Evaluation of Clinical and Biochemical Variables in Acute Methanol Poisoning: Is blood pH a Good Prognostic Factor for Prediction of Outcome?

Background: Acute methanol poisoning is one of the most important chemical poisoning due to drinking of illegal and handmade alcoholic beverages in Iran. The aim of this study was to evaluate clinical and biochemical parameters as prognostic factor in acute methanol poisoning. Methods: A retrospective study was performed on acute methanol poisoning cases admitted to the Loghman Hakim Hospital Poison Center (Tehran, Iran) over a two-year period. The demographic data, clinical presentations, paraclinical findings and patients’ outcome were extracted from medical records. Results: During this period, thirty patients with acute methanol poisoning have been enrolled in the study. All of the patients were men, with the median age of 25.5 years. Visual disturbances, respiratory manifestations, and loss of consciousness were the most common clinical manifestations on admission. The median of blood methanol level was 20 mg/dL. The median of pH, PaCO2 and HCO3 was 7.15, 22.35 mmHg and 7.2 mEq/L, respectively. Fatality rate was 30%. There was a significant difference between survivors and non-survivors with regards to coma, blood methanol level, and PaCO2 and blood glucose. Also, we did not observe a significant difference between these two groups regarding pH and HCO3 level. Conclusion: It can be suggested that coma, PaCO2 and hyperglycemia on admission time could be used as strong predictors of poor outcome and blood pH and HCO3 is not a good prognostic factor for assessment of methanol poisoning outcome.