Clinical policy: critical issues in the management of patients presenting to the emergency department with acetaminophen overdose

Protective action of ultrasound-guided electrolysis technique on the muscle damage induced by notexin in rats

It is known that exercise can be one of the causes of muscular damage. In recent times, physiotherapists and medical professionals have been employing USGET techniques to stimulate muscle recovery to improve its performance after the injury. We pretend to analyse if the Ultrasound-guided electrolysis (USGET) technique could reduce muscle damage, inflammation, and pain in the present study. Female Wistar rats were assigned to one of three different groups: control (C), notexin (NOT) and notexin with USGET (electrolysis at 6mA) (NOT+USGET). We used the USGT technique, based on electrical stimulation with a continuous current of 4 pulses at an intensity of 6 mA for 5 seconds, conveyed to the muscle. The response was tested with motor function tests. In these tests, we could observe an increase in time and foot faults when crossing a beam in the NOT group compared to C group rats. On the other hand, a significant decrease in both variables was detected in the NOT+USGET compared to the NOT group. Muscle power was measured with a grip strength test, obtaining far better performances in NOT+USGET rats when compared to NOT rats. Moreover, the USGET technique prevented the increase of pro-inflammatory proteins IL-6 and chemokines CCL3 (Chemokine (C-C motif) ligand 3), CCL4 (Chemokine (C-C motif) ligand 4), and CCL5 (Chemokine (C-C motif) ligand 5) with their receptor CCR5 (C-C chemokine receptor type 5), induced by notexin in the quadriceps. At the same time, the study evidenced a decrease in both CCR8 (C-C chemokine receptor type 5,) and NF-ᴋB (nuclear factor- ᴋB) expressions after USGET treatment. On the other hand, we obtained evidence that demonstrated anti-inflammatory properties of the USGET technique, thus being the increase in IL-10 (Interleukin 10) and IL-13 (Interleukin 13) in the NOT+USGET group compared to the NOT group. Furthermore, when applying NSGET after damage, an increase in anti-inflammatory mediators and reduction of pro-inflammatory mediators, which, overall, promoted muscle regeneration, was observed. These results support the idea that the NSGET technique improves muscle recovery after toxic damages, which would justify its employment.

An artificial intelligence algorithm for analyzing acetaminophen-associated toxic hepatitis

INTRODUCTION

Very little artificial intelligence (AI) work has been performed to investigate acetaminophen-associated hepatotoxicity. The objective of this study was to develop an AI algorithm for analyzing weighted features for toxic hepatitis after acetaminophen poisoning.

METHODS

The medical records of 187 patients with acetaminophen poisoning treated at Chang Gung Memorial Hospital were reviewed. Patients were sorted into two groups according to their status of toxic hepatitis. A total of 40 clinical and laboratory features recorded on the first day of admission were selected for algorithm development. The random forest classifier (RFC) and logistic regression (LR) were used for artificial intelligence algorithm development.

RESULTS

The RFC-based AI model achieved the following results: accuracy = 92.5 ± 2.6%; sensitivity = 100%; specificity = 60%; precision = 92.3 ± 3.4%; and F1 = 96.0 ± 1.8%. The area under the receiver operating characteristic curve (AUROC) was approximately 0.98. The LR-based AI model achieved the following results: accuracy = 92.00 ± 2.9%; sensitivity = 100%; specificity = 20%; precision = 92.8 ± 3.4%; recall = 98.8 ± 3.4%; and F1 = 95.6 ± 1.5%. The AUROC was approximately 0.68. The weighted features were calculated, and the 10 most important weighted features for toxic hepatitis were aspartate aminotransferase (ALT), prothrombin time, alanine aminotransferase (AST), time to hospital, platelet count, lymphocyte count, albumin, total bilirubin, body temperature and acetaminophen level.

CONCLUSION

The top five weighted features for acetaminophen-associated toxic hepatitis were ALT, prothrombin time, AST, time to hospital and platelet count.

