Preoperative characteristics and intraoperative transfusion and vasopressor requirements in patients with low vs. high MELD scores

Coagulopathy management in liver transplantation

Risk of bleeding and transfusion in liver transplantation is determined by age, severity of liver disease, as well as hemoglobin and plasma fibrinogen values. During the hepatectomy and the anhepatic phase, the coagulopathy is related to a decrease in clotting factors caused by surgical bleeding, facilitated by the increased portal hypertension and esophageal-gastric venous distension. Corrections of hematologic disturbances by administration of large volumes of crystalloid, colloid, or blood products may worsen the coagulopathy. Also, impaired clearance of fibrinolytic enzymes released from damaged cells can lead to primary fibrinolysis. At time of graft reperfusion further deterioration may occur as characterized by global reduction among all coagulation factors, decreased plasminogen activator inhibitor factors, and simultaneous generation of tissue plasminogen activator. In situations with inherent risk of bleeding, hypofibrinogenemia must be corrected. Concern about unwanted events is a major limitation of preventive therapy. There is some evidence for the efficacy of antifibrinolytic drugs to reduce red blood cell requirements. A guide for antifibrinolytic therapy are clot firmness in trhomboelastometry or alternatively, diffuse bleeding associated to a fibrinogen value less than 1 g/L. Because thrombin generation is limited in severe thrombocytopenia, platelet administration is recommended when active bleeding coexists with a platelet count below 50,000/mm(3). When the administration of hemoderivates and antifibrinolytic drugs does not correct severe bleeding, consumption coagulopathy and secondary fibrinolysis should be suspected. Treatment of affected patients should be based upon correcting the underlying cause, mostly related to tissue hypoxia due to critical hypoperfusion.

Storage age of transfused red blood cells during liver transplantation and its intraoperative and postoperative effects

BACKGROUND

Recent studies suggest that the storage age of red blood cells (RBCs) may be associated with morbidity and mortality in surgical patients. We studied perioperative effects of RBC storage age in patients undergoing orthotopic liver transplant (OLT).

METHODS

Adult patients who received ≥ 5 U of RBCs during OLT between January 2004 and June 2009 were studied. The subjects were divided into two groups according to the mean storage age of RBCs they received: new or old RBCs (stored ≤ 14 or >14 days, respectively). Effects of storage age of transfused RBCs during OLT on intraoperative potassium (K(+)) concentrations, incidence of hyperkalemia (K(+) ≥ 5.5 mmol/L), postoperative morbidity, and patient and graft survival were studied.

RESULTS

The mean serum K(+) concentrations and the incidence of hyperkalemia during OLT were significantly associated with storage age of the RBCs. Logistic analysis showed that storage age of RBCs was an independent risk factor for intraoperative hyperkalemia (odds ratios 1.067-1.085, p < 0.001) in addition to baseline K(+) concentration and units of RBCs transfused. Patient and graft survival and postoperative morbidity including postoperative ventilation, reoperation, acute renal dysfunction defined by the RIFLE criteria was not associated with old RBCs.

CONCLUSIONS

Transfusion of RBCs stored for a longer time was associated with intraoperative hyperkalemia but not with postoperative adverse outcomes in adult OLT. Prevention and treatment of potentially harmful hyperkalemia should be considered when old RBCs are administered.

A high model for end-stage liver disease score should not be considered a contraindication to living donor liver transplantation

OBJECTIVE

To analyze the outcomes of patients with high Model for End-Stage Liver Disease (MELD) scores who underwent adult-to-adult live donor liver transplantation (A-A LDLT).

MATERIALS AND METHODS

From September 2002 to October 2010, a total of 152 adult patients underwent A-A LDLT in our institution. Recipients were stratified into a low MELD score group (Group L; MELD score≤30) and a high MELD score group (Group H; MELD score>30) to compare short-term and long-term outcomes.

RESULTS

Of the 152 adult patients who underwent A-A LDLT, 9 were excluded from the analysis because they received ABO-incompatible grafts. Group H comprised 23 and Group L 120 patients. The median follow-up was 21.5 months (range, 3 to 102 m). The mean MELD score was 15.6 in Group L and 36.7 in Group H. There were no significant differences in the mean length of stay in the intensive care unit (Group L: 3.01 days vs Group H: 3.09 days, P=.932) or mean length of hospital stay (Group L: 17.89 days vs. Group H: 19.91 days, P=0.409). There were no significant differences in 1-, 3-, or 5-year survivals between patients in Groups L versus H (91.5% vs 94.7%; 86.4% vs 94.7%; and 86.4% vs 94.7%; P=.3476, log rank).

CONCLUSION

The short-term and long-term outcomes of patients with high MELD scores who underwent A-A LDLT were similar to those of patients with low MELD scores. Therefore, we suggest that high MELD scores are not a contraindication to LDLT.

Left lobe adult-to-adult living donor liver transplantation: Should portal inflow modulation be added?

