48 h after transplantation were excluded from current study. All potential risk factors were analyzed using univariate analyses. Factors significant at a P < 0.10 in the univariate analyses were involved in the multivariate analyses. The diagnostic accuracy of the identified risk factors was evaluated using receiver operating curve.

RESULTS: The serious bacterial and fungal infection rates were 14.01% and 4.35% respectively. Enterococcus faecium was the predominant bacterial pathogen, whereas Candida albicans was the most common fungal pathogen. Lung was the most common infection site for both bacterial and fungal infections. Recipient age older than 45 years, preoperative hyponatremia, intensive care unit stay longer than 9 d, postoperative bile leak and severe hyperglycemia were independent risk factors for postoperative bacterial infection. Massive red blood cells transfusion and postoperative bacterial infection may be related to postoperative fungal infection.

CONCLUSION: Predictive risk factors for bacterial and fungal infections were indentified in current study. Pre-, intra- and post-operative factors can cause postoperative bacterial and fungal infections after LDLT.

Risk factors and outcomes of massive red blood cell transfusion following living donor liver transplantation

OBJECTIVES

To identify the factors influencing blood loss and secondary blood transfusion and to investigate the outcomes of patients who underwent a massive blood transfusion (MBT) following living donor liver transplantation (LDLT).

METHODS

Patients who underwent primary adult-to-adult right hepatic lobe LDLT were included in the study, and were divided into the MBT group [≥6 red blood cell (RBC) units in 24 h] and the non-massive blood transfusion (NMBT) group (<6 RBC units in 24 h). All potential risk factors, length of intensive care unit (ICU) stay and long-term survival rate of the patients in the two groups were analyzed.

RESULTS

The data of 181 eligible patients were retrospectively analyzed. A decreased long-term survival rate, a higher incidence of postoperative infection and prolonged ICU stay were observed in the MBT group. No significant difference was observed in survival rate between patients having platelet transfusion>2 units and ≤2 units. Hemoglobin<100 g/L, platelet counts<70×10(9)/L, fibrinogen level<1.5 g/L and history of upper abdominal surgery were found to be independent risk factors.

CONCLUSIONS

Blood transfusion during LDLT can be predicted using preoperative variables. Massive RBC transfusion may lead to poor long-term survival, higher postoperative infection rate and prolonged ICU stay. Platelet transfusion may not be a risk factor for long-term survival.

Outcomes of patients with benign liver diseases undergoing living donor versus deceased donor liver transplantation

BACKGROUND/AIMS

The number of people undergoing living donor liver transplantation (LDLT) has increased rapidly in many transplant centres. Patients considering LDLT need to know whether LDLT is riskier than deceased donor liver transplantation (DDLT). The aim of this study was to compare the outcomes of patients undergoing LDLT versus DDLT.

METHODS

A total of 349 patients with benign liver diseases were recruited from 2005 to 2011 for this study. LDLT was performed in 128 patients, and DDLT was performed in 221 patients. Pre- and intra-operative variables for the two groups were compared. Statistically analysed post-operative outcomes include the postoperative incidence of complication, biliary and vascular complication, hepatitis B virus (HBV) recurrence, long-term survival rate and outcomes of emergency transplantation.

RESULTS

The waiting times were 22.10±15.31 days for the patients undergoing LDLT versus 35.81±29.18 days for the patients undergoing DDLT. The cold ischemia time (CIT) was 119.34±19.75 minutes for the LDLT group and 346±154.18 for DDLT group. LDLT group had higher intraoperative blood loss, but red blood cell (RBC) transfusion was not different. Similar ≥ Clavien III complications, vascular complications, hepatitis B virus (HBV) recurrence and long-term survival rates were noted. LDLT patients suffered a higher incidence of biliary complications in the early postoperative days. However, during the long-term follow-up period, biliary complication rates were similar between the two groups. The long-term survival rate of patients undergoing emergency transplantation was lower than of patients undergoing elective transplantation. However, no significant difference was observed between emergency LDLT and emergency DDLT.

CONCLUSIONS

Patients undergoing LDLT achieved similar outcomes to patients undergoing DDLT. Although LDLT patients may suffer a higher incidence of early biliary complications, the total biliary complication rate was similar during the long-term follow-up period.

Management of renal dysfunction in patients receiving a liver transplant

Renal dysfunction is a frequent complication in patients with endstage liver disease awaiting orthotopic liver transplantation. Although the stereotypical form of renal dysfunction is the hepatorenal syndrome, common causes of acute kidney injury include prerenal azotemia and acute tubular necrosis in this population. Management involves hemodynamic support, renal replacement therapy, and mitigation of risk factors. Renal dysfunction in a cirrhotic patient usually implies a poor prognosis in the absence of liver transplantation. An important issue is the frequent need for kidney, in addition to liver, transplantation if renal insufficiency has been persistent in a decompensated cirrhotic.

