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

BACKGROUND: Acute methanol intoxication, whether unintentional or deliberate, necessitates prompt intervention to prevent severe morbidity and mortality. Homemade alcoholic beverages are a frequent source of such poisoning. This retrospective analysis examined two outbreaks of methanol intoxication in Saudi Arabia. It investigated the clinical presentation, implemented management strategies, and any lasting complications (sequelae) associated with these cases. The aim was to assess the potential impact of different treatment modalities and the timeliness of their initiation on patient outcomes. METHODS: This was a retrospective case series of methanol poisoning cases which presented to the adult emergency department (ED) at King Abdulaziz Medical City (KAMC) in Riyadh, Saudi Arabia. There were two separate outbreaks in the city, the first one was from September 1 to September 10, 2020 and the second one was from May 14 to May 20, 2021. Electronic charts were reviewed, and data were extracted to previously prepared data extraction sheets. RESULT: From the 22 patients who arrived in the ED alive, the most common complaints were nausea or vomiting followed by altered level of consciousness. About 9% from the patient were hypotensive, 36% were tachycardic, 41% were tachypneic and 4% were having SpO2 < 94%. Brain CT was abnormal in 6 patients. Vision impairment was the most common sequalae of methanol poisoning (7 out of 12 patients who were assessed by ophthalmologist, 58%). When the patients were divided based on severity (mild, moderate, severe), nausea or vomiting and loss of consciousness were the most common complaints among the moderate group while loss of consciousness predominated in the severe group. Two patients presented with low blood pressure and were in the sever group. The severe group had a mean Glasgow Coma Scale (GCS) of 8. Most of the patients in the severity groups underwent the same management apart from those who died or deposited. Eight patients in the severe group had to be intubated. CONCLUSION: This study demonstrates the multifaceted clinical presentation of methanol poisoning, culminating in a 17.4% mortality rate. Notably, our findings emphasize the critical role of prompt diagnosis and swift initiation of combined fomepizole therapy and hemodialysis in mitigating mortality and minimizing the potential for chronic visual sequelae associated with methanol poisoning.

The Role of Optic Nerve Diffusion Restriction on Visual Prognosis in Methanol Poisoning.

The aim of this study was to investigate the role of optic nerve diffusion status on cranio-orbital magnetic resonance imaging (MRI) in predicting visual prognosis in cases of methanol intoxication. Diffusion-weighted imaging (DWI) from 16 eyes of eight patients who were admitted to our clinic due to methanol intoxication was analysed retrospectively. The relationship between clinical and laboratory findings, treatment regimen, visual prognosis, and imaging findings was investigated. Diffusion restriction (DR) of the optic nerve on DWI was observed in seven (43%) eyes. Regardless of the clinical and laboratory characteristics and treatment regimen, visual acuity (VA) improved in eyes in which restricted diffusion regressed over the follow-up period. DWI of the optic nerve during the acute phase of methanol poisoning may provide prognostically important data. Improvement of DR during follow-up may be an indicator of an increase in VA.

Awareness raising and dealing with methanol poisoning based on effective strategies.

