Biological Testing and Interpretation of Laboratory Results Associated with Detecting Newborns with Substance Exposure.

BACKGROUND: Substance use during pregnancy is common, as is biological testing that is intended to help identify prenatal exposures. However, there is no standardized requirement for biological testing with either maternal or newborn specimens, nor is there standardization related to when testing occurs, how frequently testing occurs, what specimen(s) to test, what substances to test for, or how to perform testing. CONTENT: We review common specimen types tested to detect maternal and newborn substance exposure with a focus on urine, meconium, and umbilical cord tissue. We also review common analytical methods used to perform testing, including immunoassay, and mass spectrometry platforms. Considerations regarding the utilization of testing relative to the purpose of testing, the drug analyte(s) of interest, the specific testing employed, and the interpretation of results are emphasized to help guide decisions about clinical utilization of testing. We also highlight specific examples of unexpected results that can be used to guide interpretation and appropriate next steps. SUMMARY: There are strengths and limitations associated with all approaches to detecting substance exposure in pregnant persons as well as biological testing to evaluate a newborn with possible substance exposure. Standardization is needed to better inform decisions surrounding evaluation of substance exposures in pregnant people and newborns. If biological sampling is pursued, testing options and results must be reviewed in clinical context, acknowledging that false-positive and -negative results can and do occur.

A Holistic Framework for the Evaluation of Kidney Function in a Gender-Diverse Landscape.

The most commonly used equations to estimate glomerular filtration rate incorporate a binary male-female sex coefficient, which has important implications for the care of transgender, gender-diverse, and nonbinary (TGD) people. Whether "sex assigned at birth" or a binary "gender identity" is most appropriate for the computation of estimated glomerular filtration rate (eGFR) is unknown. Furthermore, the use of gender-affirming hormone therapy (GAHT) for the development of physical changes to align TGD people with their affirmed gender is increasingly common, and may result in changes in serum creatinine and cystatin C, the biomarkers commonly used to estimate glomerular filtration rate. The paucity of current literature evaluating chronic kidney disease (CKD) prevalence and outcomes in TGD individuals on GAHT makes it difficult to assess any effects of GAHT on kidney function. Whether alterations in serum creatinine reflect changes in glomerular filtration rate or simply changes in muscle mass is unknown. Therefore, we propose a holistic framework to evaluate kidney function in TGD people. The framework focuses on kidney disease prevalence, risk factors, sex hormones, eGFR, other kidney function assessment tools, and the mitigation of health inequities in TGD people.

Evaluating the utility of a two-assay serological algorithm for hepatitis C screening in a low prevalence population.

INTRODUCTION: Screening for hepatitis C virus (HCV) is performed by testing for anti-HCV antibodies, which may yield false-positive results leading to additional testing and other downstream consequences for the patient. We report our experience in a low prevalence population (<0.05%) using a two-assay algorithm aimed at testing specimens with borderline or weak positive anti-HCV reactivity in the screening assay by a second anti-HCV assay prior to confirming positive anti-HCV results with RT-PCR. MATERIALS AND METHODS: Retrospective analysis of 58,908 plasma samples was obtained over a 5-year period. Samples were initially tested using the Elecsys Anti-HCV II assay (Roche Diagnostics), with borderline or weakly positive results (defined in our algorithm as a Roche cutoff index of 0.9-19.99) reflexively analyzed using the Architect Anti-HCV assay (Abbott Diagnostics). The Abbott anti-HCV results dictated the final anti-HCV interpretation for reflexed samples. RESULTS: Our testing algorithm resulted in 180 samples requiring second-line testing, with final anti-HCV results interpreted as 9% positive, 87% negative, and 4% indeterminate. The positive predictive value (PPV) of a weakly positive Roche result was 12%, which was significantly lower than the PPV using our two-assay approach (65%). CONCLUSIONS: The incorporation of a two-assay serological testing algorithm in a low prevalence population provides a cost-effective method of improving the PPV of HCV screening in specimens with borderline or weakly positive anti-HCV results.

