Association of Acetaminophen (Paracetamol) Use with Severity and Outcomes in Patients with Viral Hepatitis-Associated Acute Liver Failure.

BACKGROUND/AIMS: Acute viral hepatitis (AVH) comprises 11% of acute liver failure (ALF) in North America while acetaminophen (APAP) toxicity represents 46%. Use of APAP to treat prodromal hepatitis symptoms is common. It is unknown if concurrent APAP use impacts liver injury in AVH-induced ALF. PATIENTS AND METHODS: In this prospective, multicenter cohort study, 356 patients meeting criteria for AVH including hepatitis A, B, EBV, and HSV, all leading to ALF (hepatic encephalopathy (HE) after acute illness, INR ≥ 1.5), or acute liver injury (ALI, INR >2.0, no HE) were reviewed for evidence of APAP use: APAP ingestion history or measurement of serum APAP level or APAP-CYS adducts, a specific biomarker released into blood with APAP injury. Patients were grouped by APAP exposure level, from High (measurable APAP levels or toxic APAP-CYS); Medium (therapeutic APAP-CYS); Low (history of APAP ingestion only and/or barely detectable APAP-CYS); or No Exposure recorded. RESULTS: 205/356 (57.5%) of AVH-ALF patients had evidence of APAP use: 87/356 (24%) demonstrated High or Medium exposures. The High/Medium group's aminotransferase and bilirubin levels resembled a mixed APAP-viral injury. Mortality was highest (51.6%, 21.4%, 28.8%, 30.5% and transplant-free survival (TFS) lowest (22.6%, 44.6%, 41.5%, 40.4%) in the High Exposure group compared to Medium, Low, and No Exposure groups. However, the specific comparisons of mortality and TFS between the High and No Exposure groups were not statistically different even after adjusting for baseline patient characteristics differences. CONCLUSIONS: APAP use in AVH-ALF is common and may negatively impact outcomes compared to little or no APAP exposure. Prospective studies of the most safe and effective dose of APAP to use in patients with AVH are needed.

Future directions in acute liver failure.

Acute liver failure (ALF) describes a clinical syndrome of rapid hepatocyte injury leading to liver failure manifested by coagulopathy and encephalopathy in the absence of pre-existing cirrhosis. The hallmark diagnostic features are a prolonged prothrombin time (ie, an international normalized ratio of prothrombin time of ≥1.5) and any degree of mental status alteration (HE). As a rare, orphan disease, it seemed an obvious target for a multicenter network. The Acute Liver Failure Study Group (ALFSG) began in 1997 to more thoroughly study and understand the causes, natural history, and management of ALF. Over the course of 22 years, 3364 adult patients were enrolled in the study registry (2614 ALF and 857 acute liver injury-international normalized ratio 2.0 but no encephalopathy-ALI) and >150,000 biosamples collected, including serum, plasma, urine, DNA, and liver tissue. Within the Registry study sites, 4 prospective substudies were conducted and published, 2 interventional ( N -acetylcysteine and ornithine phenylacetate), 1 prognostic [ 13 C-methacetin breath test (MBT)], and 1 mechanistic (rotational thromboelastometry). To review ALFSG's accomplishments and consider next steps, a 2-day in-person conference was held at UT Southwestern Medical Center, Dallas, TX, entitled "Acute Liver Failure: Science and Practice," in May 2022. To summarize the important findings in the field, this review highlights the current state of understanding of ALF and, more importantly, asks what further studies are needed to improve our understanding of the pathogenesis, natural history, and management of this unique and dramatic condition.

Autoimmune hepatitis presenting as acute liver failure: A 20-year retrospective review of North America.

