Methanol intoxication outbreak in Bogotá, Colombia: a retrospective case series of clinical characteristics, management, and patient outcomes

Methanol intoxication outbreak in Bogotá, Colombia: a retrospective case series of clinical characteristics, management, and patient outcomes | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Methanol intoxication outbreak in Bogotá, Colombia: a retrospective case series of clinical characteristics, management, and patient outcomes Jonathan Alexander Güezguan, Carlos Calderón Franco, Oscar Cujiño Ibarra, and 4 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-9182533/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 4 You are reading this latest preprint version Abstract Background Methanol is a widely used chemical in industrial processes, and it is frequently implicated in cases of toxic alcohol exposure, especially through the consumption of adulterated or illicit liquors. Following voluntary or accidental ingestion, methanol is metabolized to formic acid, which causes severe high-anion-gap metabolic acidosis and cellular hypoxia. Serum methanol concentrations ≥ 20 mg/dL may produce a life-threatening toxicologic emergency characterized by severe metabolic disturbances and multiorgan dysfunction, which may lead to the need for ventilatory or renal support therapy with high mortality. Methods This was a retrospective case series of patients with acute methanol intoxication admitted to the emergency departments of the Central Eastern Healthcare Subnetwork in Bogotá between December 2022 and February 2023. Sociodemographic characteristics, clinical presentation, laboratory variables, and patient outcomes were retrieved from medical records and analyzed descriptively. Patients under 18 years of age and pregnant women were excluded. Results Fifteen patients with methanol intoxication were identified, with a male-to-female ratio of 4:1. The mean age was 54.5 ± 10.3 years. Alcohol consumption was accidental in 85% of cases, and ethanol was co-ingested in 14.2% of cases. Ethanol antidotal therapy was administered to all patients. Severe high anion gap metabolic acidosis was observed with a mean anion gap of 47.8. Thirteen (86.6%) patients required transfer to the intensive care unit, eleven patients (73%) required mechanical ventilation, and ten patients (66%) underwent renal replacement therapy. Nine patients (60%) died during hospitalization, and visual impairment was observed in six patients (40%). Conclusions Methanol intoxication in this series was characterized by high mortality, predominantly affecting middle-aged men, and a substantial requirement for renal and ventilatory support. Early diagnosis and prompt access to antidotal and supportive therapies should be prioritized in clinical settings to improve patient outcomes. Intoxication mortality methanol Intensive Care Unit Introduction Methanol, also known as methyl alcohol or wood alcohol, is a liquid product that is volatile, flammable, and has a slight alcohol odor. It is a common ingredient in many industrial and household products, such as methylamines, ethylene glycol, formaldehyde, solvents, paint removers, cleaning solutions, resins, adhesives, antifreeze, and photographic products ( 1 ). Methanol and its metabolites are toxic once they enter the body. Methanol primarily causes central nervous system depression. However, profound toxicity occurs when it is metabolized through oxidation in the liver, primarily by the alcohol dehydrogenase enzyme (ADH) to formaldehyde and subsequently to formic acid by aldehyde dehydrogenase (ALDH) ( 2 , 3 ). Formic acid —the metabolite of methanol and primary mediator of toxicity—produces clinically significant intoxication when its plasma concentration exceeds 20 mg/dL, leading to the accumulation of formate and the development of a marked high anion gap metabolic acidosis. This metabolic disturbance is directly correlated with the buildup of toxic organic acids in the circulation ( 4 , 5 ). The resulting acidemia facilitates the cellular penetration of formate, further depressing the central nervous system and causing a rapid downward spiral of tissue hypoxia ( 6 ). Additionally, methanol can cause retinal lesions with optic disc hyperemia, edema, and ultimately permanent blindness, as well as ischemic or hemorrhagic lesions in the basal ganglia. These changes are likely to be the result of mitochondrial oxidative phosphorylation inhibition, ultimately resulting in metabolic, cardiovascular, and neurological impairment. Multiorgan involvement, particularly renal and respiratory failure, is highly correlated with mortality ( 7 , 8 ). Intoxications in Colombia are often a consequence of fraudulent use of methanol in illicit alcoholic beverages as a substitute for ethanol or owing to deficiencies in the distillation process, principally among individuals with alcohol use disorder, who may consume methanol-containing products as a substitute for ethanol due to financial constraints or limited access to alcoholic beverages. Another route of exposure is inhalation, leading to accidental poisonings ( 8 ). Methanol intoxication (MI) is a relatively rare problem in our country, although it may be underreported. Reported mortality rates have reached up to 44%, with high morbidity and disabilities among survivors ( 9 , 10 ). As a consequence of the sudden increase in the incidence of MI related to adulterated liquor consumption observed during the New Year's holiday season of 2022, it became necessary to describe the factors related to mortality in the affected patients, which could help identify potential disease-progression determinants and establish early prognosis indicators to guide the implementation of timely interventions, thereby reducing complications, sequelae, and death. The objective of this study was to describe a series of cases of patients treated for MI in Bogota, Colombia, and to contextualize the findings within the existing literature. Methods A retrospective case series study was conducted on patients aged 18 years or older diagnosed with acute MI, who were admitted to the Central Eastern Healthcare Subnetwork of Bogotá, Colombia, between December 2022 and February 2023. This subnetwork comprises five hospitals and sixteen primary healthcare centers serving an urban population. Diagnosis was confirmed by measurement of serum methanol concentrations through spectrophotometric analysis. Patients under 18 years of age and pregnant women were excluded. An Excel (Microsoft ®) spreadsheet was used to collect patients' sociodemographic and clinical data from electronic medical records. Descriptive statistical analysis was performed using Stata version 15.0 (StataCorp, LLC). For quantitative variables, means, percentiles, standard deviation (SD), and variance were calculated, while categorical variables were described using frequency tables. The study protocol for retrospective data collection was reviewed and approved by the research ethics committee of the Central Eastern Healthcare Subnetwork. Results Table 1 summarizes the clinical and sociodemographic characteristics of the hospitalized patients with acute MI. There were 15 laboratory-confirmed cases identified. The male-to-female ratio was 4:1, with an average age of 54.5 ± 10.3 years. Accidental alcohol consumption accounted for 85% of cases, while concomitant ethanol ingestion was present in 14.2% of cases. Prior consumption of other alcoholic beverages was documented in 85.7% of the cases. At admission, mean systolic blood pressure was 123.3 ± 46.6 mmHg, mean diastolic blood pressure was 77.5 mmHg ± 29 mmHg, and mean arterial pressure (MAP) was 92.5 mmHg. The mean heart rate was 82.7 ± 28 bpm, and the mean respiratory rate was 16 ± 6.5 rpm. No febrile episodes were observed (mean temperature 36.1 ± 0.4°C), but there was a decrease in urine output, with a mean of 0.57 mL/kg/h. One patient presented with atrial fibrillation. Altered levels of consciousness were