Can endogenous ethylene glycol production occur in humans? A detailed investigation of adult monozygotic twin sisters.

INTRODUCTION: To the best of our knowledge, clinically significant endogenous ethylene glycol production has never been reported in humans, very seldom reported in other animals or microorganisms, and then only under rare and specific conditions. We describe the detailed investigations we undertook in two adult monozygotic twin sisters to ascertain whether they were producing endogenous ethylene glycol. METHODS: Two previously healthy monozygotic adult twin sisters presented with recurrent episodes of apparent ethylene glycol poisoning beginning at age 35, requiring chronic hemodialysis to remove ethylene glycol and its metabolites as well as to restore metabolic homeostasis. The sisters denied ingestion or exposure to ethylene glycol. At their request, they were admitted to hospital under strict supervision to exclude surreptitious ingestion of ethylene glycol and to evaluate the need for treatment. Hemodialysis was withheld during this prospective study. Twin A was admitted for 14 days and twin B for 11 days. Serial biochemical analyses were performed in blood and urine. Clinical exome sequencing and mitochondrial deoxyribonucleic acid sequencing were also completed. RESULTS: In both twins, ethylene glycol was detected in urine, along with intermittent increases in concentrations of lactate, glycolate, and glycine in blood and/or urine. Blood ethylene glycol concentrations, however, remained <62 mg/L (<1 mmol/L) but became positive soon after discharge. The oxalate concentration remained normal in blood and urine. Plasma and urine amino acid profiles showed intermittent small increases in glycine, serine, taurine, proline, and/or alanine concentrations. Exome sequencing and mitochondrial deoxyribonucleic acid sequencing were non-diagnostic. Neither twin has been admitted with metabolic acidosis nor ethylene glycol poisoning since chronic hemodialysis was started. Twin A developed a calcium oxalate dihydrate lithiasis. DISCUSSION: Mitochondrial disease, methylmalonic/propionic/isovaleric aciduria, primary hyperoxaluria, and analyte error were all excluded in these twins, as were obvious common environmental exposures. CONCLUSION: Detailed investigations were performed in adult monozygotic twin sisters to ascertain whether they were producing endogenous ethylene glycol. Alternative explanations were excluded to the very best of our efforts and knowledge. Global metabolomics, gut microbiome analyses, and whole genome sequencing are pending.

Antidotes for poisoning by alcohols that form toxic metabolites.

The alcohols methanol, ethylene glycol and diethylene glycol share many characteristics. The most important is that the compounds themselves are relatively nontoxic but are metabolized, initially by alcohol dehydrogenase, to various toxic intermediates. These compounds are readily available worldwide in commercial products as well as in homemade alcoholic beverages, both of which lead to most of the poisonings, from either unintentional or intentional ingestion. Although relatively infrequent, toxic alcohol poisonings do unfortunately occur in outbreaks and can result in severe morbidity and mortality. These poisonings have traditionally been treated with ethanol since it competes for the active site of alcohol dehydrogenase and decreases the formation of toxic metabolites. Although ethanol can be an effective antidote, there are substantial practical problems with its use. Therefore fomepizole, a potent competitive inhibitor of alcohol dehydrogenase, was developed for a hopefully better treatment for metabolically toxic alcohol poisonings. Fomepizole has few side effects and is easy to use in practice and it may obviate the need for haemodialysis in some, but not all, patients. Hence, fomepizole has largely replaced ethanol as the toxic alcohol antidote in many countries. Nevertheless, ethanol remains an important alternative because access to fomepizole can be limited, the cost may appear excessive or the physician may prefer ethanol due to experience.

Clinical effects of cannabis compared to synthetic cannabinoid receptor agonists (SCRAs): a retrospective cohort study of presentations with acute toxicity to European hospitals between 2013 and 2020.

