Clinical utility of screening laboratory tests in pediatric psychiatric patients presenting to the emergency department for medical clearance.

STUDY OBJECTIVE: We assess whether screening laboratory tests obtained to medically clear pediatric psychiatric patients altered management or disposition. METHODS: This was a retrospective chart review of consecutive patients younger than 18 years and presenting to an academic pediatric emergency department for medical clearance of an acute psychiatric emergency potentially requiring an involuntary hold (danger to self, danger to others, grave disability) from July 2009 to December 2010. Patients were identified by discharge diagnosis codes. History and physical examination and screening laboratory tests were reviewed for changes in management or disposition. Further analysis compared length of stay according to type of laboratory test performed. To avoid missing patients presenting with or for evaluation of an involuntary hold for whom an organic cause was diagnosed, charts with psychiatric chief complaints were reviewed for the same period. RESULTS: One thousand eighty-two visits resulting in 13,725 individual laboratory tests were analyzed. Of 871 visits with laboratory tests performed, abnormal laboratory tests were associated with 7 disposition changes (0.8%) and 50 management changes (5.7%) not associated with a disposition change. Twenty-five patients with noncontributory history and physical examination results had management changes, all non-urgent. One patient with a noncontributory history and physical examination result had a disposition-changing laboratory result, a positive urine pregnancy test. Patients who had any screening test performed had a longer length of stay than patients without testing (117 minutes longer; 95% confidence interval 109.7 to 124.4 minutes). In charts reviewed according to chief complaint, no patient was found to have an organic cause of their symptoms according to only screening tests. CONCLUSION: Screening laboratory tests resulted in few management and disposition changes in patients with noncontributory history and physical examination results but were associated with increased length of stay.