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The toxicology laboratory can fill an important role in improving patient care. Whether the service provided by the laboratory is specifically in support of a pediatric population or devoted more to the entire hospital population, the considerations involved in its configuration are the same. These considerations involve establishment of an open dialogue between the laboratory and clinical staff, an integrated and comprehensive analytic approach, and provision of reliable laboratory data in a timely fashion.

The utility of the toxicology laboratory in emergency medicine is directly related to both establishing communication between the toxicology laboratory and the clinical staff, and to providing reliable toxicology data while the diagnostic process is still in progress. When 604 patients, on whom a "complete toxicology screen" was requested, were evaluated using quantitative probes involving chemical spot tests, immunoassay, TLC and/or selected GC/HPLC methods, the resulting data were demonstrated to be of value. The ability of the clinician to accurately predict which, if any, of a large number of intoxicants were present in a given patient, was found to be minimal and as a result these combined tests were found to be essential in facilitating a proper diagnosis. Additionally, it was found that using only chemical spot tests, immunoassay and TLC in a combined qualitative approach detected 94-98% of all the substances eventually found within the population when it was further studied using more sophisticated instrumental methods. The integrated approach involving the initial establishment of a dialogue between the clinician and the toxicologist, use of simple qualitative analytical probes, confirmation of positive findings and prompt reporting of toxicology data is a viable way in which meaningful toxicology support can be provided while the diagnostic process is still under way.

The toxicology laboratory can provide diagnostic and prognostic information relevant to an alleged acute poisoning. To do this effectively, the clinician must cooperate by providing suitable specimens to and dialogue with the laboratory. The many simple laboratory tests that enable prompt qualitative results relevant to diagnosis as well as those more elegant procedures required for prognosis are briefly described. The toxicologist, by promptly reporting the results of these tests to the clinician and assisting in their interpretation, helps insure optimal patient care.

An enzyme multiplied immunoassay technique (EMIT) was used to test for opiates (morphine, hydromorphone, and codeine) in extracts of blood, bile, and tissue homogenates. All immunoassay opiate positive specimens were then tested by a reversed-phase liquid chromatographic procedure using electrochemical detection (LCEC). Blood specimens were then quantitated by LCEC. The sensitivity of the immunoassay (as morphine) was 0.020 mg/L, 0.200 mg/L, and 0.100 mg/kg for blood, bile, and tissue homogenates, respectively, with 2% intrarun and 7% interrun precision. The LCEC method was linear from 0.005 to 0.300 mg/L for morphine, hydromorphone, and codeine (nalorphine internal standard) with detection limits of 0.005 mg/L for each analyte. Intrarun and interrun precision varied from 1 to 2% and 6 to 11%, respectively. Recoveries, using a double extraction technique, ranged from 70 to 95%. These two methods, applied to 495 post mortem cases, demonstrated a 6% incidence of opiates, with no false positives.