Consensus Considerations and Good Practice Points for Use of Continuous Glucose Monitoring Systems in Hospital Settings.

Continuous glucose monitoring (CGM) systems provide frequent glucose measurements in interstitial fluid and have been used widely in ambulatory settings for diabetes management. During the coronavirus disease 2019 (COVID-19) pandemic, regulators in the U.S.

Monitoring tacrolimus toxicity following Paxlovid administration in a liver transplant patient.

Maintaining therapeutic plasma tacrolimus concentrations is essential for mitigating potential solid organ transplant rejection and preventing toxic adverse side effects. While patients can benefit greatly from tacrolimus therapy, co-administration of drugs such as Paxlovid (nirmatrelvir/ritonavir) place patients at serious risk for drug interactions and harm. Here we present a case of tacrolimus toxicity following Paxlovid administration in a liver transplant patient.

Analytical Performance Evaluation of Three Point-of-Care CBC Analyzers for Management of Clozapine Therapy in Ambulatory Psychiatry Clinics.

Background: Clozapine is a first-line therapy and the only FDA-approved drug for patients with treatment-resistant schizophrenia (TRS). However, frequent measurement of absolute neutrophil count (ANC) is required to monitor for potential adverse severe neutropenia from clozapine therapy. We evaluated 3 point-of-care (POC) instruments that perform the complete blood count (CBC) with differential to assess their analytical performance and potential to meet the clinical need for clozapine therapy management.

Current Issues in Blood Gas Analysis.

Background: Blood gas analysis constitutes one of the most widely used tests, especially in critical care settings such as intensive care units, emergency departments, and operating rooms. Blood gas results are key for assessing acid-base balance and ventilatory control in critically ill patients. Because blood gas analysis plays a vital role in management of critically ill patients, this testing is frequently conducted at the point-of-care by users with various educational backgrounds across different hospital departments.

Activated clotting time in inpatient diagnostic and interventional settings.

Monitoring for the anticoagulant effect of unfractionated (UFH) at the point of care using activated clotting time in real time is vital where risk of thrombosis is high. Although monitoring UFH effect is a routine and important task, changing from one ACT instrument type or technology to another must be preceded by a clinical and statistical evaluation to determine the suitability and repeatability and establish normal and treatable ranges of this newer instrument. In this multi-center prospective evaluation we tested 1236 paired ACT+ samples, and 463 paired ACT-LR samples (1699 total) from enrolled study subjects.

Comparative Analyses of Three Point-of-Care Urine Drug Test Devices' Performance Characteristics for Use in Ambulatory Clinic Settings.

Background: Urine drug testing (UDT) is a standard practice used for monitoring controlled and illicit substances in ambulatory care patients. Point-of-care (POC) UDTs are useful tools that allow for drug identification within minutes, providing rapid and objective diagnostic assistance for clinicians. The objective of this study was to evaluate the performance characteristics of 3 different POC UDT devices compared to reference methods.

Characterization of biotin interference in 21 Vitros 5600 immunoassays and risk mitigation for patient safety at a large academic medical center.

Background: Biotin and streptavidin are commonly used reagents in clinical immunoassays. Several cases of biotin interference with immunoassay testing for patients taking biotin supplements have been reported, yet, not all analytes and platforms susceptible to biotin interference have been characterized. The objectives of this study are to characterize biotin interference with 21 immunoassays using the Ortho Clinical Diagnostics Vitros 5600, evaluate a biotin-depletion method, and apply risk mitigation strategies for biotin interference during routine clinical testing at our institution.

Suspected Testosterone-Producing Tumor in a Patient Taking Biotin Supplements.

A perimenopausal woman presented with palpitations, hirsutism, and inability to lose weight. Laboratory tests revealed an unusual endocrine hormonal profile including pituitary hormones (TSH, ACTH, and prolactin) below reference intervals and gonadal (testosterone) and adrenal (cortisol) hormones above reference intervals. Ultimately, after a comprehensive workup including a scheduled surgical procedure, abnormal laboratories were determined due to biotin interference.

Reference intervals and diagnostic ranges for serum free κ and free λ immunoglobulin light chains vary by instrument platform: Implications for classification of patient results in a multi-center study.

Background: Serum free light chain (FLC) immunoglobulins are key biomarkers that aid in the diagnosis, prognosis and assessment of treatment response in patients with plasma cell disorders (PCD). Here we investigated the transference of manufacturer's reported κFLC, λFLC and κ to λ FLC reference intervals (RI) and established de novo FLC RI and diagnostic ranges on four instruments at three academic medical centers. In addition, we also compared the classification of patient FLC results using manufacturer's versus established RIs and diagnostic ranges.

Using a simulation model to assess risk of false negative point-of-care urinary human chorionic gonadotropin device results due to high-dose hook interference.

Background: It is unclear if the point-of-care (POC) Clinitest hCG device is subject to high-dose hook interference from physiological concentrations of intact human chorionic gonadotropin (hCG), β-core fragment of hCG (hCGβcf), and hCG free β-subunit (hCGβ) found in urine during pregnancy. We used a simulation model to address this question and related our findings to our institution's pregnant population in order to assess risk for potential false-negative hCG results.

Methods: The expected distribution of days relative to ovulation during routine POC hCG testing was estimated from 182 patients.

Utilization of assay performance characteristics to estimate hemoglobin A1c result reliability.

Background: Allowable total error (TE(a)) goals for hemoglobin (Hb) A(1c) require minimal assay imprecision and bias and implementation of a robust QC monitoring program. Here, we compare the combined influence on the risk of reporting unreliable results of TE(a) goals, a routine QC practice, and assay performance characteristics of 6 Hb A(1c) instruments across 4 academic medical centers.

Methods: The CLSI protocols EP-5 and EP-9 were applied to investigate Hb A(1c) result imprecision and bias on the Variant II Turbo and Variant II (Bio-Rad), G8 (Tosoh), Capillarys 2 Flex Piercing (Sebia), COBAS Integra 800 (Roche), and DCA Vantage (Siemens).

Osteoporosis in men.

Osteoporosis in men causes significant morbidity and mortality. Bone health declines gradually, often insidiously; and in light of the advancing aging population poses a serious public health issue that is not well recognized. Studies of the past decade have expanded our understanding of the events within, as well as the regulation of, bone remodeling and provided better insight into the physiology and pathophysiology specific to the adult male skeleton.

Reducing analytical variation between point-of-care and laboratory HbA1c testing.

Background: Point-of-care (POC) HbA1c testing allows for timely treatment changes, improved glycemic control, and patient and provider satisfaction. Substantial variation between POC and laboratory HbA1c results has been reported. At our university hospital diabetes clinic, we observed significant negative bias in HbA1c with the DCA Vantage (Siemens Healthcare Diagnostics, Tarrytown, NY, USA) compared with the Tosoh G8 HPLC laboratory analyzer (Tosoh Bioscience, San Francisco, CA, USA).