Calcineurin-inhibitor minimization in liver transplant patients with calcineurin-inhibitor-related renal dysfunction: a meta-analysis

Background

Introduction of calcineurin-inhibitor (CNI) has made transplantation a miracle in the past century. However, the side effects of long-term use of CNI turn out to be one of the major challenges in the current century. Among these, renal dysfunction attracts more and more attention. Herein, we undertook a meta-analysis to evaluate the efficacy and safety of calcineurin-inhibitor (CNI) minimization protocols in liver transplant recipients with CNI-related renal dysfunction.

Methods

We included randomized trials with no year and language restriction. All data were analyzed using random effect model by Review Manager 5.0. The primary endpoints were glomerular filtration rate (GFR), serum creatinine level (sCr) and creatinine clearance rate (CrCl), and the secondary endpoints were acute rejection episodes, incidence of infection and patient survival at the end of follow-up.

Results

GFR was significantly improved in CNI minimization group than in routine CNI regimen group (Z = 5.45, P<0.00001; I² = 0%). Likely, sCr level was significantly lower in the CNI minimization group (Z = 2.84, P = 0.005; I² = 39%). However, CrCl was not significantly higher in the CNI minimization group (Z = 1.59, P = 0.11; I² = 0%). Both acute rejection episodes and patient survival were comparable between two groups (rejection: Z = 0.01, P = 0.99; I² = 0%; survival: Z = 0.28, P = 0.78; I² = 0%, respectively). However, current CNI minimization protocols may be related to a higher incidence of infections (Z = 3.06, P = 0.002; I² = 0%).

Conclusion

CNI minimization can preserve or even improve renal function in liver transplant patients with renal impairment, while sharing similar short term acute rejection rate and patient survival with routine CNI regimen.

Safety and feasibility of third-party multipotent adult progenitor cells for immunomodulation therapy after liver transplantation--a phase I study (MISOT-I)

BACKGROUND

Liver transplantation is the definitive treatment for many end-stage liver diseases. However, the life-long immunosuppression needed to prevent graft rejection causes clinically significant side effects. Cellular immunomodulatory therapies may allow the dose of immunosuppressive drugs to be reduced. In the current protocol, we propose to complement immunosuppressive pharmacotherapy with third-party multipotent adult progenitor cells (MAPCs), a culture-selected population of adult adherent stem cells derived from bone marrow that has been shown to display potent immunomodulatory and regenerative properties. In animal models, MAPCs reduce the need for pharmacological immunosuppression after experimental solid organ transplantation and regenerate damaged organs.

METHODS

Patients enrolled in this phase I, single-arm, single-center safety and feasibility study (n = 3-24) will receive 2 doses of third-party MAPCs after liver transplantation, on days 1 and 3, in addition to a calcineurin-inhibitor-free "bottom-up" immunosuppressive regimen with basiliximab, mycophenolic acid, and steroids. The study objective is to evaluate the safety and clinical feasibility of MAPC administration in this patient cohort. The primary endpoint of the study is safety, assessed by standardized dose-limiting toxicity events. One secondary endpoint is the time until first biopsy-proven acute rejection, in order to collect first evidence of efficacy. Dose escalation (150, 300, 450, and 600 million MAPCs) will be done according to a 3 + 3 classical escalation design (4 groups of 3-6 patients each).

DISCUSSION

If MAPCs are safe for patients undergoing liver transplantation in this study, a phase II/III trial will be conducted to assess their clinical efficacy.

Predictors of patient survival following living donor liver transplantation

BACKGROUND

Living donor liver transplantation (LDLT) is considered to be the alterative choice in light of the great shortage of cadaveric donors. However, the characteristics of the patients who will benefit from LDLT have not been well identified. The aim of this study was to define the pre- and intra-operative factors that may influence patient outcome.

METHODS

The data from 102 LDLT patients who had operations between 2002 and 2009 were collected and analyzed retrospectively. Data were analyzed using uni- and multi-variate analysis according to factors that are known to be associated with outcome in these patients.

RESULTS

Overall, the accurate survival rate of recipients at 1, 3, and 5 years was 84%, 76%, and 70%, respectively. The independent risk factors, preoperative renal dysfunction, intraoperative red blood cell transfusions of greater than 5 units, and female to male match (donor to recipient matching), were identified by Cox regression analysis. The pre-transplant model for end-stage liver disease score and a graft to recipient weight ratio of less than 0.8% were not predictive of outcome. The overall 1-, 3-, and 5-year survival of patients with one or no risk factors and two or more risk factors were 91%, 86%, and 83% and 67%, 56%, and 47%, respectively (P<0.0001).

