Point-of-care measurement of clozapine concentration using a finger-stick blood sample

2021 ◽  
pp. 026988112199156
Author(s):  
David Taylor ◽  
Matthew Atkins ◽  
Robert Harland ◽  
Irina Baburina ◽  
James H MacCabe ◽  
...  
Keyword(s):  
Blood Sample ◽  
Point Of Care ◽  
Venous Blood ◽  
Laboratory Method ◽  
Capillary Blood ◽  
Strong Positive Correlation ◽  
Blood Samples ◽  
Clozapine Concentration ◽  
Capillary Sample ◽  
Finger Stick

Background: The use of clozapine demands regular monitoring of clozapine plasma concentrations and of white blood cell parameters. The delay between sending blood samples for analysis and receiving the results hinders clinical care. Point-of-care testing (POCT) can provide drug assay results within a few minutes. Aim: This study aimed to investigate the utility of a novel point-of-care device that can measure clozapine concentrations using capillary blood samples collected via a finger stick. Method: During a five-week period starting in June 2019 eligible patients were asked to provide a finger-stick capillary sample in addition to their usual venous blood sample. Samples were analysed by the novel point-of-care device and by the standard laboratory method. Capillary blood samples were tested by the MyCare™ Insite POCT analyser, and a quantitative measurement of clozapine concentration was provided within six minutes. Results: A total of 309 patients agreed to measurements by the two methods. Analysis revealed clozapine concentrations in venous blood as determined by the laboratory method ranged from 20 to 1310 ng/mL and by POCT from 7 to 1425 ng/mL. There was a strong positive correlation ( R = 0.89) between the results from the venous and the capillary sample methods. The slope of the association between standard assay and MyCare™ Insite was 1.0 with an intercept of –21 ng/mL, indicating minimal bias. Conclusion: Clozapine concentrations can be accurately measured at the point of care using capillary blood samples collected via a finger stick. This approach may be more acceptable than venous sampling to patients and, with almost instant results available, more useful to clinicians.

Measurement accuracy of two professional-use systems for point-of-care testing of blood glucose

2020 ◽  
Vol 58 (3) ◽  
pp. 445-455
Author(s):  
Annette Baumstark ◽  
Nina Jendrike ◽  
Ulrike Kamecke ◽  
Christina Liebing ◽  
Stefan Pleus ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Point Of Care ◽  
Venous Blood ◽  
Laboratory Method ◽  
Sample Type ◽  
Point Of Care Testing ◽  
Blood Samples ◽  
Testing Procedures ◽  
Grid Analysis ◽  
Error Grid

AbstractBackgroundThe professional-use systems HemoCue® Glucose 201+ (HC201+) and HemoCue® Glucose 201 RT (HC201RT) are widely used for point-of-care testing (POCT) of blood glucose (BG). HC201RT utilizes unit-use microcuvettes which can be stored at room temperature, whereas HC201+ microcuvettes have to be stored at <8 °C. In this study, system accuracy of HC201+ and HC201RT was evaluated using capillary and venous blood samples.MethodsFor each system, two reagent system lots were evaluated within a period of 2 years based on testing procedures of ISO 15197:2013, a standard applicable for self-monitoring of blood glucose (SMBG) systems. For each reagent system lot, the investigation was performed by using 100 capillary and 95 to 99 venous blood samples. Comparison measurements were performed with a hexokinase laboratory method. Accuracy criteria of ISO 15197:2013 and POCT12-A3 were applied. In addition, bias was analyzed according to Bland and Altman, and error grid analysis was performed.ResultsWhen measuring capillary samples, both systems fulfilled accuracy requirements of ISO 15197:2013 and POCT12-A3 with the investigated reagent system lots. When measuring venous samples, only HC201+ fulfilled these requirements. Bias between HC201+ and reference measurements was more consistent over venous and capillary samples and microcuvette lots than for HC201RT. Error grid analysis showed that clinical actions might have been different depending on which system was used.ConclusionsIn this study, HC201+ showed a high level of accuracy irrespective of the sample type (capillary or venous). In contrast, HC201RT measurement results were markedly affected by the type of sample.

scholarly journals Analytical performance of lateral flow immunoassay for SARS-CoV-2 exposure screening on venous and capillary blood samples

