Diagnosis and management of pediatric acute liver failure: consensus recommendations of the Indian Society of Pediatric Gastroenterology, Hepatology, and Nutrition (ISPGHAN)

Timely diagnosis and management of pediatric acute liver failure (PALF) is of paramount importance to improve survival. The Indian Society of Pediatric Gastroenterology, Hepatology, and Nutrition invited national and international experts to identify and review important management and research questions. These covered the definition, age appropriate stepwise workup for the etiology, non-invasive diagnosis and management of cerebral edema, prognostic scores, criteria for listing for liver transplantation (LT) and bridging therapies in PALF. Statements and recommendations based on evidences assessed using the modified Grading of Recommendations Assessment, Development and Evaluation (GRADE) system were developed, deliberated and critically reappraised by circulation. The final consensus recommendations along with relevant published background information are presented here. We expect that these recommendations would be followed by the pediatric and adult medical fraternity to improve the outcomes of PALF patients.

Hemorrhagic Complications of Invasive Intracranial Pressure Monitor Placement in Acute Liver Failure: Outcomes of a Single-Center Protocol and Comprehensive Literature Review

BACKGROUND

Elevated intracranial pressure due to cerebral edema is associated with very poor survival in patients with acute liver failure (ALF). Placing an intracranial pressure monitor (ICPm) aids in management of intracranial hypertension, but is associated with potentially fatal hemorrhagic complications related to the severe coagulopathy associated with ALF.

METHODS

An institutional Acute Liver Failure Clinical Protocol (ALF-CP) was created to correct ALF coagulopathy prior to placing parenchymal ICP monitoring bolts. We aimed to investigate the frequency, severity, and clinical significance of hemorrhagic complications associated with ICPm bolt placement in the setting of an ALF-CP. All assessed patients were managed with the ALF-CP and had rigorous radiologic follow-up allowing assessment of the occurrence and chronology of hemorrhagic complications. We also aimed to compare our outcomes to other studies that were identified through a comprehensive review of the literature.

RESULTS

Fourteen ALF patients were included in our analysis. There was no symptomatic hemorrhage after ICP monitor placement though four patients were found to have minor intraparenchymal asymptomatic hemorrhages after liver transplant when the ICP monitor had been removed, making the rate of radiographically identified clinically asymptomatic hemorrhage 28.6%. These results compare favorably to those found in a comprehensive review of the literature which revealed rates as high as 17.5% for symptomatic hemorrhages and 30.4% for asymptomatic hemorrhage.

CONCLUSION

This study suggests that an intraparenchymal ICPm can be placed safely in tertiary referral centers which utilize a protocol such as the ALF-CP that aggressively corrects coagulopathy. The ALF-CP led to advantageous outcomes for ICPm placement with a 0% rate of symptomatic and low rate of asymptomatic hemorrhagic complications, which compares well to results reported in other series. A strict ICPm placement protocol in this setting facilitates management of ALF patients with cerebral edema during the wait time to transplantation or spontaneous recovery.

Management of Hepatic Coagulopathy in Bleeding and Nonbleeding Patients: An Evidence-Based Review

Patients with varying degrees of hepatic dysfunction often present with presumed bleeding diathesis based on interpretation of routine measures of coagulation (prothrombin time [PT], international normalized ratio [INR], and activated partial thromboplastin time). However, standard markers of coagulation do not reflect the actual bleeding risk in this population and may lead to inappropriate administration of hemostatic agents and blood products. The concept of "rebalanced hemostasis" explains both the risk of bleeding and clotting seen in patients with liver dysfunction. The role of pharmacologic agents and blood products for prevention of bleeding during high-risk procedures and treatment of clinically significant bleeding remains unclear. Viscoelastic measurements of the clotting cascade provide information about platelets, fibrinogen/fibrin polymerization, coagulation factors, and fibrinolysis that might better represent hemostasis in vivo and may better inform management strategies. Due to the paucity of available data, firm recommendations for the use of blood products and pharmacologic agents in patients with hepatic coagulopathies are lacking, and thus, these products should not be routinely administered. Traditional laboratory tests such as PT/INR should not be the sole determinant of potential interventions. Rather, clinicians should assess factors such as the severity of bleed or bleeding risk of the procedure, the patient's risk of thromboembolism, and the strength of available evidence for specific agents and blood products to guide decision-making.