CONCLUSIONS

In our retrospective study, preoperative renal dysfunction, intraoperative red blood cell transfusions of greater than 5 units, and female to male gender match were independent risk factors for LDLT recipient outcome. Two or more of these risk factors may contribute to poor outcome.

Pre-transplant kidney function predicts chronic kidney disease after liver transplant: meta-analysis of observational studies

BACKGROUND

Chronic kidney disease is a common problem in long-term survivors after liver transplantation. Several studies to clarify the risk factors for incidence of chronic kidney disease among liver transplant recipients, including preoperative kidney function, have yielded conflicting results.

AIM

The aim of this study was to conduct a systematic review of the published medical literature on the impact of pre-transplant kidney function on the occurrence of chronic kidney disease after liver transplantation.

METHODS

Study-specific relative risks were weighted by the inverse of their variance to obtain fixed- and random-effects pooled estimates for incidence of chronic kidney disease across the published studies. The relative risk of chronic kidney disease after liver transplantation according to pre-transplant glomerular filtration rate was regarded as the most reliable outcome end-point.

RESULTS

We identified seven studies (38,036 unique liver transplant recipients). A stratified analysis including only studies provided with glomerular filtration rate at transplant reported that the summary estimate of relative risk and 95% confidence intervals (CIs) for developing chronic renal failure among liver transplant recipients with diminished renal function at transplant was 2.12 (95% CI, 1.01; 4.46) (random-effects model). The p value for study heterogeneity was significant (p = 0.0001). Post-transplant chronic kidney disease shows impact on survival; the summary estimate for the adjusted relative risk of all-cause mortality with chronic kidney disease after liver transplant was 4.35 (95% confidence Intervals, 3.34; 5.66), p = 0.0001 (random-effects model).

CONCLUSIONS

An increased risk of chronic kidney disease frequently exists among liver transplant recipients with reduced renal function at transplant. The occurrence of chronic kidney disease after liver transplantation has a major impact on mortality. Additional studies are needed to understand better the natural history of chronic kidney disease among liver transplant recipients.

Critical care issues in patients after liver transplantation

The majority of patients who undergo liver transplantation (LT) spend some time in the intensive care unit during the postoperative period. For some, this is an expected part of the immediate posttransplant recovery period, whereas for others, the stay is more prolonged because of preexisting conditions, intraoperative events, or postoperative complications. In this review, 4 topics that are particularly relevant to the postoperative intensive care of LT recipients are discussed, with an emphasis on current knowledge specific to this patient group. Infectious complications are the most common causes of early posttransplant morbidity and mortality. The common patterns of infection seen in patients after LT and their management are discussed. Acute kidney injury and renal failure are common in post-LT patients. Kidney injury identification, etiologies, and risk factors and approaches to management are reviewed. The majority of patients will require weaning from mechanical ventilation in the immediate postoperative period; the approach to this is discussed along with the approach for those patients who require a prolonged period of mechanical ventilation. A poorly functioning graft requires prompt identification and appropriate management if the outcomes are to be optimized. The causes of poor graft function are systematically reviewed, and the management of these grafts is discussed.

Postliver transplant acute renal injury and failure by the RIFLE criteria in patients with normal pretransplant serum creatinine concentrations: a matched study

BACKGROUND

Acute renal injury (ARI) and acute renal failure (ARF) are serious complications after liver transplantation (LT). Few studies apply the risk, injury, function, loss, and end-stage criteria on the patients who have normal preoperative renal function. The aims of this study were to identify the incidence, risk factors, and impact of ARI and ARF in this patient population.

METHODS

After institutional review board approval, adult LT patients who had preoperative serum creatinine less than or equal to 1.5mmol/L were reviewed. Postoperative ARI and ARF were determined by the risk, injury, function, loss, and end-stage criteria. Risk factors were determined by multivariable regression. Postoperative outcomes were compared among patients with or without ARI or ARF.

RESULTS

Among 334 patients included the study, 20.4% and 18.0% had ARI or ARF in the first week after LT, respectively. Then 118 ARI or ARF patients were matched with patients without post-LT renal injury by gender, creatinine, and body mass index. Multivariable analysis showed that increased requirement of red blood cell transfusion (odds ratio [OR] 2.7-8.8, P<0.05), vasopressors (OR 2.2, P=0.018), and pre-LT albumin less than or equal to 3.5 mg/dL (OR: 2.8, P=0.003) as risk factors for post-LT ARI or ARF. Both ARI and ARF were associated with longer hospital stay and higher reoperation rate. ARF, but not ARI, was associated with higher 30-day graft failure and mortality rates.

CONCLUSION

Post-LT ARI or ARF occurred frequently in patients with normal preoperative renal function and was associated with both preoperative and intraoperative risk factors. Although both post-LT ARI and ARF are associated with significant post-LT morbidity, the impact of ARF is greater.