SARS-CoV-2 Infection during Pregnancy in a Rural Midwest All-delivery Cohort and Associated Maternal and Neonatal Outcomes.

OBJECTIVE: This study aimed to estimate the prevalence of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) among pregnant patients at the time of delivery in a rural Midwest tertiary care hospital and to examine demographics, clinical factors, and maternal and neonatal outcomes associated with SARS-CoV-2 infection during pregnancy. STUDY DESIGN: This prospective cohort study included all delivering patients between May 1 and September 22, 2020 at the University of Iowa Hospitals and Clinics. Plasma SARS-CoV-2 antibody testing was performed. SARS-CoV-2 viral reverse-transcription polymerase chain reaction (RT-PCR) results and maternal and neonatal outcomes were collected from the electronic medical record. Data were analyzed using univariate statistical methods with clustering for multiple births. RESULTS: In total, 1,000 patients delivered between May 1 and September 22, 2020. Fifty-eight (5.8%) were SARS-CoV-2 antibody positive. Twenty-three also tested viral positive during pregnancy. Three of 1,000 (0.3%) were viral positive on admission but antibody negative. The median age was 30 years (interquartile range [IQR]: 26-33 years) and body mass index was 31.75 kg/m2 (IQR 27.7-37.5 kg/m2). The cesarean delivery rate was 34.0%. The study population was primarily white (71.6%); however, 41.0% of SARS-CoV-2 infected patients identified as Black, 18.0% as Hispanic/Latino, 3.3% as Native Hawaiian/Pacific Islander, and only 27.9% as White (p < 0.0001). SARS-CoV-2 infection was more likely in patients without private insurance (p = 0.0243). Adverse maternal and/or neonatal outcomes were not more likely in patients with evidence of infection during pregnancy. Two SARS-CoV-2 infected patients were admitted to the intensive care unit. There were no maternal deaths during the study period. CONCLUSION: In this largely rural Midwest population, 6.1% of delivering patients had evidence of past or current SARS-CoV-2 infection. Rates of SARS-CoV-2 during pregnancy were higher among racial and ethnic minorities and patients without private insurance. The SARS-CoV-2 infected patients and their neonates were not found to be at increased risk for adverse outcomes. KEY POINTS: · SARS-CoV-2 seroprevalence rate in pregnant population in Iowa is 5.8%.. · Infections are higher among minorities, non-English speakers, and patients without private insurance.. · No increased adverse maternal/neonatal outcomes observed for SARS-CoV-2 infected mothers..

Nonlinear protein binding of phenytoin in clinical practice: Development and validation of a mechanistic prediction model.

AIMS: To individualize treatment, phenytoin doses are adjusted based on free concentrations, either measured or calculated from total concentrations. As a mechanistic protein binding model may more accurately reflect the protein binding of phenytoin than the empirical Winter-Tozer equation that is routinely used for calculation of free concentrations, we aimed to develop and validate a mechanistic phenytoin protein binding model. METHODS: Data were extracted from routine clinical practice. A mechanistic drug protein binding model was developed using nonlinear mixed effects modelling in a development dataset. The predictive performance of the mechanistic model was then compared with the performance of the Winter-Tozer equation in 5 external datasets. RESULTS: We found that in the clinically relevant concentration range, phenytoin protein binding is not only affected by serum albumin concentrations and presence of severe renal dysfunction, but is also concentration dependent. Furthermore, the developed mechanistic model outperformed the Winter-Tozer equation in 4 out of 5 datasets in predicting free concentrations in various populations. CONCLUSIONS: Clinicians should be aware that the free fraction changes when phenytoin exposure changes. A mechanistic binding model may facilitate prediction of free phenytoin concentrations from total concentrations, for example for dose individualization in the clinic.

