The yield of routine laboratory examination in osteoporosis evaluation in primary care.

This study evaluated the yield of routine laboratory examination in a large population of older women in primary care. The prevalence of laboratory abnormalities was low and the clinical consequences in follow-up were limited. There was a weak association of laboratory abnormalities with osteoporosis but no association with vertebral fractures and recent fractures. PURPOSE: Most osteoporosis guidelines advice routine laboratory examination. We have investigated the yield of laboratory examinations in facture risk evaluation of elderly women in primary care. METHODS: We assessed the prevalence of laboratory abnormalities and their association with risk factors for fractures, recent fractures, low bone mineral density (BMD), and prevalent vertebral fracture in 8996 women ≥ 65 years of age participating in a primary care fracture risk screening study. In a sample of 2208 of these participants, we also evaluated the medical consequences in the medical records during a follow-up period of ≥ 1 year. RESULTS: Vitamin D deficiency (< 30 nmol/L) was present in 13% and insufficiency (< 50 nmol/L) in 43% of the study sample. The prevalence of other laboratory abnormalities (ESR, calcium, creatinine, FT4) was 4.6% in women with risk factors for fractures, 6.1% in women with low BMD (T-score ≤ - 2.5), 6.0% after a prevalent vertebral fracture, 5.2% after a recent fracture and 2.6% in the absence of important risk factors for fractures. Laboratory abnormalities other than vitamin D were associated with low BMD (OR 1.4, 95%CI 1.1-1.8) but not with prevalent vertebral fractures nor recent fractures. Low BMD was associated with renal failure (OR 2.0, 95%CI 1.3-3.4), vitamin D insufficiency (OR 1.2, 95%CI 1.0-1.3) and deficiency (OR 1.3, 95%CI 1.1-.5). In the follow-up period, 82% of the laboratory abnormalities did not result in a new diagnosis or treatment reported in the medical records. CONCLUSIONS: We identified a low prevalence of laboratory abnormalities in a primary care population of older women and the majority of these findings had no medical consequences.

Verifying measurements on Siemens Atellica® instruments using clinically acceptable analytical performance specifications.

Measurements on clinical chemistry analysers must be verified to demonstrate applicability to their intended clinical use. We verified the performance of measurements on the Siemens Atellica® Solution chemistry analysers against the clinically acceptable analytical performance specifications, CAAPS, including the component of intra-individual biological variation, CVI. The relative standard uncertainty of measurement, i.e. analytical variation, CVA, was estimated for six example measurands, haemoglobin A1c in whole blood (B-HbA1c), albumin in urine (U-Alb), and the following measurands in plasma: sodium (P-Na), pancreatic amylase (P-AmylP), low-density lipoprotein cholesterol (P-LDL-C), and creatinine (P-Crea). Experimental CVA was calculated from single-instrument imprecision using control samples, variation between measurements on parallel instruments, and estimation of bias with pooled patient specimens. Each obtained CVA was compared with previously developed CAAPS. The calculated CVA was 1.4% for B-HbA1c (CAAPS 1.9% for single diagnostic testing, CAAPS 2.0% for monitoring after duplicate tests; IFCC units), 10.9% for U-Alb (CAAPS 44.9%), 1.2% for P-Na (CAAPS 0.6%, after triplicate testing 1.5%), 8.2% for P-AmylP (CAAPS 22.9%). The CVA was 4.9% for P-LDL-C (CAAPS for cardiovascular risk stratification 4.9% after four replicates), and 4.2% for P-Crea (CAAPS 8.0%). Three of the six measurands fulfilled the estimated clinical need. Results from P-Na measurements indicate a general need for improving the P-Na assays for emergency patients. It is necessary to consider CVI when creating diagnostic targets for laboratory tests, as emphasised by the CAAPS estimates of B-HbA1c and P-LDL-C.

Analytical validation of 39 clinical chemistry tests and 17 immunoassays on the Alinity analytical system.