Autoimmune hepatitis is a common cause of acute liver failure. Treatment includes steroids for acute liver injury and liver transplantation in those who fail to respond or develop acute liver failure. The aim of this study is to further characterize acute liver failure secondary to autoimmune hepatitis and identify variables that predict 21-day transplant-free survival. This study included adults hospitalized with acute liver failure enrolled in the Acute Liver Failure Study Group Registry between 1998 and 2019 from 32 centers within the US. The etiology of all cases was reviewed by the Adjudication Committee, and all cases identified as autoimmune hepatitis were included. Acute liver injury was defined as an INR ≥2.0 without encephalopathy and acute liver failure as INR ≥ 1.5 with encephalopathy. Laboratory and clinical data were reviewed. Variables significantly associated with 21-day transplant-free survival were used to develop a multivariable logistic regression model.  A total of 193 cases of acute liver failure secondary to autoimmune hepatitis were identified and reviewed. There were 161 patients (83.4%) diagnosed with acute liver failure on enrollment, and 32 (16.6%) developed acute liver failure during hospitalization. At 21 days, 115 (59.6%) underwent liver transplantation, 28 (14.5%) had transplant-free survival, and 46 (23.8%) died before liver transplantation. Higher admission values of bilirubin, INR, and coma grade were associated with worse outcomes. A prognostic index incorporating bilirubin, INR, coma grade, and platelet count had a concordance statistic of 0.84. Acute liver failure secondary to autoimmune hepatitis is associated with a high short-term mortality. We developed a model specifically for autoimmune hepatitis that may be helpful in predicting 21-day transplant-free survival and early identification of patients in need of expedited liver transplant evaluation.

Outcomes of patients with acute liver failure listed for liver transplantation: A multicenter prospective cohort analysis.

Liver transplantation (LT) is a life-saving treatment for patients with acute liver failure (ALF). Currently, there are few detailed data regarding long-term outcomes after LT for ALF. We combined prospective data from the Acute Liver Failure Study Group (ALFSG) Registry with those of the Scientific Registry of Transplant Recipients (SRTR) to assess outcomes among consecutive patients with ALF listed for LT. Cohort analysis of detailed pretransplantation data for patients listed for LT for ALF in the ALFSG Registry between January 1998 and October 2018 matched with transplantation-related data from the SRTR. Primary outcomes were 1- and 3-year post-LT patient survival. Secondary outcome was receipt of LT; independent associations with successful receipt of LT were determined using multivariable logistic regression. Of 624 patients with ALF listed for LT, 398 (64%) underwent LT, 100 (16%) died without LT, and 126 (20%) recovered spontaneously. Among LT recipients, etiologies included seronegative/indeterminate (22%), drug-induced liver injury (18%), acetaminophen overdose (APAP; 16%), and viral hepatitis (15%). The 1- and 3-year post-LT patient survival rates were 91% and 90%, respectively. Comparing those dying on the waiting list versus with those who received LT, the former had more severe multiorgan failure, reflected by increased vasopressor use (65% vs. 22%), mechanical ventilation (84% vs. 57%), and renal replacement therapy (57% vs. 30%; p < 0.0001 for all). After adjusting for relevant covariates, age (adjusted odds ratio [aOR] 1.02, 95% confidence interval [CI] 1.00-1.04), APAP etiology (aOR 2.72, 95% CI 1.42-5.23), requirement for vasopressors (aOR 4.19, 95% CI 2.44-7.20), Grade III/IV hepatic encephalopathy (aOR 2.47, 95% CI 1.29-4.72), and Model for End-Stage Liver Disease (MELD) scores (aOR 1.05, 95% CI 1.02-1.09; p < 0.05 for all) were independently associated with death without receipt of LT. Post-LT outcomes for ALF are excellent in this cohort of very ill patients. The development of multiorgan failure while on the transplantation list and APAP ALF etiology were associated with a lower likelihood of successful receipt of LT.

Generation of neutrophil extracellular traps in patients with acute liver failure is associated with poor outcome.