Recently, the successful application of portal inflow modulation has led to renewed interest in the use of left lobe grafts in adult-to-adult living donor liver transplantation (LDLT). However, data on the hepatic hemodynamics supporting portal inflow modulation are limited, and the optimal portal circulation for a liver graft is still unclear. We analyzed 42 consecutive adult-to-adult left lobe LDLT cases without splenectomy or a portocaval shunt. The mean actual graft volume (GV)/recipient standard liver volume (SLV) ratio was 39.8% ± 5.7% (median = 38.9%, range = 26.1%-54.0%). The actual GV/SLV ratio was less than 40% in 24 of the 42 cases, and the actual graft-to-recipient weight ratio was less than 0.8% in 17 of the 42 recipients. The mean portal vein pressure (PVP) was 23.9 ± 7.6 mm Hg (median = 23.5 mm Hg, range = 9-38 mm Hg) before transplantation and 21.5 ± 3.6 mm Hg (median = 22 mm Hg, range = 14-27 mm Hg) after graft implantation. The mean portal pressure gradient (PVP - central venous pressure) was 14.5 ± 6.8 mm Hg (median = 13.5 mm Hg, range = 3-26 mm Hg) before transplantation and 12.4 ± 4.4 mm Hg (median = 13 mm Hg, range = 1-21 mm Hg) after graft implantation. The mean posttransplant portal vein flow was 301 ± 167 mL/minute/100 g of liver in the 38 recipients for whom it was measured. None of the recipients developed small-for-size syndrome, and all were discharged from the hospital despite portal hyperperfusion. The overall 1-, 3-, and 5-year patient and graft survival rates were 100%, 97%, and 91%, respectively. In conclusion, LDLT with a left liver graft without splenectomy or a portocaval shunt yields good long-term results for adult patients with a minimal donor burden.

Preoperative factors as predictors of blood product transfusion requirements in orthotopic liver transplantation

CONTEXT

Intraoperative transfusion can affect the chance of graft survival in liver transplantation, a complicated operation with massive blood loss. Verification of factors that are predictive of intraoperative blood loss and transfusion increases the quality of anesthesia management.

OBJECTIVE

To assess use of blood and blood products between 2002 and 2008 and to evaluate factors associated with blood loss and requirement for blood products in adult patients undergoing orthotopic liver transplantation via piggyback technique.

DESIGN

Medical charts and anesthesia records from 261 eligible adult recipients of an orthotopic liver transplant between March 2002 and May 2008 were reviewed.

SETTING

Shiraz Liver Transplantation Center, the only active liver transplantation center in Iran.

MAIN OUTCOME MEASURES

Potential influencing factors in blood loss and transfusion, including sex, preoperative hemoglobin level, international normalized ratio, primary diagnosis, platelet count, creatinine level, Model for End-Stage Liver Disease (MELD) score, central venous pressure, and total anesthesia time, were measured and subjected to multivariable analysis.

RESULTS

Mean blood loss was 54.2 (SD, 47.9) mL/kg, the mean (SD) for amounts of blood products transfused was 25.3 (19.5) mL/kg for packed red blood cells, 2.6 (3.3) units for fresh frozen plasma, and 1.7 (3.1) units for platelets. Seven recipients (2.7%) underwent transplantation without intraoperative transfusion of red blood cells, whereas 25 patients (9.6%) received more than 10 units of red blood cells intraoperatively. Multivariable analysis showed that no preoperative factor was a predictor of blood loss or requirement for intraoperative transfusion. Transfusion of fresh frozen plasma and packed red blood cells was significantly lower in 2005, 2006, 2007, and 2008 than in 2003 to 2004 (P < .001).

Risk factors for bleeding and transfusion during orthotopic liver transplantation

OBJECTIVE

While orthotopic liver transplantation (OLT) can be associated with haemorrhage, the risk factors for bleeding and transfusion remain difficult to predict. Perioperative transfusion has potentially deleterious side effects and impairs graft and patient survival. Preoperative identification of patients at high risk of bleeding is of clinical interest to manage perioperative transfusion and blood product storage.

STUDY DESIGN

Retrospective study.

PATIENTS AND METHODS

All OLT conducted between 2004 and 2008 in the University Hospital of Bordeaux were studied. Risk factors for bleeding greater than one blood volume and for massive red blood cell (RBC) transfusion were determined using univariate and multivariate analysis. Thresholds were determined with ROC curve analysis.

RESULTS

One hundred and forty-eight transplantations were studied. Preoperative haemoglobin and Child class A were independent protective risk factors for bleeding greater than one blood volume (OR 0.81 [0.67-0.98] and 0.27 [0.10-0.72], respectively). Preoperative Hb was a protective risk factor (OR 0.71 [0.58-0.88]) whereas history of oesophageal varicose bleeding was a risk factor (OR 4.67 [1.45-15.05]) for transfusion of more than eight RBC.

CONCLUSION

Risk factors for bleeding and transfusion during OLT identified in this study were of little clinical usefulness so blood products should always be available during the procedure.

