Reducing paracetamol overdoses

Liquid Chromatography-Tandem Mass Spectrometry Analysis of Acetaminophen Covalent Binding to Glutathione S-Transferases

Acetaminophen (APAP)-induced hepatotoxicity is the most common cause of acute liver failure in the Western world. APAP is bioactivated to N-acetyl p-benzoquinone imine (NAPQI), a reactive metabolite, which can subsequently covalently bind to glutathione and protein thiols. In this study, we have used liquid chromatography-tandem mass spectrometry (LC-MS/MS) to characterize NAPQI binding to human glutathione S-transferases (GSTs) in vitro. GSTs play a crucial role in the detoxification of reactive metabolites and therefore are interesting target proteins to study in the context of APAP covalent binding. Recombinantly-expressed and purified GSTs were used to assess NAPQI binding in vitro. APAP biotransformation to NAPQI was achieved using rat liver microsomes or human cytochrome P450 Supersomes in the presence of GSTA1, M1, M2, or P1. Resulting adducts were analyzed using bottom-up proteomics, with or without LC fractionation prior to LC-MS/MS analysis on a quadrupole-time-of-flight instrument with data-dependent acquisition (DDA). Targeted methods using multiple reaction monitoring (MRM) on a triple quadrupole platform were also developed by quantitatively labeling all available cysteine residues with a labeling reagent yielding isomerically-modified peptides following enzymatic digestion. Seven modified cysteine sites were confirmed, including Cys112 in GSTA1, Cys78 in GSTM1, Cys115 and 174 in GSTM2, as well as Cys15, 48, and 170 in GSTP1. Most modified peptides could be detected using both untargeted (DDA) and targeted (MRM) approaches, however the latter yielded better detection sensitivity with higher signal-to-noise and two sites were uniquely found by MRM.

Predicting daily outcomes in acetaminophen-induced acute liver failure patients with machine learning techniques

BACKGROUND/OBJECTIVE

Assessing prognosis for acetaminophen-induced acute liver failure (APAP-ALF) patients during the first week of hospitalization often presents significant challenges. Current models such as the King's College Criteria (KCC) and the Acute Liver Failure Study Group (ALFSG) Prognostic Index are developed to predict outcome using only a single time point on hospital admission. Models using longitudinal data are not currently available for APAP-ALF patients. We aim to develop and compare performance of prediction models for outcomes during the first week of hospitalization for APAP-ALF patients.

METHODS

Models are developed for the ALFSG registry data to predict longitudinal outcomes for 1042 APAP-ALF patients enrolled 01/1998-02/2016. The primary outcome is defined as daily low versus high coma grade. Accuracy in prediction of outcome (AC), sensitivity (SN), specificity (SP) and area under the receiver operating curve (AUC) are compared between the following models: classification and regression tree, random forest, frequentist generalized linear mixed model (GLMM), Bayesian GLMM, BiMM tree, and BiMM forest using original and imputed datasets.

RESULTS

BiMM tree offers predictive (test set) 63% AC, 72% SP and 53% SN for the original dataset, whereas BiMM forest offers predictive (test set) 69% AC, 63% SP and 74% SN for the imputed dataset. BiMM tree has the highest AUC for the original testing dataset (0.697), whereas BiMM forest and standard random forest have the highest AUC for the imputed testing dataset (0.749). The three most important predictors of daily outcome for the BiMM tree are pressor use, bilirubin and creatinine. The BiMM forest model identifies lactate, ammonia and ALT as the three most important predictors of outcome.

CONCLUSIONS

BiMM tree offers a prognostic tool for APAP-ALF patients, which has good accuracy and simple interpretation of predictors which are consistent with clinical observations. BiMM tree and forest models are developed using the first week of in-patient data and are appropriate for predicting outcome over time. While the BiMM forest has slightly higher predictive AC, the BiMM tree model is simpler to use at the bedside.

Absolute quantitation of acetaminophen-modified human serum albumin in acute liver failure patients by liquid chromatography/tandem mass spectrometry

RATIONALE

Acetaminophen (APAP) is a well-known analgesic, deemed a very safe over-the-counter medication. However, it is also the main cause of acute liver failure (ALF) in the Western world, via the formation of its reactive metabolite, N-acetyl p-benzoquinone imine (NAPQI), and its covalent attachment to liver proteins. The aim of this study was to develop a sensitive and robust quantitative assay to monitor APAP-protein binding to human serum albumin (HSA) in patient samples.

METHODS

A combination of isotope dilution, peptic digestion and solid-phase extraction coupled to liquid chromatography/multiple reaction monitoring (LC/MRM) was employed. An external calibration curve with surrogate modified protein spiked into blank serum was used for absolute quantitation. Samples were analyzed by LC/MRM to measure the modified active site peptide of HSA. The LC/MRM assay was validated and successfully applied to serum samples from patients suffering from APAP-induced ALF.

RESULTS

Accuracy ranged from 83.8-113.3%, within-run coefficient of variation (CV) ranged from 0.3-6.9%, and total CVs from 1.6-10.6%. Patient samples ranged from 0.12-3.91 nmol/mL NAPQI-HSA; in-between the assay dynamic range of 0.11-50.13 nmol/mL serum. In vivo median concentrations were found to be 0.62 nmol/mL and 0.91 nmol/mL for non-spontaneous survivors (n = 25) and individuals with irreversible liver damage (n = 10), respectively (p-value = 0.028), demonstrating significant potential as a biomarker for ALF outcome.

CONCLUSIONS

A fast and sensitive assay was developed to accurately quantify NAPQI-HSA as a biomarker for APAP-related covalent binding in human serum.

Current Evidence for Extracorporeal Liver Support Systems in Acute Liver Failure and Acute-on-Chronic Liver Failure

Artificial (nonbiological) extracorporeal liver support devices aim to remove albumin-bound and water-soluble toxins to restore and preserve hepatic function and mitigate or limit the progression of multiorgan failure while hepatic recovery or liver transplant occurs. The following beneficial effects have been documented: improvement of jaundice, amelioration of hemodynamic instability, reduction of portal hypertension, and improvement of hepatic encephalopathy. The only randomized prospective multicenter controlled trial to show an improvement in transplant-free survival was for high-volume plasmapheresis. Biological (cell-based) extracorporeal liver support systems aim to support the failing liver through detoxification and synthetic function and warrant further study for safety and benefit.

