Blood Draw Barriers for Treatment with Clozapine and Development of a Point-of-Care Monitoring Device

Abstract Background Between December 2018 and January of 2019, we evaluated the accuracy of the point-of-care Hepatitis C (HCV) antibody test (POC; OraQuick HCV) used at a community-based needle and syringe exchange program serving persons who inject drugs in Tallinn, Estonia. Methods We compared the results of screening for HCV antibodies by OraQuick (oral swab) and enzyme immunoassay (EIA; blood draw) and assessed test results implications in a high prevalence setting. Findings Of the 100 participants, 88 (88%) had reactive POC test results, and 93 were HCV antibody positive on EIA testing. Sensitivity, specificity and negative predictive value (NPV) for the POC assay with EIA as the relevant reference test were as follows: 94.6% (95% CI 90.0–99.2%), 100% and 58.3% (95% CI 30.4–86.2%). Of the 12 testing, HCV-negative with the POC only 7 (58.3%) were true negatives. Conclusions Oral swab rapid testing HCV screening in this nonclinical setting was sensitive and specific but had unacceptably low NPV. In high prevalence settings, POC tests with high sensitivity and that directly measure HCV RNA may be warranted.

Download Full-text

The Use of Microfluidic Technology for Cancer Applications and Liquid Biopsy

Micromachines ◽

10.3390/mi9080397 ◽

2018 ◽

Vol 9 (8) ◽

pp. 397 ◽

Cited By ~ 15

Author(s):

Arutha Kulasinghe ◽

Hanjie Wu ◽

Chamindie Punyadeera ◽

Majid Warkiani

Keyword(s):

Tumor Markers ◽

Liquid Biopsy ◽

Point Of Care ◽

High Sensitivity ◽

Circulating Tumor Dna ◽

Diagnostic Tools ◽

Tumor Biomarkers ◽

Blood Draw ◽

Tumor Biopsy ◽

Microfluidic Technology

There is growing awareness for the need of early diagnostic tools to aid in point-of-care testing in cancer. Tumor biopsy remains the conventional means in which to sample a tumor and often presents with challenges and associated risks. Therefore, alternative sources of tumor biomarkers is needed. Liquid biopsy has gained attention due to its non-invasive sampling of tumor tissue and ability to serially assess disease via a simple blood draw over the course of treatment. Among the leading technologies developing liquid biopsy solutions, microfluidics has recently come to the fore. Microfluidic platforms offer cellular separation and analysis platforms that allow for high throughout, high sensitivity and specificity, low sample volumes and reagent costs and precise liquid controlling capabilities. These characteristics make microfluidic technology a promising tool in separating and analyzing circulating tumor biomarkers for diagnosis, prognosis and monitoring. In this review, the characteristics of three kinds of circulating tumor markers will be described in the context of cancer, circulating tumor cells (CTCs), exosomes, and circulating tumor DNA (ctDNA). The review will focus on how the introduction of microfluidic technologies has improved the separation and analysis of these circulating tumor markers.

Download Full-text

Use of Venipuncture Blood Sample for INR Testing on a Point of Care Machine.

Blood ◽

10.1182/blood.v106.11.4159.4159 ◽

2005 ◽

Vol 106 (11) ◽

pp. 4159-4159

Author(s):

Mandeep S. Dhami ◽

Anca Bulgaru ◽

K. Jagathambal ◽

Dinesh Kapur ◽

Francine Norris ◽

...

Keyword(s):

