Intoxication cases are often urgent, confounding, and depend heavily on laboratory results. In pediatric cases there is added complexity due to the patient’s age, and they often involve a multidisciplinary team of clinical providers, social workers, and laboratorians. The decisions from these cases are carefully considered as they may have long term repercussions to the welfare and social outcome of the patients, their families, and those providing the medical care: A false negative can place the child back in a dangerous home situation, whereas a false positive due to an interference can result in a child being removed from their family wrongfully.
The session by Drs. Kara Lynch and Stephen Roper, “Testing Strategies for Detecting Pediatric Drug Exposure: A Case Based Discussion Children Toxicology Cases,” presented novel approaches for improving toxicology testing in the pediatric population. The presenters discussed the application of technologies and workflows directed at improving the weaknesses of the traditional screen and confirmation approach for drug exposure.
Lynch began by explaining that toxicology in pediatrics is too often only talked about as in utero care, but not so much in other pediatric populations. She went on to share several cases of pediatric acute drug exposure, highlighting how different approaches to testing could yield different results and interpretations.
One of these cases highlighted the importance of updating urine drug screens, for example including testing for fentanyl due to the opioid epidemic. Lynch also described high resolution mass spectrometry (HRMS) and highlighted the role that HRMS can play in identifying the drugs to which a patient has been exposed.
Lynch went on to share that in many instances, pediatric patients are exposed to prescription medication and many times these drugs are not part of an immunoassay screen.
Lynch’s cases showed that it is not uncommon to discover unexpected drugs when the lab uses an HRMS method. Her presentation reinforced the importance of having a definitive result, because this information is not only used by the clinicians but also by child protective services to make a decision. Although mass spectrometry methods are superior to immunoassay methods in terms of sensitivity and specificity, they have not yet replaced immunoassay methods due to longer turnaround time (TAT) and increased technical complexity.
Lynch believes that improvements can still be made to current pediatric toxicology workflows, even without the availability of mass spectrometry technology—for example, including tests for additional drugs like fentanyl. In addition, having a close relationship with child protective services and local toxicology laboratories can help educate ordering providers on the intricacies of the tests. Finally, she recommended that clinical providers order drug testing early in their assessments to simplify diagnosis and avoid costly workups.
In the second talk, Roper presented his experiences in implementing a revolutionary testing model centered on direct testing with mass spectrometry. The objective was to develop a definitive, qualitative mass spectrometry method and would only require very small quantity of sample.
He explained how he was able to get buy-in at his institution to implement this model by convincing providers that the longer TAT was worth it due to having a definitive result. He noted that in practice, a negative result had a TAT of about 30 minutes, and a positive result of about 90 minutes, since they are repeated and reviewed by a medical director. One of the bigger challenges with a direct mass spectrometry method was familiarizing technologists with it. That was overcome with practice and the medical director review process.
Another benefit of the new method is that it’s used both on pediatric and maternal samples to help harmonize interpretation. A future goal is to centralize testing for all newborn and pediatric specimens in the region to one location.
Roper underscored that the new method dramatically reduced the number of false positives in the nursery population compared to immunoassay. Moreover, the improved sensitivity increased detection of illicit drug exposures, while at the same time the overall TAT for positive results dropped compared to the traditional screen and confirmation approach.