Acute kidney injury in children with chronic liver disease

Intraoperative kidney replacement therapy in acute liver failure

Paediatric acute liver failure (PALF) is often characterised by its rapidity of onset and potential for significant morbidity and even mortality. Patients often develop multiorgan dysfunction/failure, including severe acute kidney injury (AKI). Whilst the management of PALF focuses on complications of hepatic dysfunction, the associated kidney impairment can significantly affect patient outcomes. Severe AKI requiring continuous kidney replacement therapy (CKRT) is a common complication of both PALF and liver transplantation. In both scenarios, the need for CKRT is a poor prognostic indicator. In adults, AKI has been shown to complicate ALF in 25-50% of cases. In PALF, the incidence of AKI is often higher compared to other critically ill paediatric ICU populations, with reports of up to 40% in some observational studies. Furthermore, those presenting with AKI regularly have a more severe grade of PALF at presentation. Observational studies in the paediatric population corroborate this, though data are not as robust-mainly reflecting single-centre cohorts. Perioperative benefits of CKRT include helping to clear water-soluble toxins such as ammonia, balancing electrolytes, preventing fluid overload, and managing raised intracranial pressure. As liver transplantation often takes 6-10 h, it is proposed that these benefits could be extended to the intraoperative period, avoiding any hiatus. Intraoperative CKRT (IoCKRT) has been shown to be practicable, safe and may help sicker recipients tolerate the operation with outcomes analogous with less ill patients not requiring IoCKRT. Here, we provide a comprehensive guide describing the rationale, practicalities, and current evidence base surrounding IoCKRT during transplantation in the paediatric population.

Identifying drivers of cost in pediatric liver transplantation

Understanding the economics of pediatric liver transplantation (LT) is central to high-value care initiatives. We examined cost and resource utilization in pediatric LT nationally to identify drivers of cost and hospital factors associated with greater total cost of care. We reviewed 3295 children (<21 y) receiving an LT from 2010 to 2020 in the Pediatric Health Information System to study cost, both per LT and service line, and associated mortality, complications, and resource utilization. To facilitate comparisons, patients were stratified into high-cost, intermediate-cost, or low-cost tertiles based on LT cost. The median cost per LT was $150,836 [IQR $104,481-$250,129], with marked variance in cost within and between hospital tertiles. High-cost hospitals (HCHs) cared for more patients with the highest severity of illness and mortality risk levels (67% and 29%, respectively), compared to intermediate-cost (60%, 21%; p <0.001) and low-cost (51%, 16%; p <0.001) hospitals. Patients at HCHs experienced a higher prevalence of mechanical ventilation, total parental nutrition use, renal comorbidities, and surgical complications than other tertiles. Clinical (27.5%), laboratory (15.1%), and pharmacy (11.9%) service lines contributed most to the total cost. Renal comorbidities ($69,563) and total parental nutrition use ($33,192) were large, independent contributors to total cost, irrespective of the cost tertile ( p <0.001). There exists a significant variation in pediatric LT cost, with HCHs caring for more patients with higher illness acuity and resource needs. Studies are needed to examine drivers of cost and associated outcomes more granularly, with the goal of defining value and standardizing care. Such efforts may uniquely benefit the sicker patients requiring the strategic resources located within HCHs to achieve the best outcomes.

Prevalence, Associated Factors, and Outcomes of Severe Acute Kidney Injury in Pediatric Acute Liver Failure: Single-Center Retrospective Study, 2003-2017

OBJECTIVES

Our aim was to determine the prevalence and explanatory factors associated with outcomes in children with acute liver failure (ALF) admitted to the PICU, who also develop severe acute kidney injury (AKI).

DESIGN

Retrospective cohort, 2003 to 2017.

SETTING

Sixteen-bed PICU in a university-affiliated tertiary care hospital.