Intoxication with methanol most commonly occurs as a consequence of ingesting, inhaling, or coming into contact with formulations that include methanol as a base. Clinical manifestations of methanol poisoning include suppression of the central nervous system, gastrointestinal symptoms, and decompensated metabolic acidosis, which is associated with impaired vision and either early or late blindness within 0.5-4 h after ingestion. After ingestion, methanol concentrations in the blood that are greater than 50 mg/dl should raise some concern. Ingested methanol is typically digested by alcohol dehydrogenase (ADH), and it is subsequently redistributed to the body's water to attain a volume distribution that is about equivalent to 0.77 L/kg. Moreover, it is removed from the body as its natural, unchanged parent molecules. Due to the fact that methanol poisoning is relatively uncommon but frequently involves a large number of victims at the same time, this type of incident occupies a special position in the field of clinical toxicology. The beginning of the COVID-19 pandemic has resulted in an increase in erroneous assumptions regarding the preventative capability of methanol in comparison to viral infection. More than 1000 Iranians fell ill, and more than 300 of them passed away in March of this year after they consumed methanol in the expectation that it would protect them from a new coronavirus. The Atlanta epidemic, which involved 323 individuals and resulted in the deaths of 41, is one example of mass poisoning. Another example is the Kristiansand outbreak, which involved 70 people and resulted in the deaths of three. In 2003, the AAPCC received reports of more than one thousand pediatric exposures. Since methanol poisoning is associated with high mortality rates, it is vital that the condition be addressed seriously and managed as quickly as feasible. The objective of this review was to raise awareness about the mechanism and metabolism of methanol toxicity, the introduction of therapeutic interventions such as gastrointestinal decontamination and methanol metabolism inhibition, the correction of metabolic disturbances, and the establishment of novel diagnostic/screening nanoparticle-based strategies for methanol poisoning such as the discovery of ADH inhibitors as well as the detection of the adulteration of alcoholic drinks by nanoparticles in order to prevent methanol poisoning. In conclusion, increasing warnings and knowledge about clinical manifestations, medical interventions, and novel strategies for methanol poisoning probably results in a decrease in the death load.

Ocular Manifestations After Acute Methanol Poisoning.

Acute methanol poisoning is first and foremost life-threatening. Otherwise, functional prognosis is mainly based on ocular impairment. In this case series we aimed to describe the ocular manifestations after acute methanol poisoning during an outbreak in Tunisia. The data from 21 patients (41 eyes) were analysed. All patients underwent a complete ophthalmological examination including visual fields, colour vision test and optical coherence tomography with evaluation of the retinal nerve fibre layer. Patients were classified into two groups. Group 1 included patients with visual symptoms and group 2 included patients with no visual symptoms. Ocular abnormalities were seen in 81.8% of patients with ocular symptoms. They included: optic neuropathy in 7 patients (63.6%); central retinal artery occlusion in 1 patient (9.1%); and central serous chorioretinopathy in 1 patient (9.1%). Mean blood methanol levels were significantly higher in patients without ocular symptoms (p = .03).

Severe visual loss caused by inhalational methanol poisoning in fireworks production: A report on 3 cases.

BACKGROUND: Workers in fireworks production are mainly at risk for explosion injury. However, there are few reports on the consequences of methanol poisoning in fireworks laborers. CASE PRESENTATION: We report on three patients with visual loss caused by inhalation exposure to high concentrations of methanol, who were engaged in the granulation process of the fireworks manufacturing industry. They presented with severe metabolic acidosis and visual impairments, accompanied by headache, chest tightness, shortness of breath, dizziness, and vomiting. All were diagnosed with acute methanol poisoning. One patient developed bilateral blindness and two patients improved after timely hemodialysis treatment. CONCLUSIONS: These case reports emphasize the risk of methanol poisoning in the fireworks industry or other factories using commercial alcohol with high methanol content. Early hemodialysis intervention and metabolic acidosis correction are crucial for rescuing visual impairment caused by methanol exposure. Awareness and supervision of commercial alcohol use are indispensable for similar industrial processes.

Methanol Poisoning as an Acute Toxicological Basal Ganglia Lesion Model: Evidence from Brain Volumetry and Cognition.

BACKGROUND: Acute methanol poisoning leads to optic neuropathy and necrotic lesions of basal ganglia (BG) and subcortical white matter. Survivors of methanol poisoning exhibit long-term executive and memory deficits. Associations between brain volumetry parameters and cognitive sequelae of methanol poisoning are not known. The aim of our study was to identify long-term associations between the cognitive performance of survivors of methanol poisoning and the volume of the brain structures that are selectively vulnerable to methanol. METHODS: We conducted a cross-sectional follow-up study on a sample of patients (n = 33, age 50 ± 14 years, 82% males) who survived acute methanol poisoning during methanol mass poisoning outbreak from September 2012 till January 2013 in the Czech Republic. A battery of neuropsychological tests and brain magnetic resonance imaging were included in the clinical examination protocol. Specific brain structures (putamen, globus pallidus, nucleus caudatus, and frontal white matter) were selected as regions of interest, and their volumes were estimated using the MorphoBox prototype software. RESULTS: In robust multiple regression models, sustained visual attention performance (as assessed by Trail Making Test and Prague Stroop Test) was positively associated with BG structures and frontal white matter volumes (Wald = 9.03 to 85.50, p < 0.01), sensitivity to interference (as assessed by Frontal Battery Assessment) was negatively associated with frontal white matter volume (Wald = 35.44 to 42.25, p < 0.001), and motor performance (as assessed by Finger Tapping Test) was positively associated with globus pallidus and frontal white matter volumes (Wald = 9.66 to 13.29, p < 0.01). CONCLUSIONS: Our results demonstrate that smaller volumes of elements of BG-thalamocortical circuitry, namely the BG and frontal white matter, relate to attention and motor performance in methanol poisoning from a long-term perspective. Disruption of those functional circuits may underlie specific cognitive deficits observed in methanol poisoning.