common, with somnolence in 7.1% of cases, unconsciousness in 21.4%, and coma in 35.7%. The most frequent gastrointestinal symptoms were epigastric pain, accompanied by nausea and vomiting (60%). Ocular symptoms included amaurosis (44.4%) and decreased visual acuity (22.2%), with mydriasis being the most frequent ocular sign (64.2%). Other recorded neurological manifestations were syncope (33.3%), intense headache and dizziness in five patients, and seizures in 33.3% of the cases. Laboratory evaluation revealed hyperglycemia (mean glucose 175.5 mg/dL +/- 80.7 mg/dL), hyperkalemia (5.7 ± 6.4 mmol/L), whereas sodium levels remained in the normal range (142.5 ± 6.4 mmol/L). Metabolic acidosis was observed on arterial blood gas analysis (pH: 6.98 ± 0.2; HCO3: 3.2 ± 5.87 mmol/L; pCO2: 27.1 ± 15.5 mm Hg; BE -18.5 ± 13.5). Hyperlactatemia was also frequent, with a mean lactate level of (9.24 mmol/L ± 6.1 mmol/L. Mean osmolarity was 280.6 ± 73.6 mOsm/kg, and a markedly elevated anion gap was observed (47.8 ± 32.5 mmol/L). Evidence of renal impairment was common, with most patients presenting KDIGO stage 2 acute kidney injury (AKI) (mean creatinine 2.19 mg ± 1.2 mg/dL, BUN 16.4 mg/dL). Complications observed in this case series were severe, with 13 patients (86.6%) requiring transfer to the intensive care unit, of whom 11 (78.5%) necessitated MV. Antidotal therapy consisted of ethanol administration, using aguardiente (a locally available distilled alcoholic beverage) as the ethanol source, since fomepizole was not available in the study setting. Ten patients required RRT (66.7%), and the in-hospital mortality rate was 60% (9 of 15 patients). Discussion This study describes a series of 15 cases of MI in Colombia. To our knowledge, this represents the first report of this magnitude in the Latin American context, and occurred within a considerably shorter two-month timeframe compared to previous reports worldwide. This is associated with an outbreak of adulterated alcohol consumption during the 2022 holiday season. Although MI has been widely described, the majority of the reports either correspond to large mass poisoning events or multicenter cohorts for longer periods of time. For example, the study conducted by Galvez et al. in Saudi Arabia included 50 patients over three years, only reporting surviving patients ( 10 ). Moreover, Zakharov described 121 patients involved in a mass MI event in the Czech Republic in 2012 ( 11 ), and in 2020, toxicology centers in the United States reported 603 cases of methanol exposure between 2003 and 2014 ( 12 ). In this Colombian report, in which a considerable number of cases were recorded rapidly, the public health impact when adulterated alcohol enters the distribution chain could be observed. The in-hospital mortality rate in this study was high (60%) compared with 21% reported by Zakharov's cohort ( 11 ). This difference may be attributed to several factors. First, patients in our cohort often presented with severe high-anion gap metabolic acidosis, and severe acidemia is a well-established predictor of mortality in MI since it reflects the accumulation of formate and profound mitochondrial dysfunction ( 13 ). Second, the absence of fomepizole in our setting required the use of ethanol therapy, which could have introduced variability in antidotal administration and monitoring. Additionally, delayed consultation of emergency services and the socioeconomic vulnerability of the affected population may have further contributed to the severity of clinical presentation. In contrast, a portion of the patients recruited in the Czech Republic study were prospectively enrolled, allowing for early treatment measures such as fomepizole, ethanol, and hemodialysis; this could have impacted the mortality rate observed in that study. Consistent with previous studies, high rates of organ failure were observed, requiring advanced organ support. Most patients required admission to the ICU, MV, and RRT. Similar findings were reported by Thongprayoon et al., who analyzed a national database of hospitalized patients with MI in the United States between 2003 and 2014, and described AKI in 22.4% of cases, along with an association between AKI and increased risk of multiorgan failure and in-hospital mortality ( 13 ). This pattern may be related to AKI being a causal factor in severe metabolic acidemia, therefore impacting patient outcomes. The Sequential Organ Failure Assessment (SOFA) score has been proposed as a useful prognostic tool in MI ( 14 ). Unfortunately, our study lacked this data, since not all patients underwent the needed laboratory tests to calculate the score. In relation to this, Sharif et al. studied 37 patients with accidental MI in Saudi Arabia and found that the SOFA score had an area under the curve of 0.95% for predicting unfavorable outcomes ( 14 ). Therefore, the SOFA score could be used to evaluate patients at risk of deterioration, determine ICU admission, and initiate early supportive therapies. However, the SOFA score has the drawback of being composed of variables that may not be altered upon initial assessment. Another factor related to poor outcomes is a prolonged latency period between methanol exposure and initiation of treatment, as suggested by Yayci et al. in a study of fatal MI cases in Turkey ( 15 ). In our case, we were unable to determine the time interval between ingestion and treatment due to unreliable data obtained from patient interviews and the lack of family members present during emergency evaluation. The population most frequently affected by MI in our study was middle-aged men, contrasting with Yaycy’s report, which indicated a younger age range between 36 and 40 years. However, that report classified ages into quintiles ( 15 ). In both studies, the majority of patients were chronic alcoholics who resorted to consuming methanol due to its lower cost. In our study, accidental oral consumption accounted for 85% of cases, which is in line with other series, with a lower percentage involving suicidal intent ( 16 ). In our cohort, laboratory findings demonstrated severe metabolic acidosis, with an elevated anion gap and hyperlactatemia. However, when comparing these results with previously published series, such as that of Noor et al., in which fatal cases presented even more extreme levels of acidemia, anion gap, and lactate, it is noteworthy that mortality in our study remained high despite apparently less severe metabolic disturbances ( 9 ). This finding suggests that the magnitude of acidemia and tissue hypoperfusion, at least as measured by these variables, may not by itself fully explain the high mortality observed. Nevertheless, this interpretation should be made with caution, as the lack of information on risk scores, therapeutic interventions received, and the availability of fomepizole at the participating centers limits the ability to make valid comparisons and draw definitive conclusions. Strengths of this study include providing information to identify patients at increased risk, which may prevent complications and theoretically reduce mortality by allowing for early interventions. Most studies on MI are observational and consist of case reports and case series. Other published studies utilize national databases and retrospective analysis of accidental or self-inflicted MI reports. These studies focus on the involvement of a single organ, so this case series contributes to the understanding of local epidemiology and raises awareness among medical teams and government entities about the importance of providing adequate therapy availability and working to prevent the production of adulterated liquor. Limitations of the study include its retrospective nature, the lack of SOFA scores at admission, the inability to determine the time from ingestion to treatment, the socioeconomic vulnerability of the population, which could potentially alter the expected mortality rate, the inability to determine the treatment