Acute Acetaminophen Research Articles

Acute acetaminophen ingestion improves the recovery of neuromuscular fatigue following simulated soccer match-play

ObjectiveThis study aimed to investigate the impact of acute acetaminophen (ACT) ingestion on the responses of neuromuscular function, biomarkers of muscle damage, and physical performance during the 72-h recovery period following simulated soccer match-play. DesignThe study followed a crossover randomized, double-blind, placebo-controlled trial design. MethodsDuring the two experimental sessions, thirteen semi-professional male soccer players completed a 90-min simulated soccer match, 60 min after oral ingestion of 1 g ACT or placebo (PL). Maximal voluntary contraction (MVC) and twitch responses of the knee extensors muscles, elicited through electrical femoral nerve stimulation, were utilized to evaluate both peripheral fatigue (potentiated twitch force, Qtw,pot) and central fatigue (voluntary activation, VA). Performance was assessed through countermovement jump (CMJ) and 20 m sprint tests. Creatine kinase (CK) and lactate dehydrogenase (LDH) were also measured. ResultsSmaller reductions were observed in MVC (−13.3 ± 7.5 % vs. -24.7 ± 11.1 %) and VA (−3.8 ± 4.4 % vs. -12.9 ± 5.4 %) in the ACT compared to the PL condition immediately after simulated soccer match-play (p < 0.05). Afterwards, these parameters were recovered 24 h earlier in the ACT session compared to the PL session. Furthermore, the 20 m sprint performance was significantly better throughout the recovery period in the ACT session compared to the PL session. ConclusionThe findings of this study showed that acute ingestion of 1 g of ACT (1 h before exercise) attenuated the decrease in MVC and VA levels after exercise, as well as improved 20 m sprint performance.

Patterns of acetaminophen toxicity among patients with low-risk serum concentrations.

In 2012, the Commission on Human Medicines mandated lowering the acetaminophen toxicity nomogram treatment threshold in the UK to 100 µg/ml at 4 h post-ingestion. The present study aim was to evaluate biochemical and liver toxicity patterns in patients who presented with acetaminophen overdose and had low serum acetaminophen concentrations (<150 µg/ml). Patients admitted to the emergency department with a clear history of acute acetaminophen overdose with or without other medication or ethanol were consecutively enrolled into this retrospective cohort study. Patients with serum acetaminophen concentration >150 µg/ml or an unknown ingestion time were excluded. Data were extracted from electronic medical records and are presented as mean ± SD or median (interquartile range). A total of 103 patients were included (median age, 17 [4-21] years) and 80 (78%) were female. The median ingested acetaminophen dose was 5000 (2850-7650) mg. At baseline, the median serum acetaminophen concentration was 42 (4.5-64.8) µg/ml, and median alanine aminotransferase and aspartate aminotransferase levels were 22 (17-28) and 27 (16-45) IU/L, respectively. Twenty patients were treated with acetylcysteine, with none developing adverse reactions. No patient developed hepatotoxicity, including patients with initial multiple product ingestion or other risk factors. Patients presenting with an acute acetaminophen overdose with acetaminophen level <150 µg/ml, including patients with other risk factors, are at low risk of hepatotoxicity.

Acute ingestion of acetaminophen improves cognitive and repeated high intensity short-term maximal performance in well-trained female athletes: a randomized placebo-controlled trial

This study examined the effect of acute acetaminophen (ACTP) ingestion on physical performance during the 5 m shuttle run test (5mSRT), attention, mood states, and the perception of perceived exertion (RPE), pain (PP), recovery (PRS), and delayed onset of muscle soreness (DOMS) in well-trained female athletes. In a randomized, placebo-controlled, double-blind, crossover trial, fifteen well-trained female athletes (age 21 ± 2 years, height 165 ± 6 cm, body mass 62 ± 5 kg) swallowed either 1.5 g of ACTP or 1.5 g of placebo. The profile of mood states (POMS) and digit cancellation (DCT) were assessed 45 min postingestion, and 5mSRT was performed 60 min postingestion. The RPE and PP were determined immediately after each 30-s repetition of the 5mSRT, and the PRS and DOMS were recorded at 5 min and 24 h post-5mSRT. For the 5mSRT, ACTP ingestion improved the greatest distance (+ 10.88%, p < 0.001), total distance (+ 11.33%, p = 0.0007) and fatigue index (+ 21.43%, p = 0.0003) compared to PLA. Likewise, the DCT score was better on the ACTP (p = 0.0007) than on the PLA. RPE, PP, PRS, and DOMS scores were improved after ACTP ingestion (p < 0.01 for all comparisons) compared to PLA. POMS scores were enhanced with ACTP ingestion compared to PLA (p < 0.01). In conclusion, this study indicates that acute acetaminophen ingestion can improve repeated high intensity short-term maximal performance, attention, mood states, and perceptions of exertion, pain, recovery, and muscle soreness in well-trained female athletes, suggesting potential benefits for their overall athletic performance and mood state.

