Hyponatremia and mortality among patients on the liver-transplant waiting list

Management of refractory ascites and hepatorenal syndrome

One of the most common manifestations of the development of portal hypertension in the patient with cirrhosis is the appearance of ascites. Once ascites develops, the prognosis worsens and the patient becomes susceptible to complications such as bacterial peritonitis, hepatic hydrothorax, hyponatremia, and complications of diuretic therapy. As the liver disease progresses, the ascites becomes more difficult to treat and many patients develop renal failure. Most patients can be managed by diuretics which, when used correctly, will control the ascites. Spontaneous bacterial peritonitis can be treated effectively, but portends a worse prognosis. Once the ascites becomes refractory to diuretics, liver transplantation is the best option, although use of transjugular intrahepatic portosystemic shunts will control the ascites in many patients. Lastly, the development of hepatorenal syndrome indicates the patient's liver disease is advanced, and transplantation again is the best option. However, use of vasoconstrictors may improve renal function in some patients, helping in their management while they await a liver transplant.

Resting myocardial dysfunction in cirrhosis quantified by tissue Doppler imaging

BACKGROUND

Cirrhotic cardiomyopathy is described as latent cardiac failure. However, it remains to be investigated whether the myocardial dysfunction is present even at rest.

AIMS

The aim of the present study was to quantify left ventricular function at rest by means of tissue Doppler imaging in patients with cirrhosis and relate the findings to liver status and cirrhosis aetiology.

METHODS

Forty-four consecutive patients and 23 age-matched healthy controls were included. Conventional echocardiographic- and tissue Doppler-derived indices of systolic and diastolic function were obtained. Liver function was quantified by the galactose elimination capacity and clinical stage by the Child-Pugh and MELD scores.

RESULTS

Both systolic and diastolic myocardial functions were compromised in the patients at rest. Left ventricular ejection fraction (56.4 ± 6.1 vs. 59.9 ± 3.9%, P<0.02), mean peak systolic tissue velocity (4.6 ± 0.9 vs. 5.6 ± 0.7 cm/s, P<0.001) and mean systolic strain rate (-1.23 ± 0.19 vs. -1.5 ± 0.14/s, P<0.001) were all reduced in cirrhosis patients. Thirty-four patients (54%) had diastolic dysfunction, 11 had impaired diastolic relaxation pattern (25%), 12 had the more severe pseudonormal filling pattern (27%) and one had restrictive filling or severe diastolic dysfunction (2%). None of the echocardiographic findings were related to the cirrhosis aetiology.

CONCLUSION

Tissue Doppler imaging during rest detected substantial systolic and diastolic myocardial dysfunction in cirrhotic patients. This supports the existence of a distinct cirrhotic cardiomyopathy.

Intravenous fluid management for the acutely ill child

PURPOSE OF REVIEW

To review the principles of prescribing intravenous fluids (IVFs) to the acutely ill child and of adjusting sodium composition and fluid rate to prevent disorders in serum sodium or volume status from occurring.

RECENT FINDINGS

Recent data have revealed that the historic approach of administering hypotonic IVFs results in a high incidence of hospital-acquired hyponatremia in children. The majority of hospitalized children requiring IVFs are at risk for developing hyponatremia from numerous stimuli for arginine vasopressin (AVP) production, such as volume depletion, pain, stress, nausea, vomiting, respiratory or central nervous system (CNS) disorders, or the postoperative state. Multiple recent prospective studies in over 600 children have demonstrated that hypotonic fluids cause acute hyponatremia, whereas 0.9% sodium chloride (NaCl) effectively prevents it. 0.9% NaCl is the most appropriate IVF for the majority of hospitalized children. Fluid and sodium restriction will be needed for children with edematous or oliguric states and hypotonic fluids needed for children with urinary or extra-renal free water losses or hypernatremia.

SUMMARY

Hypotonic fluids should not be administered routinely in children due to the risk of hospital-acquired hyponatremia. 0.9% NaCl is the preferred IVF for the vast majority of hospitalized children.

[Hyponatremia in liver cirrhosis: pathogenesis and treatment]

Hyponatremia is the most common electrolyte disorder in patients with cirrhosis. This disorder can be a result of substantial loss of extracellular fluid "hypotonic or hypovolemic hyponatremia" or develop in the context of an increase in extracellular fluid volume and in the absence of major sodium losses; this situation occurs in patients with advanced cirrhosis and is known as "dilutional or hypervolemic hyponatremia". In dilutional or hypervolemic hyponatremia, serum sodium concentration is reduced, plasma volume is increased (although the effective plasma volume is decreased due to marked arterial vasodilation in the splanchnic circulation) and extracellular fluid volume is increased, with ascites and edema in the absence of signs of dehydration. This is a result of the marked deterioration in renal excretion of solute-free water, leading to disproportionate water retention in relation to sodium retention. Hypotonic hyponatremia represents 10% of all hyponatremias in patients with cirrhosis. Since hypervolemic hyponatremia is by far the most frequent form of this disorder, the present chapter will concentrate specifically on hypervolemic hyponatremia in cirrhosis.

Value of KCH criteria, MELD score and MELDNa score for prediction of prognosis of acute liver failure

AIM: To investigate the value of King's College Hospital (KCH) criteria, Model for End-stage Liver Disease (MELD) score and MELD with incorporation of serum sodium (MELDNa) score for evaluation of prognosis of acute liver failure.

METHODS: A total of 37 consecutive patients with acute liver failure (ALF) were included in the study and divided into two groups according to the prognosis. Areas under the receiver operating characteristic curve (AUC-ROC) of MELD, MELDNa and KCH criteria were used to assess the prognosis of patients with ALF.

RESULTS: The mortality of ALF was 70.3% in this study. MELD and MELDNa scores were significantly higher in the death group than in the survival group (43.8 ± 11.0 vs 31.0 ± 5.4, 43.4 ± 9.9 vs 32.1 ± 5.0, both P < 0.05). AUC-ROC of MELD score, MELDNa score and KCH criteria was 0.858 (0.704-0.950), 0.867 (0.715-0.955), and 0.645 (0.471-0.795), respectively. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and positive likelihood ratio (+LR) of MELD score were the same as those of MELDNa score but higher than those of KCH criteria (84.6 vs 65.4, 81.8 vs 63.6, 91.7 vs 81.0, 69.2 vs 43.7, 4.65 vs 1.80).

CONCLUSION: MELD, MELDNa scores and KCH criteria have appreciable value to evaluate the prognosis of ALF patients. MELD and MELDNa scores are more accurate than KCH criteria in assessing prognosis of ALF patients.

Liver transplantation in the high MELD era: a fair chance for everyone?

INTRODUCTION

In 2006, the model for end-stage liver disease (MELD) was introduced in Germany. Recent data clearly show a decrease of mortality on the waiting list but also a decrease of post-liver transplant survival. Several factors are discussed to be responsible for that; although, a MELD >30 is known to be major risk factor for outcome, MELD scores have increased to over 30 since introduction of the MELD system. On the other hand, the quality of donor organs is deteriorating from year to year at the same time.

RESULTS

To date, we have to face the dilemma of organ allocation to significantly sicker patients resulting in a noticeably worsening of post-orthotopic liver transplant (OLT) results. The question is how to keep an acceptable standard of post-OLT results.

CONCLUSION

Should allocation guidelines be modified? A further significant question is: How fair is the current allocation system for patients on the waiting list? Does the MELD score privileges or discriminates potential organ recipients?