received by all patients, and the inability to conduct follow-ups on surviving patients to evaluate their medium- and long-term sequelae. Conclusions MI in this series was characterized by high mortality and a frequent necessity of MV and RRT. The patients experienced intoxication in a short period of time; this temporal clustering of the cases suggests an outbreak linked to adulterated liquor and its fraudulent distribution. These findings accentuate the severe clinical impact of methanol intoxication and underscore the importance of early diagnosis in the emergency department and timely access to adequate therapy to improve patients’ outcomes. In addition, they support the need for preventive strategies to reduce the risk of future outbreaks. Abbreviations ADH:Alcohol Dehydrogenase enzyme, VM: Mechanical Ventilation, ICU Intensive Care Unit, mg/dL milligrams per deciliter, mmHg millimeters of mercury, MAP Mean Arterial Pressure, BPM Beats per Minute, respirations per minute, mmol/L millimoles per liter, °C degrees Celsius, SD= Standard deviation, BUN= Blood nitrogen urea, RRT= Renal replacement therapy, MI= Methanol intoxication. Declarations Ethics approval and consent to participate This study was conducted in accordance with the ethical principles outlined in the WMA Declaration of Helsinki. The study protocol was reviewed and approved by the Research Ethics Committee of the Central Eastern Healthcare Subnetwork, Bogotá, Colombia. Given the retrospective design and use of anonymized data, the requirement for informed consent was waived by the committee. Consent for publication: Not applicable Availability of data and materials: The datasets used and analyzed during the current study are not publicly available due to institutional and patient privacy restrictions, but are available from the corresponding author on reasonable request. Competing interests: The authors declare that they have no competing interests. Funding: The authors received no specific funding for this work. Authors Contributions JG: Original idea, study design, data analysis, manuscript writing. CC: Statistical analysis and interpretation of data, literature review. OC: Data source search, database parameterization, patient recruitment, and project writing for the healthcare center. AM: Literature review, introduction and discussion writing, project writing for the ethics committee. DC: Overall responsibility, editing, supervision, discussion, and conclusion writing, and approval of the final version. GO: Overall responsibility, editing, supervision, discussion, and conclusion writing, and approval of the final version. MG: Overall responsibility, editing, supervision, discussion, and conclusion writing, and approval of the final version. Acknowledgments: We would like to thank the Central-Eastern Integrated Healthcare Subnetwork of Bogotá for providing the data and enabling the development of this research. References Litovitz T. The alcohols: ethanol, methanol, isopropanol, ethylene glycol. Pediatr Clin North Am. 1986 Apr;33(2):311–23. doi:10.1016/s0031-3955(16)35004-0 PubMed PMID: 2870460. Dudka J, Burdan F, Madej B, Szumilo J, Tokarska E, Korobowicz A, et al. Effect of selected alcohol dehydrogenase inhibitors on the human heart lactate dehydrogenase activity--an in vitro study. Acta Physiol Hung. 2004;91(3–4):235–41. doi:10.1556/APhysiol.91.2004.3-4.7 PubMed PMID: 16438117. Karayel F, Turan AA, Sav A, Pakis I, Akyildiz EU, Ersoy G. Methanol intoxication: pathological changes of central nervous system (17 cases). Am J Forensic Med Pathol. 2010 Mar;31(1):34–6. doi:10.1097/PAF.0b013e3181c160d9 PubMed PMID: 20010293. Aabakken L, Enger E, Jacobsen D, Strømme JH. [Metabolic acidosis--a diagnostic challenge]. Tidsskr Nor Laegeforen. 1994 Jan 30;114(3):331–4. PubMed PMID: 8191432. Zuba D, Piekoszewski W, Pach J, Winnik L, Parczewski A. Concentration of ethanol and other volatile compounds in the blood of acutely poisoned alcoholics. Alcohol. 2002 Jan;26(1):17–22. doi:10.1016/s0741-8329(01)00186-0 PubMed PMID: 11958942. Zuba D, Piekoszewski W, Pach J, Winnik L, Parczewski A. Concentration of ethanol and other volatile compounds in the blood of acutely poisoned alcoholics. Alcohol. 2002 Jan;26(1):17–22. doi:10.1016/s0741-8329(01)00186-0 PubMed PMID: 11958942. Nemeguén Arias CE, Romero C, La Rota G. Intoxicación por metanol. Acta Neurol Colomb. 2025 Jun 24;41(2). doi:10.22379/anc.v41i2.1878 Figuerola B, Mendoza A, Roca M, Lacorzana J. Severe visual loss by inhalation of methanol. Rom J Ophthalmol. 2021;65(2):176–9. doi:10.22336/rjo.2021.34 PubMed PMID: 34179584; PubMed Central PMCID: PMC8207856. Md Noor J, Hawari R, Mokhtar MF, Yussof SJ, Chew N, Norzan NA, et al. Methanol outbreak: a Malaysian tertiary hospital experience. Int J Emerg Med. 2020 Feb 7;13(1):6. doi:10.1186/s12245-020-0264-5 PubMed PMID: 32028888; PubMed Central PMCID: PMC7006424. Galvez-Ruiz A, Elkhamary SM, Asghar N, Bosley TM. Visual and neurologic sequelae of methanol poisoning in Saudi Arabia. Saudi Med J. 2015 May;36(5):568–74. doi:10.15537/smj.2015.5.11142 PubMed PMID: 25935177; PubMed Central PMCID: PMC4436753. Zakharov S, Pelclova D, Urban P, Navratil T, Diblik P, Kuthan P, et al. Czech mass methanol outbreak 2012: epidemiology, challenges and clinical features. Clin Toxicol (Phila). 2014 Dec;52(10):1013–24. doi:10.3109/15563650.2014.974106 PubMed PMID: 25345388. Kaewput W, Thongprayoon C, Petnak T, Chewcharat A, Boonpheng B, Bathini T, et al. Inpatient Burden and Mortality of Methanol Intoxication in the United States. Am J Med Sci. 2021 Jan;361(1):69–74. doi:10.1016/j.amjms.2020.08.014 PubMed PMID: 32958166. Thongprayoon C, Petnak T, Kaewput W, Mao MA, Boonpheng B, Bathini T, et al. Acute kidney injury in hospitalized patients with methanol intoxication: National Inpatient Sample 2003-2014. Hosp Pract (1995). 2021 Aug;49(3):203–8. doi:10.1080/21548331.2021.1882239 PubMed PMID: 33496631. Sharif AF, AlAmeer MR, AlSubaie DS, Alarfaj NH, AlDawsari MK, AlAslai KM, et al. Predictors of poor outcomes among patients of acute methanol intoxication with particular reference to Sequential Organ Failure Assessment (SOFA) score. Environ Sci Pollut Res Int. 2021 Nov;28(43):60511–25. doi:10.1007/s11356-021-14998-w PubMed PMID: 34156622. Yayci N, Ağritmiş H, Turla A, Koç S. Fatalities due to methyl alcohol intoxication in Turkey: an 8-year study. Forensic Sci Int. 2003 Jan 9;131(1):36–41. doi:10.1016/s0379-0738(02)00376-6 PubMed PMID: 12505469. Chien WC, Chung CH, Lin CH, Lai CH. A nationwide evidence-based study of factors associated with hospitalisations due to unintentional poisoning and poisoning mortality in Taiwan. Int J Inj Contr Saf Promot. 2013;20(3):295–301. doi:10.1080/17457300.2012.724689 PubMed PMID: 23003103. Table Table 1. Sociodemographic, clinical, and laboratory characteristics of patients in the cohort. Sociodemographic Characteristics n=15 Age (SD) 54.5 (10.3) Male (%) Female (%) Exposure Mechanism 12 (80) 3 (20) Accidental (%) 12 (80) Commercial beverages (Ethanol) (%) 2 (13.3) Any combination (%) 12 (85.7) Clinical Presentation Systolic blood pressure mm Hg (SD) 123.4 (46.6) Diastolic blood pressure mm Hg (SD) 77.5 (29) Mean arterial pressure mm Hg (SD) 92.5 (34.6) Heart rate bpm (SD) 82.7 (28) Respiratory rate rpm (SD) 16.0 (6.55) Temperature (SD) 36.1 (0.4) Urine output (SD) 0.57 (0.66) Arrhythmias Ventricular fibrillation (%) 1 (6.6) Level of Consciousness Drowsiness (%) 1 (6.6) Unconscious (%) 3 (20) Coma (%) 5 (33.3) Gastrointestinal manifestations Epigastric pain, nausea, and emesis (%) 9 (60) Ocular manifestations Amaurosis (%) 4 (26.6) Decreased visual acuity (%) 2 (13.3) Myosis (%) 1 (6.6) Mydriasis (%) 9 (60) Anisocoria (%) 1 (6.6) Neurological Manifestations Severe headache (%) 3 (20) Vertigo (%) 3 (20) Syncope (%) 4 (26.6) Seizures (%) 4 (26.6) Ataxia (%) 2 (13.3) Laboratory findings Glycemia mg/dl (SD) 174.4 (80.7) Na mmol/L (SD) 142.5 (6.4) K mmol/L (SD) 5.7 (1.7) Cl mmol/L (SD) 101.6 (4.8) pH (SD) 6.98 (0.20) PaO2 mm Hg (SD) 154.6 (99.8) pCO2 mm Hg (SD) 27.16 (15.5) HCO3 mEq (SD) 3.2 (5.87) Lactate mmol/L (SD) 9.24 (6.1) Osmolarity mmol/L (SD) 280.6 (73.6) Anion GAP mmol/L (SD) 47.8 (32.5) BUN mg/dL (SD) 16.4 (8.3) Creatinine mg/dL (SD) 2.19 (1.2) Base excess (SD) -18.5 (13.5) Hospitalization course and outcomes ICU admission (%) 13 (86.6) Need for mechanical ventilation (%) 11 (73.3) RRT requirement (%) 10 (66.6) Mortality (%) 9 (60) Table legends Table 1. Sociodemographic and clinical characteristics of patients with methanol intoxication (n = 15). SD = Standard deviation, bpm = beats per minute, rpm = respirations per minute, BUN = Blood nitrogen urea, ICU = Intensive care unit, RRT = Renal replacement therapy. