Accuracy of a Glycerol Dehydrogenase Assay for Ethylene Glycol Detection

INTRODUCTION

Ethylene glycol (EG) is a frequently considered toxicant in poisoned patients. Definitive diagnosis relies on gas chromatography (GC), but this is unavailable at most hospitals. A glycerol dehydrogenase (GDH)-based assay rapidly detects EG. A rapid turnaround time and wide availability of necessary instrumentation suggest this method could facilitate the rapid detection of EG.

METHODS

This is a prospective, observational analysis of banked, remnant serum samples submitted to the laboratory of a large, multi-hospital healthcare system. Samples were submitted over a 12-month period for the explicit purpose of testing for suspected EG ingestion. All samples underwent GC and the GDH-based assay.

RESULTS

Of the 118 analyzed samples, 88 had no EG detected by GC, and 30 were "positive." At the manufacturer's threshold of 6 mg/dL EG, there was 100% (95%CI; 88.7-100) positive percent agreement (PPA) and 98% (92.1-99.6) negative percent agreement (NPA). Adjusted to a threshold of 9 mg/dL, both the PPA and NPA were 100%. Deming regression of the observed concentrations revealed a slope of 1.16 (1.01 to 1.32) and intercept of -5.3 (-8.9 to -1.7).

CONCLUSIONS

The GDH assay provides a sensitive and specific method for the detection and quantification of EG that is comparable to a GC-based method. More widespread use of this rapid, inexpensive assay could improve the care of patients with suspected toxic alcohol exposure. Further study is needed to evaluate the test performance in real-time patient treatment decisions.

Management of Acetaminophen Poisoning in the US and Canada: A Consensus Statement

Importance

The US and Canada currently have no formal published nationwide guidelines for specialists in poison information or emergency departments for the management of acetaminophen poisoning, resulting in significant variability in management.

Objective

To develop consensus guidelines for the management of acetaminophen poisoning in the US and Canada.

Evidence Review

Four clinical toxicology societies (America's Poison Centers, American Academy of Clinical Toxicology, American College of Medical Toxicology, and Canadian Association of Poison Control Centers) selected participants (n = 21). Led by a nonvoting chairperson using a modified Delphi method, the panel created a decision framework and determined the appropriate clinical management of a patient with acetaminophen poisoning. Unique to this effort was the collection of guidelines from most poison centers in addition to systematic collection and review of the medical literature. Comments from review by external organizations were incorporated before the guideline was finalized. The project began in March 2021 and ended in March 2023.

Findings

The search retrieved 84 guidelines and 278 publications. The panel developed guidelines for emergency department management of single or repeated ingestion of acetaminophen. In addition, the panel addressed extended-release formulation, high-risk ingestion, coingestion of anticholinergics or opioids, age younger than 6 years, pregnancy, weight greater than 100 kg, and intravenous acetaminophen use. Differences from current US practice include defining acute ingestion as an ingestion presentation from 4 to 24 hours after overdose was initiated. A revised form of the Rumack-Matthew nomogram was developed. The term massive ingestion was replaced with the term high-risk ingestion and denoted by a specific nomogram line. Other recommendations include specific criteria for emergency department triage, laboratory evaluation and monitoring parameters, defining the role of gastrointestinal decontamination, detailed management of acetylcysteine treatment, associated adverse effects, and stopping criteria for acetylcysteine treatment, as well as criteria for consultation with a clinical toxicologist. Finally, specific treatment considerations, including acetylcysteine dosing, fomepizole administration, and considerations for extracorporeal elimination and transplant evaluation, were addressed.

Conclusions and Relevance

This qualitative study provides a consensus statement on consistent evidence-based recommendations for medical, pharmacy, and nursing education and practice to optimize care of patients with acetaminophen poisoning.

Fomepizole should be used more liberally in paracetamol overdose

Growing clinical and basic science data support the use of fomepizole as an adjunct to N-acetylcysteine in paracetamol poisoning. This safe antidote may be helpful in severely poisoned patients.