PATIENTS

Admissions to the PICU with ALF underwent data review of the first week and at least 90-day follow-up. Patients with stages 2-3 AKI using the British Association of pediatric Nephrology definitions, or receiving continuous renal replacement therapy (CRRT) for renal indications, were defined as severe AKI. We excluded ALF cases on CRRT for hepatic-only indications.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Baseline characteristics, proportion with severe AKI, illness severity and interventions, and outcomes (i.e., transplant, survival with native liver, overall survival, duration of PICU stay, and mechanical ventilation). Ninety-four children with ALF admitted to the PICU were included. Over the first week, 29 had severe AKI, and another eight received CRRT for renal/mixed reno-hepatic indications; hence, the total severe AKI cohort was 37 of 94 (39.4%). In a multivariable logistic regression model, peak aspartate aminotransferase (AST) and requirement for inotropes on arrival were associated with severe AKI. Severe AKI was associated with longer PICU stay and duration of ventilation, and lower spontaneous survival with native liver. In another model, severe AKI was associated with greater odds of mortality (odds ratio 7.34 [95% CI, 1.90-28.28], p = 0.004). After 90 days, 3 of 17 survivors of severe AKI had serum creatinine greater than the upper limit of normal for age.

CONCLUSIONS

Many children with ALF in the PICU develop severe AKI. Severe AKI is associated with the timecourse of PICU admission and outcome, including survival with native liver. Future work should look at ALF goal directed renoprotective strategies at the time of presentation.

Acute kidney injury in patients with cirrhosis: Acute Disease Quality Initiative (ADQI) and International Club of Ascites (ICA) joint multidisciplinary consensus meeting

Patients with cirrhosis are prone to developing acute kidney injury (AKI), a complication associated with a markedly increased in-hospital morbidity and mortality, along with a risk of progression to chronic kidney disease. Whereas patients with cirrhosis are at increased risk of developing any phenotype of AKI, hepatorenal syndrome (HRS), a specific form of AKI (HRS-AKI) in patients with advanced cirrhosis and ascites, carries an especially high mortality risk. Early recognition of HRS-AKI is crucial since administration of splanchnic vasoconstrictors may reverse the AKI and serve as a bridge to liver transplantation, the only curative option. In 2023, a joint meeting of the International Club of Ascites (ICA) and the Acute Disease Quality Initiative (ADQI) was convened to develop new diagnostic criteria for HRS-AKI, to provide graded recommendations for the work-up, management and post-discharge follow-up of patients with cirrhosis and AKI, and to highlight priorities for further research.

Systemic Complications Secondary to Chronic Liver Disease

The systemic sequelae of chronic liver disease (CLD) may be due to portal hypertension and shunting, malnutrition, and/or a low grade inflammatory state. This article will focus on the consequences of chronic liver disease affecting extrahepatic organs. Portal hypertension underlies many systemic complications of CLD. Aside from varices and ascites, portal hypertension may cause both hepatopulmonary syndrome and portopulmonary hypertension leading to respiratory compromise. Cardiomyopathy may also occur secondary to end stage liver disease. Hepatorenal syndrome is also well recognised and hepatic encephalopathy is a consequence of the effect of liver dysfunction on the brain. Compromise of the immune system is well described in end-stage liver disease leading to sepsis and its consequences. Bony disease including osteoporosis and hepatic arthropathy may both be seen in children with CLD. CLD may be asymptomatic initially but then complications may present as the disease progresses. Furthermore, systemic effects of end stage liver disease may complicate liver transplant. These complications often present insidiously or at the time of acute decompensation. Thus, it is important that healthcare providers are vigilant when caring for children with CLD. This article outlines the secondary complications of CLD with an overview of the definition and diagnosis, pathophysiology, management and prognosis of each.

Epoprostenol (Prostacyclin Analog) as a Sole Anticoagulant in Continuous Renal Replacement Therapy for Critically Ill Children With Liver Disease: Single-Center Retrospective Study, 2010-2019

OBJECTIVES

Despite deranged coagulation, children with liver disease undergoing continuous renal replacement therapy (CRRT) are prone to circuit clotting. Commonly used anticoagulants (i.e., heparin and citrate) can have side effects. The aim of this study was to describe our experience of using epoprostenol (a synthetic prostacyclin analog) as a sole anticoagulant during CRRT in children with liver disease.

DESIGN

Single-center, retrospective study, 2010-2019.

SETTING

Sixteen-bedded PICU within a United Kingdom supra-regional center for pediatric hepatology.