The aim of this study was to perform the analytical validation of Alinity c and i analyzers (Abbott Laboratories, Chicago, IL, USA) for 39 clinical chemistry tests and 17 immunoassays. Precision was evaluated at least at two concentration levels for 5 days in quintuplicate, following CLSI EP15-A3. Method comparison included parallel analysis of leftover routine samples on Alinity analyzers and the previously used Cobas c501 and e601 (Roche Diagnostics, Mannheim, Germany). Linearity was tested by preparing sequential sample dilutions with high analyte concentration, following the CLSI EP6 document. For clinical chemistry tests, within-run coefficients of variation (CV) were up to 6.0% (beta-2-microglobulin), while between-run CVs up to 5.4% (immunoglobulin M). Among immunoassays, the highest within-run CV was obtained for vitamin B12 (6.9%), while between-run for CA 19-9 (4.3%). Complete agreement with Roche analyzers was observed for 16 (41%) clinical chemistry assays and 6 (35%) immunoassays. Half of all evaluated assays did not meet the desirable biological variation criteria for bias, being especially exceeded for alpha1-antitrypsin, apolipoprotein A1, ceruloplasmin, complement C3 and C4, hemoglobin A1c, lipoprotein (a) and myoglobin, as well as some tumor markers (CA 125, CEA, fPSA, AFP, and ferritin), hormones (cortisol, DHEA-S, insulin) and vitamins (25-OHD). Linearity in the tested ranges was confirmed. Overall, this study revealed that precision criteria derived from manufacturer's claims were not satisfied for all assays while comparison study for some assays yielded differences that imply the need for additional assay evaluation prior to introduction into routine practice.

The Impact of a Standardized Pre-visit Laboratory Testing Panel in the Internal Medicine Outpatient Clinic: a Controlled "On-Off" Trial.

BACKGROUND: In several settings, a shorter time to diagnosis has been shown to lead to improved clinical outcomes. The implementation of a rapid laboratory testing allows for a pre-visit testing in the outpatient clinic, meaning that test results are available during the first outpatient visit. OBJECTIVE: To determine whether the pre-visit laboratory testing leads to a shorter time to diagnosis in the general internal medicine outpatient clinic. DESIGN: An "on-off" trial, allocating subjects to one of two treatment arms in consecutive alternating blocks. PARTICIPANTS: All new referrals to the internal medicine outpatient clinic of a university hospital were included, excluding second opinions. A total of 595 patients were eligible; one person declined to participate, leaving data from 594 patients for analysis. INTERVENTION: In the intervention group, patients had a standardized pre-visit laboratory testing before the first visit. MAIN MEASURES: The primary outcome was the time to diagnosis. Secondary outcomes were the correctness of the preliminary diagnosis on the first day, health care utilization, and patient and physician satisfaction. KEY RESULTS: There was no difference in time to diagnosis between the two groups (median 35 days vs 35 days; hazard ratio 1.03 [0.87-1.22]; p = .71). The pre-visit testing group had higher proportions of both correct preliminary diagnoses on day 1 (24% vs 14%; p = .003) and diagnostic workups being completed on day 1 (10% vs 3%; p < .001). The intervention group had more laboratory tests done (50.0 [interquartile range (IQR) 39.0-69.0] vs 43.0 [IQR 31.0-68.5]; p < .001). Otherwise, there were no differences between the groups. CONCLUSIONS: Pre-visit testing did not lead to a shorter overall time to diagnosis. However, a greater proportion of patients had a correct diagnosis on the first day. Further studies should focus on customizing pre-visit laboratory panels, to improve their efficacy. TRIAL REGISTRATION: NL5009.

Reference intervals for 12 clinical laboratory tests in a Danish population: The Lolland-Falster Health Study.

