(1495) Decreased Oxygen Extraction Ratio and Shock Secondary to Ibuprofen Overdose

Introduction: Massive ibuprofen ingestion can result in coma, anion gap acidosis, shock, GI bleeding, and renal failure. Experimental studies have shown non-steroidal anti-inflammatory drugs (NSAIDs) can cause mitochondrial uncoupling. Mitochondrial uncoupling can present clinically with decreased oxygen extraction. Here we present the case of a child with decreased oxygen extraction ratio due to ibuprofen overdose.

Description: A 15-year-old boy presented with obtundation and cardiovascular collapse after a presumed intentional ingestion. He required mechanical ventilation and triple vasopressor therapy for hypotension unresponsive to crystalloid resuscitation. Laboratory evaluation demonstrated worsening anion gap acidosis, elevated lactate, and decreased oxygen extraction ratio with mixed venous O2 saturation 92-97% and bilateral cerebral near-infrared spectroscopy monitoring with values of 95, concerning for impaired oxygen utilization given arterial saturation of 99-100%. Altered mental status persisted with minimal need for sedation. Given uncertainty of diagnosis, he received empiric treatment for potential cyanide poisoning and beta blocker toxicity. He received methylene blue for vasoplegia. None of these interventions led to improvement in hemodynamics or acidosis. Prognosis was thought to be poor. After deliberation, a hemodialysis line was placed and empiric continuous renal replacement therapy (CRRT) was initiated. Acidosis improved rapidly and his oxygen extraction ratio improved in 12 hours. Patient’s family ultimately found empty bottles of ibuprofen in patient's bedroom, subsequently discovered to be ~80 g (>1000mg/kg) of ibuprofen. His ibuprofen level 2 days after ingestion was 170 mcg/mL (reference range 10-50). In the following days, all labs normalized, CRRT was discontinued, and patient was extubated and found to be neurologically intact.

Discussion: Although rare, massive NSAID overdose can cause coma, anion gap acidosis, and shock. This is the first known report of decreased oxygen extraction ratio in NSAID overdose, presumably from mitochondrial uncoupling. Treatment is supportive and may include hemodialysis, which does not clear ibuprofen but does improve acidosis.