Clinical Presentations, Treatments, and Outcomes of Non-native Snake Envenomations in the United States Reported in the North American Snakebite Registry

BACKGROUND

Non-native snake envenomations in the United States are uncommon with much unknown about a patient's presenting signs and symptoms. Antivenoms for non-native snake envenomations are not typically available in hospital pharmacies which may limit their administration. What are the clinical presentations, treatments, and outcomes of non-native snake envenomation cases reported to the North American Snakebite Registry (NASBR) of the Toxicology Investigators Consortium (ToxIC)?

METHODS

This is a descriptive review of all non-native envenomations reported to the NASBR from 2013 to March 2022. Data abstracted included snake species, patient history, clinical signs, diagnostics, treatment (including antivenom usage), follow-up, and final outcome.

RESULTS

We identified 19 non-native snake envenomations resulting from encounters with eleven different species, eight of which belonged to the Viperidae family. The most common presenting symptoms were edema (18 patients), ecchymosis (seven patients), and necrosis (six patients). Systemic effects and hematologic abnormalities were less common. The most common treatments were extremity elevation and analgesia, with two patients receiving mechanical ventilation. Ten patients received antivenom. No patients died. Three patients had loss of mobility in a digit at the last follow-up visit. One patient had permanent tissue loss of a small area on a finger.

CONCLUSIONS

The results of this study suggest that non-native snake envenomations in the United States frequently cause local soft tissue effects and less frequently cause systemic or hematologic effects. Most patients received antivenom, although several patients envenomated by snakes for which a specific antivenom exists did not receive any. Sequelae at the last follow-up of such encounters consisted of local mobility deficits.

Dexmedetomidine in the treatment of toxicologic conditions: a systematic review and review of the toxicology investigators consortium database

INTRODUCTION

Dexmedetomidine is an alpha-2 adrenoceptor agonist which is widely used for sedation. Dexmedetomidine does not suppress the respiratory drive and produces a state of cooperative sedation; it may be associated with beneficial outcomes in the general critical care population. The role of dexmedetomidine in the treatment of toxicologic conditions (excluding alcohol withdrawal) is unclear.

OBJECTIVES

To critically assess and summarize the literature regarding the use of dexmedetomidine in toxicologic conditions other than alcohol withdrawal.

METHODS

We performed a systematic review of the medical literature to identify all existing evidence regarding the use of dexmedetomidine for toxicologic conditions. We excluded reviews and commentary, studies reporting exclusively on alcohol withdrawal, and studies reporting the use of dexmedetomidine to treat iatrogenic sedative withdrawal in the intensive care unit. We also performed a review of the Toxicology Investigators Consortium (ToxIC) database for patients treated with dexmedetomidine.

RESULTS

We identified 98 studies meeting inclusion criteria; 87 of these were case reports or case series, representing 99 unique cases. Eleven articles with other designs were identified, which included 138 patients treated with dexmedetomidine for toxicologic conditions. Ninety-three cases from the ToxIC registry met inclusion criteria. Common indications for dexmedetomidine included stimulant intoxication, sedative withdrawal, serotonin syndrome, antimuscarinic toxidrome, opioid withdrawal, and cannabinoid intoxication. Dexmedetomidine was usually administered by continuous infusion; bolus administration was reported in a minority of cases. Adverse effects were uncommon. The quality of evidence was generally low, given the preponderance of case reports, the rate of missing or poorly reported data, and the near-universal co-administration of other sedatives.

TREATMENT OF STIMULANT POISONING

Fifty-nine patients with stimulant poisoning were treated with dexmedetomidine. There was reasonably good evidence that dexmedetomidine was helpful in the treatment of stimulant poisoning.

TREATMENT OF SEDATIVE WITHDRAWAL

Twenty-two patients with sedative withdrawal were treated with dexmedetomidine. Several case reports of very high-quality suggested efficacy of dexmedetomidine for this indication, particularly for baclofen withdrawal.

TREATMENT OF SEROTONIN SYNDROME

Twenty-six patients with serotonin syndrome were treated with dexmedetomidine. This evidence was of lower quality due to missing clinical details, potential overdiagnosis of serotonin syndrome, and near-universal concomitant treatment with other sedatives.

TREATMENT OF ANTIMUSCARINIC POISONING

Forty-two patients with antimuscarinic poisoning were treated with dexmedetomidine. This evidence was of low quality and was limited by infrequent use of the preferred antidote, physostigmine.