Clinical analysis of severe visual loss caused by inhalational methanol poisoning in a chronic process with acute onset:a retrospective clinical analysis.

BACKGROUND: To analyze the clinical features and prognosis of the visual loss resulted from inhalational methanol poisoning in 8 Chinese patients. METHODS: Eight consecutive patients seen at the Beijing Tongren Hospital of Capital Medical University, Beijing, China between January 2003 to August 2017, with complains of vision loss in both eyes, identified as inhalational methanol poisoning. Detailed medical history was extracted. All patients underwent optic nerve and brain magnetic resonance imaging (MRI) scan, laboratory tests, and visual function analysis. Treatment protocols were large dosage of methylprednisolone and B vitamins over 3 months. Patients were seen at 3-month intervals until a year. RESULTS: Eight patients with optic neuropathy caused by inhalation toxicity of methanol were under observation, whose methanol-contact time spans were form 4 days to 5 years for occupational exposure. All the patients had acute onset, transient systemic symptoms on early stage, both eyes involved with severe visual impairment (visual acuity 0.1 or even worse). Retrobulbar optic nerves (ONs) were the major sites involved. Optic nerve MRI scan showed increased signal of bilateral ONs in the orbit and the canal parts, with enhancement. After treatment, the visual function of these patients got improved in different degree in a year follow-up, but not satisfactorily. CONCLUSIONS: Inhalational methanol toxicity may lead to serious damage to ON in a process of chronic intoxication with acute attack, and with poor prognosis.

Severe methanol poisoning with neurological sequelae: implications for diagnosis and management.

A 22-year-old woman presented with methanol toxicity manifesting as headache, reduced conscious state and visual change after consuming home-made grappa. She progressed to a coma with fixed mydriasis and severe acidaemia (pH 6.55). She was treated with empirical antidote administration (intravenous ethanol) and enhanced elimination through haemodialysis. She survived despite her delayed presentation but developed significant neurological sequelae, including visual impairment. We provide an overview of key elements of diagnosis and recent updates in treatment recommendations.

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.

A novel bedside diagnostic test for methanol poisoning using dry chemistry for formate.

BACKGROUND: The standard diagnostic approach to methanol poisoning is chromatographic measurement of methanol on centrally placed stationary equipment. Methanol poisoning in places where such equipment is unavailable is thus often not diagnosed. Methanol is metabolized to a toxic metabolite, formate; the presence of this compound indicates methanol poisoning. We have developed an enzymatic test for formate and modified it into a portable dry chemistry system that could be used anywhere. METHODS: The method consists of two enzymatic steps: Formation of NADH from NAD by formate dehydrogenase, and subsequent use of NADH as a reductant of a tetrazolium into a formazan dye that can be quantified photometrically or visually. RESULTS: The photometer gave a good correlation of R(2) = 0.9893 in serum and R(2) = 0.9949 in whole blood, showing an instrumental detection limit of less than 1 mM (4.5 mg/dL). The visual readings showed a correlation of R(2) = 0.8966. Users experienced some difficulty in separating the negative control from the low positives. CONCLUSIONS: We have documented the feasibility of an affordable formate strip test for bedside diagnosis of methanol poisoning and for screening of metabolic acidosis of unknown origin. Visual reading is possible, but a reader will improve reliability at lower levels of formate. Future studies are necessary to study the sensitivity and specificity towards other causes of metabolic acidosis and other acids present in human blood.