PATIENTS

Children with liver disease admitted to PICU who underwent CRRT anticoagulation with epoprostenol.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Regarding CRRT, we assessed filter life duration, effective 60-hour filter survival, and effective solute clearance. We also assessed the frequency of major or minor bleeding episodes per 1,000 hours of CRRT, the use of platelet and RBC transfusions, and the frequency of hypotensive episodes per 1,000 hours of CRRT. In the 10 years 2010-2019, we used epoprostenol anticoagulation during 353 filter episodes of CRRT, lasting 18,508 hours, in 96 patients (over 108 admissions). Median (interquartile range [IQR]) filter life was 48 (IQR 32-72) hours, and 22.9% of filters clotted. Effective 60-hour filter survival was 60.5%.We identified that 5.9% of filters were complicated by major bleeding (1.13 episodes per 1,000 hr of CRRT), 5.1% (0.97 per 1,000 hr) by minor bleeding, and 11.6% (2.22 per 1,000 hr) by hypotension. There were no differences in filter life or clotting between patients with acute liver failure and other liver diseases; there were no differences in rates of bleeding, hypotension, or transfusion when comparing patients with initial platelets of ≤ 50 × 109 per liter to those with a higher initial count.

CONCLUSIONS

Epoprostenol, or prostacyclin, as the sole anticoagulant for children with liver disease receiving CRRT in PICU, results in a good circuit life, and complications such as bleeding and hypotension are similar to reports using other anticoagulants, despite concerns about coagulopathy in this cohort.

Transient elastography and von Willebrand factor as predictors of portal hypertension and decompensation in children

Background & Aims

Von Willebrand factor antigen (vWFAg), a protein measured to test the level of vWF released from the vascular endothelium has gained much attention as a marker for portal hypertension (PHT) severity. The objectives of this study were to investigate the use of vWFAg as a biomarker along with liver and spleen stiffness measurements by transient elastography as potential predictors of clinically significant varices (CSV), variceal bleeding (VB) and decompensation in children with PHT.

Methods

This observational prospective cohort study included 117 children (median age 10 [IQR 6-14] years) who underwent oesophagogastroduodenoscopy between January'2012 to November'2021 and a validation group of 33 children who underwent the same procedure between December'2021 to March'2023. Measurements of vWFAg and glycoprotein Ib binding activity of VWF (GPIbR) were available in 97 patients in the study group and in all patients in the validation group.Results: vWFAg and GPIbR were significantly higher in children with CSV (223 IU/dl and 166 IU/dl; p = 0.015 and p = 0.04, respectively) and VB (218 IU/dl and 174 IU/dl; p = 0.077 and p = 0.03, respectively) than in those without CSV or VB, respectively. Ninety-six patients had liver and spleen stiffness measurements. Spleen stiffness was significantly higher in patients with CSV compared to those without CSV (p = 0.003). In a chronic liver disease subgroup, a predictive scoring tool based on vWFAg, GPIbR, platelet count, and spleen/liver stiffness measurements could predict CSV with an AUROC of 0.76 (p = 0.04).

Conclusions

This study suggests the predictive value of vWF for CSV and VB increases when combined with spleen stiffness, with AUROCs of 0.88 and 0.82, respectively. Hence, a combination of biomarkers could assist clinicians in diagnosing CSV, preventing unnecessary invasive procedures.

Impacts and implications

Surveillance endoscopies in children with portal hypertension (PHT) have their own risks and non-invasive markers, such as von Willebrand factor antigen, glycoprotein Ib binding activity of VWF (GPIbR), and transient elastography could be used to predict clinically significant varices, variceal bleeding and disease compensation in children with PHT. Such non-invasive markers for PHT and varices are lacking in the paediatric population. The results show that von Willebrand factor and GPIbR along with transient elastography can be used to formulate a scoring system which can be used as a clinical tool by paediatric hepatologists to monitor the progression of PHT and risk of bleeding, and hence to stratify the performance of invasive endoscopic procedures under general anaesthesia. However, there is a need to validate the scoring system in children with portal vein thrombosis and for hepatic decompensation in a multi-centre registry in the future.

Beyond Varices: Complications of Cirrhotic Portal Hypertension in Pediatrics

Complications of cirrhotic portal hypertension (PHTN) in children are broad and include clinical manifestations ranging from variceal hemorrhage, hepatic encephalopathy (HE), ascites, spontaneous bacterial peritonitis (SBP), and hepatorenal syndrome (HRS) to less common conditions such as hepatopulmonary syndrome, portopulmonary hypertension, and cirrhotic cardiomyopathy. The approaches to the diagnosis and management of these complications have become standard of practice in adults with cirrhosis with many guidance statements available. However, there is limited literature on the diagnosis and management of these complications of PHTN in children with much of the current guidance available focused on variceal hemorrhage. The aim of this review is to summarize the current literature in adults who experience these complications of cirrhotic PHTN beyond variceal hemorrhage and present the available literature in children, with a focus on diagnosis, management, and liver transplant decision making in children with cirrhosis who develop ascites, SBP, HRS, HE, and cardiopulmonary complications.

