Clinical Characteristics and Prognostic Factors in Methanol Intoxication: A Retrospective Study from a Tertiary Emergency Department

Objective: Methanol poisoning remains a major cause of toxicological mortality due to the diagnostic challenges and delayed presentation. This study aimed to evaluate the epidemiological profile, clinical features, laboratory parameters and outcomes of patients presenting to the emergency department with methanol intoxication. Methods: This retrospective study included patients admitted to our emergency department between January 1, 2017, and January 1, 2021, with a clinical diagnosis of methanol poisoning. Inclusion criteria were: suspected methanol ingestion, supportive history and physical findings, and high anion gap metabolic acidosis (pH < 7.3, HCO₃ < 20 mEq/L, anion gap > 20 mEq/L). Demographic data, presenting symptoms, laboratory values, and outcomes were compared between survivor and non-survivor groups. Results: Among 41 patients, 87.8% were male with a mean age of 52.2 ± 10.8 years. In-hospital mortality was 41.5%. Altered mental status at presentation was significantly more frequent in non-survivors (64.7%) than survivors (25.0%, p = 0.011). Mortality among patients with altered consciousness reached 69.2%. Survivors presented more often with visual complaints (54.2% vs. 23.5%), though the difference was not statistically significant(0.101). Non-survivors had lower mean pulse rates (84.5 ± 23.2 vs. 106.0 ± 26.6 bpm, p = 0.004), and more severe metabolic acidosis (mean pH 6.86 ± 0.23, HCO₃ 6.66 ± 3.57, base deficit −23.77 ± 5.23). ROC analysis confirmed strong associations between mortality and low pH, bicarbonate, and base deficit levels, as well as elevated lactate, glucose, and anion gap values. Conclusion: Methanol poisoning diagnosis is primarily clinical, and early detection is vital to reduce morbidity and mortality. The severity of metabolic acidosis and altered mental status at admission are key indicators of poor prognosis.