BACKGROUND AND AIMS: Acute liver failure (ALF) is characterized by significant changes in the hemostatic system and by systemic inflammation. The formation of neutrophil extracellular traps (NETs), in which an activated neutrophil expels its DNA, histones, and granular enzymes, such as myeloperoxidase (MPO), has been associated with immune-mediated and thrombotic diseases. We hypothesized that formation of NETs in patients with ALF contributes to progression of disease. APPROACH AND RESULTS: A total of 676 patients with ALF (international normalized ratio [INR], ≥1.5) or severe acute liver injury (ALI; INR, ≥2.0) were recruited from the U.S. ALF Study Group Registry between 2011 and 2018, of whom 308 patients (45.6%) had acetaminophen-induced ALF. Up to 21 days after admission, 483 patients (71.5%) survived without liver transplantation (LT). Levels of cell-free DNA (cfDNA) and the specific NET marker MPO-DNA complexes were measured in plasma samples obtained on admission and compared to levels in healthy controls. In addition, liver tissue obtained at transplantation of 20 ALF patients was stained for NETs. Levels of cfDNA were 7.1-fold, and MPO-DNA complexes 2.5-fold, higher in patients with ALF compared to healthy controls. cfDNA levels were not associated with 21-day transplant-free survival, but were higher in those patients with more-severe disease on admission, as reflected by various laboratory and clinical parameters. MPO-DNA levels were 30% higher in patients with ALF who died or required urgent LT. Liver tissue of ALF patients stained positive for NETs in 12 of 18 evaluable patients. CONCLUSIONS: Here, we provide evidence for NET formation in patients with ALF. Elevated plasma levels of MPO-DNA complexes in patients with ALF were associated with poor outcome, which suggests that NET formation contributes to disease progression.

Intensive Versus Standard Treatment of Hyperglycemia in Acute Ischemic Stroke Patient: A Randomized Clinical Trial Subgroups Analysis.

BACKGROUND: Benefit from blood glucose (BG) control during acute ischemic stroke may depend on glycemic parameters. We evaluated for associations between the SHINE (Stroke Hyperglycemia Insulin Network Effort) randomized treatment group and the SHINE predefined 90-day functional outcome, within-patient subgroups defined by various glycemic parameters. METHODS: The SHINE Trial randomized 1151 patients within 12 hours with acute ischemic stroke and hyperglycemia to standard (target BG 80-179 mg/dL) or intensive (target BG 80-130 mg/dL) BG control for 72 hours. We predefined 6 glycemic parameters: acute BG level, absence versus presence of diagnosed and undiagnosed diabetes, hemoglobin A1c, glycemic gap (acute BG-average daily hemoglobin A1c based BG), stress hyperglycemia ratio (acute BG/average daily hemoglobin A1c based BG), and BG variability (SD). Favorable functional outcome was defined by the SHINE Trial and based on the modified Rankin Scale score at 90 days, adjusted for stroke severity. We computed relative risks adjusted for baseline stroke severity and thrombolysis use. RESULTS: Likelihood for favorable outcome was lowest among patients with undiagnosed diabetes compared to patients with true nondiabetes (adjusted relative risk, 0.42 [99% CI, 0.19-0.94]). We did not find any relationship between the favorable outcome rate and baseline BG or any of the glycemic parameters. No differences between SHINE treatment groups were identified among any of these patient subgroups. CONCLUSIONS: In this exploratory subgroup analysis, intensive versus standard insulin treatment of hyperglycemia in acute ischemic stroke patient subgroups, did not influence the 90-day functional outcomes, nor did we identify associations between these glycemic parameters and 90-day functional outcomes.

VWF/ADAMTS13 Imbalance, But Not Global Coagulation or Fibrinolysis, Is Associated With Outcome and Bleeding in Acute Liver Failure.