Two versus Three Infusion Regimens of N-Acetylcysteine for Acetaminophen Overdose.

Acetaminophen overdose is a common clinical condition, often leading to liver toxicity. Current treatments involve the three-infusion N-Acetylcysteine (NAC) regimen (FDA-labeled), which may be complex, time-consuming, and need to be changed. An alternative uses two infusions instead, which offers possible advantages regarding simplicity and administration errors. This study sought to compare the respective efficacies and safety outcomes when treating acute acetaminophen overdose among children and adolescents. At Montreal Children's Hospital, a retrospective study was conducted comparing pre-2003 FDA-labelled three-infusion NAC therapy with a two-infusion regimen. Information was collected regarding patient demographics, NAC administration details, errors, rates of hepatotoxicity, and adverse reactions, and the statistical test Chi-square test was employed to obtain the results. A total of 126 patients met the inclusion criteria. Of these patients, 65 received a two-infusion regimen, and 61 patients received the FDA-labeled regimen. The two-infusion group experienced significantly fewer administration errors (4 errors vs. 23 errors; p < 0.001), while the rates of hepatotoxicity between them were similar. There were no instances of liver transplantation or mortality due to either regimen. Adverse reactions occurred equally frequently between both regimens with no discernible difference-the meantime to administer NAC was 9 h for the two-infusion regimen and 8.5 h for FDA-labeled regimen groups, respectively. Three cases of hepatitis were successfully treated with timely NAC therapy, and no liver transplantation or mortality occurred. Adverse reactions, including anaphylactoid reactions, were observed in both groups but were resolved when temporarily stopped and restarted at a slower infusion rate. The two-infusion NAC regimen proved similar efficacy at protecting liver damage and improving patient outcomes compared to its FDA-labeled three-stage counterpart, with significantly fewer administration errors for this version of NAC treatment, suggesting potential advantages in terms of safety and simplicity. Future research should investigate larger cohorts and more variables to validate these results further and optimize the management of acetaminophen overdose cases; further investigation should focus on dosing strategies, personalized approaches, and long-term patient care in this context.

Predicting serum acetaminophen concentrations in acute poisoning for safe termination of N-acetylcysteine in a resource-limited environment

Purpose: The Prescott nomogram has been utilized to forecast hepatotoxicity from acute acetaminophen poisoning. In developing countries, emergency medical centers lack the resources to report acetaminophen concentrations; thus, the commencement and cessation of treatment are based on the reported dose. This study investigated risk factors that can predict acetaminophen detection after 15 hours for safe treatment termination.Methods: Data were collected from an urban emergency medical center from 2010 to 2020. The study included patients ≥14 years of age with acute acetaminophen poisoning within 15 hours. The correlation between risk factors and detection of acetaminophen 15 hours after ingestion was evaluated using logistic regression, and the area under the curve (AUC) was calculated.Results: In total, 181 patients were included in the primary analysis; the median dose was 150.9 mg/kg and 35 patients (19.3%) had acetaminophen detected 15 hours after ingestion. The dose per weight and the time to visit were significant predictors for acetaminophen detection after 15 hours (odds ratio, 1.020 and 1.030, respectively). The AUCs were 0.628 for a 135 mg/kg cut-off value and 0.658 for a cut-off 450 minutes, and that of the combined model was 0.714 (sensitivity: 45.7%, specificity: 91.8%).Conclusion: Where acetaminophen concentrations are not reported during treatment following the UK guidelines, it is safe to start N-acetylcysteine immediately for patients who are ≥14 years old, visit within 15 hours after acute poisoning, and report having ingested ≥135 mg/kg. Additional N-acetylcysteine doses should be considered for patients visiting after 8 hours.