INTRODUCTION: Cannabis is the most common recreational drug worldwide and synthetic cannabinoid receptor agonists are currently the largest group of new psychoactive substances. The aim of this study was to compare the clinical features and outcomes of lone acute cannabis toxicity with lone acute synthetic cannabinoid receptor agonist toxicity in a large series of presentations to European emergency departments between 2013-2020. METHODS: Self-reported drug exposure, clinical, and outcome data were extracted from the European Drug Emergencies Network Plus which is a surveillance network that records data on drug-related emergency department presentations to 36 centres in 24 European countries. Cannabis exposure was considered the control in all analyses. To compare the lone cannabis and lone synthetic cannabinoid receptor agonist groups, univariate analysis using chi squared testing was used for categorical variables and non-parametric Mann-Whitney U- testing for continuous variables. Statistical significance was defined as a P value of <0.05. RESULTS: Between 2013-2020 there were 54,314 drug related presentations of which 2,657 were lone cannabis exposures and 503 lone synthetic cannabinoid receptor agonist exposures. Synthetic cannabinoid receptor agonist presentations had statistically significantly higher rates of drowsiness, coma, agitation, seizures and bradycardia at the time of presentation. Cannabis presentations were significantly more likely to have palpitations, chest pain, hypertension, tachycardia, anxiety, vomiting and headache. DISCUSSION: Emergency department presentations involving lone synthetic cannabinoid receptor agonist exposures were more likely to have neuropsychiatric features and be admitted to a psychiatric ward, and lone cannabis exposures were more likely to have cardiovascular features. Previous studies have shown variability in the acute toxicity of synthetic cannabinoid receptor agonists compared with cannabis but there is little comparative data available on lone exposures. There is limited direct comparison in the current literature between lone synthetic cannabinoid receptor agonist and lone cannabis exposure, with only two previous poison centre series and two clinical series. Whilst this study is limited by self-report being used to identify the drug(s) involved in the presentations, previous studies have demonstrated that self-report is reliable in emergency department presentations with acute drug toxicity. CONCLUSION: This study directly compares presentations with acute drug toxicity related to the lone use of cannabis or synthetic cannabinoid receptor agonists. It supports previous findings of increased neuropsychiatric toxicity from synthetic cannabinoid receptor agonists compared to cannabis and provides further data on cardiovascular toxicity in lone cannabis use.

Self-discharge during treatment for acute recreational drug toxicity: an observational study from emergency departments in seven European countries.

BACKGROUND: Self-discharge is a risk factor for readmission and excess mortality. We assess the rate of self-discharge from the emergency department (ED) among presentations for acute recreational drug toxicity and identify factors associated with self-discharge. METHODS: From the Euro-DEN Plus database of presentations to the ED with acute recreational drug toxicity, we extracted data from 11 centres in seven European countries from 2014 to 2017. Self-discharge was defined as taking one's own discharge or escaping from the ED before being medically cleared. We used multiple logistic regression analyses to look for factors associated with self-discharge. RESULTS: Among 15,135 included presentations, 1807 (11.9%) self-discharged. Self-discharge rates varied from 1.7 to 17.1% between centres. Synthetic cannabinoids were associated with self-discharge, adjusted odds ratio 1.44 (95% confidence interval 1.10-1.89), as were heroin, 1.44 (1.26-1.64), agitation, 1.27 (1.10-1.46), and naloxone treatment, 1.27 (1.07-1.51), while sedation protected from self-discharge, 0.38 (0.30-0.48). CONCLUSION: One in eight presentations self-discharged. There was a large variation in self-discharge rates across the participating centres, possibly partly reflecting different discharge procedures and practices. Measures to improve the management of agitation and cautious administration of naloxone to avoid opioid withdrawal symptoms may be approaches worth exploring to reduce self-discharge.

Determinants of Admission to Critical Care Following Acute Recreational Drug Toxicity: A Euro-DEN Plus Study.