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Under Review Version 1 posted Reviewers invited by journal 22 Apr, 2026 Editor assigned by journal 25 Mar, 2026 Submission checks completed at journal 25 Mar, 2026 First submitted to journal 20 Mar, 2026 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-9182533","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":631066538,"identity":"451fb4c5-f623-45ad-8470-ee7935e1c0a0","order_by":0,"name":"Jonathan Alexander Güezguan","email":"data:image/png;base64,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","orcid":"","institution":"Subred integrada de servicios de salud Centro Oriente E.S.E, Bogotá, Colombia","correspondingAuthor":true,"prefix":"","firstName":"Jonathan","middleName":"Alexander","lastName":"Güezguan","suffix":""},{"id":631066539,"identity":"810b2d9a-3e51-4f6d-aeb5-93fc844b8d9c","order_by":1,"name":"Carlos Calderón Franco","email":"","orcid":"","institution":"Subred integrada de servicios de salud Centro Oriente E.S.E, Bogotá, Colombia","correspondingAuthor":false,"prefix":"","firstName":"Carlos","middleName":"Calderón","lastName":"Franco","suffix":""},{"id":631066540,"identity":"30581084-1a0c-491e-a680-7276eba891ba","order_by":2,"name":"Oscar Cujiño Ibarra","email":"","orcid":"","institution":"Subred integrada de servicios de salud Centro Oriente E.S.E, Bogotá, Colombia","correspondingAuthor":false,"prefix":"","firstName":"Oscar","middleName":"Cujiño","lastName":"Ibarra","suffix":""},{"id":631066541,"identity":"cbe97f12-447b-4167-8d73-0a7ed489105a","order_by":3,"name":"Arlen Márquez Galindo","email":"","orcid":"","institution":"Subred integrada de servicios de salud Centro Oriente E.S.E, Bogotá, Colombia","correspondingAuthor":false,"prefix":"","firstName":"Arlen","middleName":"Márquez","lastName":"Galindo","suffix":""},{"id":631066542,"identity":"776c587d-79f5-45fb-b143-bfc6c46c4b2a","order_by":4,"name":"Daniel Castro Cadena","email":"","orcid":"","institution":"Grupo de Investigación en Epidemiología Clínica de Colombia (GRECO)","correspondingAuthor":false,"prefix":"","firstName":"Daniel","middleName":"Castro","lastName":"Cadena","suffix":""},{"id":631066543,"identity":"f2665021-adec-4bd1-9423-7d0d39e8b14b","order_by":5,"name":"Guillermo Ortiz Ruiz","email":"","orcid":"","institution":"Subred integrada de servicios de salud Centro Oriente E.S.E, Bogotá, Colombia","correspondingAuthor":false,"prefix":"","firstName":"Guillermo","middleName":"Ortiz","lastName":"Ruiz","suffix":""},{"id":631066551,"identity":"1ca66626-4af3-46a6-909e-e018bd1d1239","order_by":6,"name":"Manuel Garay Fernández","email":"","orcid":"","institution":"Subred integrada de servicios de salud Centro Oriente E.S.E, Bogotá, Colombia","correspondingAuthor":false,"prefix":"","firstName":"Manuel","middleName":"Garay","lastName":"Fernández","suffix":""}],"badges":[],"createdAt":"2026-03-21 01:38:44","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-9182533/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-9182533/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":108205423,"identity":"dfdb9451-1d54-40fb-95b6-139d0440f1f0","added_by":"auto","created_at":"2026-04-30 12:41:12","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":230590,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-9182533/v1/4ed0a68c-5536-4531-9983-aa5473b75a55.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Methanol intoxication outbreak in Bogotá, Colombia: a retrospective case series of clinical characteristics, management, and patient outcomes","fulltext":[{"header":"Introduction","content":"\u003cp\u003eMethanol, also known as methyl alcohol or wood alcohol, is a liquid product that is volatile, flammable, and has a slight alcohol odor. It is a common ingredient in many industrial and household products, such as methylamines, ethylene glycol, formaldehyde, solvents, paint removers, cleaning solutions, resins, adhesives, antifreeze, and photographic products (\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e). Methanol and its metabolites are toxic once they enter the body. Methanol primarily causes central nervous system depression. However, profound toxicity occurs when it is metabolized through oxidation in the liver, primarily by the alcohol dehydrogenase enzyme (ADH) to formaldehyde and subsequently to formic acid by aldehyde dehydrogenase (ALDH) (\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eFormic acid \u0026mdash;the metabolite of methanol and primary mediator of toxicity\u0026mdash;produces clinically significant intoxication when its plasma concentration exceeds 20 mg/dL, leading to the accumulation of formate and the development of a marked high anion gap metabolic acidosis. This metabolic disturbance is directly correlated with the buildup of toxic organic acids in the circulation (\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e, \u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e). The resulting acidemia facilitates the cellular penetration of formate, further depressing the central nervous system and causing a rapid downward spiral of tissue hypoxia (\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e). Additionally, methanol can cause retinal lesions with optic disc hyperemia, edema, and ultimately permanent blindness, as well as ischemic or hemorrhagic lesions in the basal ganglia. These changes are likely to be the result of mitochondrial oxidative phosphorylation inhibition, ultimately resulting in metabolic, cardiovascular, and neurological impairment. Multiorgan involvement, particularly renal and respiratory failure, is highly correlated with mortality (\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIntoxications in Colombia are often a consequence of fraudulent use of methanol in illicit alcoholic beverages as a substitute for ethanol or owing to deficiencies in the distillation process, principally among individuals with alcohol use disorder, who may consume methanol-containing products as a substitute for ethanol due to financial constraints or limited access to alcoholic beverages. Another route of exposure is inhalation, leading to accidental poisonings (\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e). Methanol intoxication (MI) is a relatively rare problem in our country, although it may be underreported. Reported mortality rates have reached up to 44%, with high morbidity and disabilities among survivors (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eAs a consequence of the sudden increase in the incidence of MI related to adulterated liquor consumption observed during the New Year's holiday season of 2022, it became necessary to describe the factors related to mortality in the affected patients, which could help identify potential disease-progression determinants and establish early prognosis indicators to guide the implementation of timely interventions, thereby reducing complications, sequelae, and death. The objective of this study was to describe a series of cases of patients treated for MI in Bogota, Colombia, and to contextualize the findings within the existing literature.