Regression Analysis ◽

Blood Sample ◽

Warfarin Therapy ◽

Point Of Care ◽

Test Strip ◽

International Normalized Ratio ◽

Blood Draw ◽

Number Of Patients ◽

Obtain Blood Sample ◽

Oncology Practice

Abstract Point of care (POC) testing of International Normalized Ratio (INR) for monitoring warfarin therapy is rapidly becoming procedure of choice for patients requiring long term oral anticoagulation. This method allows for fingerstick blood sample to be used for INR testing at the point of service with immediate dose modification as needed. Most patients prefer a fingerstick method for blood draw to venipuncture. It is not known if venipuncture blood sample can be used for testing on POC machines. A significant number of patients in an oncology practice need additional laboratory testing on the same day as INR testing. These patients therefore get a fingerstick for POC INR testing and a venipuncture for other tests. We compared results of INR from venipuncture sample run on a POC machine (CoaguChek monitor) using CoaguChek test strips (ISI-2.0) with the INR performed on MDA analyzer (ISI-2.0). Blood samples from 24 patients on warfarin therapy were drawn from antecubital vein by a clean stick in a 10 cc plastic syringe. A drop of blood was immediately placed on the CoaguCheck test strip. Next the same blood sample was used to fill a 3.2% sodium citrate tube for testing on MDA analyzer. Results were analyzed using regression analysis; the correlation coefficient (r), slope and intercept were determined and following graph of the regression analysis was generated (see figure 1). Conclusions: These results show a good correlation (r-value> 0.9) between the results of INR obtained on CoaguChek POC machine and the MDA analyzer using venipuncture blood sample. The preferred method to obtain blood sample for POC INR monitoring must remain fingerstick sample as per manufacturer’s recommendations. However, for those patients who need more than one blood sample done on the same day, a venipuncture sample as described above gives acceptable results when tested on CoaguCheck machine. Figure Figure

Download Full-text

Quality Assurance At the Point of Care: PT/INR: What Is the Gold Standard for Patient Treatment?.

Blood ◽

10.1182/blood.v120.21.3170.3170 ◽

2012 ◽

Vol 120 (21) ◽

pp. 3170-3170

Author(s):

Michael Plietz ◽

Aaron Leifer ◽

Amy S Fox ◽

Khrishan Naraine ◽

Vilma Padilla ◽

...

Keyword(s):

Therapeutic Range ◽

Gold Standard ◽

Conflicts Of Interest ◽

Point Of Care ◽

Patient Treatment ◽

P Value ◽

Optimal Conditions ◽

Sample Collection ◽

Blood Draw ◽

Coaguchek Xs

Abstract Abstract 3170 Background: The Prothrombin time (PT) can be performed in laboratories by instruments such as BCS (Siemens), and at the Point of Care using devices such as the Protime 3 (ITC) and the Coaguchek XS (Roche). Laboratory based instruments such as the BCS have been regarded as the Gold Standard for PT/INR assuming results can be obtained in under 24 hours from blood drawn in an uncentrifuged sample. A previous study performed in the Netherlands recommends that INR testing be completed within 6 hours of blood draw. This recommendation has not been universally adopted. In order to assess this effect, a study comparing the laboratory instrument (BCS) to POC instruments was performed while simultaneously comparing lab based results at or greater than 6 hours. Methods: The INR values of the BCS in two separate laboratories, Coaguchek XS, and Protime 3 were compared to each other. The INR values and turnaround times for each were recorded. The results were compared using paired observation T-tests and regression analysis including all data and within sub-therapeutic (<2), therapeutic (2.0–3.0), and supratherapeutic range (>3.0). Additionally, point of care results were compared to BCS test results before and after 6 hours. Results: 60 patients had 3 INR test methods performed. All samples were tested in two different reference laboratories, both using BCS testing method. Reference lab A performed the tests under optimal conditions including a turnaround times of less than 2 hours, while Reference lab B performed the tests under usual workflow conditions. While the total Protime 3 results were significantly different from Reference lab A, the Coaguchek XS results were not. In the therapeutic range, the Coaguchek XS and Reference lab B had significant correlation (r = .556 and .634 respectively) to reference lab A while the Protime 3 did not (r = .281). Reference lab B results were significantly different from Reference lab A when testing was performed after 6 hours (P-value = .0252), but had similar results to Reference lab A when performed within 6 hours (P-value = .402). The Coaguchek XS showed no significant differences when compared to Reference lab A results (p-value = .1262). Another indicator of lack of concordance between Reference lab A and B, when testing is performed greater than 6 hours, was the change in directionality of the bias (p-value = .0396). Additionally, Protime 3 results in the therapeutic range correlated significantly better with Reference lab B results when they were resulted within 6 hours (r= .191 and r= .782). Conclusions: Based on these findings, the BCS method appears to lose reliability when the test is performed on uncentrifuged blood greater than 6 hours after blood draw. Interestingly, the Coaguchek XS correlated best with Reference lab A, BCS testing under optimal conditions. The Protime 3, on the other hand, was less well correlated with Reference lab A. The change in directionality of the bias also suggests that the BCS results were flawed when testing was performed after 6 hours. Although additional preanalytic factors (i.e. temperature) may have had an effect on these results, these data suggest that laboratory based INR testing should be performed within six hours of sample collection. Disclosures: No relevant conflicts of interest to declare.

