Neurologic Complications in Critically Ill Patients with Toxic Alcohol Poisoning: A Multicenter Population-Based Cohort Study.

BACKGROUND: Toxic alcohol poisoning is regularly encountered in emergency departments and intensive care units (ICUs). Most patients present with an altered level of consciousness, but the subsequent course and spectrum of neurologic complications and outcomes is highly variable.

METHODS: We performed a population-based, multicenter retrospective cohort study of critically ill patients with toxic alcohol poisoning admitted to ICUs in Alberta, Canada, between 2007 and 2019 to describe neurologic sequelae, including seizures, coma, neuroimaging abnormalities, persistent cognitive or visual impairment, and mortality. Multivariate analysis was performed to identify predictors of poor outcome.

RESULTS: We identified 104 patients, including 55 (53%) with methanol ingestion, 36 (35%) with ethylene glycol ingestion, and 13 (13%) with isopropanol ingestion. In patients who underwent neuroimaging, abnormalities were detected in 9 of 24 (38%) with methanol toxicity, 5 of 20 (25%) with ethylene glycol toxicity, and 0 of 10 with isopropanol toxicity (p = 0.07). Basal ganglia were commonly involved with both methanol and ethylene glycol poisoning, but prominent subcortical involvement and restricted diffusion were observed only with methanol poisoning. The composite of death, persistent cognitive impairment, or visual loss occurred in 13 (24%) patients with methanol poisoning, compared with one (3%) with ethylene glycol poisoning and none with isopropanol poisoning (p = 0.006). Among patients with methanol toxicity, greater elevation of the anion gap and lower Glasgow Coma Scale score were independent predictors of poor outcome. No patient with an anion gap ≥ 28 at presentation had a favorable recovery. Progression to death by neurologic criteria occurred in 3 of 55 (5%) patients with methanol poisoning and in none with other toxic alcohols.

CONCLUSIONS: Methanol overdose is the most common form of toxic alcohol poisoning to result in ICU admission. Poor neurologic outcomes may occur especially with methanol poisoning, with more than one in five patients dying or having persistent cognitive or visual impairment. A wide anion gap independently predicts poor outcome, emphasizing the importance of expeditious recognition and treatment.