This study aimed to characterize patients admitted to critical care following Emergency Department (ED) presentation with acute recreational drug toxicity and to identify determinants of admission to critical care. A retrospective multicenter matched case-control study was conducted by the European Drug Emergency Network Plus (Euro-DEN Plus) over the period 2014-2021. The cases were ED presentations with acute recreational drug toxicity admitted to critical care, the controls consisted of ED presentations with acute recreational drug toxicity medically discharged directly from the ED. The potential determinants of admission to critical care were assessed through multivariable conditional stepwise logistic regression analysis and multiple imputation was used to account for the missing data. From 2014 to 2021, 3448 Euro-DEN Plus presentations involved patients admitted to critical care (76.9% males; mean age 33.2 years; SD 10.9 years). Patient age ≥35 years (as compared to ≤18 years) was a determinant of admission to critical care following acute recreational drug toxicity (adjusted odds ratio, aOR, 1.51, 95% confidence interval, CI, 1.15-1.99), along with polydrug use (aOR 1.39, 95% CI 1.22-1.59), ethanol co-ingestion (aOR 1.44, 95% CI 1.26-1.64), and the use of gamma-hydroxybutyrate/gamma-butyrolactone (GHB/GBL, aOR 3.08, 95% CI 2.66-3.57). Conversely, lower odds of admission to critical care were associated with the use of cocaine (aOR 0.85, 95% CI 0.74-0.99), cannabis (aOR 0.44, 95% CI 0.37-0.52), heroin (aOR 0.80, 95% CI 0.69-0.93), and amphetamine (aOR 0.65, 95% CI 0.54-0.78), as was the arrival to the ED during the night (8 p.m.-8 a.m., aOR 0.88, 95% CI 0.79-0.98). These findings, which deserve confirmation and further investigation, could contribute to a more complete understanding of the decision-making process underlying the admission to critical care of patients with acute recreational drug toxicity.

Severity of emergency department presentations due to acute drug toxicity in Europe: a longitudinal analysis over a 6-year period (2014-2019) stratified by sex.

OBJECTIVE: To investigate whether the severity of acute recreation drug toxicity presentations to emergency departments (EDs) in Europe has changed in recent years and to uncover potential sex differences. DESIGN: We analysed presentations to 36 EDs in 24 European countries relating to acute recreational drug toxicity, with separate analysis for presentations involving lone use of cannabis, cocaine, and heroin. As severity markers, we calculated rates of hospitalization, admission to ICU, intubation, and death by annual quarters between 2014 and 2019. Trends on severity over time were estimated by logistic regression. Differences between men and women were assessed by interaction. Sensitivity analysis was performed including only EDs that provided data for all 24 quarters. Analyses of intoxications taken altogether were adjusted by age and sex, while of lone intoxications being also adjusted by ethanol co-ingestion. RESULTS: There were 43 633 presentations (median age = 31 years, interquartile range = 25-40 years, men = 76.5%) resulting in 10 344 hospitalizations (23.9%), 2568 ICU admissions (5.9%), 1391 intubations (3.2%), and 171 deaths (0.39%). Hospitalization, ICU admission and death did not differ by sex, but intubation was more frequent in men (3.4% vs. 2.3%, P < 0.001). No significant changes in the severity of drug intoxications over time were found when considered altogether, neither for lone cannabis (n = 4264) nor cocaine (n = 3562). Conversely, significant increases in hospitalization [odds ratios (OR) = 1.023, 95% confidence interval (CI) = 1.004-1.041], ICU admission (OR = 1.080, 95% CI = 1.042-1.118) and in intubation (OR = 1.049, 95% CI = 1.001-1.099) were detected for lone heroin presentations (n = 1997). Sensitivity analysis (32 245 presentations, 14 EDs, 9 countries) confirmed the overall absence of changes in severity markers (except for death rate, which significantly decreased by quarter: OR = 0.968, 95% CI = 0.943-0.994). Additionally, it suggested an increased risk over time of intubation for cocaine (OR = 1.068, 95% CI = 1.009-1.130) and confirmed the increased risk of ICU admission for heroin (OR = 1.058, 95% CI = 1.013-1.105). Changes in severity over time did not differ according to sex in the main analysis of the whole cohort, while a significantly higher decrease in risk of death in men was found in the sensitivity analysis (OR = 0.894, 95% CI = 0.825-969 vs. OR = 0.949, 95% CI = 0.860-1.048; P interaction = 0.042). CONCLUSIONS: The severity of presentations to European EDs remained mainly unchanged during 2014-2019, but the risk of death may have decreased. Conversely, intubation in lone cocaine and ICU admission in lone heroin intoxications have increased. Although men and women exhibited a similar pattern over the period for the majority of comparisons, our data suggest that women exhibited a smaller decrease of the overall risk of death.

An enzymatic assay with formate oxidase for point-of-care diagnosis of methanol poisoning.

