RESULTS OF LIMITED VERSUS COMPREHENSIVE TOXICOLOGY SCREENING IN A UNIVERSITY MEDICAL-CENTER

Both comprehensive toxicology screening (COM) and limited toxicology s creening (LIM) were performed on the same urine in 1,734 consecutive c ases over a 6-month period at a university medical center. About half of the screens originated from inpatient services and half from outpat ient services (mostly emergency department). In 71% of the cases, ther e was agreement between the results of LIM and COM, with 47% of cases being negative. For 500 screens (accounting for 655 individual discrep ant findings), at least one discrepancy was noted between LIM and COM. Of these, 399 cases demonstrated at least one finding with COM, but n ot with LIM (''false-negative'' LIM). Topical anesthetics (including c ocaine and cocaethylene), antiepileptics, and sympathomimetic amines a ccounted for 65% of findings. In contrast, 147 cases showed a finding with LIM, but not with COM (''false-positive'' LIM), mostly amphetamin es. In certain specified clinical circumstances, LIM may be a more cos t effective and efficient approach than COM.