Cost Savings and Efficacy in Management of Paracetamol Poisoning in a 23-hours Emergency Department Observation Unit: A Comparison to Inpatient Care

Introduction

Emergency department observation units (EDOU) have been shown to be effective in decreasing hospitalization rates and length of stay (LOS) for various conditions. However, cost savings and efficacy in the management of poisoning in EDOU have not been widely studied. The objective of our study is to compare the costs and effectiveness of managing paracetamol poisoned patients in the EDOU with those treated in the inpatient wards.

Methods

We conducted a historical controlled observational study comparing paracetamol-poisoned patients (who received at least 21 hours of IV N-acetylcysteine [NAC]) admitted to the EDOU during 2013-2014 with similar patients admitted to inpatient ward during 2011, 2013-2014. 

Results

We found 136 patients admitted to the inpatient ward and 95 to our EDOU due to paracetamol poisoning but only 78 and 39 patients respectively fulfilled the inclusion criteria. Between the EDOU and inpatient ward groups, we found similar demographics, poisoning presentation, treatment, and adverse event profiles. There were no fatalities and only two patients (one from each group) developed hepatotoxicity. The "medical" length of stay was 31.9 hours shorter in the EDOU group compared to the inpatient ward group (23.3 versus 55.2 hours). EDOU patients have statistically significant savings (comparing bill size) of S$784 per patient.

Conclusions

Admission to the EDOU resulted in significant cost savings and 58% decreased LOS when compared to inpatient wards. The EDOU is a cost-effective and safe alternative for the management of selected paracetamol poisonings requiring NAC. Further studies would be needed to verify these results. 

Acetaminophen is Undetectable in Plasma From More Than Half of Patients Believed to Have Acute Liver Failure Due to Overdose

BACKGROUND & AIMS

Evaluation of patients with acute liver injury (ALI) or acute liver failure (ALF) often includes measurement of plasma levels of acetaminophen, to determine exposure and/or toxicity. However, once liver injury has developed, acetaminophen might be undetectable in plasma. We investigated the association between level of acetaminophen measured and outcomes of patients designated as having ALF or ALI due to acetaminophen toxicity.

METHODS

We performed a retrospective analysis of data from 434 subjects in the Acute Liver Failure Study Group who met criteria for ALF (coagulopathy and hepatic encephalopathy within 26 weeks of the first symptoms, without pre-existing liver disease) or ALI (severe liver injury with coagulopathy but no encephalopathy) due to acetaminophen toxicity from January 1, 2010 through December 31, 2014. We collected data on patient demographics, biochemical features, reported acetaminophen use, N-acetylcysteine therapy, liver transplant, and outcomes. Descriptive statistics were used to assess patient demographics, clinical characteristics, and outcomes whereas differences in continuous variables between patients with vs without acetaminophen detection on admission were analyzed using the Wilcoxon rank-sum test. The primary aim was to determine the proportion of patients with detectable plasma levels of acetaminophen.

RESULTS

Acetaminophen was undetectable in serum samples from 227 patients (52%). There were no significant differences between groups of patients with detectable vs undetectable levels in demographic features, alcohol use, median levels of alanine aspartate, or use of N-acetylcysteine (given to 94.7% of patients with detectable acetaminophen vs 95.9% of those with undetectable acetaminophen; P=.63). We observed a significant difference in median dose taken between patients with detectable (29,500 mg; interquartile range, 15,000 mg-50,007 mg) vs no detectable parent compound (14,950 mg; interquartile range, 3960 mg-25,000) (P=.003). A lower proportion of patients with detectable plasma levels of acetaminophen (72.3%) survived without a liver transplant than of patients with undetectable levels (86.3%) in univariate analysis (P=.0006), although this was not significant in multivariable analysis (P=.12). Although most patients had unintentional overdoses, a higher proportion of patients with suicidal overdoses (43%) had detectable levels of acetaminophen than patients with accidental overdoses (29.3%; P=.01).

CONCLUSION

More than half of patients who present at the hospital with acetaminophen-induced ALI or ALF have undetectable levels of acetaminophen. Clinicians should not exclude acetaminophen toxicity because of undetectable levels or withhold N-acetylcysteine for patients with ALI or ALF when acetaminophen toxicity is suspected.