Study of outcomes associated with hyponatremia and hypernatremia in children

Sodium is usually included in hospitals' critical values lists; however, the values at which sodium is considered to be life threatening (critical) vary among hospitals. Studies of outcomes associated with hyponatremia and hypernatremia in pediatric patients have not been published. We performed a retrospective chart review of sodium values of <124 mmol/L and >155 mmol/L that occurred during a 6-month period. Univariate and multivariate analyses for mortality risk were performed with the different variables. A total of 702 (1.32%) sodium tests fell in the study reference range, with 166 being <124 mmol/L and 536 being >155 mmol/L. Although not statistically significant, mortality was higher (38.5%) in patients with sodium values ≤ 120 mmol/L than in those with values ≥ 170 mmol/L (25%) or in patients with other values (<14%). Underlying conditions prevented assessment of morbidity associated with hyponatremia or hypernatremia. Treatment was instituted within 4 hours in 80% of cases (50% within 1 hour). Multivariate analysis showed increased risk of death for hyponatremic patients if they were premature or had heart abnormalities, while for hypernatremic patients the risk increased when other critical values were present. In conclusion, sodium levels of ≤ 120 mmol/L and ≥ 170 mmol/L have increased mortality in children; however, the risk of death is not statistically different when compared to risk in patients with milder hyponatremia and hypernatremia. Risk factors for death in hyponatremic and hypernatremic patients may primarily reflect the severity of the underlying conditions present in these children, such as prematurity and heart abnormalities, rather than the sodium derangement.

Gender, renal function, and outcomes on the liver transplant waiting list: assessment of revised MELD including estimated glomerular filtration rate

BACKGROUND & AIMS

The Model for End-Stage Liver Disease (MELD) allocation system for liver transplantation (LT) may present a disadvantage for women by including serum creatinine, which is typically lower in females. Our objectives were to investigate gender disparities in outcomes among LT candidates and to assess a revised MELD, including estimated glomerular filtration rate (eGFR), for predicting waiting list mortality.

METHODS

Adults registered for LT between 2002 and 2007 were identified using the UNOS database. We compared components of MELD, MDRD-derived eGFR, and the 3-month probability of LT and death between genders. Discrimination of MELD, MELDNa, and revised models including eGFR for mortality were compared using c-statistics.

RESULTS

A total of 40,393 patients (36% female) met the inclusion criteria; 9% died and 24% underwent LT within 3 months of listing. Compared with men, women had lower median serum creatinine (0.9 vs. 1.0 mg/dl), eGFR (72 vs. 83 ml/min/1.73 m(2)), and mean MELD (16.5 vs. 17.2; all p <0.0005), but within most MELD strata, had higher bilirubin and INR. After adjusting for relevant covariates including creatinine and body weight, women were less likely than men to receive a LT (hazard ratio [HR] 0.85; 95% CI 0.79-0.87) and had greater 3-month mortality (HR 1.13; 95% CI 1.05-1.21). Revision of MELD and MELDNa to include eGFR did not improve discrimination for 3-month mortality (c-statistics: MELD 0.896, MELD-eGFR 0.894, MELDNa 0.911, MELDNa-eGFR 0.905).

CONCLUSIONS

Women are disadvantaged under MELD potentially due to its inclusion of creatinine. However, since including eGFR in MELD does not improve mortality prediction, alternative refinements are necessary.

Outcome predictors of cirrhotic patients with spontaneous bacterial empyema

BACKGROUND

Spontaneous bacterial empyema (SBE) is a complication of cirrhotic patients in which a pre-existing pleural effusion becomes infected. This retrospective study was designed to investigate the bacteriology and outcome predictors of SBE in cirrhotic patients.

METHODS

Medical records of cirrhotic patients treated in a tertiary care university hospital from December 2004 to December 2008 were retrospectively reviewed.

RESULTS

Of 3390 cirrhotic patients seen during the study period, 81 cases of SBE were diagnosed. The incidence of SBE was 2.4% (81/3390) in cirrhotic patients and 16% (81/508) in patients with cirrhosis with hydrothorax. There were 46 monomicrobial infections found in 46 SBE patients. Aerobic Gram-negative organisms were the predominant pathogens (n=29, 63%), and Escherichia coli (n=9, 20%) was the most frequently isolated sole pathogen. The mortality rate of SBE was 38% (31/81). Univariate analysis showed that Child-Pugh score, model for end-stage liver disease (MELD)-Na score, concomitant bacteraemia, concomitant spontaneous bacterial peritonitis, initial intensive care unit (ICU) admission and initial antibiotic treatment failure were predictors of poor outcomes. Multivariate regression analysis demonstrated that the independent factors related to a poor outcome were initial ICU admission [odds ratio (OR): 4.318; 95% confidence interval 1CI) 1.09-17.03; P=0.037], MELD-Na score (OR: 1.267; 95% CI 1.08-1.49; P=0.004) and initial antibiotic treatment failure (OR: 13.10; 95% CI 2.60-66.03).

CONCLUSION

Spontaneous bacterial empyema in cirrhotic patients is a high mortality complication. The independent factors related to poor outcome are high MELD-Na score, initial ICU admission and initial antibiotic treatment failure. High MELD-Na score may be a useful mortality predictor of SBE in cirrhotic patients.

Is estimated glomerular filtration rate superior to serum creatinine in predicting mortality on the waiting list for liver transplantation?

Serum creatinine is an important prognostic indicator in patients on the liver transplant waiting-list, being a component of the Model for End Stage Liver Disease (MELD) score. However, creatinine is influenced by age, gender and race, and in this role may disadvantage some individuals. The Modification of Diet in Renal Disease (MDRD) estimated glomerular filtration rate (eGFR) takes into account these variables and may be a superior measure of renal function. Our aim was to examine whether the MDRD 4-variable, 5-variable and 6-variable eGFRs are superior to serum creatinine in predicting 3-month waiting-list mortality in patients with end-stage liver disease. This was a retrospective single-centre study of 427 adults listed for first liver transplantation. The median listing MDRD 4-variable, 5-variable and 6-variable eGFR was 69, 71 and 73 ml/min/1.73 m(2) , respectively. The median listing serum creatinine was 89 μm. MDRD 4-variable (P = 0.002), 5-variable (P < 0.001) and 6-variable eGFR (P < 0.001), and serum creatinine (P < 0.001), were all predictors of mortality on the transplant waiting-list. Of the three MDRD equations, the 6-variable eGFR was the better prognostic indicator. The substitution of 6-variable eGFR for serum creatinine did not improve the prognostic accuracy of the MELD (P = 0.825) and UK score for Patients with End-Stage Liver Disease (P = 0.781) scores. In conclusion the MDRD eGFR is comparable, but not superior to serum creatinine, in predicting death within 3 months of listing for liver transplantation.

Pre-transplant MELD and sodium MELD scores are poor predictors of graft failure and mortality after liver transplantation

BACKGROUND

Incorporating serum sodium concentrations into the model for end-stage liver disease (MELD) score may increase its sensitivity for identifying priority patients for orthotopic liver transplantation (OLT). We, therefore, evaluated and compared the ability of the sodium MELD and MELD scores to predict graft and patient survival after OLT.

METHODS

The United Network for Organ Sharing (UNOS) registry includes all US adult OLTs performed between January 2000 and August 2008. For 15,156 patients who met inclusion criteria, MELD score was calculated; for 6,193 patients whose serum sodium concentrations was between 120 and 135 mEq/dl, immediately before OLT, sodium MELD score was calculated. The corresponding hazard ratios (HR) for MELD and sodium MELD on graft and patient survival were assessed using the Cox proportional hazards regression models. The concordance probability estimate (CPE) was used to evaluate predictive ability of each time-to-event model.