Elevated FABP1 serum levels are associated with poorer survival in acetaminophen-induced acute liver failure

Acetaminophen (APAP)-induced acute liver failure (ALF) is associated with significant mortality. Traditional prognostic scores lack sensitivity. Serum liver-type fatty acid binding protein (FABP1) early (day 1) or late (day 3-5) levels are associated with 21-day mortality in the absence of liver transplant. Serum samples from 198 APAP-ALF patients (nested case-control study with 99 survivors, 99 nonsurvivors) were analyzed by enzyme-linked immunosorbent assay with clinical data from the US Acute Liver Failure Study Group registry (1998-2014). APAP-ALF survivors had significantly lower serum FABP1 levels early (238.6 versus 690.8 ng/mL, P < 0.0001) and late (148.4 versus 612.3 ng/mL, P < 0.0001) compared with nonsurvivors. FABP1 > 350 ng/mL was associated with significantly higher risk of death at early (P = 0.0004) and late (P < 0.0001) time points. Increased serum FABP1 early (log FABP1 odds ratio = 1.31, P = 0.027) and late (log FABP1 odds ratio = 1.50, P = 0.005) were associated with significantly increased 21-day mortality after adjusting for significant covariates (Model for End-Stage Liver Disease, vasopressor use). Areas under the receiver operating characteristic curve for early and late multivariable models were 0.778 and 0.907, respectively. The area under the receiver operating characteristic curve of the King's College criteria (early, 0.552 alone, 0.711 with FABP1; late, 0.604 alone, 0.797 with FABP1) and the Acute Liver Failure Study Group prognostic index (early, 0.686 alone, 0.766 with FABP1; late, 0.711 alone, 0.815 with FABP1) significantly improved with the addition of FABP1 (P < 0.002 for all).

CONCLUSION

In patients with APAP-ALF, FABP1 may have good potential to discriminate survivors from nonsurvivors and may improve models currently used in clinical practice; validation of FABP1 as a clinical prediction tool in APAP-ALF warrants further investigation. (Hepatology 2017;65:938-949).

Detection of Ophthalmic Acid in Serum from Acetaminophen-Induced Acute Liver Failure Patients Is More Frequent in Non-Survivors

Background/Aim

Acetaminophen (APAP) hepatotoxicity is related to the formation of N-acetyl-p-benzoquinone imine (NAPQI), which is detoxified through conjugation with reduced glutathione (GSH). Ophthalmic acid (OA) is an analogue of GSH in which cysteine is replaced with 2-aminobutyrate. Metabolomics studies of mice with APAP-induced acute liver failure (APAP-ALF) identified OA as a marker of oxidative stress and hepatic GSH consumption. The aim of the current study was to determine whether OA is detectable in APAP-ALF human patients either early (day 2) or late (day 4) and whether OA levels were associated with in-hospital survival in the absence of liver transplant.

Methods

Serum samples from 130 APAP-ALF patients (82 survivors, 48 non-survivors) were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and correlated with clinical data from the United States Acute Liver Failure Study Group (US ALFSG) Registry (2004–2011).

Results

Survivors had significantly lower admission bilirubin (4.2 vs. 5.7 mg/dl) and lactate levels (3.3 vs. 6.5 μmol/l, p<0.05 for all). During the first 7 days of the study, survivors were less likely to require mechanical ventilation (55% vs. 88%), vasopressor support (9.8% vs. 67%) or renal replacement therapy (26% vs. 63%, p< 0.001 for all). Non-survivors were more likely to have detectable OA levels early (31% vs. 15%, p = 0.034) and late (27% vs. 11%, p = 0.02). However there were no significant differences in mean OA levels between non-survivors and survivors (early 0.48 vs. 0.36, late 0.43 vs. 0.37, P > 0.5 for all).

Conclusion

OA was detectable more frequently in APAP-ALF non-survivors but mean OA levels were not associated with survival. The routine clinical administration of N-acetyl cysteine could replenish GSH levels and prevent OA production.

Emergency department visits for acetaminophen overdose: a Canadian population-based epidemiologic study (1997–2002)

Objective:

We describe the epidemiology of emergency department (ED) visits for acetaminophen overdose in a large Canadian health region, with a focus on sociodemographic risk factors and temporal trends.

Methods:

Patients presenting to an ED in the Calgary Health Region (population ~ 1.1 million) for acetaminophen overdose between 1997 and 2002 were identified using regional administrative data.

Results:

A total of 2699 patients made 3015 ED visits for acetaminophen overdose between 1997 and 2002, corresponding to an age- and sex-adjusted incidence of 45.7 per 100 000 population. Alcohol-related disorders were common (19%) and overdose rates were higher in females, younger patients, Aboriginals and social assistance recipients. The incidence decreased from 52.6 per 100 000 in 1997 to 35.1 per 100 000 in 2002 (34% relative reduction;p&lt; 0.0005). When classified according to suicidal intent, the rates of intentional and unintentional overdose (69% and 25% of all overdoses, respectively) showed similar temporal trends. A marked seasonality was observed, with a peak in spring and early summer.

Conclusions:

ED visit rates for acetaminophen overdose fell between 1997 and 2002. High-risk groups, including young females and marginalized populations, may benefit from preventive and educational initiatives.

Predicting outcome on admission and post-admission for acetaminophen-induced acute liver failure using classification and regression tree models

Background/Aim

Assessing prognosis for acetaminophen-induced acute liver failure (APAP-ALF) patients often presents significant challenges. King’s College (KCC) has been validated on hospital admission, but little has been published on later phases of illness. We aimed to improve determinations of prognosis both at the time of and following admission for APAP-ALF using Classification and Regression Tree (CART) models.

Methods

CART models were applied to US ALFSG registry data to predict 21-day death or liver transplant early (on admission) and post-admission (days 3-7) for 803 APAP-ALF patients enrolled 01/1998–09/2013. Accuracy in prediction of outcome (AC), sensitivity (SN), specificity (SP), and area under receiver-operating curve (AUROC) were compared between 3 models: KCC (INR, creatinine, coma grade, pH), CART analysis using only KCC variables (KCC-CART) and a CART model using new variables (NEW-CART).