TREATMENT OF OPIOID WITHDRAWAL

Forty-four patients with opioid withdrawal were treated with dexmedetomidine. This evidence was of low quality due to missing clinical details and near-universal concomitant treatment with other agents. The one high-quality trial reported the use of dexmedetomidine in ultra-rapid opioid detoxification, which is not indicated in modern practice.

TREATMENT OF CANNABINOID INTOXICATION

Five patients with cannabinoid intoxication were treated with dexmedetomidine. No definite conclusion can be drawn from the limited available evidence.

DISCUSSION

It is important to distinguish between the use of dexmedetomidine as a general sedative, which is likely to increase as the overall utilization of dexmedetomidine in critical care settings increases, and the use of dexmedetomidine as a specific pharmacologic treatment for a toxicologic condition. Well-established pharmacologic data from animal and human studies suggest dexmedetomidine counteracts stimulant-induced norepinephrine release. The mechanism by which dexmedetomidine treats sedative withdrawal is unclear. Some animal data show that dexmedetomidine may indirectly suppress serotonin release, which may suggest a role for dexmedetomidine in this condition.

CONCLUSIONS

There is a small and generally low-quality body of evidence which suggests that dexmedetomidine may be helpful in the treatment of certain toxicologic conditions, particularly stimulant intoxication and sedative withdrawal. Further high-quality research is needed to clarify the role of dexmedetomidine in patients with toxicologic conditions.

Fomepizole as an adjunctive therapy for acetaminophen poisoning: cases reported to the toxicology investigators consortium (ToxIC) database 2015-2020

INTRODUCTION

Fomepizole inhibits formation of toxic acetaminophen (APAP) metabolites and may prevent or reverse mitochondrial toxicity. Given these mechanisms, it may be beneficial in patients with severe APAP toxicity. Current patterns of use for this indication are not well-studied.

METHODS

This is a secondary analysis of patients enrolled in the Toxicology Investigators Consortium (ToxIC) database from January 2015 to July 2020. We queried cases in which APAP was listed as an ingested agent and fomepizole was also administered. We excluded cases in which APAP was not the primary agent, N-acetylcysteine (NAC) was not administered, or fomepizole was explicitly administered for another indication. Additionally, we sent a survey to each ToxIC site that administered fomepizole for APAP toxicity to better understand when, why, and how they were using it for this indication.

RESULTS

Twenty-five cases of fomepizole administration following an APAP ingestion met our inclusion criteria. There were one to four cases per year between 2015 and 2019 and eight cases in 2020. Seventeen of 25 (68%) cases were for a known acute ingestion. Eighteen of 25 (72%) patients developed hepatotoxicity (AST or ALT > 1000 IU/L) and 10 of 25 (40%) developed coagulopathy (PT > 15s). This was an ill patient population, with 18 of 25 (72%) developing metabolic acidosis (pH <7.20), 12 of 25 (48%) were intubated, 9 of 25 (36%) receiving vasopressors, and 6 of 25 (24%) receiving continuous renal replacement therapy. Overall, mortality was 24%.

CONCLUSION

The use of fomepizole is increasing in frequency in a small subset of critically ill and acutely APAP-poisoned patients.

61-year-old woman • nausea • paresthesia • cold allodynia • Dx?

► Nausea ►Paresthesia ► Cold allodynia.

The Role of the Nephrologist in Management of Poisoning and Intoxication: Core Curriculum 2022

Poisoning is a common problem in the United States. Acid-base disturbances, electrolyte derangements, or acute kidney injury result from severe poisoning from toxic alcohols, salicylates, metformin, and acetaminophen. Lithium is highly sensitive to small changes in kidney function. These poisonings and drug overdoses often require the nephrologist's expertise in diagnosis and treatment, which may require correction of acidosis, administration of selective enzyme inhibitors, or timely hemodialysis. The clinical and laboratory abnormalities associated with the poisonings and drug overdoses can develop rapidly and lead to severe cellular dysfunction and death. Understanding the pathophysiology of the disturbances and their clinical and laboratory findings is essential for the nephrologist to rapidly recognize the poisonings and establish an effective treatment plan. This installment of AJKD's Core Curriculum in Nephrology presents illustrative cases of individual poisonings and drug overdoses and summarizes up to date information on their prevalence, clinical and laboratory findings, pathophysiology, diagnosis, and treatment.