Reference intervals (RIs), developed as part of the Nordic Reference Interval Project 2000 (NORIP) are widely used in most European laboratories. We aimed to examine the validity of the NORIP RIs by establishing RIs for 12 frequently used laboratory tests based on data from a local Danish population and compare these local RIs with the NORIP RIs. Using an a posteriori direct sampling approach, blood sample data were assessed from 11,138 participants aged 18+ years in the Lolland-Falster Health Study (LOFUS), of whom 2154 turned out to meet criteria for being healthy for inclusion in establishing RIs according to the NORIP methodology. The 2.5th and 97.5th percentiles were calculated for alanine aminotransferase (ALAT), albumin, alkaline phosphatase, bilirubin, creatinine, hemoglobin, high-density lipoprotein cholesterol, iron, low-density lipoprotein cholesterol, thrombocytes, total cholesterol, and triglycerides. When comparing our estimates with the NORIP, the lower reference limits (RLs) for bilirubin and iron were lower, and higher for ALAT, thrombocytes and triglycerides. Upper RLs were lower for albumin (males and females ≥70 years), bilirubin and iron, but higher for alkaline phosphatase, triglycerides and for creatinine in men. In LOFUS, approximately 20% of the participants were healthy and qualified for inclusion in the establishment of RIs. Several of the local RIs differed from the NORIP RIs.

Change in HbA1c concentration as decision parameter for frequency of HbA1c measurement.

Hemoglobin A1c (HbA1c) is a long-term measure for glucose concentration in plasma. Since its introduction as a diabetes monitoring tool, and its more recent application as a diagnostic tool, the number of measurements of HbA1c have risen dramatically. However, HbA1c change is slow, so repeating measurements should not be done too often. We use a large, unfiltered dataset from 52,017 patients to determine the possible rate of change in HbA1c concentration. In our laboratory, the critical difference between HbA1c measurements is 8.5%. Our data show that a 1-unit HbA1c rise takes 4 weeks to occur, hence, at a HbA1c concentration around 50 mmol/mol Hgb, a critically increased HbA1c concentration cannot be determined until after 16 weeks. Conversely a critically lower HbA1c can manifest itself after 2 weeks, but after 7 weeks the dropping tendency stops. The amount of measurements that can be cancelled because they were taken sooner than 16 weeks is 23 percent.

Survey on common reference intervals for general chemistry analytes in Hong Kong.

INTRODUCTION: Reference intervals (RIs) are essential tool for proper interpretation of results. There is a global trend towards implementing common RIs to avoid confusion and enhance patient management across different laboratories. However, local practices with respect to RIs lack harmonisation. METHODS: We have conducted the first local survey regarding RIs for 14 general chemistry analytes in 10 chemical pathology laboratories that employ four different analytical platforms (Abbott Architect, Beckman Coulter AU, Roche Cobas, and Siemens Dimension EXL). Analytical bias was assessed by an inter-laboratory results comparison of external quality assurance programmes. RESULTS: Sufficient inter-laboratory and inter-platform agreement regarding the 10 analytes (albumin, alanine aminotransferase, aspartate aminotransferase, chloride, gamma-glutamyl transferase, phosphate, potassium, sodium, total protein, and urea) were demonstrated. However, the RIs were heterogeneous across all laboratories, with percentage differences of the upper RI value of up to 47% for aspartate aminotransferase (absolute difference of 16 U/L), 29% for urea (1.8 mmol/L), and 18% for potassium (0.8 mmol/L). The percentage difference between lower RI values was up to 24% for urea (0.6 mmol/L), 22% for phosphate (0.16 mmol/L), and 8% for total protein (5 g/L). The coefficients of variation of the upper RI values of potassium and sodium were 1.2 times and 1.0 times of their corresponding between-subject biological variation, respectively, representing unnecessary variations that are overlooked and unchecked in current practice. CONCLUSIONS: We recommend the use of common RIs for general chemistry analytes in Hong Kong to prevent interpreter confusion, improve electronic data transfer, and unite laboratory practice. This is the first local study on this topic, and our data can lay the groundwork for increasing harmonisation of RIs across more laboratory tests.

Approach to the interpretation of unexpected laboratory results arising in the care of patients with inborn errors of metabolism (IEM).

Endocrinologists may encounter abnormal results in routine laboratory tests while caring for patients with inborn errors of metabolism. This article provides a framework for understanding these abnormalities as: a) part of the pathophysiology of the exceptional disease, b) exceptional laboratory errors related to the exceptional disease, or c) routine laboratory errors to which any patient sample is susceptible.

Pediatric reference intervals for general clinical chemistry components - merging of studies from Denmark and Sweden.

