C. Andrew Robinson

New automated chemiluminescent assay for erythropoietin.

Erythropoietin (EPO) is a polypeptide hormone produced by the kidney that regulates erythropoiesis by controlling the proliferation and differentiation of erythroid progenitors in bone marrow. Assays for EPO are used to monitor dosage and response to human recombinant erythropoietin also may have diagnostic utility in the differential diagnosis of anemia and polycythemia. We evaluated an automated, chemiluminescent immunoassay for EPO (DPC Immulite) in terms of precision, linearity, interference, and correlation with reference assays. The Immulite assay demonstrated acceptable correlation with the reference immunochemiluminometric method (slope = 1.087, y intercept = 0.567, R value = 0.990). Within‐run CVs ranged from 2.3% to 5.0%, while between‐run CVs ranged from 4.1% to 9.5%. Linearity extended beyond the manufacturer’s stated claims, and recovery ranged from 96.8% to 100.9% across the concentrations tested. No significant interference was noted with hemoglobin, bilirubin, or triglyceride. Overall, this method compares favorably with the existing immunochemiluminometric reference method and offers clinical laboratories an alternative for the analysis of erythropoietin. J. Clin. Lab. Anal. 14:271–233, 2000.

Utilization, Reliability, and Clinical Impact of Point-of-Care Testing during Critical Care Transport: Six Years of Experience

The use of point-of-care testing (POCT) has been reported in the setting of critical care transport (1)(2)(3)(4)(5)(6), although the overall benefits have not been evaluated in depth. In addition, problems with testing reliability may be uncovered only after an extended period of field use. This report describes the use of POCT by our critical care transport program over 6 years. All critical care transports made from January 1996 to December 2001 were reviewed. Transport vehicles were ambulances or twin-engine jets. The transport teams consisted of a physician on transport or with radio contact, a respiratory therapist, and a registered nurse. All transports were equipped with i-STAT® portable analyzers (i-STAT® Corporation) and disposable cartridges for testing. The analyzer and cartridges were stored in an insulated bag for temperature control during the trip. The analytical performance verification protocol (electronic controls) recommended in the i-STAT System Manual was followed before each patient test. Liquid controls were run monthly. Proficiency testing was completed in accordance with the requirements of the College of American Pathologists. The manufacturer’s test cartridges were the G3, 6+, EG7+, and glucose. Tests included pH, P co2, P o2, calculated bicarbonate, total CO2, base excess, oxygen saturation, sodium, potassium, chloride, urea, glucose, hematocrit, and calculated hemoglobin and glucose. Each cartridge requires 65 μL of whole blood for testing. The blood was drawn and analyzed by physician order. From 1997 through 2001, the team filled out an evaluation form for quality review after cases where POCT was performed. Patient test results and charts for each POCT episode were reviewed retrospectively to identify changes in treatment linked to test results. Other data were extracted from transport department and quality-control records. This research was approved by …

Detection of azide in forensic samples by capillary electrophoresis.

Azide salts are highly toxic compounds that have been difficult to detect in forensic samples. Here, anion analysis by capillary electrophoresis with indirect spectrophotometric detection was applied to detect azide in forensic specimens from two suicide victims. Gastric specimens from the victims were shown to have high azide concentrations; azide represented one of the major anionic components and no corresponding component occurred in normal gastric juice. Samples of blood and bile had low concentrations of azide near the limits of detection. The method described for azide analysis used simple steps for sample preparation and analysis time was less than 10 min per sample. It offers a simple and reliable method for detecting azide in biological fluids.

Unexplained Sudden Death and the Likelihood of Drug Abuse

The common history of drug abuse in adults with an undetermined cause of death has led us to hypothesize that chronic drug abuse increases the risk of sudden death. To begin evaluating this hypothesis, we conducted a retrospective case-control study of 61 decedents whose cause of death remained undetermined following autopsy matched one to one to a control group of pedestrians or passengers killed in motor vehicle collisions. In 21 pairs, the case subject had evidence of drug abuse but the control did not, and in 5 cases the reverse was true. Analysis showed that individuals with an undetermined cause of death are 4.2 times more likely to have evidence of drug abuse than are victims of a motor vehicle collision.

Detection of Ketosis in Vitreous at Autopsy after Embalming

Ketosis occurs in ketoacidosis or malnourishment. When either is suspected in relation to a death, it may be important to analyze for ketosis at autopsy. We encountered a case where starvation was suspected in a deceased nursing home resident, where the body had been embalmed prior to autopsy. Gas chromatography (GC) was unable to separate acetone from formaldehyde, a component of embalming fluid. The Acetest is a simple test that can detect acetone and acetoacetate in body fluids. We validated the Acetest with GC on vitreous. The Acetest and GC were consistent except at very low levels of acetone or acetoacetate. The sensitivity of the Acetest for acetoacetate in vitreous was 10 mg/dL, consistent with early starvation. Significant interference from embalming fluid did not occur. The Acetest was negative in the described case. The Acetest is a simple and useful test for the detection of ketosis in embalmed autopsies.

Evaluation of the Beckman Coulter LX20 Clinical Chemistry Analyzer

Our goal was to consolidate different methodologies in the clinical chemistry laboratory and replace aging analyzers; therefore, we evaluated the newly available Beckman Coulter LX20 (Brea, CA). Results were obtained for linearity, within- and between-day precision, correlation, interference, and serum-vs-plasma studies. Satisfactory precision results were obtained, with most assays demonstrating within-day coefficients of variation less than 2% and between-day coefficients of variation less than 5%. The linearity for all assays was acceptable over the range tested. Correlation results were adequate. The major difference in serum-vs-plasma studies was potassium. The only significant interferences noted were that lipemia decreased uric acid and bilirubin results, while hemolysis increased potassium results. We conclude that the LX20 demonstrates good performance capabilities, making this instrument suitable for a medium- to high-volume laboratory.