An Unexpected Role of Cholesterol Sulfotransferase and its Regulation in Sensitizing Mice to Acetaminophen-Induced Liver Injury

Overdose of acetaminophen (APAP) is the leading cause of acute liver failure (ALF) in the United States. The sulfotransferase-mediated sulfation of APAP is widely believed to be a protective mechanism to attenuate the hepatotoxicity of APAP. The cholesterol sulfotransferase SULT2B1b is best known for its activity in catalyzing the sulfoconjugation of cholesterol to synthesize cholesterol sulfate. SULT2B1b can be transcriptionally and positively regulated by the hepatic nuclear factor 4α (HNF4α). In this study, we uncovered an unexpected role for SULT2B1b in APAP toxicity. Hepatic overexpression of SULT2B1b sensitized mice to APAP-induced liver injury, whereas ablation of the Sult2B1b gene in mice conferred resistance to the APAP hepatotoxicity. Consistent with the notion that Sult2B1b is a transcriptional target of HNF4α, overexpression of HNF4α sensitized mice or primary hepatocytes to APAP-induced hepatotoxicity in a Sult2B1b-dependent manner. We conclude that the HNF4α-SULT2B1b axis has a unique role in APAP-induced acute liver injury, and SULT2B1b induction might be a risk factor for APAP hepatotoxicity.

Nebulised N-Acetylcysteine for Unresponsive Bronchial Obstruction in Allergic Brochopulmonary Aspergillosis: A Case Series and Review of the Literature

Many chronic lung diseases are characterized by the hypersecretion of mucus. In these conditions, the administration of mucoactive agents is often indicated as adjuvant therapy. N-acetylcysteine (NAC) is a typical example of a mucolytic agent. A retrospective review of patients with pulmonary aspergillosis treated at the National Aspergillosis Centre in Manchester, United Kingdom, with NAC between November 2015 and November 2017 was carried out. Six Caucasians with Aspergillus lung disease received NAC to facilitate clearance of their viscid bronchial mucus secretions. One patient developed immediate bronchospasm on the first dose and could not be treated. Of the remainder, two (33%) derived benefit, with increased expectoration and reduced symptoms. Continued response was sustained over 6–7 months, without any apparent toxicity. In addition, a systematic review of the literature is provided to analyze the utility of NAC in the management of respiratory conditions which have unresponsive bronchial obstruction as a feature.

Interventions for paracetamol (acetaminophen) overdose

BACKGROUND

Paracetamol (acetaminophen) is the most widely used non-prescription analgesic in the world. Paracetamol is commonly taken in overdose either deliberately or unintentionally. In high-income countries, paracetamol toxicity is a common cause of acute liver injury. There are various interventions to treat paracetamol poisoning, depending on the clinical status of the person. These interventions include inhibiting the absorption of paracetamol from the gastrointestinal tract (decontamination), removal of paracetamol from the vascular system, and antidotes to prevent the formation of, or to detoxify, metabolites.

OBJECTIVES

To assess the benefits and harms of interventions for paracetamol overdosage irrespective of the cause of the overdose.

SEARCH METHODS

We searched The Cochrane Hepato-Biliary Group Controlled Trials Register (January 2017), CENTRAL (2016, Issue 11), MEDLINE (1946 to January 2017), Embase (1974 to January 2017), and Science Citation Index Expanded (1900 to January 2017). We also searched the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov database (US National Institute of Health) for any ongoing or completed trials (January 2017). We examined the reference lists of relevant papers identified by the search and other published reviews.

SELECTION CRITERIA

Randomised clinical trials assessing benefits and harms of interventions in people who have ingested a paracetamol overdose. The interventions could have been gastric lavage, ipecacuanha, or activated charcoal, or various extracorporeal treatments, or antidotes. The interventions could have been compared with placebo, no intervention, or to each other in differing regimens.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted data from the included trials. We used fixed-effect and random-effects Peto odds ratios (OR) with 95% confidence intervals (CI) for analysis of the review outcomes. We used the Cochrane 'Risk of bias' tool to assess the risks of bias (i.e. systematic errors leading to overestimation of benefits and underestimation of harms). We used Trial Sequential Analysis to control risks of random errors (i.e. play of chance) and GRADE to assess the quality of the evidence and constructed 'Summary of findings' tables using GRADE software.

