The applicability of point-of-care testing (POCT) glucometers for monitoring blood glucose concentrations has been demonstrated. However, their use in diagnosing type 2 diabetes is still debated. Therefore, a new statistical procedure for estimating discordance rates (DRs) was applied in comparing a well-established laboratory method (Ebio) with another laboratory method (Cobas Integra 700) and with several POCT glucometers (Accu-Chek, Accutrend, Elite, HemoCue, Omni) in detecting glucose intolerance states. All procedures led to parallel glucose concentration patterns in capillary blood, venous plasma, and venous blood during oral glucose tolerance tests. However, the mean concentrations differed more or less. The Ebio and Integra results agreed within a maximal deviation of 3%. In blood samples, the HemoCue and Accutrend results were closest to the laboratory procedures (Ebio and Integra) and the highest differences were obtained with the Elite. Comparing whole blood values with those obtained in the aqueous blood compartment (Omni), even greater differences were observed. When all procedures were referred to the same glucose standard, the Ebio, Integra, Accutrend, and Omni results remained almost unchanged, whereas the Elite "moved" toward the Ebio results, and the Accu-Chek results toward the Omni results. Thus, traceability to an aqueous standard was observed with the Ebio, Integra, Accutrend, and Elite in all three sample systems. The Accu-Chek was only traceable in the presence of albumin, and HemoCue was not traceable at all. The clinical relevance of the differences observed between Ebio and POCT glucometers was tested by comparing the relative number of discordant classifications. The highest DRs were observed in the fasting state. They were higher in capillary blood than in the other sample systems. The DRs were found higher with POCT glucometers than with the other established laboratory procedure (Integra). Thus, at least in the fasting state, all POCT glucometers were less reliable than the established laboratory procedures and above the chosen criteria of clinical acceptability (DR < or = 5%). After transforming all glucometer results with a regression function (bias correction), the DRs were less than 5% if compared with the Ebio procedure in all sample systems. In conclusion, the WHO recommendation not to use POCT glucometers for diagnosing type 2 diabetes must be supported. However, after proper recalibration, the tested systems were acceptable. Therefore, manufacturers should reconsider their calibration procedure. Those POCT procedures should be preferred that can be referred to aqueous glucose solutions. PMID:12880146
Püntmann, Isabel; Wosniok, Werner; Haeckel, Rainer
Point-of-care testing (POCT) is becoming a major force in the future evolution of healthcare. It has the potential to expand further by increasing the accessibility, speed and accuracy of results. New developments in POCT technology will predictably occur in four areas: scope, connectivity, non-invasiveness and miniaturization. POCT test menus will continue to grow, wireless connectivity with automatic data capture will
Michael Bissell; Fred Sanfilippo
Point-of-care testing (POCT) is a major force in the future evolution of hospital care, with prospects for even greater expansion of accessibility, speed, and also, hopefully, accuracy of results. New developments in POCT technology will predictably occur in three areas: connectivity, test menu expansion, and noninvasiveness. Connectivity for POCT devices has evolved from point-of-service workstations to standardized POCT data transmission protocols to remote roaming wireless connectivity with automatic data capture. POCT test menus will continue to expand, with more coagulation testing, chemistries, and infectious screening, but also on-site drug screening, intraoperative hormone levels, and microchip DNA diagnostics. Noninvasive POCT will expand beyond the GlucoWatch glucose monitor and the Bilichek noninvasive bilirubin monitor to noninvasive CBCs and Pap smears. PMID:11868693
Point-of-care testing (POCT) remains under scrutiny by healthcare professionals because of its ill-tried, young history. POCT methods are being developed by a few major equipment companies based on rapid progress in informatics and nanotechnology. Issues as POCT quality control, comparability with standard laboratory procedures, standardisation, traceability and round robin testing are being left to hospitals. As a result, the clinical and operational benefits of POCT were first evident for patients on the operating table. For the management of cardiovascular surgery patients, POCT technology is an indispensable aid. Improvement of the technology has meant that clinical laboratory pathologists now recognise the need for POCT beyond their high-throughput areas. PMID:16958595
Nydegger, Urs E; Gygax, Erich; Carrel, Thierry
Point-of-care testing (POCT) has revolutionized clinical decision making in the intensive care unit. Much of the credit for successful systems today could not have happened without the vision of the Connectivity Industry Consortium (CIC). The intent of this working group, first convened in 1999, was to ensure that all POCT devices could connect with any data management system, by-passing frustrations and concerns about separate connections, proprietary software, computer modifications, and other barriers to implementation. The CIC believed that the adoption of a common connectivity standard would finally enable hospitals to pursue POCT initiatives without concerns about compatibility of various bedside laboratory devices and hospital data management systems. More than a decade later, some POCT devices are not compliant with the CIC standards, either due to a lack of technological updating or the manufacturer's unwillingness to embrace the fundamental requirements of the CIC standards. Glucose meters, originally connected in the early 1990s, are the most advanced POCT devices, and their relative sophistication is serving as the benchmark for other laboratory instrumentation at the point of care. Through a discussion of the preanalytical, analytical and postanalytical phases of glucose testing, the complexities of POCT will be illustrated, along with factors relating to safety, quality assurance, and patient outcomes. PMID:21407006
The main objective of this Tutorial Review is to approach the modern principles and practices of Analytical Chemistry to Point-of-Care Testing (POCT) systems in order to contribute to improve both the development of new devices and the reliable application of the existing ones. In this article, after contextualization of the topic, POCT systems (POCTs) are fully defined using several approaches. The requirements of a POCT system to be a robust and reliable tool available to patients and medical workers are described as well as their desirable complementary characteristics. In addition, the technical components of POCTs materialized in the implementation of the steps of the analytical processes (sample introduction, sample processing, visual or instrumental detection, and data processing) are outlined. Besides, analytical properties assigned to POCTs and to their quantitative and qualitative results are highlighted. Special emphasis is given to Quality Assurance and Quality Control procedures, which are essential aspects to achieving reliable results. Finally, decision making based on the results obtained with POCTs is discussed as are their benefits and drawbacks. PMID:20689902
Aguilera-Herrador, Eva; Cruz-Vera, Marta; Valcárcel, Miguel
Point-of-care testing (POCT) has a critical niche in rural and remote indigenous Australia where geographic isolation from laboratory services is common, the resultant turnaround of laboratory results is often slow, and the burden of chronic disease is very high. This paper describes a POCT program called Point-of- Care in Aboriginal Hands, which delivers POCT services for chronic disease prevention and
Mark D. S. Shephard; Beryl C. Mazzachi; Anne K. Shephard
Disclosed herein is a fully-integrated, disposable biochip for point-of-care testing of clinically relevant parameters. Specifically, in accordance with an embodiment of the present invention, the biochip is designed for POCT (point-of-care-testing) of an...
C. H. Ahn G. Beaucage J. Nevin J. W. Choi
Background Clinicians and developers identify sensitivity as an important quality in a point-of-care test (POCT) for sexually transmissible infections (STIs). Little information exists regarding what patients want for STI POCTs. Methods A qualitative study, encompassing five focus groups among attendees of STI and adolescent health centres in Baltimore, Maryland, and Cincinnati, Ohio, were conducted between March 2008 and April 2009. Discussion topics included advantages and disadvantages of having a POCT, perceived barriers to using POCTs in the clinic setting and at home, priorities for the development of new POCTs for STIs, and envisioned characteristics of an ideal POCT. All discussions were recorded and transcribed. A qualitative content analysis was performed to examine frequencies or patterns of recurring codes, which were regrouped and indexed to identify salient themes. Results Patients attending STI and adolescent outpatient clinics are in favour of diagnostic tests that are rapid, easy to read and simple to use. Home testing options for POCTs were acceptable and provided better confidentiality, privacy and convenience, but clinic-based POCTs were also acceptable because they offer definitive results and ensure immediate treatment. Barriers to home POCTs centred on cost and the ability to read and perform the test correctly at home. Opinions did not differ by patient ethnicity, except that Hispanic participants questioned the reliability of home test results, wanted high sensitivity and desired bilingual instructions. Conclusions Patients attending STI and adolescent medical centres are in favour of STI POCTs if they are affordable, rapid, easy to read and simple to use.
Rompalo, Anne M.; Hsieh, Yu-Hsiang; Hogan, Terry; Barnes, Mathilda; Jett-Goheen, Mary; Huppert, Jill S.; Gaydos, Charlotte A.
BackgroundPoint-of-care testing (POCT) is clinical laboratory testing conducted close to the site of patient care. POCT has the potential to provide faster test results and therapeutic intervention with improved patient outcomes. However, when over-utilized or used inappropriately POCT results can be misleading and increase healthcare costs.
James H. Nichols; Robert H. Christenson; William Clarke; Ann Gronowski; Catherine A. Hammett-Stabler; Ellis Jacobs; Steve Kazmierczak; Kent Lewandrowski; Christopher Price; David B. Sacks; Robert L. Sautter; Gregg Shipp; Lori Sokoll; Ian D. Watson; William Winter; Marcia L. Zucker
After successful centralization of laboratory analyses since more than 30 years, advances in biosensors, microprocessors, measurement of undiluted whole blood and miniaturization of laboratory analyzers are leading nowadays more and more to a re-decentralization in the laboratory medicine. Point-of-care-testing (POCT), which is defined as any laboratory test performed outside central or decentralized laboratories, is becoming more and more popular. The theoretical advantages of POCT are faster turn-around-times (TAT), more rapid medical decisions, avoidance of sample identification and sample transport problems and the need of only small specimen volumes. These advantages are frequently mentioned, but are not associated with a clear clinical benefit. The disadvantages of POCT such as incorrect handling and/or maintenance of the analyzers by nontrained clinical staff, inadequate or even absent calibrations and/or quality controls, lack of cost-effectiveness because of an increased number of analyzers and more expensive reagents, insufficient documentation and difficult comparability of the obtained POCT-results with routine laboratory results, are strongly evident. According to the authors' opinion the decision for the establishing of POCT has only to be made in a close co-operation between physicians and laboratorians in order to vouch for necessity and high quality of the analyses. Taking the local situation into consideration (24-h-central laboratory, etc.) the spectrum of parameters measured by means of POCT should be rigorously restricted to the vital functions. Such analytes should be: hemoglobin or hematocrit, activated whole blood clotting time, blood gases, sodium, potassium, ionized calcium, glucose, creatinine, ammonia and lactate. PMID:10073241
Müller, M M; Hackl, W; Griesmacher, A
Point-of-care testing (POCT) of infectious bacterial agents offers substantial benefits for disease diagnosis, mainly by shortening the time required to obtain results and by making the test available bedside or at remote care centers. Immunochromatographic lateral flow biosensors offer a low cost, highly sensitive platform for POCT. In this article, we describe the fabrication and testing of a multiplex immuno-disc
Chen-zhong Li; Katherine Vandenberg; Shradha Prabhulkar; Xuena Zhu; Lisa Schneper; Kalai Methee; Charles J. Rosser; Eugenio Almeide
SUMMARY These guidelines provide information on how to develop and manage a point-of-care (POCT) service so that reliable haematology results are produced regardless of where the test is performed. Many of the issues addressed here are relevant to POCT within hospitals or health centres; however, the principles are equally applicable to care in the commu- nity and doctors' offices. Other
C. BRIGGS; J. CARTER; S.-H. LEE; L. SANDHAUS; R. SIMON-LOPEZ; J.-L. VIVES CORRONS
We developed a portable and easy-to-use nucleic acid amplification test (NAT) system for use in point-of-care testing (POCT). The system shows sensitivity that is sufficiently higher than that of the currently available rapid diagnostic kit and is comparable to that of real-time reverse transcription polymerase chain reaction (RT-PCR) for influenza testing. PMID:21311813
Abe, Tomoteru; Segawa, Yuji; Watanabe, Hidetoshi; Yotoriyama, Tasuku; Kai, Shinichi; Yasuda, Akio; Shimizu, Norio; Tojo, Naoko
Patients with many different conditions are required to take the management of their condition into their own hands and perform Point of Care Testing (POCT) at home. However, this raises quality control issues that would not arise in a clinical setting, since the sample acquisition and testing procedures are not overseen by professional hospital staff. Another major issue, the main
John McGrory; Owen Lynch; Eugene Coyle
Emerging Internet technologies are applied to create and manage a Virtual Laboratory Information System (VLIS), integrated into a distributed healthcare environment. The main objective of the system is to organise the transference of clinical testing from the traditional large central laboratories to a cooperative scheme of several manageable Points of Care Testing (POCTs). In other words, the goal of this
J. L. Villalar; M. T. Arredondo; T. Meneu; V. Traver; M. F. Cabrera; S. Guillen; F. del Pozo
Point-of-care testing (POCT) has evolved from the demand for analytical information more rapidly than is available from central laboratories. By bringing the analysis closer to the patient several process steps have been eliminated, facilitating a shorter time to result and faster management response with improved outcomes. Thus benefits include better therapeutic turnaround times, decreased blood loss as a result of
We show a platform that merges a microfluidic chip with lensless imaging for CD4+ T-lymphocyte counting at resource-limited settings. To capture CD4+ T lymphocytes, anti-CD4 antibody was immobilized on a microfluidic chip. The captured cells were detected by a charge coupled device (CCD) sensor using lensless shadow imaging techniques. Gray scale shadow images of captured cells on the chip (24 mm × 4 mm × 50 ?m) were enumerated in three seconds using an automatic cell counting software. The device achieved 70.2 ± 6.5% capture efficiency, 88.8 ± 5.4% capture specificity for CD4+ T-lymphocytes, 96 ± 1.6% CCD efficiency, and 83.5 ± 2.4% overall platform performance (n = 9 devices). This integrated platform has potential for point-of-care testing (POCT) to rapidly capture, image and count specific cell types from unprocessed whole blood.
