The growing evidence that renal function should be improved in patients with cirrhosis and hepatorenal syndrome before liver transplantation

Hepatorenal syndrome in the era of acute kidney injury

Acute kidney injury (AKI) is a frequent complication of patients with advanced cirrhosis that it is associated with increased hospital admissions and decreased survival. The definition of AKI in cirrhosis has been recently modified and the new diagnostic criteria are based on small changes in serum creatinine with respect to previous values, occurring within a short period of time. The use of this new definition may lead to an earlier identification of renal impairment and better prognostic stratification. Hepatorenal syndrome (HRS) is a unique form of AKI developing in patients with end-stage liver disease. Systemic circulatory dysfunction and marked kidney vasoconstriction play a key role in the development of HRS. The modification of the definition of AKI has also led to a change in the diagnostic criteria of HRS. The new diagnostic criteria are based on AKI stages and there is no need to reach a specific serum creatinine threshold. According to these new criteria, treatment with vasoconstrictors and albumin for the management of HRS will be started at lower serum creatinine values, with expected higher response rates. Finally, there are consistent data showing that some urine biomarkers, particularly NGAL (neutrophil gelatinase-associated lipocalin), may be useful in daily clinical practice for the differential diagnosis of the cause of AKI in cirrhosis.

Type-1 hepatorenal syndrome associated with infections in cirrhosis: natural history, outcome of kidney function, and survival

Type-1 hepatorenal syndrome (HRS) is a common complication of bacterial infections in cirrhosis, but its natural history remains undefined. To assess the outcome of kidney function and survival of patients with type-1 HRS associated with infections, 70 patients diagnosed during a 6-year period were evaluated prospectively. Main outcomes were no reversibility of type-1 HRS during treatment of the infection and 3-month survival. Forty-seven (67%) of the 70 patients had no reversibility of type-1 HRS during treatment of the infection. [Correction to previous sentence added March 10, 2014, after first online publication: "Twenty-three (33%)" was changed to "Forty-seven (67%)."] The main predictive factor of no reversibility of type-1 HRS was absence of infection resolution (no reversibility: 96% versus 48% in patients without and with resolution of the infection; P < 0.001). Independent predictive factors of no reversibility of type-1 HRS were age, high baseline serum bilirubin, nosocomial infection, and reduction in serum creatinine <0.3 mg/dL at day 3 of antibiotic treatment. No reversibility was also associated with severity of circulatory dysfunction, as indicated by more marked activity of the vasoconstrictor systems. In the whole series, 3-month probability of survival was only 21%. Factors associated with poor prognosis were baseline serum bilirubin, no reversibility of type-1 HRS, lack of resolution of the infection, and development of septic shock after diagnosis of type-1 HRS.

CONCLUSION

Type-1 HRS associated with infections is not reversible in two-thirds of patients with treatment of infection only. No reversibility of type-1 HRS is associated with lack of resolution of the infection, age, high bilirubin, and no early improvement of kidney function and implies a poor prognosis. These results may help advance the management of patients with type-1 HRS associated with infections.

Impact of liver transplantation on the survival of patients treated for hepatorenal syndrome type 1

The development of hepatorenal syndrome type 1 (HRS1) is associated with a poor prognosis. Liver transplantation improves this prognosis, but the degree of the improvement is unclear. Most patients receive vasoconstrictors such as terlipressin before transplantation, and this may affect the posttransplant outcomes. We examined a cohort of patients with access to liver transplantation from our previously published study of terlipressin plus albumin versus albumin alone in the treatment of HRS1. The purpose of this analysis was the quantification of the survival benefits of liver transplantation for patients with HRS1. Ninety-nine patients were randomized to terlipressin or placebo. Thirty-five patients (35%) received a liver transplant. Among those receiving terlipressin plus albumin, the 180-day survival rates were 100% for transplant patients and 34% for nontransplant patients; among those receiving only albumin, the rates were 94% for transplant patients and 17% for nontransplant patients. The survival rate was significantly better for those achieving a reversal of hepatorenal syndrome (HRS) versus those not achieving a reversal (47% versus 4%, P < 0.001), but it was significantly lower for the responders versus those undergoing liver transplantation (97%). We conclude that the use of terlipressin plus albumin has no significant impact on posttransplant survival. Liver transplantation offers a clear survival benefit to HRS1 patients regardless of the therapy that they receive or the success or failure of HRS reversal. The most likely benefit of terlipressin in patients undergoing liver transplantation for HRS1 is improved pretransplant renal function, and this should make the posttransplant management of this difficult group of patients easier. For patients not undergoing transplantation, HRS reversal with terlipressin and/or albumin improves survival.