Antithrombotic and Antiplatelet Drug Toxicity

Anticoagulant and antiplatelet drugs target a specific portion of the coagulation cascade or the platelet activation and aggregation pathway. The primary toxicity associated with these agents is hemorrhage. Understanding the pharmacology of these drugs allows the treating clinician to choose the correct antidotal therapy. Reversal agents exist for some of these drugs; however, not all have proven patient-centered outcomes. The anticoagulants covered in this review are vitamin K antagonists, heparins, fondaparinux, hirudin derivatives, argatroban, oral factor Xa antagonists, and dabigatran. The antiplatelet agents reviewed are aspirin, adenosine diphosphate antagonists, dipyridamole, and glycoprotein IIb/IIIa antagonists. Additional notable toxicities are also reviewed.

Ciguatera fish poisoning in the age of discovery and the age of enlightenment

BACKGROUND

Ciguatera fish poisoning (CFP) is the most common poisoning from seafood consumption with an estimated 50,000 cases per year worldwide. Attention to this malady in the English language literature has grown over the past five decades. Endemic areas include the South Pacific Ocean and the Caribbean Sea. It is likely that CFP has been present since ancient times, but records to substantiate this are scarce.

OBJECTIVE

This historical review looks for clues in earlier writings about potential encounters with CFP as Europeans sailed farther from home into these endemic regions with little idea of what awaited them. We divide these records into the Age of Discovery and the Age of Enlightenment.

METHODS

Review of available historical texts written by or about early European explorers with descriptions of illness attributed to eating fish.

RESULTS

Fish poisonings appear in translated writings of early Spanish and Portuguese explorers in the 1500s, the writings of Captain James Cook's voyages to the South Pacific, and in Captain William Bligh's fateful voyage after the Mutiny on the Bounty. The most credible description of CFP comes from an early author in the Spanish colony of Cuba in the late 1700s.

CONCLUSIONS

Although the quality of the observations varies, Parra in Cuba likely experienced CFP. Plausible CFP for Cook in the South Pacific and Locke in the Bahamas as both have elements of CFP. The descriptions from Quiros, Anghira, and Bligh lack sufficient detail to verify or to refute completely the possibility of CFP.

Metabolic and mitochondrial treatments for severe paracetamol poisoning: a systematic review

BACKGROUND

Paracetamol (acetaminophen) remains a leading cause of poisoning in Europe, North America, and Australia. For over four decades, acetylcysteine has been the antidote of choice. However, despite the use of acetylcysteine, some patients who ingest very large doses of paracetamol or who reach hospital late in the course of their poisoning, develop acute liver failure. Some will develop metabolic acidosis indicating mitochondrial toxicity.

OBJECTIVE

We review the experimental and clinical data reported with the use of cimetidine, fomepizole, and calmangafodipir in the treatment of paracetamol toxicity to determine if these treatments alone or in combination with acetylcysteine might be of benefit.

METHODS

We searched Ovid Medline 1946-2020, Embase 1947-2020, Scopus 2004-2020, Cochrane Databases of Systematic Reviews (CDSR), Cochrane Central Register of Controlled Trials (CENTRAL), and clinicaltrials.gov 1997-2020 for records including the concepts of paracetamol poisoning and cimetidine, fomepizole, calmangafodipir, and acetylcysteine. We included basic science studies in animals and all available study types in humans. We reviewed the reference lists of included articles to search for references missed in the original search. We registered the protocol in PROSPERO.