BACKGROUND: Reference intervals are crucial tools aiding clinicians when making medical decisions. However, for children such values often are lacking or incomplete. The present study combines data from separate pediatric reference interval studies of Denmark and Sweden in order to increase sample size and to include also pre-school children who were lacking in the Danish study. METHODS: Results from two separate studies including 1988 healthy children and adolescents aged 6 months to 18 years of age were merged and recalculated. Eighteen general clinical chemistry components were measured on Abbott and Roche platforms. To facilitate commutability, the NFKK Reference Serum X was used. RESULTS: Age- and gender-specific pediatric reference intervals were defined by calculating 2.5 and 97.5 percentiles. CONCLUSION: The data generated are primarily applicable to a Nordic population, but could be used by any laboratory if validated for the local patient population.

Ricin Poisoning after Oral Ingestion of Castor Beans: A Case Report and Review of the Literature and Laboratory Testing.

BACKGROUND: Ricin is a protein toxin derived from the castor bean plant Ricinus communis. Several cases secondary to its consumption have been published and, more recently, its use as a potential bioterrorism agent has also been reported. Oral absorption of ricin is highly erratic, leading to a wide spectrum of symptoms. In addition, conventional urine drug screening tests will not be able to detect this compound, posing a diagnostic challenge. CASE REPORT: A male teenager intended to die by ingesting 200 castor beans after mixing and blending them with juice. Eight hours later, he presented with weakness, light-headedness, nausea, and vomiting and sought medical treatment. The patient was admitted and treated conservatively. An immune-based standard urine toxicology drug screen panel was reported as negative. A comprehensive untargeted urine drug screen test showed the presence of ricinine, a surrogate marker of ricin intoxication. He was transferred to the psychiatric service 3 days after admission. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: This case highlights the importance of knowing the peculiar pharmacokinetic properties of ricin after oral ingestion of castor beans and toxin release through mastication. Emergency physicians should be aware that oral absorption of ricin is dependent on several factors, such type and size of seeds and the geographic harvesting region, making it extremely difficult to estimate its lethality based solely on the number of ingested beans. Finally, comprehensive untargeted urine drug screening testing is highly valuable as a diagnostic tool in this context.

Estimation of the uncertainty of analyte concentration from the measurement uncertainty.

Ligand-binding assays, such as immunoassays, are usually analysed using standard curves based on the four-parameter and five-parameter logistic models. An estimate of the uncertainty of an analyte concentration obtained from such curves is needed for confidence intervals or precision profiles. Using a numerical simulation approach, it is shown that the uncertainty of the analyte concentration estimate becomes significant at the extremes of the concentration range and that this is affected significantly by the steepness of the standard curve. We also provide expressions for the coefficient of variation of the analyte concentration estimate from which confidence intervals and the precision profile can be obtained. Using three examples, we show that the expressions perform well.

Can physician laboratory-test requests be influenced by interventions?

BACKGROUND: Laboratory tests affect healthcare costs and unnecessary test requests can thus be a concern. We studied whether it was possible to influence physician laboratory-test requests using four structured interventions: introduction of clinical guidelines, education, feedback, and reminder letters. The interventions occurred at different times at Landspítali University Hospital, Reykjavik, Iceland. Akureyri Hospital, northern Iceland, was used as a control, since no formal interventions were introduced there. MATERIALS AND METHODS: Six types of laboratory tests were analyzed. The relative risk of a laboratory test being conducted at Landspítali University Hospital compared to Akureyri Hospital was calculated for various points in time, as well as the associated 95% confidence intervals. The primary estimates compare the pre- and post-intervention periods (2007-2009 vs. 2010-2013), but also on a monthly basis in order to observe the trends in greater detail. RESULTS: Interventions at Landspítali University Hospital led to a significant reduction in the average number of laboratory tests (12-52%, p < 0.001) compared with Akureyri Hospital. Relative risk coefficients of laboratory tests at Landspítali University Hospital (LUH) compared to Akureyri Hospital (AH) were calculated pre- and post-guidelines, the relative risk for ASAT, CRP and GGT fell markedly, while ALAT and ALP tests did not show a significant decrease. Relative risk for a blood culture test in the period after the guidelines was statistically significantly increased. CONCLUSION: It is possible to influence physician laboratory-test requests using multifaceted interventions that include continuous monitoring and follow-up.