Download Full-text

MP14: Community paramedic point of care blood analysis: validity and usability testing of two commercially available devices

CJEM ◽

10.1017/cem.2018.168 ◽

2018 ◽

Vol 20 (S1) ◽

pp. S45-S45

Author(s):

I. E. Blanchard ◽

R. Kozicky ◽

D. Dalgarno ◽

S. Goulder ◽

T. Williamson ◽

...

Keyword(s):

Patient Care ◽

Point Of Care ◽

A Priori ◽

Critical Value ◽

Laboratory Analysis ◽

Blood Analysis ◽

Blood Draw ◽

Calls For Service ◽

Significant Difference ◽

The Difference

Introduction: Community Paramedics (CPs) require access to timely blood analysis in the field to guide treatment and transport decisions. Point of care testing (POCT), as opposed to traditional laboratory analysis, may offer a solution, but limited research exists on CP POCT. The objective of this study is to compare the validity of two POCT devices (Abbott i-STAT® and Alere epoc®) and their use by CPs in the community. Methods: In a CP programme responding to 6,000 annual patient care events, a split sample validation of POCT against traditional laboratory analysis for seven analytes (sodium, potassium, chloride, creatinine, hemoglobin, hematocrit, and glucose) was conducted on a consecutive sample of patients. The difference of proportion of discrepant results between POCT and laboratory was compared using a two sample proportion test. Usability was analysed by survey of CP experience, an expert heuristic evaluation of devices, a review of device-logged errors, coded observations of POCT use during quality control testing, and a linear mixed effects model of Systems Usability Scale (SUS) adjusted for CP clinical and POCT experience. Results: Of 1,649 CP calls for service screened for enrollment, 174 had a blood draw, with 108 patient care encounters (62.1%) enrolled from 73 participants. Participants had a mean age of 58.7 years (SD16.3); 49% were female. In 4 of 646 (0.6%) individual comparisons, POCT reported a critical value that the laboratory did not; with no statistically significant difference in the number of discrepant critical values reported with epoc® compared to i-STAT®. There were no instances of the laboratory reporting a critical value when POCT did not. In 88 of 1,046 (8.4%) individual comparisons, the a priori defined acceptable difference between POCT and the laboratory was exceeded; occurring more often in epoc® (10.7%;95%CI:8.1%,13.3%) compared to i-STAT® (6.1%;95%CI:4.1%,8.2%)(p=0.007). Eighteen of 19 CP surveys were returned, with 11/18 (61.1%) preferring i-STAT® over epoc®. The i-STAT® had a higher mean SUS score (higher usability) compared to the epoc® (84.0/100 vs. 59.6/100; p=0.011). Fewer field blood analysis device-logged errors occurred in i-STAT® (7.8%;95%CI:2.9%,12.7%) compared to epoc® (15.5%;95%CI:9.3%,21.7%) although not statistically significant (p=0.063). Conclusion: CP programs can expect valid results from POCT. Usability assessment suggests a preference for i-STAT.

Download Full-text

Bolstering Community Cooperation in Ebola Resurgence Protocols: Combining Field Blood Draw and Point-of-Care Diagnosis

PLoS Medicine ◽

10.1371/journal.pmed.1002227 ◽

2017 ◽

Vol 14 (1) ◽

pp. e1002227 ◽

Cited By ~ 6

Author(s):

Mosoka P. Fallah ◽

Laura A. Skrip ◽

Philomena Raftery ◽

Miata Kullie ◽

Watta Borbor ◽

...

Keyword(s):

Point Of Care ◽

Blood Draw ◽

Community Cooperation

Download Full-text

Evaluation of the TAS Analyzer and the Low-Range Heparin Management Test in Patients Undergoing Extracorporeal Membrane Oxygenation

Clinical Chemistry ◽

10.1093/clinchem/47.5.858 ◽

2001 ◽

Vol 47 (5) ◽

pp. 858-866 ◽

Cited By ~ 12

Author(s):

Theresa M Ambrose ◽

Curtis A Parvin ◽

Eric Mendeloff ◽

Lori Luchtman-Jones

Keyword(s):