Intensive Care Management of Acute Liver Failure: Considerations While Awaiting Liver Transplantation

Acute liver failure is a unique clinical phenomenon characterized by abrupt deterioration in liver function and altered mentation. The development of high-grade encephalopathy and multisystem organ dysfunction herald poor prognosis. Etiologic-specific treatments and supportive measures are routinely employed; however, liver transplantation remains the only chance for cure in those who do not spontaneously recover. The utility of artificial and bioartificial assist therapies as supportive care-to allow time for hepatic recovery or as a bridge to liver transplantation-has been examined but studies have been small, with mixed results. Given the severity of derangements, intensive critical care is needed to successfully bridge patients to transplant, and evaluation of candidates occurs rapidly in parallel with serial reassessments of operative fitness. Psychosocial assessment is often suboptimal and relative contraindications to transplant, such as ventilator-dependence may be overlooked. While often employed to guide evaluation, no single prognostic model discriminates those who will spontaneously recover and those who will require transplant. The purpose of this review will be to summarize approaches in critical care, prognostic modeling, and medical evaluation of the acute liver failure transplant candidate.

Protocol based invasive intracranial pressure monitoring in acute liver failure: feasibility, safety and impact on management

Background

Acute liver failure (ALF) may result in elevated intracranial pressure (ICP). While invasive ICP monitoring (IICPM) may have a role in ALF management, these patients are typically coagulopathic and at risk for intracranial hemorrhage (ICH). Contemporary ICP monitoring techniques and coagulopathy reversal strategies may be associated with a lower risk of hemorrhage. Our objective was to evaluate the safety, feasibility, impact on clinical management and outcomes associated with protocol-directed use of IICPM in ALF.

Methods

Adult patients admitted between June 2011 and October 2016, with ALF and grade-4 encephalopathy with a reasonable likelihood of survival, were eligible for IICPM. The coagulopathy reversal protocol included administration of recombinant Factor VIIa (rFVIIa) and desmopressin, a goal platelet count >50,000/mm³ and fibrinogen >100 mg/dL. Monitor insertion was performed within an hour of the rFVIIa dose. Only intraparenchymal monitors were used. Computed tomography of the brain was performed prior to and within 24 hours of monitor placement. Outcomes of interest included ICH, sustained intracranial hypertension, therapeutic intensity level (TIL) for ICP management, mortality and functional outcome on the Glasgow Outcome Scale (GOS) at discharge and 6 months.

Results

A total of 24/37 patients (65%) with ALF underwent IICPM. The most common reason for exclusion was encephalopathy grade <4. Four patients underwent liver transplantation. There was one asymptomatic ICH following IICPM, in a patient who had an excellent outcome. Sustained intracranial hypertension occurred in 13/24 monitored patients (54%), 5/24 (21%) required extreme measures (TIL-4) for ICP control, which were successful in 4 patients: 12/24 patients (50%) died but only 4 deaths (17%) were attributed to intracranial hypertension. Six of the 8 survivors with 6-month follow up had good functional outcome (GOS >3).

Conclusions

Protocol-directed use of IICPM in ALF is feasible, associated with a low incidence of serious complications and has a significant impact on clinical management.

Drug-Induced Acute Liver Failure

Drug-induced acute liver failure (ALF) disproportionately affects women and nonwhites. It is most frequently caused by antimicrobials and to a lesser extent by complementary and alternative medications, antiepileptics, antimetabolites, nonsteroidals, and statins. Most drug-induced liver injury ALF patients have hepatocellular injury pattern. Cerebral edema and intracranial hypertension are the most serious complications of ALF. Other complications include coagulopathy, sepsis, metabolic derangements, and renal, circulatory, and respiratory dysfunction. Although advances in intensive care have improved outcome, ALF has significant mortality without liver transplantation. Liver-assist devices may provide a bridge to transplant or to spontaneous recovery.