Diffusion-weighted imaging in methanol poisoning: beyond the lentiform fork sign.

INTRODUCTION: Methanol poisoning is a life-threatening emergency, in which the presence of a lentiform fork sign on magnetic resonance imaging, although not exclusive to methanol poisoning, can be of diagnostic assistance. This report highlights the additional value of diffusion-weighted imaging in methanol poisoning. CASE SUMMARY: A 38-year-old man was admitted to the hospital with severe metabolic acidosis, coma and visual disturbances due to methanol poisoning. IMAGES: Initial computed tomography of the brain was unremarkable. However, magnetic resonance imaging revealed the lentiform fork sign, with diffusion-weighted imaging changes in the lentiform nuclei. CONCLUSION: Diffusion-weighted imaging sequences provide additional information compared to traditional magnetic resonance imaging in assessing methanol poisoning. Systematic evaluation is needed to fully understand and utilize the potential predictive value of diffusion-weighted imaging in this context.

Prediction of acute methanol poisoning prognosis using machine learning techniques.

Methanol poisoning is a global public health concern, especially prevalent in developing nations. This study focuses on predicting the severity of methanol intoxication using machine learning techniques, aiming to improve early identification and prognosis assessment. The study, conducted at Loghman Hakim Hospital in Tehran, Iran. The data pertaining to individuals afflicted with methanol poisoning was retrieved retrospectively and divided into training and test groups at a ratio of 70:30. The selected features were then inputted into various machine learning methods. The models were implemented using the Scikit-learn library in the Python programming language. Ultimately, the efficacy of the developed models was assessed through ten-fold cross-validation techniques and specific evaluation criteria, with a confidence level of 95%. A total number of 897 patients were included and divided in three groups including without sequel (n = 573), with sequel (n = 234), and patients who died (n = 90). The two-step feature selection was yielded 43 features in first step and 23 features in second step. In best model (Gradient Boosting Classifier) test dataset metric by 32 features younger age, higher methanol ingestion, respiratory symptoms, lower GCS scores, type of visual symptom, duration of therapeutic intervention, ICU admission, and elevated CPK levels were among the most important features predicting the prognosis of methanol poisoning. The Gradient Boosting Classifier demonstrated the highest predictive capability, achieving AUC values of 0.947 and 0.943 in the test dataset with 43 and 23 features, respectively. This research introduces a machine learning-driven prognostic model for methanol poisoning, demonstrating superior predictive capabilities compared to traditional statistical methods. The identified features provide valuable insights for early intervention and personalized treatment strategies.

Real-world safety and effectiveness of intravenous fomepizole in patients with ethylene glycol and methanol poisoning in Japan: results of a 7-year post-marketing surveillance study.

BACKGROUND: Fomepizole is a competitive alcohol dehydrogenase inhibitor used for the treatment of ethylene glycol and methanol poisoning. We evaluated the safety and effectiveness of fomepizole in patients with ethylene glycol or methanol poisoning in Japan. RESEARCH DESIGN AND METHODS: This retrospective post-marketing surveillance study conducted in Japan registered patients who received fomepizole intravenous infusion per the package insert (January 2015-June 2022). Endpoints included adverse drug reactions/infections (ADRs), arterial blood pH, and treatment outcomes. RESULTS: Of 147 patients registered (91 institutions), 131 and 126 were included in the safety and effectiveness analysis set, respectively. Mean age was 43.6 years, and 66.4% were male. Mean time from poison ingestion to treatment was 15.1 hours; 66.4% received concomitant hemodialysis. No serious ADRs were reported. ADRs were reported in seven patients; the most-reported ADR was vomiting (2.3%). Seven patients died, 105 survived without sequelae, and 19 survived with sequelae. Most common sequelae were renal failure or renal dysfunction. Mean arterial blood pH increased to 7.4 by 4 hours of treatment, remaining stable for 24 hours post-treatment. CONCLUSIONS: Fomepizole is well tolerated and helps improve clinical outcomes in patients with ethylene glycol or methanol poisoning in Japan. TRIAL REGISTRATION: Japanese Pharmaceutical Information Center (JapicCTI-152817).