Consensus on the management of complications of cirrhosis of the liver in pediatrics

The Asociación Mexicana de Hepatología A.C. carried out the Consensus on the Management of Complications of Cirrhosis of the Liver in Pediatrics to provide physicians with useful information for treating said complications. A group of pediatric gastroenterologists and experts in nutrition, nephrology, and infectious diseases participated and reviewed the medical literature. The Delphi method was applied to obtain the level of agreement on the statements that were formulated. The statements were sent to the participants to be analyzed and voted upon, after which they were discussed in virtual sessions, and the final versions were produced. The aim of the consensus results was to issue indications for the management of pediatric patients with liver cirrhosis, to prevent or control complications.

Continuous Renal Replacement Therapy in Pediatric Patients With Acute Kidney Injury After Liver Transplantation

Objective

This study aimed to explore the clinical application of continuous renal replacement therapy (CRRT) in pediatric patients with acute kidney injury (AKI) after liver transplantation.

Methods

Pediatric patients who underwent liver transplantation were retrospectively investigated. Those who developed AKI within 1 year after the surgery were included and divided into a CRRT group and a non-CRRT group. The perioperative conditions and postoperative complications of the two groups were compared along with the prognoses of the groups to analyze the high-risk factors of the postoperative CRRT.

Results

189 (36.91%) patients developed AKI within 1 year after the liver transplantation surgery. There were 18 patients in the CRRT group and 171 in the non-CRRT group. The differences in the preoperative conditions were not statistically significant between the two groups. Compared with the non-CRRT group, patients in the CRRT group had significantly longer transplantation times, higher volumes of intraoperative hemorrhage, and increased incidence of postoperative unscheduled surgery, postoperative primary nonfunction of the transplanted liver, secondary liver transplantation, hepatic artery occlusion, and intestinal fistula (P < 0.05). Moreover, the proportion of patients in AKI stage 3 is higher in the CRRT group (83.33%) than that in the non-CRRT group (11.11%), P < 0.001. The median time to initiate CRRT was 10 days postoperatively, the median number of CRRT treatments per patient was 2 times, the average duration of each CRRT treatment was 10.1 h, and the average rate of the decrease in blood creatinine per treatment was 25.6%. Results of multivariate logistic regression analysis showed that AKI stage 3 [OR=40.000, 95%CI (10.598, 150.969), P = 0.016], postoperative unscheduled surgery [OR=6.269, 95%CI (3.051, 26.379), P = 0.007], and hepatic artery occlusion [OR = 17.682, 95%CI (1.707, 40.843), P = 0.001] were recognized as risk factors for postoperative AKI with CRRT therapy. The one- and two-year survival rates were 72.22% and 72.22% in the CRRT group, respectively; and 97.08% and 96.49% in the non-CRRT group, accordingly. There were statistically significant differences in the one- and two-year survival rates between the two groups (P < 0.001).

Conclusion

The incidence of AKI after liver transplantation in pediatric patients was high. Patients with AKI stage 3, hepatic artery occlusion, and underwent unscheduled surgery postoperatively were with a high likelihood of receiving CRRT, which was related to a lower one- and two-year survival rates. CRRT effectively improved the one- and two-year survival rates.

Acute Liver Failure in Children

Acute liver failure (ALF) in children, irrespective of cause, is a rapidly evolving catastrophic clinical condition that results in high mortality and morbidity without prompt identification and intervention. Massive hepatocyte necrosis impairs the synthetic, excretory, and detoxification abilities of the liver, with resultant coagulopathy, jaundice, metabolic disturbance, and encephalopathy. Extrahepatic organ damage, multiorgan failure, and death result from circulating inflammatory mediators released by the hepatocytes undergoing necrosis. There are yet no treatment options available for reversing or halting hepatocellular necrosis, thus current therapy focuses on supporting failing organs and preventing life threatening complications pending either spontaneous liver recovery or transplantation. The aims of this review are to define pediatric acute liver failure (PALF), understand the pathophysiologic processes that lead to multiorgan failure, to describe the consequences of a failing liver on extrahepatic organs, to enumerate the critical care challenges encountered during PALF management, and to describe pharmacologic and extracorporeal options available to support a critically ill child with ALF in the intensive care unit.