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.

Prediction of graft dysfunction based on extended criteria donors in the model for end-stage liver disease score era

BACKGROUND

To explain the influence of recipient status combined with the accumulation of extended criteria donor (ECD) variables on the appearance of severe ischemia-reperfusion injury and graft survival in a model for end-stage liver disease (MELD)-based system, we analyzed our most recent consecutive liver transplantations (LTs), dividing them into two periods: 400 LTs (1992-2002; pre-MELD era) and 275 LTs (2002-2007; post-MELD era).

METHODS

Primary dysfunction (PD) was defined as primary graft failure that required emergency retransplantation or as initial poor function. Donor variables were included in a regression model to assess the probability of PD.

RESULTS

Donor age, macrovesicular steatosis more than 30%, and cold ischemia time were associated with allograft dysfunction. Mean probability of PD was 14.8%, 19.2%, 27.5%, and 37.4% for ECD 0, 1, 2, and more than or equal to 3, respectively (P=0.003). Distribution of no-mild, moderate, and severe ischemia-reperfusion injuries among MELD categories was 72.53%, 24.17%, and 3.30% (MELD group=12-19); 56.52%, 36.96%, and 6.5% (MELD group=20-28); and 23.91%, 54.35%, and 21.74% (MELD group >or=29), respectively (P=0.043). The development of PD according to ECD variables was 18.8%, 18.1%, 28.0%, and 35.3% for ECD 0, 1, 2, and more than or equal to 3, respectively (P=0.047). These variables were independent predictors of PD (Cox proportional regression model): ECD 2 (relative risk [RR]=1.59; 95% confidence interval [CI]=1.25-1.62), ECD 3 (RR=2.74; 95% CI=2.38-3.13), MELD 21 to 30 (RR=1.89; 95% CI=1.32-2.06), and MELD more than or equal to 30 (RR=3.38; 95% CI=2.43-3.86). Graft survival decreased, whereas MELD and the number of ECD variables increased.

CONCLUSION

The combination of three or more ECD variables and an MELD more than or equal to 29 is the worst scenario for graft success after LT.

Sluggish decline in a post-transplant model for end-stage liver disease score is a predictor of mortality in living donor liver transplantation

Background

The pre-transplant model for end-stage liver disease (pre-MELD) score is controversial regarding its ability to predict patient mortality after liver transplantation (LT). Prominent changes in physical conditions through the surgery may require a post-transplant indicator for better mortality prediction. We aimed to investigate whether the post-transplant MELD (post-MELD) score can be a predictor of 1-year mortality.

Methods

Perioperative variables of 269 patients with living donor LT were retrospectively investigated on their association with 1-year mortality. Post-MELD scores until the 30th day and their respective declines from the 1st day post-MELD score were included along with pre-MELD, acute physiology and chronic health evaluation (APACHE) II, and sequential organ failure assessment (SOFA) scores on the 1st post-transplant day. The predictive model of mortality was established by multivariate Cox's proportional hazards regression.

Results

The 1-year mortality rate was 17% (n = 44), and the leading cause of death was graft failure. Among prognostic indicators, only post-MELD scores after the 5th day and declines in post-MELD scores until the 5th and 30th day were associated with mortality in univariate analyses (P < 0.05). After multivariate analyses, declines in post-MELD scores until the 5th day of less than 5 points (hazard ratio 2.35, P = 0.007) and prolonged mechanical ventilation ≥24 hours were the earliest independent predictors of 1-year mortality.

Conclusions

A sluggish decline in post-MELD scores during the early post-transplant period may be a meaningful prognostic indicator of 1-year mortality after LT.

Extended criteria donor and severe intraoperative glucose variability: association with reoperation for hemorrhage in liver transplantation

Reoperations for hemorrhage following liver transplantation (OLT) are commonly associated with increased morbidity and mortality. We sought to determine the incidence and risk factors for reoperation for hemorrhage among adult liver transplantations. We retrospectively analyzed 668 patients transplanted between January 2004 and November 2007. Within 30 days following transplantation one hundred eleven patients (16.6%) underwent 156 reoperations for hemorrhage, averaging 1.4 reoperations per patient. More than half of the reoperations occurred during the first 2 postoperative days. One-third of patients required 2 or more reoperations. Multivariate logistic regression analysis showed 4 independent risk factors: grafts from donors with multiple extended criteria, severe intraoperative glucose variability, intraoperative use of vasopressors, and red blood cell transfusion requirement. In conclusion, we identified several independent risk factors for reoperation due to hemorrhage following OLT. Avoidance of severe intraoperative glucose variability and careful evaluation of the benefits and risks of utilizing extended criteria donors must be considered before transplantation.

Insulin therapy in divided doses coupled with blood transfusion versus large bolus doses in patients at high risk for hyperkalemia during liver transplantation

OBJECTIVE

To assess the effectiveness of an insulin regimen in divided doses designed to target risk factors of hyperkalemia in patients undergoing liver transplantation.