BACKGROUND AND AIMS: Recent studies of acute liver failure (ALF) in man and animals have suggested that rebalanced hemostasis occurs, with distinct hypercoagulable features clinically evidenced by a low risk of bleeding. Rodent models have shown a link between intrahepatic microthrombus formation and progression of ALF. We sought to confirm these earlier findings in a large series of patients with well-characterized ALF from the Acute Liver Failure Study Group. APPROACH AND RESULTS: Citrated plasma samples taken on admission from 676 patients with ALF or acute liver injury (international normalized ratio ≥2.0 without hepatic encephalopathy) were used to determine levels of von Willebrand factor (VWF), a disintegrin and metalloproteinase with a thrombospondin type 1 motif, member 13 (ADAMTS13) activity, thrombomodulin-modified thrombin generation, and clot lysis time (CLT) and compared with the levels in 40 healthy controls. Patients had 3-fold increased VWF levels, 4-fold decreased ADAMTS13 activity, similar thrombin generating capacity, and 2.4-fold increased CLT, compared with controls. Increasing disease severity was associated with progressively more elevated VWF levels as well as hypofibrinolysis. Patients who died or underwent liver transplantation within 21 days of admission had higher VWF levels, lower ADAMTS13 activity, but similar thrombin generation and a similar proportion of patients with severe hypofibrinolysis, when compared with transplant-free survivors. Likewise, patients with bleeding complications had higher VWF levels and lower ADAMTS13 activity compared to those without bleeding. Thrombin generation and CLT did not differ significantly between bleeding and nonbleeding patients. CONCLUSIONS: Rebalanced hemostatic status was confirmed in a large cohort of patients with acute liver injury/ALF, demonstrating that VWF/ADAMTS13 imbalance is associated with poor outcome and bleeding. The association between VWF/ADAMTS13 imbalance and bleeding suggests that bleeding in ALF relates more to systemic inflammation than a primary coagulopathy.

Prognostic Value of the 13 C-Methacetin Breath Test in Adults with Acute Liver Failure and Non-acetaminophen Acute Liver Injury.

BACKGROUND AND AIMS: The 13 C-methacetin breath test (MBT) is a noninvasive, quantitative hepatic metabolic function test. The aim of this prospective, multicenter study was to determine the utility of initial and serial 13 C-MBT in predicting 21-day outcomes in adults with acute liver failure (ALF) and non-acetaminophen acute liver injury (ALI). APPROACH AND RESULTS: The 13 C-MBT BreathID device (Exalenz Biosciences, Ltd.) provided the percent dose recovery (PDR) for a duration of 60 minutes after administration of 13 C-methacetin solution as the change in exhaled 13 CO2 /12 CO2 compared with pre-ingestion ratio on study days 1, 2, 3, 5, and 7. Results were correlated with 21-day transplant-free survival and other prognostic indices. A total of 280 subjects were screened for enrollment between May 2016 and August 2019. Median age of the 62 enrolled patients with adequate data was 43 years, 79% were Caucasian, 76% had ALF with the remaining 24% having ALI. The mean PDR peak on day 1 or day 2 was significantly lower in nonsurvivors compared with transplant-free survivors (2.3%/hour vs. 9.1%/hour; P < 0.0001). In addition, serial PDR peaks were consistently lower in nonsurvivors versus survivors (P < 0.0001). The area under the receiver operating characteristic curve (AUROC) of the 13 C-MBT in the combined cohort was 0.88 (95% CI: 0.79-0.97) and higher than that provided by King's College (AUROC = 0.70) and Model for End-Stage Liver Disease scores (AUROC = 0.83). The 13 C-MBT was well tolerated with only two gastrointestinal adverse events reported. CONCLUSIONS: The 13 C-MBT is a promising tool to estimate the likelihood of hepatic recovery in patients with ALF and ALI. Use of the PDR peak data from the 13 C-MBT point-of-care test may assist with medical decision making and help avoid unnecessary transplantation in critically ill patients with ALF and ALI.

An Unsuccessful Randomized Trial of Percutaneous vs Endoscopic Drainage of Suspected Malignant Hilar Obstruction.

Percutaneous transhepatic biliary drainage (PTBD) and endoscopic retrograde cholangiopancreatography (ERCP) are widely accepted but competing approaches for the management of malignant obstruction at the hilum of the liver. ERCP is favored in the United States on the basis of high success rates for non-hilar indications, the perceived safety and superior tissue sampling capability of ERCP relative to PTBD, and the avoidance of external drains that are undesirable to patients. A recent randomized controlled trial (RCT) comparing the 2 modalities in patients with resectable hilar cholangiocarcinoma was terminated prematurely because of higher mortality in the PTBD group.1 In contrast, most observational data suggest that PTBD is superior for achieving complete drainage.2-6 Because the preferred procedure remains uncertain, we aimed to compare PTBD and ERCP as the primary intervention in patients with cholestasis due to malignant hilar obstruction (MHO).