Preserved renal function during long-term follow-up in children with chronic liver disease

AIM

We have previously found well-maintained renal function in children with new-onset chronic liver disease. In this study, we investigated their renal function during long-term follow-up of the disease.

METHODS

In a study of 289 children with chronic liver disease, renal function was investigated as glomerular filtration rate (GFR) measured as clearance of inulin or iohexol. Yearly change in GFR was calculated based on a linear mixed model. The data were analysed with regard to different subgroups of liver disease and with regard to the outcome.

RESULTS

The initially well-preserved renal function remained so in most patients during the observation period, even in children with progressive liver disease leading to decompensation. The greatest fall in GFR occurred in patients with initial hyperfiltration. Cholestasis seemed to have a nephroprotective effect.

CONCLUSION

Chronic liver disease in childhood seems to have less impact on renal function than believed earlier, at least as long as the liver function remains compensated. Regular renal check-ups remain an essential tool for optimal patient care. Hyperfiltration seems to predict decline in renal function. Otherwise no further reliable prognostic markers were found in patients whose liver disease was not decompensated.

Trends in Survival for Pediatric Transplantation

OBJECTIVES

Progress in pediatric transplantation measured in the context of waitlist and posttransplant survival is well documented but falls short of providing a complete perspective for children and their families. An intent-to-treat analysis, in which we measure survival from listing to death regardless of whether a transplant is received, provides a more comprehensive perspective through which progress can be examined.

METHODS

Univariable and multivariable Cox regression was used to analyze factors impacting intent-to-treat survival in 12 984 children listed for heart transplant, 17 519 children listed for liver transplant, and 16 699 children listed for kidney transplant. The Kaplan-Meier method and log-rank test were used to assess change in waitlist, posttransplant, and intent-to-treat survival. Wait times and transplant rates were compared by using χ2 tests.

RESULTS

Intent-to-treat survival steadily improved from 1987 to 2017 in children listed for heart (hazard ratio [HR] 0.96, 95% confidence interval [CI] 0.96-0.97), liver (HR 0.95, 95% CI 0.94-0.97), and kidney (HR 0.97, 95% CI 0.95-0.99) transplant. Waitlist and posttransplant survival also improved steadily for all 3 organs. For heart transplant, the percentage of patients transplanted within 1 year significantly increased from 1987 to 2017 (60.8% vs 68.7%); however, no significant increase was observed in liver (68.9% vs 72.5%) or kidney (59.2% vs 62.7%) transplant.

CONCLUSIONS

Intent-to-treat survival, which is more representative of the patient perspective than individual metrics alone, steadily improved for heart, liver, and kidney transplant over the study period. Further efforts to maximize the donor pool, improve posttransplant outcomes, and optimize patient care while on the waitlist may contribute to future progress.

Blood Urea Nitrogen to Serum Albumin Ratio in the Prediction of Acute Kidney Injury of Patients with Rib Fracture in Intensive Care Unit

Background

We hypothesized that the blood urea nitrogen (BUN) to serum albumin ratio (BAR) could serve as an independent predictor for incident acute kidney injury (AKI) in intensive care unit (ICU) patients with rib fracture.

Methods

Rib fracture patients in ICU were extracted from Medical Information Mart for Intensive Care IV (MIMIC-IV v1.0) database. The primary outcome in this study was the incidence of AKI. Univariate and multivariate logistic regression analyses were used to determine the relationship between BAR and AKI and propensity score matching (PSM) and inverse probability of treatment weighting (IPTW) were also applied to assure the robustness of our results.

Results

The optimal cut-off value for BAR was 5.26 based on receiver operator characteristic curve. Among the 953 patients who diagnosed with rib fracture, 197 high-BAR group (≥5.26) patients and 197 low-BAR group (<5.26) patients who had similar propensity scores were finally included in the matched cohort. High-BAR group patients had a significantly higher incidence of AKI (odds ratio, OR, 3.85, 95% confidence index, 95% CI, 2.58–5.79, P<0.001) in the original cohort, in the matched cohort (OR, 4.47, 95% CI 2.71–7.53, P<0.001), and in the weighted cohort (OR, 4.28, 95% CI 2.80–6.53, P<0.001). Furthermore, BAR was superior to that of acute physiology score III for predicting AKI and could add more net benefit for incident AKI in critical care patients with rib fracture.