Assessing Platelet Mitochondrial Dysfunction in a Murine Model of Acute Acetaminophen Toxicity.

Acetaminophen (APAP) toxicity remains a significant cause of adult and pediatric liver failure in North America and Europe. Previous research has evaluated the impaired mitochondrial function associated with APAP toxicity. The primary aim of this study was to evaluate the effects of APAP toxicity on platelet mitochondrial function using platelet oxygen consumption in a murine model in vivo. Our secondary objectives were to determine the effect of 4-MP on platelet mitochondrial function and hepatic toxicity in the setting of APAP overdose, and to correlate platelet mitochondrial function with other markers of APAP toxicity. Male C57Bl/6 mice were randomized to receive APAP (300 or 500mg/kg) or vehicle followed 90minutes later by either 4-MP (50mg/kg) or vehicle via intraperitoneal injection. Mice were euthanized 0, 12, or 24hours later and platelets isolated from cardiac blood and counted. Platelet oxygen consumption (POC) was determined using a closed-system respirometer. Liver injury was assessed by measuring alanine transferase (ALT) and histological evaluation. Injection of 500mg/kg APAP led to increased POC versus pair-matched control (vehicle) (p < 0.001). Administration of 4-MP did not affect POC in control or 300mg/kg APAP mice. In mice receiving 500mg/kg APAP and 4-MP, POC decreased significantly compared to mice receiving 500mg/kg APAP alone (p < 0.01). Serum and histological analysis confirmed APAP-induced hepatic damage in mice receiving 500mg/kg APAP and these effects blunted by treatment with 4-MP. Platelet oxygen consumption as a measure of mitochondrial function may be useful as a biomarker of hepatic APAP toxicity in the setting of moderate to severe overdose. Treatment with 4-MP decreases hepatic necrosis and may mitigate the harmful effects of APAP on platelet mitochondrial function detected via POC.

Biofabricated Palladium Nanoparticle-Decorated Reduced Graphene Oxide Nanocomposite Using the Punica granatum (Pomegranate) Peel Extract: Investigation of Potent In Vivo Hepatoprotective Activity against Acetaminophen-Induced Liver Injury in Wistar Albino Rats.

Acute acetaminophen (APAP) toxicity is a predominant clinical problem, which causes serious liver injury in both humans and experimental animals. This study presents the histological and biochemical factor and antioxidant enzyme level changes induced by an acute acetaminophen overdose in Wistar albino rat livers to elucidate the effective hepatoprotective potential of biofabricated palladium nanoparticle-decorated reduced graphene oxide nanocomposites (rGO/PdNPs-NC) compared to silymarin. After detailed characterization of the hepatoprotective potential of the synthesized rGO/PdNPs-NC, the rats were divided into eight groups (n = 6): control group (normal saline, 1 mL/kg b.w.), silymarin, Punica granatum (pomegranate) peel extract, PdNPs, reduced graphene oxide (rGO-PG), and reduced graphene oxide palladium nanocomposites (rGO/PdNPs-NC, low and high doses) for 7 successive days. The acetaminophen (APAP)-treated group was administered a single dose of acetaminophen (2 g/kg b.w.) on the 8th day. The histopathological results showed that the acetaminophen overdose group exhibited massive intrahepatic hemorrhagic necrosis around the centrilobular region with hepatocytes with vacuolization and swollen cytoplasm found in the liver architecture. This hepatopotential was further assessed by various biochemical parameters such as SGOT, SGPT, ALB, ALP, LDH, direct bilirubin, total bilirubin, and total protein. Also, the antioxidant parameters such as SOD, CAT, MDA, GSH, GRD, and GST were assayed. Rats of groups 7 and 8 showed a significant decrease in SGOT, SGPT, ALP, LDH, direct bilirubin, and total bilirubin (p < 0.001), while a significant increase in the final total protein and ALB as compared to group 2 rats (p < 0.001) was observed. The antioxidant parameters exhibited that rats of groups 7 and 8 showed a significant (p < 0.001) increase in the level of SOD, CAT, GSH, GRD, and GST without affecting the MDA as compared to group 2 rats. Also, the hepatoprotective potential of rGO/PdNPs-NC (low and high doses) was comparable to that of the standard reference drug silymarin. The present study reveals that the rGO/PdNPs-NC possesses significant hepatoprotective activity and acts as an effective and promising curative agent against acetaminophen-induced hepatotoxicity.