DESIGN

Retrospective comparison of the divided insulin dose regimen with a conventional large-bolus insulin method during liver transplantation.

SETTING

University-based, academic, tertiary center.

PARTICIPANTS

Adult patients whose baseline potassium levels were >/=4.0 mmol/L and received insulin therapy during liver transplantation at the authors' medical center between January 2004 and April 2007.

INTERVENTIONS

Insulin was administered either in divided doses (1-2 units) for each unit of red blood cells transfused or in a large-bolus in patients at high risk for hyperkalemia during liver transplantation.

MEASUREMENTS AND MAIN RESULTS

Among 717 patients who underwent liver transplantation, 50 patients received insulin in divided doses, and 101 patients received a large-bolus of insulin. Perioperative characteristics were comparable except for higher insulin doses in the large-bolus group. The divided insulin regimen was associated with significantly lower mean potassium levels within 2 hours before reperfusion of the graft compared with the conventional group (p < 0.005). The mean glucose levels in the divided group were significantly lower in both the pre- and postreperfusion periods than in the conventional group (p < 0.05 to <0.001).

CONCLUSIONS

The divided insulin dose regimen that specifically targets the risk factors for prereperfusion hyperkalemia is associated with significantly lower prereperfusion potassium and pre- and postreperfusion glucose levels and provides a useful alternative to the conventional large-bolus method in management of intraoperative hyperkalemia during liver transplantation.

Model for end-stage liver disease score predicts left ventricular assist device operative transfusion requirements, morbidity, and mortality

BACKGROUND

The Model for End-Stage Liver Disease (MELD) predicts events in cirrhotic subjects undergoing major surgery and may offer similar prognostication in left ventricular assist device candidates with comparable degrees of multisystem dysfunction.

METHODS AND RESULTS

Preoperative MELD scores were calculated for subjects enrolled in the University of Michigan Health System (UMHS) mechanical circulatory support database. Univariate and multiple regression analyses were performed to investigate the ability of patient characteristics, laboratory data (including MELD scores), and hemodynamic measurements to predict total perioperative blood product exposure and operative mortality. The ability of preoperative MELD scores to predict operative mortality was evaluated in subjects enrolled in the Interagency Registry of Mechanically Assisted Circulatory Support (INTERMACS), and results were compared with those from the UMHS cohort. The mean+/-SD MELD scores for the UMHS (n=211) and INTERMACS (n=324) cohorts were 13.7+/-6.1 and 15.2+/-5.8, respectively, with 29 (14%) and 19 (6%) perioperative deaths. In the UMHS cohort, median total perioperative blood product exposure was 74 units (25th and 75th percentiles, 44 and 120 units). Each 5-unit MELD score increase was associated with 15.1+/-3.8 units (beta+/-SE) of total perioperative blood product exposure. Each 10-unit increase in total perioperative blood product exposure increased the odds of operative death (odds ratio, 1.05; 95% confidence interval, 1.01 to 1.10). Odds ratios, measuring the ability of MELD scores to predict perioperative mortality, were 1.5 (95% confidence interval, 1.1 to 2.0) and 1.5 (95% confidence interval, 1.1 to 2.1) per 5 MELD units for the UMHS and INTERMACS cohorts, respectively. When MELD scores were dichotomized as >or=17 and <17, risk-adjusted Cox proportional-hazard ratios for 6-month mortality were 2.5 (95% confidence interval, 1.2 to 5.3) and 2.5 (95% confidence interval, 1.1 to 5.4) for the UMHS and INTERMACS cohorts, respectively.

CONCLUSIONS

The MELD score identified left ventricular assist device candidates at high risk for perioperative bleeding and mortality.

[The application of MELD score in patients submitted to liver transplantation: a retrospective analysis of survival and the predictive factors in the short and long term]

BACKGROUND

The model for end-stage liver disease (MELD) was developed to predict short-term mortality in patients with cirrhosis. There are few reports studying the correlation between MELD and long-term posttransplantation survival.

AIM

To assess the value of pretransplant MELD in the prediction of posttransplant survival.

METHODS

The adult patients (age >18 years) who underwent liver transplantation were examined in a retrospective longitudinal cohort of patients, through the prospective data base. We excluded acute liver failure, retransplantation and reduced or split-livers. The liver donors were evaluated according to: age, sex, weight, creatinine, bilirubin, sodium, aspartate aminotransferase, personal antecedents, brain death cause, steatosis, expanded criteria donor number and index donor risk. The recipients' data were: sex, age, weight, chronic hepatic disease, Child-Turcotte-Pugh points, pretransplant and initial MELD score, pretransplant creatinine clearance, sodium, cold and warm ischemia times, hospital length of stay, blood requirements, and alanine aminotransferase (ALT >1,000 UI/L = liver dysfunction). The Kaplan-Meier method with the log-rank test was used for the univariable analyses of posttransplant patient survival. For the multivariable analyses the Cox proportional hazard regression method with the stepwise procedure was used with stratifying sodium and MELD as variables. ROC curve was used to define area under the curve for MELD and Child-Turcotte-Pugh.