Accidental intoxications in toddlers: lack of cross-reactivity of vilazodone and its urinary metabolite M17 with drug of abuse screening immunoassays.

BACKGROUND: Vilazodone is an FDA approved medication used to treat major depressive disorder. The authors describe two cases of accidental vilazodone exposure in toddlers who presented with symptoms similar to amphetamine exposure and also with unexplained positive amphetamine urine immunoassay drug screens. Given a lack of published data on cross-reactivity of vilazodone and its metabolites with drug of abuse screening tests, the authors investigated drug of abuse immunoassay cross-reactivity of vilazodone and metabolites using computational and empirical approaches. METHODS: To ascertain the likelihood that vilazodone would cross-react with drug of abuse screening immunoassays, the authors assessed the two-dimensional (2D) similarity of the vilazodone parent molecule and known metabolites to an array of antigenic targets for urine immunoassay drug screens. To facilitate studies of the commercially unavailable M17 metabolite, it was prepared synthetically through a novel scheme. Urine and serum were spiked with vilazodone and M17 into urine (200-100,000 ng/mL) and serum (20-2000 ng/mL) samples and tested for cross-reactivity. RESULTS: Computational analysis using 2D similarity showed that vilazodone and metabolites have generally low similarity to antigenic targets of common drug of abuse screening immunoassays, predicting weak or no cross-reactivity. The M17 metabolite had 2D similarity to amphetamines and tricyclic antidepressants in a range similar to some other compounds exhibiting weak cross-reactivity on these immunoassays. Cross-reactivity testing was therefore performed on two different urine amphetamines immunoassays and a serum tricyclic antidepressant immunoassay. However, actual testing of cross reactivity for vilazodone and the M17 metabolite did not detect cross-reactivity for any urine amphetamines screen at concentrations up to 100,000 ng/mL and for a serum tricyclic antidepressants assays at concentrations up to 2000 ng/mL. CONCLUSION: While the vilazodone metabolite M17 has weak 2D structural similarity to amphetamines and tricyclic antidepressants, the current study did not demonstrate any experimental cross-reactivity with two different urine amphetamines immunoassays and a serum tricyclic antidepressant immunoassay. Vilazodone ingestions in young children present a diagnostic challenge in their similarity to amphetamine ingestions and the lack of routine laboratory tests for vilazodone. Further work is needed to understand the metabolic profile for vilazodone in children versus adults.

Clinical Utility of Ordered Pathology Blood Smear Reviews - an Overused Resource?

BACKGROUND: Blood smear reviews by pathologists (BSR) are ordered frequently at our institution, take time to evaluate, and result in a written report. Minimal research has been done regarding the amount of novel data reported and its clinical utility. METHODS: Detailed chart review was performed on BSR orders from January 1, 2015 to March 31, 2015 to assess reasons for smear review, if results were mentioned in the chart, if laboratory-driven reviews were already performed, and if novel, clinically influential data was reported. The trends in ordering was also evaluated. RESULTS: A total of 277 reviews were performed and were most commonly ordered to evaluate the presence of malignancy (43%), hemolysis (18%), and anemia (16%). For 130 of the 277 specimens, laboratory-driven smear review was already performed. The BSR smear review findings were not mentioned in the patient chart in 52% of cases. The report provided novel data in 187 cases (68%) which mainly were minor findings such as low levels of red blood cell abnormalities. The novel data appeared to influence clinical decision making in only 3 cases (1%). CONCLUSIONS: Although novel data are often reported, only rarely does it appear to be clinically significant and the information frequently overlaps with information already provided by laboratory-initiated smear reviews. Discussion with, and education of, clinical staff may increase appropriate utilization.

Unique Primary Care Needs of Transgender and Gender Non-Binary People.