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eA retrospective case series study was conducted on patients aged 18 years or older diagnosed with acute MI, who were admitted to the Central Eastern Healthcare Subnetwork of Bogot\u0026aacute;, Colombia, between December 2022 and February 2023. This subnetwork comprises five hospitals and sixteen primary healthcare centers serving an urban population. Diagnosis was confirmed by measurement of serum methanol concentrations through spectrophotometric analysis. Patients under 18 years of age and pregnant women were excluded.\u003c/p\u003e \u003cp\u003eAn Excel (Microsoft \u0026reg;) spreadsheet was used to collect patients' sociodemographic and clinical data from electronic medical records. Descriptive statistical analysis was performed using Stata version 15.0 (StataCorp, LLC). For quantitative variables, means, percentiles, standard deviation (SD), and variance were calculated, while categorical variables were described using frequency tables.\u003c/p\u003e \u003cp\u003e The study protocol for retrospective data collection was reviewed and approved by the research ethics committee of the Central Eastern Healthcare Subnetwork.\u003c/p\u003e"},{"header":"Results","content":"\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e summarizes the clinical and sociodemographic characteristics of the hospitalized patients with acute MI. There were 15 laboratory-confirmed cases identified. The male-to-female ratio was 4:1, with an average age of 54.5\u0026thinsp;\u0026plusmn;\u0026thinsp;10.3 years. Accidental alcohol consumption accounted for 85% of cases, while concomitant ethanol ingestion was present in 14.2% of cases. Prior consumption of other alcoholic beverages was documented in 85.7% of the cases.\u003c/p\u003e \u003cp\u003eAt admission, mean systolic blood pressure was 123.3\u0026thinsp;\u0026plusmn;\u0026thinsp;46.6 mmHg, mean diastolic blood pressure was 77.5 mmHg\u0026thinsp;\u0026plusmn;\u0026thinsp;29 mmHg, and mean arterial pressure (MAP) was 92.5 mmHg. The mean heart rate was 82.7\u0026thinsp;\u0026plusmn;\u0026thinsp;28 bpm, and the mean respiratory rate was 16\u0026thinsp;\u0026plusmn;\u0026thinsp;6.5 rpm. No febrile episodes were observed (mean temperature 36.1\u0026thinsp;\u0026plusmn;\u0026thinsp;0.4\u0026deg;C), but there was a decrease in urine output, with a mean of 0.57 mL/kg/h. One patient presented with atrial fibrillation.\u003c/p\u003e \u003cp\u003eAltered levels of consciousness were common, with somnolence in 7.1% of cases, unconsciousness in 21.4%, and coma in 35.7%. The most frequent gastrointestinal symptoms were epigastric pain, accompanied by nausea and vomiting (60%). Ocular symptoms included amaurosis (44.4%) and decreased visual acuity (22.2%), with mydriasis being the most frequent ocular sign (64.2%). Other recorded neurological manifestations were syncope (33.3%), intense headache and dizziness in five patients, and seizures in 33.3% of the cases.\u003c/p\u003e \u003cp\u003eLaboratory evaluation revealed hyperglycemia (mean glucose 175.5 mg/dL +/- 80.7 mg/dL), hyperkalemia (5.7\u0026thinsp;\u0026plusmn;\u0026thinsp;6.4 mmol/L), whereas sodium levels remained in the normal range (142.5\u0026thinsp;\u0026plusmn;\u0026thinsp;6.4 mmol/L). Metabolic acidosis was observed on arterial blood gas analysis (pH: 6.98\u0026thinsp;\u0026plusmn;\u0026thinsp;0.2; HCO3: 3.2\u0026thinsp;\u0026plusmn;\u0026thinsp;5.87 mmol/L; pCO2: 27.1\u0026thinsp;\u0026plusmn;\u0026thinsp;15.5 mm Hg; BE -18.5\u0026thinsp;\u0026plusmn;\u0026thinsp;13.5). Hyperlactatemia was also frequent, with a mean lactate level of (9.24 mmol/L\u0026thinsp;\u0026plusmn;\u0026thinsp;6.1 mmol/L.\u003c/p\u003e \u003cp\u003eMean osmolarity was 280.6\u0026thinsp;\u0026plusmn;\u0026thinsp;73.6 mOsm/kg, and a markedly elevated anion gap was observed (47.8\u0026thinsp;\u0026plusmn;\u0026thinsp;32.5 mmol/L). Evidence of renal impairment was common, with most patients presenting KDIGO stage 2 acute kidney injury (AKI) (mean creatinine 2.19 mg\u0026thinsp;\u0026plusmn;\u0026thinsp;1.2 mg/dL, BUN 16.4 mg/dL).\u003c/p\u003e \u003cp\u003eComplications observed in this case series were severe, with 13 patients (86.6%) requiring transfer to the intensive care unit, of whom 11 (78.5%) necessitated MV. Antidotal therapy consisted of ethanol administration, using aguardiente (a locally available distilled alcoholic beverage) as the ethanol source, since fomepizole was not available in the study setting. Ten patients required RRT (66.7%), and the in-hospital mortality rate was 60% (9 of 15 patients).\u003c/p\u003e"},{"header":"Discussion","content":"\u003cp\u003eThis study describes a series of 15 cases of MI in Colombia. To our knowledge, this represents the first report of this magnitude in the Latin American context, and occurred within a considerably shorter two-month timeframe compared to previous reports worldwide. This is associated with an outbreak of adulterated alcohol consumption during the 2022 holiday season.\u003c/p\u003e \u003cp\u003eAlthough MI has been widely described, the majority of the reports either correspond to large mass poisoning events or multicenter cohorts for longer periods of time. For example, the study conducted by Galvez et al. in Saudi Arabia included 50 patients over three years, only reporting surviving patients (\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e). Moreover, Zakharov described 121 patients involved in a mass MI event in the Czech Republic in 2012 (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e), and in 2020, toxicology centers in the United States reported 603 cases of methanol exposure between 2003 and 2014 (\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e). In this Colombian report, in which a considerable number of cases were recorded rapidly, the public health impact when adulterated alcohol enters the distribution chain could be observed.\u003c/p\u003e \u003cp\u003eThe in-hospital mortality rate in this study was high (60%) compared with 21% reported by Zakharov's cohort (\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e). This difference may be attributed to several factors. First, patients in our cohort often presented with severe high-anion gap metabolic acidosis, and severe acidemia is a well-established predictor of mortality in MI since it reflects the accumulation of formate and profound mitochondrial dysfunction (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). Second, the absence of fomepizole in our setting required the use of ethanol therapy, which could have introduced variability in antidotal administration and monitoring. Additionally, delayed consultation of emergency services and the socioeconomic vulnerability of the affected population may have further contributed to the severity of clinical presentation. In contrast, a portion of the patients recruited in the Czech Republic study were prospectively enrolled, allowing for early treatment measures such as fomepizole, ethanol, and hemodialysis; this could have impacted the mortality rate observed in that study.\u003c/p\u003e \u003cp\u003eConsistent with previous studies, high rates of organ failure were observed, requiring advanced organ support. Most patients required admission to the ICU, MV, and RRT. Similar findings were reported by Thongprayoon et al., who analyzed a national database of hospitalized patients with MI in the United States between 2003 and 2014, and described AKI in 22.4% of cases, along with an association between AKI and increased risk of multiorgan failure and in-hospital mortality (\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e). This pattern may be related to AKI being a causal factor in severe metabolic acidemia, therefore impacting patient outcomes.