American Academy of Clinical Toxicology Practice Guidelines on the Treatment of Ethylene Glycol Poisoning. Ad Hoc Committee

Clinical presentation and management of methanol poisoning outbreaks in Riyadh, Saudi Arabia: a retrospective analysis

BACKGROUND

Acute methanol intoxication, whether unintentional or deliberate, necessitates prompt intervention to prevent severe morbidity and mortality. Homemade alcoholic beverages are a frequent source of such poisoning. This retrospective analysis examined two outbreaks of methanol intoxication in Saudi Arabia. It investigated the clinical presentation, implemented management strategies, and any lasting complications (sequelae) associated with these cases. The aim was to assess the potential impact of different treatment modalities and the timeliness of their initiation on patient outcomes.

METHODS

This was a retrospective case series of methanol poisoning cases which presented to the adult emergency department (ED) at King Abdulaziz Medical City (KAMC) in Riyadh, Saudi Arabia. There were two separate outbreaks in the city, the first one was from September 1 to September 10, 2020 and the second one was from May 14 to May 20, 2021. Electronic charts were reviewed, and data were extracted to previously prepared data extraction sheets.

RESULT

From the 22 patients who arrived in the ED alive, the most common complaints were nausea or vomiting followed by altered level of consciousness. About 9% from the patient were hypotensive, 36% were tachycardic, 41% were tachypneic and 4% were having SpO2 < 94%. Brain CT was abnormal in 6 patients. Vision impairment was the most common sequalae of methanol poisoning (7 out of 12 patients who were assessed by ophthalmologist, 58%). When the patients were divided based on severity (mild, moderate, severe), nausea or vomiting and loss of consciousness were the most common complaints among the moderate group while loss of consciousness predominated in the severe group. Two patients presented with low blood pressure and were in the sever group. The severe group had a mean Glasgow Coma Scale (GCS) of 8. Most of the patients in the severity groups underwent the same management apart from those who died or deposited. Eight patients in the severe group had to be intubated.

CONCLUSION

This study demonstrates the multifaceted clinical presentation of methanol poisoning, culminating in a 17.4% mortality rate. Notably, our findings emphasize the critical role of prompt diagnosis and swift initiation of combined fomepizole therapy and hemodialysis in mitigating mortality and minimizing the potential for chronic visual sequelae associated with methanol poisoning.

Emerging progressive atypical acute kidney injury in young children linked to ethylene glycol and diethylene glycol intoxication

BACKGROUND

There had been a sudden surge of unusually severe and rapidly progressing acute kidney injury (AKI) incidence in Indonesia since August 2022 which did not correspond to the rise of COVID-19 incidence. We suspected this was related to ethylene glycol (EG) and diethylene glycol (DEG) intoxication. This study is aimed at describing the clinical and laboratory characteristics of AKI related to D(EG) intoxication in order to spread awareness of the possibility of intoxication in cases of rapidly progressing AKI with unknown etiology.

METHODS

We conducted a cross-sectional study by collecting secondary data from the pediatric AKI registry at a national referral hospital in Jakarta, Indonesia. Data on children admitted from January to November 2022 with diagnosis of stage 3 AKI based on KDIGO criteria were included. Data regarding demographics, symptoms prior to anuria, laboratory results, infection panel including COVID-19 status, treatment administered, and mortality were analyzed.

RESULTS

Sixteen patients tested positive for EG and DEG, all with history of consuming syrup-based medications. High anion gap metabolic acidosis was observed in majority of patients with mean pH 7.33 ± 0.07 and mean anion gap 15.6 ± 7.8 mEq/L. No patient had high osmolal gap (mean osmolal gap 3.46 ± 4.68). One deceased patient, who had kidney biopsy performed, showed severe damage and calcium oxalate crystals in the kidney tissue. Mortality was recorded in six patients (37.5%).

CONCLUSION

Careful history taking of patient's clinical course, including consumption of syrup-based medications and laboratory findings, might aid clinicians to establish a working diagnosis of D(EG) intoxication without needing to wait for blood toxicology test. Early diagnosis and therapy are crucial to prevent substantial mortality.

Combined Ethylene Glycol Poisoning with Methemoglobinemia Due to Antifreeze Ingestion

BACKGROUND

Antifreeze poisoning is potentially life-threatening and often requires multiple antidotal therapies and hemodialysis. Ethylene or propylene glycol toxicity is commonly caused by antifreeze ingestion. However, ingestion of antifreeze is typically not associated with methemoglobinemia. Currently, only one other case of antifreeze ingestion causing combined ethylene glycol poisoning and methemoglobinemia has been reported.

CASE REPORT

A 56-year-old man presented after a witnessed, intentional, large-volume antifreeze ingestion. Evaluation revealed dark brown blood and significantly elevated methemoglobin and ethylene glycol levels. He was successfully treated with methylene blue, fomepizole, and hemodialysis. No other potential cause for methemoglobinemia was elucidated, and further research indicated that minor components of the specific antifreeze product served as an oxidizing agent. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case highlights the impact of minor, unreported product components that may significantly contribute to clinical toxicity, as well as the need to remain vigilant when reviewing product information and potential limitations therein.

Mass Poisoning From Ethylene Glycol at a U.S. Military Base

Ethylene glycol (EG) toxicity is an important cause of toxic alcohol poisoning in the USA with over 5,000 exposures reported annually. While classically characterized by solitary accidental or intentional ingestions, mass toxic alcohol poisoning outbreaks and more rarely collective consumptions (typically of methanol) have been described. We describe an ethylene glycol poisoning from collective ingestion that involved soldiers presenting at William Beaumont Army Medical Center in El Paso, Texas. Eleven soldiers presented to the emergency department over a 12-h period after ingestion of an unknown substance. The first two patients exhibited severe neurologic symptoms, while the remainder were asymptomatic. As serum EG levels were not immediately available, treatment decisions were based on surrogate laboratory values. Two patients received immediate hemodialysis, and fomepizole (FOM) because of severe acidosis with elevated anion and osmolal gaps. These patients developed acute kidney injury with renal recovery within a 3-week period. Two patients with elevated lactate received bicarbonate-based intravenous (IV) fluids and FOM. Two patients received IV fluids only and required prolonged observation for worsening acidosis and/or acute kidney injury. Five patients with normal laboratory values were treated with IV fluids and observation. All patients received cofactors including thiamine and pyridoxine. All patients survived. The outbreak occurred in the setting of limited dialysis resources, limited FOM availability, and in a resource-limited community. Additional guidelines are needed to determine allocation of limited resources, optimal dialysis and FOM treatment course, and comorbid conditions, which may prolong recovery.

Kidney outcomes after methanol and ethylene glycol poisoning: a systematic review and meta-analysis

INTRODUCTION

Ingestions with methanol, ethylene glycol, diethylene glycol, propylene glycol, and isopropanol are rare yet exceedingly dangerous conditions that may require emergent management with kidney replacement therapy. Little is known regarding short- and long-term kidney outcomes post-ingestion.

OBJECTIVES

To comprehensively synthesize existing evidence regarding short- and long-term kidney and other outcomes of adult patients following these poisonings.