2020 ◽  
Author(s):  
Margaret A Black ◽  
Guomiao Shen ◽  
Xiaojun Feng ◽  
Wilfredo Garcia Beltran ◽  
Yang Feng ◽  
...  
Keyword(s):  
Whole Blood ◽  
Colloidal Gold ◽  
Venous Blood ◽  
Capillary Blood ◽  
Lateral Flow ◽  
Antibody Detection ◽  
Lateral Flow Immunoassay ◽  
Blood Samples ◽  
Significant Difference ◽  
Finger Stick

Objectives: Numerous serologic immunoassays have been launched to detect antibodies to SARS-CoV-2, including rapid tests. Here, we validate use of a lateral flow immunoassay (LFI) intended for rapid screening and qualitative detection of anti-SARS-CoV-2 IgM and IgG in serum, plasma, and whole blood, and compare results with ELISA. We also seek to establish the value of LFI testing on blood obtained from a capillary blood sample. Methods: Samples collected by venous blood draw and capillary finger stick were obtained from patients with SARS-CoV-2 detected by RT-qPCR and control patients negative for SARS-CoV-2. Samples were tested with the 2019-nCoV IgG/IgM Detection Kit (Colloidal Gold) lateral flow immunoassay, and antibody calls were compared with results obtained by ELISA. Results: The Biolidics LFI kit shows clinical sensitivity of 92% at 7 days after PCR diagnosis of SARS-CoV-2 on venous blood. Test specificity was 92% for IgM and 100% for IgG. There was no significant difference in detecting IgM and IgG with Biolidics LFI and ELISA at D0 and D7 (p=1.00), except for detection of IgM at D7 (p=0.04). Finger stick whole blood of SARS-CoV-2 patients showed 93% sensitivity for antibody detection. Conclusions: Clinical performance of Biolidics 2019-nCoV IgG/IgM Detection Kit (Colloidal Gold) is comparable to ELISA and showed consistent results across different sample types. Furthermore, we show that capillary blood obtained by finger stick shows similar sensitivity for detecting anti-SARS-CoV-2 IgM and IgG antibodies as venous blood samples. This provides an opportunity for decentralized rapid testing in the community and may allow point-of-care and longitudinal self-testing for the presence of anti-SARS-CoV-2 antibodies.

scholarly journals A Comparison of Capillary and Venous Blood Haematocrits of Pregnant Women in Nigeria: The Impact on Diagnosis and Prevalence of Anaemia in Pregnancy

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Cyril Chukwudi Dim ◽  
Emmanuel Onyebuchi Ugwu ◽  
Ugochukwu Bond Anyaehie ◽  
Kingsley Chukwu Obioha
Keyword(s):  
Pregnant Women ◽  
Venous Blood ◽  
Antenatal Clinic ◽  
Capillary Blood ◽  
Strong Positive Correlation ◽  
Blood Samples ◽  
Nigeria Teaching Hospital ◽  
Anaemia In Pregnancy ◽  
The Impact ◽  
In Pregnancy

Background. Volume of red cells in capillary blood varies from that of venous blood. The magnitude of this variation as well as its impact on the diagnosis of anaemia in pregnancy needs to be studied. This study demonstrates the disparity between capillary and venous PCV in pregnancy.Objectives. To determine whether capillary blood PCV (cPCV) differed from venous blood PCV (vPCV) of normal pregnant women in Enugu, Nigeria, and its effect on diagnosis and prevalence of anaemia.Methods. PCV was estimated using pairs of venous and capillary blood samples from 200 consecutive pregnant women at the Antenatal Clinic of University of Nigeria Teaching Hospital, Enugu, Nigeria.Results. Participants’ cPCV(median=34.0%,IQR=31.0–35.8)was significantly lower than their vPCV(median=34.0%,IQR=32.0–37.0)(Z=-6.85,P<0.001). However, women’s cPCV had strong positive correlation with their vPCV (r=0.883,P<0.001). The prevalence of anaemia among participants using capillary and venous blood was 33.5% (67/200) and 28.0% (56/200), respectively (O.R=1.3(CI 95%: 0.85, 1.98),  P=0.233).Conclusions. Capillary blood PCV was lower than vPCV among pregnant women in Enugu, Nigeria. Nevertheless, the prevalence of anaemia derived from cPCV did not differ significantly from that of vPCV.