Moon, SangJun; Keles, Hasan Onur; Kim, Yun-Gon; Kuritzkes, Daniel; Demirci, Utkan
Background The purpose of this article was to communicate our experience with point-of-care testing (POCT) using Bayer's A1CNow+® device to test glycated hemoglobin (A1C) in the management of diabetes and to share the observations of our quality control efforts. Methods Forty-seven patients' POCT samples were compared with laboratory samples to determine the validity of the POCT sample being drawn. Data collected represent a 10-month time period that were drawn on-site with the following distribution: 36 samples were drawn the same day, 7 samples were drawn 1 day later, 3 samples were drawn within 3 days, and 1 sample was drawn 4 days later. Although all samples were collected on-site, some of the samples were sent to other local branches of nationally recognized laboratories for analysis. Results The range of A1C results for the POCT group was 5.6 to >13%. The range of A1C results for the laboratorydrawn group was 5 to 12.6%. Twenty-four patients had laboratory results that read lower than the result obtained in the clinic, with an A1C range of 5 to 12.6%, and two patients had laboratory results that read exactly the same as the result obtained in the clinic when using POCT. These two individuals had A1C results of 9.1 and 12.6%. Analysis of data collected determined an r value of 0.918 demonstrating agreement between the POCT samples and the laboratory samples. Conclusions POCT with the A1CNow+ is an effective, economical tool for use in a pharmacist-based diabetes clinic that serves a high-risk underserved population. POCT allows the pharmacist the ability to use on-site results to inform patients of their progress, modify their therapy immediately with an immediate face-to-face opportunity to assure understanding, and provide a self-management goal.
Leal, Sandra; Soto-Rowen, Marisa
Point-of-care (POC) or “near-patient” testing allows diagnostic assays to be performed in locations such as the emergency department or intensive care unit where treatment decisions are made and care is delivered based on the results of these assays. Presently, there exist POC immunoassays for several cardiac markers including creatine kinase MB (CK-MB), myoglobin, troponin I, and troponin T that yield
Michael P. Hudson; Robert H. Christenson; L. Kristin Newby; Andrew L. Kaplan; E. Magnus Ohman
Diabetes is a major health concern that is growing rapidly. Daily point-of-care testing (POCT) of one's blood sugar using a glucose meter plays an integral role in managing diabetes. By integrating these self-monitoring devices with a centralized information system both patients and providers can view the blood sugar readings. This capability facilitates collaborative disease management that can lead to better
Mary Lou Ingeholm; Tang Ming-Jye Hu; Maggie Fang; Seong K. Mun; Betty A. Levine
Background Coeliac disease (CD), due to its protean clinical manifestation, is still very under diagnosed in adults and delays in diagnosis may take years and even decades. Simple tools to find cases in primary care may help to identify patients for further diagnostic tests. We have evaluated the usefulness of an on site rapid fingertip whole blood point-of-care test (POCT) for such a purpose. Methods As CD is known to run within families, we tested 148 healthy relatives of 70 Romanian index cases with biopsy-proven CD (87% of all first-degree family members, median age 36 years) for the presence of circulating autoantibodies. In addition to performing the POCT (which measures blood erythrocyte self-TG2-autoantibody complexes) on site, blood was drawn for later evaluations of serum IgA-class endomysial antibodies (EMA). EMA-positive sera were further tested for transglutaminase 2 antibodies (TG2-IgA). All serological parameters were analyzed blindly in a centralized laboratory that had no knowledge of the on site POCT result. Endoscopic small intestinal biopsies was recommended for all POCT- or EMA-test positive subjects. Results In on site testing the POCT was positive in 12/148 first-degree relatives (8%) and all these subjects were also serum EMA-positive. A positive EMA test was found only in one other subject. All remaining 135 healthy first-degree relatives were negative for both POCT and EMA. Four subjects positive for both POCT and EMA were negative for TG2-IgA. Ten out of thirteen of the antibody-positive subjects agreed to undergo endoscopy. The POCT was found to be positive in 8/9 first-degree relatives having coeliac-type mucosal lesions of grade Marsh 2 (n?=?3) or Marsh 3 (n?=?6). The three POCT-positive subjects not agreeing to undergo endoscopy were also both EMA- and TG2-IgA-positive. Conclusion The fingertip whole blood rapid POCT might fulfill the unmet need for a simple and cheap case-finding biomarker for early detection and presumptive diagnosis of CD. Confirmatory studies are warranted in adult case-finding in specialized outpatient clinics and in primary care.
This paper discuses mobile phone (cell phone) and wireless applications for linking patients who manage their healthcare outside the hospital using point of care testing (POCT) to hospital information systems (HIS). Certain medical conditions require patients to manage their healthcare by performing on themselves POC testing and act faithfully on the result. This raises quality control issue, as these POC
John McGrory; Owen Lynch; Eugene Coyle
Background A point-of-care test (POCT) for sexually transmitted infections (STIs), which offers immediate diagnosis resulting in patients receiving diagnosis and treatment in a single visit, has the ability to address some of the STI control needs. However, needs assessment from STI experts and end users about currently available STI POCTs and their future new development has not been evaluated since World Health Organization Sexually Transmitted Diseases Diagnostics Initiative was formed over 15 years ago. Therefore, our objective was to explore the perceptions of the ideal types of STI POCT for use in health care settings. Methodology/Principal Findings A qualitative study, encompassing eight focus groups, was conducted from March 2008 through April 2009. Participants included 6 STD clinic directors, 63 clinicians, and 7 public health/laboratory/epidemiology professionals in the STI field. Discussion topics included currently available POCT, perceived barriers to using POCT in clinics, priority STI for the development of new POCT, and characteristics of the ideal POCT. All discussions were recorded and transcribed verbatim. Themes raised as barriers for current POCT included complexity, long time frames of the so-called “rapid” test, multiple time-driven steps, requiring laboratory technician, difficulty in reading result, interruption of workflow, unreliability, and invasiveness. Chlamydia trachomatis was identified as the priority organism for development of a new STI POCT. Themes indicated for the ideal POCT included rapid turnaround (up to 20 minutes), ease of use, non-invasive, accurate (preferred sensitivity and specificity in the range of high 90s), Clinical Laboratory Improvement Amendments (CLIA)-waived, user-friendly (for both patients and staff), compact, durable, and sturdy. Conclusions/Significance Focus group discussions with STI experts and professionals highlighted chlamydia as the top priority pathogen for POCT development, and identified the qualities of new POCT for STIs. Participants endorsed ease of use, rapid turnaround and high accuracy as essential characteristics of an ideal POCT.
Hsieh, Yu-Hsiang; Hogan, M. Terry; Barnes, Mathilda; Jett-Goheen, Mary; Huppert, Jill; Rompalo, Anne M.; Gaydos, Charlotte A.
Air and ground transport are used for prehospital transport of patients in acute life-threatening situations, and increasingly, critically ill patients undergo interhospital transportation. Results from clinical studies suggest that critical tests performed during the transport of critically ill patients presents a potential opportunity to improve patient care. Our project was to identify, according to the recommendations published at this time, a model of point-of-care testing (POCT) (arterial blood gases analysis and glucose, sodium, potassium, ionized calcium, hematocrit/hemoglobin measurements) in air ambulances. In order to identify the key internal and external factors that are important to achieving our objective, an analysis of the Strengths, Weaknesses, Opportunities, and Threats (SWOT analysis) was incorporated into our planning model prior to starting the project. To allow the entire POCT process (pre-, intra-, and post-analytic steps) to be under the control of the reference laboratory, an experimental model of information technology was applied. Real-time results during transport of critically ill patients must be considered to be an integral part of the patient care process and excellent channels of communication are needed between the intensive care units, emergency medical services and laboratories. With technological and computer advances, POCT during critical care transport will certainly increase in the future: this will be a challenge from a laboratory and clinical context. PMID:20406127
Di Serio, Francesca; Petronelli, Maria Antonia; Sammartino, Eugenio
Point-of-care testing (POCT) has economic and medical benefits in the areas of immediate medical management, resource utilization and time management. Starting with bedside glucose, the Mount Sinai Medical Center has, over the past 11 years, implemented 23 POC tests, spanning complexity from blood gas\\/electrolyte testing to occult blood, in compliance with all regulatory and accreditation requirements. QC data are reviewed
Ellis Jacobs; Karen A Hinson; Judit Tolnai; Elkin Simson
Point of care testing describes testing using handheld or benchtop technology, where the result will be used in the screening for, or the diagnosis and\\/or the management of, disease. It is an alternative to using the services of a centralized facility such as a laboratory. The successful use of point of care testing technology demands that the quality of the
Christopher P. Price
On 6–7 May 1994, the National Academy of Clinical Biochemistry sponsored a conference on point-of-care testing (POCT) in Philadelphia, PA. Several other organizations including the American Association for Clinical Chemistry, the Centers for Disease Control and Prevention, the Clinical Laboratory Management Association, the National Laboratory Training Network Eastern Area Resource Office, and Thomas Jefferson University co-sponsored the program, which brought
As part of a symposium on laboratory medicine, a colloquium on point-of-care testing was held in June 1999 where four experts were invited to produce recommendations and opinions on the use of point-of-care testing under various clinical venues. Each commented on costs for providing POCT services. A total of eleven recommendations and four opinions were rendered and discussed in an
Jocelyn M. Hicks; Rainer Haeckel; Christopher P. Price; Kent Lewandrowski; Alan H. B. Wu
Purpose – The purpose of this paper is to pilot-test the feasibility and impact of protocol-driven point-of-care HbA1c testing on levels of glycemic control and on rates of diabetic regimen intensification in an urban community health center serving low-income patients. Design\\/methodology\\/approach – The paper suggests a primary care process re-design, using point of care finger-stick HbA1c testing under a standing
George Rust; Morna Gailor; Elvan Daniels; Barbara McMillan-Persaud; Harry Strothers; Robert Mayberry
This study aimed to assess intrarater and interrater variability of coagulation point-of-care testing (POCT) using ROTEM delta operated by trained staff. Arterial blood samples were taken from 43 anesthetized piglets aged up to 6 weeks and weighing 4-6 kg. The following clotting measurements were recorded: clotting time, clot formation time (CFT), maximum clot firmness (MCF) and alpha angle using ROTEM delta assays ExTEM, InTEM, FibTEM and ApTEM. Intrarater variability was assessed when a single operator performed the same assay simultaneously in all four channels of the ROTEM device. Interrater variability was assessed by two different operators simultaneously performing the same assay. Variance components of the data were analyzed using linear mixed modeling. Three hundred and forty-three tests from 86 samples were loaded and analyzed. The intraclass correlation coefficient (ICC) was more than 0.7 for clotting measurements except for CFT and alpha in InTEM. For intrarater and interrater assessment, different relative variability for the ROTEM measurements were found with consistently higher variability for clotting time and CFT and lower variability of MCF and alpha angle. Interrater variability was not statistically significant as supported using Akaike's information criterion. Piglet coagulation testing using ROTEM delta showed a high ICC. Variability was significantly lower in MCF and angle alpha compared with clotting time and CFT. No further variability was added by a second user. Based on these data, ROTEM delta appears to be suitable as POCT. PMID:21822125
Mauch, Jacqueline; Spielmann, Nelly; Hartnack, Sonja; Madjdpour, Caveh; Kutter, Annette P N; Bettschart-Wolfensberger, Regula; Weiss, Markus; Haas, Thorsten
To develop a miniature complete blood count (CBC) analyzer for point-of-care testing (POCT), a disposable MEMS hemoglobin and volume measurement sensor was discussed. The light emitting diode (LED) and photo detector were arranged in the mainframe to allow repeated use. However, the fluidic path, optical cell, and optical waveguides with quartz optical fiber (?250?m) were arranged in the MEMS disposable chip. The sensors were fabricated successfully using an SU-8 photolithography process. The proposed volume measurement sensor was shown to detect the presence of sample liquid at two locations with a single light source and photo detector. The hemoglobin concentration sensor provided good linearity in the range of normal physiological values to decreased values requiring immediate care. The new MEMS hemoglobin and volume measurement sensor demonstrated potential application as a miniature CBC analyzer.
Tanabe, Rikiya; Hata, Seiichi; Shimokohbe, Akira
Background External quality assurance (EQA) programmes, which are routinely used in laboratories, have not been widely implemented for point-of- care tests (POCTs). A study was performed in ten health centres in Tanzania, to implement the use of dried blood spots (DBS) as an EQA method for HIV and syphilis (POCTs). Method DBS samples were collected for retesting at a reference laboratory and the results compared to the POCT results obtained at the clinic. In total, 2341 DBS samples were collected from 10 rural health facilities over a period of nine months, of which 92.5% were correctly collected and spotted. Results The EQA method was easily implemented by healthcare workers under routine conditions in Northern Tanzania. For HIV, 967 out of 972 samples (99.5%) were concordant between DBS and POCT results. For syphilis, the sensitivity of syphilis tests varied between clinics with a median of 96% (25th and 75th quartile; 95-98%). The specificity of syphilis POCT was consistent compared to laboratory based test using DBS, with a median of 96% (25th and 75th quartiles; 95-98%). Conclusion Overall, the quality of testing varied at clinics and EQA results can be used to identify clinics where healthcare workers require remedial training, suggesting the necessity for stringent quality assurance programmes for POC testing. As Tanzania embarks on scaling up HIV and syphilis testing, DBS can be a useful and robust tool to monitor the quality of testing performed by healthcare workers and trigger corrective action to ensure accuracy of test results.