Using a decision tree algorithm to distinguish between repeated supra-therapeutic and acute acetaminophen exposures

BackgroundThis study aimed to compare clinical and laboratory characteristics of supra-therapeutic (RSTI) and acute acetaminophen exposures using a predictive decision tree (DT) algorithm.MethodsWe conducted a retrospective cohort study using the National Poison Data System (NPDS). All patients with RSTI acetaminophen exposure (n = 4,522) between January 2012 and December 2017 were included. Additionally, 4,522 randomly selected acute acetaminophen ingestion cases were included. After that, the DT machine learning algorithm was applied to differentiate acute acetaminophen exposure from supratherapeutic exposures.ResultsThe DT model had accuracy, precision, recall, and F1-scores of 0.75, respectively. Age was the most relevant variable in predicting the type of acetaminophen exposure, whether RSTI or acute. Serum aminotransferase concentrations, abdominal pain, drowsiness/lethargy, and nausea/vomiting were the other most important factors distinguishing between RST and acute acetaminophen exposure.ConclusionDT models can potentially aid in distinguishing between acute and RSTI of acetaminophen. Further validation is needed to assess the clinical utility of this model.

Essential Involvement of Neutrophil Elastase in Acute Acetaminophen Hepatotoxicity Using BALB/c Mice.

Intense neutrophil infiltration into the liver is a characteristic of acetaminophen-induced acute liver injury. Neutrophil elastase is released by neutrophils during inflammation. To elucidate the involvement of neutrophil elastase in acetaminophen-induced liver injury, we investigated the efficacy of a potent and specific neutrophil elastase inhibitor, sivelestat, in mice with acetaminophen-induced acute liver injury. Intraperitoneal administration of 750 mg/kg of acetaminophen caused severe liver damage, such as elevated serum transaminase levels, centrilobular hepatic necrosis, and neutrophil infiltration, with approximately 50% mortality in BALB/c mice within 48 h of administration. However, in mice treated with sivelestat 30 min after the acetaminophen challenge, all mice survived, with reduced serum transaminase elevation and diminished hepatic necrosis. In addition, mice treated with sivelestat had reduced NOS-II expression and hepatic neutrophil infiltration after the acetaminophen challenge. Furthermore, treatment with sivelestat at 3 h after the acetaminophen challenge significantly improved survival. These findings indicate a new clinical application for sivelestat in the treatment of acetaminophen-induced liver failure through mechanisms involving the regulation of neutrophil migration and NO production.

383 What Aminotransferase Values Are Clinically Important After Acetaminophen Poisoning?

Acute acetaminophen ingestion management includes plotting an acetaminophen concentration on the population-based Rumack-Matthew Nomogram. Nomogram implementation reflects an estimate of probability of hepatotoxicity (defined as aspartate or alanine aminotransferase >1,000 IU/L) based on ingestion time and acetaminophen concentration. Similarly, patients with unknown or repeated supratherapeutic acetaminophen exposure are treated with acetylcysteine to mitigate liver injury. Antidote efficacy is time sensitive, however, once hepatotoxicity is identified patients often have extended hospital courses and acetylcysteine administration.

Characterization and Quantification of Oxidized High Mobility Group Box 1 Proteoforms Secreted from Hepatocytes by Toxic Levels of Acetaminophen.