\u003c/p\u003e \u003cp\u003eThe Sequential Organ Failure Assessment (SOFA) score has been proposed as a useful prognostic tool in MI (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). Unfortunately, our study lacked this data, since not all patients underwent the needed laboratory tests to calculate the score. In relation to this, Sharif et al. studied 37 patients with accidental MI in Saudi Arabia and found that the SOFA score had an area under the curve of 0.95% for predicting unfavorable outcomes (\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e). Therefore, the SOFA score could be used to evaluate patients at risk of deterioration, determine ICU admission, and initiate early supportive therapies. However, the SOFA score has the drawback of being composed of variables that may not be altered upon initial assessment.\u003c/p\u003e \u003cp\u003eAnother factor related to poor outcomes is a prolonged latency period between methanol exposure and initiation of treatment, as suggested by Yayci et al. in a study of fatal MI cases in Turkey (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). In our case, we were unable to determine the time interval between ingestion and treatment due to unreliable data obtained from patient interviews and the lack of family members present during emergency evaluation.\u003c/p\u003e \u003cp\u003eThe population most frequently affected by MI in our study was middle-aged men, contrasting with Yaycy\u0026rsquo;s report, which indicated a younger age range between 36 and 40 years. However, that report classified ages into quintiles (\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e). In both studies, the majority of patients were chronic alcoholics who resorted to consuming methanol due to its lower cost. In our study, accidental oral consumption accounted for 85% of cases, which is in line with other series, with a lower percentage involving suicidal intent (\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn our cohort, laboratory findings demonstrated severe metabolic acidosis, with an elevated anion gap and hyperlactatemia. However, when comparing these results with previously published series, such as that of Noor et al., in which fatal cases presented even more extreme levels of acidemia, anion gap, and lactate, it is noteworthy that mortality in our study remained high despite apparently less severe metabolic disturbances (\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e). This finding suggests that the magnitude of acidemia and tissue hypoperfusion, at least as measured by these variables, may not by itself fully explain the high mortality observed. Nevertheless, this interpretation should be made with caution, as the lack of information on risk scores, therapeutic interventions received, and the availability of fomepizole at the participating centers limits the ability to make valid comparisons and draw definitive conclusions.\u003c/p\u003e \u003cp\u003eStrengths of this study include providing information to identify patients at increased risk, which may prevent complications and theoretically reduce mortality by allowing for early interventions. Most studies on MI are observational and consist of case reports and case series. Other published studies utilize national databases and retrospective analysis of accidental or self-inflicted MI reports. These studies focus on the involvement of a single organ, so this case series contributes to the understanding of local epidemiology and raises awareness among medical teams and government entities about the importance of providing adequate therapy availability and working to prevent the production of adulterated liquor.\u003c/p\u003e \u003cp\u003eLimitations of the study include its retrospective nature, the lack of SOFA scores at admission, the inability to determine the time from ingestion to treatment, the socioeconomic vulnerability of the population, which could potentially alter the expected mortality rate, the inability to determine the treatment received by all patients, and the inability to conduct follow-ups on surviving patients to evaluate their medium- and long-term sequelae.\u003c/p\u003e"},{"header":"Conclusions","content":"\u003cp\u003eMI in this series was characterized by high mortality and a frequent necessity of MV and RRT. The patients experienced intoxication in a short period of time; this temporal clustering of the cases suggests an outbreak linked to adulterated liquor and its fraudulent distribution. These findings accentuate the severe clinical impact of methanol intoxication and underscore the importance of early diagnosis in the emergency department and timely access to adequate therapy to improve patients\u0026rsquo; outcomes. In addition, they support the need for preventive strategies to reduce the risk of future outbreaks.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cp\u003eADH:Alcohol Dehydrogenase enzyme, VM: Mechanical Ventilation, ICU Intensive Care Unit, mg/dL milligrams per deciliter, mmHg millimeters of mercury, MAP Mean Arterial Pressure, BPM Beats per Minute, respirations per minute, mmol/L millimoles per liter, °C degrees Celsius, SD= Standard deviation, BUN= Blood nitrogen urea, RRT= Renal replacement therapy, MI= Methanol intoxication.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study was conducted in accordance with the ethical principles outlined in the WMA Declaration of Helsinki. The study protocol was reviewed and approved by the Research Ethics Committee of the Central Eastern Healthcare Subnetwork, Bogotá, Colombia. Given the retrospective design and use of anonymized data, the requirement for informed consent was waived by the committee.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe datasets used and analyzed during the current study are not publicly available due to institutional and patient privacy restrictions, but are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe authors received no specific funding for this work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors Contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eJG: Original idea, study design, data analysis, manuscript writing.\u003c/p\u003e\n\u003cp\u003eCC: Statistical analysis and interpretation of data, literature review.\u003c/p\u003e\n\u003cp\u003eOC: Data source search, database parameterization, patient recruitment, and project writing for the healthcare center.\u003c/p\u003e\n\u003cp\u003eAM: Literature review, introduction and discussion writing, project writing for the ethics committee.\u003c/p\u003e\n\u003cp\u003eDC: \u0026nbsp;Overall responsibility, editing, supervision, discussion, and conclusion writing, and approval of the final version.\u003c/p\u003e\n\u003cp\u003eGO: Overall responsibility, editing, supervision, discussion, and conclusion writing, and approval of the final version.\u003c/p\u003e\n\u003cp\u003eMG: Overall responsibility, editing, supervision, discussion, and conclusion writing, and approval of the final version.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgments:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe would like to thank the Central-Eastern Integrated Healthcare Subnetwork of Bogotá for providing the data and enabling the development of this research.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eLitovitz T. The alcohols: ethanol, methanol, isopropanol, ethylene glycol. Pediatr Clin North Am. 1986 Apr;33(2):311\u0026ndash;23. doi:10.1016/s0031-3955(16)35004-0 PubMed PMID: 2870460.\u003c/li\u003e\n\u003cli\u003eDudka J, Burdan F, Madej B, Szumilo J, Tokarska E, Korobowicz A, et al. Effect of selected alcohol dehydrogenase inhibitors on the human heart lactate dehydrogenase activity--an in vitro study. Acta Physiol Hung. 2004;91(3\u0026ndash;4):235\u0026ndash;41. doi:10.1556/APhysiol.91.2004.3-4.7 PubMed PMID: 16438117.\u003c/li\u003e\n\u003cli\u003eKarayel F, Turan AA, Sav A, Pakis I, Akyildiz EU, Ersoy G. Methanol intoxication: pathological changes of central nervous system (17 cases). Am J Forensic Med Pathol. 2010 Mar;31(1):34\u0026ndash;6. doi:10.1097/PAF.0b013e3181c160d9 PubMed PMID: 20010293.\u003c/li\u003e\n\u003cli\u003eAabakken L, Enger E, Jacobsen D, Str\u0026oslash;mme JH. [Metabolic acidosis--a diagnostic challenge]. Tidsskr Nor Laegeforen. 1994 Jan 30;114(3):331\u0026ndash;4. PubMed PMID: 8191432.