MAIN RESULTS

We identified 11 randomised clinical trials (of which one acetylcysteine trial was abandoned due to low numbers recruited), assessing several different interventions in 700 participants. The variety of interventions studied included decontamination, extracorporeal measures, and antidotes to detoxify paracetamol's toxic metabolite; which included methionine, cysteamine, dimercaprol, or acetylcysteine. There were no randomised clinical trials of agents that inhibit cytochrome P-450 to decrease the activation of the toxic metabolite N-acetyl-p-benzoquinone imine.Of the 11 trials, only two had two common outcomes, and hence, we could only meta-analyse two comparisons. Each of the remaining comparisons included outcome data from one trial only and hence their results are presented as described in the trials. All trial analyses lack power to access efficacy. Furthermore, all the trials were at high risk of bias. Accordingly, the quality of evidence was low or very low for all comparisons. Interventions that prevent absorption, such as gastric lavage, ipecacuanha, or activated charcoal were compared with placebo or no intervention and with each other in one four-armed randomised clinical trial involving 60 participants with an uncertain randomisation procedure and hence very low quality. The trial presented results on lowering plasma paracetamol levels. Activated charcoal seemed to reduce the absorption of paracetamol, but the clinical benefits were unclear. Activated charcoal seemed to have the best risk:benefit ratio among gastric lavage, ipecacuanha, or supportive treatment if given within four hours of ingestion. There seemed to be no difference between gastric lavage and ipecacuanha, but gastric lavage and ipecacuanha seemed more effective than no treatment (very low quality of evidence). Extracorporeal interventions included charcoal haemoperfusion compared with conventional treatment (supportive care including gastric lavage, intravenous fluids, and fresh frozen plasma) in one trial with 16 participants. The mean cumulative amount of paracetamol removed was 1.4 g. One participant from the haemoperfusion group who had ingested 135 g of paracetamol, died. There were no deaths in the conventional treatment group. Accordingly, we found no benefit of charcoal haemoperfusion (very low quality of evidence). Acetylcysteine appeared superior to placebo and had fewer adverse effects when compared with dimercaprol or cysteamine. Acetylcysteine superiority to methionine was unproven. One small trial (low quality evidence) found that acetylcysteine may reduce mortality in people with fulminant hepatic failure (Peto OR 0.29, 95% CI 0.09 to 0.94). The most recent randomised clinical trials studied different acetylcysteine regimens, with the primary outcome being adverse events. It was unclear which acetylcysteine treatment protocol offered the best efficacy, as most trials were underpowered to look at this outcome. One trial showed that a modified 12-hour acetylcysteine regimen with a two-hour acetylcysteine 100 mg/kg bodyweight loading dose was associated with significantly fewer adverse reactions compared with the traditional three-bag 20.25-hour regimen (low quality of evidence). All Trial Sequential Analyses showed lack of sufficient power. Children were not included in the majority of trials. Hence, the evidence pertains only to adults.

AUTHORS' CONCLUSIONS

These results highlight the paucity of randomised clinical trials comparing different interventions for paracetamol overdose and their routes of administration and the low or very low level quality of the evidence that is available. Evidence from a single trial found activated charcoal seemed the best choice to reduce absorption of paracetamol. Acetylcysteine should be given to people at risk of toxicity including people presenting with liver failure. Further randomised clinical trials with low risk of bias and adequate number of participants are required to determine which regimen results in the fewest adverse effects with the best efficacy. Current management of paracetamol poisoning worldwide involves the administration of intravenous or oral acetylcysteine which is based mainly on observational studies. Results from these observational studies indicate that treatment with acetylcysteine seems to result in a decrease in morbidity and mortality, However, further evidence from randomised clinical trials comparing different treatments are needed.

