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.

Atypical presentation of COVID-19; an observational retrospective study

BACKGROUND

COVID-19 infection may present with atypical signs and symptoms and false negative polymerase chain reaction (PCR) tests predisposing healthy people and health care workers to infection. The aim of the current study is to evaluate the features of atypical presentations in COVID-19 infection in a referral center in Tehran, Iran.

METHODS

Hospital database of inpatients admitted to Loghman Hakim hospital between February 20th and May 11th, 2020 was reviewed and all patients with final diagnosis of COVID-19 infection were evaluated for their presenting symptoms. Patients with chief complaints of "fever", "dyspnea", and/or "cough" as typical presentations of COVID-19 were excluded and those with other clinical presentations were included.

RESULTS

Nineteen patients were included with a mean age of 51 ± 19 years, of whom, 17 were males (89%). Median [IQR] Glasgow coma scale (GCS) was 14 [13, 15]. Almost 10 had referred with chief complaint of methanol poisoning and overdose on substances of abuse. Only 8 cases (42%) had positive COVID-19 test. Nine (47%) needed invasive mechanical ventilation, of whom, two had positive COVID-19 test results (p = ns). Eight patients (42%) died with three of them having positive PCRs.

CONCLUSIONS

In patients referring to emergency departments with chief complaint of poisoning (especially poisonings that can result in dyspnea including substances of abuse and toxic alcohols), gastrointestinal, and constitutional respiratory symptoms, attention should be given not to miss possible cases of COVID-19.

Methanol poisoning in Turkey: Two outbreaks, a single center experience

OBJECTIVES

Methanol poisoning is still one of the major causes of mortality due to intoxication because of the challenging diagnosis and late hospital admissions. We aimed to evaluate epidemiological data, clinical characteristics, laboratory findings, treatment protocols, and prognosis of patients in a tertiary hospital in two different methanol outbreaks occurring in a three-year interval.

METHODS

The study was planned as a single-center and retrospective observational case series study. Patients ≥18 years of age who were admitted to the hospital between 1 September 2016 and 1 September 2019 and diagnosed with methanol poisoning were included in the study.

RESULTS

Sixty-seven patients whose data were sufficient and accessible were included in the study. Thirty-five (52.2%) patients were discharged without sequelae, 14 (20.9%) patients were discharged with sequelae (both central nervous system sequelae and visual sequelae in 3 patients, only visual sequelae in 11 patients) and 18 (26.9%) patients died. High anion gap (AG) metabolic acidosis (pH < 7.07, AG > 26.7), low Glasgow Coma Score, and increased lactate (lactate > 2.55 mmol/L) levels were found to be associated with poor outcome. Folate use in treatment did not have a statistically significant effect (p = 0.087) on the prevention of visual sequelae development, but it had a statistically significant effect on mortality (p = 0.041).

CONCLUSIONS

State of consciousness and the severity of metabolic acidosis were significant parameters associated with mortality. In addition to antidote and elimination therapies, given the benefit on mortality and low risk of adverse events, folate therapy should be considered for all patients with significant toxic methanol exposures.

Alcohol intake in an attempt to fight COVID-19: A medical myth in Iran

The coronavirus disease 2019 (COVID-19) spread rapidly worldwide and led to the deaths of thousands of people. To date, there is not any vaccine or specific antiviral medicine that can prevent or treat this virus. This caused panic among people who try their best to prevent being infected. In Iran, methanol poisoning was reported and led to the death of hundreds of people in several provinces. The incident occurred after a rumor circulated in the country that drinking alcohol (ethanol) can cure or prevent being infected by COVID-19.

Electrocardiographic findings of methanol toxicity: a cross-sectional study of 356 cases in Iran

BACKGROUND

Methanol is widely used in industry; however, methanol poisoning is not common. In this regard, a number of outbreaks have been recently reported due to inappropriate processing of alcoholic beverages. Shiraz, a city located in the southern part of Iran, faced one of such outbreaks in 2020 during COVID-19 pandemic. There is no sufficient literature on the electrocardiographic findings in methanol toxicity. This study aimed to address this gap in the literature.

METHOD

A total of 356 cases with methanol toxicity referred to Shiraz University of Medical Science Tertiary Hospitals (Faghihi and Namazi) in March and April, 2020. The clinical findings of blindness and impaired level of consciousness, lab data such as arterial blood gas, electrolytes, and creatinine, and the most common findings from ECGs were collected.

RESULTS

The most common ECG findings were J point elevation (68.8%), presence of U wave (59.2%), QTc prolongation (53.2% in males and 28.6% in females), and fragmented QRS (33.7%). An outstanding finding in this study was the presence of myocardial infarction in 5.3% of the cases. This finding, to the best of our knowledge, has only been reported in a few case reports. Brugada pattern (8.1%) and Osborn wave (3.7%) were the other interesting findings. In multivariate analysis, when confounding factors were adjusted, myocardial infarction, atrioventricular conduction disturbances, sinus tachycardia, and the prolonged QTC > 500 msecond were four independent factors correlated with methanol toxicity severity measured with arterial blood PH on arterial blood gas measurements, with odds ratios of 12.82, 4.46, 2.32 and 3.15 (P < 0.05 for all), respectively.

CONCLUSION

Electrocardiographic variations during methanol intoxication are remarkable and well-correlated with poisoning severity. Myocardial infarction was an egregious and yet a common concerning finding in this sample, which need to be ruled out in methanol toxicity.