A Comparison of Venous versus Capillary Blood Samples when Measuring Blood Glucose Using a Point-of-Care, Capillary-Based Glucometer

2019 ◽  
Vol 34 (05) ◽  
pp. 506-509
Author(s):  
Jessica Topping ◽  
Matthew Reardon ◽  
Jake Coleman ◽  
Brian Hunter ◽  
Haruka Shojima-Perera ◽  
...  
Keyword(s):  
Blood Glucose ◽  
Point Of Care ◽  
Research Question ◽  
Venous Blood ◽  
Hospital Setting ◽  
Capillary Blood ◽  
Needle Stick Injury ◽  
Blood Samples ◽  
Significant Difference ◽  
Venous Sample

AbstractBackground:Blood glucose level (BGL) is routinely assessed by paramedics in the out-of-hospital setting. Most commonly, BGL is measured using a blood sample of capillary origin analyzed by a hand-held, point-of-care glucometer. In some clinical circumstances, the capillary sample may be replaced by blood of venous origin. Given most point-of-care glucometers are engineered to analyze capillary blood samples, the use of venous blood instead of capillary may lead to inaccurate or misleading measurements.Hypothesis/Problem:The aim of this prospective study was to compare mean difference in BGL between venous and capillary blood from healthy volunteers when measured using a capillary-based, hand-held, point-of-care glucometer.Methods:Using a prospective observational comparison design, 36 healthy participants provided paired samples of blood, one venous and the other capillary, taken near simultaneously. The BGL values were similar between the two groups. The capillary group had a range of 4.3mmol/l, with the lowest value being 4.4mmol/l and 8.7mmol/l the highest. The venous group had a range of 2.7mmol/l, with the lowest value being 4.1mmol/l and 7.0mmol/l the highest.For the primary research question, the mean BGL for the venous sample group was 5.3mmol/l (SD = 0.6), compared to 5.6mmol/l (SD = 0.8) for the capillary group. This represented a statistically significant difference of 0.3mmol/l (P = .04), but it did not reach the a priori established point of clinical significance (1.0mmol/l). Pearson’s correlation coefficient for capillary versus venous indicated moderate correlation (r = 0.42).Conclusion:In healthy, non-fasted people in a non-clinical setting, a statistically significant, but not clinically significant, difference was found between venous- and capillary-derived BGL when measured using a point-of-care, capillary-based glucometer. Correlation between the two was moderate. In this context, using venous samples in a capillary-based glucometer is reasonable providing the venous sample can be gathered without exposure of the clinician to risk of needle-stick injury. In clinical settings where physiological derangement or acute illness is present, capillary sampling would remain the optimal approach.

scholarly journals Using a fingerstick test for haematological monitoring in patients treated with clozapine

2021 ◽  
Vol 11 ◽  
pp. 204512532110008
Author(s):  
Matthew Atkins ◽  
Philip McGuire ◽  
Bhirundra Balgobin ◽  
Pravinkumar Patel ◽  
David Taylor
Keyword(s):  
Regression Analysis ◽  
Confidence Interval ◽  
Blood Cell ◽  
Point Of Care ◽  
Venous Blood ◽  
Capillary Blood ◽  
Test Results ◽  
Capillary Method ◽  
Capillary Sample ◽  
Venous Sample

Background Treatment with clozapine requires regular blood monitoring in order to minimise the risk of agranulocytosis. The demands on patients and clinicians associated with monitoring may be reduced by using point-of-care, as opposed to lab-based assessments. We assessed the utility of a device that can measure white blood cell (WBC) and neutrophil counts by capillary fingerstick blood. Method The performance of a small, portable device (HemoCue® WBC DIFF System) was compared with that of a widely used laboratory analyser (ADVIA® 2120i) for measuring WBC and neutrophil counts. Patients with schizophrenia who were being treated with clozapine ( n = 201) provided a fingerstick capillary sample and a venous sample for the respective assays. Results WBC counts and neutrophil counts from venous blood as determined by ADVIA 2120i, ranged from 3.0 × 109/l to 19.5 × 109/l, and 1.2 × 109/l to 15.9 × 109/l, respectively. There was a strong correlation between the results from venous and the capillary sample methods (WBC: R = 0.89, neutrophil: R = 0.92). By Passing–Bablok regression analysis, the slope of the association between ADVIA® 2120i and HemoCue WBC DIFF for WBC was 1.0 [95% confidence interval (CI) 0.944–1.086], with intercept at −0.9 (95% CI −1.43 to −0.45). For neutrophils, the slope was 0.870 (95% CI 0.817–0.923), with intercept at −0.19 (95% CI −0.43 to 0.02). Overall, mean biases of −0.95 × 109/l for WBC, and −0.91 × 109/l for neutrophils were observed for the capillary blood method compared with the venous blood method. Below the clinical cutoff intervals for clozapine monitoring WBC (<3.5 × 109/l) and neutrophils (<1.5 × 109/l) these biases were −1.1 × 109/l for WBC, and −0.25 × 109/l for neutrophils. Conclusion Results from the capillary blood HemoCue WBC DIFF analyser compared well with the venous blood ADVIA 2120i analyser for determining WBC and neutrophil counts. There was a slight overall bias, with the capillary method reporting lower values for both measures. Fingerstick point-of-care analysis is suitable for monitoring blood counts in patients on clozapine, although confirmatory standard venous testing is recommended for test results falling below accepted thresholds.