In veterinary medicine, point-of-care testing (POCT) techniques have become popular, since they provide immediate results and only small amounts of blood are needed. However, their accuracy is controversial. Pigs are often used for research purposes and accurate measurement of haemoglobin (Hb) is important during invasive procedures. The aim of this study was to evaluate two different Hb POCT devices in neonatal pigs. A prospective study with 57 pigs of 3-6 weeks of age, weighing 4.1-6.2 kg (median 5.1 kg) was performed. Fifty-seven blood samples were analysed for Hb using a conductivity-based and a photometrical POCT device and compared with a photometrical reference method. Statistical analysis was performed with Bland-Altman analysis, Spearman correlation and Passing-Bablok regression analysis. Hb values ranged from 32 to 108 g/L (median 80 g/L) using the reference method. The bias of the photometrical method (HemoCue(®)) to the reference method was -1 g/L, with limits of agreement (LOA) of -7 to 6 g/L. The conductivity-based method (i-STAT(®)) had a bias of -15 g/L with LOA from -24 to -6 g/L. There was a significant association between protein values and the bias of i-STAT versus CellDyn (r(2) = 0.27, P < 0.05) but not with the bias of HemoCue versus CellDyn (r(2) = 0.001, P = 0.79). The lower the protein values were, the lower the Hb values were measured by the i-STAT. The conductivity-based measurement of Hb constantly underestimated Hb values, whereas the photometrical method demonstrated a better accuracy and is therefore more reliable for on-site measurement of Hb in pigs. PMID:22087030
Kutter, Annette P N; Mauch, Jacqueline Y; Riond, Barbara; Martin-Jurado, Olga; Spielmann, Nelly; Weiss, Markus; Bettschart-Wolfensberger, Regula
We examined the basic performance of "Microsemi LC-667CRP" (LC-667, HORIBA, Ltd.) which has been newly developed as compact laboratory instrument capable of simultaneous measuring of complete blood count (CBC) including 3-part differentials of white blood cells (WBC) and C-reactive protein (CRP) using whole blood anticoagulated with ethylenediaminetetraacetic acid (EDTA). We found that CBC and CRP were intra-assay-reproducible (n = 10, CVs < 5.0%). They also showed the good linearity and no definite carry-over. Concerning the WBC differentials, percentage of monocytes (MON%) showed less intra-assay reproducibility compared with those of granulocytes (GRA%) and lymphocytes (LYM%). We also evaluated the correlation of values obtained by LC-667 and routinely used instruments in our institute. Concerning the CBC and WBC differentials, excellent correlations were found between LC-667CRP and XE-2100 (SYSMEX CORPORATION) except MON%. In addition, whole blood CRP as well as plasma and serum CRP measured by LC-667 also showed the good correlations with serum CRP measured by 7600 (Hitachi High Technologies Corporation). From these findings, LC-667 was revealed to produce the clinically reliable data using only 18 microL of sample volume in 4 minutes. Point of care testing (POCT) has been developed as the laboratory system performed at or near the site of patient to reduce the turn around time. Therefore, LC-667 seemed useful in POCT for the patients with acute inflammatory disease especially in pediatrics. PMID:20715509
Inaba, Tohru; Yuasa, Sohichi; Taniguchi, Hiroshi; Nakashima, Koyo; Nagaoka, Hiroki; Fujita, Naohisa
Abstract Objective To evaluate the performance of a newly developed point-of-care test (POCT) for the detection of measles-specific IgM antibodies in serum and oral fluid specimens and to assess if measles virus nucleic acid could be recovered from used POCT strips. Methods The POCT was used to test 170 serum specimens collected through measles surveillance or vaccination programmes in Ethiopia, Malaysia and the Russian Federation: 69 were positive for measles immunoglobulin M (IgM) antibodies, 74 were positive for rubella IgM antibodies and 7 were positive for both. Also tested were 282 oral fluid specimens from the measles, mumps and rubella (MMR) surveillance programme of the United Kingdom of Great Britain and Northern Ireland. The Microimmune measles IgM capture enzyme immunoassay was the gold standard for comparison. A panel of 24 oral fluids was used to investigate if measles virus haemagglutinin (H) and nucleocapsid (N) genes could be amplified by polymerase chain reaction directly from used POCT strips. Findings With serum POCT showed a sensitivity and specificity of 90.8% (69/76) and 93.6% (88/94), respectively; with oral fluids, sensitivity and specificity were 90.0% (63/70) and 96.2% (200/208), respectively. Both H and N genes were reliably detected in POCT strips and the N genes could be sequenced for genotyping. Measles virus genes could be recovered from POCT strips after storage for 5 weeks at 20–25 °C. Conclusion The POCT has the sensitivity and specificity required of a field-based test for measles diagnosis. However, its role in global measles control programmes requires further evaluation.
Slibinskas, Rimantas; Chua, Kaw Bing; Nigatu, Wondatir; Brown, Kevin E; Sasnauskas, Kestutis; Samuel, Dhanraj; Brown, David
We demonstrate an integrated platform that merges a microfluidic chip with lensless imaging to target CD4(+) T-lymphocyte counts for HIV point-of-care testing at resource-limited settings. The chips were designed and fabricated simply with a laser cutter without using expensive cleanroom equipment. To capture CD4(+) T-lymphocytes from blood, anti-CD4 antibody was immobilized on only one side of the microfluidic chip. These captured cells were detected through an optically clear chip using a charge coupled device (CCD) sensor by lensless shadow imaging techniques. Gray scale image of the captured cells in a 24 mm x 4 mm x 50 microm microfluidic chip was obtained by the lensless imaging platform. The automatic cell counting software enumerated the captured cells in 3s. Captured cells were also imaged with a fluorescence microscope and manually counted to characterize functionality of the integrated platform. The integrated platform achieved 70.2+/-6.5% capture efficiency, 88.8+/-5.4% capture specificity for CD4(+) T-lymphocytes, 96+/-1.6% CCD efficiency, and 83.5+/-2.4% overall platform performance (n=9 devices) compared to the gold standard, i.e. flow cytometry count. The integrated system gives a CD4 count from blood within 10 min. The integrated platform points a promising direction for point-of-care testing (POCT) to rapidly capture, image and count subpopulations of cells from blood samples in an automated matter. PMID:19467854
Moon, Sangjun; Keles, Hasan Onur; Ozcan, Aydogan; Khademhosseini, Ali; Haeggstrom, Edward; Kuritzkes, Daniel; Demirci, Utkan
We demonstrate an integrated platform that merges a microfluidic chip with lensless imaging to target CD4+ T-lymphocyte counts for HIV point-of-care testing at resource-limited settings. The chips were designed and fabricated simply with a laser cutter without using expensive cleanroom equipment. To capture CD4+ T lymphocytes from blood, anti-CD4 antibody was immobilized on only one side of the microfluidic chip. These captured cells were detected through an optically clear chip using a charge coupled device (CCD) sensor by lensless shadow imaging techniques. Gray scale image of the captured cells in a 24 mm × 4 mm × 50 ?m microfluidic chip was obtained by the lensless imaging platform. The automatic cell counting software enumerated the captured cells in three seconds. Captured cells were also imaged with a fluorescence microscope and manually counted to characterize functionality of the integrated platform. The integrated platform achieved 70.2 ± 6.5% capture efficiency, 88.8 ± 5.4% capture specificity for CD4+ T-lymphocytes, 96 ± 1.6% CCD efficiency, and 83.5 ± 2.4% overall platform performance (n = 9 devices) compared to the gold standard, i.e. flow cytometry count. The integrated system gives a CD4 count from blood within 10 minutes. The integrated platform points a promising direction for point-of-care testing (POCT) to rapidly capture, image and count subpopulations of cells from blood samples in an automated matter.
Moon, SangJun; Keles, Hasan Onur; Ozcan, Aydogan; Khademhosseini, Ali; Haeggstrom, Edward; Kuritzkes, Daniel; Demirci, Utkan
The prehospital environment has not been studied for point-of-care testing. Therefore, the authors' helicopter program evaluated the performance of the i-STAT Portable Clinical Analyzer, a rapid point-of-care, hand-held instrument. The primary aim of the study was to determine if the i-STAT Portable Clinical Analyzer could be used in the field to assess patient status in flight, and to allow the flight crew to intervene immediately, thus delivering a more stable patient to the emergency room. Imprecision and initial split-sample comparative studies with the Portable Clinical Analyzer were completed in the hospital satellite laboratory and clinical chemistry laboratory. Comparison studies were performed on patient samples drawn and analyzed in the helicopter and subsequently analyzed in the satellite and clinical chemistry laboratories. The only significant differences observed were with glucose. The glucose discrepancies were probably due to the time delay between collection of the specimen in the helicopter and subsequent analysis in the laboratory. Following this initial validation, the i-STAT Portable Clinical Analyzer was used on 81 patients transported by the flight crew. The tests performed in the helicopter include sodium, potassium, glucose, and hematocrit/hemoglobin concentrations. Fifteen (18.5%) of the patients were treated with transfusions, glucose, or insulin based on the Portable Clinical Analyzer results. Other identified needs include blood gas analysis (in process) and use of point-of-care testing in the fixed-wing environment. PMID:7484950
Herr, D M; Newton, N C; Santrach, P J; Hankins, D G; Burritt, M F
The national Quality Assurance for Aboriginal Medical Services (QAAMS) Program, in which point-of-care testing (POCT) for haemoglobin A1c (HbA1c) and urine albumin:creatinine ratio (ACR) is performed for diabetes management in 65 Australian Aboriginal medical services, is now embedded in the practice of diabetes care across Indigenous Australia. This paper documents the results of a detailed survey to assess levels of
Mark DS Shephard
A pragmatic cluster randomised controlled trial to evaluate the safety, clinical effectiveness, cost effectiveness and satisfaction with point of care testing in a general practice setting – rationale, design and baseline characteristics
BACKGROUND: Point of care testing (PoCT) may be a useful adjunct in the management of chronic conditions in general practice (GP). The provision of pathology test results at the time of the consultation could lead to enhanced clinical management, better health outcomes, greater convenience and satisfaction for patients and general practitioners (GPs), and savings in costs and time. It could
Caroline Laurence; Angela Gialamas; Lisa Yelland; Tanya Bubner; Philip Ryan; Kristyn Willson; Briony Glastonbury; Janice Gill; Mark Shephard; Justin Beilby
The purpose of this study was to determine the diagnostic performance of a point-of-care test (POCT) for detection of anti-mutated citrullinated vimentin (anti-MCV) and rheumatoid factor (RF) in early rheumatoid arthritis (RA) with 2 years of disease duration or less. Additionally, we evaluated the agreement of these tests when using EDTA whole blood and capillary blood. Patients with RA and other rheumatic disorders were consecutively recruited from the rheumatology outpatient clinic. The POCT for detection of anti-MCV and RF using capillary blood and EDTA whole blood was performed in 78 patients with early RA, 55 patients with other rheumatic disorders, and 55 healthy blood donors. The sensitivity and specificity of anti-MCV POCT in patients with early RA were 64 and 97 %, respectively, while the sensitivity and specificity of RF POCT were 51 and 95 %, respectively. The positive likelihood ratio of the POCT for anti-MCV was higher than those for RF (23.5 vs 9.4). The negative likelihood was 0.37 for anti-MCV and 0.52 for RF. There were three cases with false positive for anti-MCV including a patient with psoriatic arthritis and the other two with systemic sclerosis. The agreement between capillary blood and EDTA whole blood testing for anti-MCV and RF was low to moderate with Cohen's kappa of 0.58 and 0.49, respectively. This POCT for detection of anti-MCV and RF yielded high specificity and may be a valuable tool for the diagnosis of early RA. Using this POCT with EDTA whole blood instead of capillary blood is not recommended. PMID:24577818
Rojanasantikul, Preeda; Pattrapornpisut, Prapa; Anuruckparadorn, Kulvara; Katchamart, Wanruchada
Besides the use of traditional laboratory resources, the diagnosis of anemia can also be accomplished by assessing hemoglobin (Hb) concentration with point-of-care testing (POCT) devices such as the HemoCue test systems. In several situations, these devices might suitably replace traditional laboratory testing, including several areas of health care where a very rapid Hb measurement might be required to make immediate therapeutic decisions. The use of these devices, however, should fulfill some basic criteria, including economic, clinical, and regulatory issues; appropriate training of the users and knowledge of test requirements, performance, limitations, and potential interferences; the use of venous and arterial sampling, when possible; and a rigorous quality assessment, which should be under the responsibility of laboratory professionals. Because of its optimal performance along with the fact that the HemoCue is probably one of the most commonly used devices worldwide, the aim of this article is to review the literature data about the performance of this test system as compared with laboratory reference testing estimations and according to the biological matrix. PMID:22961038
Sanchis-Gomar, Fabian; Cortell-Ballester, José; Pareja-Galeano, Helios; Banfi, Giuseppe; Lippi, Giuseppe
The ratio of glycated albumin to albumin concentration in serum is termed the glycated albumin (GA) value. The GA value provides a time-averaged index of the state of glycemic control for the previous 2 weeks. In this study, a dry chemistry system (GA monitor) via an enzymatic method was proposed in order to provide a GA value measurement for point of care testing (POCT). The GA monitor was made from three devices a set of test-tapes, a test-strip and an optical analyzer. A GA test-tape, a ketoamine test-tape and an albumin test-tape were enclosed in the fabricated test-strip. Time-course changes of the optical characteristics were evaluated using the test-strip. It was found that the three test tapes must be enclosed in the test-strip to create a dry chemistry system for small sample volumes (20 microl). A temperature control unit, which could hold the temperature of the GA test-tape at 45 degrees C and at 25 degrees C for the other two types of test-tape was incorporated into the optical analyzer. With the GA test-tape held separately and controlled at 45 degrees C, the analytical time decreased to one-third of the time taken for the three tapes at 25 degrees C. The analytical accuracy of the three types of test-tape showed favorable results, with R2 values of 0.96-0.98 and coefficients of variation (CV) of 2.4-6.8%. Compared with a commercially available liquid chemistry system, the analytical accuracy of the GA monitor exhibited a relatively favorable linearity of R=0.82. According to these results, a new GA value analytical system was realized, in which the GA value could be assayed within five minutes using only 20 microl of blood sample with a disposable test-strip. This system could potentially be used for clinical purposes as test equipment for rapid and efficient POCT. PMID:16076431
Yamaguchi, Masaki; Kambe, Shigenori; Eto, Takashi; Yamakoshi, Masaru; Kouzuma, Takuji; Suzuki, Nobuyuki
Health economics has been an established feature of the research, policymaking, practice and management in the delivery of healthcare. However its role is increasing as the cost of healthcare begins to drive changes in most healthcare systems. Thus the output from cost effectiveness studies is now being taken into account when making reimbursement decisions, e.g. in Australia and the United Kingdom. Against this background it is also recognised that the health economic tools employed in healthcare, and particularly the output from the use of these tools however, are not always employed in the routine delivery of services. One of the notable consequences of this situation is the poor record of innovation in healthcare with respect to the adoption of new technologies, and the realisation of their benefits. The evidence base for the effectiveness of diagnostic services is well known to be limited, and one consequence of this has been a very limited literature on cost effectiveness. One reason for this situation is undoubtedly the reimbursement strategies employed in laboratory medicine for many years, simplistically based on the complexity of the test procedure, and the delivery as a cost-per-test service. This has proved a disincentive to generate the required evidence, and little effort to generate an integrated investment and disinvestment business case, associated with care pathway changes. Point-of-care testing creates a particularly challenging scenario because, on the one hand, the unit cost-per-test is larger through the loss of the economy of scale offered by automation, whilst it offers the potential of substantial savings through enabling rapid delivery of results, and reduction of facility costs. This is important when many health systems are planning for complete system redesign. We review the literature on economic assessment of point-of-care testing in the context of these developments. PMID:24151342
St John, Andrew; Price, Christopher P
Health economics has been an established feature of the research, policymaking, practice and management in the delivery of healthcare. However its role is increasing as the cost of healthcare begins to drive changes in most healthcare systems. Thus the output from cost effectiveness studies is now being taken into account when making reimbursement decisions, e.g. in Australia and the United Kingdom. Against this background it is also recognised that the health economic tools employed in healthcare, and particularly the output from the use of these tools however, are not always employed in the routine delivery of services. One of the notable consequences of this situation is the poor record of innovation in healthcare with respect to the adoption of new technologies, and the realisation of their benefits. The evidence base for the effectiveness of diagnostic services is well known to be limited, and one consequence of this has been a very limited literature on cost effectiveness. One reason for this situation is undoubtedly the reimbursement strategies employed in laboratory medicine for many years, simplistically based on the complexity of the test procedure, and the delivery as a cost-per-test service. This has proved a disincentive to generate the required evidence, and little effort to generate an integrated investment and disinvestment business case, associated with care pathway changes. Point-of-care testing creates a particularly challenging scenario because, on the one hand, the unit cost-per-test is larger through the loss of the economy of scale offered by automation, whilst it offers the potential of substantial savings through enabling rapid delivery of results, and reduction of facility costs. This is important when many health systems are planning for complete system redesign. We review the literature on economic assessment of point-of-care testing in the context of these developments.