RESULTS

MELD and sodium MELD scores were both significant predictors in univariable Cox regression models for graft failure [HR (95% CI) for every 10 units increase in the predictor: 1.10 (1.04, 1.17), P = 0.001, and 1.05 (1.00, 1.10), P = 0.03, respectively], and for mortality (1.14 (1.07, 1.21), P < 0.001, and 1.07 (1.02, 1.12), P = 0.01, respectively), with CPE of 0.52-0.53.

CONCLUSION

While MELD and sodium MELD were each significantly associated with survival after OLT, their predictive abilities were poor. The sodium MELD score does not improve prediction accuracy over the MELD score. Weak prediction may result from unaccounted variability in recipient and donor status, as well as surgical and postoperative factors.

Use of reclassification for assessment of improved prediction: an empirical evaluation

BACKGROUND

An increasing number of studies evaluate the ability of predictors to change risk stratification and alter medical decisions, i.e. reclassification performance. We examined the reported design and analysis of recent studies of reclassification and the robustness of their claims for improved reclassification.

METHODS

Two independent investigators searched PubMed and citations to the article that introduced the currently most popular reclassification metric (net reclassification index, NRI) to identify studies performing reclassification analysis (January 2006-January 2010). We focused on articles that included any analyses comparing the performance of a baseline predictive model vs the baseline model plus some additional predictor for a prospectively assessed outcome. We recorded information on the baseline model used, outcomes assessed, choice of risk thresholds and features of reclassification analyses.

RESULTS

Of 58 baseline models used in 51 eligible papers, only 14 (24%) were previously described, used as described and had same outcomes as originally intended. Calibration was examined in 53% of the studies. Sixteen studies (31%) provided a reference for the choice of risk thresholds and only six used the previously proposed categories or justified the use of alternative thresholds. Only 14 studies (27%) stated that the chosen risk thresholds had different therapeutic intervention implications. NRI was calculated in 38 studies and was smaller in studies with adequately referenced or justified risk thresholds vs others (P < 0.0001).

CONCLUSIONS

Reclassification studies would benefit from more rigorous methodological standards; otherwise claims for improved reclassification may remain spurious.

Prognostic importance of the cause of renal failure in patients with cirrhosis

BACKGROUND & AIMS

The prognostic value of the different causes of renal failure in cirrhosis is not well established. This study investigated the predictive value of the cause of renal failure in cirrhosis.

METHODS

Five hundred sixty-two consecutive patients with cirrhosis and renal failure (as defined by serum creatinine > 1.5 mg/dL on 2 successive determinations within 48 hours) hospitalized over a 6-year period in a single institution were included in a prospective study. The cause of renal failure was classified into 4 groups: renal failure associated with bacterial infections, renal failure associated with volume depletion, hepatorenal syndrome (HRS), and parenchymal nephropathy. The primary end point was survival at 3 months.

RESULTS

Four hundred sixty-three patients (82.4%) had renal failure that could be classified in 1 of 4 groups. The most frequent was renal failure associated with infections (213 cases; 46%), followed by hypovolemia-associated renal failure (149; 32%), HRS (60; 13%), and parenchymal nephropathy (41; 9%). The remaining patients had a combination of causes or miscellaneous conditions. Prognosis was markedly different according to cause of renal failure, 3-month probability of survival being 73% for parenchymal nephropathy, 46% for hypovolemia-associated renal failure, 31% for renal failure associated with infections, and 15% for HRS (P < .0005). In a multivariate analysis adjusted for potentially confounding variables, cause of renal failure was independently associated with prognosis, together with MELD score, serum sodium, and hepatic encephalopathy at time of diagnosis of renal failure.

CONCLUSIONS

A simple classification of patients with cirrhosis according to cause of renal failure is useful in assessment of prognosis and may help in decision making in liver transplantation.

Moderate ascites identifies patients with low model for end-stage liver disease scores awaiting liver transplantation who have a high mortality risk

Donor livers are offered to patients with the highest risk of death. How ascites could inform risk models to reduce liver transplant wait-list mortality is unclear. All adult candidates for primary liver transplantation for cirrhosis without exception points who were registered with the Organ Procurement and Transplantation Network from 2005 to 2007 composed our study cohort. Using Cox models and advanced discriminative metrics and paying attention to geographic disparities, we evaluated the additional risk discrimination of moderate ascites over that of the Model for End-Stage Liver Disease (MELD) or the Model for End-Stage Liver Disease plus serum sodium (MELD-Na) alone for the prediction of 90-day wait-list mortality. Additional analyses examined lower mortality risk candidates and those listed in high-demand, low-supply United Network for Organ Sharing regions in which accounting for ascites may most significantly affect wait-list mortality. Between 2005 and 2007, 18,124 subjects were listed for liver transplantation. Mortality was higher in patients with moderate ascites (15.4% versus 6.0%, P < 0.0001), and this risk persisted despite adjustments for MELD (hazard ratio = 1.58, 95% confidence interval = 1.42-1.76) and MELD-Na (hazard ratio = 1.42, 95% confidence interval = 1.28-1.58). The effect of moderate ascites was more prominent with a MELD score <21 (equal to 4.7 MELD units) or with a MELD-Na score <21 (equal to 3.5 MELD-Na units). Wait-list mortality was higher in patients with moderate ascites who were listed in high-demand, limited-supply regions (25.8% versus 17.5% at 1 year, P < 0.01). With the addition of moderate ascites, there was improvement in the overall risk model, particularly with a MELD score <21, as measured by the C index and integrated discrimination improvement. Moderate ascites informed risk prediction, particularly with a MELD score <21 and in high-demand, limited-supply regions. Under the MELD system, the presence of moderate ascites should prompt clinicians to consider strategies to expand access to transplantation, such as the use of extended donor liver grafts.

Mortality after surgery in patients with liver cirrhosis: comparison of Child-Turcotte-Pugh, MELD and MELDNa score

BACKGROUND/AIMS

This study was aimed at determining the postoperative mortality in patients with cirrhosis by Child-Turcotte-Pugh (CTP), Model for End-stage Liver Disease score (MELD), and Model for End-stage Liver Disease and Serum Sodium Concentration score (MELDNa) systems and to compare the predictability of the scoring systems.

METHODS

Analysis was performed on clinical records of 490 patients with cirrhosis who underwent surgery under general anesthesia from January 2003 to December 2008.

RESULTS

(i) Ninety-day mortality in patients with CTP A, B, and C class were 2.1, 22.1 and 54.5%, respectively. (ii) Ninety-day mortality according to MELD score was as follows: 6-9, 3.5%; 10-14, 8.9%; 15-19, 14.3%; 20-24, 12.5%; and ≥25, 63.6%. (iii) Ninety-day mortality according to MELDNa score was as follows: 6-9, 1.9%; 10-14, 6.2%; 15-19, 13.2%; 20-24, 20.6%; and ≥25, 50%. (iv) Multivariable analysis showed that emergency surgery, American Society of Anesthesiologist class ≥IV, CTP score ≥7, MELD score ≥10, and MELDNa score ≥10 were independent risk factors for 90-day mortality. (v) The area under the receiver operating curve of CTP, MELD, and MELDNa in predicting 90-day mortality were 0.859, 0.761, 0.818, and nonparametric approach using the generalized U-statistic showed that the CTP score was equal to the MELDNa score (P=0.855) and the CTP and MELDNa scores were superior to the MELD score (P=0.027 and 0.047) in predicting postoperative 90-day mortality.