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.

Effects of reverse osmosis membrane replacement of pure water system on clinical chemistry and immunoassay in clinical laboratory.

Introduction: Reverse osmosis (RO) membrane, key component of water-purifying equipment, is often stored in protection fluid containing substances such as glycerol, which may contaminate the water at replacement. This study aims to explore the effects of RO membrane replacement on clinical chemistry and immunoassay, particularly triglyceride (TG), providing reference for managing test interference caused by RO membrane replacement. Materials and methods: The RO membrane of water-purifying equipment A, which provided water to C16000 biochemistry analyzer (Abbott Laboratories, Abbott Park, USA) and E801 electrochemiluminescence analyzer (Roche, Basel, Switzerland), was replaced. Water resistivity was recorded, and quality control (QC) tests were performed on C16000 and E801. Moreover, TG was measured in 29 of selected serum samples on C16000 at 0.5h and 10.5h after RO membrane replacement and on reference biochemistry analyzer BS2000M (Mindray Biomedical Electronics Co., Shenzhen, China), which was connected to water-purifying equipment B without RO membrane replacement. Finally, blank, calibrator 1 and calibrator 2 of TG reagent were measured on C16000 before and at 0.5h, 2.5h and 10.5h after RO membrane replacement. All statistical analyses of data were done using GraphPad Prism (GraphPad Software Inc., San Diego, USA), and a value of P < 0.05 was considered statistically significant. Results: After RO membrane replacement, all QC results of clinical chemistry and immune tests passed except TG that showed positive bias of 536% and 371% at two levels, respectively. Moreover, TG results of the same serum samples were significantly higher at 0.5h than 10.5h after RO membrane replacement. Meanwhile, there was worse agreement and correlation of TG results between C16000 and BS2000M at 0.5h than 10.5h after replacement. Furthermore, the absorbance of TG blank, calibrator 1 and calibrator 2 was significantly higher at 0.5h and 2.5h after replacement than before replacement, and the absorbance gradually returned to normal value at 10.5h after replacement. Conclusions: Replacement of RO membrane could cause significant interference to TG test while have no effects on other laboratory tests performed in the study, which may be due to glycerol contamination. Our data provides important reference for management of test interference caused by RO membrane replacement. Clinical laboratory should observe the effects of RO membrane replacement on laboratory tests through both water quality monitoring and QC detection.

Reference Intervals for Blood Chemistry Parameters in the Pakistani Population: A Systematic Review of Published Literature.

Background: Reference intervals (RI) are a vital part of information provided with laboratory results. It is recommended that RI should be established by each laboratory following pre-laid guidelines. In this systemic review, we aim to comprehensively analyze and summarize all the published literature about establishment of RI for biochemical parameters in Pakistani population. Methodology: We conducted a comprehensive search using Medline (PubMed interface) and PakMediNet literature, adhering to PRISMA guidelines. The search spanned from January 1984 to February 2024. All studies done for establishment of RI of biochemical parameters were included, while were nonhuman studies, case studies, preprints, no full text and articles in languages other than English were excluded. Rigorous evaluation ensured the robustness of their study analysis. Results: Database search reveled 161 studies, 30 were analyzed as per inclusion criteria. The accumulated sample size of the studies comprised 108,563 individuals. Most of the studies were carried out on adults in Punjab and Sindh provinces. A wide variation was noted among the RIs established and units used in each study. Gaps were identified regarding description of healthy population, patient preparation sample handing and quality control. Conclusion: In this review, critical gaps in data, methodology and reporting were identified. To enhance future studies, researchers should clearly define healthy populations, incorporate rigorous sample handling and quality control, and collaborate across centers.

Comparison of lipemia interference created with native lipemic material and intravenous lipid emulsion in emergency laboratory tests.