It is important for the practicing primary care provider to become familiar with the unique health care needs for people who identify as transgender men, transgender women, and non-binary people, who are all within the scope of practice of a general obstetrician-gynecologist and other primary care providers. A review of the unique health needs and essential terminology is presented. This knowledge is a basic foundation to develop a welcoming and inclusive practice for people who are gender nonconforming. This fund of knowledge is essential the practicing primary care providers and support staff.

Developing an Inclusive and Welcoming LGBTQ Clinic.

People who identify as lesbian, gay, bisexual, transgender, queer, and questioning (LGBTQ) are underserved and face barriers to knowledgeable health care. Most health systems are ill prepared to provide care that addresses the needs of the LGBTQ community. Basic steps to developing an LGBTQ welcoming health care program are presented. It can be adapted to diverse health care models, from obstetrics and gynecology and other primary care services whether public or private and to hospitals and specialty clinics. This LGBTQ inclusive health care model was developed in collaboration with the LGBTQ community, a multidisciplinary team of health care providers, and professionals of Law and Information Technology.

Acetylation of lysine 109 modulates pregnane X receptor DNA binding and transcriptional activity.

Pregnane X receptor (PXR) is a major transcriptional regulator of xenobiotic metabolism and transport pathways in the liver and intestines, which are critical for protecting organisms against potentially harmful xenobiotic and endobiotic compounds. Inadvertent activation of drug metabolism pathways through PXR is known to contribute to drug resistance, adverse drug-drug interactions, and drug toxicity in humans. In both humans and rodents, PXR has been implicated in non-alcoholic fatty liver disease, diabetes, obesity, inflammatory bowel disease, and cancer. Because of PXR's important functions, it has been a therapeutic target of interest for a long time. More recent mechanistic studies have shown that PXR is modulated by multiple PTMs. Herein we provide the first investigation of the role of acetylation in modulating PXR activity. Through LC-MS/MS analysis, we identified lysine 109 (K109) in the hinge as PXR's major acetylation site. Using various biochemical and cell-based assays, we show that PXR's acetylation status and transcriptional activity are modulated by E1A binding protein (p300) and sirtuin 1 (SIRT1). Based on analysis of acetylation site mutants, we found that acetylation at K109 represses PXR transcriptional activity. The mechanism involves loss of RXRα dimerization and reduced binding to cognate DNA response elements. This mechanism may represent a promising therapeutic target using modulators of PXR acetylation levels. This article is part of a Special Issue entitled: Xenobiotic nuclear receptors: New Tricks for An Old Dog, edited by Dr. Wen Xie.

Impact of Endogenous and Exogenous Interferences on Clinical Chemistry Parameters Measured on Blood Gas Analyzers.

BACKGROUND: The prevalence of hemolysis, icterus, and lipemia (HIL) was determined for residual whole blood specimens analyzed for clinical chemistry parameters on blood gas analyzers. The frequency and potential impact of exogenous interference from iodide, salicylate, and thiocyanate (metabolite of sodium nitroprusside) on analysis of whole blood chloride was also assessed. METHODS: Over an approximately two month period at an academic medical center, indices for HIL were determined on Roche cobas c502 analyzers for 1,986 residual whole blood specimens that had been previously analyzed for clinical chemistry parameters on Radiometer ABL90 FLEX blood gas analyzers. To examine exogenous interferences, retrospective analysis was performed over multiple years to ascertain whether patient samples analyzed for whole blood chloride were potentially affected by interference from iodide, salicylate, or thiocyanate. RESULTS: Some degree of hemolysis (defined as hemolysis index of greater than 60) was present in 9.7% of the whole blood specimens. Increasing rates of hemolysis were associated with higher whole blood potassium concentrations. Nearly 60% of specimens with potassium concentrations between 6.0 and 6.9 mEq/L had hemolysis indices of 100 or greater, and 75% of specimens with a potassium concentration of 7.0 mEq/L or greater were severely hemolyzed (hemolysis index of 300 or greater). In contrast to the hemolysis results, icterus and lipemia were determined to have minimal impact on patient results. For the exogenous interferences, we did not identify any patient samples where elevated salicylate levels or pharmaceutical iodide administration overlapped with whole blood chloride analysis (out of 75,887 and 169,229 total chloride measurements, respectively). We did, however, find that for patients receiving nitroprusside therapy in the inpatient setting, whole blood chloride concentrations were significantly higher during nitroprusside therapy [106.7 +/- 6.2 mEq/L (mean, SD)] compared to before or after nitroprusside therapy (103.1 +/- 7.7 mEq/L). CONCLUSIONS: In this analysis of whole blood specimens, hemolysis is a common interference and likely to introduce meaningful biases, as illustrated with potassium analysis. Icterus, lipemia, salicylate, and iodide appear unlikely to cause clinically significant bias. Nitroprusside therapy introduced a slight rise in whole blood chloride concentrations that probably has minimal clinical significance.