RESULTS

A total of 232 patients with 10 years follow up were available. The MELD cutoff was 20 and Child-Turcotte-Pugh cutoff was 11.5. For MELD score > or =20, the risk factors for death were: red cell requirements, liver dysfunction and donor's sodium. For the patients with hyponatremia the risk factors were: negative delta-MELD score, red cell requirements, liver dysfunction and donor's sodium. The regression univariated analyses came up with the following risk factors for death: score MELD > or = 25, blood requirements, recipient creatinine clearance pretransplant and age donor > or =50. After stepwise analyses, only red cell requirement was predictive. Patients with MELD score < 25 had a 68.86%, 50,44% and 41,50% chance for 1, 5 and 10-year survival and > or =25 were 39.13%, 29.81% and 22.36% respectively. Patients without hyponatremia were 65.16%, 50.28% and 41,98% and with hyponatremia 44.44%, 34.28% and 28.57% respectively. Patients with IDR > or =1.7 showed 53.7%, 27.71% and 13.85% and index donor risk <1.7 was 63.62%, 51.4% and 44.08%, respectively. Age donor > 50 years showed 38.4%, 26.21% and 13.1% and age donor < or =50 years showed 65.58%, 26.21% and 13.1%. Association with delta-MELD score did not show any significant difference. Expanded criteria donors were associated with primary non-function and severe liver dysfunction. Predictive factors for death were blood requirements, hyponatremia, liver dysfunction and donor's sodium.

CONCLUSION

In conclusion MELD over 25, recipient's hyponatremia, blood requirements, donor's sodium were associated with poor survival.

Liver donor's age and recipient's serum creatinine predict blood component use during liver transplantation

BACKGROUND

Excessive use of blood components during liver transplantation should be avoided because it has been associated with poor outcomes and it may stress blood bank resources.

STUDY DESIGN AND METHODS

To determine preoperative predictors of excessive transfusion requirements in patients undergoing liver transplantation, the clinical records of 126 consecutive adult patients undergoing primary liver transplantation were retrospectively reviewed. Outcome variables included number of red blood cells (RBCs), plasma, and plateletpheresis components intraoperatively transfused. Univariate analyses of the following predictor variables were performed: recipient age, sex, ethnicity, height/weight, Model for End Stage Liver Disease score, year of transplant, previous abdominal surgery, hepatoma, wait-list time, standard recipient laboratory values obtained immediately before transplantation, cold ischemia time, donor age, sex, and height/weight. Multivariate analysis using logistic regression was used to build a model that best predicted how many blood components should be available before transplant.

RESULTS

Donor age of more than 50 years old (odds ratio [OR], 2.8 95% confidence interval [CI], 1.3-6.0), and recipient serum creatinine (SCr) level of more than 1.3 mg/dL (OR, 3.8 95% CI, 1.6-8.9) were the only variables found to be predictive of RBC use in multivariate analysis. This model accurately predicted the use of more than 10 units of RBCs 79% of cases. Having both adverse factors present resulted in using more than one box in 80% of cases as compared to 44% of cases where only one or no adverse factor was present (p = 0.002). Further analyses showed a direct correlation between the number of RBCs transfused and plasma (r = 0.93) and plateletpheresis components (r = 0.74) transfused. [Corrections added after online publication 22-Jul-2009: OR updated from 3.8 to 2.8; CI from 1.6-8.9 to 1.3-6.0; OR from 2.8-3.8.]

CONCLUSION

Liver donor's age and recipient's SCr are important in preoperatively predicting blood use during liver transplantation.

MELD score and blood product requirements during liver transplantation: no link

BACKGROUND

Orthotopic liver transplantation has been traditionally associated with major blood loss and the need for allogenic blood product transfusions. In recent years, improvements in surgical and anesthetic techniques have greatly decreased the amount of blood products transfused. We have published a median of 0 for all intraoperative blood products transfused. Some authors argue that these results could be possible merely because of the relatively healthy cohort in terms of model of end-stage liver disease (MELD) score. The MELD score could be adjusted by some conditions (hepatocellular carcinoma, hemodialysis, hepatopulmonary syndrome, and amyloidosis) and was not adjusted in these series. The goal of this work was to verify the MELD score according to US standards and to find any link between the MELD score and the transfusion rate.

METHOD

Three hundred fifty consecutive liver transplantations were studied. The MELD score was adjusted according to US standards. Patients were divided into two groups according to the median of the MELD score. Blood loss and transfusion rate were determined for these two groups. Logistic regression models were used to find any link with transfusion of red blood cell (RBC) units.