Results

Traditional KCC yielded 69% AC, 90% SP, 27% SN, and 0.58 AUROC on admission, with similar performance post-admission. KCC-CART at admission offered predictive 66% AC, 65% SP, 67% SN, and 0.74 AUROC. Post-admission, KCC-CART had predictive 82% AC, 86% SP, 46% SN and 0.81 AUROC. NEW-CART models using MELD (Model for end stage liver disease), lactate and mechanical ventilation on admission yielded predictive 72% AC, 71% SP, 77% SN and AUROC 0.79. For later stages, NEW-CART (MELD, lactate, coma grade) offered predictive AC 86%, SP 91%, SN 46%, AUROC 0.73.

Conclusion

CARTs offer simple prognostic models for APAP-ALF patients, which have higher AUROC and SN than KCC, with similar AC and negligibly worse SP. Admission and post-admission predictions were developed.

Key Points

• Prognostication in acetaminophen-induced acute liver failure (APAP-ALF) is challenging beyond admission

• Little has been published regarding the use of King’s College Criteria (KCC) beyond admission and KCC has shown limited sensitivity in subsequent studies

• Classification and Regression Tree (CART) methodology allows the development of predictive models using binary splits and offers an intuitive method for predicting outcome, using processes familiar to clinicians

• Data from the ALFSG registry suggested that CART prognosis models for the APAP population offer improved sensitivity and model performance over traditional regression-based KCC, while maintaining similar accuracy and negligibly worse specificity

• KCC-CART models offered modest improvement over traditional KCC, with NEW-CART models performing better than KCC-CART particularly at late time points

Therapeutic hypothermia in acute liver failure: a multicenter retrospective cohort analysis

The benefit of therapeutic hypothermia (TH) in acute liver failure (ALF) has not been previously demonstrated in a controlled fashion. This study sought to determine the impact of TH on 21-day survival and complications in ALF patients at high risk for cerebral edema. This was a retrospective cohort study of ALF patients in the US Acute Liver Failure Study Group with grade III or IV hepatic encephalopathy. TH (32°C-35°C) was used in 97 patients (8%); 1135 (92%) who were not cooled were controls. Intracranial pressure was monitored in 38 TH ALF patients (39.2% versus 22% of controls, P < 0.001). Rates of bleeding (12% for both) and bloodstream (17% versus 18%) and tracheal infections (21% versus 23%, P > 0.5 for all) were similar. Unadjusted 21-day overall (62% versus 60%) and transplant-free survival rates (45% versus 39%, P > 0.4 for both) were similar. Multivariate models were created for acetaminophen (APAP) patients (n = 582) and non-APAP patients (n = 613). For APAP patients, the Model for End-Stage Liver Disease [MELD; odds ratio (OR) = 0.91 per increment, 95% confidence interval (CI) = 0.89-0.94, P < 0.001] and vasopressors (OR = 0.16, 95% CI = 0.11-0.24, P < 0.001) were associated with decreased 21-day spontaneous survival. Survival was improved with TH in APAP patients who were <25 years old (age of 25 years: OR = 2.735, 95% CI = 1.001-7.467) but worsened for APAP patients who were 64 years old or older (age of 64 years: OR = 0.167, 95% CI = 0.028-0.999). For non-APAP patients, MELD (OR = 0.93 per increment, 95% CI = 0.91-0.95, P < 0.001) and vasopressors (OR = 0.60, 95% CI = 0.40-0.90, P = 0.01) were associated with worse outcomes, whereas TH had no impact (P = 0.93). In conclusion, TH in ALF was not associated with increased bleeding or infections. Although young APAP ALF patients may benefit, TH did not consistently affect 21-day survival. A prospective trial is required to clarify the utility of TH in ALF patients.

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.

Paracetamol overdose in Victoria remains a significant health-care burden

BACKGROUND AND AIM

Paracetamol is the most frequently used analgesic in Australia and can be purchased without a prescription. We aimed to investigate the epidemiology and outcome of paracetamol overdoses occurring in Victoria, Australia.

METHODS

The Victorian admitted episode dataset was examined for all patients who had a diagnosis of paracetamol poisoning (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification [ICD-10-AM]: T39.1) or paracetamol adverse effect in therapeutic use (Y45.5) from July 1, 2000 to June 30, 2007. Data extracted included all ICD-10 codes related to their admissions, gender, age range, date of admission, and cause of death (if applicable).

RESULTS

Over 7 years, there was a total of 14,662 hospital admissions for paracetamol overdose with a mean of 2095 cases per year. Accidental overdoses comprised 15% (n = 2149) of cases. The overdose rate fell from 46 cases per 100,000 in 2001 to 39 cases per 100,000 in 2006 (P < 0.001). Most overdoses occurred in women (71%), and patients between 15 and 50 years old comprised 78% of all cases. Complications and mortality were relatively uncommon, with only 26 deaths directly attributable to paracetamol overdose over the 7 years. No child under 15 years old died from their overdose.

CONCLUSION

Admission to Victorian hospitals with paracetamol overdose presents an enormous and in many cases preventable health-care burden. Fortunately, there has been a gradual fall in admissions, and most cases appear relatively benign. Further reductions in overdose could be achieved with increased awareness by physicians and the general public regarding the potential for accidental overdose, and increasing funding for mental health initiatives.

The predictive value of hospital admission serum alanine transaminase activity in patients treated for paracetamol overdose

BACKGROUND

Paracetamol is a major cause of poisoning. Treatment decisions are predominately based on the dose ingested and a timed blood paracetamol concentration because most patients present to hospital soon after overdose, before hepatotoxicity can be confirmed/excluded using serum alanine transaminase (ALT). Nonetheless, ALT is measured at hospital presentation; we investigated its value in predicting hepatotoxicity.

METHODS

From March 2011 to May 2012, patients admitted to the Royal Infirmary of Edinburgh for paracetamol overdose treatment were identified. We determined the value of admission ALT (below or above our upper limit of normal-50 IU/l) at predicting three endpoints: 1-doubling of ALT; 2-peak ALT >1000 IU/l; 3-peak international normalized ratio (INR) >2.