St John, Andrew; Price, Christopher P
Nucleic acid testing for infectious diseases at the point of care is beginning to enter clinical practice in developed and developing countries; especially for applications requiring fast turnaround times, and in settings where a centralized laboratory approach faces limitations. Current systems for clinical diagnostic applications are mainly PCR-based, can only be used in hospitals, and are still relatively complex and expensive. Integrating sample preparation with nucleic acid amplification and detection in a cost-effective, robust, and user-friendly format remains challenging. This review describes recent technical advances that might be able to address these limitations, with a focus on isothermal nucleic acid amplification methods. It briefly discusses selected applications related to the diagnosis and management of tuberculosis, HIV, and perinatal and nosocomial infections.
Niemz, Angelika; Ferguson, Tanya M.; Boyle, David S.
Background Evidence of the clinical benefit of 3-in-1 point-of-care testing (POCT) for cardiac troponin T (cTnT), N-terminal pro-brain natriuretic peptide (NT-proBNP) and D-dimer in cardiovascular risk stratification at primary care level for diagnosing acute coronary syndromes (ACS), heart failure (HF) and thromboembolic events (TE) is very limited. The aim of this study is to analyse the diagnostic accuracy of POCT in primary care. Methods Prospective multicentre controlled trial cluster-randomised to POCT-assisted diagnosis and conventional diagnosis (controls). Men and women presenting in 68 primary care practices in Zurich County (Switzerland) with chest pain or symptoms of dyspnoea or TE were consecutively included after baseline consultation and working diagnosis. A follow-up visit including confirmed diagnosis was performed to determine the accuracy of the working diagnosis, and comparison of working diagnosis accuracy between the two groups. Results The 218 POCT patients and 151 conventional diagnosis controls were mostly similar in characteristics, symptoms and pre-existing diagnoses, but differed in working diagnosis frequencies. However, the follow-up visit showed no statistical intergroup difference in confirmed diagnosis frequencies. Working diagnoses overall were significantly more correct in the POCT group (75.7% vs 59.6%, p = 0.002), as were the working diagnoses of ACS/HF/TE (69.8% vs 45.2%, p = 0.002). All three biomarker tests showed good sensitivity and specificity. Conclusion POCT confers substantial benefit in primary care by correctly diagnosing significantly more patients. Trial registration DRKS: DRKS00000709
A new, highly sensitive fluorescence immunoassay for a TIRF (total internal reflection)-based point-of-care testing (POCT) device was developed for the detection of procalcitonin (PCT), a specific and early marker for sepsis and microbial infections. The immunoassay was performed on a bench-top system that fulfilled all the necessary characteristics of a POCT application, including a short measurement time (<9min), no sample pre-treatment requirements and application directly near patients. New rat monoclonal antibodies targeting PCT were screened and characterized. The best combinations of antibodies were then integrated into single-use cartridges, and the reduction of nonspecific binding was achieved by supplying suitable additives. Moreover, human recombinant PCT (hrPCT) for use as a standard was developed in the native form of hPCT in plasma (PCT1-116, PCT3-116). The assay achieves the required sensitivity range in human plasma to allow reliable differentiation between healthy persons and varying stages of infection severity (LOD=0.04ng/mL; LOQ=0.12ng/mL). Furthermore, the developed PCT assay can be applied in whole human blood with an adequate sensitivity (LOD=0.02ng/mL; LOQ=0.09ng/mL). To the best of our knowledge, this is the first diagnostic test for sepsis to use whole blood, which is a crucial requirement for POCT. We were able to detect native PCT in patient samples and showed a good correlation (R(2)=0.988) with the results of the Kryptor(®) device from BRAHMS, a state of the art device for the detection of PCT. PMID:24732603
Rascher, Daniela; Geerlof, Arie; Kremmer, Elisabeth; Krämer, Petra; Michael, Schmid; Hartmann, Anton; Rieger, Martin
A fully automated point-of-care testing (POCT) system with a surface acoustic wave (SAW) immunosensor was developed for rapid and sensitive detection of cardiac troponin I (cTnI) in body fluid (plasma and whole blood). The assay, based on gold nanoparticle sandwich immunoassay and subsequent gold staining, was performed on the SAW immunosensor packaged inside a disposable microfluidic cartridge. The entire fluidic process, including plasma separation, reagent transport, metering, and mixing, was carried out by controlling the centrifugal force acting on the rotating cartridge and laser-irradiated ferrowax microvalves. On investigation of sensor response to various cTnI concentrations, the system exhibited a high performance with a detection limit of 6.7 pg mL(-1), and the coefficient of variation was less than 10% over the entire test range (10 pg mL(-1) to 25 ng mL(-1)). On comparing this POCT system with a clinically utilized system in a physical laboratory (Centaur® XP; Siemens), a correlation coefficient of 0.998 was found, validating the diagnostic capability of the SAW immunosensor. PMID:23478433
Lee, Woochang; Jung, Jaeyeon; Hahn, Young Ki; Kim, Sang Kyu; Lee, Yeolho; Lee, Joonhyung; Lee, Tae-Han; Park, Jin-Young; Seo, Hyejung; Lee, Jung Nam; Oh, Jin Ho; Choi, Youn-Suk; Lee, Soo Suk
Point-of-care applications are gaining increasing interest in clinical diagnostics and emergency applications. Biosensors are used to monitor the biomolecular interaction process between a disease biomarker and a recognition element such as a reagent. Essential are the quality and selectivity of the recognition elements and assay types used to improve sensitivity and to avoid nonspecific interactions. In addition, quality measures are influenced by the detection principle and the evaluation strategies. For these reasons, this review provides a survey and validation of recognition elements, assays, and various types of detection methods for point-of-care testing (POCT) platforms. Common applications of clinical parameters are discussed and considered. In this ever-changing field, a snapshot of current applications is needed. We provide such a snapshot by way of a table including literature citations and also discuss these applications in more detail throughout. PMID:25014344
The aim of diagnostic point-of-care testing is to minimise the time to obtain a test result, thereby allowing clinicians and patients to make a quick clinical decision. Because point-of-care tests are used in resource-limited settings, the benefits need to outweigh the costs. To optimise point-of-care testing in resource-limited settings, diagnostic tests need rigorous assessments focused on relevant clinical outcomes and operational costs, which differ from assessments of conventional diagnostic tests. We reviewed published studies on point-of-care testing in resource-limited settings, and found no clearly defined metric for the clinical usefulness of point-of-care testing. Therefore, we propose a framework for the assessment of point-of-care tests, and suggest and define the term test efficacy to describe the ability of a diagnostic test to support a clinical decision within its operational context. We also propose revised criteria for an ideal diagnostic point-of-care test in resource-limited settings. Through systematic assessments, comparisons between centralised testing and novel point-of-care technologies can be more formalised, and health officials can better establish which point-of-care technologies represent valuable additions to their clinical programmes. PMID:24332389
Drain, Paul K; Hyle, Emily P; Noubary, Farzad; Freedberg, Kenneth A; Wilson, Douglas; Bishai, William R; Rodriguez, William; Bassett, Ingrid V
A paper-based immunodevice was fabricated for point-of-care test (POCT). The array device was simple and easily assembled. It comprised as many as 4×10 detection points on a single paper array. The immunosensor array was prepared by covalently immobilizing capture antibodies on corresponding working zone on a disposable paper array. With a sandwich-type immunoreaction, the CuO nanoparticles (CuO NPs)-labeled secondary antibody (Ab2) bioconjugates were captured in each working zone. The coordination of dithizone (DZ) at the surface of CdTe quantum dots (CdTe QDs) could strongly quench the green emission of CdTe QDs by a fluorescence resonance energy transfer (FRET) mechanism. After the Cu(2+) was released from CuO NPs-Ab2, the fluorescence of CdTe QDs-DZ was "turn-on". The fluorescence intensity would increase with the increasing of analytes. The calibration plot showed a good linear relationship between the fluorescence intensity and the logarithm value of the analytes concentration with the low detection limit. The immunosensor array was performed for cancer screening. The high throughput, low-cost, acceptable stability, reproducibility, sensitivity and accuracy showed good applicability of the proposed multiplex immunoassay in clinical diagnosis. The results indicated that the device could be applied to comprehensive sample and point-of-care detection. PMID:23370173
Ge, Shenguang; Ge, Lei; Yan, Mei; Song, Xianrang; Yu, Jinghua; Liu, Shanshan
Type 2 diabetes mellitus and its major complication, renal disease, represent one of the most significant contemporary health problems facing Australia’s Indigenous Aboriginal People. The Australian Government-funded Quality Assurance for Aboriginal Medical Services Program (QAAMS) provides a framework by which on-site point-of-care testing (POCT) for haemoglobin A1c (HbA1c) and now urine albumin:creatinine ratio (ACR) can be performed to facilitate better diabetes management in Aboriginal medical services. This paper provides updated evidence for the analytical quality of POCT in the QAAMS Program. The median imprecision for point-of-care (POC) HbA1c and urine ACR quality assurance (QA) testing has continually improved over the past six and half years, stabilising at approximately 3% for both analytes and proving analytically sound in Aboriginal hands. For HbA1c, there was no statistical difference between the imprecision achieved by QAAMS and laboratory users of the Bayer DCA 2000 since the QAAMS program commenced (QAAMS CV 3.6% ± 0.52, laboratory CV 3.4% ± 0.42; p = 0.21, paired t-test). The Western Pacific Island of Tonga recently joined the QAAMS HbA1c Program indicating that the QAAMS model can also be applied internationally in other settings where the prevalence of diabetes is high.
Shephard, Mark DS; Gill, Janice P
Type 2 diabetes mellitus and its major complication, renal disease, represent one of the most significant contemporary health problems facing Australia's Indigenous Aboriginal People. The Australian Government-funded Quality Assurance for Aboriginal Medical Services Program (QAAMS) provides a framework by which on-site point-of-care testing (POCT) for haemoglobin A1c (HbA(1c)) and now urine albumin:creatinine ratio (ACR) can be performed to facilitate better diabetes management in Aboriginal medical services. This paper provides updated evidence for the analytical quality of POCT in the QAAMS Program. The median imprecision for point-of-care (POC) HbA(1c) and urine ACR quality assurance (QA) testing has continually improved over the past six and half years, stabilising at approximately 3% for both analytes and proving analytically sound in Aboriginal hands. For HbA(1c), there was no statistical difference between the imprecision achieved by QAAMS and laboratory users of the Bayer DCA 2000 since the QAAMS program commenced (QAAMS CV 3.6% +/- 0.52, laboratory CV 3.4% +/- 0.42; p = 0.21, paired t-test). The Western Pacific Island of Tonga recently joined the QAAMS HbA(1c) Program indicating that the QAAMS model can also be applied internationally in other settings where the prevalence of diabetes is high. PMID:17581642
Shephard, Mark D S; Gill, Janice P
Background Point of Care testing (POCT) provides on-site, rapid, accessible results. With current South African anti-retroviral treatment guidelines, up to 4 fingersticks /patient/clinic visit could be required if utilizing POC. We determined the feasibility and accuracy of a nurse performing multiple POCT on multiple fingersticks followed by simplification of the process by performance of multiple POC on a single fingerstick. Method and Findings Random HIV positive adult patients presenting at a HIV treatment clinic in South Africa, for ART initiation/ monitoring, were approached to participate in the study between April-June 2012. Phase I: n=150 patients approached for multiple POCT on multiple fingersticks. Phase II: n=150 patients approached for multiple POCT on a single fingerstick. The following POC tests were performed by a dedicated nurse: PIMA (CD4), HemoCue (hemoglobin), Reflotron (alanine aminotransferase, creatinine). A venepuncture specimen was taken for predicate laboratory methodology. Normal laboratory ranges and Royal College of Pathologists Australasia (RCPA) allowable differences were used as guidelines for comparison. In 67% of participants, ?3 tests were requested per visit. All POCT were accurate but ranged in variability. Phase I: Hemoglobin was accurate (3.2%CV) while CD4, alanine aminotransferase and creatinine showed increased variability (16.3%CV; 9.3%CV; 12.9%CV respectively). PIMA generated a misclassification of 12.4%. Phase II: Hemoglobin, alanine aminotransferase and creatinine showed good accuracy (3.2%CV, 8.7%CV, 6.4%CV respectively) with increased variability on CD4 (12.4%CV) but low clinical misclassification (4.1%). No trends were observed for the sequence in which POC was performed on a single fingerstick. Overall, PIMA CD4 generated the highest error rate (16-19%). Conclusions Multiple POCT for ART initiation and/or monitoring can be performed practically by a dedicated nurse on multiple fingersticks. The process is as accurate as predicate methodology and can be simplified using a single fingerstick.