Gas chromatographic analysis for quantification of plasma methanol requires laboratory equipment and personnel, and it is typically unavailable in short time notice, especially in low- and middle-income countries. Detection of formate with the enzyme formate oxidase (FOX) is a promising method that can make the diagnosis of methanol poisoning simple and fast. The aims of this study were to test the sensitivity and specificity of a modified FOX-enzyme and to test the specificity of a point-of-care (POC)-model containing FOX-enzyme with samples from patients with metabolic acidosis. The sensitivity and specificity of FOX-enzyme in aqueous solution were evaluated with a spectrometer and by visual detection for colour change. Formate concentrations between 1 and 20 mmol/L were used to test sensitivity, and 18 potentially interfering substances were tested for specificity. The sensitivity of the FOX-enzyme was 100% and the specificity 97%. When specificity of the POC-model was tested, no false positives were detected. As such, the sensitivity and specificity of this modified FOX-enzyme for detection of formate were high. The results with this enzyme confirm the potential for its use in formate analysis as a fast diagnosis of methanol poisoning.

Poisoning with central stimulant drugs: an observational study from Oslo, Norway.

BACKGROUND: The use of central stimulant drugs causes significant morbidity. We describe poisonings with central stimulant drugs and compare the different central stimulants concerning combinations with other drugs, treatment, and clinical course.  METHODS: Patients presenting from 1 October 2013 to 31 March 2016 with poisoning related to the recreational use of central stimulant drugs were retrospectively included at a primary care emergency outpatient clinic and at a hospital emergency department in Oslo, Norway. Diagnosis of toxic agents was mainly based on the clinical assessment of the doctor treating the patient. Amphetamine and methamphetamine were co-categorized as amphetamine. RESULTS: Among the 1131 cases of acute poisoning with central stimulant drugs at the outpatient clinic, amphetamine was involved in 808 (71.4%), cocaine in 252 (22.3%) methylenedioxymethamphetamine (MDMA) in 104 (9.2%), and methylphenidate in 13 (1.1%). Among the 211 cases at the hospital, amphetamine was involved in 167 (79.1%), cocaine in 60 (28.4%), and MDMA in 38 (18.0%). Amphetamine was frequently combined with opioids (40.1% at the outpatient clinic and 41.9% at the hospital) and benzodiazepines (28.3% and 45.5%), while MDMA often was combined with ethanol (64.4% and 71.1%), as was cocaine (62.7% and 61.7%). Sedation was given in 5.2% and 38.4% of cases, naloxone in 9.4% and 37.0%, and flumazenil in 0.1% and 28.0%. In total, 16.5% of the cases at the outpatient clinic were transferred to a hospital for medical review and 8.5% to a psychiatric hospital. Among the hospital patients, 92.9% were admitted to intensive care. CONCLUSION: Amphetamine was the most common central stimulant drug involved in acute poisoning in Oslo, often combined with opioids and benzodiazepines.

A cross-sectional multicenter linkage study of hospital admissions and mortality due to methanol poisoning in Iranian adults during the COVID-19 pandemic.

A methanol poisoning outbreak occurred in Iran during the initial months of coronavirus disease 2019 (COVID-19) pandemic. We aimed to evaluate the epidemiology of the outbreak in terms of hospitalizations and deaths. A cross-sectional linkage study was conducted based on the hospitalization data collected from thirteen referral toxicology centers throughout Iran as well as mortality data obtained from the Iranian Legal Medicine Organization (LMO). Patient data were extracted for all cases aged > 19 years with toxic alcohol poisoning during the study period from February until June 2020. A total of 795 patients were hospitalized due to methanol poisoning, of whom 84 died. Median [interquartile ratio; IQR] age was 32 [26, 40] years (range 19-91 years). Patients had generally ingested alcohol for recreational motives (653, 82.1%) while 3.1% (n = 25) had consumed alcohol-based hand sanitizers to prevent or cure COVID-19 infection. Age was significantly lower in survivors than in non-survivors (P < 0.001) and in patients without sequelae vs. with sequelae (P = 0.026). Twenty non-survivors presented with a Glasgow Coma Scale (GCS) score > 8, six of whom were completely alert on presentation to the emergency departments. The time from alcohol ingestion to hospital admission was not significantly different between provinces. In East Azerbaijan province, where hemodialysis was started within on average 60 min of admission, the rate of sequelae was 11.4% (compared to 19.6% average of other provinces)-equivalent to a reduction of the odds of sequelae by 2.1 times [95% CI 1.2, 3.7; p = 0.009]. Older patients were more prone to fatal outcome and sequelae, including visual disturbances. Early arrival at the hospital can facilitate timely diagnosis and treatment and may reduce long-term morbidity from methanol poisoning. Our data thus suggest the importance of raising public awareness of the risks and early symptoms of methanol intoxication.