RESULT

The MELD score before adjusting was 19+/-9 and 22+/-10 after. A mean of 0.5+/-1.3 RBC units/patient intraoperative were transfused with 80.6% of cases without any blood products. There was no difference for the blood loss (999+/-670 mL vs. 1017+/-885 mL) or the transfusion rate (0.4+/-1.2 vs. 0.5+/-1.4 RBC/patient) between two groups of MELD (<21 or >or=21) or any of its component (creatinine, bilirubin, and international normalized ratio). The logistic regression analysis found that only two variables were linked to RBC transfusion; starting hemoglobin value and phlebotomy.

CONCLUSION

In this series, the MELD score was as high as US series and did not predict blood losses and blood product requirement during liver transplantation. If the MELD system has to be implemented to prioritize orthotopic liver transplantation, it should be revisited, and the starting hemoglobin value should be added to the equation.

Improved outcome of adult recipients with a high model for end-stage liver disease score and a small-for-size graft

Although adult-to-adult living donor liver transplantation (ALDLT) has shown comparable outcomes to deceased donor liver transplantation, the outcome of patients with a high MELD score (>25) and a small-for-size graft (SFSG<0.8% of graft-to-recipient weight ratio) is not known. For 7 years, 167 consecutive hepatitis B virus-infected recipients underwent ALDLT at our institution. Based on their MELD score without additional score for hepatocellular carcinoma (HCC), the recipients were divided into Group L (low MELD score, n = 105) or Group H (high MELD score, n = 62). To analyze the risk of the graft size, the patients were further stratified as follows: Group Hs (high MELD score and SFSG, n = 11), Hn (high MELD score and normal size graft, n = 51), Ls (low MELD score and SFSG, n = 18), and Ln (low MELD score and normal size graft, n = 87). The primary endpoint was one-year patient survival rate (1-YSR). The mean follow-up period was 32.6 months. The mean MELD scores were 17.1 in Group L and 32.6 in Group H. Group H had more patients with the complications of cirrhosis but less patients with HCC than Group L (p < 0.05). However, major morbidity rates and 1-YSR were similar in comparisons between Group L (46.7% and 86.7%) and H (59.7% and 83.8%) (p > 0.05). 1-YSR was similar among Group Hs (72.7%), Hn (86.3%), Ls (83.3%), and Ln (88.5%) groups (p = 0.278). The multivariate analysis revealed accompanying HCC and the year of transplant were risk factors for poor 1-YSR. However, 1-YSR without HCC patients was also similar in comparisons between group L (90.2%) and H (91.7%) (p = 0.847), and among Group Hs (80.0%), Hn (94.7%), Ls (72.7%), and Ln (96.7%) (p = 0.072). In conclusion, high MELD score (>25) didn't predict 1-YSR in ALDLT. Improvement of the 1-YSR might be affected by center's experience as well as the selection of patients with low risk of recurrence of HCC.

The changing face of patients presenting for liver transplantation

PURPOSE OF REVIEW

Significant changes have been witnessed recently in patients presenting for liver transplantation. The growing number of liver transplantations performed, the increasingly successful outcomes, the expansion of indications, and the implementation of the Model for End-Stage Liver Disease (MELD) system are driving forces for those changes. The purpose of this review is to examine those changes and their effect in perioperative management.

RECENT FINDINGS

Patients who present for liver transplantation today have higher MELD scores and more advanced liver disease. Studies show that high MELD score patients are associated with high perioperative risks and undergo a more difficult perioperative course than patients with low MELD score. More specifically, they have more preoperative comorbidities, more baseline laboratory abnormalities, and higher requirements for intraoperative transfusion and vasopressors. Progress has been also made in management in patients with hepatocellular carcinoma, fulminant hepatic failure, and coronary artery disease prior to liver transplantation.

SUMMARY

Patients who present for liver transplantation today are more acutely ill compared with a few years ago and have more comorbidities, higher perioperative risks, and a more difficult perioperative course. Further characterization of the changes and associated perioperative risks and strategies to manage those risks are needed.

Changing trends in transfusion practice in liver transplantation

PURPOSE OF REVIEW

Prevention of excessive blood loss is an important issue in the perioperative management of liver transplantation. This review describes changing trends in blood products use, risk predicting of blood transfusion, variability in use and practices, as well as transfusion safety during liver transplantation.

RECENT FINDINGS

Over the last 20 years, the average use of blood products per case has considerably decreased. There are marked interinstitutional differences in blood use. Differences in patient population characteristics and surgical techniques are a partial explanation, but differences in transfusion practices probably account for a substantial part of the variability. Recent data have sparked off ongoing controversy relating to volume replacement therapy and its impact on blood loss. New studies emphasize the risks associated with transfusion in liver transplantation.

SUMMARY

Recent studies call for continuing every reasonable effort to minimize the use of blood components and can guide us in new approaches to this vital problem.

Anesthetic management of hepatic transplantation

PURPOSE OF REVIEW

The present review describes new trends and ongoing controversies in the anesthetic care of liver transplant recipients.