RESULTS

From 500 patients, 410 met the entry criteria; 264 presented within 8 h of overdose, 54 between 8 and 24 h, 53 after 24 h and 39 were staggered ingestions. Admission ALT was increased in 71. For endpoint 1 (ALT doubling), the positive predictive value (PPV) of admission ALT was 19% [95% confidence interval (CI) 12-30] with a negative predictive value (NPV) of 98% (95% CI 96-99); endpoint 2 (ALT >1000 IU/l: PPV 23% (95% CI 14-34) and NPV 100% (95% CI 99-100) and for endpoint 3 (INR >2): PPV 14% (95% CI 7-25) and NPV of 100% (95% CI 99-100). The NPV remained high when only late presenters were included.

CONCLUSION

Admission ALT within the normal range has a high NPV and could be used, alone or in combination with newer biomarkers, to identify lower risk patients at hospital presentation.

Population prevalence of high dose paracetamol in dispensed paracetamol/opioid prescription combinations: an observational study

Background

Paracetamol (acetaminophen) is generally considered a safe medication, but is associated with hepatotoxicity at doses above doses of 4.0 g/day, and even below this daily dose in certain populations.

Methods

The Nova Scotia Prescription Monitoring Program (NSPMP) in the Canadian province of Nova Scotia is a legislated organization that collects dispensing information on all out-of-hospital prescription controlled drugs dispensed for all Nova Scotia residents. The NSPMP provided data to track all paracetamol/opioids redeemed by adults in Nova Scotia, from July 1, 2005 to June 30, 2010. Trends in the number of adults dispensed these prescriptions and the numbers of prescriptions and tablets dispensed over this period were determined. The numbers and proportions of adults who filled prescriptions exceeding 4.0 g/day and 3.25 g/day were determined for the one-year period July 1, 2009 to June 30, 2010. Data were stratified by sex and age (<65 versus 65+).

Results

Both the number of prescriptions filled and the number of tablets dispensed increased over the study period, although the proportion of the adult population who filled at least one paracetamol/opioid prescription was lower in each successive one-year period. From July 2009 to June 2010, one in 12 adults (n = 59,197) filled prescriptions for over 13 million paracetamol/opioid tablets. Six percent (n = 3,786) filled prescriptions that exceeded 4.0 g/day and 18.6% (n = 11,008) exceeded 3.25 g/day of paracetamol at least once. These findings exclude non-prescription paracetamol and paracetamol–only prescribed medications.

Conclusions

A substantial number of individuals who redeem prescriptions for paracetamol/opioid combinations may be at risk of paracetamol-related hepatotoxicity. Healthcare professionals must be vigilant when prescribing and dispensing these medications in order to reduce the associated risks.

A randomized, double-blind comparison shows the addition of oxygenated glycerol triesters to topical mentholated cream for the treatment of acute musculoskeletal pain demonstrates incremental benefit over time

BACKGROUND

Topical analgesics are important products in the armamentarium for pain relief.

METHODS AND FINDINGS

This study compared a topical analgesic product containing menthol to the same product with the addition of oxygenated glycerol triesters (OGTs) (also called essential oxygen oil) in 66 healthy adult subjects with acute musculoskeletal pain. Patients were randomized in a single-center, double-blind study to receive mentholated cream (MC) only or MC containing OGTs. Patients self-reported their pain intensity, lifestyle limitations, and evaluation of the mobility of the painful joint or muscle at baseline and three times daily over a seven-day course on a 100-mm visual analog scale (VAS). Patients in both groups experienced statistically significant pain relief on Day 8 over baseline, with the MC plus OGT-treated group reporting statistically significantly greater pain relief than the MC group (P = 0.016). In addition, patients treated with the combination product experienced an incremental decrease in pain during each of the 7 days of treatment in addition, and they had lower VAS scores and greater lifestyle and mobility improvements than the MC group. Both products were well tolerated with no serious adverse events reported and no signs of significant skin reactions in either group.

CONCLUSION

Based on this study, a MC containing OGTs is safe, effective, and provided significantly better pain relief than MC alone. The combination of oxygenated glycerol trimesters and MC provided significant pain relief and offered continued improvement in pain relief over time.

Acute liver failure in Scotland between 1992 and 2009; incidence, aetiology and outcome

AIM

To describe incidence, aetiology and outcome data for Scotland since the inception of the Scottish Liver Transplant Unit (SLTU) in 1992.

BACKGROUND

Acute liver failure (ALF) is a rare but frequently fatal condition. Few studies have adequate patient numbers to draw convincing conclusions over demographic features, aetiology and outcome.

DESIGN

Statistical analysis of prospectively collected data on aetiology, demographic, clinical and outcome of all admissions, including those with ALF, to the SLTU.

METHODS

Incidence data presented for admissions and ALF. Descriptive frequencies for aetiology, clinical, demographic and outcome data presented; including split analysis for paracetamol and non-paracetamol aetiologies. Univariate and multivariate analysis of admission factors predictive of outcome is described.

RESULTS

Nine hundred and forty-nine patients were admitted to the SLTU between 1992 and 2009. Five hundred and twenty-four patients had ALF. The annual incidence of ALF in the Scottish population is 0.62 per 100,000 and paracetamol overdose (POD) was the largest causative factor; responsible for 0.43 cases of ALF per 100,000 population per year. The odds ratio (OR) of transplantation or death was 0.47 in the POD group compared to other aetiologies; yet of not being a transplant candidate having met the Kings College Hospital poor prognostic criteria OR was 4.9. Of admissions listed for transplant 76.0% were transplanted. Of those listed and not transplanted mortality was approaching 100% and 76.1% of those transplanted survived to discharge.

CONCLUSION

This large, prospective, single centre study with a defined geographical area and well-recorded population provides accurate data regarding ALF between 1992 and 2009.

Medical and psychiatric outcomes for patients transplanted for acetaminophen-induced acute liver failure: a case-control study

BACKGROUND

Acetaminophen-induced hepatotoxicity is the most common cause of acute liver failure (ALF) in the UK. Patients often consume the drug with suicidal intent or with a background of substance dependence.

AIMS AND METHODS

We compared the severity of pretransplant illness, psychiatric co-morbidity, medical and psychosocial outcomes of all patients who had undergone liver transplantation (LT) emergently between 1999-2004 for acetaminophen-induced ALF (n=36) with age- and sex-matched patients undergoing emergent LT for non-acetaminophen-induced ALF (n=35) and elective LT for chronic liver disease (CLD, n=34).