Potassium but Not Lactate Dehydrogenase Elevation Due To In Vitro Hemolysis Is Higher in Capillary Than in Venous Blood Samples

2012 ◽  
Vol 136 (10) ◽  
pp. 1262-1265 ◽  
Author(s):  
Marlies Oostendorp ◽  
Wouter W. van Solinge ◽  
Hans Kemperman
Keyword(s):  
Lactate Dehydrogenase ◽  
Point Of Care ◽  
Venous Blood ◽  
Capillary Blood ◽  
Venous Sampling ◽  
H Index ◽  
Blood Samples ◽  
Capillary Sampling ◽  
Capillary Blood Sampling

Context.—Elevated potassium concentrations due to in vitro hemolysis can lead to errors in diagnoses and treatment. Recently, we observed that potassium elevation in capillary samples appeared higher than expected, based on hemolytic index (H-index). Objective.—To investigate the relation between potassium increase and H-index for capillary samples. As a control, the same analysis was performed for lactate dehydrogenase (LDH). Design.—Potassium results of 332 760 venous and 2620 capillary samples were selected. For LDH, 135 974 venous and 999 capillary samples were included. Venous and capillary samples were differentiated by using patient age, as we perform mostly capillary blood sampling in children and venous sampling in adults. Results were obtained with Beckman-Coulter DxC800 analyzers. Results.—The increase in potassium with increasing H-index was considerably higher for capillary samples than venous samples. Linear regression revealed a potassium increase of 0.38 mEq/L per increment in H-index for capillary samples, whereas a 0.17 mEq/L increase was found for venous samples. For LDH, no differences were found between venous and capillary samples. Conclusions.—At identical H-index, capillary samples showed higher potassium elevations than venous samples. A possible explanation is that capillary sampling causes increased leakage of ions, such as potassium, from erythrocytes, compared with proteins such as hemoglobin and LDH. These results are especially important considering the increasing use of whole blood point-of-care analyzers, where the H-index is often not determined. Potassium results should therefore be interpreted with caution to avoid severe misdiagnosis of hypokalemia and hyperkalemia.

scholarly journals Comparison of capillary, venous and buffy coat blood samples in detecting Plasmodium species among malaria suspected patients attending at Hamusite health center. A cross-sectional study

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Getu Abeje ◽  
Woyneshet Gelaye ◽  
Getaneh Alemu
Keyword(s):  
Health Center ◽  
Detection Rate ◽  
Venous Blood ◽  
Cross Sectional Study ◽  
Buffy Coat ◽  
Blood Film ◽  
Capillary Blood ◽  
Sectional Study ◽  
Cross Sectional ◽  
Blood Samples

Abstract Background Both capillary and venous blood samples have been interchangeably used for the diagnosis of malaria in Ethiopia. However, Plasmodium parasites are thought to be more concentrated in capillary than in venous blood. Hence, selecting a sample source where parasites are more concentrated is indispensable approach in order to maximize the accuracy of blood film microscopy. Therefore, the present study aimed to compare the detection rate and the parasitemia level of Plasmodium species from conventional capillary and venous blood films, and buffy coat preparations. Methods A facility based cross-sectional study was conducted from Feburary to March 2020 among 210 febrile patients attending Hamusite health center, northwest Ethiopia. Capillary and venous blood samples were collected and buffy coat was prepared from each sample. Thin and thick blood films were prepared, stained, and examined microscopically following standard protocol. Data were analysed using Statistical Package for Social Sciences Software version 20 and Med-Calc software version 19.3. Results Capillary blood buffy coat (61/210, 29.0%) had significantly higher detection rate as compared to capillary (48/210, 22.9%) and venous (42/210, 20.0%) blood films (p < 0.001). However, no significant difference was observed between capillary and venous blood films (p = 0.070) in detecting Plasmodium species. The highest and the lowest mean asexual stage parasite counts were found in capillary blood buffy coat (4692.88) and venous blood (631.43) films, respectively showing significant variations (p < 0.001). Mean gametocyte count was also highest in capillary blood buffy coat (3958.44). As compared to capillary blood buffy coat, the sensitivity of venous blood buffy coat, capillary blood film and venous blood film were 73.8, 78.7, 68.9%, respectively. Conclusion Capillary blood buffy coat samples showed the highest sensitivity in detecting and quantitating malaria parasites that its use should be promoted in clinical settings. However, conventional capillary and venous blood films could be used interchangeably.