Value of Preoperative Hemostasis Testing in Patients with Liver Disease for Perioperative Hemostatic Management

Preoperative hemostasis testing may have limited use in patients with liver disease, and an abnormal platelet count, prothrombin time, activated partial thromboplastin time, and fibrinogen level should not trigger prophylactic transfusion of blood product components.

Mathematical model and calculation to predict the effect of prophylactic plasma transfusion on change in international normalized ratio in critically ill patients with coagulopathy

BACKGROUND

Plasma transfusion is often used prophylactically in patients with coagulopathy. However, the doses transfused may not be adequate to normalize hemostatic tests, which are commonly used as surrogate markers in practice. Currently, there is no reliable way to predict the posttransfusion international normalized ratio (INR) after plasma transfusion. Therefore, our aim was to develop and validate a formula that can reliably estimate post-plasma transfusion INR.

STUDY DESIGN AND METHODS

A compartmental model was developed using demographic (sex, height, weight) and laboratory variables (hematocrit [Hct], INRinitial , and plasma volume transfused). The formula was validated using a data set from a multicenter trial conducted between May 2010 and June 2013 in critically ill, nonbleeding patients with coagulopathy, receiving prophylactic plasma transfusions. INR was measured just before and immediately after plasma transfusion.

RESULTS

Initial plasma volume is calculated using the patient's Hct and blood volume (derived from Nadler's formula). The estimated immediate posttransfusion INR is then calculated as [Formula: see text] There was a significant agreement between the model predictions and the actual INR measurements after transfusion. A total of 83% of the predictions were within the acceptable range of variation. Furthermore, there was no proportional difference or systemic bias between the predictions and the actual INR measurements.

CONCLUSION

This mathematical formula estimates posttransfusion INR after a certain volume of plasma transfusion with a good predictive ability. This formula, which only requires basic demographic and laboratory variables, may help the physicians to determine the volume of plasma required for a specific target INR in stable, nonbleeding patients.

Monitoring of hematological and hemostatic parameters in neurocritical care patients

Anemia and bleeding are paramount concerns in neurocritical care and often relate to the severity of intracranial hemorrhage. Anemia is generally associated with worse outcomes, and efforts to minimize anemia through reduced volume of blood sampled are encouraged. Point-of-care-testing reliably detects the use of non-steroidal anti-inflammatory drugs that may worsen bleeding and reduce platelet activity, particularly in patients with intracerebral hemorrhage. How best to monitor the effect of platelet transfusion or platelet-activating therapy is not well studied. For patients known to take novel oral anticoagulants, drug-specific coagulation tests before neurosurgical intervention are prudent.

Outcomes and complications of intracranial pressure monitoring in acute liver failure: a retrospective cohort study

OBJECTIVE

To determine if intracranial pressure monitor placement in patients with acute liver failure is associated with significant clinical outcomes.

DESIGN

Retrospective multicenter cohort study.

SETTING

Academic liver transplant centers comprising the U.S. Acute Liver Failure Study Group.

PATIENTS

Adult critically ill patients with acute liver failure presenting with grade III/IV hepatic encephalopathy (n = 629) prospectively enrolled between March 2004 and August 2011.

INTERVENTION

Intracranial pressure monitored (n = 140) versus nonmonitored controls (n = 489).