RESULTS

Acetaminophen-induced ALF patients undergoing LT had a greater severity of pre-LT illness reflected by higher Acute Physiology and Chronic Health Evaluation II scores and requirement for organ support compared with the other two groups. Twenty (56%) acetaminophen-induced ALF patients had a formal psychiatric diagnosis before LT (non-acetaminophen-induced ALF=0/35, CLD=2/34; P<0.01 for all) and nine (25%) had a previous suicide attempt. During follow-up (median 5 years), there were no significant differences in rejection (acute and chronic), graft failure or survival between the groups (acetaminophen-induced ALF 1 year 87%, 5 years 75%; non-acetaminophen-induced ALF 88%, 78%; CLD 93%, 82%: P>0.6 log rank). Two acetaminophen-induced ALF patients reattempted suicide post-LT (one died 8 years post-LT).

CONCLUSIONS

Despite a high prevalence of psychiatric disturbance, outcomes for patients transplanted emergently for acetaminophen-induced ALF were comparable to those transplanted for non-acetaminophen-induced ALF and electively for CLD. Multidisciplinary approaches with long-term psychiatric follow-up may contribute to low post-transplant suicide rates seen and low rates of graft loss because of non-compliance.

Curcumin protects rats against acetaminophen-induced hepatorenal damages and shows synergistic activity with N-acetyl cysteine

Acetaminophen is one of the most popular analgesic and antipyretic drugs and its overdose, which can cause severe damage to liver and kidneys, is one of the most common reasons of emergency admissions. In this study we investigated the effects of curcumin, derived from plant Curcuma longa, on acetaminophen toxicity, and the possibility of combining therapy of curcumin and N-acetyl cysteine (NAC) to treat this toxicity. The experiments were conducted on 72 male Sprague-Dawley rats randomly divided into 12 groups. Control group was left without treatment, and the other groups were treated with different combinations of acetaminophen, curcumin and NAC. 15min after intraperitoneal injection, the blood level of curcumin was measured using HPLC. Blood levels of AST (aspartate aminotransferase), ALT (alanine aminotransferase), blood urea nitrogen and creatinine were determined 18 and 42h after acetaminophen injection. One week later, the left kidney and the caudate lobe of the liver were harvested to assay glutathione peroxidase, catalase and malondialdehyde. The right kidney and the remaining lobes of the liver were used for histopathology. Analysis of organ function and oxidation parameters showed that curcumin significantly reduced toxic effects of acetaminophen on the liver and kidneys in a dose-dependent manner and significantly potentiated the protective effects of NAC. These findings were confirmed by histopathology. It is concluded that curcumin can protect the liver and kidney from the damage caused by acetaminophen overdose. Moreover, curcumin has the potential to be used in a combination therapy with NAC, significantly decreasing the therapeutic dose of NAC and therefore its side-effects.

Acetaminophen-induced acute liver failure treated with single-pass albumin dialysis: report of a case

BACKGROUND

Acetaminophen (paracetamol) overdose is a leading cause of acute liver failure (ALF). When patients fulfill the King's College criteria for acetaminophen-induced ALF (AALF), they have a poor prognosis for survival without liver transplantation. Recent advances in artificial liver support have used albumin as a binding and scavenging molecule in ALF. One method, single-pass albumin dialysis (SPAD), involves dialyzing blood against an albumin-containing solution across a high-flux membrane to remove albumin-bound toxins. Herein, we describe our protocol for SPAD and report its use in a case of AALF as a bridge to native liver recovery.

CASE

A 41-year-old female with no documented history of liver disease presented with acute acetaminophen toxicity and developed hepatic encephalopathy, coagulopathy and lactic acidosis. The patient met King's College criteria for liver transplantation, based on pH and INR, but was deemed not suitable as a candidate due to psychosocial comorbidities. On day 3 of her ICU admission, she received the first of five consecutive daily runs (total ~77 hours) of SPAD. The patient's course was complicated by cerebral edema requiring mannitol. She was extubated on day 11 and transferred to the ward by day 13. At ICU discharge, her liver function (INR 1.9, bilirubin 435 mmol/L) and kidney function were recovering. She did not have any long-term neurological sequelae. By hospital discharge (day 46) her native liver function had recovered with a bilirubin <100mmol/L.

CONCLUSION

We describe a case of a patient with acetaminophen-induced acute liver failure who was successfully bridged to spontaneous native liver recovery as a result of SPAD treatment. In patients with ALF, SPAD may be an additional intervention for temporary extracorporeal support. Further investigation in larger prospective studies is warranted.

Acute poisoning: understanding 90% of cases in a nutshell

The acutely poisoned patient remains a common problem facing doctors working in acute medicine in the United Kingdom and worldwide. This review examines the initial management of the acutely poisoned patient. Aspects of general management are reviewed including immediate interventions, investigations, gastrointestinal decontamination techniques, use of antidotes, methods to increase poison elimination, and psychological assessment. More common and serious poisonings caused by paracetamol, salicylates, opioids, tricyclic antidepressants, selective serotonin reuptake inhibitors, benzodiazepines, non-steroidal anti-inflammatory drugs, and cocaine are discussed in detail. Specific aspects of common paediatric poisonings are reviewed.

Dose- and time-dependent oval cell reaction in acetaminophen-induced murine liver injury

We examined the response of murine oval cells, that is, the putative liver progenitor cells, to acetaminophen. Female C57BL/6J mice were injected intraperitoneally with varying doses of N-acetyl-paraaminophen (APAP) (250, 500, 750, and 1,000 mg/kg of weight) and sacrificed at 3, 6, 9, 24, and 48 hours. In preliminary studies, we showed that anticytokeratin antibodies detected A6-positive cells with a sensitivity and specificity of greater than 99%. The oval cell reaction was quantified, on immunostaining for biliary-type cytokeratins, as both number and density of oval cells per portal tract, analyzed by size of portal tract. Acetaminophen injury was followed by periportal oval cell accumulation displaying a moderate degree of morphological homogeneity. Oval cell response was biphasic, not temporally correlating with the single wave of injury seen histologically. Increases in oval cells were largely confined to the smallest portal tracts, in keeping with their primary derivation from the canals of Hering, and increased in a dose-dependent fashion. The timing of the two peaks of the oval cell reaction also changed with increasing dose, the first becoming earlier and the second later. In conclusion, our studies indicate a marked oval cell activation during the height of hepatic injury. Oval cells appear to be resistant to acetaminophen injury. The close fidelity of mechanism and histology of acetaminophen injury between mouse and human livers makes it a useful model for investigating liver regeneration and the participation of stem/progenitor cells in that process.