A syndemic of COVID-19 and methanol poisoning in Iran: Time for Iran to consider alcohol use as a public health challenge?

Methanol poisoning has been a significant public health challenge for several decades in Iran. Even though alcohol use is highly criminalized, people consume illicit alcohol, which tends to be predominantly homemade and often contains methanol. Consequently, thousands of individual poisonings and hundreds of deaths annually are attributable to methanol poisoning. From February 19, 2020 through April 27, 2020, the 2019 coronavirus disease (COVID-19) epidemic rapidly expanded in Iran, and has been associated with 90,481 confirmed cases and 5710 confirmed deaths. Secondary to misinformation about the potential for alcohol to neutralize SARS-CoV-2, there has also been a significant escalation in methanol-related morbidity and mortality, with over 5000 people poisoned and over 500 confirmed deaths for the same period from February through April 2020. In some provinces, the case-fatality rate of methanol poisoning was higher than that from COVID-19. The high morbidity and mortality associated with methanol poisoning preceding and exacerbated by COVID-19 highlight the potential population level health impacts of the implementation of evidence-based education and harm reduction strategies focused on alcohol use across Iran.

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Mass methanol poisoning outbreaks have become a major public health concern in Iran.

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More than 5000 methanol poisonings, with more than 500 confirmed deaths, were reported amid the COVID-19 epidemic in Iran.

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Policymakers should consider developing and implementing public health models to address alcohol use problems.

Dilemma in the management of methanol poisoning at a district hospital in Malaysia

There are increasing reports of methanol poisoning (MP) incidence worldwide. In Malaysia, the largest first methanol poisoning was reported in Selangor in 2013 with a total of 41 patients and cluster of cases been reported from the country since then. Often MP involved adulterated alcohol containing more than the legal permissible concentration of methanol. Methanol is rapidly absorbed and metabolised into formic acid which causes variable symptoms of the central nervous system such as blindness, seizure, coma and gastrointestinal disturbances. Mortality could reach up to 83% as reported using the coma state, pH and pCO2 level in the worst-case scenario.

Secondary visual loss due to inhalation and cutaneous poisoning by methanol and toluene. Presentation of a clinical case

Methanol poisoning is often described in the literature, but not transdermal or inhalational poisoning. It usually involves variable multi-organ damage, among which visual, neurological, and gastrointestinal involvement, as well as the metabolic and electrolyte changes that can lead to death. Contact with toluene by occupational or intentional inhalation may also cause neurological abnormalities. This article describes the case of a female patient who was seen in the Emergency Department due to bilateral visual loss secondary to accidental poisoning (inhalation-transdermal) with a solvent containing methanol and toluene. She had a favourable outcome during admission after treatment with ethanol in perfusion and corticosteroids.

Methanol related death in National Institute of Forensic Medicine, Hospital Kuala Lumpur: A case series

INTRODUCTION

Methanol is a widely available chemical with a range of uses including as solvent, as a fuel, in chemical synthesis and anti-freeze preparations. Most of the cases are accidental exposures to drinking beverages contaminated with methanol.

MATERIALS AND METHODS

In mid-September 2018, there was a single outbreak of methanol poisoning in Malaysia especially involving the state of Federal Territory Kuala Lumpur and Selangor. There were 33 reported deaths suspected due to methanol poisoning in this current outbreak where 11 of them were brought in to the Institute of Forensic Medicine (NIFM), Kuala Lumpur. The last outbreak was in the year 2013 with 29 deaths reported out of 44 cases.

RESULTS

There were 3 cases (27.2%) died in hospital and the remaining 8 cases (72.8%) were found dead at home and were later brought in dead to the hospital. A full autopsy was carried out for each case. Autopsy findings, as well as lab results pertaining to cases that survived and directly brought in dead, were of a different spectrum.

CONCLUSION

Methanol related deaths are almost always as a result of greed. The running truism is 'methanol poisoning is a result of deliberate addition/adulteration with industrial methanol'. Prevention of the illegal production of methanol and methylated spirits should be established to curb this matter in the future.

SPME-GC/MS Analysis of Methanol in Biospecimen by Derivatization with Pyran Compound

Methanol is metabolized in the body to highly toxic formaldehyde and formate when consumed accidentally. Methanol has been typically analyzed with gas chromatography-flame ionization detector (GC-FID). However, its retention time may overlap with other volatile compounds and lead to confusion. Alternative analysis of methanol using gas chromatography/mass spectrometry (GC/MS) also has limitations due to its similar molecular weight with oxygen and low boiling point. In this study, methanol and internal standard of deuterium-substituted ethanol were derivatized with 3,4-dihydro-2H-pyran under acid catalysis using concentrated hydrochloric acid. The reaction products including 2-methoxytetrahydropyran were extracted with solid-phase microextraction followed by GC/MS analysis. This method was successfully applied to measure the lethal concentration of methanol in the blood of a victim with a standard addition method to overcome the complex matrix effect of the biospecimen. Identification of the metabolite formate by ion chromatography confirmed the death cause to be methanol poisoning. This new method was a much more convenient and reliable process to measure methanol in complex matrix samples by reducing sample pretreatment effort and cost.