METHODS

We developed a search strategy in MEDLINE via OVID and then translated it into other databases including EMBASE (via OVID), PubMed, CENTRAL (via OVID). The databases were searched from their dates of inception to 29 July 2021. A grey literature search was conducted in the International Traditional Medicine Clinical Trial Registry and ClinicalTrials.gov. All interventional and observational studies and case series with ≥ five participants that reported on the outcomes of toxic alcohol (methanol, ethylene glycol, diethylene glycol, propylene glycol and isopropanol) poisonings in adult patients ≥18 years old were included. Studies that reported mortality, kidney outcomes and/or complications attributed to toxic alcohol poisoning were eligible.

RESULTS

The search strategy identified 1,221 citations. Sixty-seven studies (13 retrospective observational studies, one prospective observational study, 53 case series) met inclusion criteria (total N = 2,327 participants). No randomized controlled trials were identified per our prespecified criteria. Generally, included studies had small sample sizes (median of 27 participants) and were of low quality. Methanol and/or ethylene glycol poisoning made up 94.1% of included studies, whereas one study reported on isopropanol and none reported on propylene glycol. Results of the 13 observational studies of methanol and/or ethylene glycol poisoning were pooled for meta-analyses. The pooled in-hospital mortality estimates amongst patients with methanol and ethylene glycol poisoning were 24 and 11%, respectively. A more recent year of publication, female sex and mean age were associated with lower in-hospital mortality amongst individuals with ethylene glycol poisoning. Although hemodialysis was the most frequently employed kidney replacement therapy, the indications for initiation of this therapy were not reported in the majority of studies. At hospital discharge, kidney recovery occurred in 64.7-96.3% of patients with ethylene glycol poisoning. In studies of methanol and/or ethylene glycol poisoning, 2-3.7% of individuals required ongoing dialysis. Only one study reported post-discharge mortality. Furthermore, long-term toxic alcohol-mediated sequelae, such as visual and neurologic outcomes, were scarcely reported.

DISCUSSION

Ingestions of methanol and ethylene glycol were associated with a significant short-term risk of mortality. Although a wealth of literature in the form of case reports and case series exists, high-quality evidence regarding kidney outcomes after these poisonings is lacking. We identified a paucity of standardized reporting in clinical presentations, therapeutics and outcomes amongst adults with toxic alcohol poisoning. Amongst the included studies, there was substantial heterogeneity encompassing study type, outcomes, duration of follow-up and treatment modalities. These sources of heterogeneity restricted our ability to perform comprehensive meta-analyses of all outcomes of interest. An additional limitation is the lack of studies pertaining to propylene glycol and the paucity of data on isopropanol.

CONCLUSIONS

The indications for hemodialysis, long-term kidney recovery and long-term mortality risk vary widely in these poisonings and are inconsistently reported in the literature. This highlights the need for further research with standardized reporting of baseline kidney function, indications for initiation of kidney replacement therapy and short-term and long-term kidney outcomes.

REGISTRATION

This systematic review protocol is registered at PROSPERO, CRD42018101955.

Extracorporeal treatment for ethylene glycol poisoning: systematic review and recommendations from the EXTRIP workgroup

Ethylene glycol (EG) is metabolized into glycolate and oxalate and may cause metabolic acidemia, neurotoxicity, acute kidney injury (AKI), and death. Historically, treatment of EG toxicity included supportive care, correction of acid-base disturbances and antidotes (ethanol or fomepizole), and extracorporeal treatments (ECTRs), such as hemodialysis. With the wider availability of fomepizole, the indications for ECTRs in EG poisoning are debated. We conducted systematic reviews of the literature following published EXTRIP methods to determine the utility of ECTRs in the management of EG toxicity. The quality of the evidence and the strength of recommendations, either strong ("we recommend") or weak/conditional ("we suggest"), were graded according to the GRADE approach. A total of 226 articles met inclusion criteria. EG was assessed as dialyzable by intermittent hemodialysis (level of evidence = B) as was glycolate (Level of evidence = C). Clinical data were available for analysis on 446 patients, in whom overall mortality was 18.7%. In the subgroup of patients with a glycolate concentration ≤ 12 mmol/L (or anion gap ≤ 28 mmol/L), mortality was 3.6%; in this subgroup, outcomes in patients receiving ECTR were not better than in those who did not receive ECTR. The EXTRIP workgroup made the following recommendations for the use of ECTR in addition to supportive care over supportive care alone in the management of EG poisoning (very low quality of evidence for all recommendations): i) Suggest ECTR if fomepizole is used and EG concentration > 50 mmol/L OR osmol gap > 50; or ii) Recommend ECTR if ethanol is used and EG concentration > 50 mmol/L OR osmol gap > 50; or iii) Recommend ECTR if glycolate concentration is > 12 mmol/L or anion gap > 27 mmol/L; or iv) Suggest ECTR if glycolate concentration 8-12 mmol/L or anion gap 23-27 mmol/L; or v) Recommend ECTR if there are severe clinical features (coma, seizures, or AKI). In most settings, the workgroup recommends using intermittent hemodialysis over other ECTRs. If intermittent hemodialysis is not available, CKRT is recommended over other types of ECTR. Cessation of ECTR is recommended once the anion gap is < 18 mmol/L or suggested if EG concentration is < 4 mmol/L. The dosage of antidotes (fomepizole or ethanol) needs to be adjusted during ECTR.

Hemodialysis treatment for poisoning patients in the emergency department

INTRODUCTION

We aimed to evaluate the hemodialysis (HD) use in adult patients after acute poisoning in the emergency department.

METHODS

The study was performed as a retrospective observational cohort study. We analyzed hospital electronic data system and patient files.

RESULTS

A total of 55 patients were included in the study. Among the 10 toxins exposed, the most common were methanol and metformin. The most common indications for HD treatment were: 67.3% (n = 37) for toxin elimination, 20% (n = 11) for treatment-resistant metabolic acidosis, hemodynamic disorder. The most common complication (50.9%) in all patients was central nervous system depression. Ten patients died from ingestion of methanol, one of aluminum phosphide, and one of opioid-sympathomimetic-hallucinogen agents.

CONCLUSION

HD is the most commonly used extracorporeal treatment method in the treatment of poisoning patients. HD should be considered without any delay in treating poisoned patients if there is no response to conventional treatments.

[When a Gap Leads to an Answer]

When a Gap Leads to an Answer Abstract. We report the case of a 22-year-old patient who was found somnolent after previously complaining of nausea, abdominal pain, and vomiting. The main findings were high anion gap metabolic acidosis and lactatemia. Causative was the ingestion of ethylene glycol using a car antifreeze agent with suicidal intent.

Case Report: Early Recognition, Treatment, and Occupational Safety Protection are Crucial for Methanol Toxicity

Background

Despite significant progress in treating methanol poisoning, the lack of training, hazard communication, and occupational safety protection education contributes to the risk of occupational exposure and methanol toxicity. In addition, early diagnosis and timely medical care are essential to reduce the risk of morbidity and mortality, yet it remains a challenging procedure.