Haemodynamic effects of plasma-expansion with hyperoncotic albumin in cirrhotic patients with renal failure: a prospective interventional study

Background

Patients with advanced cirrhosis of the liver typically display circulatory disturbance. Haemodynamic management may be critical for avoiding and treating functional renal failure in such patients. This study investigated the effects of plasma expansion with hyperoncotic albumin solution and the role of static haemodynamic parameters in predicting volume responsiveness in patients with advanced cirrhosis.

Methods

Patients with advanced cirrhosis (Child B and C) of the liver receiving albumin substitution because of renal compromise were studied using trans-pulmonary thermodilution. Paired measurements before and after two infusions of 200 ml of 20% albumin per patient were recorded and standard haemodynamic parameters such as central venous pressure (CVP), mean arterial pressure (MAP), systemic vascular resistance index (SVRI), cardiac index (CI) and derived variables were assessed, including global end-diastolic blood volume index (GEDVI), a parameter that reflects central blood volume

Results

100 measurements in 50 patients (33 m/17 w; age 56 years (± 8); Child-Pugh-score 12 (± 2), serum creatinine 256 μmol (± 150) were analyzed. Baseline values suggested decreased central blood volumes GEDVI = 675 ml/m² (± 138) despite CVP within the normal range (11 mmHg (± 5). After infusion, GEDVI, CI and CVP increased (682 ml/m² (± 128) vs. 744 ml/m² (± 171), p < 0.001; 4.3 L/min/m² (± 1.1) vs. 4.7 L/min/m² (± 1.1), p < 0.001; 12 mmHg (± 6) vs. 14 mmHg (± 6), p < 0.001 respectively) and systemic vascular resistance decreased (1760 dyn s/cm⁵/m² (± 1144) vs. 1490 dyn s/cm⁵/m² (± 837); p < 0.001). Changes in GEDVI, but not CVP, correlated with changes in CI (r² = 0.51; p < 0.001). To assess the value of static haemodynamic parameters at baseline in predicting an increase in CI of 10%, receiver-operating-characteristic curves were constructed. The areas under the curve were 0.766 (p < 0.001) for SVRI, 0.723 (p < 0.001) for CI, 0.652 (p = 0.010) for CVP and 0.616 (p = 0.050) for GEDVI.

Conclusion

In a substantial proportion of patients with advanced cirrhosis, plasma expansion results in an increase in central blood volume. GEDVI but not CVP behaves as an indicator of cardiac preload, whereas high baseline SVRI is predictive of fluid responsiveness.

[Dilutional hyponatremia, hepatorenal syndrome and liver transplantation]

Cirrhosis is a chronic, progressive disease characterized by complications associated with portal hypertension and liver failure. Renal function disorders are a common complication in patients with cirrhosis and are associated with high morbidity and mortality and poor prognosis. Renal function alterations in these patients include sodium and water retention and renal vasoconstriction. Sodium retention causes the formation of ascites and edema, solute-free water leads to dilutional hyponatremia, and renal vasoconstriction gives rise to the development of hepatorenal syndrome (HRS). Due to their poor prognosis, the presence of ascites, dilutional hyponatremia and HRS are indications for liver transplantation (LT). Recent studies have allowed new prognostic factors in these patients to be identified, novel treatments for dilutional hyponatremia and HRS to be applied, and the association of these complications with disease course and outcome before and after LT to be described. The present review discusses new concepts of the physiopathology, evaluation and treatment of cirrhotic patients with dilutional hyponatremia and HRS and the relationship of these entities with LT.