Gous, Natasha; Scott, Lesley; Potgieter, Joachim; Ntabeni, Lumka; Enslin, Sharon; Newman, Ronel; Stevens, Wendy
Objectives The purpose of this study was to design an integrated data management system based on the POCT1-A2, LIS2-A, LIS2-A2, and HL7 standard to ensure data interoperability between mobile equipment, such as point-of-care testing equipment and the existing hospital data system, its efficiency was also evaluated. Methods The method of this study was intended to design and realize a data management system which would provide a solution for the problems that occur when point-of-care testing equipment is introduced to existing hospital data, after classifying such problems into connectivity, integration, and interoperability. This study also checked if the data management system plays a sufficient role as a bridge between the point-of-care testing equipment and the hospital information system through connection persistence and reliability testing, as well as data integration and interoperability testing. Results In comparison with the existing system, the data management system facilitated integration by improving the result receiving time, improving the collection rate, and by enabling the integration of disparate types of data into a single system. And it was found out that we can solve the problems related to connectivity, integration and interoperability through generating the message in standardized types. Conclusions It is expected that the proposed data management system, which is designed to improve the integration point-of-care testing equipment with existing systems, will establish a solid foundation on which better medical service may be provided by hospitals by improving the quality of patient service.
Park, Ki Sang; Heo, Hyuk
Introduction A point of care test (POCT) for Chlamydia trachomatis detection is an urgent public health need. Technology advances in diagnostics have made solutions possible. Yet no reliable POCT exist. Our goal was to address the gap between chlamydia POCT needs and successful POCT development by determining which characteristics of POCT tests are most critical and if any flexibility in the attributes assigned those characteristics exist between technology developer and end user. Methods We employed a process known as WALEX (Warfare Analysis Laboratory Exercise) in combination with Design of Experiment (DOE) methodology using discrete choice experiments (DCE), to describe the attributes of the most realistic, rather than the most ideal POCT. The WALEX was conducted as interactive oral and simultaneous electronic discussion among experts with differing expertise, but linked by a common interest in development of a chlamydia POCT. Results Our studies demonstrated which features of the ideal chlamydia POCT were considered critical to test acceptance by users and which were open to negotiation. In particular, end users were more lenient on the requirement for the fastest ideal test and the lowest one time instrument costs, if the requirement for higher throughput, lowest cost and vaginal sample source collection were preserved. DOE methods used in forced choice question design provided confirmation of opinions derived from oral and electronic WALEX comments Conclusions The WALEX in combination with DCE helped us achieve our goal in identifying the gaps in the chlamydia POCT and determining the most realistic solutions to bridge those gaps.
Jackman, Joany; Uy, Manny; Hsieh, Yu-Hsiang; Rompalo, Anne; Hogan, Terry; Huppert, Jill; Jett-Goheen, Mary; Gaydos, Charlotte
Reversing and arresting the epidemic of HIV are a challenge for any country. Early diagnosis and rapid initiation of treatment remain a key strategy in the control of HIV. Technological advances in the form of low-cost rapid point-of-care tests have completely transformed the diagnosis and management of HIV, especially in resource limited settings, where health infrastructure is poor and timely access to medical care is a challenge. Point-of-care devices have proven to be easy to transport, operate, and maintain, and also lower-skilled staff is equally able to perform these tests as compared to trained laboratory technicians. Point-of-care tests allow rapid detection of HIV allowing for rapid initiation of therapy, monitoring of antiretroviral therapy and drug toxicity, and detection of opportunistic infections and associated illnesses.
Arora, D. R.; Maheshwari, Megha; Arora, B.
The standard turnaround time for acute care laboratory testing in tertiary care institutions is typically less than 15 minutes for blood gas or electrolyte values. From a clinical perspective, however, the desirable turnaround time is more on the order of 5 minutes, and this is technically achievable. The 15-minute standard can be met with strategically located STAT laboratories. To achieve a turnaround time of 5 minutes, it is necessary to move the "laboratory" closer to the patient and to have more than one instrument available. This latter configuration is called near or bedside patient testing. Why the 5-minute standard is not used universally throughout the nation is probably related to differing perspectives on "cost" and "quality." As manufacturers, hospitals and laboratories address the issue of rapid turnaround time in acute care settings, the 5-minute standard may become more widespread. Direct costs have been decreasing as more manufacturers enter the market for acute care testing. The overall quality is also improving, not only in the engineering features built into the instruments, but also as nonlaboratory staff gain skill in performing the testing. As more sites implement POCT, standards and guidelines for managing testing outside of the laboratory are being established. Solutions to preanalytic problems are being developed and implemented. POCT testing for blood gases and electrolytes was once considered to lie in the future but is now commonplace and may one day become the standard of care. PMID:11396086
Cox, C J
Rapid and accurate point of care testing is of great concern, especially in terms of detecting infectious disease outbreaks in developing countries having high population burdens. While numerous detection systems are currently available, care must be taken in choosing those that are reliable and have proven acceptable levels of sensitivity and specificity, based on adequate laboratory and pre-clinical trial testing.
Volker Gurtler; Charles Pavia
Devices are now available that are practical for point of care testing (PCT) in hospital settings. Previous studies in clinical settings, however, have failed to demonstrate a reduction in patients’ length of stay (LOS) associated with the use of PCT. This randomized controlled study compared PCT with central laboratory testing in a hospital Emergency Department to assess the difference in
Robert P Murray; Michael Leroux; Edward Sabga; Wes Palatnick; Louis Ludwig
Objective To find out how accurately two point of care test systems—CoaguChek Mini and TAS PT-NC (RapidPointCoag)—display international normalised ratios (INRs). Design Comparison of the INRs from the two systems with a \\
Leon Poller; Michelle Keown; Nikhil Chauhan; Armando Tripodi; Caroline Shiach; Jorgen Jespersen
Point-of-care testing is a rapidly growing area in laboratory medicine. Technologies related to point-of-care testing have unique analytical features and are used in a number of clinical applications. These attributes combined with complex regulatory requirements have made point-of-care testing a true specialty within pathology. Manufacturers continue to develop new point-of-care tests and have consolidated multiple assays to single small handheld or bench-top devices. Enterprise hospital-wide data management systems are available to facilitate improved regulatory compliance and transmit test results into the electronic medical record. Some studies have shown that point-of-care testing can improve clinical outcomes or increase the efficiency of hospital operations. In spite of these developments, many challenges remain. In some cases, the quality of point-of-care tests performed by nonlaboratory personnel does not match that of testing performed in the central laboratory. Data management connectivity remains a significant problem, especially for manually performed tests. Managing a point-of-care program to maintain regulatory compliance is also problematic. For these reasons, the future of point-of-care testing is not entirely clear. The most likely scenario will be a slow but progressive growth of point-of-care testing in the hospital, in the outpatient clinic, and in the home. PMID:19840677
One-step lateral flow test is recommended as the first line screening of syphilis for primary healthcare settings in developing countries. However, it generally shows low sensitivity. We describe here the\\u000a development of a novel fluorescent POC (Point Of Care) test method to be used for screening for syphilis. The method was designed\\u000a to combine the rapidness of lateral flow test
Hao Yang; Ding Li; Rong He; Qin Guo; Kan Wang; Xueqing Zhang; Peng Huang; Daxiang Cui
Objective: Major challenges for physicians include selection of effective tests in the time-sensitive identification and management of patients with acute coronary syndromes (ACS). We review whether cardiac marker testing performed at the point-of-care (POC) has an impact on clinical management and guidance of intervention for ACS patients.Design and Methods: Evidence from recently published studies and meta-analyses supports the efficacy of
Hassan M. E Azzazy; Robert H Christenson
Objective To find out how accurately two point of care test systems—CoaguChek Mini and TAS PT-NC (RapidPointCoag)—display international normalised ratios (INRs). Design Comparison of the INRs from the two systems with a “true” INR on a conventional manual test from the same sample of blood. Setting 10 European Concerted Action on Anticoagulation centres. Participants 600 patients on long term dosage of warfarin. Main outcome measures Comparable results between the different methods. Results The mean displayed INR differed by 21.3% between the two point of care test monitoring systems. The INR on one system was 15.2% higher, on average, than the true INR, but on the other system the INR was 7.1% lower. The percentage difference between the mean displayed INR and the true INR at individual centres varied considerably with both systems. Conclusions Improved international sensitivity index calibration of point of care test monitors by their manufacturers is needed, and better methods of quality control of individual instruments by their users are also needed.
Poller, Leon; Keown, Michelle; Chauhan, Nikhil; van den Besselaar, Anton MHP; Tripodi, Armando; Shiach, Caroline; Jespersen, Jorgen
Troponin T has been used successfully to risk stratify patients with acute coronary syndromes, but the utility of this approach using a rapid bedside assay in patients undergoing thrombolysis for ST-segment elevation acute myocardial infarction has not been assessed in a large population. We assessed whether a point-of-care, qualitative troponin T test at enrollment could independently risk-stratify patients randomized to
E. Magnus Ohman; Paul W Armstrong; Harvey D White; Christopher B Granger; Robert G Wilcox; W. Douglas Weaver; W. Brian Gibler; Amanda L Stebbins; Cresha Cianciolo; Robert M Califf; Eric J Topol
Abstract Background: Point-of-care testing (POCT) of blood glucose (BG) is performed by medical personnel in clinical settings as well as by patients themselves for self-monitoring of blood glucose (SMBG) at home. We investigated if a system mainly intended for SMBG by people with diabetes, but also suitable for BG measurements by medical personnel, can achieve measurement accuracy on capillary blood samples comparable with professional-use POCT systems. Methods: System accuracy was evaluated under standardised conditions, following the ISO standard 15197:2003. For each system (one SMBG system with three test strip lots and six professional-use systems), measurement results from capillary blood samples of 100 subjects were compared with a standardised laboratory glucose oxidase method (YSI 2300 glucose analyser). Results: The seven evaluated systems showed 99.5% or 100% of the measurement results within the required system accuracy limits of ISO 15197:2003 (±0.83 mmol/L at BG concentrations <4.2 mmol/L and ±20% at BG concentrations ?4.2 mmol/L). Applying the more stringent requirements of the revision ISO 15197:2013, the systems showed between 99% and 100% of the measurement results within the accuracy limits (±0.83 mmol/L at BG concentrations <5.55 mmol/L and ±15% at BG concentrations ?5.55 mmol/L) and between 82% and 98% when even more restrictive limits were applied (±0.56 mmol/L and ±10%, respectively). Conclusions: Data from this study, which focused on system accuracy, suggest that SMBG systems can achieve system accuracy that is comparable with professional-use systems when measurements are performed on capillary blood samples by trained personnel in a standardised and controlled setting. PMID:24681433
Freckmann, Guido; Schmid, Christina; Pleus, Stefan; Baumstark, Annette; Link, Manuela; Stolberg, Erhard; Haug, Cornelia; Sieber, Jochen
Background The proper development and implementation of point-of-care (POC) diagnostics requires knowledge of the perceived requirements and barriers to their implementation. To determine the current requirements and perceived barriers to the introduction of POC diagnostics in the field of medical microbiology (MM)-POC a prospective online survey (TEMPOtest-QC) was established. Methods and results The TEMPOtest-QC survey was online between February 2011 and July 2012 and targeted the medical community, POC test diagnostic manufacturers, general practitioners, and the general public. In total, 293 individuals responded to the survey, including 91 (31%) medical microbiologists, 39 (13%) nonmedical microbiologists, 25 (9%) employees of POC test manufacturers, and 138 (47%) members of the general public. Responses were received from 18 different European countries, with the largest percentage of these living in The Netherlands (52%). The majority (>50%) of medical specialists regarded the development of MM-POC for blood culture and hospital acquired infections as “absolutely necessary”, but were much less favorable towards their use in the home environment. Significant differences in perceptions between medical specialists and the general public included the: (1) Effect on quality of patient care; (2) Ability to better monitor patients; (3) Home testing and the doctor-patient relationship; and (4) MM-POC interpretation. Only 34.7% of the general public is willing to pay more than a€10 ($13) for a single MM-POC test, with 85.5% preferring to purchase their MM-POC test from a pharmacy. Conclusion The requirements for the proper implementation of MM-POC were found to be generally similar between medical specialists and POC test kit manufacturers. The general public was much more favorable with respect to a perceived improvement in the quality of healthcare that these tests would bring to the hospital and home environment.