RESULTS

We completed all search strategies on 20 August 2019, 27 January 2020, and 15 June 2020. These produced 6,826 citations. We identified and deleted 2,843 duplicate resulting in a total of 3,856 unique citations. After applying inclusion and exclusion criteria, 89 studies remained. The largest numbers of studies described the past use of cimetidine, and the more recent use of fomepizole.Cimetidine: There is good animal evidence that cimetidine blocks CYP 2E1 with the potential to inhibit the toxic metabolism of paracetamol. Early case reports were inconclusive regarding the benefit to humans in paracetamol poisoning. Two comparative trials found no benefit of cimetidine in paracetamol poisoning, but few patients had severe poisoning.Fomepizole: There is good animal evidence that fomepizole blocks CYP 2E1 with the potential to inhibit the toxic metabolism of paracetamol. There are no comparative trials of fomepizole for acute paracetamol poisoning. Case reports are inconclusive due to multiple other interventions including the use of acetylcysteine in all cases. The benefit of fomepizole as adjunct treatment has not been demonstrated.Calmangafodipir: Calmangafodipir, a drug mimicking superoxide dismutase, has emerged as a potential treatment for severe paracetamol toxicity because the formation of superoxide free radicals appears to explain part of the mitochondrial toxicity of extremely large paracetamol overdoses. Calmangafodipir has reached Phase I/II trial of safety in humans with acute paracetamol overdose. Planning for a Phase III study of efficacy is currently underway.

CONCLUSIONS

The vast majority of patients with acute paracetamol overdose enjoy excellent outcomes with acetylcysteine alone. Although cimetidine and fomepizole inhibit CYP 2E1 in animals, there is insufficient evidence to recommend their use either as a primary treatment or adjunct therapy in paracetamol poisoning. Calmangafodipir remains investigational.

Antidotal use of lipid emulsion - the pendulum swings

Intravenous lipid emulsion (ILE) is a widely accepted treatment for local anesthetic systemic toxicity (LAST), particularly resulting from bupivacaine. The past decade has seen interest in antidotal use of ILE for other poisonings wax and wane. Numerous anecdotes have raised enthusiasm while more rigorous reviews have cast skepticism. The truth may lie between these two poles.We illustrate the recent trends in published reports on ILE. We highlight the gaps in our knowledge and suggest sources of data that may clarify how useful ILE may be for poisonings other than LAST. We offer the example of bupropion, which is hazardous in overdose and which has a Log P (octanol-water partition coefficient) similar to that of bupivacaine.Current data sources including the AAPCC National Poison Data System (NPDS), the ACMT Toxic Investigators Consortium (ToxIC), and a voluntary online registry (www.lipidrescue.org) each give an incomplete view of the problem. We propose analysis of newer NPDS data, which will include ILE as a treatment field code beginning with the 2019 data, and a structured, prospective registry of antidotal use of ILE for poisonings other than LAST.

Acute Liver Failure of unclear cause? Acetaminophen-protein adducts make the diagnosis

Acetaminophen poisoning remains a leading cause of acute liver failure. Some cases may be difficult to diagnose when clinical findings are equivocal, the patient's history is misleading or incomplete, or the acetaminophen concentration is low or undetectable at arrival to care. We describe a case of a medically complicated young child whose acute liver failure had two of these features. Measurement of acetaminophen-protein adducts confirmed acetaminophen as the primary cause of her liver failure.

Validity and reliability of telephone administration of the patient-specific functional scale for the assessment of recovery from snakebite envenomation

Objectives

Although more than 1.8 million people survive snakebite envenomation each year, their recovery is understudied. Obtaining long-term follow-up is challenging in both high- and low-resource settings. The Patient-Specific Functional Scale (PSFS) is an easily administered, well-accepted patient-reported outcome that is validated for assessing limb recovery from snakebite envenomation. We studied whether the PSFS is valid and reliable when administered by telephone.

Methods

This is a secondary analysis of data from a randomized clinical trial. We analyzed the results of PSFS collected in-person on days 3, 7, 14, 21, and 28 and by telephone on days 10, 17, and 24. We assessed the following scale psychometric properties: (a) content validity (ceiling and floor effects), (b) internal structure and consistency (Cronbach’s alpha), and (c) temporal and external validity using Intraclass Correlation Coefficient (ICC). Temporal stability was assessed using Spearman’s correlation coefficient and agreement between adjacent in-person and telephonic assessments with Cohen’s kappa. Bland Altman analysis was used to assess differential bias in low and high score results.