Extracorporeal Membrane Oxygenation ◽

Management Strategy ◽

Point Of Care ◽

Point Of Care Testing ◽

Clotting Time ◽

Blood Draw ◽

Membrane Oxygenation ◽

Activated Clotting Time ◽

The Relationship ◽

Heparin Dosage

Abstract Background: The new Low-Range Heparin Management Test (LHMT), a method for point-of-care testing (POCT) of heparinization, has been designed to function at the low to moderate heparin concentrations typically found in patients undergoing extracorporeal membrane oxygenation (ECMO). In this study, the new method is compared with two POCT methods and a laboratory-based anti-Xa assay. Methods: We obtained 760 whole blood samples from 13 patients undergoing ECMO. All samples were tested immediately by the LHMT, the Activated Clotting Time (ACT) test, and its low-range counterpart (ACT-LR). Aliquots from the same blood draw were frozen for later anti-Xa analysis using the Diagnostica Stago method on the Roche Cobas Fara-II. Results: The precision was best for duplicate citrated LHMT samples (CV = 3.1%). LHMT clotting times (overall median, 162 s) were typically shorter than ACT or ACT-LR times (247 and 235 s, respectively). The relationship between the LHMT and the other POCT methods differed significantly from patient to patient (P <0.0001), and a meaningful single relationship between the methods could not be obtained. The overall correlation coefficient between clotting time values and actual heparin concentrations was ≤0.48 for each of the instruments tested, although time plots of each analyzer’s data suggested that they detected heparin dosage changes within single patients. Conclusions: The performance of the LHMT on the TAS Analyzer is equivalent to that of currently commercially available POCT methods. The lack of agreement between absolute clotting time values and heparin concentrations suggests the need for reexamination of current ECMO patient management strategy.

Download Full-text

Evaluation of the REG1 Anticoagulant System Using Thrombelastography and Thrombin Generation Assay.

Blood ◽

10.1182/blood.v110.11.4010.4010 ◽

2007 ◽

Vol 110 (11) ◽

pp. 4010-4010

Author(s):

Kenichi A. Tanaka ◽

Fania Szlam ◽

Christopher P. Rusconi ◽

Jerrold H. Levy

Keyword(s):

Whole Blood ◽

Thrombin Generation ◽

Thrombus Formation ◽

Point Of Care ◽

Phase 1 ◽

Lag Time ◽

Blood Draw ◽

Blood Samples ◽

Thrombin Generation Assay ◽

Anticoagulant System

Abstract Background: The REG1 system (Regado Biosciences, Inc. Durham, NC) is a novel anticoagulant system which comprises RB006 (drug) and RB007 (antidote). The aptamer, RB006 selectively binds to FIXa and blocks factor Xa generation. RB007 is a complementary ligand that selectively binds to RB006, and reverses its anticoagulant effect (1). Phase 1 testing demonstrated a clear pharmacodynamic dose response to RB006 in plasma coagulation assays (1), but further work is needed to understand the pharmacodynamic response to the REG1 system in whole blood assays. Therefore, we evaluated the effects of RB006 and RB007 alone and in combination using activated partial thromboplastin time (APTT), viscoelastic (TEG®, Haemoscope, IL) and thrombin generation assay (Thrombinoscope™, Synapse BV). Methods: After IRB approval, blood samples were collected from 4 consented healthy volunteers into 3.2% citrate tubes. For APTT and TEG testing blood was placed in thirteen 2 ml Eppendorf tubes. Tube one had 20 μl of saline added and served as a control. The remaining 12 tubes were divided into 3 groups. Group1: RB006 (final concentrations 3, 6, 12, 18 and 24 μg/ml); Group 2: RB007 (final concentrations 6, 12, 24, and 48 μg/ml) and Group 3: combination of both agents at a weight:weight ratio 2 to 1 for RB007:RB006 (final concentrations as above). All testing was performed within 3-hour of blood draw. APTT was done using Hemochron Jr® (ITC, NJ) instrument in recalcified whole blood. TEG was peformed in recalcified whole blood, 360 μl activated with 2 nM thrombin. For Thrombinoscope, whole blood was centrifuged at 2000 x g for 15 min to obtain platelet poor plasma (PPP). PPP samples were prepared to contain the same concentrations of RB006, RB007, and combination of both agents as described in whole blood samples. Thrombin generation analyses were performed using microplate format using diluted Actin (Dade Behring, Marburg, Germany) as a trigger (2). Results: RB006 dose dependently increased APTT (Table 1). Increasing concentrations of RB006 progressively prolonged onset, and decreased the rate of thrombus formation on TEG (Figure1A). On Thrombinoscope, RB006 dose dependently delayed lag time and decreased peak thrombin generation (Table 1, Figure1B). All the parameters of aPTT, TEG and thrombin generation returned back to control values when combination of aptamer-anti-aptamer was tested. RB007 alone had no effects on any of the tests performed. Conclusion: Along with conventional point of care APTT testing TEG and Thrombinoscope methodologies can be very useful in monitoring the anticoagulation effects of aptamer, RB006, and its reversal with anti-aptamer, RB007. Effects of Aptamer, RB006, on aPTT and Thrombinoscope lag time/peak thrombin RB006μg/ml APTT sec Lag time min Peak thrombin nM Data shown as mean ± SD 0 (control) 51.3 ± 1.0 10.8 ± 0.3 244 ± 16.2 3 95.3 ± 3.0 14.2 ± 0.9 173 ± 22.9 6 152 ± 10.0 18.8 ± 0.5 145 ± 23.0 12 183 ± 4.3 24.1 ± 1.1 105 ± 11.0 18 238 ± 15.3 26.3 ± 2.3 92.3 ± 7.3 24 257 ± 11.3 31.3 ± 3.8 88.2 ± 8.3 Figure 1 Figure 1.