Risk factors for acute kidney injury following orthotopic liver transplantation: the impact of changes in renal function while patients await transplantation

Background

Acute kidney injury (AKI) occurs commonly in the setting of orthotopic liver transplantation (OLT). To date, the correlation between AKI post-OLT and pre-operative changes in renal function has not been rigorously examined.

Methods

To determine the impact of pre-OLT changes in renal function on AKI post-OLT, as well as to identify risk factors for AKI, we analyzed the prospectively maintained NIDDK Liver Transplantation Database, which includes patients who received their first OLT between April 15, 1990, and June 30, 1994. We used the AKI Network definition of AKI.

Results

Surprisingly, univariate analysis revealed that worsening renal function while awaiting OLT was protective to the development of AKI post-OLT. Independent predictors of AKI were increased body mass index, increased Childs-Pugh-Turcott score, decreased urine output during cross-clamp, improved renal function while awaiting OLT, increased post-operative stroke volume, non-Caucasian race, and post-operative use of tacrolimus.

Conclusions

The correlation between improving renal function pre-OLT and AKI post-OLT may represent true protection (via ischemic pre-conditioning) or, alternatively, a masking of milder forms of AKI (via improved renal perfusion through correction of the cirrhotic milieu). These results highlight the complex interaction between liver and kidney disease, and suggest that not only the etiology but also the course of pre-OLT renal dysfunction may be a critical determinant of renal function post-OLT.

Effects of low central venous pressure during preanhepatic phase on blood loss and liver and renal function in liver transplantation

BACKGROUND

Although the low central venous pressure (LCVP) technique is used to decrease blood loss during liver resection, its efficacy and safety during transplant procedures are still debatable. Our study aimed to assess the effects of this technique and its clinical safety for recipients undergoing liver transplantation.

METHODS

Eighty-six adult patients were randomly divided into a LCVP group and a control group. In the LCVP group, CVP was maintained below 5 mmHg or 40% lower than baseline during the preanhepatic phase by limiting infusion volume, manipulating the patient's posture, and administration of somatostatin and nitroglycerine. Recipients in the control group received standard care. Hemodynamics, blood loss, liver function, and renal function of the two groups were compared perioperatively.

RESULTS

A lower CVP was maintained in the LCVP group during the preanhepatic phase, resulting in a significant decrease in blood loss (1922 +/- 1429 vs. 3111 +/- 1833 ml, P < 0.05) and transfusion volume (1200 +/- 800 vs. 2400 +/- 1200 ml, P < 0.05) intraoperatively. Compared with the control group, the LCVP group had a significantly lower mean arterial pressure at 2 h after the start of the operation (74 +/- 11 vs. 84 +/- 14 mmHg, P < 0.05), a lower lactate value at the end of the operation (5.9 +/- 3.0 vs. 7.2 +/- 3.0 mmol/l, P < 0.05), and a better preservation of liver function after the declamping of the portal vein. There were no significant differences in perioperative renal function and postoperative complications between the groups.

CONCLUSIONS

The LCVP technique during the preanhepatic phase reduced intraoperative blood loss, protected liver function, and had no detrimental effects on renal function in LT.

Study protocol: a pilot study to determine the safety and efficacy of induction-therapy, de novo MPA and delayed mTOR-inhibition in liver transplant recipients with impaired renal function. PATRON-study

BACKGROUND

Patients undergoing liver transplantation with preexisting renal dysfunction are prone to further renal impairment with the early postoperative use of Calcineurin-inhibitors. However, there is only little scientific evidence for the safety and efficacy of de novo CNI free "bottom-up" regimens in patients with impaired renal function undergoing liver transplantation. This is a single-center study pilot-study (PATRON07) investigating safety and efficacy of CNI-free, "bottom-up" immunosuppressive (IS) strategy in patients undergoing liver transplantation (LT) with renal impairment prior to LT.

METHODS/DESIGN

Patients older than 18 years with renal impairment at the time of liver transplantation eGFR < 50 ml/min and/or serum creatinine levels > 1.5 mg/dL will be included. Patients in will receive a CNI-free combination therapy (basiliximab, MMF, steroids and delayed Sirolimus). Primary endpoint is the incidence of steroid resistant acute rejection within the first 30 days after LT. The study is designed as prospective two-step trial requiring a maximum of 29 patients. In the first step, 9 patients will be included. If 8 or more patients show no signs of biopsy proven steroid resistant rejection, additional 20 patients will be included. If in the second step a total of 27 or more patients reach the primary endpoint the regimen is regarded to be safe and efficient.