Potential pitfalls of serum free light chain analysis to assess treatment response for multiple myeloma.

Response to treatment in patients with a plasma cell disorder is typically measured by evaluating the bone marrow and myeloma markers, including monoclonal protein spike and immunofixation (IFE) in blood and urine, and serum free light chains (sFLCs). Stringent complete response criteria for Multiple Myeloma (MM) patients require a normal FLC ratio and absence of clonal cells in bone marrow by immunohistochemistry or immunofluorescence. We performed a retrospective chart review to further evaluate these criteria. A total of 142 patient charts were analysed. Of these, 17 patients were found to have an abnormal sFLC ratio, but no other evidence of disease, including normal flow cytometry and normal fluorescence in situ hybridization (FISH) analysis on highly selected plasma cells. In all patients, the abnormal sFLC ratio was caused by abnormalities in the serum kappa light chains. These results suggest that current definitions may need to be revised to take aberrancies related to abnormal immune recovery into account.

Patterns of Drugs and Drug Metabolites Observed in Meconium: What Do They Mean?

BACKGROUND: Meconium drug testing is performed to detect potentially harmful drug exposures in a newborn. Interpretation of meconium drug testing results can be complicated based on the patterns and proportional concentrations of the drug(s) and/or drug metabolite(s) detected. METHODS: The objective of this study was to analyze meconium drug testing patterns in a de-identified dataset from a national reference laboratory (n = 76,631) and in a subset of the data, wherein specimens originated at a single academic medical center for which detailed chart review was possible (n = 3635). Meconium testing was performed using 11 immunoassay-based drug screens. Specimens that were positive for one or more drug screens were reflexed to corresponding confirmation tests performed by gas chromatography or liquid chromatography with mass spectrometric detection, targeted to identify and quantitate specific parent drug(s) and metabolite(s). RESULTS: The positivity rate was the highest for the cannabis metabolite 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (25.2%, n = 18,643), followed by opiates/oxycodone (23.2%, n = 17,778), amphetamine/methamphetamine (6.7%, n = 5134), cocaine metabolites (5.5%, n = 4205), methadone (5.3%, n = 4093), benzodiazepines (3.4%, n = 2603), barbiturates (1.1%, n = 834), propoxyphene (1.0%, n = 749), and phencyclidine (0.1%, n = 44). Based on documented pharmacy history, drugs administered to either the mother or newborn during the birth hospitalization were detected in meconium, providing evidence that drugs can be incorporated into meconium rapidly. Drugs administered directly to the newborn after birth were recovered in meconium as both parent drug and metabolites, providing evidence of neonatal metabolism. Overall, patterns observed in meconium exhibited many similarities to those patterns commonly reported with urine drug testing. CONCLUSIONS: Interpretation of meconium drug testing results requires comparison of results with clinical and analytical expectations, including maternal admissions to drug use, pharmacy history, recognized metabolic patterns for drugs of interest, cutoff concentrations, and other performance characteristics of the test. Concentrations of drug(s) and drug metabolites(s) may not reliably predict timing of drug use, extent of drug use, or frequency of drug exposures.