The effects of a complex homeopathic medicine compared with acetaminophen in the symptomatic treatment of acute febrile infections in children: An observational study

CONTEXT

Children frequently suffer infections accompanied by fever, which is commonly treated with acetaminophen (paracetamol), a use not devoid of risk.

OBJECTIVE

The effect of a complex homeopathic medicine (Viburcol, Heel Belgium, Gent, Belgium) was compared with that of acetaminophen in children with infectious fever.

DESIGN

Non-randomized observational study.

SETTING

Thirty-eight Belgian centers practicing homeopathy and conventional medicine.

PATIENTS

Children <12 years old.

INTERVENTIONS

Viburcol (drops) or acetaminophen (pills, capsules, or liquid form) for a maximum of 2 weeks.

MAIN OUTCOME MEASURES

Fever, cramps, distress, disturbed sleep, crying, and difficulties with eating or drinking. Symptoms were graded by the practitioner on a scale from 0 to 3. Severity of infection was evaluated on a scale from 0 to 4. Data were captured on body temperature, subjective impression of health status, time to first improvement of symptoms, and global evaluation of treatment effects. Tolerability and compliance were monitored.

RESULTS

Both treatment groups improved during the treatment period. Body temperature was reduced by 1.7 degrees C +/- 0.7 degrees C with Viburcol and by 1.9 degrees C +/- 0.9 degrees C with acetaminophen; fever score (scale from 0 to 3) from 1.7 +/- 0.6 to 0.1 +/- 0.2 with Viburcol and from 1.9 +/- 0.7 to 0.2 +/- 0.5 with acetaminophen (all values mean +/-SD). The overall severity of infection (scale from 0 to 4) decreased from 2.0 +/- 0.5 to 0.0 +/- 0.2 with Viburcol and from 2.2 +/- 0.7 to 0.2 +/- 0.6 with acetaminophen. There were no statistically significant differences between treatment groups in time to symptomatic improvement. Viburcol was noninferior to acetaminophen on all variables evaluated. Both treatments were very well tolerated, but the Viburcol group had a significantly greater number of patients with the highest tolerability score.

CONCLUSIONS

In this patient population, Viburcol was an effective alternative to acetaminophen treatment and significantly better tolerated.

Activation of hepatic Nrf2 in vivo by acetaminophen in CD-1 mice

The transcription factor NF-E2-related factor 2 (Nrf2) plays an essential role in the mammalian response to chemical and oxidative stress through induction of hepatic phase II detoxification enzymes and regulation of glutathione (GSH). Enhanced liver damage in Nrf2-deficient mice treated with acetaminophen suggests a critical role for Nrf2; however, direct evidence for Nrf2 activation following acetaminophen exposure was previously lacking. We show that acetaminophen can initiate nuclear translocation of Nrf2 in vivo, with maximum levels reached after 1 hour, in a dose dependent manner, at doses below those causing overt liver damage. Furthermore, Nrf2 was shown to be functionally active, as assessed by the induction of epoxide hydrolase, heme oxygenase-1, and glutamate cysteine ligase gene expression. Increased nuclear Nrf2 was found to be associated with depletion of hepatic GSH. Activation of Nrf2 is considered to involve dissociation from a cytoplasmic inhibitor, Kelch-like ECH-associated protein 1 (Keap1), through a redox-sensitive mechanism involving either GSH depletion or direct chemical interaction through Michael addition. To investigate acetaminophen-induced Nrf2 activation we compared the actions of 2 other GSH depleters, diethyl maleate (DEM) and buthionine sulphoximine (BSO), only 1 of which (DEM) can function as a Michael acceptor. For each compound, greater than 60% depletion of GSH was achieved; however, in the case of BSO, this depletion did not cause nuclear translocation of Nrf2. In conclusion, GSH depletion alone is insufficient for Nrf2 activation: a more direct interaction is required, possibly involving chemical modification of Nrf2 or Keap1, which is facilitated by the prior loss of GSH.

Acetylcysteine treatment for non-acetaminophen-induced acute liver failure

OBJECTIVE

To evaluate the effectiveness of intravenous acetylcysteine in the treatment of non-acetaminophen-induced acute liver failure (ALF).

DATA SOURCES

A search of MEDLINE (1966-March 2003), International Pharmaceutical Abstracts (1970-2003), and Cochrane Library (2003, issue 3) databases was conducted, using the search terms acetylcysteine, non-acetaminophen-induced hepatic failure, liver failure, intravenous, and treatment.

DATA SYNTHESIS

All of the studies found were small and do not provide conclusive evidence that acetylcysteine benefits this subgroup of patients. Microvascular regional benefits were seen, but clinical outcomes have not been studied.

CONCLUSIONS

Intravenous acetylcysteine should not be used routinely for treatment of non-acetaminophen-induced ALF. Further large-scale studies are needed to evaluate clinical outcomes.

The epidemiology of self-poisoning in the UK

Self-poisoning by ingestion or inhalation is common, and it is important to study its various epidemiological manifestations with clear definitions. Data on fatal self-poisonings are recorded nationally within the UK and are codified according to the International Classification of Diseases (ICD) revision relevant at the time. Most fatal self-poisonings are codified as suicides, accidental deaths or undetermined deaths ('open verdicts'). Non-fatal self-poisoning data, whether accidental or as a manifestation of deliberate self-harm, are recorded through hospital discharge information nationally but are not routinely published in the same way as mortality data. The bulk of the UK's published epidemiological information on nonfatal self-poisoning episodes is largely based on individual hospitals' admission or discharge records ('special studies'). After establishing definitions for different self-poisoning categories we discuss the published data on self-poisoning as they relate to suicide, accidental self-poisoning and deliberate self-harm in the UK.