CONCLUSION

Mortality according to the CTP, MELD, and MELDNa scoring systems were determined and all scoring systems predicted postoperative mortality in patients with cirrhosis. The CTP score and MELDNa score were superior to the MELD score in predicting postoperative 90-day mortality.

Influence of serum sodium on MELD-based survival prediction in alcoholic hepatitis

OBJECTIVE

To compare the Model for End-Stage Liver Disease (MELD) with the modified model including sodium (MELDNa) for predicting 180-day mortality in patients with alcoholic hepatitis (AH) and determine the subset in whom serum sodium may enhance 180-day mortality prediction.

PATIENTS AND METHODS

We examined 26 patients with AH enrolled in a prospective trial between June 1, 2004, and June 30, 2007, at Mayo Clinic. Logistic regression analysis was done to assess the effect of MELD and MELDNa scores on 180-day mortality. The C statistic was derived to compare MELD with MELDNa in patients with and without ascites.

RESULTS

MELD (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.05-1.47; P = .007; C statistic, 0.81) and MELDNa (OR, 1.24; 95% CI, 1.05-1.56; P = .008; C statistic, 0.78) were significant predictors of 180-day mortality in patients with AH. A MELD score of 27.0 and a MELDNa score of 28.0 had sensitivity of 76.5% and 87.5% and specificity of 64.9% and 52.5%, respectively. In patients with AH and ascites, MELDNa (OR, 2.27; 95% CI, 1.22-36.68; P = .008; C statistic, 0.97) was a better predictor of 180-day mortality than MELD (OR, 1.37; 95% CI, 1.07-2.12; P = .006; C statistic, 0.90). A MELD score of 29.0 and a MELDNa score of 34.0 had sensitivity of 85.7% and 83.3% and specificity of 31.0% and 16.7%, respectively.

CONCLUSION

MELD and MELDNa were similar predictors of 180-day mortality; however, MELDNa was a better predictor of mortality than MELD in patients with ascites. Hyponatremia in patients with AH without ascites is not a predictor of mortality because it may have a dilutional basis secondary to excessive intake of low-osmolar alcohol.

Mortality associated with low serum sodium concentration in maintenance hemodialysis

BACKGROUND

low serum sodium concentrations are associated with an increased risk of death in the general population, but causality is uncertain due to confounding from clinical conditions such as congestive heart failure and cirrhosis, in which hyponatremia results from elevated levels of arginine vasopressin.

METHODS

to examine the association between predialysis serum sodium concentration and mortality in patients undergoing hemodialysis for end-stage renal disease, a condition in which arginine vasopressin does not affect water excretion and osmoregulation, we studied 1549 oligoanuric participants in the HEMO study, a randomized controlled trial of hemodialysis patients examining the effect of hemodialysis dose and flux. We used proportional hazards models to compare the risk of death according to predialysis serum sodium concentration.

RESULTS

considered as a continuous variable, each 4-mEq/L increment in baseline predialysis serum sodium concentration was associated with a hazard ratio for all-cause mortality of 0.84 (95% confidence interval (CI), 0.78-0.90). Multivariable adjustment for demographic, clinical, laboratory, and dialysis-specific covariates, including ultrafiltration volume, did not appreciably change the results (hazard ratio for all-cause mortality of 0.89; 95% CI, 0.82-0.96). the results also were consistent in time-updated analyses using repeated measures of serum sodium and other relevant covariates.

CONCLUSION

Lower predialysis serum sodium concentration is associated with an increased risk of death. Considering the unique physiology in the dialysis population, these findings raise the possibility that hyponatremia itself may be a causal determinant of mortality in the broader population.

Perioperative mortality after non-hepatic general surgery in patients with liver cirrhosis: an analysis of 138 operations in the 2000s using Child and MELD scores

INTRODUCTION

Despite of advances in modern surgical and intensive care treatment, perioperative mortality remains high in patients with liver cirrhosis undergoing nonhepatic general surgery. In the few existing articles, mortality was reported to be as high as 70% in patients with poor liver function (high Child or model for end-stage liver disease (MELD) score). Since data are limited, we analyzed our recent experience with cirrhotic patients undergoing emergent or elective nonhepatic general surgery at a German university hospital.

METHODS

Since 2000, 138 nonhepatic general surgical procedures (99 intra-abdominal, 39 abdominal wall) were performed in patients with liver cirrhosis. Liver cirrhosis was preoperatively classified according to the Child (41 Child A, 59 B, 38 C) and the MELD score (MELD median 13). Sixty-eight (49%) of the patients underwent emergent operations. Most abdominal wall operations were for hernias. Intra-abdominal operations consisted of GI tract procedures (n=53), cholecystectomies (n=15), and various others (n=31). Perioperative data were gained by retrospective analysis.

RESULTS

Overall perioperative mortality in all 138 cases was 28% (9% in elective surgery, 47% in emergent surgery; p<0.001). Perioperative mortality was higher after intra-abdominal than after abdominal wall operations (35% vs. 8%; p=0.001) or in patients requiring transfusions (43% vs. 5% without transfusions; p<0.001). Perioperative mortality increased with the Child score (10% Child A, 17% Child B, 63% Child C; p<0.01) and the MELD score (9% MELD <10, 19% MELD 10–15, 54% MELD >15; p<0.001). Univariately, further factors like American Society of Anesthesiologists (ASA) score and various preoperative laboratory values were also associated with perioperative mortality. By multivariate analysis of all 138 operations, the Child and ASA classifications, intraoperative transfusions, and a preoperative sodium <130 mmol/l, but not the MELD score, were independent prognostic factors. Analysis of elective operations revealed only a preoperatively increased creatinine as risk factor for perioperative mortality. In emergent operations again, Child class, blood transfusions, and low sodium level, but not the MELD score, predicted postoperative mortality.

CONCLUSIONS

Our results demonstrate that perioperative mortality remains high in patients with liver cirrhosisundergoing general surgery, especially in emergent situations. Patients with poor liver function and/or need for blood transfusions even had a very high mortality. In our experience, the Child score (together with other variables) independently correlates with perioperative mortality in emergent operations whereas the MELD score was inferior in predicting the outcome.

Chemoembolization decreases drop-off risk of hepatocellular carcinoma patients on the liver transplant list

INTRODUCTION

The drop-off risk for patients awaiting liver transplantation for hepatocellular carcinoma (HCC) is 22%. Transplant liver availability is expected to worsen, resulting in longer waiting times and increased drop-off rates. Our aim was to determine whether chemoembolization can decrease this risk.

PATIENTS AND METHODS

Eighty-seven consecutive HCC patients listed for liver transplant (Milan criteria) underwent statistical comparability adjustments using the propensity score (Wilcoxon, Fisher's, and chi-square tests). Forty-three nonchemoembolization patients and 22 chemoembolization patients were comparable for Child-Pugh and Model for End-Stage Liver Disease scores, tumor size and number, alpha fetoprotein (AFP) levels, and cause of cirrhosis. We calculated the risk of dropping off the transplant list by assigning a transplant time to those who dropped off (equal probability with patients who were on the list longer than the patient in question). The significance level was obtained by calculating the simulation distribution of the difference compared with the permutations of chemoembolization versus nonchemoembolization assignment of the patients. Kaplan-Meier estimators (log-rank test) were used to determine survival rates.

RESULTS

Median follow-up was 187 ± 110 weeks (range 38 to 435, date of diagnosis). The chemoembolization group had an 80% drop-off risk decrease (15% nonchemoembolization versus 3% chemoembolization, p = 0.04). Although survival was better for the chemoembolization group, it did not reach statistical significance. Two-year survival for the nonchemoembolization and chemoembolization group was 57.3% ± 7.1% and 76.0% ± 7.9%, respectively (p = 0.078).