Results

Data from 74 patients were available for analysis. Floor effects were seen in the early post-injury time points (median: 3 (IQR: 0, 5) at 3 days post-enrollment) and ceiling effects in the late time points (median: 9 (IQR: 8, 10). Internal consistency was good to excellent with both in-person (Cronbach α: 0.91 (95%CI 0.88, 0.95)) and telephone administration (0.81 (0.73, 0.89). Temporal stability was also good (ICC: 0.83 (0.72, 0.89) in-person, 0.80 (0.68, 0.88) telephone). A strong linear correlation was found between in-person and telephone administration (Spearman’s ρ: 0.83 (CI: 0.78, 0.84), consistency was assessed as excellent (Cohen’s κ 0.81 (CI: 0.78, 0.84), and Bland Altman analysis showed no systematic bias.

Conclusions

Telephone administration of the PSFS provides valid, reliable, and consistent data for the assessment of recovery from snakebite envenomation.

Snakebite envenomation is an important but neglected tropical disease that impacts millions of people worldwide each year. These bites lead to both death and permanent disability. As they occur in tropical and subtropical regions, they primarily impact people from low-income areas of the world. As potential new treatments are being developed, we must understand their potential benefit in humans before they can be widely disseminated. Performing these human studies requires the ability to determine how patients recovered with these treatments. Having people return for evaluation during recovery is difficult in these low-income regions. We evaluated the ability to use a telephone version of an already accepted measurement of recovery in snakebite, the Patient-Specific Functional Scale. This study demonstrates that using this telephone-administered measure is feasible, valid, and reliable. With the results of this study, we now have an important tool to easily measure recovery in areas where snakebite predominates. This tool will help snakebite envenomation researchers evaluate the potential benefit of new treatments and accelerate the process of bringing new effective treatments to those snakebite patients in the most need.

Comment on “Acetylcysteine in paracetamol poisoning: a perspective of 45 years of use” by D. N. Bateman and J. W. Dear, Toxicol. Res., 2019, 8, 489

We point out an acetylcysteine protocol that a previous article (D. N. Bateman and J. W. Dear, Toxicol. Res., 2019, 8, 489–498) overlooked. The standard concentration protocol uses a uniform concentration of 30 mg mL−1 for all patients to reduce errors in preparation and administration. Usually a single 1 L bag is sufficient for most patients. Various centers in the US and Canada use this approach.

Recovery from Copperhead Snake Envenomation: Role of Age, Sex, Bite Location, Severity, and Treatment

INTRODUCTION

Few data exist to understand the recovery phase of pit viper envenomation. A recently published placebo-controlled clinical trial affords this opportunity. The purpose of this study is to examine the time course of recovery from copperhead snake (Agkistrodon contortrix) envenomation patients managed with and without the use of antivenom, stratified by age, sex, anatomic site of envenomation, initial severity of envenomation, and geographic region.

METHODS

This is a post-hoc subgroup analysis of data from a multi-center double-blinded clinical trial of Fab antivenom (FabAV) vs. placebo. Outcomes were the Patient-Specific Functional Scale (PSFS) score at 3, 7, 10, and 14 days after envenomation. Least-squares mean PSFS score curves were calculated for each subgroup, and repeated measures ANOVA was used to estimate between-group comparisons.

RESULTS

Seventy-two subjects were included, of whom 44 received FabAV. Males demonstrated better overall recovery than females (model predicted PSFS score 6.18 vs 4.99; difference 1.19; 95% CI 0.12 to 2.25; p = 0.029). No sex difference was found in response to FabAV. Overall recovery and effect of FabAV were similar in adult vs adolescent patients, patients with upper vs lower extremity envenomation, and patients with initially mild vs moderate envenomation signs. Analysis by geographic location was not successful due to ANOVA mode instability.

CONCLUSIONS

Male victims of copperhead snake envenomation demonstrate slightly better recovery than females, but response to Fab antivenom overall is similar across all subgroups studied.

Adverse Events in the Efficacy of Crotalidae Polyvalent Immune Fab Antivenom vs Placebo in Recovery from Copperhead Snakebite Trial

OBJECTIVE

To compare the incidence of hypersensitivity reactions following copperhead envenomation treated with Fab antivenom (FabAV) or placebo.

METHODS

Patients with copperhead snakebites received treatment and follow-up in a prospective, randomized, double-blind, placebo-controlled trial of FabAV or placebo. The treatment allocation ratio was 2:1 (FabAV:placebo). All of the included patients received at least one dose of study treatment. We reviewed all treatment-emergent adverse events (AEs) using a previously published scale to classify likely hypersensitivity reactions as mild, moderate, or severe.