Creation of a Queryable Toxicology Database Available to Forensic Pathologists

Purpose Forensic pathologists typically depend upon case reports or published compilations of case reports when determining the role a drug may have played in death. Case reports may provide a helpful range, but the cases reported are typically few and often lack information on circumstances surrounding death and autopsy findings. A searchable database recording circumstances, autopsy findings, drug concentrations, and the cause and manner of death would allow forensic pathologists to compare a specific case to similar cases, facilitating evaluation and interpretation of toxicology results. Method This project uses data extracted by computer programs from over 18 000 computer files of autopsy and toxicology reports generated between 2004 and 2012. Using PHP Hypertext Preprocessor and MariaDB, a relational database, we developed a webpage that stores the data and allows for complex queries. Results Users can search for cases by specifying drugs and medical conditions, demographics, height, body mass, and manner of death. The number of cases with a given drug for this eight-year span from one office is comparable to the numbers reported in compilations of case reports. Conclusion Our webpage enables a pathologist evaluating a case to search the database for cases with similar circumstances and findings. New cases are easily added to the database as they are completed. The database allows other institutions to contribute data and records the data source, which increases the usefulness of the database even more. This database provides pathologists a powerful new tool for the evaluation of toxicology findings in their practice.

Computer Extraction of Data from Autopsy and Toxicology Reports

Purpose Forensic autopsies contain a wealth of information ranging from toxicology results to organ masses. Extracting data by hand from years of reports is tedious. We report a computer program that extracts information from reports in Word, WordPerfect, or Portable Document Format (PDF). Methods The program consists of three Excel macros, written in Visual Basic for Applications, which extract information from autopsy and toxicology reports. The user selects a macro, chooses a folder of documents, and inputs key words to guide the search. The macros open each document in the folder sequentially, extract the desired values automatically, and enter the data into the respective case numbers row in a spreadsheet. Another macro combines data from the separate autopsy and toxicology reports by matching the unique case number. Extraction of PDF files is a two-step process involving batch conversion from PDF format to Word with subsequent extraction. Results We have developed a set of macros that extract data from autopsy and toxicology reports, such as age, race, height, manner and cause of death, and drug concentrations. Key words included autopsy headings, such as “Cardiovascular System” and units of measure such as “inches” or “pound.” We analyzed roughly 7000 cases and kept 3455 cases. Conclusions Our system rapidly procures data and places the information in a standardized format. This program will be hosted on our toxicology webpage for others to use. Future goals include combining data from other institutions and uploading the data to an online, queryable database.

n‐Ethyl Pentylone‐Related Deaths in Alabama

n‐Ethyl pentylone (NEP) is a chemical substance derived from cathinone. Synthetic cathinones are an evolving group of drugs with stimulating, mind‐altering effects sometimes referred to as novel or new psychoactive substances (NPS). There is scarce information in the medical literature regarding forensic cases in which NEP is detected in toxicological testing. We present four fatalities involving NEP from Alabama in 2017. Deaths were attributed to NEP toxicity in two cases (peripheral blood concentrations of 0.121 and 0.953 mg/L) and injuries caused by gunshot wounds in two cases (peripheral blood concentrations of 0.045 and 0.031 mg/L). One case involving NEP described an individual who exhibited classic CNS‐stimulant induced erratic behavior before being found dead. These cases enhance the forensic literature regarding specific NPS like NEP and provide contextual reference for professionals considering the significance of NEP in toxicological interpretation.

Quantification of Loperamide by Gas Chromatography Mass Spectrometry

Due to reported pharmacological activity similar to classical opioids at supratherapeutic concentrations, abuse of the anti-diarrheal medication loperamide (Imodium AD™) has become a target in the opioid epidemic. While this phenomenon is not new, published quantitative analytical methods use liquid chromatography tandem mass spectrometry. Described here is an 11 min method for quantification of loperamide in postmortem whole blood by gas chromatography mass spectrometry. Validation studies performed followed SWGTOX guidelines and included: accuracy, specificity, limit of detection (LOD), regression model analysis, stability, and matrix recovery enhancement and/or suppression. The accuracy study consisted of inter-day, intra-day, reproducibility and dilution integrity experiments. Inter-day and intra-day accuracy, precision and coefficient of variation (CV) were measured; normalized results were 1.05 ± 0.09 with 8.87% CV (n = 36) and 1.03 ± 0.09 with 8.53% CV (n = 27), respectively. Reproducibility was evaluated through standard addition with an observed CV of 10.84% (n = 10). Dilution integrity (2× and 4×) resulted in 0.94 ± 0.13 with a CV of 13.9% (n = 5). No interference was observed through analyses of the internal standard (loperamide-d6), endogenous compounds (10 blank matrices) or 60 commonly encountered analytes. The LOD/decision point was 100 ng/mL (CV 8.40%). A linear calibration model was established from 100 to 1,000 ng/mL. Stability was examined; observed analyte-to-internal standard response resulted in 6.59% CV. Recovery was determined for loperamide and loperamide-d6 (31% and 36%, respectively). Neither matrix suppression nor enhancement was observed with loperamide at 750 ng/mL and loperamide-d6 at 300 ng/mL (-6.5% and -4.2%); however, some suppression was exhibited at lower concentrations (-39.8%). The designed method was determined to be sufficient for the analysis of loperamide-related death cases in Alabama (n = 8) and offers postmortem toxicology laboratories an alternative approach that is both highly selective and specific.