CONCLUSIONS

Chemoembolization appears to result in a significant decrease in the risk of dropping off liver transplant list for patients with HCC and results in a tendency toward longer survival.

Prioritization for liver transplantation

There are three possible policies for prioritization for liver transplantation: medical urgency, utility and transplant benefit. The first is based on the severity of cirrhosis, using Child-Turcotte-Pugh score and, more recently, the Model for End-stage Liver Disease (MELD) score, or variants of MELD, for allocation. Although prospectively developed and validated, the MELD score has several limitations, including interlaboratory variations for measurement of serum creatinine and international normalized ratio of prothrombin time, and a systematic adverse female gender bias. Adjustments to the original MELD equation and new scoring systems have been proposed to overcome these limitations; incorporation of serum sodium improves its predictive accuracy. The MELD score poorly predicts outcomes after liver transplantation due to the absence of donor factors incorporated into the scoring system. Several utility models are based on donor and recipient characteristics. Combined poor recipient and donor characteristics lead to very poor outcomes, which in a utility system would be considered unacceptable. Finally, transplant benefit models rank patients according to the net survival benefit that they would derive from transplantation. However, complex statistical models are required, and unmeasured characteristics may unduly affect the models. Well-designed prospective studies and simulation models are necessary to establish the optimal allocation system in liver transplantation.

Renal and circulatory dysfunction in cirrhosis: current management and future perspectives

Chronic liver diseases are amongst the top leading causes of death in Europe as well as in other areas of the world. Chronic liver diseases are characterized by unrelenting progression of liver inflammation and fibrosis over a prolonged period of time, usually more than 20 years, which may eventually lead to cirrhosis. Advanced cirrhosis leads to a complex syndrome of chronic liver failure which involves many different organs besides the liver, including the brain, heart and systemic circulation, adrenal glands, lungs, and kidneys. The high morbidity and mortality secondary to chronic liver failure is due to complications related to the dysfunction of these organs, either alone or, more frequently, in combination. Understanding the mechanisms leading to organ dysfunction is crucial to the development of strategies for treatment and prevention of complications of cirrhosis. This article reviews our current knowledge, as well as future perspectives, on the management of circulatory and renal dysfunction in chronic liver failure.

Diagnosis and management of chronic liver disease in older people

Chronic liver disease is increasingly prevalent and, as the population ages, geriatricians will see an increasing burden. We present an overview of the investigation and management of older adults with chronic parenchymal liver disease and highlight the potential roles of transjugular intrahepatic portosytemic shunts and orthotopic liver transplantation.

Hyponatremia in patients treated with terlipressin for severe gastrointestinal bleeding due to portal hypertension

Terlipressin is frequently used in acute variceal bleeding due to its powerful effect on vasopressin V1 receptors. Although terlipressin is also a partial agonist of renal vasopressin V2 receptors, its effects on serum sodium concentration have not been specifically investigated. To examine the effects of terlipressin on serum sodium concentration in patients with acute portal-hypertensive bleeding, 58 consecutive patients with severe portal-hypertensive bleeding treated with terlipressin were investigated. In the whole population, serum sodium decreased from 134.9 ± 6.6 mEq/L to 130.5 ± 7.7 mEq/L (P = 0.002). Thirty-nine patients (67%) had a decrease in serum sodium ≥ 5 mEq/L during treatment: in 18 patients (31%), between 5 and 10 mEq/L and in 21 patients (36%), greater than 10 mEq/L. In this latter group, serum sodium decreased from 137.2 ± 5 to 120.5 ± 5 mEq/L (P < 0.001). In multivariate analysis, the reduction in serum sodium was related to baseline serum sodium and Model for End-Stage Liver Disease (MELD) score; patients with low MELD and normal or near-normal baseline serum sodium had the highest risk of hyponatremia. Serum sodium returned to baseline values in most patients shortly after cessation of therapy. Three of the 21 patients with marked reduction in serum sodium developed neurological manifestations, including osmotic demyelination syndrome in one patient due to a rapid recovery of serum sodium (serum sodium in these three patients decreased from 135, 130, and 136 to 117, 114, and 109 mEq/L, respectively).

CONCLUSION

An acute reduction in serum sodium concentration is common during treatment with terlipressin for severe portal-hypertensive bleeding. It develops rapidly after start of therapy, may be severe in some patients and is associated with neurological complications, and is usually reversible after terlipressin withdrawal.

Pre-operative nomogram to predict risk of peri-operative mortality following liver resections for malignancy

INTRODUCTION

The majority of liver resections for malignancy are performed in older patient with major co-morbidities. There is currently no pre-operative, patient-specific method to determine the likely peri-operative mortality for each individual patient. The aim of this study was to develop a pre-operative nomogram based on the presence of co-morbidities to predict risk of peri-operative mortality following liver resections for malignancy.

METHODS

The Nationwide Inpatient Sample database was queried to identify adult patients that underwent liver resection for malignancy. The pre-operative co-morbidities, identified as predictors were used and a nomogram was created with multivariate regression using Taylor expansion method in SAS software, surveylogistic procedure. Training set (years 2000-2004) was utilized to develop the model and validation set (year 2005) was utilized to validate this model.

RESULTS

A total of 3,947 and 972 patients were included in training and validation sets, respectively. The overall actual-observed peri-operative mortality rates for training and validation sets were 4.1% and 3.2%, respectively. The decile-based calibration plots for the training set revealed good agreement between the observed probabilities and nomogram-predicted probabilities. Similarly, the quartile-based calibration plot for the validation set revealed good agreement between the observed and predicted probabilities. The accuracy of the nomogram was further reinforced by a good concordance index of 0.80 with a 95% confidence interval of 0.72 and 0.87.

CONCLUSIONS

This pre-operative nomogram may be utilized to predict the risk of peri-operative mortality following liver resection for malignancy.

Vasopressin-receptor antagonists

Despite a crucial role in body fluid homeostasis, elevated vasopressin levels can also be pathological in conditions such as congestive heart failure, liver cirrhosis and the syndrome of inappropriate antidiuretic hormone secretion. The result of elevated vasopressin is renal water retention and hyponatremia, a low serum sodium concentration. Hyponatremia is associated with excess morbidity and mortality. Nonpeptide vasopressin-receptor antagonists represent a new drug class of small molecules that competitively inhibit one or more of the vasopressin receptors. There are three vasopressin receptors in humans, including V1a, V1b and V2. Selective V2- and combined V1a/V2-receptor antagonists have been developed for the treatment of hyponatremia resulting from congestive heart failure, liver cirrhosis and the syndrome of inappropriate antidiuretic hormone secretion. Two nonpeptide vasopressin-receptor antagonists, conivaptan and tolvaptan, have recently been approved by American and European drug authorities for clinical use. This article aims to provide a succinct and clinical update on nonpeptide vasopressin-receptor antagonists, including their mechanism of action, performance in randomized clinical trials and current clinical status.

Validation of model for end-stage liver disease score to serum sodium ratio index as a prognostic predictor in patients with cirrhosis

AIM: To compare the accuracy of model for end-stage liver disease (MELD) to serum sodium (SNa) ratio (MESO) with MELD score and modified Child-Turcotte-Pugh (CTP) score for predicting the short-term survival of cirrhotic patients.

METHODS: The data for 256 patients with cirrhosis were analyzed using a cohort method. The patients were graded based on MELD score into two groups (MELD ≤ 17 and MELD > 17). The area under the receiver operating characteristic curve (AUC) was used to compare the predictive accuracy of MESO index, MELD score and modified CTP score.