Conclusion

As an easily access and cost-effective parameter, BAR could serve as a good diagnostic predictor for AKI in ICU patients with rib fracture.

Multiple organ involvement and ICU considerations for the care of acute liver failure (ALF) and acute on chronic liver failure (ACLF) in children

Liver disease results in approximately 15,000 pediatric hospitalizations per year in the United States and is a significant burden to child health. Major etiologies of liver failure and indications for transplantation in children include: biliary atresia, metabolic/genetic conditions, toxins, infections, tumors, and immune-mediated liver/biliary injury. Children requiring transplantation are placed on the United Network of Organ Sharing waitlist including those with acute liver failure (ALF) and acute on chronic liver failure (ACLF). ALF is a clinical syndrome in which a previously healthy child develops rapid-onset hepatic dysfunction, and becomes critically ill with multiple organ dysfunction within days. ACLF, by contrast, is generally described as an acute decompensation of pre-existing chronic liver disease (CLD) brought on by a precipitating event, with higher risk of mortality. Children with ALF and ACLF receive multidisciplinary care in pediatric intensive care units (ICUs) due to multiple organ system involvement and high risk of decompensation in these patients. The care of these patients requires a holistic approach that addresses the complex interplay between hepatic and extra-hepatic organ systems. This review will define and describe ALF and ACLF in the pediatric population, and outline the effects of ALF and ACLF on individual organ systems with diagnostic and management considerations in the ICU while awaiting liver transplantation.

Hepatorenal syndrome in children: a review

Hepatorenal syndrome (HRS) occurs in patients with cirrhosis or fulminant hepatic failure and is a kind of pre-renal failure due to intense reduction of kidney perfusion induced by severe hepatic injury. While other causes of pre-renal acute kidney injury (AKI) respond to fluid infusion, HRS does not. HRS incidence is 5% in children with chronic liver conditions before liver transplantation. Type 1 HRS is an acute and rapidly progressive form that often develops after a precipitating factor, including gastrointestinal bleeding or spontaneous bacterial peritonitis, while type 2 is considered a slowly progressive form of kidney failure that often occurs spontaneously in chronic ascites settings. HRS pathogenesis is multifactorial. Cirrhosis causes portal hypertension; therefore, stasis and release of vasodilator substances occur in the hepatic vascular bed, leading to vasodilatation of splanchnic arteries and systemic hypotension. Many mechanisms seem to work together to cause this imbalance: splanchnic vasodilatation; vasoactive mediators; hyperdynamic circulation states and subsequent cardiac dysfunction; neuro-hormonal mechanisms; changes in sympathetic nervous system, renin-angiotensin system, and vasopressin. In patients with AKI and cirrhosis, fluid expansion therapy needs to be initiated as soon as possible and nephrotoxic drugs discontinued. Once HRS is diagnosed, pharmacological treatment with vasoconstrictors, mainly terlipressin plus albumin, should be initiated. If there is no response, other options can include surgical venous shunts and kidney replacement therapy. In this regard, extracorporeal liver support can be a bridge for liver transplantation, which remains as the ideal treatment. Further studies are necessary to investigate early biomarkers and alternative treatments for HRS.

Advances in management of end stage liver disease in children

End stage liver disease (ESLD) is an irreversible condition that is a management challenge to the paediatrician. The aetiology and natural history of ESLD in children is not only distinct from adults but also variable depending upon the age of presentation. Children are especially vulnerable to developmental delay, frailty and malnutrition. Nutritional support is the cornerstone of management of these children as it has a significant impact on the clinical course and survival, both before and after transplantation. Further, the complications of ESLD in children including but not limited to, ascites, portal hypertension, spontaneous bacterial peritonitis and encephalopathy raise unique management challenges. In this review we provide a concise review of and highlight recent advances in the management of paediatric ESLD.

Renal Function Parameters and Serum Sodium Enhance Prediction of Wait-List Outcomes in Pediatric Liver Transplantation

BACKGROUND AND AIMS

Reliance on exception points to prioritize children for liver transplantation (LT) stems from concerns that the Pediatric End-Stage Liver Disease (PELD) score underestimates mortality. Renal dysfunction and serum sodium disturbances are negative prognosticators in adult LT candidates and various pediatric populations, but are not accounted for in PELD. We retrospectively evaluated the effect of these parameters in predicting 90-day wait-list death/deterioration among pediatric patients (<12 years) listed for isolated LT in the United States between February 2002 and June 2018.