MEASUREMENTS AND MAIN RESULTS

Intracranial pressure monitored patients were younger than controls (35 vs 43 yr, p < 0.001) and more likely to be on renal replacement therapy (52% vs 38%, p = 0.003). Of 87 intracranial pressure monitored patients with detailed information, 44 (51%) had evidence of intracranial hypertension (intracranial pressure > 25 mm Hg) and overall 21-day mortality was higher in patients with intracranial hypertension (43% vs 23%, p = 0.05). During the first 7 days, intracranial pressure monitored patients received more intracranial hypertension-directed therapies (mannitol, 56% vs 21%; hypertonic saline, 14% vs 7%; hypothermia, 24% vs 10%; p < 0.03 for each). Forty-one percent of intracranial pressure monitored patients received liver transplant (vs 18% controls; p < 0.001). Overall 21-day mortality was similar (intracranial pressure monitored 33% vs controls 38%, p = 0.24). Where data were available, hemorrhagic complications were rare in intracranial pressure monitored patients (4 of 56 [7%]; three died). When stratifying by acetaminophen status and adjusting for confounders, intracranial pressure monitor placement did not impact 21-day mortality in acetaminophen patients (p = 0.89). However, intracranial pressure monitor was associated with increased 21-day mortality in nonacetaminophen patients (odds ratio, ~ 3.04; p = 0.014).

CONCLUSIONS

In intracranial pressure monitored patients with acute liver failure, intracranial hypertension is commonly observed. The use of intracranial pressure monitor in acetaminophen acute liver failure did not confer a significant 21-day mortality benefit, whereas in nonacetaminophen acute liver failure, it may be associated with worse outcomes. Hemorrhagic complications from intracranial pressure monitor placement were uncommon and cannot account for mortality trends. Although our results cannot conclusively confirm or refute the utility of intracranial pressure monitoring in patients with acute liver failure, patient selection and ancillary assessments of cerebral blood flow likely have a significant role. Prospective studies would be required to conclusively account for confounding by illness severity and transplant.

Cost-Effectiveness Analysis of Plasma Versus Recombinant Factor VIIa for Placing Intracranial Pressure Monitors in Pretransplant Patients With Acute Liver Failure

Both plasma- and recombinant activated factor VII (rFVIIa)-based algorithms can be used to correct coagulopathy in preliver transplant patients with acute liver failure requiring intracranial pressure monitor (ICPM) placement. A decision model was created to compare the cost-effectiveness of these methods. A 70-kg patient could receive either 1 round of plasma followed by coagulation testing or 2 units of plasma and 40 μg/kg rFVIIa. Intracranial pressure monitor is placed without coagulation testing after rFVIIa administration. In the plasma algorithm, the probability of ICPM placement was estimated based on expected international normalized ratio (INR) after plasma administration. Risks of rFVIIa thrombosis and transfusion reactions were also included. The model was run for patients with INRs ranging from 2 to 6 with concomitant adjustments to model parameters. The model supported the initial use of rFVIIa for ICPM placement as a cost-effective treatment when INR ≥2 (with incremental cost-effectiveness ratio of at most US$7088.02).

Neurologic manifestations of acute liver failure

Fulminant hepatic failure presents with a hepatic encephalopathy and may progress to coma and often brain death from cerebral edema. This natural progression in severe cases contributes to early mortality, but outcome can be good if liver transplantation is appropriately timed and increased intracranial pressure (ICP) is managed. Neurologists and neurosurgeons have become more involved in these very challenging patients and are often asked to rapidly identify patients who are at risk of cerebral edema, to carefully select the patient population who will benefit from invasive ICP monitoring, to judge the correct time to start monitoring, to participate in treatment of cerebral edema, and to manage complications such as intracranial hemorrhage or seizures. This chapter summarizes the current multidisciplinary approach to fulminant hepatic failure and how to best bridge patients to emergency liver transplantation.

Recombinant activated factor VII in patients with acute liver failure with UNOS Status 1A: a single tertiary academic centre experience

BACKGROUND AND OBJECTIVES

Recombinant activated factor VII (rFVIIa) is often used in off-label indications, including many situations in which the patients are at risk of thrombosis. In this study, we retrospectively reviewed the use of rFVIIa in patients with acute liver failure - UNOS Status 1A (ALF-1A) to determine its efficacy and safety profile.