Methanol outbreak in the district of Hulu Langat, 2018

INTRODUCTION

A methanol outbreak occurred in the district of Hulu Langat on 16 September 2018. The Hulu Langat District Health Office received 25 notifications of a suspected methanol poisoning from Kajang and Ampang Hospital. An outbreak investigation was done to determine the source followed by a preventive and control measure.

METHOD

Active case detection was done on cases living quarters and workplaces. Patients were interviewed, and their blood and urine samples were sent for methanol analysis. Samples of suspected alcoholic beverages were also sent for analysis. A suspected case was defined as any person presented with clinical symptoms with a history of consuming alcoholic beverages within five days before symptoms and high anion gap metabolic acidosis. A confirmed case was defined as a suspected case with positive blood and urine methanol.

RESULTS

In total, there were 25 suspected cases, of which 12 cases were confirmed. The calculated attack rate was 48%. There were six mortalities (50%) secondary to severe metabolic acidosis. The most common presenting symptom was vomiting (75%) and abdominal pain (41.7%). These cases were linked to consumption of illicitly produced alcohol. Samples of the alcoholic drinks were positive containing high level of methanol.

CONCLUSION

The methanol outbreak in the Hulu Langat was successfully managed. Appropriate control and prevention measures were taken, including health promotion and joint enforcement activities. Steps were taken successfully through collaborations with multiple agencies and cooperation with Selangor Health Departments and the Ministry of Health. Continuous surveillance on the product of liquor, and health promotion are essential to prevent a similar outbreak from happening again in future.

[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.

Toxic Alcohol Ingestion/Methanol Ingestion

INTRODUCTION

Methanol poisoning is an uncommon life-threatening ingestion associated with significant morbidity and requires prompt diagnosis and management for the best possible outcome. We created a simulation case that challenges learners to analyze case information, construct a differential diagnosis of an anion gap metabolic acidosis, narrow the differential based on reasoning, and empirically initiate management.

METHODS

The simulation case was designed for emergency medicine residents and pediatric emergency medicine fellows. The activity began with a brief overview of the monitors, equipment, and simulation experience. First-year residents managed the case as a team of two. Second- and third-year residents and fellows managed the case alone. The learners had 15 minutes to complete a focused history and physical exam, request and interpret labs and studies, provide stabilization of life threats, and initiate specific interventions based on a presumptive diagnosis. The simulation was followed by a 20-minute facilitated debrief session that reviewed key learning points and learner performance based on an evaluation checklist.

RESULTS

Residents completed a six-question, 5-point Likert-scale postparticipation questionnaire. Overall, residents reported a high degree of satisfaction with the simulation experience. The case and debrief were effective in meeting the educational objectives and proved to be an effective modality to fill this educational gap.

DISCUSSION

This simulation experience successfully exposed residents to the uncommon presentation of methanol poisoning. The simulation experience effectively closed the identified educational gap and provided an experiential learning opportunity that accomplished the targeted learning objectives.

Methanol as an Unlisted Ingredient in Supposedly Alcohol-Based Hand Rub Can Pose Serious Health Risk

Alcohol-based hand rub (hand sanitizer) is heavily used in the community and the healthcare setting to maintain hand hygiene. Methanol must never be used in such a product because oral, pulmonary and/or skin exposures can result in severe systemic toxicity and even deaths. However, sporadic cases of acute poisoning indicate that alcohol-based hand rub with undeclared methanol may be found in the market from time to time. The unexpected presence of methanol poses a serious threat to public health. Unintentional ingestion by young children and inadvertent consumption by older subjects as alcohol (ethanol) substitute can occur. Methanol is more lethal and poisoning often requires antidotal therapy, in addition to supporting therapy and critical care. However, specific therapy may be delayed because the exposure to methanol is initially not suspected. When repeatedly used as a hand rub, skin absorption resulting in chronic toxicity (e.g., visual disturbances) occurs, particularly if methanol induced desquamation and dermatitis are present. Nationwide surveillance systems, regional/international toxicovigilance networks and situational awareness among the healthcare professionals should facilitate the early detection, management and prevention of such poisoning incidents of public health significance.

Progressive Chronic Retinal Axonal Loss Following Acute Methanol-induced Optic Neuropathy: Four-Year Prospective Cohort Study

PURPOSE

To study the dynamics and clinical determinants of chronic retinal nerve fiber layer thickness (RNFL) loss after methanol-induced optic neuropathy.

DESIGN

Prospective cohort study.

METHODS

All patients underwent complete ophthalmic evaluation including spectral-domain optical coherence tomography 3 times during 4 years of observation: 4.9 (±0.6), 25.0 (±0.6), and 49.9 (±0.5) months after discharge.

PARTICIPANTS

Eighty-four eyes of 42 survivors of methanol poisoning, mean age (standard deviation) of 45.7 (±4.4) years; and 82 eyes of 41 controls, mean age 44.0 (±4.2) years.

MAIN OUTCOME MEASURES

Global and temporal RNFL loss.

RESULTS

Abnormal RNFL thickness was registered in 13 of 42 (31%) survivors of methanol poisoning and chronic axonal loss in 10 of 42 (24%) patients. Significant decrease of global/temporal RNFL thickness during the observation period was found in the study population compared to the controls (P < .001). The risk estimate of chronic global RNFL loss for arterial blood pH < 7.3 at admission was 11.65 (95% confidence interval 1.91-71.12) after adjusting for age and sex. The patients with chronic axonal degeneration demonstrated progressive visual loss in 7 of 10 cases. The patients with abnormal RNFL thickness had magnetic resonance signs of brain damage in 10 of 13 vs 8 of 29 cases with normal RNFL thickness (P = .003). Signs of brain hemorrhages were present in 7 of 13 patients with abnormal RNFL thickness vs 5 of 29 cases with normal RNFL thickness (P = .015).