DISCUSSION

If a CNI-free-"bottom-up" IS strategy is safe and effective, this may be an innovative concept in contrast to classic top-down strategies that could improve the patient short and long-time renal function as well as overall complications and survival after LT. The results of PATRON07 may be the basis for a large multicenter RCT investigating the new "bottom-up" immunosuppressive strategy in patients with poor renal function prior to LT.http://www.clinicaltrials.gov-identifier: NCT00604357.

Model of end stage liver disease (MELD) score greater than 23 predicts length of stay in the ICU but not mortality in liver transplant recipients

Introduction

The impact of model of end stage liver disease (MELD) score on postoperative morbidity and mortality is still elusive, especially for high MELD. There are reports of poorer patient outcome in transplant candidates with high MELD score, others though report no influence of MELD score on outcome and survival.

Methods

We retrospectively analyzed data of 144 consecutive liver transplant recipients over a 72-month period in our transplant unit, from January 2003 until December 2008 and performed uni- and multivariate analysis for morbidity and mortality, in particular to define the influence of MELD to these parameters.

Results

This study identified MELD score greater than 23 as an independent risk factor of morbidity represented by intensive care unit (ICU) stay longer than 10 days (odds ratio 7.0) but in contrast had no negative impact on mortality. Furthermore, we identified transfusion of more than 7 units of red blood cells as independent risk factor for mortality (hazard ratio 7.6) and for prolonged ICU stay (odds ratio [OR] 7.8) together with transfusion of more than 10 units of fresh frozen plasma (OR 11.6). Postoperative renal failure is a strong predictor of morbidity (OR 7.9) and postoperative renal replacement therapy was highly associated with increased mortality (hazard ratio 6.8), as was hepato renal syndrome prior to transplantation (hazard ratio 13.2).

Conclusions

This study identified MELD score greater than 23 as an independent risk factor of morbidity represented by ICU stay longer than 10 days but in contrast had no negative impact on mortality. This finding supports the transplantation of patients with high MELD score but only with knowledge of increased morbidity.

Conversion from a calcineurin inhibitor to everolimus therapy in maintenance liver transplant recipients: a prospective, randomized, multicenter trial

Calcineurin inhibitors (CNIs) contribute to renal dysfunction following liver transplantation. This prospective, randomized, multicenter, 6-month study (with an additional 6 months of follow-up) evaluated whether everolimus with CNI reduction or discontinuation would improve renal function in maintenance liver transplant recipients experiencing CNI-related renal impairment. Patients started everolimus therapy with CNI reduction or discontinuation (n = 72) or continued receiving standard-exposure CNI (n = 73). At month 6, 80% of the patients who had converted to everolimus had discontinued the CNI. The mean change in creatinine clearance (CrCl) from baseline to month 6 was similar between groups (everolimus, 1.0 +/- 10.2 mL/minute; controls, 2.3 +/- 7.8 mL/minute; P = 0.46), so the primary study endpoint (8 mL/minute difference in the change in CrCl) was not achieved. Among patients who continued everolimus according to the protocol, the mean increase in CrCl was 2.1 (n = 53) and 3.8 mL/minute (n = 38) at months 6 and 12, respectively, versus 2.4 (n = 68) and 3.5 mL/minute in controls (n = 51). The high frequency of CNI dose reductions in controls (77% of the patients) and the relatively long mean time post-transplant (>3 years) likely contributed to the small difference in CrCl. Biopsy-proven acute rejection occurred in 1.4% of the patients in each group, with no graft losses. Study drug discontinuation was higher in everolimus-treated patients, and adverse events were more frequent. These data demonstrate that everolimus allows for discontinuation or a major reduction of CNI exposure in liver allograft recipients suffering CNI-related renal dysfunction without a loss of efficacy. Trials targeting earlier conversion post-transplantation are required to confirm the efficacy and safety of everolimus for improving renal function after liver transplantation.

Management of renal dysfunction in the liver transplant recipient

PURPOSE OF REVIEW

Acute and chronic kidney injury following orthotopic liver transplantation (OLT) is associated with increased morbidity and mortality. With the increasing longevity of liver transplant recipients, chronic kidney disease (CKD) has become an increasingly prevalent complication among long-term survivors. This article provides an overview of the literature on suggested risk factors for acute and CKD following OLT and a discussion of an approach to their medical management.

RECENT FINDINGS

In OLT candidates with pretransplant renal dysfunction, the use of interleukin-2 receptor blockers or antithymocyte globulin induction therapy in conjunction with delayed introduction of calcineurin inhibitors may preserve early renal function. In long-term stable OLT recipients with established calcineurin inhibitor nephrotoxicity, calcineurin inhibitor minimization or withdrawal protocols may halt or ameliorate renal dysfunction without compromising patient and graft survival. However, large-scale, multicenter, randomized controlled trials are still needed.