The high mobility group box 1 (HMGB1), which is released during acute acetaminophen (APAP) overdose, is thought to mediate a subsequent immune response, particularly hepatic infiltration of macrophages. The redox behavior of HMGB1 and the proteoforms of HMGB1 present in oxidative environments has been the subject of a number of confusing and contradictory studies. Therefore, a stable isotope dilution two-dimensional nanoultrahigh-performance liquid chromatography parallel reaction monitoring/high-resolution mass spectrometry method was developed in order to characterize and quantify oxidative modifications to the cysteine (Cys) residues (Cys-23, Cys-45, and Cys-106) that are present in HMGB1. Disulfide linkages were determined using carbamidoethyl derivatization before and after reduction as well as by direct analysis of disulfide cross-linked peptides. A stable isotope labeled form of HMGB1 was used as an internal standard to correct for sample to sample differences in immunoaffinity precipitation, derivatization, and electrospray ionization. Four discrete HMGB1 proteoforms were found to be released from a hepatocarcinoma cell model of APAP overdose after 24 h. Fully reduced HMGB1 with all three Cys-residues in their free thiol state accounted for 18% of the secreted HMGB1. The proteoform with disulfide between Cys-23 and Cys-45 accounted for 24% of the HMGB1. No evidence was obtained for a disulfide cross-link between Cys-106 and the other two Cys-residues. However, 45% of the HMGB1 formed a cross-link with unidentified intracellular proteins via an intermolecular disulfide bond, and 12% was present as the terminally oxidized cysteic acid. Surprisingly, there was no evidence for the formation of HMGB1 disulfides with GSH or other low molecular weight thiols. Secreted plasma HMGB1 Cys-23/Cys45 disulfide proteoform together with the Cys-106/protein disulfide proteoforms could potentially serve as early biomarkers of hepatoxicity after APAP overdose as well as biomarkers of drug-induced liver injury.

Evaluating the hepatoprotective, ameliorative and antioxidant potentials of the crude aqueous leafy extracts of Mangifera indica plant against acute paracetamol-induced hepatotoxicity in amouse model.

Background:Drug-induced hepatotoxicity is a major public health issue of concern. It significantly affects the development of new pharmaceutical drugs and has led to the withdrawal of many promising pharmaceutical drugs from the pharmaceutical market.Aim:The aim of this study was to evaluate the hepatoprotective, ameliorative and antioxidant effects of the crude aqueous leafy extract of Mangifera indica plant and its different separating medium fractions against acute acetaminophen (paracetamol)-induced hepatotoxicity in a mouse model.Methods & materials:Twelve different groups of six mice (three males and three females) were used for this study. Acetaminophen at a single lethal hepatotoxic dose of 3 g/kg was orally administered on the seventh day to the mice in groups 2 to 12 after their 6-day pretreatment duration for the induction of hepatotoxicity; and were then left for 24 hours before the collection of specimen samples were completed, while group 1 served as control.Results:The crude aqueous leafy extract of M. indica (125-250 mg/kg) produced a dose-dependent reversal of the lethal hepatotoxic effect of oral 3 g/kg dose of paracetamol. At the dose of 250 mg/kg, it significantly (p < 0.0001) reduced the levels of hepatic enzymes markers (alanine transaminase [ALT], aspartate transaminase [AST] and alkaline phosphatase [ALP]) in the serum of treated animals. Also, the effects of the crude aqueous leafy extract were found to be statistically significant (p < 0.0001) more than that of its different separating medium fractional components.Conclusion:The findings from this study demonstrated that the crude aqueous leafy extract of M. indica possesses hepatoprotective effect, possibly mediated through the induction of antioxidant enzymes to prevent the occurrence of oxidative stress damage or most likely through the inhibition of pro-inflammatory mediators which are being induced by the lethal hepatotoxic dose of paracetamol.

The spatiotemporal program of zonal liver regeneration following acute injury

The liver carries a remarkable ability to regenerate rapidly after acute zonal damage. Single-cell approaches are necessary to study this process, given the spatial heterogeneity of liver cell types. Here, we use spatially resolved single-cell RNA sequencing (scRNA-seq) to study the dynamics of mouse liver regeneration after acute acetaminophen (APAP) intoxication. We find that hepatocytes proliferate throughout the liver lobule, creating the mitotic pressure required to repopulate the necrotic pericentral zone rapidly. A subset of hepatocytes located at the regenerating front transiently upregulate fetal-specific genes, including Afp and Cdh17, as they reprogram to a pericentral state. Zonated endothelial, hepatic stellate cell (HSC), and macrophage populations are differentially involved in immune recruitment, proliferation, and matrix remodeling. We observe massive transient infiltration of myeloid cells, yet stability of lymphoid cell abundance, in accordance with a global decline in antigen presentation. Our study provides a resource for understanding the coordinated programs of zonal liver regeneration.