Peppermint protocol: first results for gas chromatography-ion mobility spectrometry.

ThePeppermint Initiativeseeks to inform the standardisation of breath analysis methods. FivePeppermint Experimentswith gas chromatography-ion mobility spectrometry (GC-IMS), operating in the positive mode with a tritium3H 5.68 keV, 370 MBq ionisation source, were undertaken to provide benchmarkPeppermint Washoutdata for this technique, to support its use in breath-testing, analysis, and research. Headspace analysis of a peppermint-oil capsule by GC-IMS with on-column injection (0.5 cm3) identified 12 IMS responsive compounds, of which the four most abundant were: eucalyptol;ß-pinene;α-pinene; and limonene. Elevated concentrations of these four compounds were identified in exhaled-breath following ingestion of a peppermint-oil capsule. An unidentified compound attributed as a volatile catabolite of peppermint-oil was also observed. The most intense exhaled peppermint-oil component was eucalyptol, which was selected as a peppermint marker for benchmarking GC-IMS. Twenty-five washout experiments monitored levels of exhaled eucalyptol, by GC-IMS with on-column injection (0.5 cm3), att= 0 min, and then att+ 60,t+ 90,t+ 165,t+ 285 andt+ 360 min from ingestion of a peppermint capsule resulting in 148 peppermint breath analyses. Additionally, thePeppermint Washoutdata was used to evaluate clinical deployments with a further five washout tests run in clinical settings generating an additional 35 breath samples. Regression analysis yielded an average extrapolated time taken for exhaled eucalyptol levels to return to baseline values to be 429 ± 62 min (±95% confidence-interval). The benchmark value was assigned to the lower 95% confidence-interval, 367 min. Further evaluation of the data indicated that the maximum number of volatile organic compounds discernible from a 0.5 cm3breath sample was 69, while the use of an in-line biofilter appeared to reduce this to 34.

Differences in clinical features associated with cannabis intoxication in presentations to European emergency departments according to patient age and sex.

OBJECTIVE: To investigate if clinical features associated with acute cannabis intoxication in patients presenting to Emergency Departments for medical assistance differ according to patient age and sex. METHODS: We analysed presentations in the Euro-DEN Plus dataset from 2014 to 2019 in which cannabis was the only drug involved (except for alcohol), and age, sex and alcohol co-ingestion had been recorded. Age was considered as categorical (five groups; <20, 20-29, 30-39, 40-49 and ≥50 years), and sex as binary variable (male/female). We evaluated 12 key clinical features recorded during emergency department (ED) care. Risks of presenting with each of these clinical features according to patient age and sex were calculated by logistic regression models, and adjusted for sex, age and alcohol co-ingestion. RESULTS: 4,268 of 43,633 Euro-DEN presentations (9.8%) fulfilled the inclusion criteria (median age: 26 years (IQR = 20-34), 70% male, 52% co-ingested alcohol). The frequency of clinical features was: anxiety 28%, vomiting 24%, agitation 23%, palpitations 14%, reduced consciousness 13%, acute psychosis 9%, hallucinations 9%, chest pain 7%, headache 6%, hypotension 4%, hypertension 3% and seizures 2%. Patients younger than 20 years more frequently had vomiting (34.7% of cases), reduced consciousness (21.5%), and headache (10.8%); and less frequently acute psychosis (5.5%). Patients older than 49 years more often had hypotension (6.5%) and less frequently vomiting (20%), anxiety (14%), agitation (14%) and reduced consciousness (10%). Males more frequently presented with hypertension (3.7 vs. 1.5%; OR = 2.311, 95%CI = 1.299-3.816), psychosis (10.4 vs 6.3%; 1.948, 1.432-2.430), chest pain (8.1 vs 4.5%; 1.838, 1.390-2.430) and seizures (2.5 vs 1.4%; 1.805, 1.065-3.060), and less frequently with vomiting (21.8 vs 28.2%; 0.793, 0.677-0.930), anxiety (25.4 vs 32.3%; 0.655, 0.561-0.766) and hypotension (2.9 vs 5.8%; 0.485, 0.350-0.671). CONCLUSIONS: The prevalence of some clinical features typically associated with acute cannabis intoxication differed according to age and sex. The causes for these differences should be further investigated in order to better understand the pathophysiology of cannabis-related acute toxicity, and they may be relevant particularly for developing prevention campaigns and for treatment in specific sex and/or age groups.