Download Full-text

Automated end-to-end blood testing at the point-of-care: Integration of robotic phlebotomy with downstream sample processing

TECHNOLOGY ◽

10.1142/s2339547818500048 ◽

2018 ◽

Vol 06 (02) ◽

pp. 59-66 ◽

Cited By ~ 2

Author(s):

M.L. Balter ◽

J.M. Leipheimer ◽

A.I. Chen ◽

A. Shrirao ◽

T.J. Maguire ◽

...

Keyword(s):

Blood Cell ◽

White Blood Cell ◽

Point Of Care ◽

Analytical Techniques ◽

Success Rates ◽

Blood Draw ◽

Blood Testing ◽

Cell Assay ◽

End To End ◽

Accuracy And Repeatability

Diagnostic blood testing is the most commonly performed clinical procedure in the world, and influences the majority of medical decisions made in hospital and laboratory settings. However, manual blood draw success rates are dependent on clinician skill and patient physiology, and results are generated almost exclusively in centralized labs from large-volume samples using labor-intensive analytical techniques. This paper presents a medical device that enables end-to-end blood testing by performing blood draws and providing diagnostic results in a fully automated fashion at the point-of-care. The system couples an image-guided venipuncture robot, developed to address the challenges of routine venous access, with a centrifuge-based blood analyzer to obtain quantitative measurements of hematology. We first demonstrate a white blood cell assay on the analyzer, using a blood mimicking fluid spiked with fluorescent microbeads, where the area of the packed bead layer is correlated with the bead concentration. Next we perform experiments to evaluate the pumping efficiency of the sample handling module. Finally, studies are conducted on the integrated device — from blood draw to analysis — using blood vessel phantoms to assess the accuracy and repeatability of the resulting white blood cell assay.

Download Full-text

Gamma Gap: A Point-of-Care Test That Correlates With Disease Burden and Treatment Response in Multiple Myeloma

JCO Oncology Practice ◽

10.1200/jop.19.00517 ◽

2020 ◽

Vol 16 (8) ◽

pp. e751-e757

Author(s):

Megan M. Dupuis ◽

Barry Paul ◽

Gavin Loitsch ◽

Parker Mathews ◽

Daniel Feinberg ◽

...

Keyword(s):

Multiple Myeloma ◽

Treatment Response ◽

Linear Models ◽

Point Of Care ◽

Retrospective Chart Review ◽

Disease Status ◽

Total Serum Protein ◽

Total Serum ◽

Blood Draw ◽

Point Of Care Test

PURPOSE: We performed a retrospective chart review on 393 patients with multiple myeloma (MM) to determine the utility of the gamma gap (GG). METHODS: We calculated the difference between a patient’s total serum protein and albumin as a point-of-care test for assessing disease status in MM. RESULTS: GG is highly correlated with the level of M-spike, and the change in GG correlates with myeloma treatment response. In addition, fitted linear models were established that allow for the calculation of M-protein level from the GG within hours from blood draw. CONCLUSION: Our study has important implications in the care of MM, particularly in countries/areas with limited resources.

Download Full-text