Case Report

A 35-year-old man working in a fireworks factory came to our emergency department with acute mental change and progressive disturbance of consciousness. The patient's vital signs were stable, and he presented with enlargement of both pupils with a weak reaction to light. Head computed tomography showed low signal intensities in the bilateral basal ganglia. He was admitted to the neurologic intensive care unit, where additional laboratory workup showed high anion-gap metabolic acidosis. Methanol poisoning was thus considered. Before being treated with sodium bicarbonate infusion, hemodialysis, folate, and high-dose vitamin B, the blood and urine samples were collected for toxicity tests, which turned out to be methanol poisoning. After 8 hours of hemodialysis, the patient's consciousness recovered, but he complained of a complete loss of vision in both eyes. Brain and optic nerve magnetic resonance images showed bilateral symmetric putamen lesions and optic neuropathy. Ophthalmic tests indicated visual pathway impairment and optic disc swelling but no fluorescein leakage. The right eye's vision was partially restored on the third day, but he could only count fingers at 20 cm. Unfortunately, his eyesight ceased to improve during the 6 months of follow-up.

Conclusions

Early diagnosis and prompt treatment will improve the prognosis of methanol poisoning in terms of vision and patient survival. Awareness and supervision of commercial alcohol use are indispensable for similar industrial processes.

Treating ethylene glycol poisoning with alcohol dehydrogenase inhibition, but without extracorporeal treatments: a systematic review

CONTEXT

Ethylene glycol is metabolized to toxic metabolites that cause acute kidney injury, metabolic acidemia, and death. The treatment of patients with ethylene glycol poisoning includes competitively inhibiting alcohol dehydrogenase with ethanol or fomepizole to prevent the formation of toxic metabolites, and extracorporeal treatments such as hemodialysis to remove ethylene glycol and its metabolites. In the absence of significant metabolic acidemia or kidney injury, it is hypothesized that extracorporeal treatments may be obviated without adverse outcomes to the patient if alcohol dehydrogenase inhibitors are used.

OBJECTIVES

The objectives of this study are to: (1) identify indicators predicting ADH inhibitor failure in patients with ethylene glycol poisoning treated with either ethanol or fomepizole for whom extracorporeal treatment was not performed (aside from rescue therapy, see below) (prognostic study), and (2) validate if the anion gap, shown in a previous study to be the best surrogate for the glycolate concentration, is associated with acute kidney injury and mortality (anion gap study).

METHODS

We conducted a systematic review to identify all reported patients with ethylene glycol poisoning treated without extracorporeal treatments but with either fomepizole (fomepizole monotherapy) or ethanol (ethanol monotherapy). Analyses were performed using both one case per patient and all cases (if multiple events were reported for a single patient). Data were compiled regarding poisoning, biochemistry, and outcomes. Treatment failure was defined as mortality, worsening of acid-base status, extracorporeal treatments used as rescue, or a worsening of kidney or neurological function after alcohol dehydrogenase inhibition was initiated. Also, we performed an analysis of previously described anion gap thresholds to determine if they were associated with outcomes such as acute kidney injury and mortality.

RESULTS

Of 115 publications identified, 96 contained case-level data. A total of 180 cases were identified with ethanol monotherapy, and 231 with fomepizole monotherapy. Therapy failure was noted mostly when marked acidemia and/or acute kidney injury were present prior to therapy, although there were cases of failed ethanol monotherapy with minimal acidemia (suggesting that ethanol dosing and/or monitoring may not have been optimal). Ethylene glycol dose and ethylene glycol concentration were predictive of monotherapy failure for ethanol, but not for fomepizole. In the anion gap study (207 cases), death and progression of acute kidney injury were almost nonexistent when the anion gap was less than 24 mmol/L and mostly observed when the anion gap was greater than 28 mmol/L.

CONCLUSION

This review suggests that in patients with minimal metabolic acidemia (anion gap <28 mmol/L), fomepizole monotherapy without extracorporeal treatments is safe and effective regardless of the ethylene glycol concentration. Treatment failures were observed with ethanol monotherapy which may relate to transient subtherapeutic ethanol concentrations or very high ethylene glycol concentrations. The results are limited by the retrospective nature of the case reports and series reviewed in this study and require prospective validation.

Oxidative stress and biochemical indicators in blood of patients addicted to alcohol treated for acute ethylene glycol poisoning

Ethylene glycol (EG), in addition to its neurotoxic and nephrotoxic effects, evokes oxidative stress. The aim of this study was to assess the influence of the ethylene glycol on the biochemical indicators and oxidoreductive balance of patients treated for acute poisoning. The total study group consisted of 56 persons including 26 alcoholics who took EG as a substitute for ethyl alcohol in the course of alcohol dependence syndrome and 30 controls. Severity of poisoning, results of acid-base parameters, biochemical, and toxicological tests as well as biomarkers of the oxidative stress in blood were analyzed during the patients' hospitalization. The key issue was to assess the oxidative stress and biochemical disturbances caused by EG and the type of treatment applied in the course of poisoning. Significant changes in some parameters were found both at time of diagnosis and after treatment initiation (ethanol as an antidote and hemodialysis). The most important differences included the activity of hepatic parameters (aspartate aminotransferase, AST) and oxidative stress markers like catalase (CAT); correlation of the lipid peroxidation products level (TBARS) with urea concentration has been shown. On the last day of the hospitalization, in some cases, the mutual correlation between the evaluated markers were observed, for example, between alanine transaminase (ALT) and glutathione reductase (GR), and urea concentration and glutathione level (GSH/GSSG). The concentration of ions (H⁺) had a major impact on the oxidoreductive balance, correlating with the elevated GR and GSH/GSSG levels.

Analysis of Fomepizole Elimination in Methanol- and Ethylene Glycol-Poisoned Patients

INTRODUCTION

Fomepizole is an anti-metabolite therapy that is used to diminish the toxicity from methanol or ethylene glycol. Although its elimination kinetics have been well described in healthy human subjects, the elimination in poisoned patients have only been described in a few isolated cases. This study was designed to relate the elimination of fomepizole in a series of poisoned patients to that in healthy humans.

METHODS

Plasma samples from 26 patients in the clinical trials of the use of fomepizole for methanol and ethylene glycol poisoning were analyzed for fomepizole concentrations. The elimination of fomepizole was assessed after individual doses, both during and without intermittent hemodialysis.

RESULTS

In methanol- and ethylene glycol-poisoned patients, fomepizole had a volume of distribution of 0.66-0.68 L/kg. After repeated doses of fomepizole, the minimum trough concentration averaged 86-109 µmol/L, which is 10 times higher than the minimum therapeutic concentration. In healthy human subjects, fomepizole elimination follows Michaelis-Menten kinetics and has been calculated as zero-order elimination rates. Zero-order elimination rates averaged 13 and 17 μmol/L/h in methanol and ethylene glycol patients, respectively, compared to 6-19 μmol/L/h in healthy subjects. Elimination during intermittent hemodialysis followed first-order kinetics, with a half-life of 3 h.

CONCLUSIONS

Plasma concentrations during the repeated dosing confirmed that the recommended dosing schedule, with and without intermittent hemodialysis, maintained therapeutic concentrations throughout the treatments. Fomepizole elimination in poisoned patients at therapeutic plasma concentrations appears be similar to that reported previously in healthy human subjects.