\u003c/li\u003e\n\u003cli\u003eZuba D, Piekoszewski W, Pach J, Winnik L, Parczewski A. Concentration of ethanol and other volatile compounds in the blood of acutely poisoned alcoholics. Alcohol. 2002 Jan;26(1):17\u0026ndash;22. doi:10.1016/s0741-8329(01)00186-0 PubMed PMID: 11958942.\u003c/li\u003e\n\u003cli\u003eZuba D, Piekoszewski W, Pach J, Winnik L, Parczewski A. Concentration of ethanol and other volatile compounds in the blood of acutely poisoned alcoholics. Alcohol. 2002 Jan;26(1):17\u0026ndash;22. doi:10.1016/s0741-8329(01)00186-0 PubMed PMID: 11958942.\u003c/li\u003e\n\u003cli\u003eNemegu\u0026eacute;n Arias CE, Romero C, La Rota G. Intoxicaci\u0026oacute;n por metanol. Acta Neurol Colomb. 2025 Jun 24;41(2). doi:10.22379/anc.v41i2.1878\u003c/li\u003e\n\u003cli\u003eFiguerola B, Mendoza A, Roca M, Lacorzana J. Severe visual loss by inhalation of methanol. Rom J Ophthalmol. 2021;65(2):176\u0026ndash;9. doi:10.22336/rjo.2021.34 PubMed PMID: 34179584; PubMed Central PMCID: PMC8207856.\u003c/li\u003e\n\u003cli\u003eMd Noor J, Hawari R, Mokhtar MF, Yussof SJ, Chew N, Norzan NA, et al. Methanol outbreak: a Malaysian tertiary hospital experience. Int J Emerg Med. 2020 Feb 7;13(1):6. doi:10.1186/s12245-020-0264-5 PubMed PMID: 32028888; PubMed Central PMCID: PMC7006424.\u003c/li\u003e\n\u003cli\u003eGalvez-Ruiz A, Elkhamary SM, Asghar N, Bosley TM. Visual and neurologic sequelae of methanol poisoning in Saudi Arabia. Saudi Med J. 2015 May;36(5):568\u0026ndash;74. doi:10.15537/smj.2015.5.11142 PubMed PMID: 25935177; PubMed Central PMCID: PMC4436753.\u003c/li\u003e\n\u003cli\u003eZakharov S, Pelclova D, Urban P, Navratil T, Diblik P, Kuthan P, et al. Czech mass methanol outbreak 2012: epidemiology, challenges and clinical features. Clin Toxicol (Phila). 2014 Dec;52(10):1013\u0026ndash;24. doi:10.3109/15563650.2014.974106 PubMed PMID: 25345388.\u003c/li\u003e\n\u003cli\u003eKaewput W, Thongprayoon C, Petnak T, Chewcharat A, Boonpheng B, Bathini T, et al. Inpatient Burden and Mortality of Methanol Intoxication in the United States. Am J Med Sci. 2021 Jan;361(1):69\u0026ndash;74. doi:10.1016/j.amjms.2020.08.014 PubMed PMID: 32958166.\u003c/li\u003e\n\u003cli\u003eThongprayoon C, Petnak T, Kaewput W, Mao MA, Boonpheng B, Bathini T, et al. Acute kidney injury in hospitalized patients with methanol intoxication: National Inpatient Sample 2003-2014. Hosp Pract (1995). 2021 Aug;49(3):203\u0026ndash;8. doi:10.1080/21548331.2021.1882239 PubMed PMID: 33496631.\u003c/li\u003e\n\u003cli\u003eSharif AF, AlAmeer MR, AlSubaie DS, Alarfaj NH, AlDawsari MK, AlAslai KM, et al. Predictors of poor outcomes among patients of acute methanol intoxication with particular reference to Sequential Organ Failure Assessment (SOFA) score. Environ Sci Pollut Res Int. 2021 Nov;28(43):60511\u0026ndash;25. doi:10.1007/s11356-021-14998-w PubMed PMID: 34156622.\u003c/li\u003e\n\u003cli\u003eYayci N, Ağritmiş H, Turla A, Ko\u0026ccedil; S. Fatalities due to methyl alcohol intoxication in Turkey: an 8-year study. Forensic Sci Int. 2003 Jan 9;131(1):36\u0026ndash;41. doi:10.1016/s0379-0738(02)00376-6 PubMed PMID: 12505469.\u003c/li\u003e\n\u003cli\u003eChien WC, Chung CH, Lin CH, Lai CH. A nationwide evidence-based study of factors associated with hospitalisations due to unintentional poisoning and poisoning mortality in Taiwan. Int J Inj Contr Saf Promot. 2013;20(3):295\u0026ndash;301. doi:10.1080/17457300.2012.724689 PubMed PMID: 23003103.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Table","content":"\u003cp\u003eTable 1. Sociodemographic, clinical, and laboratory characteristics of patients in the cohort.\u003c/p\u003e\n\u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"532\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eSociodemographic Characteristics\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003en=15\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 100%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eAge (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e54.5 (10.3)\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eMale (%)\u003c/p\u003e\n \u003cp\u003eFemale (%)\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eExposure Mechanism\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e12 (80)\u003c/p\u003e\n \u003cp\u003e3 (20)\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eAccidental (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e12 (80)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eCommercial beverages (Ethanol) (%)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e2 (13.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eAny combination (%)\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e12 (85.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 100%;\"\u003e\n \u003cp\u003eClinical Presentation\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eSystolic blood pressure mm Hg (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e123.4 (46.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eDiastolic blood pressure mm Hg (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e77.5 (29)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eMean arterial pressure mm Hg (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e92.5 (34.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eHeart rate bpm (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e82.7 (28)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eRespiratory rate rpm (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e16.0 (6.55)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eTemperature (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e36.1 (0.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eUrine output (SD)\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e0.57 (0.66)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eArrhythmias\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eVentricular fibrillation (%)\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e1 (6.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eLevel of Consciousness\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eDrowsiness (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e1 (6.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eUnconscious (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e3 (20)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eComa (%)\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e5 (33.3)\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eGastrointestinal manifestations\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003eEpigastric pain, nausea, and emesis (%)\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003cp\u003e9 (60)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eOcular manifestations\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eAmaurosis (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e4 (26.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eDecreased visual acuity (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e2 (13.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eMyosis (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e1 (6.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eMydriasis (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e9 (60)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eAnisocoria (%)\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e1 (6.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eNeurological Manifestations\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eSevere headache (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e3 (20)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eVertigo (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e3 (20)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eSyncope (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e4 (26.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eSeizures (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e4 (26.