Sensitivity of dose-estimations for acute acetaminophen overdose in predicting hepatotoxicity risk using the Rumack-Matthew Nomogram.

Timely assessment of acetaminophen concentration in overdose situations is not always available in resource‐poor settings. The 150 mg/kg dose‐estimate for acetaminophen is widely considered as criterion for acetaminophen overdose. Its sensitivity and specificity when compared to the 150 mg/L treatment line on the Rumack‐Matthew Nomogram (150‐treatment line) has rarely been evaluated. This is a retrospective chart review of acute acetaminophen overdose patients. We evaluated the sensitivity and specificity of the 150, 200 mg/kg and 8‐ and 10‐g dose‐estimates by plotting the serum acetaminophen levels and using 150‐treatment line on the Nomogram as the treatment cut‐off. A comparison of medical care costs was performed. We enrolled 784 cases for analysis. Median (IQR) age was 23 (20–28) years (81.9% female). There were 545 cases (69.5%) where the estimated ingested acetaminophen dose were ≥150 mg/kg and 406 cases (51.8%) with concentrations ≥150‐treatment line. Hepatotoxicity and acute liver injury (ALI) occurred in 7.3% and 23.9%, respectively. The sensitivity and specificity of 150 mg/kg dose‐estimate for the 150‐treatment line were 92.6% (95% CI 89.6, 94.8) and 55.3% (95% CI 50.3, 60.2). Among patients with dose‐estimate below150 mg/kg, none developed hepatotoxicity and 17 (7.1%) develop ALI. The administration of activated charcoal significantly decreased the risk of being above the 150‐treatment line by half. In resource‐poor setings, the use of 150 mg/kg dose‐estimate as a stand‐alone criteria for initiation of N‐acetylcysteine therapy is satisfactory, especially when combined with decontamination with activated charcoal and follow up of aminotransferase at 24 h.

Macrophage migration inhibitory factor as a potential biomarker in acetaminophen overdose: a pilot study

Acetaminophen overdose is a leading cause of liver failure in the United States. Macrophage migration inhibitory factor (MIF) is a cytokine that is released early and promotes acetaminophen toxicity in preclinical models. This cytokine could prove a useful biomarker in emergency department (ED) patients immediately following an acute acetaminophen overdose. We selected a convenience sample of thirteen patients from a prospective consecutive cohort of ED patients with suspected acute overdose. Research associates collected waste specimens for MIF analysis that remained after use for clinical care. Our team compared patients with confirmed acetaminophen overdose (n = 9) to patients without acetaminophen exposure or liver injury (n = 3) and a patient with liver injury in the absence of detectable acetaminophen (n = 1). In our acetaminophen group, all nine patients had measurable acetaminophen concentrations. Median MIF serum concentrations were 16.08 ng/mL (In this pilot study, MIF was feasible to measure in specimens from an ED drug overdose cohort, and was significantly elevated in the acetaminophen group compared to non-acetaminophen controls without liver injury.

Acetaminophen Intoxication with Fulminant Hepatic Failure Salvaged by Plasmapheresis