Toxic alcohol poisoning characteristics and treatments from 2000 to 2017 at a United States regional poison center

BACKGROUND

Toxic alcohol exposures are an ongoing concern in the United States. In the US, few studies characterize the local epidemiology of toxic alcohols over time.

OBJECTIVES

The objective was to examine the incidence of toxic alcohol ingestions and changes in management over time.

METHODS

This retrospective cohort study evaluates toxic alcohol ingestion phone calls to a regional poison center in the United States covering four states. Data were queried for this poison center from the National Poison Data System (NPDS) using generic codes for each toxic alcohol. Inclusion criteria were ingestion of toxic alcohol, age ≥ 13 years, from January 1, 2000 to Dec 31, 2017. Exclusion criteria were unrelated effects coded in the medical outcome, duplicate data, or incomplete demographic data.

RESULTS

Of 926 subjects (adults and teenagers), 71.5% were male, and the mean age was 34.5 years. Toxic alcohol ingestion was more common in individuals younger than 40 years, with a significant relationship between age and intentional abuse or misuse (p = 0.001). There was also a significant relationship between age and reason for ingestion, with younger patients more likely to be suicidal (p < 0.001). Ethyleneglycol was the most common toxic alcohol. There was no change in the incidence of toxic alcohol ingestions over the study period. The mortality rate was 1.7%, and 31.2%of patients were hospitalized in a critical care unit. Major effects and death were more common in younger patients (p < 0.001). There was a significant difference in medical outcomes based on the type of toxic alcohol(p = 0.03). Fomepizole was the most common treatment. A Poisson regression model found no change in fomepizole use during the study period (p = 0.1). Ethanol administration over the study period increased (p = 0.02), while hemodialysis decreased (p = 0.02).

CONCLUSION

Data obtained from a single regional United States poison center showed low mortality related to toxic alcohol ingestions. The most prevalent toxic alcohol was Ethylene glycol. In all cases, toxic alcohol ingestion was higher in the 20-29-year-old age group. Reasons for ingestion, in most cases, were suicidal. Fomepizole was the most common treatment, ethanol administration as an antidote is rising, and hemodialysis utilization is decreasing. Data may not be nationally representative.

Ethylene Glycol Intoxication Requiring ECMO Support

Ethylene glycol is commonly used in antifreeze, and ingestion of even a small amount can result in acute kidney injury, severe metabolic acidosis, and neurological injury. When cases are recognized early, treatment involves administration of alcohol dehydrogenase inhibitors to prevent conversion to toxic metabolites of glycolate, glyoxolate, and oxalate. In later presentations with more severe renal injury, hemodialysis may be required for clearance of toxic metabolites and supportive care for renal failure. We present the first reported case of severe ethylene glycol intoxication requiring support of extracorporeal membrane oxygenation (ECMO) due to refractory cardiopulmonary collapse.

Outcomes of death and prolonged renal insufficiency in ethylene glycol poisoned patients

BACKGROUND

Despite the severity of ethylene glycol intoxication, there is a paucity of studies that analyze prognostic factors. This study aims to determine prognostic factors with impact on core outcomes like death and prolonged kidney injury (KI) in ethylene glycol poisoned patients.

METHODS

We retrospectively assessed prevalence, clinical and biochemical features in one large data set from two regional hospitals from the North-East region of Romania, between January 2012 and October 2017. Secondly, we compared prognostic factors of cases treated with dialysis plus antidote (N = 28 patients) with cases who received antidote only and supportive therapy (N = 28 patients).

RESULTS

Of the 56 cases included, 16 deaths (28.57%) were recorded. The symptomatology at admission was more severe among patients requiring hemodialysis: a lower mean value for initial pH, lower initial alkaline reserve (AR) and higher mean values for initial serum creatinine (Cr1). The data analysis (survivors/deceased) showed a correlation between pH, Glasgow Coma Score (GCS), and increased mortality. In addition, we found a correlation between initial mean values for pH, AR (mmol/L), Cr1 (mg/dL), and peak Cr24 (mg/dL) with outcomes of RI or death.

CONCLUSIONS

Compared with survivors, patients who died or had prolonged kidney injury were more likely to exhibit clinical signs such as coma, seizures, and acidosis. Hemodialysis and antidote should be started early and continued until acidosis is corrected.

Oral Ethanol Treatment for Ethylene Glycol Intoxication

Ethylene glycol is an odorless, sweet-tasting liquid found in industrial solutions such as antifreeze and windshield wiper fluid. Brake fluid, an automobile transmission liquid, contains poisonous alcohols such as glycol ethers and ethylene glycols. The toxicity of ethylene glycol is associated with toxic metabolite production by the liver enzyme alcohol dehydrogenase. Administration of either intravenous ethanol or fomepizole, both of which competitively inhibit ethylene glycol metabolism by alcohol dehydrogenase and can prevent the production and accumulation of the toxic metabolites, can be used as an antidote. A 42-year-old male car mechanic was transferred to our hospital after accidentally ingesting approximately 100 mL of brake fluid. Immediately after ingestion, he threw up most of the ingested liquid; however, he complained of nausea and throat pain and was moved to our emergency department. The patient was successfully treated with administration of oral ethanol in the form of whisky through a nasogastric tube since neither intravenous ethanol nor fomepizole was available in our hospital at the time of his presentation. Our case demonstrates that oral ethanol can be used as an alternative treatment for patients with ethylene glycol intoxication.

Ethylene Glycol Poisoning with a Near-Normal Osmolal Gap: A Diagnostic Challenge

Ethylene glycol is a colorless, odorless, sweet-tasting liquid commonly found in antifreeze, as well as in industrial agents. It is regarded as one of the toxic alcohols. Ethylene glycol poisoning usually occurs due to ingestion, and its toxicity is mediated by its metabolites, glycolic acid, and oxalate. These metabolites can cause neurological symptoms, gastrointestinal symptoms, and/or renal failure if not diagnosed and treated promptly. The diagnosis can be very challenging as the test used to detect ethylene glycol in the blood may not be readily available or due to an inaccurate history. The treatment of ethylene glycol poisoning consists of supportive care, sodium bicarbonate, and the use of an antidote (ethanol or fomepizole) which inhibits alcohol dehydrogenase and thereby prevents the formation of toxic metabolites. Patients with advanced poisonings may also require dialysis. The diagnosis is usually suggested by a high anion gap metabolic acidosis and an elevated osmolal gap in the setting of a suspected ingestion. Rarely, the osmolal gap may be close to normal which can delay the diagnosis or lead to a misdiagnosis. We report a case of ethylene glycol ingestion with a near-normal osmolal gap.

Unintentional Ethylene Glycol Poisoning in an Adolescent

The differential diagnosis is broad when a patient presents with an altered mental status. Ethylene glycol poisoning, a life-threatening condition, can occur as an intentional self-harm attempt or unintentional consumption. It is metabolized in the liver by a series of enzymes, and the metabolites so formed are responsible for the majority of clinical effects. The diverse range of clinical effects includes central nervous system (CNS), gastrointestinal, cardiovascular system (CVS), pulmonary as well as renal effects. The evidence of metabolic acidosis, elevated anion gap, high osmolal gap, and calcium oxalate crystals in laboratory analysis strongly suggests ethylene glycol poisoning. The treatment traditionally consists of alcohol dehydrogenase inhibitors such as fomepizole or ethanol, and in some cases, hemodialysis is needed as well.