CONCLUSIONS

Methanol-induced optic neuropathy may lead to chronic retinal axonal loss during the following years. Arterial blood pH on admission is the strongest predictor of chronic RNFL thickness decrease. Chronic retinal neurodegeneration is associated with the progressive loss of visual functions and necrotic brain lesions.

Methanol Poisoning

Mortality associated with methanol has been of great concern time and again. The concurrence of cases from a particular area raises doubts about methanol as the culprit. Knowledge of the patho-physiological changes that occur in the body after methanol consumption is essential for all practicing doctors. This article elucidates the clinical presentation and emergency management of these cases under the framework of basic physiological and biochemical phenomena after methanol exposure. Conversion of methanol to formaldehyde by hepatic enzyme alcohol dehydrogenase triggers the cascade of metabolic events. The manifestations begin as early as 30 minutes and progress to decompensated metabolic acidosis in about 12 hours, if left untreated. Seizures, hypoglycemia and blindness frequently complicate the picture. Acute kidney injury warrants urgent haemodialysis. Fundoscopic examination and arterial blood gas analysis are the key diagnostic elements. The management comprises of intravenous sodium bicarbonate, correction of dyselectrolytemia, ethanol, folic acid and haemodialysis, if necessary. The basic steps in approach must be carried out in the emergency department and followed-up with meticulous monitoring in the intensive care unit for salvage as well as prevention of long term sequelae.

Homicidal methanol poisoning in filicide-suicide

Most methanol poisonings are accidental. We present a rare case of filicide-suicide, where a youth was killed by methanol poisoning and his parents then committed suicide by jumping in front of a running train. The father's suicide note explains the crime.

Methanol poisoning: 27 years experience at a tertiary care hospital

Methanol toxicity can result in serious morbidity and mortality without timely diagnosis and treatment. Many cases of methanol poisoning outbreaks have been noted in our population but no study has been performed to estimate methanol exposure and its outcomes and complications. A retrospective study was conducted to review all the cases of methanol poisoning admitted from January 1988 to December 2015 at the Aga Khan University Hospital. A total of 35 methanol poisoning cases were reported. All the patients were male, and the mean age was 36.2±8.6 years. The mean Glasgow Coma Scale score on presentation in the emergency was 10.4 ± 4.4. Blurring of vision was present in 17 (48%) patients while 10 (28%) had complete blindness. Mean arterial pH was 6.8±0.5 on arrival. Ethanol was given to 30(88%) patients and 12(32%) patients received bicarbonate for immediate treatment. A total of 15 (42.8%) patients underwent dialysis, out of which only 5 (33.3%) patients survived. Overall, 19 (54.3%) patients expired secondary to methanol ingestion.

Neurological Complications Resulting from Non-Oral Occupational Methanol Poisoning

Methanol poisoning results in neurological complications including visual disturbances, bilateral putaminal hemorrhagic necrosis, parkinsonism, cerebral edema, coma, or seizures. Almost all reported cases of methanol poisoning are caused by oral ingestion of methanol. However, recently there was an outbreak of methanol poisoning via non-oral exposure that resulted in severe neurological complications to a few workers at industrial sites in Korea. We present 3 patients who had severe neurological complications resulting from non-oral occupational methanol poisoning. Even though initial metabolic acidosis and mental changes were improved with hemodialysis, all of the 3 patients presented optic atrophy and ataxia or parkinsonism as neurological complications resulting from methanol poisoning. In order to manage it adequately, as well as to prevent it, physicians should recognize that methanol poisoning by non-oral exposure can cause neurologic complications.

Acute Renal Injury Following Methanol Poisoning: Analysis of a Case Series

The objective of this paper is to document the prevalence of indicators of acute renal injury in a series of methanol-poisoned patients treated in an intensive care unit and to discuss the possible mechanisms. This is a retrospective analysis of the medical records of 25 consecutive patients admitted to the intensive care unit after severe intentional methanol poisoning. Acute renal impairment was defined as a serum creatinine concentration higher than 177 μmol/L and/or a urinary output on admission and for the first 24 h below 0.5 ml/kg/h. Clinical pathological signs of acute renal injury were found in 15 patients. In comparison with the 10 other patients taken as control group, the patients who developed renal injury had a lower blood pH value on admission, a higher serum osmolality, and a higher peak formate concentration. Two factors contributing to renal injury could be identified: hemolysis and myoglobinuria. The role of osmotic changes (“osmotic nephrosis”) or of a direct cytotoxic effect of formic acid remains speculative. Analysis of proteinuria suggests that proximal tubular cells may be preferentially affected. Results of histopathological evaluation of the kidney on a limited sample size ( n = 5) were inconclusive but suggestive of possible hydropic changes in the proximal tubule secondary to methanol toxicity. Acute renal injury may be associated with other signs of severity in methanol poisoning, but it is almost always reversible in survivors. Indicators of acute renal injury were identified. The pathophysiology of this acute renal injury is multifactorial and far more complex than shock-related tubular necrosis.