Alcohol consumption is associated with the severity and outcome of acute liver injury/failure.

BACKGROUND & AIMS: Non-medical factors which contribute to the severity of acute liver failure (ALF) remain poorly defined. The association of alcohol consumption on the severity of presentation and outcome were determined in patients with ALF and acute liver injury (ALI) in a large, multicentre registry. METHODS: Alcohol consumption during the 6 months prior to study entry was analysed in 1170 patients enrolled in the ALF Study Group Registry. Consumption was categorized as none/minimal (<3 alcoholic beverages/week) or at least moderate (≥3/week). Clinical characteristics, the severity of liver injury at presentation (ALI or ALF) and outcome were compared. RESULTS: In patients with acetaminophen (APAP) overdose, at least moderate alcohol consumption was associated with higher peak aminotransferases, bilirubin, creatinine and INR on admission, compared to no/minimal consumption. In patients with non-APAP ALI/ALF, at least moderate alcohol consumption was associated with higher peak aminotransferases and creatinine. In APAP, non-APAP or all aetiologies, at least moderate alcohol consumption was associated with a 75%, 89% and 82% higher odds, respectively, of presenting as ALF rather than ALI (all P < .005). At least moderate alcohol consumption increased the odds of death by 45% (P = .01) across all aetiologies. In multivariate analysis, older age, non-Caucasian race, peak INR, peak bilirubin and at least moderate alcohol consumption were significantly associated with death. Finally, in Kaplan-Meier analysis of patients with all aetiologies, at least moderate alcohol consumption was associated with decreased time-dependent survival (P = .002). CONCLUSION: Alcohol consumption adversely affects the presentation and outcome of both APAP- and non-APAP-induced ALI/ALF.

Bleeding complications in acute liver failure.

In patients with acute liver failure (ALF), elevated prothrombin time and thrombocytopenia can fuel a perception of a bleeding tendency. However, the incidence, site, risk factors, and clinical significance of bleeding complications have not been quantified in a large cohort of patients with ALF. We studied 1,770 adult patients enrolled in the ALF Study Group Registry between 1998 and 2016. Bleeding complications and blood component transfusions were collected for 7 days after admission. The relationship of bleeding complications to 21-day mortality was assessed. Despite a median international normalized ratio of 2.7 and platelet count of 96 × 109 /L on admission, bleeding complications were observed in only 187 patients (11%), including 173 spontaneous and 22 postprocedural bleeding episodes. Eighty-four percent of spontaneous bleeding episodes were from an upper gastrointestinal source and rarely resulted in red blood cell transfusion. Twenty patients experienced an intracranial bleed; half of these occurred spontaneously and half after intracranial pressure monitor placement, and this was the proximate cause of death in 20% and 50%, respectively. Bleeders and patients who received red blood cell transfusions were more acutely ill from extrahepatic organ system failure but not from hepatocellular failure. Consistent with this observation, bleeding complications were associated with lower platelet counts but not higher international normalized ratio. Transfusion of any blood component was associated with nearly 2-fold increased death or need for liver transplantation at day 21, but bleeding complications were the proximate cause of death in only 5% of cases. CONCLUSIONS: Despite a perceived bleeding diathesis, clinically significant bleeding is uncommon in patients with ALF; bleeding complications in patients with ALF are markers of severe systemic inflammation rather than of coagulopathy and so portend a poor prognosis. (Hepatology 2018;67:1931-1942).

Safety, tolerability, and pharmacokinetics of l-ornithine phenylacetate in patients with acute liver injury/failure and hyperammonemia.