RESULTS

We enrolled 74 patients at 13 sites. Forty-five patients received FabAV, and 29 patients received placebo. Five FabAV patients and 4 placebo patients had moderate envenomations; the rest were mild. Twenty-five FabAV patients and 8 placebo patients had at least 1 AE. Mild skin reactions occurred in 11 (24%) FabAV patients (pruritis, urticaria, rash, ecchymosis, erythema) and 1 (3%) placebo patient (pruritis). Moderate gastrointestinal AEs occurred in 7 (16%) FabAV patients (nausea, vomiting, constipation, diarrhea, oral paresthesia) and in 2 (7%) placebo patients (nausea). Respiratory AEs occurred in 3 (7%) FabAV patients (dyspnea, pulmonary embolism, nasal congestion, sneezing) and no placebo patients. Hypotension occurred in 1 patient in each group.

CONCLUSIONS

In a randomized controlled trial of FabAV for copperhead bites, the incidence of hypersensitivity reactions was low. Most reactions were mild skin reactions.

Assessment of Explicitly Stated Interval Change on Noncontrast Head CT Radiology Reports

BACKGROUND AND PURPOSE

Consistent and standardized reporting of interval change for certain diagnoses may improve the clinical utility of radiology reports. The purpose of this study was to assess explicitly stated interval change of various findings in noncontrast head CT reports.

MATERIALS AND METHODS

A retrospective review was performed on successive noncontrast head CT radiology reports from the first 2 weeks of January 2014. Reports with at least 1 prior comparison CT scan were included. Reports with normal examination findings and those that made comparison with only other types of examinations (eg, MR imaging) were excluded. Descriptive and subgroup statistical analyses were performed.

RESULTS

In total, 200 patients with 230 reports and 979 radiographic findings were identified. The average interval between reports was 344.9 ± 695.9 days (range, 0-3556 days). Interval change was mentioned 67.3% (n = 659) of the time for all findings (n = 979). Explicitly stated interval change was significantly associated with nonremote findings (P < .001) and generalized statements of interval change (P < .001). The proportion of interval change reported ranged from 95.3% of the time for hemorrhagic to 36.4% for soft-tissue/osseous categorizations.

CONCLUSIONS

Interval change reporting was variable, mentioned for 67.3% of noncontrast head CT report findings with a prior comparison CT scan. Structured radiology reports may improve the consistent and clear reporting of interval change for certain findings.

5-Oxoproline concentrations in acute acetaminophen overdose

Introduction: Several reports describe high anion gap metabolic acidosis with 5-oxoproline (5-OP) after acetaminophen exposure, including therapeutic use of acetaminophen. The mechanism may involve disordered glutathione metabolism. It is unknown whether acute acetaminophen overdose consistently causes elevations in 5-oxoproline concentration.Methods: We enrolled 23 consecutive adult and adolescent patients with measureable plasma APAP after acute APAP overdose. We used plasma left over in the laboratory after blood tests obtained in clinical care of the patients. We measured plasma [5-OP] by GC/MS. We compared the [5-OP] to laboratory results obtained in the care of these patients to search for correlations. The study had IRB approval.Results: Eighteen patients had non-detectable or normal (<100 μmol/L) 5-oxoproline concentrations. Six more patients had concentrations between 100 μmol/L and 300 μmol/L. There was no significant correlation of 5-OP with APAP, AST, ALT, creatinine, anion gap, INR, or total bilirubin.Discussion: Limitations of the study include small sample size and treatment with IV N-acetylcysteine for all patients with APAP concentrations above the 150 line of the Rumack Matthew nomogram or with hepatotoxicity. We believe that inherited enzyme deficiencies more likely explain cases of 5-oxoprolinemia.Conclusion: Acetaminophen overdose generally results in normal 5-oxoproline concentrations with some patients having slightly elevated 5-oxoproline concentrations.

Current Management of Copperhead Snakebites in Missouri

The past two decades have seen changes to the management of copperhead snakebites. We review the current use of antivenom, analgesics, and laboratory testing as well as the declining role of surgical management.