Visual and neurologic sequelae of methanol poisoning in Saudi Arabia

Objectives:

To present the visual sequelae of methanol poisoning and to emphasize the characteristics of methanol exposure in the Kingdom of Saudi Arabia (KSA).

Methods:

A retrospective case series was carried out on 50 sequential patients with methanol poisoning seen at the King Khaled Eye Specialist Hospital and King Saud University Hospitals in Riyadh, KSA between 2008 and 2014. All patients were examined by a neuro-ophthalmologist at least one month after methanol intoxication.

Results:

All 50 patients were young or middle-aged males. All admitted to drinking unbranded alcohol within 2-3 days before profound or relatively profound, painless, bilateral visual loss. Mean visual acuity in this group was hand motions (logMAR 2.82; range 0.1 - 5.0) with some eye to eye variability within individuals. Worse visual acuity was correlated with advancing age (Pearson correlation: oculus dextrus [right eye] - 0.37, p=0.008; oculus sinister [left eye] - 0.36, p=0.011). All patients had optic atrophy bilaterally, and all tested patients had visual field defects. Tremors with or without rigidity were present in 12 patients, and 11 of 30 patients who had neuroimaging performed had evidence of putaminal necrosis.

Conclusion:

Methanol intoxication causes visual loss within 12-48 hours due to relatively severe, painless, bilateral optic nerve damage that may be somewhat variable between eyes, and is generally worse with advancing age. The coincidence of bilateral optic nerve damage and bilateral putaminal necrosis in a young or middle-aged male is very suspicious for methanol-induced damage.

A Brief Review on Toxic Alcohols: Management Strategies

The information on burden of alcohol abuse in Iran is scarce. However, the available data show that mortality rates and frequency of its use have increased in the Iranian community. In particular, Iran occupies the 1st rank in the number of outbreak incidents and victims of toxic alcohols such as methanol in the Middle East. Mortality and morbidity of toxic alcohols are high if prompt diagnosis and treatment are not initiated rapidly. On-time diagnosis, proper case finding, and standard treatment have an essential role to reduce mortality and morbidity of toxic alcohols particularly blindness and other physical and psychological disabilities. This review focuses on intoxication with methanol, ethylene glycol, and isopropanol, and their treatment.

Toxic alcohol ingestion: prompt recognition and management in the emergency department [digest]

Identifying patients with potential toxic alcohol exposure and initiating appropriate management is critical to avoid significant patient morbidity. Sources of toxic alcohol exposure include ethylene glycol, methanol, diethylene glycol, propylene glycol, and isopropanol. Treatment considerations include the antidotes fomepizole and ethanol, and hemodialysis for removal of the parent compound and its toxic metabolites. Additional interventions include adjunctive therapies that may improve acidosis and enhance clearance of the toxic alcohol or metabolites. This issue reviews common sources of alcohol exposure, basic mechanisms of toxicity, physical examination and laboratory findings that may guide rapid assessment and management, and indications for treatment. [Points & Pearls is a digest of Emergency Medicine Practice].

Toxic Alcohol Ingestion: Prompt Recognition And Management In The Emergency Department

Identifying patients with potential toxic alcohol exposure and initiating appropriate management is critical to avoid significant patient morbidity. Sources of toxic alcohol exposure include ethylene glycol, methanol, diethylene glycol, propylene glycol, and isopropanol. Treatment considerations include the antidotes fomepizole and ethanol, and hemodialysis for removal of the parent compound and its toxic metabolites. Additional interventions include adjunctive therapies that may improve acidosis and enhance clearance of the toxic alcohol or metabolites. This issue reviews common sources of alcohol exposure, basic mechanisms of toxicity, physical examination and laboratory findings that may guide rapid assessment and management, and indications for treatment.

Conventional and diffusion-weighted MRI in the evaluation of methanol poisoning

Cerebral lesions were studied in 2 methanol-poisoned patients using conventional magnetic resonance imaging (MRI). In 1 patient, diffusion-weighted MRI (DWI) was also performed. In this patient, conventional MRI showed symmetrical, bilateral increased signal in the lentiform nuclei, involving predominantly putamina, but also extending into the corona radiata, centrum semiovale and subcortical white matter. DWI showed decreased diffusion, which most probably reflects cytotoxic edema. In the other patient, fluid attenuated-inversion recovery (FLAIR) and T2-weighted images showed hyperintensity in the putamina, characteristic of post-necrotic changes.

Prognostic factors in methanol poisoning

The aim of this study was to assess the clinical and laboratory factors in methanol poisoned patients to determine the prognosis of their toxicity. This survey was done as a prospective cross-sectional study in methanol-poisoned patients in Loghman-Hakim hospital poison center during 9 months from October 1999—June 2000. During this time 25 methanol-poisoned patients were admitted. The mortality rate was 12 (48%). Amongst survivors, three (23%) of the patients developed blindness due to their poisoning and the other 10 (77%) fully recovered without any complication. The mortality rate in comatose patients was nine (90%) while in non-comatose patients it was three (20%) ( P < 0.001). There was a significant difference in mean pH in the first arterial blood gas of patients who subsequently died (6.82 ± 0.03) and survivors (7.15 ± 0.06) ( P < 0.001, M-W). The mean time interval between poisoning and ED presentation in deceased patients were (46 ± 15.7) hours, in survived with sequelae were (16.7 ± 6.7) and in survived without sequelae were (10.3 ± 7.2) hours ( P < 0.002, K-W). We found no significant difference between the survivors versus the patients who died regarding methanol. Simultaneous presence of ethanol and opium affected the outcome of the treatment for methanol intoxication favourably and unfavourably, respectively. In our study, poor prognosis was associated with pH < 7, coma on admission and >24 hours delay from intake to admission. Human & Experimental Toxicology (2007) 26: 583—586.

