Activated Charcoal and Bicarbonate for Aspirin Toxicity: a Retrospective Series.

Abstract

Aspirin overdose causes acid-base disturbances and organ dysfunction. Management is guided by research reported over 50years ago when chronic aspirin toxicity was common and accounted for significant morbidity. We investigate our experience of aspirin overdose and the effectiveness of charcoal and bicarbonate administration over 20years. This is a retrospective series of acute aspirin overdosefrom two toxicology units from January 2000 to September 2019. Acute aspirin ingestions > 3000mg were identified in each unit's database. Excluded were cases of chronic exposure, hospital presentation > 24 hours after ingestion, and cases without a salicylate concentration. Included in our analysis wasdemographic data, clinical effects, investigations, complications, and treatment. There were 132 presentations in 108 patients (79 females (73%)). The median age was 28years (range: 13-93years). The median dose ingested was 7750mg (IQR: 6000-14,400mg). There were 44 aspirin-only ingestions. Mild toxicity (nausea, vomiting, tinnitus or hyperventilation) occurred in 22 with a median dose of 160mg/kg. Moderate toxicity (acid-base disturbance, confusion) occurred in 16 with a median ingested dose of 297mg/kg. There were no cases of severe toxicity (coma or seizures) due to aspirin alone. The median peak salicylate concentration was 276mg/L (IQR: 175-400mg/L, range: 14-814mg/L). There was a moderate association between dose ingested and peak concentration (Pearson r = 0.58; 95% CI 0.45-0.68). Activated charcoal was administered in 36 (27%) cases, which decreased the median peak salicylate concentration (34.2 to 24.8mg/L/g (difference: 9.4, 95% CI: 1.0-13.1)). Bicarbonate was administered in 34 (26%) presentations, decreasing the median apparent elimination half-life from 13.4 to 9.3h (difference: 4.2h, 95% CI: 1.0-6.5h). Acute aspirin overdose caused only mild to moderate effects in this series. Early administration of activated charcoal decreased absorption and use ofbicarbonate enhancedelimination.