3D Printing for Hip Implant Applications: A Review

There is a rising demand for replacement, regeneration of tissues and organ repairs for patients who suffer from diseased/damaged bones or tissues such as hip pains. The hip replacement treatment relies on the implant, which may not always meet the requirements due to mechanical and biocompatibility issues which in turn may aggravate the pain. To surpass these limitations, researchers are investigating the use of scaffolds as another approach for implants. Three-dimensional (3D) printing offers significant potential as an efficient fabrication technique on personalized organs as it is capable of biomimicking the intricate designs found in nature. In this review, the determining factors for hip replacement and the different fabrication techniques such as direct 3D printing, Fused Deposition Modelling (FDM), Selective Laser Sintering (SLS) and stereolithography (SLA) for hip replacement. The study also covers surface modifications of 3D printed implants and provides an overview on 3D tissue regeneration. To appreciate the current conventional hip replacement practices, the conventional metallic and ceramic materials are covered, highlighting their rationale as the material of choice. Next, the challenges, ethics and trends in the implants' 3D printing are covered and conclusions drawn. The outlook and challenges are also presented here. The knowledge from this review indicates that 3D printing has enormous potential for providing a pathway for a sustainable hip replacement.

[Fomepizole, ethanol or dialysis in the case of life-threatening ethylenglycol intoxication?]

The EXTRIP (EXtracorporeal Treatments In Poisoning) workgroup is a collaborative international effort of pharmacologists, toxicologists, critical care physicians and nephrologists reviewing all available evidence in extracorporeal procedures for the treatment of intoxications in a standardized way to distill treatment recommendations for the physician at the bedside. The second round of guidelines will include recommendations for ethylenglycol intoxication. The case reported here is of a 60-year old man with a body weight of 65 kg who ingested approximately half a bottle (500 mL) of Aral Antifreeze in a suicidal attempt and presented around 12 h later with severe metabolic acidosis (venous blood gas analysis: pH 7.13; lactate 30 mmol/l, anion gap 23.3 mmol/l). As fomepizole, the inhibitor of the alcohol dehydrogenase, was not readily available, therapy with intermittent hemodialysis was started, as well as ethanol infusion. The first available ethylenglycol concentration before prolonged intermittent hemodialysis was 1230 mg/L. The total removed amount of ethylenglycol during intermittent hemodialysis, as well as following prolonged intermittent renal replacement therapy, was quantified (102 and 65 g). Based on this case report, the new EXRIP recommendations for the role of extracorporeal treatment in the case of ethylenglycol intoxication are discussed.

Delayed Treatment With 4-Methylpyrazole Protects Against Acetaminophen Hepatotoxicity in Mice by Inhibition of c-Jun n-Terminal Kinase

Acetaminophen (APAP) overdose is the most common cause of hepatotoxicity and acute liver failure in the United States and many western countries. However, the only clinically approved antidote, N-acetylcysteine, has a limited therapeutic window. 4-Methylpyrazole (4MP) is an antidote for methanol and ethylene glycol poisoning, and we have recently shown that cotreatment of 4MP with APAP effectively prevents toxicity by inhibiting Cyp2E1. To evaluate if 4MP can be used therapeutically, C57BL/6J mice were treated with 300 mg/kg APAP followed by 50 mg/kg 4MP 90 min later (after the metabolism phase). In these experiments, 4MP significantly attenuated liver injury at 3, 6, and 24 h after APAP as shown by 80%-90% reduction in plasma alanine aminotransferase activities and reduced areas of necrosis. 4MP prevented c-Jun c-Jun N-terminal kinase (JNK) activation and its mitochondrial translocation, and reduced mitochondrial oxidant stress and nuclear DNA fragmentation. 4MP also prevented JNK activation in other liver injury models. Molecular docking experiments showed that 4MP can bind to the ATP binding site of JNK. These data suggest that treatment with 4MP after the metabolism phase effectively prevents APAP-induced liver injury in the clinically relevant mouse model in vivo mainly through the inhibition of JNK activation. 4MP, a drug approved for human use, is as effective as N-acetylcysteine or can be even more effective in cases of severe overdoses with prolonged metabolism (600 mg/kg). 4MP acts on alternative therapeutic targets and thus may be a novel approach to treatment of APAP overdose in patients that complements N-acetylcysteine.

Data on the relationship between acetone, ethylene glycol, isopropanol, methanol, and propylene glycol serum/plasma concentrations and osmolal gaps in patients at an academic medical center

Ingestion of toxic alcohols other than ethanol (ethylene glycol, methanol, isopropanol, and propylene glycol) can cause life-threatening complications including altered level of consciousness, respiratory depression, and organ damage from metabolites. Many hospitals lack the ability to specifically analyze these compounds using gas chromatography, gas chromatography/mass spectrometry, or by enzymatic assays for ethylene glycol. Consequently, the presence of these compounds in blood is often ascertained indirectly by laboratory testing for acid-base status, osmolal gap, and anion gap. In the related research article, we analyzed 260 samples originating from 158 unique patients that had osmolal gap and specific testing for toxic alcohols performed on serum/plasma at an academic medical center central clinical laboratory. The data in this article provide the patient demographic, osmolal gap (and associated laboratory tests needed for this calculation), ethanol concentration by enzymatic assay, specific testing for toxic alcohols (ethylene glycol, isopropanol, methanol, propylene glycol) and acetone, anion gap, clinical history, antidotal treatment, and estimated timing of ingestion. The analyzed data is provided in the supplementary tables included in this article. Bias plots of osmolal gap estimations are included in a figure. The dataset reported is related to the research article entitled "Correlation of Osmolal Gap with Measured Concentrations of Acetone, Ethylene Glycol, Isopropanol, Methanol, and Propylene Glycol in Patients at an Academic Medical Center" [1].

Educational Case: Ethylene Glycol Poisoning

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040.¹

Correlation of osmolal gap with measured concentrations of acetone, ethylene glycol, isopropanol, methanol, and propylene glycol in patients at an academic medical center

The ingestion of toxic alcohols including methanol, ethylene glycol, and isopropanol remains a significant public health problem. These compounds can cause central nervous system depression and, for methanol and ethylene glycol, organ damage from toxic metabolites. The presence of these compounds in serum/plasma can often be determined and monitored by measuring the osmolal gap (OG). However, other compounds originating from endogenous or exogenous sources, such as propylene glycol and acetone, can also increase the OG. Conversion factors can be used to estimate specific concentrations of acetone and toxic alcohols from OG. In this retrospective study, data were analyzed for 260 samples originating from 158 unique patients that had determination of both OG and concentrations for toxic alcohols at an academic medical center central laboratory. Specific analysis included gas chromatography (acetone, isopropanol, methanol, ethylene glycol, propylene glycol) and/or enzymatic assay (ethylene glycol). Many samples also contained ethanol. The data was grouped by type of ingestion. The present study analyzed the relationship between the OG calculated from measured plasma/serum osmolality and the OG estimated by applying conversion factors to measured concentrations of the different compounds. The correlations tend to be linear and vary by compound, with methanol and ethylene glycol having the highest R2 values of 0.93 and 0.95, respectively, consistent with other published studies. Higher variability was seen for the data for isopropanol and acetone. For each of the data subsets, the estimated toxic alcohol concentration calculated using conversion factors from OG tends to overestimate the actual concentration of the compound. Overall, the present study demonstrates the generally linear relationship between OG determined by osmolality and the OG estimated using measured concentrations of acetone and toxic alcohols.

