Challenges in Diagnosing Comatose Patients with Ethylene Glycol Poisoning

A 41-year-old man with a long history of depression presenting with consciousness disturbance was brought to a hospital. Upon examination, his level of impairment was classified as E3V4M6 according to the Glasgow Coma Scale (GCS). The patient’s vital signs were stable; however, laboratory examination showed marked metabolic acidosis (pH 7.219, pCO2 18.3 mmHg, base excess -17.4 mmol/L, anion gap 36.9 mmol/L, lactate level 13.7 mmol/L). He did not have a history of drug or alcohol abuse, and he had not been prescribed specific medication that could cause lactic acidosis.