Formate kinetics in methanol poisoning

Objective: The objective is to describe the kinetics of formate, the main toxic metabolite of methanol, in a series of consecutive patients treated in the same intensive care unit for severe methanol poisoning. Methods: The charts of the patients admitted between 1987 and 2001 were reviewed. Inclusion criteria were: a history of deliberate methanol ingestion, with a blood methanol concentration greater than 20 mg/dL (6.2 mmol/L) or a high anion gap metabolic acidosis. Indications for hemodialysis were: blood methanol concentration>50 mg/dL (15.8 mmol/L), metabolic acidosis (bicarbonate < 15 mmol/L, arterial pH < 7.30), visual toxicity. Antidotal therapy included ethanol administration in 22 cases, and fomepizole in three cases. Serial blood measurements were obtained for pH, bicarbonate, methanol and formate. Endogenous and hemodialysis elimination half-lives were calculated as t1/2=0.693/Ke. Fick principle was applied for hemodialysis clearance calculation. Results: The records of 25 methanol poisoned patients were analysed. Among them, 18 patients had sufficient data to allow accurate determinations of formate kinetics. Formate half-life elimination during hemodialysis was 1.809 ± 0.78 h, which was statistically different from the values observed before or in the absence of dialysis (6.049 ± 3.26 h, P=0.004). The mean hemodialysis formate clearance rate calculated in eight cases was 1769 ± 43 mL/min. A rebound in plasma formate concentration was observed in three patients after the discontinuation of hemodialysis. Conclusions: In accordance with previous isolated case reports and in contrast with a recent case series, our data document that hemodiaysis is effective in reducing formate elimination half-life. The impact on clinical outcome is still debatable.

The Methanol Poisoning Outbreaks in Libya 2013 and Kenya 2014

BACKGROUND

Outbreaks of methanol poisoning occur frequently on a global basis, affecting poor and vulnerable populations. Knowledge regarding methanol is limited, likely many cases and even outbreaks go unnoticed, with patients dying unnecessarily. We describe findings from the first three large outbreaks of methanol poisoning where Médecins Sans Frontières (MSF) responded, and evaluate the benefits of a possible future collaboration between local health authorities, a Non-Governmental Organisation and international expertise.

METHODS

Retrospective study of three major methanol outbreaks in Libya (2013) and Kenya (May and July 2014). Data were collected from MSF field personnel, local health personnel, hospital files, and media reports.

FINDINGS

In Tripoli, Libya, over 1,000 patients were poisoned with a reported case fatality rate of 10% (101/1,066). In Kenya, two outbreaks resulted in approximately 341 and 126 patients, with case fatality rates of 29% (100/341) and 21% (26/126), respectively. MSF launched an emergency team with international experts, medications and equipment, however, the outbreaks were resolving by the time of arrival.

INTERPRETATION

Recognition of an outbreak of methanol poisoning and diagnosis seem to be the most challenging tasks, with significant delay from time of first presentations to public health warnings being issued. In spite of the rapid response from an emergency team, the outbreaks were nearly concluded by the time of arrival. A major impact on the outcome was not seen, but large educational trainings were conducted to increase awareness and knowledge about methanol poisoning. Based on this training, MSF was able to send a local emergency team during the second outbreak, supporting that such an approach could improve outcomes. Basic training, simplified treatment protocols, point-of-care diagnostic tools, and early support when needed, are likely the most important components to impact the consequences of methanol poisoning outbreaks in these challenging contexts.

[Antidote update]

In Japan, several products of the antidote for poisoning have been authorized in clinical use from some recent years. For example, Hydroxcobalamin for cyanide poisoning was introduced in 2008. In 2009, Ministry of Health, Labour and Welfare invited suggestions of demand of pharmaceutical products which is high in the need in the medical care but yet unauthorized. Japanese Society for Clinical Toxicology and Japan Poison Information Center applied some candidates including methyleneblue (MB) and fomepizole, both of them were authorized in clinical market in 2015. MB is the medicine for methemoglobinemia, caused by variety of chemical products such as nitrogen oxide. Fomepizole is the antidote for methanol and ethyleneglycol, blocking alcohol dehydrogenase.

[Methanol: the threat of intoxication is still there]

Methanol mass poisoning occurs across the world quite frequently, but the complete clinical and laboratory data of the patients are only rarely available. Approximately 138 cases of poisoning were documented in the Czech Republic, 107 patients were hospitalized. Another 31 persons died out of hospital. About 60 % of the hospitalized patients survived intoxication without consequences, one half of the remaining 40 % died and the other half survived with the CNS and/or sight impaired. The Czech study successfully used modern diagnostic methods. A positive effect of the prehospital first aid with an oral antidote has been proven and a comparable effect of ethanol and fomepizole has been reached during hospital therapy. Higher efficiency of intermittent therapy has been determined as compared to continual hemodialysis. No connection was found between cerebral hemorrhage and systemic anticoagulation during hemodialysis. Magnetic resonance imaging revealed brain lesions in more than 50 % of the examined persons. During the follow-up visits over months and years improvement regarding the damage to the optic nerve was found in patients with a lesion of mild to medium degree. Isolated cases of poisoning still occur.