SUMMARY

The occurrence of acute kidney injury is common immediately after OLT, whereas the incidence of CKD and end-stage renal disease increases with time. Identifying patients at risk for acute kidney injury and CKD following OLT and early implementation of measures to preserve, halt, or ameliorate the progression of renal dysfunction should be an integral part in the management of OLT recipients.

[Liver transplantation: influence of donor-related factors]

OBJECTIVE

To detect donor characteristics related to graft function after orthotopic liver transplantation (OLT).

DESIGN

Retrospective cohort study.

CONTEXT

Polyvalent intensive care unit.

PATIENTS

145 liver transplant recipients and their respective donors.

INTERVENTIONS

None.

MAIN VARIABLES OF INTEREST

In donors: age, hypernatremia, and infection. In recipients: reperfusion syndrome, coagulopathy, infection, ARDS, shock, kidney failure, primary graft dysfunction, and mortality.

RESULTS

71.7% of recipients were male. Mean recipient age was 54.5 +/- 9.9 years; 66.2% of patients were classified as Child B and and 19.3% as Child C. The mean model for end-stage liver disease (MELD) score was 14.6 +/- 4.8 and the mean APACHE II score was 17.3 +/- 4.9. A total of 64.1% of the donors were male. Mean donor age was 42.3 +/- 16.3 years, and mean APACHE II score was 22.3 +/- 5.8. Donor age > 65 years was associated to higher recipient aspartate aminotransferase (AST) levels but not to increased complications or mortality. No other donor factors (including age, sex, serum sodium, severity level, transfusions, hemodynamic alterations, renal dysfunction, or infection) were associated to evolution or prognosis. Infection was diagnosed in 18 recipients (12.4%) in the postoperative period; the incidence of infection in recipients that received an organ from infected donors was not different from those that received an organ from an uninfected donor (14.6% versus 11.5%; p > 0.05).

CONCLUSIONS

We detected no donor characteristics related to graft function or the appearance of complications in recipients during the immediate postoperative period. Donor age > 65 years and documented but appropriately treated bacteremia posed no risk for the viability of the liver after transplantation.

Efficacy of red blood cell transfusion in the critically ill: a systematic review of the literature

BACKGROUND

Red blood cell (RBC) transfusions are common in intensive care unit, trauma, and surgical patients. However, the hematocrit that should be maintained in any particular patient because the risks of further transfusion of RBC outweigh the benefits remains unclear.

OBJECTIVE

A systematic review of the literature to determine the association between red blood cell transfusion, and morbidity and mortality in high-risk hospitalized patients.

DATA SOURCES

MEDLINE, Embase, Cochrane Register of Controlled Trials, and citation review of relevant primary and review articles.

STUDY SELECTION

Cohort studies that assessed the independent effect of RBC transfusion on patient outcomes. From 571 articles screened, 45 met inclusion criteria and were included for data extraction.

DATA EXTRACTION

Forty-five studies including 272,596 were identified (the outcomes from one study were reported in four separate publications). The outcome measures were mortality, infections, multiorgan dysfunction syndrome, and acute respiratory distress syndrome. The overall risks vs. benefits of RBC transfusion on patient outcome in each study was classified as (i) risks outweigh benefits, (ii) neutral risk, and (iii) benefits outweigh risks. The odds ratio and 95% confidence interval for each outcome measure was recorded if available. The pooled odds ratios were determined using meta-analytic techniques.

DATA SYNTHESIS

Forty-five observational studies with a median of 687 patients/study (range, 63-78,974) were analyzed. In 42 of the 45 studies the risks of RBC transfusion outweighed the benefits; the risk was neutral in two studies with the benefits outweighing the risks in a subgroup of a single study (elderly patients with an acute myocardial infarction and a hematocrit <30%). Seventeen of 18 studies, demonstrated that RBC transfusions were an independent predictor of death; the pooled odds ratio (12 studies) was 1.7 (95% confidence interval, 1.4-1.9). Twenty-two studies examined the association between RBC transfusion and nosocomial infection; in all these studies blood transfusion was an independent risk factor for infection. The pooled odds ratio (nine studies) for developing an infectious complication was 1.8 (95% confidence interval, 1.5-2.2). RBC transfusions similarly increased the risk of developing multi-organ dysfunction syndrome (three studies) and acute respiratory distress syndrome (six studies). The pooled odds ratio for developing acute respiratory distress syndrome was 2.5 (95% confidence interval, 1.6-3.3).

CONCLUSIONS

Despite the inherent limitations in the analysis of cohort studies, our analysis suggests that in adult, intensive care unit, trauma, and surgical patients, RBC transfusions are associated with increased morbidity and mortality and therefore, current transfusion practices may require reevaluation. The risks and benefits of RBC transfusion should be assessed in every patient before transfusion.