Paracetamol poisoning--impact of pack size restrictions

BACKGROUND

Pack sizes of paracetamol available to the public were reduced by legislation in 1998.

OBJECTIVE

To study the effect of the legislation on paracetamol poisoning related admissions to an accident and emergency department and to a tertiary referral liver unit.

METHOD

Data were obtained from the University Hospitals, Birmingham, UK (UHB) Trust Information Service and the Queen Elizabeth Hospital liver unit records on (a) the number of patients admitted to hospital because of paracetamol overdose and (b) the number of patients admitted to the liver unit with parcetamol-induced hepatotoxicity.

RESULTS

Prior to legislation, an average of 360 people a year were admitted to UHB. However, following the change in legislation the number of admissions has fallen to an average of 250 people per year. This represents a reduction of 31%. Prior to legislation, an average of 76 people per year were admitted to the liver unit. Post-legislation this number has dropped to an average of 38 per year representing a reduction of 50%.

CONCLUSION

Legislation restricting paracetamol pack-size reduced the incidence and severity of poisoning.

Liver death and regeneration in paracetamol toxicity

Paracetamol overdose (POD) is a major clinical problem as the commonest cause of fulminant hepatic failure (FHF) in the UK and the USA. While the main loss of liver mass occurs following hepatocyte necrosis, hepatocyte apoptosis has also been reported to occur during paracetamol toxicity in murine liver. Hepatocyte apoptosis has not previously been identified in human liver and the significance of apoptosis in paracetamol toxicity is not known. In this study of paracetamol toxicity in human liver after POD, hepatocyte apoptosis was identified at time of liver transplantation or death and was associated with striking regenerative activity. The biological significance of apoptosis is unclear but the rates of apoptosis found (0.6%) could account for a significant loss of hepatic parenchyma. The stimulus for apoptosis is not known but it is unlikely to be induced directly by paracetamol since it is absent from serum at this time. The possibility that apoptosis may be induced by Kupffer cell activation with cytokine production is raised. Patients who develop FHF after POD have a poor prognosis, with few therapeutic options apart from liver transplantation; an understanding of the dynamics of liver regeneration and ongoing cell loss by apoptosis may allow the development of new therapies in these patients.

The effect of recalling paracetamol on hospital admissions for poisoning in Western Australia

OBJECTIVES

To assess the effect of two recalls of paracetamol products on rates of intentional and unintentional overdoses of paracetamol in all age groups, as well as any effect on poisoning by other agents.

DESIGN

A before-and-after epidemiological study using data from the Western Australian Health Services Research Linked Database, which records all admissions to public and private hospitals throughout the State.

MAIN OUTCOME MEASURES

Hospital admissions in Western Australia for poisonings with all agents, including paracetamol and other over-the-counter analgesics.

RESULTS

There were 11 752 admissions for poisoning from 1996 to 2001. Paracetamol was the primary poisoning agent in 2266 (19.3%) admissions, aspirin in 120 (1%) and ibuprofen in 277 (2%). There was a significant decrease in the admission rate for paracetamol poisoning when sales were restricted in 2000 (rate ratio, 0.82; 95% CI, 0.68-0.99) compared with the same period in other years. There was no increase in poisoning with other agents at this time. However, admissions for paracetamol overdose also showed a large random variation that tended to obscure any effect.

CONCLUSIONS

Our study highlights the need to control for random as well as seasonal fluctuations in admission rates, and for restrictions on paracetamol sales to last for several months across all retail outlets. Limiting access to paracetamol may reduce paracetamol poisonings without a coincident increase in the use of other agents

Liver and kidney diseases

The spectrum of renal disease in patients with liver disease is expanding. The recognition of renal complications of liver diseases is essential in the management of these patients. As liver transplantation is a treatment option for many patients with chronic liver disease, the presence of renal complications impacts the decision regarding transplantation and influences the course of these patients after transplantation, especially with regard to the use of immunosuppressive therapy. The involvement of the liver and kidney in systemic conditions is common and adds to the morbidity and mortality of patients.

Paracetamol overdose: an evidence based flowchart to guide management

A flowchart for the management of patients with paracetamol poisoning is presented to help clinicians in the emergency department.

Alcohol exposure and paracetamol-induced hepatotoxicity

Most instances of hepatotoxicity due to paracetamol in the United Kingdom and Australia are the result of large overdoses of the drug taken with suicidal or parasuicidal intent. In contrast, serious hepatotoxicity at recommended or near-recommended doses for therapeutic purposes has been reported, mainly from the United States and in association with chronic alcohol use, leading to the widely held belief that chronic alcoholics are predisposed to paracetamol-related toxicity at relatively low doses. Yet the effects of alcohol on paracetamol metabolism are complex. Studies performed in both experimental animals and humans indicate that chronic alcohol use leads to a short-term, two- to threefold increase in hepatic content of cytochrome P4502E1, the major isoform responsible for the generation of the toxic metabolite from paracetamol, although increased oxidative metabolism of paracetamol at recommended doses has not been demonstrated clinically. A reduced hepatic content of glutathione, required to detoxify the reactive metabolite, has been documented in chronic alcoholics, due probably to associated fasting and malnutrition, providing a metabolic basis for any possible predisposition of this group to hepatotoxicity at relatively low paracetamol doses. Simultaneous alcohol and paracetamol ingestion reduces oxidative metabolism of paracetamol in both rodents and humans, predominantly as a consequence of depletion in cytosol of free NADPH. The possibilities that chronic alcohol use may predispose to paracetamol-related hepatotoxicity and that alcohol taken with paracetamol may protect against it, based on these metabolic observations, are examined in this review.

Paracetamol recall: a natural experiment influencing analgesic poisoning

OBJECTIVES

To determine whether the occurrence of paracetamol and non-paracetamol analgesic deliberate self-poisoning (DSP) and accidental paediatric poisoning was affected by two periods of recall of paracetamol products.

DESIGN

Retrospective, observational audit of proportions of poisonings with tablet and capsule formulations of paracetamol, ibuprofen and aspirin products during two recall periods compared with the number of poisonings during the same periods of the previous three years.

SETTING

A national poisons information centre and a regional toxicology service.

MAIN OUTCOME MEASURES

Rates of DSP and accidental paediatric poisoning with paracetamol, ibuprofen and aspirin.