Cerebral edema remains a significant cause of morbidity and mortality in patients with acute liver failure (ALF) and has been linked to elevated blood ammonia levels. l-ornithine phenylacetate (OPA) may decrease ammonia by promoting its renal excretion as phenylacetylglutamine (PAGN), decreasing the risk of cerebral edema. We evaluated the safety, tolerability, and pharmacokinetics of OPA in patients with ALF and acute liver injury (ALI), including those with renal failure. Forty-seven patients with ALI/ALF and ammonia ≥60 µM were enrolled. Patients received OPA in a dose escalation scheme from 3.3 g every 24 hours to 10 g every 24 hours; 15 patients received 20 g every 24 hours throughout the infusion for up to 120 hours. Plasma phenylacetate (PA) concentrations were uniformly below target (<75 µg/mL) in those receiving 3.3 g every 24 hours (median [interquartile range] 5.0 [5.0] µg/mL), and increased to target levels in all but one who received 20 g every 24 hours (150 [100] µg/mL). Plasma [PAGN] increased, and conversion of PA to PAGN became saturated, with increasing OPA dose. Urinary PAGN clearance and creatinine clearance were linearly related (r = 0.831, P < 0.0001). Mean ammonia concentrations based on the area under the curve decreased to a greater extent in patients who received 20 g of OPA every 24 hours compared with those who received the maximal dose of 3.3 or 6.7 g every 24 hours (P = 0.046 and 0.022, respectively). Of the reported serious adverse events (AEs), which included 11 deaths, none was attributable to study medication. The only nonserious AEs possibly related to study drug were headache and nausea/vomiting. CONCLUSION: OPA was well-tolerated in patients with ALI/ALF, and no safety signals were identified. Target [PA] was achieved at infusion rates of 20 g every 24 hours, leading to ammonia excretion in urine as PAGN in proportion to renal function. Randomized, controlled studies of high-dose OPA are needed to determine its use as an ammonia-scavenging agent in patients with ALF. (Hepatology 2018;67:1003-1013).

BiMM forest: A random forest method for modeling clustered and longitudinal binary outcomes.

Clustered binary outcomes and datasets with many predictor variables are frequently encountered in clinical research (e.g. longitudinal studies). Generalized linear mixed models (GLMMs) typically employed for clustered endpoints have challenges for some scenarios, particularly for complex datasets which contain many interactions among predictors and nonlinear predictors of outcome. We propose a new method called Binary Mixed Model (BiMM) forest, which combines random forest and GLMM methodology. BiMM forest offers a flexible and stable method which naturally models interactions among predictors and can be employed in the setting of clustered data. Simulation studies show that BiMM forest achieves similar or superior prediction accuracy compared to standard random forest, GLMMs and its tree counterpart (BiMM tree) for clustered binary outcomes. The method is applied to a real dataset from the Acute Liver Failure Study Group. BiMM forest offers an alternative method for modeling clustered binary outcomes which may be applied in myriad research settings.

Outcomes in Adults With Acute Liver Failure Between 1998 and 2013: An Observational Cohort Study.

BACKGROUND: Acute liver failure (ALF) is a rare syndrome of severe, rapid-onset hepatic dysfunction-without prior advanced liver disease-that is associated with high morbidity and mortality. Intensive care and liver transplantation provide support and rescue, respectively. OBJECTIVE: To determine whether changes in causes, disease severity, treatment, or 21-day outcomes have occurred in recent years among adult patients with ALF referred to U.S. tertiary care centers. DESIGN: Prospective observational cohort study. (ClinicalTrials .gov: NCT00518440). SETTING: 31 liver disease and transplant centers in the United States. PATIENTS: Consecutively enrolled patients-without prior advanced liver disease-with ALF (n = 2070). MEASUREMENTS: Clinical features, treatment, and 21-day outcomes were compared over time annually for trends and were also stratified into two 8-year periods (1998 to 2005 and 2006 to 2013). RESULTS: Overall clinical characteristics, disease severity, and distribution of causes remained similar throughout the study period. The 21-day survival rates increased between the two 8-year periods (overall, 67.1% vs. 75.3%; transplant-free survival [TFS], 45.1% vs. 56.2%; posttransplantation survival, 88.3% vs. 96.3% [P < 0.010 for each]). Reductions in red blood cell infusions (44.3% vs. 27.6%), plasma infusions (65.2% vs. 47.1%), mechanical ventilation (65.7% vs. 56.1%), and vasopressors (34.9% vs. 27.8%) were observed, as well as increased use of N-acetylcysteine (48.9% vs. 69.3% overall; 15.8% vs. 49.4% [P < 0.001] in patients with ALF not due to acetaminophen toxicity). When examined longitudinally, overall survival and TFS increased throughout the 16-year period. LIMITATIONS: The duration of enrollment, the number of patients enrolled, and possibly the approaches to care varied among participating sites. The results may not be generalizable beyond such specialized centers. CONCLUSION: Although characteristics and severity of ALF changed little over 16 years, overall survival and TFS improved significantly. The effects of specific changes in intensive care practice on survival warrant further study. PRIMARY FUNDING SOURCE: National Institutes of Health.