A new serum cystatin C-based equation for assessing glomerular filtration rate in liver transplantation

BACKGROUND

Cystatin C (CysC) has been identified to be an alternative marker of glomerular filtration rate (GFR), but no CysC-based equation has been developed for patients receiving liver transplantation.

METHODS

Serum CysC and (99m)Tc-DTPA clearance (true GFR) were measured simultaneously on post-transplant days 1, 4 and 7. A new equation was constructed based on an observation group of 30 patients and its predictive ability was compared with three other CysC-based equations (Hoek, Filler and Larsson) based on a validation group of 30 patients.

RESULTS

The new equation for calculating GFR was defined as 19.12+96.21x(1/CysC) and the derived GFR was estimated at 97.4+/-30.2 mL/min/1.73 m(2) and was close to the true GFR (96.8+/-32.8 mL/min/1.73 m(2)). Estimates of GFR by Hoek, Filler and Larsson formulas (61.4+/-25.4, 73.8+/-31.9 and 61.3+/-29.6mL/min/1.73 m(2), respectively) differed significantly from the true GFR. Correlation between the true GFR and all formulas showed no significant difference. Bias was neglectable for the new equation (mean difference: 0.6 mL/min/1.73 m(2)) but remarkable for the other three equations (mean difference: -22.9 to -35.4 mL/min/1.73 m(2)). Accuracy within 10%, 30% and 50% of the true GFR for the new equation (30.0%, 76.7% and 93.3%) was significantly higher than those of the other three equations (p<0.001 for all).

CONCLUSIONS

A new serum CysC-based equation was established in this study and it was shown to be accurate in estimating GFR after liver transplantation, compared to the formulas of Hoek, Filler and Larsson.

Preserving renal function in liver transplant recipients with rabbit anti-thymocyte globulin and delayed initiation of calcineurin inhibitors

Early renal dysfunction following liver transplantation is associated with increased morbidity and mortality. To evaluate the impact of delayed initiation of calcineurin inhibitor on renal function, we conducted a retrospective study comparing 118 liver transplant recipients who received rabbit anti-thymocyte globulin and delayed initiation of calcineurin inhibitor with 80 liver transplant recipients who received no antibody and early initiation of calcineurin inhibitor (control group). All patients received mycophenolate mofetil and steroids. Delayed calcineurin inhibitor initiation with anti-thymocyte globulin was associated with significant improvement in renal function throughout the first year post-transplant. At 12 months post-transplant, patients treated with this regimen experienced lower serum creatinine (1.4 +/- 0.5 versus 1.7 +/- 0.5 mg/dL, P < 0.001), a higher estimated glomerular filtration rate (57.4 +/- 20.5 versus 43.7 +/- 14.4 mL/min/1.73 m(2), P < 0.001), and less dependence on dialysis (0.8% versus 13%, P < 0.001) in comparison with no antibody and early calcineurin inhibitor initiation. Patient survival and graft survival were similar between groups; however, there was a trend of a lower incidence of early biopsy-proven acute rejection with anti-thymocyte globulin. Overall infection and cytomegalovirus infection were significantly lower in anti-thymocyte globulin-treated patients, and there was no increased incidence of hepatitis C recurrence in comparison with controls. In conclusion, delayed initiation of calcineurin inhibitor with anti-thymocyte globulin in liver transplant recipients is safe and is associated with improvements in renal function and a lower incidence of early acute rejection in comparison with no antibody and early initiation of calcineurin inhibitor.

Acute renal dysfunction in liver diseases

Renal dysfunction is common in liver diseases, either as part of multiorgan involvement in acute illness or secondary to advanced liver disease. The presence of renal impairment in both groups is a poor prognostic indicator. Renal failure is often multifactorial and can present as pre-renal or intrinsic renal dysfunction. Obstructive or post renal dysfunction only rarely complicates liver disease. Hepatorenal syndrome (HRS) is a unique form of renal failure associated with advanced liver disease or cirrhosis, and is characterized by functional renal impairment without significant changes in renal histology. Irrespective of the type of renal failure, renal hypoperfusion is the central pathogenetic mechanism, due either to reduced perfusion pressure or increased renal vascular resistance. Volume expansion, avoidance of precipitating factors and treatment of underlying liver disease constitute the mainstay of therapy to prevent and reverse renal impairment. Splanchnic vasoconstrictor agents, such as terlipressin, along with volume expansion, and early placement of transjugular intrahepatic portosystemic shunt (TIPS) may be effective in improving renal function in HRS. Continuous renal replacement therapy (CRRT) and molecular absorbent recirculating system (MARS) in selected patients may be life saving while awaiting liver transplantation.