MATERIALS AND METHODS

Using the transplantation records, all adult patients with ALF-1A were identified from 6/2001 to 3/2009. From patients' medical charts, rFVIIa dose, blood component usage, short-term outcomes [length of intensive care unit (ICU) and hospital stay, ability to undergo orthotopic liver transplant (OLT) and in-hospital survival rate] and adverse events were examined.

RESULTS

Forty-two patients with ALF-1A were identified. Fifteen patients received rFVIIa with doses ranging between 24·4 μg/kg and 126·8 μg/kg. Three patients received two doses of rFVIIa. The age, baseline activated partial thromboplastin time (aPTT) and platelet (PLT) count were not statistically different between the group receiving rFVIIa versus the group that did not. However, the prothrombin time (PT) was significantly higher in the rFVIIa group. Although the rFVIIa group stayed in the ICU longer and required significant more blood products during admission, there was no statistical difference between the two groups in terms of length of hospital stay, ability to undergo OLT and survival rate. There was no increase in complications, including thrombosis, after receiving rFVIIa.

CONCLUSION

Recombinant activated factor VII (rFVIIa) appears to be safe in patients with ALF-1A, but to elucidate its full role, a randomized controlled trial would be ideal.

Clinical Usefulness of Recombinant Activated Factor VII in Patients with Liver Failure Undergoing Invasive Procedures

Objective:

To evaluate the use of recombinant activated factor VII (rFVIIa) in patients with liver failure undergoing invasive procedures.

Methods:

An OVID/MEDUNE and PubMed search (1997-June 2011) was performed to identify literature on the use of rFVIIa to reduce bleeding risk in patients with liver failure undergoing invasive procedures.

Study Selection and Data Extraction:

English-language data evaluating the efficacy of rFVIIa to reverse coagulopathies prior to invasive procedures in patients with liver disease were included.

Data Synthesis:

Following administration of rFVIIa, prothrombin time (PT) and international normalized ratio (INR) response is within 30 minutes. Doses ranging from 20 to 120 μg/kg have been studied, with a reduction in PT seen in a dose-dependent manner. One study in patients with no bleeding administered 5, 20, and 80 μg/kg sequentially during a 24-day period. All doses provided reversal of prolonged PT within 10 minutes, and the duration was dose-dependent. In a study of 15 patients with fulminant liver failure, requiring intracranial pressure monitor placement, a rFVIIa dose of 40 μg/kg was compared to fresh frozen plasma. In patients who received rFVIIa, the PT and INR normalized, compared to none of the patients in the fresh frozen plasma group.

Conclusions:

Retrospective and prospective data demonstrate that rFVIIa effectively reverses elevated PT and INR, reducing the risk of bleeding and safely facilitating invasive procedures. Based on available data, a dose of 20-40 μg/kg 30 minutes prior to an invasive procedure should be considered in patients with acute or chronic liver failure at risk for bleeding complications. A major limitation of rFVIIa use is the high cost of therapy. A prospective, randomized trial could help determine the appropriate dose of rFVIIa, timing of dose in relationship to procedure, and usefulness of subsequent doses.

Acute liver failure: current practice and recent advances

ALF is an important cause of liver-related morbidity and mortality. Advances in the management of ICH and SIRS, and cardiorespiratory, metabolic, and renal support have improved the outlook of such patients. Early transfer to a liver transplant center is essential. Routine use of NAC is recommended for patients with early hepatic encephalopathy, irrespective of the etiology. The role of hypothermia remains to be determined. Liver transplantation plays a critical role, particularly for those with advanced encephalopathy. Several detoxification and BAL support systems have been developed to serve as a bridge to transplantation or to spontaneous recovery. However, such systems lack sufficient reliability and efficacy to be applied routinely in clinical practice. Hepatocyte and stem cell transplantation may provide valuable adjunctive therapy in the future.