RECENT FINDINGS

Recent studies have improved our knowledge of conditions increasing perioperative risk, such as portopulmonary hypertension and renal failure. Improved surgical and anesthetic management has reduced intraoperative blood loss, as more studies identify an independent association between blood transfusion and poor outcome. New concepts in the coagulopathy of liver failure are emerging, with clear implications for clinical practice, including greater awareness of the risks of intraoperative thromboembolism. Less invasive intraoperative hemodynamic monitoring has been advocated, as has wider use of transoesophageal echocardiography. Early extubation is becoming more routinized.

SUMMARY

Anesthetic management still varies widely between liver transplant centers with little data to indicate best practice. Future research should focus on fluid replacement, prevention and treatment of coagulopathy, care of the acutely ill patient and the safety and benefits of early extubation.

The development of perioperative practices for liver transplantation: advances and current trends

Transplantation is a young medical specialty that has grown rapidly over the past 50 years. Anesthesiologists, surgeons and hepatologists are all essential partners in the process of determining patient outcome. Each specialty has made landmark improvements in patient outcome. However, there is still variability in practice patterns in each of the 3 major specialties. This review will use a historic perspective to explore the unique forces that shaped specific transplant practices and those that gave rise to differences in perioperative practices. Anesthesiologists and surgeons have made significant improvements in the management of blood loss, and coagulation monitoring and intervention. This has improved operative survival and early patient outcome. Perioperative survival has improved despite a worldwide shortage of donor organs and a trend to transplant sicker patients. A smaller pool of donor organs is required to meet the needs of an expanding waiting list. The innovations to reduce deaths on the transplant wait list are reviewed along with their impact on overall patient outcome. The evolving organ shortage is the pinnacle point in shaping future transplant practices. Currently, institutional-specific practices may be reinforced by the informal "tutorship" that is used to train physicians and by the resources available at each site of practice. However, there is evidence that specific intraoperative practices such as the use of a low central venous pressure, selection of vasopressors and certain surgical techniques can modify patient outcome. Further investigation is needed to determine whether the good or the bad associated with each practice prevails and in what unique circumstance.

Intraoperative massive transfusion decreases survival after liver transplantation

Patients undergoing liver transplantation often experience coagulopathy and massive intraoperative blood loss that can lead to morbidity and reduced survival. The aim of this study was to verify the survival rate and discover predictive factors for death among liver transplant patients who received massive intraoperative blood transfusions. This cohort study was based on prospective data collected retrospectively from January 2004 to July 2006. The 232 patients were distributed according to their blood requirements, (namely, more or less than 6 units), including red blood cell saver. The statistical analyses were performed using Student t test, Cox hazard regression, and the Kaplan-Meier method (log-rank test). The massively transfused cohort displayed higher Child-Pugh classifications (10.2 vs 9.6; P = .03); model for end-stage liver disease (MELD) scores (19 vs 17; P = .02); recipient weights (75.4 vs 71 kg; P = .03); as well as warm ischemia times (70.7 vs 56.4 minutes; P < .001) and surgery times (584.6 vs 503.4 minutes; P < .05). The proportional hazard (Cox) regression analysis showed that the risk of death increased 2.1% for each unit of donor sodium and 1.6% for each additional year of donors age over 50. The survival rates at 6, 12, 60, and 120 months for > or = 6 vs <6 U of blood transfusion of 63.8% vs 83.3%; 53.9% vs 76.3%; 40% vs 60%; 34.5% vs 49.2%. In conclusion, we observed that patients receiving over 6 red blood cell units intraoperatively displayed reduced survival. Predictive factors for this risk factor were high donor level of sodium and of age.

A multicenter evaluation of safety of early extubation in liver transplant recipients

Small single-institutional studies performed prior to the introduction of organ allocation using the Model for End-Stage Liver Disease (MELD) suggest that early airway extubation of liver transplant recipients is a safe practice. We designed a multicenter study to examine adverse events associated with early extubation in patients selected for liver transplantation using MELD score. A total of 7 institutions extubated all patients meeting study criteria and reported adverse events that occurred within 72 hours following surgery. Adverse events were uncommon: occurring in only 7.7% of 391 patients studied. Most adverse events were pulmonary or surgically related. Pulmonary complications were usually minor, requiring only an increase in ambient oxygen concentration. The majority of surgical adverse events required additional surgery. Analysis of a limited set of perioperative variables suggest that blood transfusions and technical factors were associated with an increased risk of adverse events. In conclusion, while early extubation appears to be safe under specified circumstances, there are performance differences between institutions that remain to be explained.