The impact of aprotinin on renal function after liver transplantation: an analysis of 1,043 patients

Renal dysfunction is frequently seen after orthotopic liver transplantation (OLT). Aprotinin is an antifibrinolytic drug which reduces blood loss during OLT. Recent studies in cardiac surgery suggested a higher risk of postoperative renal complications when aprotinin is used. The impact of aprotinin on renal function after OLT, however, is unknown. In 1,043 adults undergoing OLT, we compared postoperative renal function in patients who received aprotinin (n = 653) or not (n = 390). Using propensity score stratification (C-index 0.82) and multivariate regression analysis, aprotinin was identified as a risk factor for severe renal dysfunction within the first week, defined as increase in serum creatinine by >or= 100% (OR = 1.97, 95% CI = 1.14-3.39; p = 0.02). No differences in renal function were noted at 30 and 365 days postoperatively. Moreover, no significant differences were found in the need for renal replacement therapy (OR = 1.52, 95% CI = 0.94-2.46; p = 0.11) or in 1-year patient survival rate (OR = 1.14, 95% CI = 0.73-1.77; p = 0.64) in patients who received aprotinin or not. In conclusion, aprotinin is associated with a higher risk of transient renal dysfunction in the first week after OLT, but not with a higher need for postoperative renal replacement therapy or an increased risk of mortality.

A novel prognostic model based on serum levels of total bilirubin and creatinine early after liver transplantation

BACKGROUND/AIM

We aim to evaluate the impact of early renal dysfunction (ERD), early allograft dysfunction (EAD) on post-transplant mortality, and further explore a simple and accurate model to predict prognosis.

PATIENTS

A total of 161 adult patients who underwent liver transplantation for benign end-stage liver diseases were enrolled in the retrospective study. Another 38 patients were used for model validation.

RESULTS

Poor patient survival was associated with ERD or EAD. A post-transplant model for predicting mortality (PMPM) based on serum levels of total bilirubin and creatinine at 24-h post-transplantation was then established according to multivariate logistic regression. At 3 months, 6 months and 1 year, the area under receiver operating characteristic curves (AUC) of PMPM score at 24-h post-transplantation (0.876, 0.878 and 0.849, respectively) were significantly higher than those of pre-transplant model for end-stage liver diseases (MELD) score (0.673, 0.674 and 0.618, respectively) or the post-transplant MELD score at 24-h post-transplantation (0.787, 0.787 and 0.781, respectively) (P<0.05). Patients with PMPM score <or=-1.4 (low-risk group, n=114) achieved better survival than those with PMPM score >-1.4 (high-risk group, n=47) (P<0.001). The patients in the high-risk group showed a relatively good outcome if their PMPM scores decreased to <or=-1.4 at post-transplant day 7. The subsequent validation study showed that PMPM functioned with a predictive accuracy of 100%.

CONCLUSION

The PMPM score could effectively predict short- and medium-term mortality in liver transplant recipients.

Acute renal disease, as defined by the RIFLE criteria, post-liver transplantation

Acute renal failure (ARF) can complicate up to 60% of orthotopic liver transplants (OLT). The RIFLE criteria were developed to provide a consensus definition for acute renal disease in critically ill patients. Using the RIFLE criteria, we aimed to determine the incidence and risk factors for ARF and acute renal injury (ARI), and to evaluate the link with the outcomes, patient survival and length of hospital stay. Three hundred patients, who received 359 OLTs, were retrospectively analyzed. ARI and ARF occurred post 11.1 and 25.7% of OLTs, respectively. By multivariate analysis, ARI was associated with pre-OLT hypertension and alcoholic liver disease and ARF with higher pre-OLT creatinine, inotrope and aminoglycoside use. ARF, but not ARI, had an impact on 30-day and 1-year patient survival and longer length of hospital stay. ARI and ARF, as defined by the RIFLE criteria, are common complications of OLT, with distinct risk factors and ARF has serious clinical consequences. The development of a consensus definition is a welcome advance, however these criteria do need to be validated in large studies in a wide variety of patient populations.

Clinical consequences of red cell storage in the critically ill

Red cell (RBC) transfusions are a potentially life-saving therapy employed during the care of many critically ill patients to replace losses in hemoglobin to maintain oxygen delivery to vital organs. During storage, RBCs undergo a series of biochemical and biomechanical changes that reduce their survival and function. Additionally, accumulation of other biologic by-products of RBC preservation may be detrimental to recipients of blood transfusions. Laboratory studies and an increasing number of observational studies have raised the possibility that prolonged RBC storage adversely affects clinical outcomes. In this article, the laboratory and animal experiments evaluating changes to RBCs during prolonged storage are reviewed. Subsequently, the clinical studies that have evaluated the clinical consequences of prolonged RBC storage are reviewed. These data suggest a possible detrimental clinical effect associated with the transfusion of stored RBCs; randomized clinical trials further evaluating the clinical consequences of transfusing older stored RBCs are required.