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eAtaxia (%)\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e2 (13.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eLaboratory findings\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eGlycemia mg/dl (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e174.4 (80.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 100%;\"\u003e\n \u003cp\u003eNa mmol/L (SD) \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; 142.5 (6.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eK mmol/L (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e5.7 (1.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eCl mmol/L (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e101.6 (4.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003epH (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e6.98 (0.20)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003ePaO2 mm Hg (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e154.6 (99.8)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003epCO2 mm Hg (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e27.16 (15.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eHCO3 mEq (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e3.2 (5.87)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eLactate mmol/L (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e9.24 (6.1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eOsmolarity mmol/L (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e280.6 (73.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eAnion GAP mmol/L (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e47.8 (32.5)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eBUN mg/dL (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e16.4 (8.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eCreatinine mg/dL (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e2.19 (1.2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eBase excess (SD)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e-18.5 (13.5)\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eHospitalization course and outcomes\u003c/p\u003e\n \u003cp\u003e\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eICU admission (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e13 (86.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"2\" valign=\"top\" style=\"width: 100%;\"\u003e\n \u003cp\u003eNeed for mechanical ventilation (%) \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; \u0026nbsp; 11 (73.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eRRT requirement (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e10 (66.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 75.3759%;\"\u003e\n \u003cp\u003eMortality (%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 24.6241%;\"\u003e\n \u003cp\u003e9 (60)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003e\u003cstrong\u003eTable legends\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTable 1. Sociodemographic and clinical characteristics of patients with methanol intoxication (n = 15). SD = Standard deviation, bpm = beats per minute, rpm = respirations per minute, BUN = Blood nitrogen urea, ICU = Intensive care unit, RRT = Renal replacement therapy.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"international-journal-of-emergency-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ijem","sideBox":"Learn more about [International Journal of Emergency Medicine](https://intjem.biomedcentral.com/)","snPcode":"12245","submissionUrl":"https://submission.nature.com/new-submission/12245/3","title":"International Journal of Emergency Medicine","twitterHandle":"@IntJEmergMed","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Intoxication, mortality, methanol, Intensive Care Unit","lastPublishedDoi":"10.21203/rs.3.rs-9182533/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-9182533/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e \u003cp\u003eMethanol is a widely used chemical in industrial processes, and it is frequently implicated in cases of toxic alcohol exposure, especially through the consumption of adulterated or illicit liquors. Following voluntary or accidental ingestion, methanol is metabolized to formic acid, which causes severe high-anion-gap metabolic acidosis and cellular hypoxia. Serum methanol concentrations\u0026thinsp;\u0026ge;\u0026thinsp;20 mg/dL may produce a life-threatening toxicologic emergency characterized by severe metabolic disturbances and multiorgan dysfunction, which may lead to the need for ventilatory or renal support therapy with high mortality.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e \u003cp\u003eThis was a retrospective case series of patients with acute methanol intoxication admitted to the emergency departments of the Central Eastern Healthcare Subnetwork in Bogot\u0026aacute; between December 2022 and February 2023. Sociodemographic characteristics, clinical presentation, laboratory variables, and patient outcomes were retrieved from medical records and analyzed descriptively. Patients under 18 years of age and pregnant women were excluded.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e \u003cp\u003eFifteen patients with methanol intoxication were identified, with a male-to-female ratio of 4:1. The mean age was 54.5\u0026thinsp;\u0026plusmn;\u0026thinsp;10.3 years. Alcohol consumption was accidental in 85% of cases, and ethanol was co-ingested in 14.2% of cases. Ethanol antidotal therapy was administered to all patients. Severe high anion gap metabolic acidosis was observed with a mean anion gap of 47.8. Thirteen (86.6%) patients required transfer to the intensive care unit, eleven patients (73%) required mechanical ventilation, and ten patients (66%) underwent renal replacement therapy. Nine patients (60%) died during hospitalization, and visual impairment was observed in six patients (40%).\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e \u003cp\u003eMethanol intoxication in this series was characterized by high mortality, predominantly affecting middle-aged men, and a substantial requirement for renal and ventilatory support. Early diagnosis and prompt access to antidotal and supportive therapies should be prioritized in clinical settings to improve patient outcomes.\u003c/p\u003e","manuscriptTitle":"Methanol intoxication outbreak in Bogotá, Colombia: a retrospective case series of clinical characteristics, management, and patient outcomes","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-04-30 12:41:06","doi":"10.21203/rs.3.rs-9182533/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewersInvited","content":"","date":"2026-04-22T13:57:19+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-25T06:58:42+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-03-25T06:57:51+00:00","index":"","fulltext":""},{"type":"submitted","content":"International Journal of Emergency Medicine","date":"2026-03-21T01:33:49+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"international-journal-of-emergency-medicine","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"ijem","sideBox":"Learn more about [International Journal of Emergency Medicine](https://intjem.biomedcentral.com/)","snPcode":"12245","submissionUrl":"https://submission.nature.com/new-submission/12245/3","title":"International Journal of Emergency Medicine","twitterHandle":"@IntJEmergMed","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"BMC/SO AJ","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"8f85b1b9-3b89-44e3-9fc0-b0b9b83cd262","owner":[],"postedDate":"April 30th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[],"tags":[],"updatedAt":"2026-04-30T12:41:06+00:00","versionOfRecord":[],"versionCreatedAt":"2026-04-30 12:41:06","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-9182533","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-9182533","identity":"rs-9182533","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}