RESULTS

During the two recall periods, there was a significant increase in ibuprofen DSP calls to the poisons information centre (RR, 1.86; 95% Cl, 1.41-2.44; P = 0.001). There was no significant change in paracetamol or aspirin DSP calls over the two recall periods. However, there was a non-significant reduction in DSP calls with paracetamol in the first recall period alone (P = 0.057). There was a significant increase in the proportion of aspirin DSP presentations for the toxicology service (RR, 3.33; 95% CI, 0.97-11.4; P = 0.043), but no significant changes in paracetamol and ibuprofen DSP presentations. For accidental paediatric ingestions there was a significant increase in the proportion of ibuprofen calls (RR, 2.35; 95% CI, 1.85-2.98; P = 0.001), but no significant change in paracetamol or aspirin calls.

CONCLUSIONS

Reduced paracetamol availability increased poisoning with alternative analgesics, but had little effect on the incidence of paracetamol poisoning. Restriction of paracetamol-containing products may inadvertently increase poisoning with potentially more toxic agents.

A NO-releasing derivative of acetaminophen spares the liver by acting at several checkpoints in the Fas pathway

NCX-701 is a nitric oxide (NO)-releasing acetaminophen (APAP) derivative. In the present study we demonstrated that NCX-701 is as effective as APAP in controlling body temperature in a rat model of endotoxin-induced fever. Liver toxicity is a major complication of APAP overdosing. To investigate whether NCX-701 is hepatotoxic, BALB/C mice were injected with 100 - 500 mg kg(-1) APAP or NCX-701 alone or in combination (i.e. 500 mg kg(-1) of both compounds). Our results demonstrated that although APAP caused a dose-dependent liver injury, NCX-701 was completely devoid of liver toxicity. At the dose of 500 mg kg(-1) APAP caused an approximately 40 fold increase of AST plasma levels and extensive centrilobular necrosis. APAP and NCX-701 share the same metabolic pathway as demonstrated by the time-course of APAP-glucuronide concentrations in plasma and liver. NCX-701 was safe in mice with pre-existing chronic liver disease. Indeed, while C57BL6 transgenic mice expressing the hepatitis B virus (HBV) at the age of 8 months were significantly more susceptible to liver damage induced by APAP (500 mg kg(-1)) than their congenic littermates, treating HBV-transgenic mice with NCX-701, 500 mg kg(-1), caused no damage. Co-administration of NCX-701 at the dose 500 mg kg(-1) to mice treated with APAP, 500 mg kg(-1), completely protected against liver damage induced by APAP. APAP, but not NCX-701, upregulated liver Fas and Fas Ligand mRNA expression in vivo. Incubating mouse hepatocytes with APAP, but not with NCX-701, increased cell surface Fas expression and sensitized hepatocytes to death induced by challenge with a Fas-agonistic antibody. Collectively, these observations suggest that APAP toxicity is Fas mediated and that NCX-701 spares the liver by acting at several checkpoints in the Fas pathway.

Role of taurine in preventing acetaminophen-induced hepatic injury in the rat

Acetaminophen overdose causes acute liver injury in both humans and animals. This study was designed to investigate the potential role of the conditionally essential amino acid taurine in preventing acetaminophen-induced hepatotoxicity. Male Sprague-Dawley rats were administered acetaminophen (800 mg/kg) intraperitoneally. Taurine (200 mg/kg) was given 12 h before, at the time of, and 1 or 2 h after acetaminophen injection. Acetaminophen treatment increased the plasma levels of aspartate transaminase, alanine aminotransferase, and alkaline phosphatase and caused hepatic DNA fragmentation and hepatocyte necrosis. Taurine administered before, simultaneously with, or 1 h after acetaminophen resulted in significant improvement in hepatic injury as represented by decrease of hepatocellular enzyme release and attenuation of hepatocyte apoptosis and necrosis, and this correlated with taurine-mediated attenuation of hepatic lipid peroxidation. These results indicate that taurine possesses prophylactic and therapeutic effects in acetaminophen-induced hepatic injury.

Reduction in incidence of severe paracetamol poisoning

We report substantial reductions in the frequency of severe paracetamol hepatotoxicity locally and nationally after legislative limitations on its sale. These reductions were not explained by changes in referral patterns or use of N-acetylcysteine.

Supply of medicines: paternalism, autonomy and reality

Radical changes are taking place in the United Kingdom in relation to the classification of, and access to, medicines. More and more medicines are being made available over the counter both in local pharmacies and in supermarkets. The provision of more open access to medicines may be hailed as a triumph for patient autonomy. This paper examines whether such a claim is real or illusory. It explores the ethical and legal implications of deregulating medicines. Do patients benefit? What is the impact on pharmacists? Are the true beneficiaries of change largely the pharmaceutical industries?

Use and outcome of liver transplantation in acetaminophen-induced acute liver failure

Once defined clinical criteria are fulfilled in acetaminophen-induced hepatotoxicity, prognosis without orthotopic liver transplantation (OLT) may be very poor. In the present study, we examined the application and outcome of OLT in 548 patients admitted to a single center between 1990 and 1996. Four hundred twenty-four (77%) of the patients studied did not fulfill transplantation criteria, and 396 of these (93%) survived. The majority of the 28 nonsurvivors (7%) in this group fulfilled two of three combined criteria, and the finding of a high APACHE III score could be used as an indicator for the need for OLT. Of the 56 patients (45%) not listed, in only a small proportion was this caused by psychiatric reasons, and in the majority, it was a consequence of the rapid development of multiple organ failure and cerebral edema. This also applied to 24 (35%) of the 68 listed patients in whom the rapidity of clinical deterioration, reflected in increasing APACHE III scores, was such that even with the prompt availability of donor organs, OLT was not possible. In the final event, only 44 (35%) of those who fulfilled criteria underwent OLT, of whom 33 (75%) survived to leave the hospital. Survival was greatest in those receiving unreduced grafts, and markers of early graft function differed significantly between survivors and nonsurvivors. Liver transplantation is an effective treatment in a relatively small number of patients with acetaminophen-induced hepatotoxicity, and for a substantial proportion, transplantation was never an option because of the rapidity of clinical deterioration. APACHE III scoring may be of value in decision making and in better defining patients in clinical trials.