Ethanol elimination kinetics following massive ingestion in an ethanol naive child

Objective: At low-to-moderate concentrations, ethanol elimination follows zero-order kinetics. It is unknown whether renal, pulmonary or other first-order processes become significant in patients with very high serum ethanol concentrations. Additionally, it is unclear whether ethanol naive subjects induce their metabolism during acute intoxication. We present the toxicokinetic analysis in a child with a massive ingestion of ethanol. Case report: A 15-year-old girl without significant medical history presented to the Emergency Department after drinking 24 ounces of tequila. She was found unresponsive at home with a Glasgow Coma Score of 3. Her presenting vitals were as follows: 118/69 mmHg blood pressure; pulse rate was 88 beats per minute; respiratory rate of 20 breaths per minute; pulse-oximetry is 96% on room air. Other than obtundation, her physical examination was normal. She was intubated for airway protection and admitted to the ICU. Her initial serum ethanol concentration was 543 mg/dL. A repeat level 3 h later was 722 mg/dL. Post-absorptive ethanol concentrations decreased from 693 mg/dL to 291 mg/dL over the following 15.5 h. The patient had spontaneous eye opening 24 h after presentation. Her projected serum ethanol concentration at that time was 215 mg/dL. She was extubated 2 h later and had an uneventful recovery. Results: The elimination of ethanol in the post-absorptive phase remained zero-order at a rate of 26.3 mg/dL/ h (5.7 mmol/L/h) with a Pearson' correlation coefficient (R2) of 0.9968 (p < 0.01). There was no evidence of acute induction in metabolism although pharmacodynamic tolerance likely occurred. Conclusion: Even at very high ethanol concentrations in ethanol naive subjects, elimination of ethanol follows a zero-order toxicokinetic model.