Effects of Different Methods Used to Take Blood Samples on Blood Glucose Measurements

2021 ◽  
pp. 105477382110247
Author(s):  
Eda Ergin ◽  
Ayten Zaybak
Keyword(s):  
Blood Glucose ◽  
Glucose Tolerance Test ◽  
Venous Blood ◽  
Tolerance Test ◽  
Capillary Blood ◽  
Oral Glucose ◽  
Blood Samples ◽  
Significant Difference ◽  
Measurement Results ◽  
Quasi Experimental

The purpose of this study is to compare whether or not there is a difference between venous and capillary blood samples in blood glucose measurements and investigate the effects of different aseptic methods used in skin cleaning before collecting blood samples on measurement results. This quasi-experimental study was conducted with 109 patients. The capillary first and second blood drop values taken from the patients after fasting and at 2 hours following 75 g oral glucose tolerance test (OGTT) and capillary and venous blood glucose values were compared. There was no significant difference between the median venous blood glucose value and the capillary second blood drop value taken after wiping the finger with alcohol. There was no significant difference between the first and second blood drop values of capillary blood glucose 2 hours after OGTT.

scholarly journals Blood Glucose Assay Using Dextrostix and a Reflectance Meter

1972 ◽  
Vol 9 (1-6) ◽  
pp. 91-94 ◽  
Author(s):  
I. W. Percy-Robb ◽  
R. S. McMaster ◽  
A. D. B. Harrower ◽  
L. J. P. Duncan
Keyword(s):  
Blood Glucose ◽  
Venous Blood ◽  
Reference Method ◽  
Capillary Blood ◽  
Blood Samples ◽  
Laboratory Staff ◽  
Glucose Assay ◽  
Reflectance Meter ◽  
High Degree ◽  
Blood Glucose Concentrations

The ‘Dextrostix’-reflectance meter system for blood glucose analysis has been evaluated using a blood glucose reference method. A high degree of concordance between the two methods was obtained when analyses were performed by skilled laboratory staff on venous blood samples containing fluoride, with a 75 s contact time. Skilled laboratory staff performed significantly better than unskilled staff. Capillary blood glucose concentrations correlated poorly with concentrations in venous blood samples taken at the same time as the capillary blood.

Comparative study of i-SENS glucometers in neonates using capillary blood samples

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ha Nui Kim ◽  
Soo-Young Yoon
Keyword(s):  
Reference Values ◽  
Point Of Care ◽  
Evaluation Process ◽  
Capillary Blood ◽  
Performance Criteria ◽  
Accuracy Evaluation ◽  
Blood Samples ◽  
Average Reference ◽  
Error Grid ◽  
Accuracy Performance

Abstract Objectives The accuracy of point-of-care blood glucometers in the detection and evaluation of neonatal hypoglycemia is a concern. This study compared the performance of three i-SENS glucometers with that of the YSI 2300 STAT Plus Analyzer, which was used as a reference. Methods The leftover neonatal capillary blood samples of 319 patients were used in this study. The evaluation process and accuracy performance criteria were based on the International Organization for Standardization 15197:2013 guidelines. The evaluation involved three i-SENS glucometers (BAROzen H Expert plus, CareSens PRO, and CareSens H Beat) and the ACCU-CHEK® Inform II glucometer. Results The accuracy evaluation yielded acceptable results as follows: a) 100 and 100% for BAROzen H Expert plus; 99.8 and 100% for CareSens PRO; 98.7%, and 97.2% for CareSens H Beat glucometers were within the range of ±0.8 mmol/L (15 mg/dL) and ±15% of the average reference values at glucose concentrations <5.55 mmol/L (100 mg/dL) and ≥5.55 mmol/L (100 mg/dL), respectively, and b) all estimated glucose values (100%) were within the zones A and B of Consensus Error Grid for all three i-SENS glucometers. There was good correlation between the glucose values estimated by the glucometers and the reference values (R>0.990). Conclusions This study demonstrated that i-SENS glucometers exhibit acceptable performance and can be used as effective point-of-care devices in neonates.

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