KEY WORDS

antidote - long-term follow-up - hemodialysis - methanol - methanol intoxication - CNS damage - vision impairment.

[EFFECT OF 4-METHYLPYRAZOLE ON IMMUNE RESPONSE, FUNCTION OF Th1 AND Th2 LYMPHOCYTES, AND CYTOKINE CONCENTRATION IN RAT BLOOD AFTER ACUTE METHANOL POISONING]

It was established in experiments on noninbred albino rats that the acute intoxication with methanol (1.0 LD50) decreased cellular and humoral immune responses, Th2-lymphocyte activity (to a greater extent as compared to the function of Th1 cells), reduced the blood concentration of immunoregulatory (IFN-g, IL-2, IL-4) and proinflammatory (TNF, IL-1b, IL-6) cytokines on the average by 36.5% (p < 0.05), and did not affect the content of anti-inflammatory cytokines (IL-10, IL-13). Methanol antidote 4-methylpyrazole (non-competitive inhibitor of alcohol dehydrogenase) administered upon acute intoxication with methanol at a dose of 1.0 DL50 partially reduces the intoxication-induced suppression of humoral and cellular immune response, activity of T-helper cells, and production of IL-4 and restores blood levels of TNF, IL-1b, IFN-γ, IL-4, IL-2, IL-6 to the control values.

[Toxic alcohol poisonings]

Accidental or intentional poisonings with ethylene glycol or methanol constitute a serious toxicological problem in many countries. Both alcohols are quickly metabolized by alcohol dehydrogenase to toxic metabolites responsible for high anion gap severe metabolic acidosis and profound neurological, cardiopulmonary, renal disturbances and death. In the early period, the competing inhibition the alcohol dehydrogenase with ethanol or fomepizol may successfully prevent the formation of the toxic metabolites. Once severe acidosis develops an emergency hemodialysis is required.

Methanol Induced Toxic Amblyopia--A Case Report

A 28-year-old man, smoker having history of occasional alcohol intake--was admitted in the Department of Medicine, Bangabandhu Sheikh Mujib Medical University (BSMMU) with gradual diminution of vision in both eyes 10 days after consumption of homemade alcoholic beverage in a wedding ceremony. His initial acuity of vision was limited to no perception of light in right eye and hand movement in left eye. Fundus examination revealed pale optic discs in both eyes. The patient was treated with Injection Methylprednisolone 1000 mg intravenous slowly over 1 hour for 3 consecutive days. This was followed by oral prednisolone 60 mg daily for 14 days and then gradually tapered over 4 weeks. The patient also received Injection Hydroxycobalamine and Injection Folinic Acid for 2 weeks. On the 3rd day of treatment there was perception of light in the right eye and on the 10th day the visual acuity improved to hand movement. In the left eye, the visual acuity gradually improved to 6/60 on 3rd day and on 10th day improved to 6/24. Four weeks later, the visual acuity had recovered in both eyes to 6/18. Combination of intravenous and oral steroid along with vitamin B1 and folinic acid has been found effective in treating severe methanol induced optic neuropathy.

[Distribution of Formic Acid after Methanol Intoxication in Rats]

OBJECTIVE

To investigate concentration and distribution in blood and tissues of formic acid after methanol intoxication in rats.

METHODS

The Sprague-Dawley rats were divided into groups for control group and 3-day and 7-day intoxication treatment groups. The experimental groups were administered methanol by gavage with the initial dose of 8 mL/kg and followed with 4 mL/kg supplemental dose 24 h later. After 3 days and 7 days later, rats were killed by decapitation. Then samples of cardiac blood, liver, kidney, brain, heart and stomach of each group were collected. Formic acid concentrations were detected by high performance liquid chromatography.

RESULTS

Formic acid concentrations in tissues were higher than in blood. Compared with 3-day intoxication group, there was an increase formic acid of concentration in brain and stomach in 7-day intoxication group, while a decrease in liver and kidney (P < 0.05).

CONCLUSION

High performance liquid chromatography could be used to accurately detect formic acid. As the metabolite of methanol, formic acid accumulates in rat blood and tissues after intoxication and the concentrations in organs and tissues are obviously higher than in blood.

Long-term visual damage after acute methanol poisonings: Longitudinal cross-sectional study in 50 patients

CONTEXT

Visual disturbances due to the toxic effect of formic acid in acute methanol poisonings are generally transient. The subjective symptoms of visual toxicity may resolve within few weeks and fundoscopic signs of acute optic neuropathy subside within 1-2 months; therefore, the prevalence of long-term visual sequelae in the population of survivors of poisonings may be underestimated.

OBJECTIVE

To study the prevalence and character of long-term visual sequelae of acute methanol poisonings based on the data from the Czech mass methanol outbreak in 2012.

PATIENTS AND METHODS

A total of 50 patients with confirmed methanol poisoning were included in this longitudinal cross-sectional study, median age: 48 (range, 23-73) years. The following tests were performed: optical coherence tomography or OCT with evaluation of the retinal nerve fibers layer (RNFL), visual evoked potentials (VEP), magnetic resonance imaging (MRI) of brain, complete ocular examination (visual acuity/field, color vision, contrast sensitivity, and fundus), neurological examinations, and biochemical tests.

