Laboratory Error Masquerading as Toxic Alcohol Ingestion: A Teaching Case Report

Introduction: Elevated osmolar gap is strongly associated with toxic alcohol ingestion, often triggering reflexive interventions including emergent hemodialysis. Clinical-laboratory discordance should prompt critical re-evaluation before invasive procedures.Case Presentation: A 51-year-old woman presented with altered mental status and an osmolar gap of 427 mOsm/kg with high anion gap metabolic acidosis, initially suggesting toxic alcohol ingestion. Critical evaluation revealed that the primary disturbance was respiratory acidosis, the patient responded to naloxone, and the implied alcohol concentrations would be incompatible with survival. A repeat osmolality was 314 mOsm/kg, uncovering a transcription error: the laboratory technician had entered the specimen collection time (7:08 AM) as '708' instead of the true osmolality (310 mOsm/kg). The patient recovered with supportive management for opioid overdose and acute kidney injury, without hemodialysis.Conclusion: Clinicians must critically reassess when laboratory results are discordant with the clinical picture. A brief pause before irreversible interventions upholds patient safety and resource stewardship.