Introduction: This study aimed to investigate the effects of lipemia on clinical chemistry and coagulation parameters in native ultralipemic (NULM) and intravenous lipid emulsion (IVLE) spiked samples. Materials and methods: The evaluation of biochemistry (photometric, ion-selective electrode, immunoturbidimetric method), cardiac (electrochemiluminescence immunoassay method) and coagulation (the viscosity-based mechanical method for prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen and the immunoturbidimetric method for D-dimer) parameters were conducted. In addition to the main pools, five pools were prepared for both types of lipemia, each with triglyceride (TG) concentrations of approximately 2.8, 5.7, 11.3, 17.0 and 22.6 mmol/L. All parameters' mean differences (MD%) were presented as interferographs and compared with the desirable specification for the inaccuracy (bias%). Data were also evaluated by repeated measures of ANOVA. Results: Prothrombin time and APTT showed no clinically relevant interference in IVLE-added pools but were negatively affected in NULM pools(P < 0.001 in both parameters). For biochemistry, the most striking difference was seen for CRP; it is up to 134 MD% value with NULM (P < 0.001) at the highest TG concentration, whereas it was up to - 2.49 MD% value with IVLE (P = 0.009). Albumin was affected negatively upward of 5.7 mmol/L TG with IVLE, while there was no effect for NULM. Creatinine displayed significant positive interferences with NULM starting at the lowest TG concentration (P = 0.028). There was no clinically relevant interference in cardiac markers for both lipemia types. Conclusions: Significant differences were scrutinized in interference patterns of lipemia types, emphasizing the need for careful consideration of lipemia interferences in clinical laboratories. It is crucial to note that lipid emulsions inadequately replicate lipemic samples.

Impact of sex used for assignment of reference intervals in a population of patients taking gender-affirming hormones.

Background: Gender-affirming hormone therapy with either estradiol or testosterone for transgender persons can significantly impact chemistry and hematology laboratory tests. The sex used for assignment of reference intervals (RIs) in the electronic health record (EHR) will influence normal/abnormal flagging of test results. Objective: To analyze common non-hormonal laboratory tests with sex-specific RIs ordered in patients with sexual orientation/gender identify (SOGI) field differences (one or more differences between legal sex, sex assigned at birth, and gender identity) in the EHR at an academic medical center in midwestern United States. Methods: We utilized a previously characterized data set of patients at our institution that included chart review information on gender identity and gender-affirming therapy. We focused on the subset of these patients that had orders for 18 common laboratory tests in calendar year 2021. Results: A total of 1336 patients with SOGI field differences (1218 or 91.2% identifying as gender-expansive; 892 or 66.8% receiving estradiol or testosterone as gender-affirming therapy) had a total of 9374 orders for 18 laboratory tests with sex-specific RIs. Hemoglobin, creatinine, alkaline phosphatase, alanine aminotransferase, aspartate aminotransferase, and high-density lipoprotein were the most frequently ordered tests. For patients taking estradiol, 128 of 970 (13.2%) creatinine and 39 of 193 (20.2%) hemoglobin measurements were within the RI for one sex but not the other. For those taking testosterone, 119 of 531 (22.4%) creatinine and 49 of 120 (40.8%) hemoglobin measurements were within the RI for one sex but not the other. Values above the cisgender female RI but within the cisgender male RI were common for hemoglobin, alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase in patients taking testosterone. Conclusions: Clinicians should be aware of the potential impact of gender-affirming therapy on laboratory tests and what sex/gender is being used in the EHR to assign RIs.

Quality impact on diagnostic blood specimen collection using a new device to relieve venipuncture pain.