RESULTS

Of 50 patients, 7/50 (14%) were discharged with diagnosed visual sequelae and 6/50 (12%) were discharged with both visual and central nervous system sequelae of poisoning. On the follow-up examination, 20/50 (40%) of the patients had long-term visual sequelae, with 8% of blindness. A total of 38% of the patients had abnormal (28% borderline) findings on RNFL, and 40% had abnormal (18% borderline) VEP. Among the patients discharged without detected visual sequelae, 8/37 (22%) had abnormal RNFL and VEP. Patients with visual sequelae had brain lesions more often (70% vs. 27%, p < 0.01). MRI identified optic nerve lesions in 2/20 cases with abnormal VEP only. The groups with and without visual sequelae differed in serum methanol, ethanol, HCO3-, formate, pH, anion gap, and base deficit (all p < 0.01). Visual disturbances on admission and coma were more prevalent in the patients with visual sequelae (p < 0.05). Patients with positive serum ethanol on admission were 93% less likely to have optical axonal damage (OR: 0.07 (95% CI: 0.01-0.8); p < 0.05). No association was found between visual sequelae and type of antidote administered, mode of hemodialysis, or folate substitution. Pre-hospital administration of ethanol seemed beneficial: these patients were 90% less likely to have abnormal RNFL findings (OR: 0.10 (95% CI: 0.02-0.52); p < 0.01).

CONCLUSIONS

The long-term visual sequelae were clearly underestimated on discharge, suggesting a significantly higher amount of patients with long-term sequelae than earlier reported. Thorough examinations before discharge and during follow-up will likely uncover a higher morbidity also after methanol poisonings in general.

[Study of blood concentration analysis for formate in acute methanol poisoning]

A 53-year-old woman ingested about 300 mL of 95% methanol. After immediate ethanol antagonist therapy and hemodialysis, she recovered completely. Few days later, the plasma concentration of methanol and formate was measured. A gas chromatography was used for the plasma methanol concentration measurement, and a colorimetric method was used for plasma formate concentration measurement (Formate Colorimetric Assay Kit; BioVision, California, USA). Patient's plasma methanol concentration before hemodialysis was 676.9 mg/dL and plasma formate concentration was 16.9 mg/dL. By removing blood methanol and formate using hemodialysis before formate accumulations in the body, the patient was discharged without any sequelae. We were able to obtain correlation between a gas chromatography and colorimetric method without gas chromatography-mass spectrometry, with good correlation coefficients. The sensitivity was sufficient for analyzing blood sample. Monitoring formate concentration is useful in determining the treatment and evaluating the prognosis of methanol poisoning. We suggest that this colorimetric method is useful in a facility with no access to a gas chromatography in order to measure a plasma formate concentration.

Acute self-induced poisoning with sodium ferrocyanide and methanol treated with plasmapheresis and continuous renal replacement therapy successfully: a case report

Self-induced poisoning with chemicals is one of the most commonly used suicide methods. Suicide attempts using massive pure sodium ferrocyanide and methanol are rare. This article discusses the management of acute intentional self-poisoning using sodium ferrocyanide and methanol. We present a case of acute self-induced poisoning using sodium ferrocyanide and methanol admitted to our hospital 2 hours after ingestion. He was deeply unconscious and unresponsive to painful stimuli. The laboratory findings showed acute kidney injury and severe metabolic acidosis. We took effective measures including endotracheal intubation and mechanical ventilation to ensure the vital signs were stable. Subsequently, we treated the patient using gastric lavage, bicarbonate, ethanol, plasmapheresis (plasma exchange), and continuous renal replacement therapy (CRRT) successfully. He gradually recovered from poisoning and was discharged without abnormalities on the 6th day. Follow-up for 3 months revealed no sequelae. Blood purification including plasmapheresis and CRRT is an effective method to scavenge toxicants from the body for acute self-poisoning with sodium ferrocyanide and methanol. Treatment strategies in the management of poisoning, multiple factors including the removal efficiency of toxin, the protection of vital organs, and the maintenance of homeostasis must be considered.

Hemodiafiltration efficacy in treatment of methanol and ethylene glycol poisoning in a 2-year-old girl

INTRODUCTION

Every year about 2.4 million people in USA are exposed to toxic substances. Many of them are children below 6 years of age. Majority of poisonings in children are incidental and related to household products including for example drugs, cleaning products or antifreeze products. Antifreeze solutions contain ethylene glycol and methanol. Treatment of these toxic substances involves ethanol administration, fomepizole, hemodialysis and correction of metabolic acidosis.

PURPOSE

The aim of the study was to check the efficacy of continuous venovenous hemodiagiltration in intoxication with ethylene glycol and methanol.

MATERIAL AND METHODS

One year and 7 months old girl after intoxication with ethylene glycol and methanol was treated with continuous venovenous hemodiafiltration instead of hemodialysis because of technical problems (circulatory instability).

RESULTS

Intravenous ethanol infusion with hemodialtration resulted in rapid elimination of methanol from the body and significantly reduced blood ethylene glycol level.

CONCLUSIONS

Continuous venovenous hemodiafiltration can be helpful in treatment of ethylene glycol and methanol intoxication.