Kaman, Wendy E; Andrinopoulou, Eleni-Rosalina; Hays, John P
Rapid evaluation and intervention is a requirement and a characteristic of patient management in neonatal intensive care units, and this applies for equine neonates also. Appropriate interventions are based on solid knowledge of age, maturity, and species-specific differences in reference ranges. Point-of-care (POC) testing devices speedup decision making regarding treatments and interventions. However, there are potential limitations of these devices when applied to age groups and species beyond those they were specifically developed for. This article discusses the age-specific differences in the reference ranges and the potential limitations of POC devices currently used, which may affect delivery of care. PMID:21295726
Wilkins, Pamela A
Many of the diagnostic tests administered in well-funded clinical laboratories are inappropriate for point-of-care testing in low-resource environments. As a result, inexpensive, portable immunoassay tests have been developed to facilitate the rapid diagnosis of many diseases common to developing countries. However, manually analyzing the test results at the point of care may be complex and error-prone for untrained users reading
Nicola Lee Dell; Sugandhan Venkatachalam; Dean Stevens; Paul Yager; Gaetano Borriello
The primary care regularly sees patients that have symptoms that could be due to thromboembolic diseases. It would be valuable to be able to rule out deep venous thrombosis or pulmonary embolism using Wells score and a negative D-dimer testing already at the primary care unit. This requires a validated D-dimer assay suitable for primary care use. We compared D-dimer results obtained with the new point of care analyzer Alere Triage(®) and the central hospital laboratory STA-R Evolution analyzer from the same patient samples (n = 102). We also calculated the total coefficient of variation (CV) for the Alere method. The two methods showed a good linear correlation (R(2) = 0.977) and a slope of 0.975. CV for the Alere D-dimer method was well below 10 %. The study shows that the Alere D-dimer assay and the central laboratory standard assay show similar results. We suggest that the Alere D-dimer assay could be used in primary care in combination with Wells score to reduce referrals to the emergency unit. PMID:24381121
Helmersson-Karlqvist, Johanna; Karlsson, Bo; Fredriksson, Annika; Larsson, Anders
It is now around 30 years since the discovery of HIV, the virus that causes AIDS. More than 70 million people have been infected in that time and around 35 million have died. The majority of those currently living with HIV/AIDS are in low- and middle-income countries, with sub-Saharan Africa bearing a disproportionate burden of the global disease. In high-income countries, the introduction of antiretroviral therapy (ART) has drastically reduced the morbidity and mortality associated with HIV. Patients on ART are now predicted to have near-normal life expectancy and the role of treatment is increasingly recognized in preventing new infections. In low- and middle-income countries, treatment is now more widely available and around half of those who need ART are currently receiving it. Early diagnosis of HIV is essential if ART is to be optimally implemented. Lab-based diagnostics for screening, diagnosis, treatment initiation, and the monitoring of treatment efficacy are critical in managing the disease and reducing the number of new infections each year. The introduction of point-of-care HIV rapid tests has transformed the epidemic, particularly in low- and middle-income countries. For the first time, these point-of-care tests allow for the rapid identification of infected individuals outside the laboratory who can undergo counseling and treatment and, in the case of pregnant women, allow the timely initiation of ART to reduce the risk of vertical transmission. Although survival is markedly improved with ART even in the absence of laboratory monitoring, long-term management of people living with HIV on ART, and their partners, is essential to ensure successful viral suppression. The burden of disease in many resource-poor settings with high HIV prevalence has challenged the ability of local laboratories to effectively monitor those on ART. Diagnostics used to initiate and monitor treatment are now moving out of the laboratory and into the field. These new point-of-care tests for viral load and CD4 are poised to further transform the disease and shift the treatment paradigm in low- and middle-income countries.
Reid, Steven D; Fidler, Sarah J; Cooke, Graham S
Purpose of review Sexually transmitted infections (STIs) remain a major global public health issue, with more than 448 million incident bacterial infections each year. We review recent advances in STI point-of-care (POC) testing and implications for STI prevention and control. Recent findings Accurate immunochromatographic assays to detect HIV, hepatitis C virus (HCV) and syphilis antibodies have made home or supervised self-testing possible. Several studies have demonstrated feasibility and excellent test characteristics for HIV, HCV and syphilis POC tests. Rapid oral HIV tests are now available for purchase at retail sites across the United States. Combined HIV and syphilis tests using a single finger prick blood sample are under evaluation. Summary Oral POC STI tests with comparable performance to blood-based POC tests are available for self-testing. POC tests can expand screening, improve syndromic management and reduce loss to follow up. POC STI tests have the potential to facilitate prompt treatment and partner services. POC STI tests create opportunities for new social and financial models of community-based testing services. Increasing equity and access to testing will create challenges in linkage to care, quality assurance, partner services and surveillance. These important developments warrant research to understand appropriate contexts for implementation.
Tucker, Joseph D.; Bien, Cedric H.; Peeling, Rosanna W.
Analysis of blood coagulation with thrombelastometry (ROTEM™) and thrombelastography (TEG™) and analysis of thrombocyte function by a Multiplate™ assay is possible in only a few hospitals in Germany. Recently, the grade of recommendation (GoR) for point-of-care (POC) testing in official guidelines was increased and is now classified as GoR 1C. If a POC-based option is not available alternatives must be used. Besides blood products (RBC, FFP, TC), coagulation factor concentrates are used to treat trauma-induced coagulopathy. The benefits of therapy with factor concentrates are fewer immunological and infection side effects as well as faster effects after administration of specific coagulation factors. A good outcome in patients with multiple trauma is only possible by an adequate transfusion regime and administration of coagulation factors. PMID:24482058
Lier, H; Hinkelbein, J
Low-cost, robust, and user-friendly diagnostic capabilities at the point-of-care (POC) are critical for treating infectious diseases and preventing their spread in developing countries. Recent advances in micro- and nano-scale technologies have enabled the merger of optical and fluidic technologies (optofluidics) paving the way for cost-effective lensless imaging and diagnosis for POC testing in resource limited settings. Applications of the emerging lensless imaging technologies include detecting and counting cells of interest, which allows rapid and affordable diagnostic decisions. This review presents the advances in lensless imaging and diagnostic systems, and their potential clinical applications in developing countries. The emerging technologies are reviewed from a POC perspective considering cost-effectiveness, portability, sensitivity, throughput and ease of use for resource-limited settings.
Gurkan, Umut Atakan; Moon, Sangjun; Geckil, Hikmet; Xu, Feng; Wang, Shuqi; Lu, Tian Jian; Demirci, Utkan
Objectives Point-of-care (POC) testing for chlamydia (CT) and gonorrhoea (NG) offers a new approach to the diagnosis and management of these sexually transmitted infections (STIs) in remote Australian communities and other similar settings. Diagnosis of STIs in remote communities is typically symptom driven, and for those who are asymptomatic, treatment is generally delayed until specimens can be transported to the reference laboratory, results returned and the patient recalled. The objective of this study was to explore the clinical implications of using CT/NG POC tests in routine clinical care in remote settings. Methods In-depth qualitative interviews were conducted with a purposively selected group of 18 key informants with a range of sexual health and laboratory expertise. Results Participants highlighted the potential impact POC testing would have on different stages of the current STI management pathway in remote Aboriginal communities and how the pathway would change. They identified implications for offering a POC test, specimen collection, conducting the POC test, syndromic management of STIs, pelvic inflammatory disease diagnosis and management, interpretation and delivery of POC results, provision of treatment, contact tracing, management of client flow and wait time, and re-testing at 3 months after infection. Conclusions The introduction of POC testing to improve STI service delivery requires careful consideration of both its advantages and limitations. The findings of this study will inform protocols for the implementation of CT/NG POC testing, and also STI testing and management guidelines.
Natoli, Lisa; Maher, Lisa; Shephard, Mark; Hengel, Belinda; Tangey, Annie; Badman, Steven G.; Ward, James; Guy, Rebecca J.
The Southern states experience the highest rates of HIV and AIDS in the US, and point-of-care (POC) testing outside of primary care may contribute to status awareness in medically underserved populations in this region. To evaluate POC screening and linkage to care at an urban south site, analyses were performed on a dataset of 3,651 individuals from an integrated rapid-result HIV testing and linkage program to describe this test-seeking cohort and determine trends associated with screening, results, and linkage to care. Four percent of the population had positive results. We observed significant differences by test result for age, race and gender, reported risk behaviors, test location, and motivation for screening. The overall linkage rate was 86%, and we found significant differences for clients who were linked to HIV care versus persons whose linkage could not be confirmed with respect to race and gender, location, and motivation. The linkage rate for POC testing that included a comprehensive intake visit and colocated primary care services for in-state residents was 97%. Additional research on integrated POC screening and linkage methodologies that provide intake services at time of testing is essential for increasing status awareness and improving linkage to HIV care in the US.
Dougherty, Sarah M.; Ross-Davis, Kelly L.; Raper, James L.
One-step lateral flow test is recommended as the first line screening of syphilis for primary healthcare settings in developing countries. However, it generally shows low sensitivity. We describe here the development of a novel fluorescent POC (Point Of Care) test method to be used for screening for syphilis. The method was designed to combine the rapidness of lateral flow test and sensitiveness of fluorescent method. 50 syphilis-positive specimens and 50 healthy specimens conformed by Treponema pallidum particle agglutination (TPPA) were tested with Quantum Dot-labeled and colloidal gold-labeled lateral flow test strips, respectively. The results showed that both sensitivity and specificity of the quantum dots-based method reached up to 100% (95% confidence interval [CI], 91-100%), while those of the colloidal gold-based method were 82% (95% CI, 68-91%) and 100% (95% CI, 91-100%), respectively. In addition, the naked-eye detection limit of quantum dot-based method could achieve 2 ng/ml of anti-TP47 polyclonal antibodies purified by affinity chromatography with TP47 antigen, which was tenfold higher than that of colloidal gold-based method. In conclusion, the quantum dots were found to be suitable for labels of lateral flow test strip. Its ease of use, sensitiveness and low cost make it well-suited for population-based on-the-site syphilis screening.
Yang, Hao; Li, Ding; He, Rong; Guo, Qin; Wang, Kan; Zhang, Xueqing; Huang, Peng; Cui, Daxiang
One-step lateral flow test is recommended as the first line screening of syphilis for primary healthcare settings in developing countries. However, it generally shows low sensitivity. We describe here the development of a novel fluorescent POC (Point Of Care) test method to be used for screening for syphilis. The method was designed to combine the rapidness of lateral flow test and sensitiveness of fluorescent method. 50 syphilis-positive specimens and 50 healthy specimens conformed by Treponema pallidum particle agglutination (TPPA) were tested with Quantum Dot-labeled and colloidal gold-labeled lateral flow test strips, respectively. The results showed that both sensitivity and specificity of the quantum dots-based method reached up to 100% (95% confidence interval [CI], 91-100%), while those of the colloidal gold-based method were 82% (95% CI, 68-91%) and 100% (95% CI, 91-100%), respectively. In addition, the naked-eye detection limit of quantum dot-based method could achieve 2 ng/ml of anti-TP47 polyclonal antibodies purified by affinity chromatography with TP47 antigen, which was tenfold higher than that of colloidal gold-based method. In conclusion, the quantum dots were found to be suitable for labels of lateral flow test strip. Its ease of use, sensitiveness and low cost make it well-suited for population-based on-the-site syphilis screening. PMID:20672123
Yang, Hao; Li, Ding; He, Rong; Guo, Qin; Wang, Kan; Zhang, Xueqing; Huang, Peng; Cui, Daxiang
Background Time is a crucial factor in an emergency department and the effectiveness of diagnosing depends on, among other things, the accessibility of rapid reported laboratory test results; i.e.: a short turnaround time (TAT). Former studies have shown a reduced time to action when point of care technologies (POCT) are used in emergency departments. This study assesses the hypothesis, that using Point of Care Technology in analysing blood samples versus tube transporting blood samples for laboratory analyses results in shorter time from the blood sample is collected to the result is reported in an emergency department. Methods The study was designed as a randomised controlled trial with consecutive allocation into two groups and rated 1:1. Blood samples were collected on all included patients and then randomised into either POCT analyses or tube transporting for central laboratory analyses. Results Blood samples from a total of 319 patients were included. The mean time from collecting to reporting was 24 minutes for the POCT analysis and 70 minutes for the tube transported analysis. An unpaired Students t-test showed a significant reduction in time from collecting to reporting using POCT (p<.0001). Conclusion We found a significantly reduced time from collecting to reporting using Point of Care Technology (POCT) in an emergency department compared to tube transported blood samples for central laboratory analyses.