Thrombocytopenia Is Associated With Multi-organ System Failure in Patients With Acute Liver Failure.

BACKGROUND & AIMS: Acute liver failure (ALF) is a syndrome characterized by an intense systemic inflammatory response (SIRS) and multi-organ system failure (MOSF). Platelet-derived microparticles increase in proportion to the severity of the SIRS and MOSF, and are associated with poor outcome. We investigated whether patients with ALF develop thrombocytopenia in proportion to the SIRS, MOSF, and poor outcome. METHODS: In a retrospective study, we collected data on the post-admission platelet counts of 1598 patients included in the ALF Study Group Registry from 1998 through October 2012. We investigated correlations between platelet counts and clinical features of ALF, laboratory test results, and outcomes. Of the patients studied, 752 (47%) survived without liver transplantation, 390 (24%) received liver transplants, and 517 (32%) died. RESULTS: In patients with SIRS, platelet counts decreased 2 to 7 days after admission, compared with patients without SIRS (P ≤ .001). Patients with abnormal levels of creatinine, phosphate, lactate, or bicarbonate had significantly lower platelet counts than patients with normal levels of these laboratory values (all P ≤ .001). The decrease in platelets during days 1 to 7 after admission was proportional to the grade of hepatic encephalopathy and requirement for vasopressor and renal replacement therapy. Although platelet numbers decreased after admission in the overall population, platelets were significantly lower 2 to 7 days after admission in patients with outcomes of death or liver transplantation than in patients who made spontaneous recoveries and survived. In contrast, international normalized ratios over time were not associated with SIRS, laboratory test results associated with poor outcomes, grade of hepatic encephalopathy, or requirement for renal replacement therapy. CONCLUSIONS: The development of thrombocytopenia in patients with ALF is associated with the development of MOSF and poor outcome. We speculate that SIRS-induced activation of platelets, yielding microparticles, results in clearance of platelet remnants and subsequent thrombocytopenia.

Development of a Model to Predict Transplant-free Survival of Patients With Acute Liver Failure.

BACKGROUND & AIMS: Patients with acute liver failure (ALF) have a high risk of death that can be substantially reduced with liver transplantation. It is a challenge to predict which patients with ALF will survive without liver transplant because available prognostic scoring systems are inadequate. We devised a mathematical model, using a large dataset collected by the Acute Liver Failure Study Group, which can predict transplant-free survival in patients with ALF. METHODS: We performed a retrospective analysis of data from 1974 subjects who met criteria for ALF (coagulopathy and hepatic encephalopathy within 26 weeks of the first symptoms, without pre-existing liver disease) enrolled in the Acute Liver Failure Study Group database from January 1, 1998 through June 11, 2013. We randomly assigned the subjects to development and validation cohorts. Data from the development cohort were analyzed to identify factors associated with transplant-free survival (alive without transplantation by 21 days after admission to the study). Statistically significant variables were used to create a multivariable logistic regression model. RESULTS: Most subjects were women (70%) and white (78%); acetaminophen overdose was the most common cause (48% of subjects). The rate of transplant-free survival was 50%. Admission values of hepatic encephalopathy grade, ALF etiology, vasopressor use, and log transformations of bilirubin and international normalized ratio were significantly associated with transplant-free survival, based on logistic regression analysis. In the validation cohort, the resulting model predicted transplant-free survival with a C statistic value of 0.84, 66.3% accuracy (95% confidence interval, 63.1%-69.4%), 37.1% sensitivity (95% confidence interval, 32.5%-41.8%), and 95.3% specificity (95% confidence interval, 92.9%-97.1%). CONCLUSIONS: Using data from the Acute Liver Failure Study Group, we developed a model that predicts transplant-free survival of patients with ALF based on easily identifiable hospital admission data. External validation studies are required.