Male- and female-specific microRNA expression patterns in a mouse model of methanol poisoning.

The aims of this study were to determine the miRNAs involved in the methanol poisoning, and identify the male- and female-specific miRNA expression patterns in mice. Methanol was applied orally at the doses of 4 g/kg and 8 g/kg to induce mild and severe methanol poisoning in Balb/c mice. miRNA expression levels were detected at 3 different time periods (30, 60, and 180 min) following methanol exposure. miRNA expression profiles were determined using the high-throughput Fluidigm BioMark real-time PCR. We observed that serum miR-206 expression in male mice and miR-6357 expression in female mice could be an indicator of methanol poisoning. miR-9-3p downregulation and miR-1187 upregulation could be important for liver tissue. miR-3106-5p and miR-133a-5p upregulations and miR-122-3p downregulation could be poison biomarkers for ocular tissue in male mice. However, miR-194-5p downregulation could be a biomarker for ocular tissue in female mice. miR-122-5p and miR-124-3p downregulations and miR-499a-5p upregulation appeared to be important for kidney tissue in male mice. miR-543 and miR-6342 upregulations could be potential candidate biomarkers for kidney tissue in female mice. Our study is the first to report that differential miRNA expressions are involved in blood and tissues in male and female mice after methanol treatment.

Methanol toxicity in a pediatric patient treated with fomepizole and hemodialysis.

Methanol toxicity is an important cause of toxic alcohol exposure resulting in morbidity and mortality in both adult and pediatric populations. Methanol is metabolized into formaldehyde and formic acid: toxic metabolites that can cause altered mental status, visual disturbances, multisystem organ failure, and death. Recognition of methanol intoxication and rapid treatment are critical for the prevention of long-term sequelae. We present the case of a 16-year-old male with a past medical history of depression who intentionally ingested windshield wiper fluid containing methanol. Based on the patient's osmolal gap, he was estimated to have a serum methanol level of 374 mg/dL; a send-out laboratory measurement later revealed a serum methanol level of 436 mg/dL. Therapy included two hemodialysis treatments as well as fomepizole and supportive care. The patient recovered remarkably with no long-term sequelae. This case demonstrates the effectiveness of swift recognition and treatment of methanol ingestion. Optimization of methods of measuring serum methanol and evidence-based guidelines for therapy are needed to improve the care of patients with methanol intoxication.

Corrigendum: Case report: early recognition, treatment, and occupational safety protection are crucial for methanol toxicity.

[This corrects the article DOI: 10.3389/fmed.2022.918812.].

Methanol poisoning during the COVID-19 pandemic in Iran: A retrospective cross-sectional study of clinical, laboratory, and brain imaging characteristics and outcomes.

Objective: To evaluate the frequency and significance of brain imaging findings in methanol poisoning patients and to propose a criterion for prioritizing brain imaging. Methods: We retrospectively reviewed the data of 306 patients (286 men and 34 women, mean age 32.10 ± 9.9 years) with confirmed methanol poisoning who were admitted to two hospitals in Iran during the COVID-19 pandemic. We analyzed their demographic, clinical, laboratory, and brain imaging data. Results: The main brain computed tomography (CT) scan findings were hypodensity in the putamen (11.1%), cerebellar nuclei (8.2%), diffuse cerebral edema (7.5%), and intracranial hemorrhage (ICH; 1.6%). These findings were associated with blood pH, Glasgow Coma Scale (GCS), renal failure, bicarbonate, oxygen, carbon dioxide, potassium, and glucose levels (p < 0.05). Poor prognosis was related to blindness, opium addiction, chronic alcohol use, hyperglycemia, and abnormal CT scans (p < 0.001 for all). The most predictive brain imaging findings for poor prognosis were hypodensity in the cerebellar nuclei, diffuse cerebral edema, and ICH. Conclusion: Brain imaging can provide valuable information for the diagnosis and management of methanol poisoning patients. We suggest that patients with severe acidosis, low GCS, low pH, low oxygen saturation, and high glucose levels should undergo brain CT scan as a priority.