Introduction Acetaminophen-induced liver injury is the most common cause of acute liver failure, where multiple ingestions or a delay in the presentation may lead to a poor prognosis. N-acetylcysteine (NAC) is the conventional antidote used to treat acute acetaminophen toxicity, and plasmapheresis can be used as an adjunct, though there are no systematic studies to prove its effectivity. Case Presentation An 18-year-old girl was admitted with reduced responsiveness for one day with a few episodes of diarrhea. On admission, she was febrile and had a GCS of 10/15, otherwise normal neurology. She had marked right hypochodrial tenderness, deep icterus, and a pulse of 120 beats per minute, with a blood pressure of 80/50 mmHg; fluid resuscitation with inotropic support was done. Initial investigations revealed severe metabolic acidosis, hemoglobin of 9.5 g/dL, white blood cell count 13,500/mm3, and platelet 119,000 per µL. The prothrombin time (PT) international normalized ratio (INR) was 4.7, and the activated partial thromboplastin time (APTT) was 38.6. The alanine aminotransferase (ALT) level was 8118 U/L, and aspartate aminotransferase (AST) was 3883 U/L with a total bilirubin of 107 µmol/L. The diagnosis of acute liver failure following acetaminophen intoxication was made and managed with intravenous NAC, pantoprazole cover, intravenous ceftriaxone, metronidazole, thiamine, and vitamin K. Fresh frozen plasma and platelets were given for severe coagulopathy. She was started with plasmapheresis at the intensive care unit (ICU), where she had a significant improvement, though she developed hospital-acquired pneumonia, which was successfully managed. Subsequently, her liver functions returned to the baseline, and she was discharged after a psychiatric assessment. Conclusion A high degree of suspicion needs to be adopted to diagnose acetaminophen-induced acute liver failure when a patient presents with hepatic encephalopathy, and plasmapheresis can be considered a life-saving measure adjunct to the NAC.

Decision tree outcome prediction of acute acetaminophen exposure in the United States: A study of 30,000 cases from the National Poison Data System.

Acetaminophen is one of the most commonly used analgesic drugs in the United States. However, the outcomes of acute acetaminophen overdose might be very serious in some cases. Therefore, prediction of the outcomes of acute acetaminophen exposure is crucial. This study is a 6-year retrospective cohort study using National Poison Data System (NPDS) data. A decision tree algorithm was used to determine the risk predictors of acetaminophen exposure. The decision tree model had an accuracy of 0.839, an accuracy of 0.836, a recall of 0.72, a specificity of 0.86 and an F1_score of 0.76 for the test group and an accuracy of 0.848, a recall of 0.85, a recall of 0.74, a specificity of 0.87 and an F1_score of 0.78 for the training group. Our results showed that elevated serum levels of liver enzymes, other liver function test abnormality, anorexia, acidosis, electrolyte abnormality, increased bilirubin, coagulopathy, abdominal pain, coma, increased anion gap, tachycardia and hypotension were the most important factors in determining the outcome of acute acetaminophen exposure. Therefore, the decision tree model is a reliable approach in determining the prognosis of acetaminophen exposure cases and can be used in an emergency room or during hospitalization.

A Basis for the Decision to Rule in or out Acetaminophen Toxicity: Assessment of the Serum Level Within 4 Hours Post Overdose

Background: Acetaminophen is a popular antipyretic and analgesic medication worldwide; however, its therapeutic window is narrow, which may lead to overdose or toxicity. This study was conducted to assess the correlation between the serum acetaminophen levels before and 4 hours after the acute toxicity with this drug. The objective of this study was to test the validity of the serum level to arrive at a clinical decision on the toxicity with acetaminophen. Methods: This cross-sectional study was performed on patients hospitalized and treated with a diagnosis of acute acetaminophen overdose during one year (Sept. 2018 to Sept. 2019) at the Toxicology Department of Imam Reza Hospital, Mashhad, Iran. Patients were analyzed for demographics, time of ingestion, their first and second serum acetaminophen concentrations. Results: A total of 204 patients (106 male &amp; 98 female) were included in this study. The average dose of acetaminophen ingestion by these patients was 14.5±3.50 g and all patients were treated successfully with N-Acetyl-Cysteine (NAC). The variables of age (P=0.293), serum acetaminophen levels at 1-2 h (P=0.679), and at 2-3 h (P=0.126) did not have significant relationships with the serum acetaminophen level on the fourth hour. However, the serum acetaminophen levels tested between 3-4 h and acetaminophen intoxication dosage had significant relationships with the acetaminophen level on the fourth hour. Conclusion: In patients with acute acetaminophen toxicity, the data on the serum levels obtained before a 4-hour timepoint from the ingestion were not useful to decide on the need for the rescue treatment with N-acetyl-cysteine.