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.

The serum glycolate concentration: its prognostic value and its correlation to surrogate markers in ethylene glycol exposures.

CONTEXT: Ethylene glycol poisoning manifests as metabolic acidemia, acute kidney injury and death. The diagnosis and treatment depend on history and biochemical tests. Glycolate is a key toxic metabolite that impacts prognosis, but assay results are not widely available in a clinically useful timeframe. We quantitated the impact of serum glycolate concentration for prognostication and evaluated whether more readily available biochemical tests are acceptable surrogates for the glycolate concentration. OBJECTIVES: The objectives of this study are to 1) assess the prognostic value of the initial glycolate concentration on the occurrence of AKI or mortality in patients with ethylene glycol exposure (prognostic study); 2) identify surrogate markers that correlate best with glycolate concentrations (surrogate study). METHODS: A systematic review of the literature was performed using Medline/PubMed, EMBASE, Cochrane library, conference proceedings and reference lists. Human studies reporting measured glycolate concentrations were eligible. Glycolate concentrations were related to categorical clinical outcomes (acute kidney injury, mortality), and correlated with continuous surrogate biochemical measurements (anion gap, base excess, bicarbonate concentration and pH). Receiver operating characteristic curves were constructed to calculate the positive predictive values and the negative predictive values of the threshold glycolate concentrations that predict acute kidney injury and mortality. Further, glycolate concentrations corresponding to 100% negative predictive value for mortality and 95% negative predictive value for acute kidney injury were determined. RESULTS: Of 1,531 articles identified, 655 were potentially eligible and 32 were included, reflecting 137 cases from 133 patients for the prognostic study and 154 cases from 150 patients for the surrogate study. The median glycolate concentration was 11.2 mmol/L (85.1 mg/dL, range 0-38.0 mmol/L, 0-288.8 mg/dL), 93% of patients were treated with antidotes, 80% received extracorporeal treatments, 49% developed acute kidney injury and 13% died. The glycolate concentration best predicting acute kidney injury was 12.9 mmol/L (98.0 mg/dL, sensitivity 78.5%, specificity 88.1%, positive predictive value 86.4%, negative predictive value 80.9%). The glycolate concentration threshold for a 95% negative predictive value for acute kidney injury was 6.6 mmol/L (50.2 mg/dL, sensitivity 96.9%, specificity 62.7%). The glycolate concentration best predicting mortality was 19.6 mmol/L (149.0 mg/dL, sensitivity 61.1%, specificity 81.4%, positive predictive value 33.3%, negative predictive value 93.2%). The glycolate concentration threshold for a 100% negative predictive value for mortality was 8.3 mmol/L (63.1 mg/dL, sensitivity 100.0%, specificity 35.6%). The glycolate concentration correlated best with the anion gap (R2 = 0.73), followed by bicarbonate (R2 = 0.57), pH (R2 = 0.50) and then base excess (R2 = 0.25), while there was no correlation between the glycolate and ethylene glycol concentration (R2 = 0.00). These data can assist clinicians in planning treatments such as extracorporeal treatments and prognostication. Potentially, they may also provide some reassurance regarding when extracorporeal treatments can be delayed while awaiting the results of further testing in patients in whom ethylene glycol poisoning is suspected but not yet confirmed. CONCLUSIONS: This systematic review demonstrates that the glycolate concentration predicts mortality (unlikely if <8 mmol/L [61 mg/dL]). The anion gap is a reasonable surrogate measurement for glycolate concentration in the context of ethylene glycol poisoning. The findings are mainly based on published retrospective data which have various limitations. Further prospective validation studies are of interest.