In this paper, we present a low cost and equipment-free blood filtration device capable of producing plasma from blood samples with mL-scale capacity and demonstrate its clinical application for hepatitis B diagnosis. We report the results of in-field testing of the device with 0.8-1?ml of undiluted, anticoagulated human whole blood samples from patients at the National Hospital for Tropical Diseases in Hanoi, Vietnam. Blood cell counts demonstrate that the device is capable of filtering out 99.9% of red and 96.9% of white blood cells, and the plasma collected from the device contains lower red blood cell counts than plasma obtained from a centrifuge. Biochemistry and immunology testing establish the suitability of the device as a sample preparation unit for testing alanine transaminase (ALT), aspartate transaminase (AST), urea, hepatitis B "e" antigen (HBeAg), hepatitis B "e" antibody (HBe Ab), and hepatitis B surface antibody (HBs Ab). The device provides a simple and practical front-end sample processing method for point-of-care microfluidic diagnostics, enabling sufficient volumes for multiplexed downstream tests. PMID:24404044
Gong, Max M; Macdonald, Brendan D; Vu Nguyen, Trung; Van Nguyen, Kinh; Sinton, David
Point-of-care (POC) tests offer potentially substantial benefits for the management of infectious diseases, mainly by shortening the time to result and by making the test available at the bedside or at remote care centres. Commercial POC tests are already widely available for the diagnosis of bacterial and viral infections and for parasitic diseases, including malaria. Infectious diseases specialists and clinical microbiologists should be aware of the indications and limitations of each rapid test, so that they can use them appropriately and correctly interpret their results. The clinical applications and performance of the most relevant and commonly used POC tests are reviewed. Some of these tests exhibit insufficient sensitivity, and should therefore be coupled to confirmatory tests when the results are negative (e.g. Streptococcus pyogenes rapid antigen detection test), whereas the results of others need to be confirmed when positive (e.g. malaria). New molecular-based tests exhibit better sensitivity and specificity than former immunochromatographic assays (e.g. Streptococcus agalactiae detection). In the coming years, further evolution of POC tests may lead to new diagnostic approaches, such as panel testing, targeting not just a single pathogen, but all possible agents suspected in a specific clinical setting. To reach this goal, the development of serology-based and/or molecular-based microarrays/multiplexed tests will be needed. The availability of modern technology and new microfluidic devices will provide clinical microbiologists with the opportunity to be back at the bedside, proposing a large variety of POC tests that will allow quicker diagnosis and improved patient care. PMID:20670287
Clerc, O; Greub, G
Paper-based devices provide an alternative technology for simple, low-cost, portable, and disposable or recyclable diagnostic tools for many applications, including clinical diagnosis, food quality control, and environmental monitoring. The present review focuses on new paper-based tests for point-of-care (POC) infectious disease testing. This review provides a brief presentation of the fabrication techniques and the main sample preparation procedures. Recent immunological and molecular testing formats based on new paper-based solutions which go beyond conventional lateral flow formats are also added. Emphasis is placed on how paper systems could be used for detecting whole and viable bacteria associated to infectious diseases. Paper has recently become attractive, since it is a ubiquitous and extremely cheap material. It is easy to store, easy to use, and is compatible with many (bio)chemical and (bio)medical applications. Paper absorbs and transports liquids by capillary force without additional mechanical assistance. Hence, paper-based analytical devices are promising and possibly game-changing, even if they still suffer from limitations, including accuracy and sensitivity. It is anticipated that, in the near future, with advances in fabrication procedures and associated analytical techniques, there will be a continuous flow of innovative paper-based diagnostics kits. PMID:23982665
Oral anticoagulant (OAC) therapy is usually monitored by noting changes in a tissue factor-induced coagulation time ("prothrombin time") test on whole blood or plasma and expressed as an International Normalized Ratio (INR). Current point-of-care (POC) instruments for monitoring OAC therapy display both the calculated prothrombin time (PT) and the INR. Although many attempts have been made to improve the accuracy and precision of INR determinations in daily practice, it is impossible to eliminate all uncertainty because the PT test is sensitive to multiple factors in the patient's blood specimen. The accuracy of the average INR determined with a POC instrument depends on its calibration against reference methods. Quality control (QC) materials for POC devices are different from patients' samples and may not exactly reflect the real clinical situation. Nevertheless, internal and external QC schemes for POC devices are valuable to investigate their performance in daily practice. Calibration can be improved by direct comparison of a POC system against an established international reference preparation method. In general, the precision of the INR measured with a POC device is slightly lower than the precision achieved with available automated laboratory instruments. The greater imprecision should be weighed against the clinical advantages of a POC testing device. PMID:11711687
van den Besselaar, A M
The limitations of sputum smear microscopy, routine chest radiology for HIV-associated TB and culture-based diagnosis are well recognized, especially in resource-limited settings. The diagnostic accuracy of a new point-of-care lateral-flow urine strip test for lipoarabinomannan (Determine(®) TB-LAM; Alere, MA, USA), which costs US$3.50 per test strip and provides results within 30 min, was evaluated in a cohort of South African patients for HIV-associated TB before starting anti-retroviral therapy in South Africa. Prevalence of culture-positive TB cases was 17.4%, among which 28.2% had sputum smear positivity. Determine(®) TB-LAM (Alere, MA, USA) had highest sensitivity at low CD4 cell counts: 66.7, 51.7 and 39.0% at <50 cells, <100 cells and <200 cells per µl, respectively; specificity was greater than 98% for all strata. There was an incremental sensitivity when Determine TB-LAM was combined with smear microscopy, which did not differ statistically from the sensitivities obtained by testing a single sputum sample with the Xpert(®) MTB/RIF (Cepheid; CA, USA) assay. Determine TB-LAM is a simple, low-cost alternative to existing diagnostic assays for TB screening in HIV-infected patients with very low CD4(+) cell counts. PMID:22568711
Swaminathan, Soumya; Rekha, V V Banu
Various proof-of-concept studies have shown the potential of biosensors with a high multiplex detection capability for the readout of DNA microarrays in a lab-on-a-chip. This is particularly interesting for the development of point-of-care genotyping tests, to screen for multiple pathogens and/or antibiotic resistance patterns. In this paper, an assay workflow is presented, suited for the development of novel lab-on-a-chips with an integrated DNA microarray. Besides the description of the different assay steps (DNA purification, amplification and detection), a control strategy is presented according to recommendations of the US Food and Drug Administration (FDA). To use a lab-on-a-chip for diagnostic applications, the optimization and evaluation of the assay performance with clinical samples is very important. Therefore, appropriate quantification methods are described, which allow optimization and evaluation of the separate assay steps, as well as total assay performance. In order to demonstrate and evaluate the total workflow, blood samples spiked with Streptococcus pneumoniae were tested. All blood samples with ?10(3)CFU S. pneumoniae per ml of human blood were successfully detected by this genotyping assay. PMID:24967749
Van Dorst, Bieke; Cremers, Amelieke; Jans, Karolien; Van Domburg, Trees; Steegen, Kim; Huang, Chengjun; Dorrer, Christian; Lagae, Liesbet; Ferwerda, Gerben; Stuyver, Lieven J
The expansion of HIV antiretroviral therapy into decentralized rural settings will increasingly require simple point-of-care (POC) diagnostic tests that can be used without laboratory infrastructure and technical skills. New POC test devices are becoming available but decisions around which technologies to deploy may be biased without systematic assessment of their suitability for decentralized healthcare settings. To address this, we developed a standardized, quantitative scorecard tool to objectively evaluate the operational characteristics of POC diagnostic devices. The tool scores devices on a scale of 1–5 across 30 weighted characteristics such as ease of use, quality control, electrical requirements, shelf life, portability, cost and service, and provides a cumulative score that ranks products against a set of ideal POC characteristics. The scorecard was tested on 19 devices for POC CD4 T-lymphocyte cell counting, clinical chemistry or hematology testing. Single and multi-parameter devices were assessed in each of test categories. The scores across all devices ranged from 2.78 to 4.40 out of 5. The tool effectively ranked devices within each category (p<0.01) except the CD4 and multi-parameter hematology products. The tool also enabled comparison of different characteristics between products. Agreement across the four scorers for each product was high (intra-class correlation >0.80; p<0.001). Use of this tool enables the systematic evaluation of diagnostic tests to facilitate product selection and investment in appropriate technology. It is particularly relevant for countries and testing programs considering the adoption of new POC diagnostic tests.
Lehe, Jonathan D.; Sitoe, Nadia E.; Tobaiwa, Ocean; Loquiha, Osvaldo; Quevedo, Jorge I.; Peter, Trevor F.; Jani, Ilesh V.
Point-of-care (POC) glucose technology is currently considered to be insufficiently accurate for the diagnosis of diabetes. The objective of this study was to investigate the diagnostic accuracy of an innovative, interference-resistant POC glucose meter (StatStrip glucose hospital meter, Nova Biomedical, USA) in subjects with a previous history of dysglycaemia, undergoing a 75?g diagnostic oral glucose tolerance test (oGTT). Venous and capillary blood sampling for the reference laboratory procedure (RLP) and POC-glucose measurement was carried out at fasting and 2?h oGTT, and categories of glucose tolerance were classified according to 2006 WHO diagnostic criteria for the respective sample type. We found an excellent between-method correlation at fasting (r = 0.9681, P < 0.0001) and 2?h oGTT (r = 0.9768, P < 0.0001) and an almost perfect diagnostic agreement (weighted Kappa?=?0.858). Within a total of 237 study subjects, 137 were diagnosed with diabetes with RLP, and only 6 of them were reclassified as having glucose intolerance with POC. The diagnostic performance of POC-fasting glucose in discriminating between the normal and any category of disturbed glucose tolerance did not differ from the RLP (P = 0.081). Results of this study indicate that StatStrip POC glucose meter could serve as a reliable tool for the diabetes diagnosis, particularly in primary healthcare facilities with dispersed blood sampling services.
Bozicevic, Sandra; Pape-Medvidovic, Edita; Ljubic, Spomenka
Point-of-care (POC) testing is increasingly applied as a cost effective alternative to many diagnostic tests. Key in POC testing is to create sufficient assay sensitivity with relatively low cost reagents and equipment. For this purpose we have employed a unique reporter, upconverting phosphor (UCP) particles, in combination with lateral flow (LF) assays. UCPs, submicron ceramic particles doped with rare earth ions (lanthanides), convert infrared to visible light and do not suffer from autofluorescence which limits conventional fluorescence based assays. Low cost handheld readers and microfluidics were evaluated in various applications. Designed assays are well suited for applications outside diagnostic laboratories, in resource poor settings, and can even be used by patients at home. Using two distinctly different UCP-LF assay formats, we focussed on assays for infectious diseases based on the detection of pathogen-specific antibodies and/or antigens including nucleic acids to demonstrate active infection with HIV. Only minor adaptation of the standard UCP-LF assay format is needed to render the format suitable for applications involving low affinity capture antibodies (e.g. in the detection of neurotoxin, botulism), capture of small molecules (e.g. detection of melatonin, a key hormone in chronopharmacology) or the use of dry UCP reagents (e.g. detection of protein based fruit-ripening markers, of economic interest in agriculture). Finally, we anticipate on developments in healthcare (personalized medicine) by discussing the potential of one of the UCP-LF assay formats to measure serum trough levels of immunodrugs (e.g. infliximab or adalimumab) in patients treated for inflammatory bowel disease and rheumatoid arthritis.
Tanke, Hans J.; Zuiderwijk, Michel; Wiesmeijer, Karien C.; Breedveld, Robert N.; Abrams, William R.; de Dood, Claudia J.; Tjon Kon Fat, Elisa M.; Corstjens, Paul L. A. M.
Introduction Point-of-care testing for CD4 cell count is considered a promising way of reducing the time to eligibility assessment for antiretroviral therapy (ART) and of increasing retention in care prior to treatment initiation. In this review, we assess the available evidence on the patient and programme impact of point-of-care CD4 testing. Methods We searched nine databases and two conference sites (up until 26 October 2013) for studies reporting patient and programme outcomes following the introduction of point-of-care CD4 testing. Where appropriate, results were pooled using random-effects methods. Results Fifteen studies, mainly from sub-Saharan Africa, were included for review, providing evidence for adults, adolescents, children and pregnant women. Compared to conventional laboratory-based testing, point-of-care CD4 testing increased the likelihood of having CD4 measured [odds ratio (OR) 4.1, 95% CI 3.5–4.9, n=2] and receiving a CD4 result (OR 2.8, 95% CI 1.5–5.6, n=6). Time to being tested was significantly reduced, by a median of nine days; time from CD4 testing to receiving the result was reduced by as much as 17 days. Evidence for increased treatment initiation was mixed. Discussion The results of this review suggest that point-of-care CD4 testing can increase retention in care prior to starting treatment and can also reduce time to eligibility assessment, which may result in more eligible patients being initiated on ART.
Wynberg, Elke; Cooke, Graham; Shroufi, Amir; Reid, Steven D; Ford, Nathan
Background and Objective: Almost 50% of military trauma patients who need transfusions develop a coagulopathy. Immediately treating this coagulopathy improves the patient?s prognosis. Field military hospitals often lack laboratory devices needed to diagnose a clinically significant coagulopathy and have limited blood product resources such as plasma. Point-of-care (POC) devices for the measurement of prothrombin time (PT) are available and have been tested in a variety of situations, including hemorrhagic surgery. The authors compared a POC device, the Coaguchek XS Pro (F. Hoffmann-La Roche Ltd., Basel, Switzerland), with laboratory measures for determining the PT in military trauma patients in a field hospital. Methods: This single-center prospective study was designed to compare POC coagulation monitoring with traditional laboratory testing. It was conducted at the French military hospital located at Kabul International Airport. All patients with trauma injuries resulting from war operations were included. A blood sample was drawn immediately on admission. PT was determined both in the laboratory and with use of the Coaguchek XS pro. Results: Forty patients with war trauma were enrolled during a 3-month period. The authors recorded 69 measurements. The two methods were correlated with a correlation coefficient of 0.78 (p < .001). The Bland-Altman plot showed a mean difference of 5.8% (95% confidence interval ?14.9% to 26.6%). Using a PT cutoff of 60%, POC had a sensitivity of 77.1% and a specificity of 94.1%. Results from POC PT measurement were available within a mean of 25.8 minutes before laboratory measures. Conclusions: The Coaguchek XS Pro device can be used successfully in an austere environment without compromising its performance. PMID:24227563
Cotte, Jean; D'Aanda, Erwan; Chauvin, Vincent; Kaiser, Eric; Meaudre, Eric
Background Poor adherence to isoniazid (INH) preventive therapy (IPT) is an impediment to effective control of latent tuberculosis (TB) infection. TB patients who smoke are at higher risk of latent TB infection, active disease, and TB mortality, and may have lower adherence to their TB medications. The objective of our study was to validate IsoScreen and SmokeScreen (GFC Diagnostics, UK), two point-of-care tests for monitoring INH intake and determining smoking status. The tests could be used together in the same individual to help identify patients with a high-risk profile and provide a tailored treatment plan that includes medication management, adherence interventions, and smoking cessation programs. Methodology/Principal Findings 200 adult outpatients attending the TB and/or the smoking cessation clinic were recruited at the Montreal Chest Institute. Sensitivity and specificity were measured for each test against the corresponding composite reference standard. Test reliability was measured using kappa statistic for intra-rater and inter-rater agreement. Univariate and multivariate logistic regression models were used to explore possible covariates that might be related to false-positive and false-negative test results. IsoScreen had a sensitivity of 93.2% (95% confidence interval [CI] 80.3, 98.2) and specificity of 98.7% (94.8, 99.8). IsoScreen had intra-rater agreement (kappa) of 0.75 (0.48, 0.94) and inter-rater agreement of 0.61 (0.27, 0.90). SmokeScreen had a sensitivity of 69.2% (56.4, 79.8), specificity of 81.6% (73.0, 88.0), intra-rater agreement of 0.77 (0.56, 0.94), and inter-rater agreement of 0.66 (0.42, 0.88). False-positive SmokeScreen tests were strongly associated with INH treatment. Conclusions IsoScreen had high validity and reliability, whereas SmokeScreen had modest validity and reliability. SmokeScreen tests did not perform well in a population receiving INH due to the association between INH treatment and false-positive SmokeScreen test results. Development of the next generation SmokeScreen assay should account for this potential interference.