S2694 Severe Acute Liver Failure in a Patient With SARS-CoV-2 Infection

Introduction: Hospitalized patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, are regularly found to have elevated LFTs. Up to 46% had elevated AST and 35% had elevated ALT. Occasional elevations in GGT, ALP, and total bilirubin are also seen. These elevations were usually below 5 times the upper limit of normal (ULN). Less than 10% of patients had severe liver injury (ALT > 5 times ULN). Hepatic injury in COVID-19 can be attributed to numerous causes including direct injury, drug toxicity and inflammatory storm. Direct injury is thought to occur when SARS-CoV-2 binds directly to ACE-2 which are abundantly expressed in biliary and liver epithelial cells. We present the case of an 88-year-old COVID-19 patient with severe liver failure managed conservatively. Case Description/Methods: 88-year-old male with history of CHF, atrial fibrillation on Apixaban, DM-2, HTN and recent diagnosis of COVID-19 presented with shortness of breath. Vitally, he was normotensive but hypoxic. Initial labs are shown in Table 1. He denied an established history of liver disease, alcohol use or hepatotoxic drug use. Chest CTA had findings concerning for COVID-19 pneumonia and acute pulmonary embolism. He was not started on Remdesivir due to elevated LFTs. His acute hepatitis panel and acetaminophen level were negative. The patient’s LFTs continued to worsen over his hospital course (Image 1). Transfer to a tertiary liver center was not considered due to his tenuous condition, age, and comorbidities. On day five the patient’s AST and ALT started trending down. However, total bilirubin continued to rise, and ALP stayed relatively stable. His respiratory status continued to worsen, and he was eventually transitioned to comfort care. Discussion: In the absence of an established history of liver disease, alcohol abuse, or hepatotoxic drug use, we believe that our patient’s acute liver failure might have been a direct complication of COVID-19 infection. Treatment with 1-2 drugs from the following categories: hepatoprotective, anti-inflammatory, and jaundice-reducing agents including polyene phosphatidyl choline, glycyrrhizic acid, bicyclol, and vitamin E has been proposed to reduce the burden of liver injury. With the increasing number of cases of liver injury with COVID-19, it is pivotal to identify its pathogenesis, acute interventions, and potential long-term complication to treat this life-threatening condition promptly and effectively.Table 1.: demonstrating our patient’s initial labs.Figure 1.: Image 1 demonstrating lab trend of our patient over his hospital stay.

Evaluation of N-acetylcysteine dose for the treatment of massive acetaminophen ingestion

Methods The use of N-acetylcysteine (NAC) remains the standard of care for treatment of acetaminophen (APAP) toxicity and overdose. Currently, there is growing evidence to suggest that massive acetaminophen overdose is associated with increased hepatotoxicity despite timely administration of NAC. This raises the question as to whether an increased dose of intravenous (IV) NAC should be used in the setting of massive APAP ingestion. This study aimed to evaluate the rate of hepatotoxicity after massive APAP overdose treated with 3 different NAC treatment regimens. Methods This was a retrospective cohort study conducted by electronic medical record review of cases reported to a statewide poison control system between 2007 and 2020. Inclusion criteria were single APAP or APAP combination-medication ingestion; acute massive acetaminophen (APAP) ingestion (defined as APAP concentration ≥ 2 times above the Rumack-Matthew 150 nomogram); received one of the three NAC regimens: standard dose IV NAC, oral (PO) NAC, or high dose IV NAC. The risk of hepatotoxicity was evaluated using a multivariate logistic regression model with standard dose IV NAC as the base variable for comparison. Results A total of 373 patients met inclusion for the study. Of those, 135 cases were treated with standard dose IV NAC, 121 cases treated with PO NAC, and 117 cases treated with high dose IV NAC. The risk of developing hepatotoxicity was not statistically significant between the high dose IV NAC (OR 1.05, 95% CI 0.52 − 2.09) or oral NAC (OR 0.69, 95% CI 0.33 − 1.46) when compared to standard dose IV NAC. When adjusted for APAP combination medications, initial APAP ratio, initial elevated AST/ALT, and treatment within 8 h, there remained no difference between treatment regimens. Conclusion This study was unable to detect a large absolute reduction in the rate of hepatotoxicity after massive APAP ingestion in patients treated with high dose IV NAC or PO NAC when compared to standard dose IV NAC; even when treatment was initiated within 8 h of ingestion.