RESULTS: Overall, MESO index and MELD score were significantly better than CTP score in predicting the risk of mortality at 1 mo (0.866 and 0.819 vs 0.722, both P < 0.01) and 3 mo (0.875 and 0.820 vs 0.721, both P < 0.01). In the low-MELD group, the AUC of MESO index and CTP was significantly higher than that of MELD score at 1 mo and 3 mo (0.758, 0.759; 0.754, 0.732 vs 0.608, 0.611, all P < 0.01). However, in the high-MELD group, the AUC of MESO index and MELD score was higher than that of CTP score at 1 mo and 3 mo though there were no significant differences (0.762, 0.779; 0.737, 0.773 vs 0.710, 0.752, all P > 0.05).

CONCLUSION: MESO index is superior to MELD score and modified CTP score in the prediction of the short-term survival of patients with cirrhosis.

Inaccuracies of creatinine and creatinine-based equations in candidates for liver transplantation with low creatinine: impact on the model for end-stage liver disease score

Renal function has a significant impact on early mortality in patients with cirrhosis. However, creatinine and creatinine-based equations are inaccurate markers of renal function in cirrhosis. The aim of this study was to reassess correlations between creatinine-based equations and measured glomerular filtration rate (GFR) and to investigate the impact of inaccuracies on the Model for End-Stage Liver Disease (MELD) score. GFR was measured using iohexol clearance and calculated with creatinine-based equations in 157 patients with cirrhosis during pretransplant evaluation. We compared the accuracy of creatinine to that of true GFR in a prognostic score also including bilirubin and the international normalized ratio. In patients with creatinine below 1 mg/dL, true GFR ranged from 34-163 mL/minute/1.73 m(2). Cockcroft and Modification of Diet in Renal Disease (MDRD) significantly overestimated true GFR. On multivariate analysis, younger age and ascites were significantly correlated with the overestimation of true GFR by 20% or more. Body mass index was an independent risk factor of overestimation of GFR with Cockcroft but not with MDRD. The accuracy of a prognostic score combining bilirubin, international normalized ratio, and true GFR was superior to that of MELD, whether creatinine was rounded to 1 mg/dL when lower than 1 mg/dL or not (c-statistic of 0.8 versus 0.75 and 0.73, respectively). Creatinine-based formulas overestimate true GFR, especially in patients younger than 50 years or with ascites. In patients with serum creatinine below 1 mg/dL, the spectrum of true GFR is large. True GFR seems to have a better prognostic value than creatinine and creatinine-based equations. Specific equations are needed in patients with cirrhosis to improve prognostic scores.

Deleterious effects of beta-blockers on survival in patients with cirrhosis and refractory ascites

Beta-blockers may have a negative impact on survival in patients with cirrhosis and refractory ascites. The aim of this study was to evaluate the effect of the administration of beta-blockers on long-term survival in patients with cirrhosis and refractory ascites. We performed a single-center, observational, case-only, prospective study of patients with cirrhosis and refractory ascites who did or did not receive beta-blockers for the prevention of gastrointestinal bleeding; 151 patients were included. The mean Model for End-Stage Liver Disease score was 18.8 +/- 4.1. All patients regularly underwent large-volume paracentesis and intravenous albumin administration. Seventy-seven patients (51%) were treated with propranolol (113 +/- 46 mg/day). The median follow-up for the whole group was 8 months. The median survival time was 10 months [95% confidence interval (CI) = 8-12 months]. The probability of survival at 1 year was 41% (95% CI = 33%-49%). The clinical characteristics and laboratory values at enrolment were not significantly different between patients who were receiving propranolol and those who were not. The median survival time was 20.0 months (95% CI = 4.8-35.2 months) in patients not treated with propranolol and 5.0 months (95% CI = 3.5-6.5 months) in those treated with propranolol (P = 0.0001). The 1-year probability of survival was significantly lower in patients who received propranolol [19% (95% CI = 9%-29%)] versus those who did not [64% (95% CI = 52%-76%), P < 0.0001]. The independent variables of mortality were Child-Pugh class C, hyponatremia and renal failure as causes of refractory ascites, and beta-blocker therapy.

CONCLUSION

The use of beta-blockers is associated with poor survival in patients with refractory ascites. These results suggest that beta-blockers should be contraindicated in these patients.

The survival benefit of liver transplantation in hepatocellular carcinoma patients

BACKGROUND

There are no studies evaluating the survival benefit of liver transplantation over alternative therapies for patients with hepatocellular carcinoma.

METHODS

The short- to mid-term survival benefit (study group=135 aggressively treated patients with hepatocellular carcinoma, 52% beyond Milan criteria at pathology) was calculated by comparing the mortality rates of liver transplantation vs alternative therapies patients. A Markov prediction model was then created to estimate the long-term survival benefit of liver transplantation (gain in life expectancy) over alternative therapies. The long-term survival rates in the liver transplantation group were calculated using the Metroticket website calculator (http://89.96.76.14/metroticket/calculator/).

RESULTS

The short- to mid-term analysis indicated that liver transplantation afforded no significant survival benefit in the group of patients with hepatoma as a whole (hazard ratio=1.229, 95% confidence interval 0.544-2.773, p=.6200). The benefit was concentrated in patients with a poor initial response to alternative therapies (hazard ratio=3.137, 95% confidence interval 1.428-6.891, p=.0044). In the long-term analysis, the gain in life expectancy of liver transplantation vs alternative therapies was 6.115 years (base-case analysis) and the main determinants of gain in life expectancy were the 5-year survival prospects after alternative therapies and the patient's age.

CONCLUSIONS

The survival benefit of liver transplantation for patients with hepatocellular carcinoma is strongly related to the patient's age and the effectiveness of available alternative therapies.

Sodium, potassium and glucose management in organ transplantation

PURPOSE OF REVIEW

To present current knowledge about the metabolic management of patients undergoing solid organ transplantation, and potential organ donors.

RECENT FINDINGS

Appropriate management of electrolytes and glucose improves outcome after transplantation, although conflicting evidence exists. Patients with cirrhosis-induced hyponatremia can be successfully transplanted but are at increased risk of postoperative complications. A new class of drugs, the vaptans, that antagonizes arginine vasopressin may be an effective treatment for hyponatremia in transplant candidates. Recent literature has documented the implications, predictors and potential therapies for perioperative hyperkalemia in the transplant population. The debate over appropriate targets for serum glucose in perioperative and critically ill patients has been lively. The documented risk of hypoglycemia associated with 'intensive insulin therapy' has led to the adoption of more conservative glycemic targets. Studies of glycemic control in transplant recipients are limited.

SUMMARY

In patients undergoing solid organ transplants, sodium management should aim to minimize an acute change in sodium concentration. Vaptans may be of future use in optimizing patients with cirrhosis prior to transplantation. Pending further studies, a perioperative 'middle ground' target glucose of between 140 and 180 mg/dl seems reasonable at this time.

Six score systems to evaluate candidates with advanced cirrhosis for orthotopic liver transplant: Which is the winner?