APPROACH AND RESULTS

Among 4,765 patients, 2,303 (49.3%) were transplanted, and 231 (4.8%) died or deteriorated beyond transplantability within 90 days of listing. Estimated glomerular filtration rate (eGFR) (hazard ratio [HR] 1.09 per 5-unit decrease, 95% confidence interval [CI] 1.06-1.10) and dialysis (HR 7.24, 95% CI 3.57-14.66) were univariate predictors of 90-day death/deterioration (P < 0.001). The long-term benefit of LT persisted in patients with renal dysfunction, with LT as a time-dependent covariate conferring a 2.4-fold and 17-fold improvement in late survival among those with mild and moderate-to-severe dysfunction, respectively. Adjusting for PELD, sodium was a significant nonlinear predictor of outcome, with 90-day death/deterioration risk increased at both extremes of sodium (HR 1.20 per 1-unit decrease below 137 mmol/L, 95% CI 1.16-1.23; HR per 1-unit increase above 137 mmol/L 1.13, 95% CI 1.10-1.17, P < 0.001). A multivariable model incorporating PELD, eGFR, dialysis, and sodium demonstrated improved performance and superior calibration in predicting wait-list outcomes relative to the PELD score.

CONCLUSIONS

Listing eGFR, dialysis, and serum sodium are potent, independent predictors of 90-day death/deterioration in pediatric LT candidates, capturing risk not accounted for by PELD. Incorporation of these variables into organ allocation systems may highlight patient subsets with previously underappreciated risk, augment ability of PELD to prioritize patients for transplantation, and ultimately mitigate reliance on nonstandard exceptions.

PCRRT Expert Committee ICONIC Position Paper on Prescribing Kidney Replacement Therapy in Critically Sick Children With Acute Liver Failure

Management of acute liver failure (ALF) and acute on chronic liver failure (ACLF) in the pediatric population can be challenging. Kidney manifestations of liver failure, such as hepatorenal syndrome (HRS) and acute kidney injury (AKI), are increasingly prevalent and may portend a poor prognosis. The overall incidence of AKI in children with ALF has not been well-established, partially due to the difficulty of precisely estimating kidney function in these patients. The true incidence of AKI in pediatric patients may still be underestimated due to decreased creatinine production in patients with advanced liver dysfunction and those with critical conditions including shock and cardiovascular compromise with poor kidney perfusion. Current treatment for kidney dysfunction secondary to liver failure include conservative management, intravenous fluids, and kidney replacement therapy (KRT). Despite the paucity of evidence-based recommendations concerning the application of KRT in children with kidney dysfunction in the setting of ALF, expert clinical opinions have been evaluated regarding the optimal modalities and timing of KRT, dialysis/replacement solutions, blood and dialysate flow rates and dialysis dose, and anticoagulation methods.

Pharmacological management of portal hypertension and its complications in children: lessons from adults and opportunities for the future

INTRODUCTION

Portal hypertension (PHT) and its complications in children are thought to be distinct from adult PHT in several areas, including the underlying bio-physiology of a child in which PHT develops, but also because of the pediatric-specific etiologies that drive disease progression. And yet pharmacologic approaches to PHT in children are mainly based on adult data, modified for pediatric practice. This reality has been driven by a lack of data specific to children.

AREAS COVERED

The authors discuss current therapeutic approaches to PHT in children, including management of acute gastrointestinal variceal bleed, pharmacotherapy in prophylaxis, and established and emerging therapies to combat systemic co-morbidities that result from PHT. The few areas where pediatric-specific data exist are highlighted and the many gaps in knowledge that remain unresolved are underscored.

EXPERT OPINION

Despite decades of experience, optimal management of pediatric PHT remains undefined. In large part, this can be directly linked to a lack of basic understanding related to the unique pathophysiology and natural history that defines PHT in children. As a result, meaningful research into the utility and effectiveness of pharmacotherapy in children with PHT remains in its infancy. Large, multi-center, prospective studies will be needed to begin to establish an infrastructure on which a pediatric-specific research agenda can be built.

Admission Characteristics Identify Risk of Pediatric Acute-on-Chronic Liver Failure

OBJECTIVES

Acute-on-chronic liver failure (ACLF) is well-studied in adults and characterized by decompensated cirrhosis, multi-organ failure, and early mortality. Studies of ACLF in children are limited. We sought to characterize the prevalence and clinical factors associated with pediatric ACLF (PACLF).