Fomepizole dosing during continuous renal replacement therapy - an observational study.

BACKGROUND: Fomepizole is the preferred antidote for treatment of methanol and ethylene glycol poisoning, acting by inhibiting the formation of the toxic metabolites. Although very effective, the price is high and the availability is limited. Its availability is further challenged in situations with mass poisonings. Therefore, a 50% reduced maintenance dose for fomepizole during continuous renal replacement therapy (CRRT) was suggested in 2016, based on pharmacokinetic data only. Our aim was to study whether this new dosing for fomepizole during CRRT gave plasma concentrations above the required 10 µmol/L. Secondly, we wanted to study the elimination kinetics of fomepizole during CRRT, which has never been studied before. METHODS: Prospective observational study of adult patients treated with fomepizole and CRRT. We collected samples from arterial line (pre-filter) = plasma concentration, post-filter and dialysate for fomepizole measurements. Fomepizole was measured using high-pressure liquid chromatography with a reverse phase column. RESULTS: Ten patients were included in the study. Seven were treated with continuous veno-venous hemodialysis (CVVHD) and three with continuous veno-venous hemodiafiltration (CVVHDF). Ninety-eight percent of the plasma samples were above the minimum plasma concentration of 10 µmol/L. Fomepizole was removed during CRRT with a median saturation/sieving coefficient of 0.85 and dialysis clearance of 28 mL/min. CONCLUSION: Fomepizole was eliminated during CCRT. The new dosing recommendations for fomepizole and CRRT appeared safe, by maintaining the plasma concentration above the minimum value of 10 µmol/L. Based on these data, the fomepizole maintenance dose during CRRT could be reduced to half as compared to intermittent hemodialysis.

Osmolal and anion gaps after acute self-poisoning with agricultural formulations of the organophosphorus insecticides profenofos and diazinon: A pilot study.

Self-poisoning with organophosphorus (OP) insecticides is an important means of global self-harm. The insecticides are formulated with solvents that may also contribute to toxicity. We set up a study to detect changes in osmolal and anion gaps following ingestion of OP insecticides. We recruited consecutive patients admitted to a Teaching Hospital, Sri Lanka, with a history of OP self-poisoning. The osmolal and anion gaps were calculated on admission and at 4, 24 and 72 h post-ingestion together with ethanol concentration. Forty-nine patients were recruited (28 profenofos, 10 diazinon, one coumaphos, one chlorpyrifos, one phenthoate and eight unknown OP). Only modest increases in osmolal and anion gaps were noted. Small rises in osmolal gap above the upper limit of normal were noted in 16/49 (32.7%) of all cases, 9/28 (32.1%) profenofos cases and 4/10 (40.0%) diazinon cases. The anion gap was raised in 24/49 (49.0%) of all cases, 15/28 (53.6%) profenofos cases and 5/10 (50.0%) diazinon cases. We observed a trend for a fall in osmolal gap during the first 24 h, followed by an increase up to 72 h. There was no correlation between the anion gap and serum lactate concentration, indicating that a lactic acidosis was not responsible for the anion gap. Formate, which could have explained the increased gap, was not detected in any of the samples; ketoacids (beta-hydroxybutyrate and acetoacetate) were not measured. This pilot study found that profenofos and diazinon poisoning caused only modest increases in the osmolal and anion gaps in a minority of cases.

A survey of the antidote preparedness in Norwegian hospitals.

