Abstract: PUB115
Severe Osmolar Gap Without Significant Anion Gap Acidosis: Isopropyl Alcohol Intoxication Mimicking Undifferentiated Shock
Session Information
Category: Fluid, Electrolytes, and Acid-Base Disorders
- 1102 Fluid, Electrolyte, and Acid-Base Disorders: Clinical
Authors
- Sadurski, Filip, Mass General Brigham, Salem Hospital, Salem, Massachusetts, United States
- Saldanha Neves Horta Lima, Carolina, Mass General Brigham, Salem Hospital, Salem, Massachusetts, United States
- Hamarsha, Zaid, Mass General Brigham, Salem Hospital, Salem, Massachusetts, United States
Introduction
Isopropyl alcohol intoxication differs from other toxic alcohol ingestions by producing a markedly elevated osmolar gap without significant anion gap metabolic acidosis, since its metabolism produces the uncharged ketone acetone. Severe presentations may mimic stroke, sepsis, or post-ictal states, delaying recognition and treatment. We present a case highlighting the diagnostic value of osmolar gap interpretation and supportive management.
Case Description
A 41-year-old man with prior hemorrhagic stroke and residual right-sided weakness presented with abrupt dizziness with bowel incontinence and acute unresponsiveness. On arrival, he was obtunded GCS 3, hypothermic 93°F, hypotensive 89/52 mmHg, and tachypneic, requiring emergent intubation and norepinephrine support. Computed tomography of the head was unremarkable.
Laboratory evaluation demonstrated pH 7.24, pCO2 51, lactate 5.2 mmol/L with gap elevation to 17, serum osmolality 369 mOsm/kg, and osmolar gap 68 mOsm/kg. Urinalysis revealed mild ketonuria. Routine toxicology screening was otherwise negative; however, volatile alcohol testing confirmed isopropyl alcohol 153 mg/dL and acetone 135 mg/dL. History revealed an empty sanitizer bottle was identified in his room. Broad-spectrum antibiotics were started for presumed septic shock but discontinued after infectious evaluation was unrevealing. The patient was managed with mechanical ventilation, intravenous crystalloids, and vasopressor support. Hemodialysis was not required. Extubation was delayed by airway edema requiring corticosteroids after bronchoscopy and failed cuff leak testing; he was successfully extubated on hospital day four. Osmolality and osmolar gap normalized, and mental status returned to baseline. Psychiatric evaluation suggested accidental ingestion after dental procedure.
Discussion
Isopropyl alcohol intoxication should be suspected in patients with a markedly elevated osmolar gap without significant anion gap metabolic acidosis. Metabolism to acetone produces ketosis without acidemia, distinguishing it from other toxic alcohol ingestions
that generate organic acid metabolites. Management is supportive, with renal replacement therapy reserved for refractory shock, severe acidosis, or deterioration. This case highlights the importance of osmolar gap interpretation in differentiating toxic alcohol ingestions to avoid unnecessary interventions.