Many prognostic systems have been devised to predict the outcome of liver transplantation (LT) candidates. Today, the Model for End-Stage Liver Disease (MELD) is widely used for organ allocation, but it has shown some limitations. The aim of this study was to investigate the performance of MELD compared to 5 different score models. We evaluated the prognostic ability of MELD, modified Child-Turcotte-Pugh, MELD-sodium, United Kingdom MELD, updated MELD, and integrated MELD in 487 candidates with cirrhosis for LT at the Bologna Transplant Centre, Bologna, Italy, between 2003 and 2008. Calibration analysis by Hosmer-Lemeshow test, calibration curves, and concordance c-statistics (area under the receiver operating characteristic curve [AUC]) were calculated at 3, 6, and 12 months. Actual cumulative survival curves, taking into account the event of interest in the presence of competing risk, were obtained using the best cutoffs identified by AUC. For each score, the Hosmer-Lemeshow test revealed a good calibration. Integrated MELD showed calibration curves closer to the line of perfect predicting ability, followed by MELD-sodium at 3 months and modified Child-Turcotte-Pugh at 6 months. MELD-sodium AUCs at 3 and 6 months (0.798 and 0.765, respectively) and integrated MELD AUC at 6 months (0.792) were better than standard MELD (P < 0.05). Actual survival curves showed that these 2 scores were able to identify the patients with the highest drop-out risk. In conclusion, MELD-sodium and integrated MELD were the best prognostic models to predict drop-out rates among patients awaiting LT.

A new prognostic model for hepatocellular carcinoma based on total tumor volume: the Taipei Integrated Scoring System

BACKGROUND & AIMS

The currently used staging systems for hepatocellular carcinoma (HCC) are not satisfactory. The optimal prognostic model for HCC is still under intense debate. This study aimed to propose a new staging system for HCC based on total tumor volume (TTV) and to compare it with the currently used systems.

METHODS

A total of 2030 HCC patients undergoing different treatment strategies were retrospectively analyzed. TTV was defined as the sum of the volume of each tumor [(4/3)x3.14x(radius of tumor in cm)(3)]. The discriminatory ability of the TTV-based staging system and the four current systems, including the Barcelona Clinic Liver Cancer, Cancer of the Liver Italian Program (CLIP), Japan Integrated Staging system, and Tokyo system, was examined by comparing the Akaike information criterion (AIC) using the Cox proportional hazards model.

RESULTS

A higher TTV correlated well with the decreased survival in HCC patients (p<0.001). Among the 12 TTV-based staging systems, the TTV-Child-Turcotte-Pugh (CTP)-alpha-fetoprotein (AFP) combination provided the lowest AIC value. The TTV-CTP-AFP model consistently showed a better prognostic ability in comparison to the current four staging systems. In 936 HCC patients receiving curative treatment, the TTV-CTP-AFP model provided the second best predictive accuracy following the CLIP score. Alternatively, in 1094 patients undergoing non-curative treatment, the TTV-CTP-AFP model exhibited the smallest AIC value.

CONCLUSIONS

TTV may be a feasible tumoral prognostic predictor for HCC. In this single-hospital study that included patients with early to advanced cancer stages, the TTV-CTP-AFP model provides the best prognostic ability among 12 TTV-based and currently used staging systems.

New aspects in the pathogenesis, prevention, and treatment of hyponatremic encephalopathy in children

Hyponatremia is the most common electrolyte abnormality encountered in children. In the past decade, new advances have been made in understanding the pathogenesis of hyponatremic encephalopathy and in its prevention and treatment. Recent data have determined that hyponatremia is a more serious condition than previously believed. It is a major comorbidity factor for a variety of illnesses, and subtle neurological findings are common. It has now become apparent that the majority of hospital-acquired hyponatremia in children is iatrogenic and due in large part to the administration of hypotonic fluids to patients with elevated arginine vasopressin levels. Recent prospective studies have demonstrated that administration of 0.9% sodium chloride in maintenance fluids can prevent the development of hyponatremia. Risk factors, such as hypoxia and central nervous system (CNS) involvement, have been identified for the development of hyponatremic encephalopathy, which can lead to neurologic injury at mildly hyponatremic values. It has also become apparent that both children and adult patients are dying from symptomatic hyponatremia due to inadequate therapy. We have proposed the use of intermittent intravenous bolus therapy with 3% sodium chloride, 2 cc/kg with a maximum of 100 cc, to rapidly reverse CNS symptoms and at the same time avoid the possibility of overcorrection of hyponatremia. In this review, we discuss how to recognize patients at risk for inadvertent overcorrection of hyponatremia and what measures should taken to prevent this, including the judicious use of 1-desamino-8d-arginine vasopressin (dDAVP).

Managing hyponatremia in cirrhosis

The development of hyponatremia represents an ominous event in the progression of cirrhosis to end-stage liver disease. It usually develops in those with refractory ascites and is a manifestation of the non-osmotic release of arginine vasopressin (AVP). In the hospitalized cirrhotic patient, hyponatremia is associated with increased disease severity and mortality. In this article, we review the pathophysiology of hyponatremia, its clinical implications, evaluation, and treatment.

The prognostic value of N-terminal pro-B-type natriuretic peptide for death and cardiovascular events in healthy normal and stage A/B heart failure subjects

OBJECTIVES

Our objective was to determine the prognostic value of plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) for death and cardiovascular events among subjects without risk factors for heart failure (HF), which we term healthy normal.

BACKGROUND

Previous studies report that plasma NT-proBNP has prognostic value for cardiovascular events in the general population even in the absence of HF. It is unclear if NT-proBNP retains predictive value in healthy normal subjects.

METHODS

We identified a community-based cohort of 2,042 subjects in Olmsted County, Minnesota. Subjects with symptomatic (stage C/D) HF were excluded. The remaining 1,991 subjects underwent echocardiography and NT-proBNP measurement. We further defined healthy normal (n = 703) and stage A/B HF (n = 1,288) subgroups. Healthy normal was defined as the absence of traditional clinical cardiovascular risk factors and echocardiographic structural cardiac abnormalities. Subjects were followed for death, HF, cerebrovascular accident, and myocardial infarction with median follow-up of 9.1, 8.7, 8.8, and 8.9 years, respectively.

RESULTS

NT-proBNP was not predictive of death or cardiovascular events in the healthy normal subgroup. Similar to previous reports, in stage A/B HF, plasma NT-proBNP values greater than age-/sex-specific 80th percentiles were associated with increased risk of death, HF, cerebrovascular accident, and myocardial infarction (p < 0.001 for all) even after adjustment for clinical risk factors and structural cardiac abnormalities.

CONCLUSIONS

These findings do not support the use of NT-proBNP as a cardiovascular biomarker in healthy normal subjects and have important implications for NT-proBNP-based strategies for early detection and primary prevention of cardiovascular disease.

Serum ferritin concentration predicts mortality in patients awaiting liver transplantation

Additional markers are required to identify patients on the orthotopic liver transplant (OLT) waiting list at increased risk of death and adverse clinical events. Serum ferritin concentration is a marker of varied pathophysiological events and is elevated with increased liver iron concentration, hepatic necroinflammation, and systemic illness, all of which may cause a deterioration in liver function and clinical status. The aim of this study was to determine whether serum ferritin concentration is an independent prognostic factor in subjects awaiting OLT. This is a dual-center retrospective study. The study cohort consisted of 191 consecutive adults with cirrhosis accepted by the Queensland (Australia) Liver Transplant Service between January 2000 and June 2006 and a validation cohort of 131 patients from University of California Los Angeles (UCLA) Transplant Center. In the study cohort, baseline serum ferritin greater than 200 microg/L was an independent factor predicting increased 180-day and 1-year waiting list mortality. This effect was independent of model for end-stage liver disease (MELD), hepatocellular carcinoma, age, and sex. Subjects with higher serum ferritin had increased frequency of liver-related clinical events. The relationship between serum ferritin and waiting list mortality was confirmed in the UCLA cohort; all deceased patients had serum ferritin greater than 400 microg/L. Serum ferritin greater than 500 microg/L and MELD were independent risk factors for death.