New potential biomarkers of acetaminophen-induced hepatotoxicity

Acetaminophen (APAP) is one of the most common antipyretic and analgesic drugs. Despite various precautions patients use APAP in amounts exceeding acceptable daily doses. APAP overdosing contributes to APAP intoxication, which leads to acute liver injury or necessity of exigent liver transplantation. Biomarkers that can be helpful in early diagnosis of liver injury during APAP overdosing are studied worldwide. This review presents recent reports on new potential biomarkers and their prospective application in clinical practice.

Current and future directions in the treatment and prevention of drug-induced liver injury: a systematic review

While the pace of discovery of new agents, mechanisms and risk factors involved in drug-induced liver injury (DILI) remains brisk, advances in the treatment of acute DILI seems slow by comparison. In general, the key to treating suspected DILI is to stop using the drug prior to developing irreversible liver failure. However, predicting when to stop is an inexact science, and commonly used ALT monitoring is an ineffective strategy outside of clinical trials. The only specific antidote for acute DILI remains N-acetylcysteine (NAC) for acetaminophen poisoning, although NAC is proving to be beneficial in some cases of non-acetaminophen DILI in adults. Corticosteroids can be effective for DILI associated with autoimmune or systemic hypersensitivity features. Ursodeoxycholic acid, silymarin and glycyrrhizin have been used to treat DILI for decades, but success remains anecdotal. Bile acid washout regimens using cholestyramine appear to be more evidenced based, in particular for leflunomide toxicity. For drug-induced acute liver failure, the use of liver support systems is still investigational in the United States and emergency liver transplant remains limited by its availability. Primary prevention appears to be the key to avoiding DILI and the need for acute treatment. Pharmacogenomics, including human leukocyte antigen genotyping and the discovery of specific DILI biomarkers offers significant promise for the future. This article describes and summarizes the numerous and diverse treatment and prevention modalities that are currently available to manage DILI.

Kind and estimated stocking amount of antidotes for initial treatment for acute poisoning at emergency medical centers in Korea

Antidotes for toxicological emergencies can be life-saving. However, there is no nationwide estimation of the antidotes stocking amount in Korea. This study tried to estimate the quantities of stocking antidotes at emergency department (ED). An expert panel of clinical toxicologists made a list of 18 emergency antidotes. The quantity was estimated by comparing the antidote utilization frequency in a multicenter epidemiological study and the nation-wide EDs' data of National Emergency Department Information System (NEDIS). In an epidemiological study of 11 nationwide EDs from January 2009 to December 2010, only 92 (1.9%) patients had been administered emergency antidotes except activated charcoal among 4,870 cases of acute adult poisoning patients. Comparing with NEDIS data, about 1,400,000 patients visited the 124 EDs nationwide due to acute poisoning and about 103,348 adult doses of the 18 emergency antidotes may be required considering poisoning severity score. Of these, 13,224 (1.9%) adult doses of emergency antidotes (575 of atropine, 144 of calcium gluconate or other calcium salts, 2,587 of flumazenil, 3,450 of N-acetylcysteine, 5,893 of pralidoxime, 287 of hydroxocobalamin, 144 of sodium nitrite, and 144 of sodium thiosulfate) would be needed for maintaining the present level of initial treatment with emergency antidotes at EDs in Korea.

An Update on Treatment of Drug-Induced Liver Injury

Drug-induced liver injury (DILI) has been linked to more than 1,000 medications and remains the most common cause of acute liver failure in the United States. Here, we review the most current literature regarding treatment and make recommendations for the management of this relatively common disease. Since treatment of DILI remains largely elusive, recent studies have attempted to define new management strategies for these difficult patients. Early diagnosis and withdrawal of the suspected medication is the mainstay of treatment of DILI. For acetaminophen and Amanita mushroom poisoning, there are specific therapies in use. Finally, there are other possible management modalities for DILI, including corticosteroids and ursodeoxycholic acid.

Outcomes of patients with acetaminophen-associated toxic hepatitis at a far east poison center

BACKGROUND

There is an overall paucity of data regarding the outcomes of patients with acetaminophen-associated toxic hepatitis in Taiwan. Therefore, the purpose of this study was to recruit a larger number of patients and to examine the clinical features, the degrees of toxic hepatitis, the physiological markers, and the clinical outcomes after intentional acetaminophen poisoning, and to determine what association, if any, might exist between these findings.

