Mass spectrometry in emergency toxicology: Current state and future applications

This manuscript offers a broad overview of the state of emergency toxicology testing in clinical laboratories. We summarize the specific challenges of performing emergency toxicology testing, introduce a variety of currently used methods including mass spectrometry, and compare and contrast the utility of different types of mass spectrometers for this purpose. Finally, we examine evidence on the utility of toxicological testing in the treatment of poisoned patients, with special emphasis on the demonstrated utility of mass spectrometry-based tests. This review included primary literature indexed in the NCBI PubMed Database. Search terms included "emergency toxicology", "emergency mass spectrometry", "mass spectrometry toxicology", "utility of toxicology testing", and "toxicology surveillance". There are relatively few clinical trials on the utility of toxicology testing in overdosed or poisoned patients, and those studies that exist have a number of limitations. One of the most significant is that nearly all were conducted with immunoassay-based tests, which can only detect a limited number of compounds and are known to have a high false-positive rate. In addition, few are prospective. The overwhelming majority of studies of immunoassay-based tests concluded that results rarely changed patient management, regardless of the patient's clinical presentation. Many of these studies suggest that results could still be useful in other contexts, including identification of opportunities to refer a patient to substance abuse treatment or avoidance of drug-drug interactions. Mass spectrometry-based testing has several advantages over immunoassays, including the breadth of compounds that can be detected and substantially higher specificity, yet many questions remain about utility in emergency toxicology. The utility of mass spectrometry-based testing has not been assessed in a prospective clinical trial, rather the literature is overwhelmingly case-based, and a small number of laboratories are responsible for the majority of the case reports. The limited evidence that exists suggests that mass spectrometry can be useful in emergency situations, provided that results are available rapidly, interpreted by a knowledgeable physician, and that the scope of the method includes the compound implicated in the poisoning. Like results from immunoassays, many authors report using mass spectrometry-based testing for purposes other than direct patient care, namely surveillance of emerging drugs and trends in local drug use. A number of case reports and larger case series present evidence in support of this use. Despite the potential advantages of mass spectrometry, the quantity and quality of published evidence are not sufficient to adequately assess the utility of mass spectrometry-based emergency toxicology results. This is a field that is ripe for investigation, particularly as mass spectrometers become less expensive and the technology is adopted by an increasing number of clinical laboratories. There is a strong need for prospective studies on implementation of STAT mass spectrometry-based tests in emergency toxicology and larger scale assessments of impact on acute patient care as well as public health.