ADLM releases new emergency department toxicology testing guidance

The Association for Diagnostics & Laboratory Medicine (ADLM) has published new guidelines regarding emergency department toxicology testing. The guidance, “ADLM guidance document on laboratory testing for drugs of misuse to support the emergency department” can be found on the Association’s website.

The guidelines were developed through a collaboration with the Academy and Science and Practice Core Committee of ADLM. Key recommendations:

• “ED and laboratory staff should collaborate to ensure objective protocols and/or clear clinical rationale are in place for ordering drug testing in pediatric and adult patients, considering that drug test results infrequently affect acute patient management in the ED.
• Laboratories should educate ED and other specialty providers regarding the limitations of UDT, particularly false positives, false negatives, and the possibility that the presence of a drug may indicate past exposure but not necessarily have a current impact on patient behavior.
• Laboratories should evaluate which drug testing methods best support pediatric care.
• ED and laboratory staff should have procedures to ensure proper sample collection, preservation, and testing or referral for specific populations including infants.
• Drug test panels and protocols should be reviewed periodically and updated to reflect local drug use patterns. Drugs that are rarely used or with minimal clinical impact for the local patient population can be removed from test menus, and relevant drugs with available assays should be incorporated, particularly synthetic opioids such as fentanyl.
• Laboratories should provide UDT results to the ED within a mutually agreed-on window, generally 60 minutes, and testing should be clinically actionable for emergency treatment and/or follow-up care.
• A single urine specimen on ED arrival is generally sufficient for UDT. Repeat testing or alternative matrices are rarely necessary within the ED but can sometimes provide meaningful information to later investigations.
• Immunoassays should be reported qualitatively using terminology that reflects their inherent limitations, e.g., “presumptive positive” or “unconfirmed positive” and accompanied by interpretative comments that include assay cutoffs. Mass spectrometry-based screens should be reported qualitatively (e.g., detected, present) in a manner to distinguish them from immunoassays.
• Immunoassay performance characteristics depend on whether the assay is designed to detect a drug or drug class. The laboratory should educate ED staff on the performance of each assay and include interpretative comments to reflect performance.
• Drug screening at the POC has the potential for more rapid results, but laboratory and ED staff must recognize the regulatory and technical challenges as well as the drugs that can be detected at POC.
• Laboratories should assist the ED in defining frequent sources of false positives (cross-reacting compounds) and false negatives (poorly detected compounds) for the specific assays in use. 
• Laboratories should attempt to optimize detection of relevant compounds such as glucuronidated benzodiazepines and synthetic opioids.
• Laboratories should communicate test-specific cross-reactivities and limitations (e.g., false positives) to their ED providers.
• Laboratory, ED, medical toxicology, and poison control staff should collaborate to determine the optimal test menu for their patient population, e.g., whether to include specific assays for synthetic opioids.
• Mass spectrometry-based tests are most useful when the patient’s history is unreliable or unavailable, when the patient has a presumptive positive result for an immunoassay that has broad cross-reactivity, or when the drug in question cannot be detected by immunoassay. However, mass-spectrometry testing is not recommended, in any of these scenarios, unless the result could change patient management or inform follow-up care for the patient.
• Confirmatory tests provide less value when a rapid screening result is concordant with the patient’s history or prior test results. This is particularly true for immunoassay screens that have high rates of confirmation (e.g., benzoylecgonine).
• Due to its superior sensitivity and specificity over immunoassays, mass-spectrometry testing should be considered for specific patients including pediatrics or when results could facilitate downstream patient care such as psychiatric support.
• ED staff should recognize that immunoassays and many confirmatory testing panels might not detect designer drugs or NPSs. If testing is required, the provider should work with the laboratory to identify and send out testing to a specialized toxicology laboratory.
• The clinical laboratory should provide resources and educational material to assist the ED with interpretation of drug test results. Laboratories should consider appending generic or specific comments to results that clarify test performance.
• Experts such as laboratorians, medical toxicologists and/or poison control staff should be available for consultation and assistance with test interpretation.
• The clinical laboratory should review the drug test menu, including protocolized orders, with the ED periodically. The test menu should reflect local drug use patterns and results should guide patient management. 
• Chain of custody documentation is not required for clinical drug testing. However, the clinical laboratory should consider the feasibility of saving negative specimens for 48 to 72 hours and any pediatric specimens or specimens with 1 or more positive results for a longer period in case additional testing is required.”