METHODS

We examined the medical records of 187 patients with intentional acetaminophen poisoning who were examined at Chang Gung Memorial Hospital between 2000 and 2011. Patients were categorized into 2 groups according to hepatic complications, i.e. with (n = 15) or without (n = 172) toxic hepatitis. Demographic, clinical, and laboratory data were collected, and the mortality rate was analyzed.

RESULTS

It was found that patients with toxic hepatitis had higher serum acetaminophen level (P = 0.007), but they also arrived to the hospital later (P < 0.001) than patients without toxic hepatitis. Furthermore, patients with toxic hepatitis showed higher incidences of acute respiratory failure (P = 0.012) than those shown by patients who did not have hepatitis. The laboratory examinations also revealed greater degrees of granulocytosis (P < 0.001) and poorer liver function tests (P < 0.001) in patients with hepatitis than in patients without hepatitis. Nevertheless, a univariate logistic regression model failed to identify any significant risk factors for toxic hepatitis complication after ingestion (P > 0.05). At the end of the analysis, 1 patient with toxic hepatitis died of liver failure. Finally, there was no significant difference in mortality between patients with and without hepatitis (P = 0.080).

CONCLUSION

The analytical data revealed that toxic hepatitis was not uncommon (15/187 or 8.0%) after acetaminophen overdose. Further studies are warranted.

Acetaminophen administration in a patient with Gilbert's syndrome

The patient was an 8-year-old Japanese girl with Gilbert's syndrome (GS). Based on the DNA analysis, she was homozygous for a T-to-G transversion at nucleotide position 1456 in the UGT1A1 gene, leading to the substitution of aspartate for tyrosine at position 486 of the UGT1A1 enzyme. Because this mutation is located in an exon common to UGT1A genes, all the UGT1A enzymes may be affected. It is well-known that UGT1A1, UGT1A6 and UGT1A9 enzymes glucuronidate acetaminophen. To evaluate acetaminophen tolerance in the patient, serum acetaminophen levels were determined after oral administration of acetaminophen (15 mg/kg). The maximum serum acetaminophen level reached (12.8 µg/mL) was far below the toxic level. The finding suggested that the usual therapeutic dose of acetaminophen is safe for the GS patient. The combination of mutation analysis in UGT1A1 and acetaminophen loading test may be useful to avoid adverse effect in GS patients.

Pharmacy student knowledge retention after completing either a simulated or written patient case

OBJECTIVE

To determine pharmacy students' knowledge retention from and comfort level with a patient-case simulation compared with a written patient case.

DESIGN

Pharmacy students were randomly assigned to participate in either a written patient case or a simulated patient case in which a high-fidelity mannequin was used to portray a patient experiencing a narcotic and acetaminophen overdose.

ASSESSMENT

Participants' responses on a multiple-choice test and a survey instrument administered before the case, immediately after the case, and 25 days later indicated that participation in the simulated patient case did not result in greater knowledge retention or comfort level than participation in the written patient case. Students' knowledge improved post-intervention regardless of which teaching method was used.

CONCLUSIONS

Although further research is needed to determine whether the use of simulation in the PharmD curriculum is equivalent or superior to other teaching methods, students' enthusiasm for learning in a simulated environment where they can safely apply patient care skills make this technology worth exploring.

A review of the evidence concerning hepatic glutathione depletion and susceptibility to hepatotoxicity after paracetamol overdose