Therapeutic Drug Monitoring of Pentobarbital: Experience at an Academic Medical Center.

BACKGROUND: Pentobarbital is used for management of intractable seizures and for reducing elevated intracranial pressure. Dosing of pentobarbital can be aided by therapeutic drug monitoring (TDM). There is no commercially available automated assay for measurement of pentobarbital serum/plasma concentrations; consequently, chromatography-based assays are often used. METHODS: Pentobarbital TDM was studied over a 14-year period at an academic medical center. 154 patients (94 adult, 60 pediatric) were identified who had pentobarbital levels ordered at least once during a hospital encounter. Chart review included patient diagnosis, indication for pentobarbital therapy, recent or concomitant medication with other barbiturates, patient disposition, organ donation, pentobarbital dosing changes, and neurosurgical procedures. Pentobarbital serum/plasma concentrations were determined on an automated clinical chemistry platform with a laboratory-developed test adapted from a urine barbiturates immunoassay. RESULTS: Chart review showed therapeutic use of pentobarbital generally consistent with previously published literature. The most common errors observed involved confusion in barbiturate names (eg, mix-up of pentobarbital and phenobarbital in test ordering or in provider notes) that seemed to have minimal impact on TDM effectiveness, with pentobarbital serum/plasma concentrations generally within target ranges. The laboratory-developed pentobarbital immunoassay showed cross-reactivity with phenobarbital and butalbital that was eliminated by alkaline and heat pretreatment. The immunoassay was linear to 20 mcg/mL and correlated closely with gas chromatography-mass spectrometry measurements at a reference laboratory. CONCLUSIONS: Pentobarbital TDM can be performed by immunoassay on an automated clinical chemistry platform, providing an alternative to chromatography-based methods. Confusion in barbiturate names is common, especially pentobarbital and phenobarbital.

POSITIVE TEST FOR ANTITHYROGLOBULIN ANTIBODIES DUE TO ADMINISTRATION OF IMMUNOGLOBULIN REPLACEMENT THERAPY IN A PATIENT WITH THYROID CANCER.

OBJECTIVE: Thyroglobulin (Tg) is used as a tumor marker to monitor differentiated thyroid cancer progression and recurrence. However, Tg measured by standard immunoassay (IMA) is not a reliable marker in the presence of anti-Tg antibodies (TgAbs) due to interference that may result in either false-positive or false-negative results. TgAbs levels can be high due to thyroid cancer and also exogenous immunoglobulin (Ig) administration, thus making it difficult to identify differentiated thyroid cancer recurrence. METHODS: We present an example of elevated TgAbs due to subcutaneous Ig (SCIg) administration in a patient with thyroid cancer. RESULTS: A 57-year-old male was diagnosed with stage I papillary thyroid cancer (PTC). His TgAbs were negative prior to the diagnosis of thyroid cancer and became positive after thyroidectomy and radioactive iodine administration. A detailed work-up including a whole body scan did not reveal recurrent disease. He had been diagnosed with common variable immune deficiency (CVID) and dermatomyositis at the age of 50 and was started on immunoglobulin (Ig) replacement therapy shortly after diagnosis. His Tg was negative when assessed with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Therefore, elevated TgAb titers were attributed to concomitant SCIg treatment. We also demonstrated that SCIg treatment had TgAb activity that was removed by protein A column treatment. Dilutions of SCIg medication also caused positive IgG serologies for cytomegalovirus and herpes simplex, measles, mumps, rubella, and varicella zoster viruses. CONCLUSION: An exogenous source of TgAbs from SCIg led to extensive imaging work-up to assess for PTC recurrence. LC-MS/MS is a conceptually attractive approach to overcome TgAb interference with Tg IMA measurement.

Impact of add-on laboratory testing at an academic medical center: a five year retrospective study.