Acute toxic kidney injury

Substances toxic to the kidney are legion in the modern world. The sheer number and variety, their mutual interactions and, metabolism within the body are a challenge to research. Moreover, the kidney is especially prone to injury owing to its physiology. Acute kidney injury (AKI) induced by poisonous or primarily nephrotoxic substances, may be community acquired with ingestion or inhalation or nosocomial. Many nephrotoxic plants, animal poisons, medications, chemicals and illicit drugs can induce AKI by varying pathophysiological pathways. Moreover, the epidemiology of toxic AKI varies depending on country, regions within countries, socioeconomic status and health care facilities. In this review, we have selected nephrotoxic insults due to medication, plants, animal including snake venom toxicity, environmental, (agri)chemicals and also illicit drugs. We conclude with a section on diagnosis, clinical presentation and management of poisoning accompanied by various organ dysfunction and AKI.

Extracorporeal Removal of Poisons and Toxins

Extracorporeal therapies have been used to remove toxins from the body for over 50 years and have a greater role than ever before in the treatment of poisonings. Improvements in technology have resulted in increased efficacy of removing drugs and other toxins with hemodialysis, and newer extracorporeal therapy modalities have expanded the role of extracorporeal supportive care of poisoned patients. However, despite these changes, for at least the past three decades the most frequently dialyzed poisons remain salicylates, toxic alcohols, and lithium; in addition, the extracorporeal treatment of choice for therapeutic removal of nearly all poisonings remains intermittent hemodialysis. For the clinician, consideration of extracorporeal therapy in the treatment of a poisoning depends upon the characteristics of toxins amenable to extracorporeal removal (e.g., molecular mass, volume of distribution, protein binding), choice of extracorporeal treatment modality for a given poisoning, and when the benefit of the procedure justifies additive risk. Given the relative rarity of poisonings treated with extracorporeal therapies, the level of evidence for extracorporeal treatment of poisoning is not robust; however, extracorporeal treatment of a number of individual toxins have been systematically reviewed within the current decade by the Extracorporeal Treatment in Poisoning workgroup, which has published treatment recommendations with an improved evidence base. Some of these recommendations are discussed, as well as management of a small number of relevant poisonings where extracorporeal therapy use may be considered.

Rising above helium: A hydrogen carrier gas chromatography flame ionization detection (GC-FID) method for the simultaneous quantification of toxic alcohols and ethylene glycol in human plasma specimens

Here we validate a GC, Flame Ionization Detection (GC-FID), liquid injection method using hydrogen as a carrier gas combining analysis of toxic volatile alcohols (VA): methanol, ethanol, isopropanol, acetone, as well as glycols, ethylene glycol (EG) and propylene glycol (PG), in a single method.

METHODOLOGY

200 μL of calibrator, QC, or patient specimen were deproteinized with 400 μL of acetonitrile containing internal standards (10 mmol/L N-propyl alcohol for VA and 2.5 mmol/L 1,2-butanediol for glycols). GC-FID analysis using hydrogen carrier gas and nitrogen makeup gas utilized an Agilent 7890 system equipped with Agilent 7683 liquid autosampler on a 30 m × 530 μm RTX-200 fused silica column. Method validation included repeatability, recovery, carryover, linearity, lower limit of quantification (LLOQ), accuracy, selectivity and measurement uncertainty.

RESULTS

The 8.3 min from injection to injection reduced time of analysis by 45% over a previously reported method using Helium carrier gas with no loss in resolution. Within-run and Between-run variability were ≤1.4% and ≤6.8% respectively. Recovery was 100% within a 95% confidence interval. Carryover was negligible for all but EG. LLOQ was <1 mmol/L for all analytes. The upper range of linearity was 120 mmol/L for methanol, ethanol and isopropanol, 100 mmol/L for acetone and 50 mmol/L for EG. Analytes demonstrated acceptable accuracy and measurement uncertainty using College of American Pathologists (CAP) criteria. Toluene can cause a false positive EG, while benzene, xylene and 1,3 butanediol can cause false negative EG.

CONCLUSIONS

Converting from Helium to Hydrogen carrier gas benefits patient care through a reduction in turnaround time and provides a cost savings to the laboratory.

Ethylene glycol intoxication following brake fluid ingestion complicated with unilateral facial nerve palsy: a case report

Background

Brake oil is an automobile transmission fluid composed of a mixture of toxic alcohols such as ethylene glycols and glycol ethers. Both accidental and intentional ingestion cases have been reported and they can present with multisystem involvement. Life-threatening complications evolve from deleterious effects on cardiopulmonary and renal systems. Effects on neurological and gastrointestinal systems give rise to a multitude of complications although non-fatal in nature. The biochemical panel consists of a high concentration of ethylene glycol with severe metabolic acidosis, high anion gap, high osmolar gap, oxaluria, and hypocalcemia. The mainstay of treatment is enhanced elimination of ethylene glycol and its metabolites by hemodialysis, together with general supportive care, gastric decontamination, and vitamins such as thiamine and pyridoxine to minimize the adverse effects of intoxication.

Case presentation

A 26-year-old Sinhalese woman presented with reduced urine output, shortness of breath, reduced level of consciousness, abdominal pain, and vomiting with mild degree fever of 2 days’ duration. She had bilateral lower limb edema, crepitations over bilateral lower lung fields, and right-sided lower motor type facial nerve palsy. Investigations showed severe metabolic acidosis with high anion gap and high osmolar gap. With regular hemodialysis she made a complete recovery after 3 months.

Conclusion

Even without a clear history of poisoning, the presence of a high anion, high osmolar gap metabolic acidosis should prompt one to search for ethylene glycol ingestion. Uncommon manifestations like cranial neuropathies need to be examined and considered. Timely aggressive treatment leads to a better prognosis.

Treatment of Ethylene Glycol Poisoning with Oral Ethyl Alcohol

Ethylene glycol poisoning is not uncommon in India. The ill effects are primarily caused by its toxic metabolites: glycolic acid and oxalic acid. A 70-year-old female presented to our hospital with ataxia after ingestion of ethylene glycol. The reported case describes the management of ethylene glycol poisoning using oral ethyl alcohol as an alternative to the recommended intravenous ethyl alcohol and fomepizole that are not available for use in India. The need for high degree of clinical suspicion, targeted investigations, and early instigation of treatment is of prime importance in cases of ethylene glycol poisoning as it can lead to long-term complications or even death.