Paracetamol (acetaminophen) poisoning is common throughout the world. The management of nonstaggered (acute) paracetamol overdose is based on the plasma paracetamol concentration plotted on a treatment nomogram. In the UK there are two treatment lines on this nomogram, with the lower treatment line used for individuals felt to be at ‘high risk’ of paracetamol-related hepatotoxicity either as a result of induction of cytochrome P450 isoenzymes or reduction of intrahepatic glutathione. In this article we review the risk factors that, in current guidelines, are felt to increase risk due to a reduction in intrahepatic glutathione concentrations. Based on our review of the published literature, we feel that cystic fibrosis, acute viral illness, malnutrition, and eating disorders such as anorexia nervosa are likely to be associated with reduction in intrahepatic glutathione concentrations, and that this risk is likely to be related to malnutrition secondary to the disease. Chronic hepatitis C infection is also associated with reduced glutathione concentrations, although this appears to be independent of any associated malnutrition. Ageing and acute fasting are not associated with an increased risk of paracetamol-related hepatotoxicity due to reductions in glutathione concentrations. Finally, the evidence for HIV infection is inconclusive, particularly as the majority of studies were conducted in the pre-anti-viral treatment (HAART) era; however it is likely that patients with symptomatic HIV/AIDS have reduced glutathione concentrations due to associated malnutrition. Although there have been few studies which have specifically investigated whether there is an association between reduced intrahepatic glutathione concentrations and increased risk of paracetamol-related hepatotoxicity, in our opinion, it is likely that the above conditions that are associated with reduced glutathione concentrations, will be associated with an increased risk of paracetamol-related hepatotoxicity.

Does cytochrome P450 liver isoenzyme induction increase the risk of liver toxicity after paracetamol overdose?

Paracetamol (acetaminophen, N-acetyl-p-aminophenol, 4-hydroxyacetanilide) is the most common cause of acute liver failure in developed countries. There are a number of factors which potentially impact on the risk of an individual developing hepatotoxicity following an acute paracetamol overdose. These include the dose of paracetamol ingested, time to presentation, decreased liver glutathione, and induction of cytochrome P450 (CYP) isoenzymes responsible for the metabolism of paracetamol to its toxic metabolite N-acetyl-p-benzoquinoneimine (NAPQI). In this paper, we review the currently published literature to determine whether induction of relevant CYP isoenzymes is a risk factor for hepatotoxicity in patients with acute paracetamol overdose. Animal and human in vitro studies have shown that the CYP isoenzyme responsible for the majority of human biotransformation of paracetamol to NAPQI is CYP2E1 at both therapeutic and toxic doses of paracetamol. Current UK treatment guidelines suggest that patients who use a number of drugs therapeutically should be treated as “high-risk” after paracetamol overdose. However, based on our review of the available literature, it appears that the only drugs for which there is evidence of the potential for an increased risk of hepatotoxicity associated with paracetamol overdose are phenobarbital, primidone, isoniazid, and perhaps St John’s wort. There is no evidence that other drugs often quoted as increasing risk, such as carbamazepine, phenytoin, primidone, rifampicin, rifabutin, efavirenz, or nevirapine, should be considered risk factors for hepatotoxicity in patients presenting with acute paracetamol overdose.

Understanding and managing patients with chronic pain

The specialty of oral and maxillofacial surgery has had at its core the foundations of anesthesia and pain and anxiety control. This article attempts to refamiliarize the reader with clinical pearls helpful in the management of patients with chronic pain conditions. The authors also hope to highlight the interplay of chronic pain and psychology as it relates to the oral and maxillofacial surgery patient. To that end, the article outlines and reviews the neurophysiology of pain, the definitions of pain, conditions encountered by the oral and maxillofacial surgeon that produce chronic pain, the psychological impact and comorbidities associated with patients experiencing chronic pain conditions, and concepts of multimodal treatment for patients experiencing chronic pain conditions.

Utility of serum lactate to predict drug-overdose fatality

CONTEXT

Poisoning is the second leading cause of injury-related fatality in the United States. An elevated serum lactate concentration identifies medical and surgical patients at risk for death; however, its utility in predicting death in drug overdose is controversial and unclear.

OBJECTIVE

We aimed to evaluate the prognostic utility of serum lactate concentration for fatality in emergency department (ED) patients with acute drug overdose.

MATERIALS AND METHODS

This was a case-control study at two urban university teaching hospitals affiliated with a regional poison control center. Data were obtained from electronic medical records, poison center data, and the office of the chief medical examiner. Controls were consecutive acute drug overdoses over a 1-year period surviving to hospital discharge. Cases were subjects over a 7-year period with fatality because of drug overdose. Serum lactate concentration was obtained from the initial blood draw in the ED and correlated with fatality.