OBJECTIVES: Antidotes are an important part of the emergency preparedness in hospitals. In the case of a major chemical accident or a fire, large quantities of antidotes may be needed within a short period of time. For time-critical antidotes it is therefore necessary that they be immediately available. We wanted to evaluate the antidote preparedness in Norwegian hospitals as regards the national recommendations and compare this with other international guidelines. METHODS: A digital survey was sent to the 50 hospitals in Norway that treat acute poisonings. Of these, four hospitals are categorised as regional hospitals, 15 as large hospitals and 31 as small hospitals. Each hospital was asked which antidotes they stockpiled from a list of 35 antidotes. The financial costs (low, moderate, high) were added to an established efficacy scale to illustrate the cost-effectiveness of the different antidotes. RESULTS: The response rate was 100%. Eleven of fifty (22%) hospitals stockpiled all antidotes recommended for their hospital size. All four regional hospitals had all the recommended antidotes. Large hospitals which were not regional hospitals had the least availability of antidotes, and only one large hospital stockpiled all antidotes recommended for this hospital size. CONCLUSIONS: We found varying compliance with the national recommendations for antidote storage in hospitals. To strengthen antidote preparedness, we recommend standardised European guidelines to support national guidelines.

Formate test for bedside diagnosis of methanol poisoning.

Methanol poisoning kills thousands of people every year and remains a diagnostic challenge, especially where the resources are scarce, but also in high-income countries worldwide. We are in the course of developing a bedside strip to detect formate - the toxic metabolite of methanol. We hereby present the first clinical methanol case where formate was detected bedside from a drop of blood: The patient, a 61-year-old male, was admitted with a suspect methanol poisoning and severe metabolic acidosis. The test strip was positive after 3 minutes. Sodium bicarbonate (500 mmol/L), fomepizole, dialysis and folinic acid were given based on the positive test. The diagnosis was some hours later confirmed by GC-MS, showing a methanol concentration of 62 mmol/L (200 mg/dL) and a formate concentration of 19 mmol/L. Implementation of this technology into routine clinical use can potentially offer an opportunity for a step change in the management of methanol poisoning.

Rhabdomyolysis related to acute recreational drug toxicity-A Euro-DEN study.

BACKGROUND: This study was conducted to retrospectively assess the relationships between: rhabdomyolysis (quantified by creatine kinase (CK) activity) and kidney injury (quantified by serum creatinine concentration), sex, age, body temperature on admission, presence of seizures, and agitation or aggression in patients presenting to the Emergency Department with acute recreational drug toxicity. We also investigated the association with the substances ingested. METHODS: All presentations to the 16 sentinel Euro-DEN centres in 10 European countries with acute recreational drug toxicity during the first year of the Euro-DEN study (October 2013 to September 2014) were considered. Cases that had abnormal CK activity recorded as part of routine clinical care were divided into 3 cohorts depending on peak CK activity. Cases with normal CK activity were included as a control group (4th cohort). RESULTS: Only 1,015 (18.4%) of the 5,529 Euro-DEN presentations had CK activity concentration recorded. Of this group 353 (34.8%) had also creatinine concentration measured. There were 375 (36.9%) with minor rhabdomyolysis, 69 (6.8%) with moderate rhabdomyolysis, and 24 (2.4%) with severe rhabdomyolysis; 547 (53.9%) were included in the control group. There was a positive correlation between CK activity and creatinine concentration (correlation coefficient r = 0.71, p<0.0001). There was no correlation between CK activity and body temperature at the time of presentation to the ED (correlation coefficient r = 0.07, p = 0.03). There was a positive correlation between CK activity and length of stay in the hospital (r = 0.31, p<0.001). There was no association between CK activity and the presence of seizures (p = 0.33) or agitation/aggression (p = 0.45), patients age (p = 0.4) or sex (p = 0.25). The 5 most common agents amongst patients presenting with rhabdomyolysis were: cocaine (n = 107; 22.9% presentations), amphetamine (76; 16.2%), cannabis (74; 15.8%), GHB/GBL (72; 15.4%) and heroin (67; 14.3%). The distribution of rhabdomyolysis in 5 most common drugs was (drug; patients with rhabdomyolysis, patients without rhabdomyolysis): cocaine (107, 122), cannabis (74, 117), GHB/GBL (72, 81), amphetamine (76, 66), heroin (67, 70). CONCLUSIONS: Abnormal values of CK activity occurred in almost half (46.1%) of presentations to the Emergency Department with acute recreational drug toxicity in whom CK activity was measured; however, severe rhabdomyolysis is seen in only a small minority (2.4%). Those with rhabdomyolysis are at significantly higher risk of kidney injury and have a longer length of hospital stay.