Synthesis, biological evaluation and molecular docking of novel pyrazole derivatives as potent carbonic anhydrase and acetylcholinesterase inhibitors

A series of substituted pyrazole compounds (1-8 and 9a, b) were synthesized and their structure was characterized by IR, NMR, and Mass analysis. These obtained novel pyrazole derivatives (1-8 and 9a, b) were emerged as effective inhibitors of the cytosolic carbonic anhydrase I and II isoforms (hCA I and II) and acetylcholinesterase (AChE) enzymes with K_i values in the range of 1.03 ± 0.23-22.65 ± 5.36 µM for hCA I, 1.82 ± 0.30-27.94 ± 4.74 µM for hCA II, and 48.94 ± 9.63-116.05 ± 14.95 µM for AChE, respectively. Docking studies were performed for the most active compounds, 2 and 5, and binding mode between the compounds and the receptors were determined.

Targeting Metalloenzymes for Therapeutic Intervention

Metalloenzymes are central to a wide range of essential biological activities, including nucleic acid modification, protein degradation, and many others. The role of metalloenzymes in these processes also makes them central for the progression of many diseases and, as such, makes metalloenzymes attractive targets for therapeutic intervention. Increasing awareness of the role metalloenzymes play in disease and their importance as a class of targets has amplified interest in the development of new strategies to develop inhibitors and ultimately useful drugs. In this Review, we provide a broad overview of several drug discovery efforts focused on metalloenzymes and attempt to map out the current landscape of high-value metalloenzyme targets.

Extracorporeal Treatment in the Management of Acute Poisoning: What an Intensivist Should Know?

Extracorporeal treatment (ECTR) represents a treatment modality promoting removal of endogenous or exogenous poisons and supporting or temporarily replacing a vital organ. This article aims to provide a brief overview of the technical aspects and the potential indications and limitations of the different ECTRs, highlighting the important characteristics of poison amenable to ECTR and the most appropriate prescriptions used in the setting of acute poisoning. The various principles that govern poison elimination by ECTR (diffusion, convection, adsorption, and centrifugation) and how components of the ECTR can be adjusted to maximize clearance have also being discussed.

Antidotes in Poisoning

Introduction

Antidotes are agents that negate the effect of a poison or toxin. Antidotes mediate its effect either by preventing the absorption of the toxin, by binding and neutralizing the poison, antagonizing its end-organ effect, or by inhibition of conversion of the toxin to more toxic metabolites. Antidote administration may not only result in the reduction of free or active toxin level, but also in the mitigation of end-organ effects of the toxin by mechanisms that include competitive inhibition, receptor blockade or direct antagonism of the toxin.

Mechanism of action of antidotes

Reduction in free toxin level can be achieved by specific and non-specific agents that bind to the toxin. The most commonly used non-specific binding agent is activated charcoal. Specific binders include chelating agents, bioscavenger therapy and immunotherapy. In some situations, enhanced elimination can be achieved by urinary alkalization or hemadsorption. Competitive inhibition of enzymes (e.g. ethanol for methanol poisoning), enhancement of enzyme function (e.g. oximes for organophosphorus poisoning) and competitive receptor blockade (e.g. naloxone, flumazenil) are other mechanisms by which antidotes act. Drugs such as N-acetyl cysteine and sodium thiocyanate reduce the formation of toxic metabolites in paracetamol and cyanide poisoning respectively. Drugs such as atropine and magnesium are used to counteract the end-organ effects in organophosphorus poisoning. Vitamins such as vitamin K, folic acid and pyridoxine are used to antagonise the effects of warfarin, methotrexate and INH respectively in the setting of toxicity or overdose. This review provides an overview of the role of antidotes in poisoning.

How to cite this article

Chacko B, Peter JV. Antidotes in Poisoning. Indian J Crit Care Med 2019;23(Suppl 4):S241-S249.

[A Sweet Drink with Consequences]

A Sweet Drink with Consequences Abstract. Intoxications with ethylene glycol are rare, however, small quantities from the substance can be life-threatening. Regarding the treatment it is important to recognize the intoxication quickly and to immediately start the appropriate treatment. Intoxications with ethylene glycol or with methanol should always be considered as differential diagnosis in patients with severe metabolic acidosis. It is also very important to calculate the osmolal gap.

Outcomes after toxic alcohol poisoning: a systematic review protocol

BACKGROUND

Toxic alcohols have been implicated in accidental ingestions and intentional exposures. Recognition of toxic alcohol poisoning is challenging. The main treatment modalities include antidotes with alcohol dehydrogenase inhibitors and dialysis. Current guidelines exist for both methanol and ethylene glycol intoxication. However, treatment consensus related to other toxic alcohols is limited. Furthermore, uncertainties regarding thresholds for when to initiate antidotes and dialysis persist. As a consequence, variations exist in the interventions utilized for management of all toxic alcohol poisonings. To our knowledge, no prior systematic review of clinical outcomes of toxic alcohols exists. The objective of this study is to summarize existing evidence on short- and long-term outcomes of patients following toxic alcohol poisonings, including methanol, ethylene glycol, isopropanol, propylene glycol, and diethylene glycol.

METHODS

A literature search in PubMed, MEDLINE, and EMBASE will be performed based on pre-determined criteria. There will be no restrictions on publication dates or languages. The search will be supplemented by manual scan of bibliographies of eligible studies and gray literature assessment. Observational studies and clinical trials will be included in this review. Once eligible studies have been selected based on pre-specified criteria, two investigators will extract relevant data independently and perform quality assessment per validated tools. A pooled analysis of mortality and short- and long-term secondary outcomes will be performed. Pre-specified subgroup analyses will be performed according to the type of toxic alcohol intoxication, mode of renal replacement therapy, and medical interventions received. A meta-analysis will be performed if three or more studies with similar populations, type of toxic alcohol poisoning, and outcome measures, as well as adequate quality, are identified. This review will be reported according to the recommendations of the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) Statement.

DISCUSSION

This systematic review aims to synthesize current evidence in the short- and long-term outcomes of post-toxic alcohol poisoning. The results will enhance the understanding of patient morbidity and mortality after toxic alcohol poisoning, help inform uniform concrete management guideline development, identify gaps in the current state of knowledge, and provide evidence to help implement post-treatment follow-up.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42018101955.

Toxic Effects of Methanol among Illegally Dispatched Workers at Aluminum CNC Cutting Process in Small-Scale, Third-Tier Subcontractor Factories of Smartphone Manufacturers in the Republic of Korea

An outbreak of occupational methanol poisoning occurred in small-scale, third-tier factories of large-scale smartphone manufacturers in the Republic of Korea in 2016. To investigate the working environment and the health effects of methanol exposure among co-workers in the methanol poisoning cases, we performed a cross-sectional study on 155 workers at five aluminum Computerized Numerical Control (CNC) cutting factories. Gas chromatography measured air and urinary methanol concentration. In the medical examination, symptom surveys, ophthalmological examinations, and neurobehavioral tests were done. Multiple logistic regression analyses controlling for age and sex were conducted to reveal the association of employment duration with symptoms. Air concentrations of methanol in factory A and E ranged from 228.5 to 2220.0 ppm. Mean urinary methanol concentrations of the workers in each factory were from 3.5 mg/L up to 91.2 mg/L. The odds ratios for symptoms of deteriorating vision and central nervous system (CNS) increased according to the employment duration after adjusting for age and sex. Four cases with an injured optic nerve and two cases with decreased neurobehavioral function were founded among co-workers of the victims. This study showed that the methanol exposure under poor environmental control not only produces eye and CNS symptoms but also affects neurobehavioral function and the optic nerve. The role of subcontracting production and dispatched work under poor environmental control was discussed.