Spontaneous Bilateral Basal Ganglia Haemorrhage Secondary to Methanol Poisoning.

Methanol toxicity remains as major problem in the medical field.[1],[2],[3] With its active metabolite, formic acid often leads to severe metabolic acidosis and to some extend brain damaged.[4],[5],[6] We are reporting a case of brain hemorrhage at the right external capsule and left basal ganglia with mass effect and obstructive hydrocephalus in a methanol poisoning patient. A confused 29-year-old gentleman was brought into hospital. Initial investigation showed severe metabolic acidosis with raised anion gap. Initial brain CT scan was normal. Subsequently, serum methanol was reported to be high (112 mg/dL). Intravenous (IV) ethanol 10% was given without any delayed. As there was no improvement in his consciousness level, a repeat brain CT was performed and it showed multiple cerebral hemorrhage with obstructive hydrocephalus. Hence, clinicians should have high index of suspicion for cerebral hemorrhage in a patient with methanol toxicity, who presented with altered mental status and severe metabolic acidosis.

Höffding step and beyond: The impact of visual sensory impairment on cognitive performance in neuropsychological testing of survivors of acute methanol poisoning.

BACKGROUND: Sensory deficits can result in limitations regarding how well neuropsychological test findings can be interpreted. Only a few studies have investigated the influence of vision alteration on neuropsychological tests. In 2012 the Czech Republic experienced mass methanol poisoning. Methanol metabolites cause histotoxic hypoxia to the optic nerve. OBJECTIVE: In the current study, the effect of the toxic damage on the parts of the visual pathway on visual and non-visual neuropsychological measures was investigated using electrophysiological methods (visual evoked potential (VEP) and optical coherence tomography (OCT) with retinal nerve fibre layer (RNFL) thickness measurement. METHODS: 53 individuals who experienced methanol poisoning participated in this research (76% men; ages 24 to 74 years, mean = 43.8±14.6 years; education 11.9±1.4 years). Each participant underwent comprehensive neurological, ophthalmological, and neuropsychological examinations. RESULTS: The results of mixed-effect models revealed significant small to a medium association between the Stroop test weak interference and Grooved Pegboard with the left eye global, nasal and temporal RNFL thickness. Also, medium associations between the Finger Tapping test and the Stroop test weak interference and left eye temporal RNFL, right eye temporal RNFL, and the latency P1 of VEP in the left eye were significant. CONCLUSION: The results of this study found a small to medium association (r = .15- .33; p = .010- .046) between RNFL thickness and cognitive visual test performance. Careful interpretation is suggested regarding results obtained from visual tests of the executive or motor functioning with participants with RNFL decrease or other types of early visual processing damage.

Case Reports Study on Methanol Poisoning in King Abdul Aziz Specialist Hospital, Taif, Saudi Arabia.

Methanol poisoning is a challenging issue due to its inducing acute multiple organ failures, and especially due to a lack of preparedness, available antidotes, and management protocols. The current study presents six cases of methanol poisoning that attended the emergency department of King Abdul Aziz Specialist Hospital, Taif, Saudi Arabia, between March and November 2022. All of the patients suffered from severe metabolic acidosis and visual impairment following the ingestion of homemade alcoholic beverages and colonia. Three patients were comatose, suffered from post-cardiac pulmonary arrest, and, finally, died, while the other three were non-comatose and discharged from the ICU after improvement. Management was based on clinical symptoms and other laboratory findings due to a shortage of methanol level measurement resources. The antidote, fomepizole, was not given to all of the cases due to its deficiency, and ethanol was given only to one patient due to difficulties in administering it without monitoring its concentration. Methanol poisoning and its outbreak provide insights into the dangers of hazardous homemade alcohol and other pharmaceutical preparations that might be adulterated with methanol, particularly to the shortage of suitable diagnostic testing and antidotes in addition to poor resources for management of intoxicated patients in some regions of Saudi Arabia.