A new device called Buzzy(®) has been recently presented that combines a cooling ice pack and a vibrating motor in order to relieve the venipuncture pain. The aim of this study was to evaluate the impact of Buzzy(®) use during diagnostic blood specimen collection by venipuncture for routine immunochemistry tests. Blood was collected from 100 volunteers by a single, expert phlebotomist. A vein was located on the left forearm without applying tourniquet, in order to prevent any interference from venous stasis, and blood samples were collected using a 20-G straight needle directly into 5 mL vacuum tubes with clot activator and gel separator. In sequence, external cold and vibration by Buzzy(®) was applied on the right forearm-5 cm above the chosen puncture site-for 1 min before venipuncture and continued until the end of the same procedure already done in the left forearm. The panel of tests included the following: glucose, total cholesterol, HDL-cholesterol, triglycerides, total protein, albumin, c-reactive protein, urea, creatinine, uric acid, alkaline phosphatase, amylase, AST, ALT, g-glutamyltransferase, lactate dehydrogenase, creatine kinase, total bilirubin, phosphorus, calcium, magnesium, iron, sodium, potassium, chloride, lipase, cortisol, insulin, thyroid-stimulating hormone, total triiodothyronine, free triiodothyronine, total thyroxine, free thyroxine and haemolysis index. Clinically significant differences between samples were found only for: total protein, albumin and transferrin. The Buzzy(®) can be used during diagnostic blood specimens collection by venipuncture for the majority of the routine immunochemistry tests. We only suggest avoiding this device during blood collection when protein, albumin and transferrin determinations should be performed.

A bicentric cohort study comparing umbilical cord and neonatal blood samples for chemistry tests at birth.

OBJECTIVES: To compare umbilical cord and neonatal blood for chemistry tests upon admission to the neonatal intensive care unit (NICU). METHODS: We designed a prospective, bicentric cohort study enrolling newborns (n = 71) with a planned admission to the NICU. Paired samples of umbilical cord and infant's blood were collected, analyzed, and compared. An intraclass correlation coefficient (ICC) was calculated for a repeatability analysis, and a Bland-Altman analysis was performed to assess the agreement between the 2 methods of sampling. The multivariable coefficient of determination (R2) was reported to quantify the degree of correlation between the methods of measurement. RESULTS: The degree of agreement between the 2 sampling methods for chemistry tests was fair to good for high-sensitivity C-reactive protein (ICC = 0.79 [95% CI, 0.67-0.87]), phosphorus (ICC = 0.83 [95% CI, 0.73-0.90]), and albumin (ICC = 0.76 [95% CI, 0.60-0.86]), while it was good to excellent for γ-glutamyl transpeptidase (ICC = 0.95 [95% CI, 0.88-0.98]) and procalcitonin (ICC = 0.90 [95% CI, 0.76-0.96]). CONCLUSIONS: Umbilical cord blood is a reliable replacement source for multiple chemistry tests at birth. This sampling method has the potential to minimize the risk of transfusion-requiring anemia in newborns and its associated complications. Further studies are warranted to assess the efficacy of this strategy in improving neonatal outcomes.

Is minimising waste volume for drawing blood samples in critically ill patients feasible?

INTRODUCTION: Drawing blood samples through a central venous catheter (CVC) is a customary practice in Intensive Care Units (ICUs). It is indicated to discard a volume of waste blood to avoid interference in the results. AIM: To determine whether a lower discard volume for obtaining blood samples from temporary CVCs placed into the internal jugular, femoral or subclavian vein offers valid results. METHOD: A quasi-experimental prospective cross-sectional study for which sixty-five patients of over 18 years of age in ICUs, who had been fitted with a triple lumen central venous catheter, were recruited over a period of eight months. Two consecutive blood samples were extracted with tubes for biochemistry, coagulation and hemogram from each patient from the distal lumen. The first sample was obtained with a discarded waste of 1.5 ml from a total extracted volume of 10.2 ml, similar to the usual waste in our ambit (10 ml). Subsequently the second sample was obtained. The paired t-test was used to analyse the data. The Bland-Altman plot and intraclass correlation coefficient (ICC) were used to measure the agreement between methods. The reference change value (RCV) was established as the admissible limit of variation between the pairs of samples. RESULTS: A total of 65 sample pairs were drawn (intervention-control). The paired t-test found statistically significant differences with a significance level of α = .05 for chlorine (-.536; .012); prothrombin time (-.092; .019) and prothrombin activity (.284; 1.375).The ICC was greater than .9 in all the variables and the limit determined for the RCV was not surpassed by any value. CONCLUSIONS: The results show the reliability of the blood samples drawn with a discard volume of 1.5 ml.