Systematic review: renal and other clinically relevant outcomes in hepatorenal syndrome trials

BACKGROUND

Although reversal of pretransplant renal dysfunction in hepatorenal syndrome reduces post-transplant complications, the overall impact on morbidity and mortality requires clarification.

AIM

To review trials of pharmacologic interventions in hepatorenal syndrome, with specific assessment of trial quality and study endpoints, including patient survival and renal outcome measures.

METHODS

Literature search and selection was carried out by a single reviewer. Data extraction and quality analysis were carried out by two independent reviewers.

RESULTS

Of 848 identified articles, 36 were eligible for inclusion. Twenty-one were full-text. Only 19% were randomized-controlled trials. About 50% of studies included only Type 1 hepatorenal syndrome patients. Serum creatinine, urine output and urine sodium were the most common renal outcome measures. Only 42% defined a primary renal endpoint. About 88% of articles reported mortality rates.

CONCLUSIONS

Existing literature of pharmacologic agents for use in hepatorenal syndrome is limited by poor study design, including non-randomization, heterogeneous study populations, lack of power, and limited use of clinically relevant outcomes. There is insufficient information in most trials to judge the impact of pharmacologic therapy on mortality or rates of transplantation. The validity of renal outcome measures as surrogate markers of more clinically relevant endpoints has not been established.

Diagnosis and treatment of acute renal failure in patients with cirrhosis

In patients with cirrhosis, acute renal failure is due to prerenal failure (a result of decreased renal perfusion) and tubular necrosis. There are 3 main causes of prerenal failure: 'true hypovolemia' (which complicates hemorrhage, gastrointestinal or renal fluid losses), sepsis, and type 1 hepatorenal syndrome (HRS). Prerenal failure may also be due to the administration of non-steroidal antiinflammatory drugs, or intravascular radiocontrast agents. Prerenal failure is reversible after restoration of renal blood flow. Treatments target the cause of hypoperfusion, and fluid replacement is used to treat 'non-HRS' prerenal failure. In patients with type 1 HRS with very low short-term survival rate, liver transplantation is the ideal treatment. Systemic vasoconstrictor therapy with terlipressin (combined with intravenous human albumin), noradrenaline (combined with albumin and furosemide) or midodrine (combined with octreotide and albumin) may improve renal function in patients with type 1 HRS waiting for liver transplantation. MARS (for Molecular Adsorbent Recirculating System) and the transjugular intrahepatic portosystemic shunt may also improve renal function in these patients. In patients with cirrhosis, acute tubular necrosis is mainly due to an ischemic insult to the renal tubules. Studies are needed on the natural course and treatment (e.g., renal-replacement therapy) of acute tubular necrosis in patients with cirrhosis.