CONCLUSION

Serum ferritin concentration is an independent predictor of mortality-related and liver-related clinical events. Baseline serum ferritin identifies a group of "higher-risk" patients awaiting OLT and should be investigated as an adjunct to MELD in organ allocation.

Organ allocation for chronic liver disease: model for end-stage liver disease and beyond

PURPOSE OF REVIEW

Implementation of the model for end-stage liver disease (MELD) score has led to a reduction in waiting list registration and waitlist mortality. Prognostic models have been proposed to either refine or improve the current MELD-based liver allocation.

RECENT FINDINGS

The model for end-stage liver disease - sodium (MELDNa) incorporates serum sodium and has been shown to improve the predictive accuracy of the MELD score. However, laboratory variation and manipulation of serum sodium is a concern. Organ allocation in the United Kingdom is now based on a model that includes serum sodium. An updated MELD score is associated with a lower relative weight for serum creatinine coefficient and a higher relative weight for bilirubin coefficient, although the contribution of reweighting coefficients as compared with addition of variables is unclear. The D-MELD, the arithmetic product of donor age and preoperative MELD, proposes donor-recipient matching; however, inappropriate transplantation of high-risk donors is a concern. Finally, the net benefit model ranks patients according to the net survival benefit that they would derive from the transplant. However, complex statistical models are required and unmeasured characteristics may unduly affect the model.

SUMMARY

Despite their limitations, efforts to improve the current MELD-based organ allocation are encouraging.

Impact of preoperative serum sodium concentration in living donor liver transplantation

BACKGROUND AND AIMS

The importance of hyponatremia in deceased donor liver transplantation (DDLT) has been recently discussed frequently. However, its impact on the outcomes in living donor liver transplantation (LDLT) has not yet been elucidated. The current study was designed to demonstrate the impact of pre-transplant sodium concentration on postoperative clinical outcomes.

METHODS

One hundred and thirty-four patients who underwent LDLT for end-stage liver diseases were examined to evaluate the significance of pre-transplant hyponatremia (Na < or = 130 mEq/L) on the short-term clinical outcomes and the efficacy of the Model for End-Stage Liver Disease and serum sodium (MELD-Na) score using the sodium concentration and original MELD score.

RESULTS

The preoperative sodium and MELD score for all patients were 133.9 mEq/L (range: 109-142) and 16.2 (range: 6-38), respectively. According to a multivariate analysis, not only the MELD score (P = 0.030) but also the sodium concentration (P = 0.005) were found to be significant predictive factors for short-term graft survival. Preoperative hyponatremia was a significant risk factor for the occurrence of sepsis (P < 0.001), renal dysfunction (P < 0.001) and encephalopathy (P = 0.026). The MELD-Na score was 19.6 (range: 6-51) and the area under the receiver-operator curve of that (c-statistics: 0.867) was higher than MELD score and sodium concentration (c-statistics: 0.820 and 0.842, respectively).

CONCLUSION

Preoperative hyponatremia was a significant risk for postoperative complications and short-term graft loss. The addition of sodium concentration to MELD score might therefore be an effective predictor for post-transplant short-term mortality in LDLT.

Disparities in organ allocation and access to liver transplantation in the USA

Liver transplantation has become the standard of care for the treatment of chronic liver disease. In 1986, the United Network for Organ Sharing (UNOS) was formed to ensure the just and equitable allocation of donor livers. At the time, UNOS decided to use the Childs-Turcotte-Pugh scoring system to determine the degree of liver disease in potential transplant patients. Unfortunately, it was shown that the Childs-Turcotte-Pugh system was easily manipulated and did not provide equal access to donor organs. Owing to this fact, the Model of End Stage Liver Disease (MELD) score was instituted by UNOS in February 2002. While the institution of MELD has shown an improvement in organ allocation and outcomes, disparities still exist. This article discusses UNOS and the MELD allocation system as well as the racial, geographic and gender disparities that occur despite the institution of the MELD system.

Serum sodium, renal function, and survival of patients with end-stage liver disease

BACKGROUND & AIMS

Serum creatinine, a component of the model for end-stage liver disease (MELD), is an important prognostic indicator in patients with end-stage liver disease (ESLD). In addition, serum sodium has recently been recognized as an important predictor of mortality in patients with ESLD. We investigate the role of serum creatinine and sodium, and glomerular filtration rate (GFR) as determinants of survival in patients with ESLD.

METHODS

A prospective database was utilized to identify all adults listed for primary liver transplantation (LTx) at the Mayo Clinic, Rochester, between 1990 and 1999. GFR was measured by iothalamate clearance.

RESULTS

Among 837 patients listed for LTx, 660 had complete data including measured GFR. There was a significant association between GFR and survival after adjustment for MELD, with a linear rise in the risk of death as GFR decreased between 60 and 20ml/min/1.73m(2). Multivariable models showed that GFR is superior to creatinine in predicting mortality - a model consisting of total bilirubin (hazard ratio (HR)=2.17, p<0.01), INR (HR=3.26, p<0.01) and GFR (HR=0.42, p<0.01) was superior to MELD (chi-square 65.6 vs. 59.4, c-statistic 0.792 vs. 0.780). Serum sodium did not contribute to survival prediction when accurately measured GFR data were available.

CONCLUSIONS

Serum concentrations of creatinine and sodium in patients with end-stage liver disease reflect a reduction in renal function, the underlying event that decreases survival.

Pretransplant predictors of recovery of renal function after liver transplantation

The Model for End-Stage Liver Disease system has given priority on the liver transplant waiting list to candidates with renal failure. This study determined the predictors of spontaneous recovery of renal function after transplantation in 1041 liver transplant recipients on renal replacement therapy (RRT) at the time of transplant (from February 2002 to January 2007). Data from these patients were obtained from the US Organ Procurement and Transplantation Network and US Renal Data System databases. Univariate and multivariate survival models were constructed along with multivariate logistic regression models to find independent predictors of spontaneous renal recovery. Seven hundred seven recipients (67.9%) had spontaneous recovery of renal function after liver transplantation. Those recovering spontaneously had a significantly shorter course of RRT in the pretransplant time period (15.6 versus 36.6 days, P < 0.001). Recovery of renal function was observed in 70.8% and 11.5% of recipients on RRT for less than 30 days and more than 90 days, respectively. Other statistically significant pretransplant variables independently associated with recovery of renal function included recipient age, recipient pretransplant diabetes, and donor age. In conclusion, the duration of pretransplant RRT is highly predictive of spontaneous renal recovery post-transplant. Liver transplant candidates requiring less than 30 days of pretransplant RRT are likely to spontaneously recover renal function after liver transplantation, whereas those on RRT for more than 90 days are not.

Profound hyponatremia in cirrhosis: a case report

Introduction

Cirrhosis of the liver commonly leads to a state of chronic hypervolemic hyponatremia. Profound exacerbation of the hyponatremic state may occur in patients with decompensated cirrhosis in conjunction with acute stressors such as infection or binge alcohol ingestion.

Case presentation

A 47 year old man with a history of alcoholic cirrhosis presented to the hospital with symptomatic profound hyponatremia (serum sodium concentration of 105 meq/L) due to a recent infection and binge drinking. The patient was treated with antibiotics, diuretics and hypertonic saline and was placed on a fluid restricted diet. The serum sodium level corrected slowly over four days with symptomatic improvement occurring after two days. A brief discussion of the symptoms and treatment of acute and chronic hyponatremia in the setting of cirrhosis is included.

Conclusion

In patients with cirrhosis, it is important to recognize the symptoms of hyponatremia, identify and treat any exacerbating conditions early in their course, and correct the serum sodium concentration slowly with frequent monitoring.