4-Methylpyrazole protects against acetaminophen hepatotoxicity in mice and in primary human hepatocytes

Liver injury due to acetaminophen (APAP) overdose is the major cause of acute liver failure in the United States. While treatment with N-acetylcysteine is the current standard of care for APAP overdose, anecdotal evidence suggests that administration of 4-methylpyrazole (4MP) may be beneficial in the clinic. The objective of the current study was to examine the protective effect of 4MP and its mechanism of action. Male C57BL/6J mice were co-treated with 300 mg/kg of APAP and 50 mg/kg of 4MP. The severe liver injury induced by APAP at 6 h as indicated by elevated plasma alanine aminotransferase activities, centrilobular necrosis, and nuclear DNA fragmentation was almost completely eliminated by 4MP. In addition, 4MP largely prevented APAP-induced activation of c-Jun N-terminal kinase (JNK), mitochondrial translocation of phospho-JNK and Bax, and the release of mitochondrial intermembrane proteins. Importantly, 4MP inhibited the generation of APAP protein adducts and formation of APAP-glutathione (GSH) conjugates and attenuated the depletion of the hepatic GSH content. These findings are relevant to humans because 4MP also prevented APAP-induced cell death in primary human hepatocytes. In conclusion, early treatment with 4MP can completely prevent liver injury after APAP overdose by inhibiting cytochrome P450 and preventing generation of the reactive metabolite.

PEG 3350 Administration Is Not Associated with Sustained Elevation of Glycol Levels

OBJECTIVE

To determine whether trace amounts of ethylene glycol (EG), diethylene glycol (DEG), or triethylene glycol (TEG) in PEG 3350 are associated with increased blood levels of EG, DEG, or TEG in children receiving daily PEG 3350 therapy.

STUDY DESIGN

Blood samples were drawn from 9 children who were being treated for constipation with PEG 3350 (6-12 years old) before and every 30 minutes for 3 hours after receiving 17 g of PEG 3350. PEG 3350, tap water, and blood samples from 18 age- and sex-matched controls also were analyzed.

RESULTS

Baseline blood levels of EG and TEG did not differ between control and treated groups. DEG levels (median [IQR]) were lower in the PEG 3350 group (40.13 ng/mL [36.69, 63.94] vs 92.83 ng/mL [51.06, 128.93], P = .008). After PEG 3350 dose, levels of EG (390.51 ng/mL [326.06, 624.55]) and TEG (2.21 ng/mL [0, 4.5]) peaked at 90 minutes at 1032.81 ng/mL (826.84, 1486.13) (P = .009) and 35.17 ng/mL (15.81, 45.13) (P = .0005), respectively. DEG levels did not significantly change. Standard 17-g doses of PEG 3350 in 8 oz (237 mL) of water resulted in concentrations (mean ± SD) of EG, DEG, and TEG of 1.32 ± 0.23 µg/mL, 0.18 ± 0.03 µg/mL, and 0.12 ± 0.01 µg/mL, respectively. EG, DEG, and TEG levels in public water supply were 0.07 µg/mL, 0.21 µg/mL, and 0.02 µg/mL, respectively.

CONCLUSIONS

Daily PEG 3350 therapy in children was not associated with sustained elevation of EG, DEG, or TEG blood levels over levels in matched controls. Although EG and TEG levels increased after a standard dose of PEG 3350, their peak values remained well below toxic levels.

Lactate gap as a tool in identifying ethylene glycol poisoning

Ethylene glycol toxicity is a known cause of anion gap metabolic acidosis, with the presence of an osmolar gap and the right clinical context suggesting to the diagnosis. Rapid recognition and early treatment is crucial. Unfortunately, ethylene glycol levels are not readily available and must be performed at a reference laboratory. We present a case where recognising the significance of the 'lactate gap' assisted in identifying ethylene glycol poisoning.

Electroconvulsive Therapy in a Patient With a Recent Subarachnoid Hemorrhage

The safety of electroconvulsive therapy (ECT) is improving with advances in anesthesia and ECT technique. There are published case reports of successful treatment of depression in patients who were once considered at high medical risk. Recent cerebral hemorrhage is one of the conditions considered to significantly increase the risk of ECT treatment. Literature search did not indicate any case reports of ECT treatment in patients with recent subarachnoid hemorrhage. We report the successful ECT treatment of depression in an older man who had developed a subarachnoid hemorrhage after a suicide attempt by ingestion of antifreeze.

[CME: Ethylene Glycol Intoxication]

CME: Ethylene Glycol Intoxication Abstract. Ethylene glycol is a sweet-tasting alcohol used in common antifreeze and other industrial solutions. Without appropriate therapy, intoxication with ethylene glycol can result in severe metabolic acidosis, acute renal failure, and in death. After gastrointestinal resorption, hepatic metabolism starts with oxidation by alcohol dehydrogenase and results in severe anion gap metabolic acidosis. Other metabolic products are calcium oxalate crystals, which can deposit in several tissues like the kidneys and lead to acute tubular necrosis with reversible renal failure. The crucial therapeutic step is rapid inhibition of alcohol dehydrogenase with fomepizole or ethanol to avoid the formation of toxic metabolites. Additionally, haemodialysis is the most effective way to eliminate ethylene glycol as well as its toxic metabolites. If therapy is initiated rapidly, prognosis is favorable.

Use of a Rapid Ethylene Glycol Assay: a 4-Year Retrospective Study at an Academic Medical Center

Ethylene glycol (EG) is a common cause of toxic ingestions. Gas chromatography (GC)-based laboratory assays are the gold standard for diagnosing EG intoxication. However, GC requires specialized instrumentation and technical expertise that limits feasibility for many clinical laboratories. The objective of this retrospective study was to determine the utility of incorporating a rapid EG assay for management of cases with suspected EG poisoning. The University of Iowa Hospitals and Clinics core clinical laboratory adapted a veterinary EG assay (Catachem, Inc.) for the Roche Diagnostics cobas 8000 c502 analyzer and incorporated this assay in an osmolal gap-based algorithm for potential toxic alcohol/glycol ingestions. The main limitation is that high concentrations of propylene glycol (PG), while readily identifiable by reaction rate kinetics, can interfere with EG measurement. The clinical laboratory had the ability to perform GC for EG and PG, if needed. A total of 222 rapid EG and 24 EG/PG GC analyses were documented in 106 patient encounters. Of ten confirmed EG ingestions, eight cases were managed entirely with the rapid EG assay. PG interference was evident in 25 samples, leading to 8 GC analyses to rule out the presence of EG. Chart review of cases with negative rapid EG assay results showed no evidence of false negatives. The results of this study highlight the use of incorporating a rapid EG assay for the diagnosis and management of suspected EG toxicity by decreasing the reliance on GC. Future improvements would involve rapid EG assays that completely avoid interference by PG.