Methanol mass poisoning in Estonia: Outbreak in 154 patients

Abstract

Background. Knowledge of methanol toxicity is based on human data from case series and larger outbreaks. In many of these cases, however, diagnosis was not verified by methanol determinations. We present epidemiological and clinical data from one of the largest methanol outbreaks in which all patients had detectable serum methanol levels. Methods. Retrospective case series study of hospital and forensic charts from the five hospitals where patients were treated. Results. Of the 147 patients admitted with suspected methanol poisoning, the diagnosis was confirmed in 111, of whom 25 (23 %) died. In addition, 43 patients died outside the hospital, giving a total of 154 patients and a death toll of 68 (44 %). Outcome was related to the degree of metabolic acidosis, serum methanol concentration, coma upon admission, and the patient's ability to hyperventilate. Patients were treated with bicarbonate (85 %), ethanol (87 %), hemodialysis (71 %), and mechanical ventilation (61%) according to clinical features and blood gases, since serum methanol concentrations were analyzed retrospectively. Twenty patients (18 %) survived with permanent sequelae, 18 suffered from impaired vision, and 3 developed permanent brain damage. Discussion. Given limited resources, triage and use age of tertiary care centers allowed a small community hospital to treat a high number of methanol-poisoned patients. Critical resources were ventilators and dialyzing machines, whereas stores of antidote (ethanol) and bicarbonate were sufficient. Many patients were mechanically ventilated by hand and treated with bicarbonate and ethanol during transport to tertiary care centers for hemodialysis.