RESULTS

During the study period, 873 subjects were screened with 50 cases and 100 controls included. Drug exposures and baseline characteristics were similar between groups. Mean lactate concentration (mmol/L) was 9.88 ± 6.7 for cases and 2.76 ± 2.9 for controls (p < 0.001). The receiver operating characteristic area under the curve for prediction of fatality was 0.87 (95% CI: 0.81-0.94). The optimal lactate cutpoint was 3.0 mmol/L (84% sensitivity, 75% specificity), which conferred a 15.8-fold increase in odds of fatality (p < 0.001).

CONCLUSION

In this derivation study, serum lactate concentration had excellent prognostic utility to predict drug-overdose fatality. Prospective validation in the ED evaluation of drug overdoses is warranted.

Delphi consensus on the feasibility of translating the ACEP clinical policies into computerized clinical decision support

Clinical practice guidelines are developed to reduce variations in clinical practice, with the goal of improving health care quality and cost. However, evidence-based practice guidelines face barriers to dissemination, implementation, usability, integration into practice, and use. The American College of Emergency Physicians (ACEP) clinical policies have been shown to be safe and effective and are even cited by other specialties. In spite of the benefits of the ACEP clinical policies, implementation of these clinical practice guidelines into physician practice continues to be a challenge. Translation of the ACEP clinical policies into real-time computerized clinical decision support systems could help address these barriers and improve clinician decision making at the point of care. The investigators convened an emergency medicine informatics expert panel and used a Delphi consensus process to assess the feasibility of translating the current ACEP clinical policies into clinical decision support content. This resulting consensus document will serve to identify limitations to implementation of the existing ACEP Clinical Policies so that future clinical practice guideline development will consider implementation into clinical decision support at all stages of guideline development.

Expert consensus guidelines for stocking of antidotes in hospitals that provide emergency care

STUDY OBJECTIVE

We developed recommendations for antidote stocking at hospitals that provide emergency care.

METHODS

An expert panel representing diverse perspectives (clinical pharmacology, clinical toxicology, critical care medicine, clinical pharmacy, emergency medicine, internal medicine, pediatrics, poison centers, pulmonary medicine, and hospital accreditation) was formed to create recommendations for antidote stocking. Using a standardized summary of the medical literature, the primary reviewer for each antidote proposed guidelines for antidote stocking to the full panel. The panel used a formal iterative process to reach their recommendation for the quantity of an antidote that should be stocked and the acceptable period for delivery of each antidote.

RESULTS

The panel recommended consideration of 24 antidotes for stocking. The panel recommended that 12 of the antidotes be available for immediate administration on patient arrival. In most hospitals, this period requires that the antidote be stocked in the emergency department. Another 9 antidotes were recommended for availability within 1 hour of the decision to administer, allowing the antidote to be stocked in the hospital pharmacy if the hospital has a mechanism for prompt delivery of antidotes. The panel identified additional antidotes that should be stocked by the hospital but are not usually needed within the first hour of treatment. The panel recommended that each hospital perform a formal antidote hazard vulnerability assessment to determine the need for antidote stocking in that hospital.

CONCLUSION

The antidote expert recommendations provide a tool to be used in creating practices for appropriate and adequate antidote stocking in hospitals that provide emergency care.

Acetylcysteine for acetaminophen poisoning

A 25-year-old man presents to the emergency department with a toothache. During the evaluation, the physician determines that the patient has been taking large doses of over-the-counter acetaminophen along with an acetaminophen–hydrocodone product for the past 5 days. His daily dose of acetaminophen has been 12 g per day (maximum recommended dose, 4 g per day). He has no other medical problems and typically consumes two beers a day. The patient has no symptoms beyond his toothache, is not icteric, and has no hepatomegaly or right-upper-quadrant tenderness. His serum acetaminophen concentration 8 hours after the most recent dose is undetectable. His serum alanine aminotransferase concentration is 75 IU per liter, his serum bilirubin concentration is 1.2 mg per deciliter (20.5 μmol per liter), and his international normalized ratio (INR) is 1.1. The emergency department physician contacts the regional poison-control center, which recommends treatment with acetylcysteine.