Determinants of outcome among patients with acute liver failure listed for liver transplantation in the United States.

Analyses of outcomes after acute liver failure (ALF) have typically included all ALF patients regardless of whether they were listed for liver transplantation (LT). We hypothesized that limiting analysis to listed patients might provide novel insights into factors associated with outcome, focusing attention on disease evolution after listing. Listed adult ALF patients enrolled in the US Acute Liver Failure Study Group registry between 2000 and 2013 were analyzed to determine baseline factors associated with 21-day outcomes after listing. We classified 617 patients (36% of overall ALF group) by 3-week outcome after study admission: 117 were spontaneous survivors (SSs; survival without LT), 108 died without LT, and 392 underwent LT. Only 22% of N-acetyl-p-aminophenol (APAP) ALF patients were listed; however, this group of 173 patients demonstrated greater illness severity: higher coma grades and more patients requiring ventilator, vasopressor, or renal replacement therapy support. Only 62/173 (36%) of APAP patients received a graft versus 66% for drug-induced liver injury patients, 86% for autoimmune-related ALF, and 71% for hepatitis B-related ALF. APAP patients were more likely to die than non-APAP patients (24% versus 17%), and the median time to death was sooner (2 versus 4.5 days). Despite greater severity of illness, the listed APAP group still had a SS rate of 40% versus 11% for non-APAP causes (P < 0.001). APAP outcomes evolve rapidly, mainly to SS or death. Patients with APAP ALF listed for LT had the highest death rate of any etiology, whereas more slowly evolving etiologies yielded higher LT rates and, consequently, fewer deaths. Decisions to list and transplant must be made early in all ALF patients, particularly in those with APAP ALF.

Intramuscular versus intravenous therapy for prehospital status epilepticus.

BACKGROUND: Early termination of prolonged seizures with intravenous administration of benzodiazepines improves outcomes. For faster and more reliable administration, paramedics increasingly use an intramuscular route. METHODS: This double-blind, randomized, noninferiority trial compared the efficacy of intramuscular midazolam with that of intravenous lorazepam for children and adults in status epilepticus treated by paramedics. Subjects whose convulsions had persisted for more than 5 minutes and who were still convulsing after paramedics arrived were given the study medication by either intramuscular autoinjector or intravenous infusion. The primary outcome was absence of seizures at the time of arrival in the emergency department without the need for rescue therapy. Secondary outcomes included endotracheal intubation, recurrent seizures, and timing of treatment relative to the cessation of convulsive seizures. This trial tested the hypothesis that intramuscular midazolam was noninferior to intravenous lorazepam by a margin of 10 percentage points. RESULTS: At the time of arrival in the emergency department, seizures were absent without rescue therapy in 329 of 448 subjects (73.4%) in the intramuscular-midazolam group and in 282 of 445 (63.4%) in the intravenous-lorazepam group (absolute difference, 10 percentage points; 95% confidence interval, 4.0 to 16.1; P<0.001 for both noninferiority and superiority). The two treatment groups were similar with respect to need for endotracheal intubation (14.1% of subjects with intramuscular midazolam and 14.4% with intravenous lorazepam) and recurrence of seizures (11.4% and 10.6%, respectively). Among subjects whose seizures ceased before arrival in the emergency department, the median times to active treatment were 1.2 minutes in the intramuscular-midazolam group and 4.8 minutes in the intravenous-lorazepam group, with corresponding median times from active treatment to cessation of convulsions of 3.3 minutes and 1.6 minutes. Adverse-event rates were similar in the two groups. CONCLUSIONS: For subjects in status epilepticus, intramuscular midazolam is at least as safe and effective as intravenous lorazepam for prehospital seizure cessation. (Funded by the National Institute of Neurological Disorders and Stroke and others; ClinicalTrials.gov number, ClinicalTrials.gov NCT00809146.).