Acute renal failure after liver transplantation in MELD era

Model for End-Stage Liver Disease (MELD) score was used in our center from 2003 to assess the position of orthotopic liver transplantation (OLT) candidates on a waiting list. A key component of MELD score in the assessment of the degree of the illness is renal function. In this study, we measured the effects of this new scoring system on renal function and therapeutic strategies. We evaluated the incidence of acute renal function (ARF) after OLT requiring renal replacement therapy (hemofiltration or hemodialysis) in two patient groups: 240 transplanted before MELD era and 224 after the introduction of this parameter to select candidates. ARF occurred in 8.3% of patients in the pre-MELD group versus 13% in the MELD group, while the mortality rates were 40% and 27%, respectively. The creatinine level before OLT seemed to be a good predictor of ARF (P < .001), and blood transfusion rates (P < .05) as well as intraoperative diuresis (P < .05). In our analysis we did not observe a correlation between MELD score and postoperative ARF.

Predictors of hyperkalemia in the prereperfusion, early postreperfusion, and late postreperfusion periods during adult liver transplantation

BACKGROUND

Hyperkalemia poses serious hazards to patients undergoing orthotopic liver transplantation (OLT), and its predictors have not been thoroughly examined.

METHODS

We retrospectively studied 1124 consecutive adult patients who underwent OLT. Hyperkalemia was defined as serum K+ > or =5.5 mmol/L. A total of 47 recipient, donor, intraoperative, and laboratory variables were initially analyzed in univariate analyses. Independent predictors of hyperkalemia in three periods of OLT (prereperfusion, early postreperfusion, and late postreperfusion) were determined in multivariate logistic regression analyses.

RESULTS

Of 1124 patients, 10.2%, 19.1%, and 7.9% had hyperkalemia in the prereperfusion, early postreperfusion, and late postreperfusion periods, respectively. Higher baseline K+ and red blood cell transfusion were independent predictors of prereperfusion hyperkalemia. Higher baseline K+ (or prereperfusion K+) and donation after cardiac death donor were independent predictors of early postreperfusion hyperkalemia. Higher baseline K+, longer warm ischemia time, longer donor hospital stay, lower intraoperative urine output, and the use of venovenous bypass were independent predictors of late postreperfusion hyperkalemia.

CONCLUSIONS

Several laboratory, intraoperative, and donor variables were identified as independent predictors of hyperkalemia in the different periods. Such information may be used for more targeted preemptive interventions in patients who are at risk of developing hyperkalemia during adult OLT.

The model for end-stage liver disease (MELD)

The Model for End-stage Liver Disease (MELD) was initially created to predict survival in patients with complications of portal hypertension undergoing elective placement of transjugular intrahepatic portosystemic shunts. The MELD which uses only objective variables was validated subsequently as an accurate predictor of survival among different populations of patients with advanced liver disease. The major use of the MELD score has been in allocation of organs for liver transplantation. However, the MELD score has also been shown to predict survival in patients with cirrhosis who have infections, variceal bleeding, as well as in patients with fulminant hepatic failure and alcoholic hepatitis. MELD may be used in selection of patients for surgery other than liver transplantation and in determining optimal treatment for patients with hepatocellular carcinoma who are not candidates for liver transplantation. Despite the many advantages of the MELD score, there are approximately 15%-20% of patients whose survival cannot be accurately predicted by the MELD score. It is possible that the addition of variables that are better determinants of liver and renal function may improve the predictive accuracy of the model. Efforts at further refinement and validation of the MELD score will continue.

Ascites, but Not Hyponatremia, Is Associated With High Intraoperative Transfusion and Vasopressor Requirements During Liver Transplantation

BACKGROUND

We previously demonstrated that patients with high MELD scores required significantly higher volumes of blood transfusion and vasopressor usage during orthotopic liver transplantation (OLT) compared with patients with low MELD scores. Now we investigated whether hyponatremia or ascites were associated with increased transfusion and vasopressor requirements during OLT.

METHODS

Medical records of 192 OLT patients between January 1, 2004, and May 5, 2005, were retrospectively reviewed. Intraoperative transfusion of red blood cells (RBC) or fresh frozen plasma (FFP) and administration of vasopressors were compared.

RESULTS

As expected, patients with high (>30) MELD scores were associated with higher requirements for intraoperative transfusion and vasopressors than those with low (<or=30) MELD scores. Patients with or without hyponatremia (Na+> or <or=130) had similar requirements for transfusion and vasopressors. Patients with ascites had significantly higher requirements for both transfusion and vasopressors compared with those without (16.6+/-9.6 versus 11.8+/-9.0 for RBC; 22.0+/-11.0 versus 16.1+/-11.8 for FFP; and 60.2% versus 37.5% for vasopressors, P=.001 to .002). Patients with high (>30) MELD plus ascites scores (MELD+A, 4.5 points added to MELD if ascites was present) had higher requirements for transfusion and vasopressors compared with patients with low (<or=30) MELD+A scores (16.1+/-9.9 versus 11.4+/-8.6 for RBC; 21.7+/-12.7 versus 15.2+/- 9.6; and 63.4% versus 28.2% for vasopressors, P=.001 to <.001).

CONCLUSION

Although hyponatremia and ascites are indicators for liver disease severity, ascites, but not hyponatremia, is associated with increased intraoperative transfusion and vasopressor requirements during OLT.