BACKGROUND: Clinical laboratories frequently receive orders to perform additional tests on existing specimens ('add-ons'). Previous studies have examined add-on ordering patterns over short periods of time. The objective of this study was to analyze add-on ordering patterns over an extended time period. We also analyzed the impact of a robotic specimen archival/retrieval system on add-on testing procedure and manual effort. METHODS: In this retrospective study at an academic medical center, electronic health records from were searched to obtain all add-on orders that were placed in the time period of May 2, 2009 to December 31, 2014. RESULTS: During the time period of retrospective study, 880,359 add-on tests were ordered on 96,244 different patients. Add-on testing comprised 3.3 % of total test volumes. There were 443,411 unique ordering instances, leading to an average of 1.99 add-on tests per instance. Some patients had multiple episodes of add-on test orders at different points in time, leading to an average of 9.15 add-on tests per patient. The majority of add-on orders were for chemistry tests (78.8 % of total add-ons) with the next most frequent being hematology and coagulation tests (11.2 % of total add-ons). Inpatient orders accounted for 66.8 % of total add-on orders, while the emergency department and outpatient clinics had 14.8 % and 18.4 % of total add-on orders, respectively. The majority of add-ons were placed within 8 hours (87.3 %) and nearly all by 24 hours (96.8 %). Nearly 100 % of add-on orders within the emergency department were placed within 8 hours. The introduction of a robotic specimen archival/retrieval unit saved an average of 2.75 minutes of laboratory staff manual time per unique add-on order. This translates to 24.1 hours/day less manual effort in dealing with add-on orders. CONCLUSION: Our study reflects the previous literature in showing that add-on orders significantly impact the workload of the clinical laboratory. The majority of add-on orders are clinical chemistry tests, and most add-on orders occur within 24 hours of original specimen collection. Robotic specimen archival/retrieval units can reduce manual effort in the clinical laboratory associated with add-on orders.

Promoting improved utilization of laboratory testing through changes in an electronic medical record: experience at an academic medical center.

This case study over time describes five years of experience with interventions to improve laboratory test utilization at an academic medical center. The high-frequency laboratory tests showing the biggest declines in order volume post intervention were serum albumin (36%) and erythrocyte sedimentation rate (17%). Introduction of restrictions for 170 high-cost send-out tests resulted in a 23% decline in order volume. Targeted interventions reduced mis-orders involving several "look-alike" tests: 1,25-dihydroxyvitamin D, 25-hydroxyvitamin D; manganese, magnesium; beta-2-glycoprotein, beta-2-microglobulin. Lastly, targeted alerts reduced duplicate orders of germline genetic testing and orders of hepatitis B surface antigen within 2 weeks of hepatitis B vaccination.

Detection of neonatal drug exposure using umbilical cord tissue and liquid chromatography time-of-flight mass spectrometry.

BACKGROUND: A method for qualitative detection of 57 drugs and metabolites in umbilical cord tissue using liquid chromatography time-of-flight (TOF) mass spectrometry is described. METHODS: Results from 32 deidentified positive specimens analyzed by an outside laboratory using "screen with reflex to confirmation" testing were compared with TOF results. In addition, 57 umbilical cord tissue specimens paired with corresponding chart review data and 37 with meconium test results were analyzed by TOF. Urine drug test results from mother (n = 18) and neonate (n = 30) were included if available. Cutoff concentrations, recovery, and matrix effects were determined by analyzing fortified drug-free cord tissue and negative specimens. Cutoffs (in nanograms per gram) ranged from 1 to 10 for opioids and opioid antagonists, 5-10 for benzodiazepines and nonbenzodiazepine hypnotics, 20-40 for barbiturates, 8 for stimulants, and 4 for phencyclidine. Adequate sensitivity for the detection of cannabis exposure could not be realized with this method. CONCLUSIONS: Liquid chromatography time-of-flight mass spectrometry can provide accurate and sensitive detection of in utero drug exposure using umbilical cord tissue.