The use of vasoconstrictors in patients with cirrhosis: type 1 HRS and beyond

In patients with cirrhosis and type 1 hepatorenal syndrome (HRS), systemic vasodilation, which is mainly attributable to splanchnic vasodilation, plays a critical role in the activation of endogenous vasoconstrictor systems, resulting in renal vasoconstriction and functional renal failure. It has been suggested that the use of splanchnic (and systemic) vasoconstrictors such as terlipressin (a vasopressin analog) or alpha-1-adrenoceptor agonists (midodrine or noradrenaline) may improve renal function in patients with type 1 HRS. Six studies (with only one randomized study in a small series of patients) have shown that terlipressin improves renal function in these patients. However, there is evidence that terlipressin alone may be less effective than terlipressin combined with intravenous albumin in improving renal function. Future randomized studies should confirm this difference and evaluate the impact of terlipressin therapy (with or without intravenous albumin) on survival. Interestingly, in nonrandomized studies, the use of alpha-1 agonists combined with other therapies (octreotide and albumin for midodrine; furosemide and albumin for noradrenaline) has been shown to improve renal function in patients with type 1 HRS. The efficacy and safety of combined therapies including alpha-1 agonists should be confirmed in randomized studies. Finally, preliminary evidence suggests that vasoconstrictor administration may be a novel therapeutic approach targeting vasodilation involved in the mechanism of: (1) renal failure in type 2 HRS; (2) paracentesis-induced circulatory dysfunction; and (3) arterial hypotension induced by byproducts of gram-negative bacteria. Further studies are needed in all these fields.

Preoperative optimization of patients with liver disease

PURPOSE OF REVIEW

Recent papers relevant to the preoperative evaluation and optimization of patients with severe liver disease will be discussed. The emphasis will be placed on cardiovascular, pulmonary, and renal complications. Other aspects such as preoperative management of hepatitis B and C, other infectious issues, and liver cancer will not be discussed because this rarely involves the anesthesiologist.

RECENT FINDINGS

Dobutamine stress echocardiography has been the cornerstone of cardiac evaluation of liver transplant candidates. Combining liver transplantation with cardiac procedures has been shown to be feasible. While mild hepatopulmonary syndrome is well-tolerated, severe hepatopulmonary syndrome carries a fairly high mortality rate. New treatment modalities of severe portopulmonary hypertension have been introduced, and may have advantages over epoprostenol administration. Hepatic hydrothorax requires similar therapy to ascites [repeated thoracentesis or paracentesis, and transjugular intrahepatic portosystemic shunt (TIPS)], but refractory hydrothorax may require other interventions. Hepatorenal syndrome may improve by increasing renal blood flow through the use of vasoconstrictors (vasopressin, norepinephrine) in combination with albumin administration. Interventional radiologists can now change the flow through an established TIPS. Hepatic encephalopathy may result in some irreversible changes in the brain. It remains difficult to predict whether a patient with acute fulminant failure will recover spontaneously. Support devices that include hepatocytes show early promising results. The coagulation changes in living donors are incompletely understood. Finally, autonomic neuropathy as a complication of severe liver disease results in more hemodynamic instability.

SUMMARY

Recent advances in preoperative evaluation and optimization are presented and discussed.

Review article: pharmacological treatment of hepatorenal syndrome

Hepatorenal syndrome (HRS) is a common complication of advanced cirrhosis characterized not only by renal failure but also by marked alterations in systemic haemodynamics and activity of endogenous vasoactive systems. Renal failure is due to a severe vasoconstriction of the renal circulation. The pathogenesis of HRS is not completely understood but it is probably the result of extreme underfilling of the arterial circulation secondary to arterial vasodilation located in the splanchnic circulation. As well as the renal circulation, all other extrasplanchnic vascular beds appear to be vasoconstricted. The diagnosis of HRS is currently based on the exclusion of nonfunctional causes of renal failure; prognosis of patients with HRS is very poor. Liver transplantation is the best option in selected patients, but it is not always applicable as survival expectancy is short. Vasoconstrictor drugs with preferential effect on the splanchnic circulation (vasopressin analogues with a predominant V1 receptor effect, such as terlipressin--Glypressin) are very effective in improving renal function, with reversal of HRS being achieved in approximately two-thirds of patients. There is no agreement as to the terlipressin treatment regimen that is associated with a greater efficacy and lower incidence of side-effects. It appears that the administration of albumin together with terlipressin improves the therapeutic response rate. The impact of treatment on the natural course of HRS remains to be assessed in prospective investigations, but it seems that the reversal of HRS is associated with improved survival. Finally, treatment of patients with HRS with terlipressin before transplantation seems to improve post-transplantation outcome.