The Limited Utility of Screening Laboratory Tests and Electrocardiograms in the Management of Unintentional Asymptomatic Pediatric Ingestions

Abstract

BackgroundSuspected ingestions are a common chief complaint to the emergency department although the majority of ingestions by children are insignificant. ObjectiveAssess the utility of screening laboratory tests and Electrocardiograms (ECGs) in unintentional asymptomatic pediatric poisonings. MethodsRetrospective chart review at a tertiary care children's hospital and a regional poison center of patients less than 12 years of age using ICD-9 codes from January 2005 through December 2008. Laboratory or ECG results requiring intervention and/or direct treatment, a non-RPC subspecialty consultation, and/or prolonged Emergency Department stay was considered changed management. ResultsFive hundred ninety five suspected ingestions met our criteria. The median age was 2.6 years (IQR 1.6, 3.0 years) and 56% were male. One laboratory test or ECG was obtained in 233 patients (39%). Of 24 screening ECGs, 32 complete blood counts and 34 blood gases, none were clinically significant. Fifty-two patients received screening metabolic panels, 3 were abnormal and 2 changed management (anion gap metabolic acidosis with unsuspected salicylate ingestions). None of the 127 (21%) screening acetaminophen levels changed management. Two of sixty-five (13%) screening salicylate levels changed management. Three screening urine toxicology tests on patients with altered mental status were positive without ingestion history. No patient under the age of 12 years with normal vital signs and normal mental status had positive screening tests. ConclusionsScreening laboratory tests and ECGs were of limited utility and rarely changed management despite being ordered in a significant number of patients. Screening tests are rarely indicated in unintentional overdoses in children who are asymptomatic.