METHODS

A retrospective review of children 3 months to 18 years listed for liver transplantation and hospitalized for decompensated cirrhosis between January 2007 and December 2017 at a single pediatric hospital. Primary outcome was the development of PACLF, characterized as failure of at least 1 extrahepatic organ (mechanical ventilation, renal replacement therapy, vasoactive medications, grade III/IV hepatic encephalopathy). Characteristics were recorded for each hospitalization.

RESULTS

Sixty-six patients had 186 hospitalizations with mean age at admission 4.0 ± 5.6 years and diagnosis of biliary atresia (BA) in 65%. PACLF developed in 20 patients during 23 hospitalizations (12%) and respiratory failure was most common (17/23, 74%). Duration of intensive care unit stay, 13.1 ± 1.2 days versus 0.6 ± 0.6 days (P < 0.001) and length of stay, 24.3 ± 5.0 days versus 7.9 ± 1.9 days (P = 0.003) were longer in PACLF compared with non-PACLF. Mortality during PACLF hospitalizations was 22%. Clinical factors associated with PACLF were reported from a generalized linear mixed model and included increased admission creatinine (P < 0.0001), increased aspartate aminotransferase (AST) (P = 0.014), increased international normalized ration (INR) (P = 0.0015), and a positive blood culture (P = 0.007).

CONCLUSION

In this pediatric series, PACLF developed in 12% of hospitalizations and mortality was high. Admission creatinine, AST, INR, and presence of a positive blood culture were associated with PACLF development.

LCAT protects against Lipoprotein-X formation in a murine model of drug-induced intrahepatic cholestasis

Familial lecithin:cholesterol acyltransferase (LCAT) deficiency (FLD) is a rare genetic disease characterized by low HDL-C levels, low plasma cholesterol esterification, and the formation of Lipoprotein-X (Lp-X), an abnormal cholesterol-rich lipoprotein particle. LCAT deficiency causes corneal opacities, normochromic normocytic anemia, and progressive renal disease due to Lp-X deposition in the glomeruli. Recombinant LCAT is being investigated as a potential therapy for this disorder. Several hepatic disorders, namely primary biliary cirrhosis, primary sclerosing cholangitis, cholestatic liver disease, and chronic alcoholism also develop Lp-X, which may contribute to the complications of these disorders. We aimed to test the hypothesis that an increase in plasma LCAT could prevent the formation of Lp-X in other diseases besides FLD. We generated a murine model of intrahepatic cholestasis in LCAT-deficient (KO), wild type (WT), and LCAT-transgenic (Tg) mice by gavaging mice with alpha-naphthylisothiocyanate (ANIT), a drug well known to induce intrahepatic cholestasis. Three days after the treatment, all mice developed hyperbilirubinemia and elevated liver function markers (ALT, AST, Alkaline Phosphatase). The presence of high levels of LCAT in the LCAT-Tg mice, however, prevented the formation of Lp-X and other plasma lipid abnormalities in WT and LCAT-KO mice. In addition, we demonstrated that multiple injections of recombinant human LCAT can prevent significant accumulation of Lp-X after ANIT treatment in WT mice. In summary, LCAT can protect against the formation of Lp-X in a murine model of cholestasis and thus recombinant LCAT could be a potential therapy to prevent the formation of Lp-X in other diseases besides FLD.

Clinically Evident Portal Hypertension: An Operational Research Definition for Future Investigations in the Pediatric Population

Portal hypertension (PHT) is a major cause of morbidity and mortality in pediatric liver diseases. Thus, research into causes and disease modifiers in PHT in these conditions is vitally important. PHT is rarely directly or indirectly measured in the assessment of children with chronic liver disease. A straightforward, reproducible definition of PHT could be invaluable for consistently identifying patients with PHT and for grouping these patients according to their risk of complications from their disease. We propose the term Clinically Evident Portal Hypertension (CEPH) to denote clinical findings that demonstrate evidence of elevated portal pressure. When CEPH criteria are met, PHT is highly likely to be present, although it is likely that PHT exists for variable periods of time before meeting CEPH criteria. Use of this research definition of CEPH will allow for consistent identification of these patients by clinicians in nearly any clinical setting and serve as a clinical milepost that may dictate future prognosis in pediatric patients with cirrhosis.