The usefulness of urine fluorescence for suspected antifreeze ingestion in children

Purpose To evaluate urine fluorescence as a diagnostic tool. Procedures Using a Wood lamp, 60 physicians, assigned to group 1 or 2, independently rated 150 urine specimens from nonpoisoned children as fluorescent or nonfluorescent. Interobserver and intraobserver agreements were assessed. Physician ratings were compared with fluorometry results. The prevalence of urine fluorescence was determined by fluorometry. Main Findings Group 1 reported fluorescence in 80.7% (95% CI 73.4%-86.6%) of urine specimens; group 2 reported fluorescence in 69.3% (95% CI 61.3%-76.5%). Interrater agreement was poor (72.5%, κ = 0.25, 95% CI 0.13-0.37); intrarater agreement was good (physician group 1: 97.9%, κ = 0.93, 95% CI 0.77-1.00; physician group 2: 93.3%, κ = 0.85, 95% CI 0.69-1.00). The prevalence of urine fluorescence was 100% (95% CI 98.1%-100%). Conclusion Our data suggest that determination of urine fluorescence using a Wood lamp is a poor screening tool for suspected antifreeze ingestion in children.