Nicolau, Ioana; Tian, Lulu; Menzies, Dick; Ostiguy, Gaston; Pai, Madhukar
The U.S. Institute of Medicine (IOM) much publicized report in “To Err is Human” (2000, National Academy Press) stated that as many as 98 000 hospitalized patients in the U.S. die each year due to preventable medical errors. This revelation about medical error and patient safety focused the public and the medical community's attention on errors in healthcare delivery including laboratory and point-of-care-testing (POCT). Errors introduced anywhere in the POCT process clearly can impact quality and place patient's safety at risk. While POCT performed by or near the patient reduces the potential of some errors, the process presents many challenges to quality with its multiple tests sites, test menus, testing devices and non-laboratory analysts, who often have little understanding of quality testing. Incoherent or no regulations and the rapid availability of test results for immediate clinical intervention can further amplify errors. System planning and management of the entire POCT process are essential to reduce errors and improve quality and patient safety.
Ehrmeyer, Sharon S.
ObjectiveA goal-directed therapy algorithm based on serial lactate values obtained from a point-of-care testing device was utilized in an attempt to reduce the mortality of patients after congenital heart surgery.DesignProspective study of patients undergoing surgery utilizing a goal-directed therapy algorithm in the postoperative period. The results of this group are compared with a historical cohort. Operative risk was determined using
Anthony F. Rossi; Danyal M. Khan; Robert Hannan; Juan Bolivar; Michel Zaidenweber; Redmond Burke
The design of a novel therapeutic drug monitoring (TDM) point-of-care-testing (POCT) biochip for immunosuppressants detection in transplanted patients is described. The chip consists of two polymeric parts, a top PMMA slide and a bottom ZEONOR® thin foil, bonded together by means of a pressure sensitive adhesive tape. The tape, with lower refractive index, is shaped in order to obtain a microfluidic multi-channel array. The optical signal, coming from an external light source and travelling along the ZEONOR® thin foil, excites the fluorescent sensing layer immobilized onto the fluidic channels. Preliminary tests with the bioassay implementation for tacrolimus detection are reported.
Berrettoni, C.; Trono, C.; Berneschi, S.; Giannetti, A.; Tombelli, S.; Bernini, R.; Grimaldi, A.; Persichetti, G.; Testa, G.; Bolzoni, L.; Porro, G.; Becker, H.; Gärtner, C.; Baldini, F.
Background and Aims: When dealing with very sick patients, the speed and accuracy of tests to detect metabolic derangements is very important. We evaluated if there was agreement between whole blood electrolytes measured by a point-of-care device and serum electrolytes measured using indirect ion-selective electrodes. Materials and Methods: In this prospective study, electrolytes were analyzed in 44 paired samples drawn from critically ill patients. Whole blood electrolytes were analyzed using a point-of-care blood gas analyzer and serum electrolytes were analyzed in the central laboratory on samples transported through a rapid transit pneumatic system. Agreement was summarized by the mean difference with 95% limits of agreement (LOA) and Lin’s concordance correlation (p c). Results: There was a significant difference in the mean (±standard deviation) sodium value between whole blood and serum samples (135.8 ± 5.7 mmol/L vs. 139.9 ± 5.4 mmol/L, P < 0.001), with the agreement being modest (pc = 0.71; mean difference ?4.0; 95% LOA ?8.78 to 0.65). Although the agreement between whole blood and serum potassium was good (pc = 0.96), and the average difference small (?0.3; 95% LOA ?0.72 to 0.13), individual differences were clinically significant, particularly at lower potassium values. For potassium values <3.0 mmol/L, the concordance was low (pc = 0.53) and the LOA was wide (1.0 to ?0.13). The concordance for potassium was good (pc = 0.96) for values ?3.0 (mean difference ?0.2; 95% LOA ?0.48 to 0.06). Conclusions: Clinicians should be aware of the difference between whole blood and serum electrolytes, particularly when urgent samples are tested at point of care and routine follow-up electrolytes are sent to the central laboratory. A correction factor needs to be determined at each center.
Chacko, Binila; Peter, John V; Patole, Shalom; Fleming, Jude J; Selvakumar, Ratnasamy
In developed nations, monitoring for drug-induced liver injury via serial measurements of serum transaminases (aspartate aminotransferase (AST) and alanine aminotransferase (ALT)) in at-risk individuals is the standard of care. Despite the need, monitoring for drug-related hepatotoxicity in resource-limited settings is often limited by expense and logistics, even for patients at highest risk. This manuscript describes the development and clinical testing of a paper-based, multiplexed microfluidic assay designed for rapid, semi-quantitative measurement of AST and ALT in a fingerstick specimen. Using 223 clinical specimens obtained by venipuncture and 10 fingerstick specimens from healthy volunteers, we have shown that our assay can, in 15 minutes, provide visual measurements of AST and ALT in whole blood or serum which allow the user to place those values into one of three readout “bins” (<3x upper limit of normal (ULN), 3-5x ULN, and >5x ULN, corresponding to tuberculosis/HIV treatment guidelines) with >90% accuracy. These data suggest that the ultimate point-of-care fingerstick device will have high impact on patient care in low-resource settings.
Pollock, Nira R.; Rolland, Jason P.; Kumar, Shailendra; Beattie, Patrick D.; Jain, Sidhartha; Noubary, Farzad; Wong, Vicki L.; Pohlmann, Rebecca A.; Ryan, Una S.; Whitesides, George M.
Medical errors are a major concern in health care today. Errors in point-of-care testing (POCT) are particularly problematic because the test is conducted by clinical operators at the site of patient care and immediate medical action is taken on the results prior to review by the laboratory. The Performance Improvement Program at Baystate Health System, Springfield, Massachusetts, noted a number of identification errors occurring with glucose and blood gas POCT devices. Incorrect patient account numbers that were attached to POCT results prevented the results from being transmitted to the patient's medical record and appropriately billed. In the worst case, they could lead to results being transferred to the wrong patient's chart and inappropriate medical treatment. Our first action was to lock-out operators who repeatedly made identification errors (3-Strike Rule), requiring operators to be counseled and retrained after their third error. The 3-Strike Rule significantly decreased our glucose meter errors (p = 0.014) but did not have an impact on the rate of our blood gas errors (p = 0.378). Neither device approached our ultimate goal of zero tolerance. A Failure Mode and Effects Analysis (FMEA) was conducted to determine the various processes that could lead to an identification error. A primary source of system failure was the manual entry of 14 digits for each test, five numbers for operator and nine numbers for patient account identification. Patient barcoding was implemented to automate the data entry process, and after an initial familiarization period, resulted in significant improvements in error rates for both the glucose (p = 0.0007) and blood gas devices (p = 0.048). Despite the improvements, error rates with barcoding still did not achieve zero errors. Operators continued to utilize manual data entry when the barcode scan was unsuccessful or unavailable, and some patients were found to have incorrect patient account numbers due to hospital transfer, multiple wristbands on a single patient, and selection of expired account numbers from previous hospitalizations when printing the barcoded wristbands. Barcoding can thus improve the incidence of identification errors, but hospitals need to take additional steps to ensure successful barcode scanning and to verify that patient wristbands contain correct information. Implementation of patient barcoding was successful in significantly reducing identification errors with POCT, improving patient care, and enhancing interdisciplinary communication. PMID:15597554
Nichols, James H; Bartholomew, Cathy; Brunton, Mary; Cintron, Carlos; Elliott, Sheila; McGirr, Joan; Morsi, Deborah; Scott, Sue; Seipel, Joseph; Sinha, Daisy
Background Current laboratory and point-of-care tests for HIV detect different analytes and use different sample types. Some have fast turnaround times (<1 hour). We investigated how HIV test choice could impact case finding by testing programs. Methods We analyzed 21,234 consecutive HIV tests with venous blood obtained by San Francisco HIV testing programs from 2003 to 2008. For a subset, oral fluid (n?=?6446) or fingerstick blood (n?=?8127) samples were also obtained for rapid testing. In all cases, HIV status was determined using an HIV antibody-plus-RNA test algorithm. We assessed how the screening antibody tests performed individually versus the gold standard of the full algorithm. We then evaluated the potential ability of other tests (including new tests) to detect more cases, by re-testing all specimens that had negative/discrepant antibody results on initial screening. Findings The antibody-RNA algorithm identified 58 acute and 703 established HIV infection cases. 1st-generation (Vironostika) and 3rd-generation (Genetic Systems) immunoassays had 92 and 96 percent sensitivity, respectively. The Oraquick rapid test had clinical sensitivity of only 86 percent on oral fluid samples, but 92 percent on finger-stick blood. Newer 4th-generation, antigen-antibody combo rapid immunoassay (ARCHITECT) detected HIV in 87 percent of all the acute cases that had been missed by one of the previous screening assays. A point-of-care 4th generation antigen-antibody combo rapid test (Determine) detected about 54 percent of such acute cases. Conclusions Our study suggests that some rapid antibody blood tests will give similar case detection to laboratory antibody tests, but that oral fluid testing greatly reduces ability to detect HIV. New 4th-generation combo tests can detect the majority of acute infections detectable by HIV RNA but with rapid results. Using these tests as a primary screening assay in high-risk HIV testing programs could reduce or eliminate the need for HIV RNA testing.
Pilcher, Christopher D.; Louie, Brian; Facente, Shelley; Keating, Sheila; Hackett, John; Vallari, Ana; Hall, Chris; Dowling, Teri; Busch, Michael P.; Klausner, Jeffrey D.; Hecht, Frederick M.; Liska, Sally; Pandori, Mark W.
In recent years, there has been significant investment from both the private and public sectors in the development of diagnostic technologies to meet the need for human immunodeficiency virus (HIV) and tuberculosis testing in low-resource settings. Future investments should ensure that the most appropriate technologies are adopted in settings where they will have a sustainable impact. Achieving these aims requires the involvement of many stakeholders, as their needs, operational constraints, and priorities are often distinct. Here, we discuss these considerations from different perspectives representing those of various stakeholders involved in the development, introduction, and implementation of diagnostic tests. We also discuss some opportunities to address these considerations.
Palamountain, Kara M.; Baker, Jeff; Cowan, Elliot P.; Essajee, Shaffiq; Mazzola, Laura T.; Metzler, Mutsumi; Schito, Marco; Stevens, Wendy S.; Young, Gloria J.
Background. The Centers for Disease Control and Prevention (CDC) recommends testing and linkage to care for persons most likely infected with hepatitis C virus (HCV), including persons with human immunodeficiency virus. We explored facilitators and barriers to integrating HCV point-of-care (POC) testing into standard operations at an urban STD clinic. Methods. The OraQuick HCV rapid antibody test was integrated at the Denver Metro Health Clinic (DMHC). All clients with at least one risk factor were offered the POC test. Research staff conducted interviews with clients (three HCV positive and nine HCV negative). Focus groups were conducted with triage staff, providers, and linkage-to-care counselors. Results. Clients were pleased with the ease of use and rapid return of results from the HCV POC test. Integrating the test into this setting required more time but was not overly burdensome. While counseling messages were clear to staff, clients retained little knowledge of hepatitis C infection or factors related to risk. Barriers to integrating the HCV POC test into clinic operations were loss to follow-up and access to care. Conclusion. DMHC successfully integrated HCV POC testing and piloted a HCV linkage-to-care program. Providing testing opportunities at STD clinics could increase identification of persons with HCV infection.
Jewett, A.; Al-Tayyib, A. A.; Ginnett, L.; Smith, B. D.
PurposeWe assessed sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the bladder tumor antigen (Bard BTA**Bard Canada Inc., Missisauga, Ontario, Canada.), fibrinogen\\/fibrin degradation products (AuraTek FDP††PerImmune Inc., Rockville, Maryland.), urinary cytology and hemoglobin dipstick tests in the urine of patients presenting to a urology clinic.
Brenda Johnston; Alvaro Morales; Laurel Emerson; Mark Lundie
Background: Delays in receipt of positive HIV test results and in entry into HIV care are common problems in clinics; in public venues, up to 33% of patients with negative results and 25% of those with positive results never learn their results. Methods: Patients aged 18 years or older at an urban sexually transmitted disease (STD) clinic were offered rapid
Sabrina R. Kendrick; Karen A. Kroc; David Withum; Robert J. Rydman; Bernard M. Branson; Robert A. Weinstein
Background Neonates routinely receive vitamin K to prevent vitamin K deficiency bleeding, which is associated with a high mortality rate and a high frequency of neurological sequelae. A coagulation screening test might be necessary to detect prophylactic failure or incomplete prophylaxis. However, venous access and the volume of blood required for such testing can be problematic. CoaguChek XS is a portable device designed to monitor prothrombin time while only drawing a small volume of blood. Although the device is used in adults and children, studies have not been performed to evaluate its clinical utility in neonates, and the reference value is unknown in this population. The objectives of the present study were to determine the reference intervals (RIs) for international normalized ratio (INR) using the CoaguChek XS by capillary puncture in healthy term neonates, to evaluate factors that correlate with INR, and to evaluate the device by assessing its ease of use in clinical practice. Methods This study included 488 healthy term neonates born at a perinatal center between July 2012 and June 2013. The INRs determined by CoaguChek XS were measured in 4-day-old neonates. Results The enrolled neonates were orally administered vitamin K 6-12 h after birth. A RI for INRs in 4-day-old neonates was established using the CoaguChek XS with a median value of 1.10 and a range of 0.90–1.30. A significant difference in the INR was noted between male (median value, 1.10; RI, 0.90–1.30) and female (median value, 1.10; RI, 0.90–1.24) neonates (p?=?0.049). The INR was found to correlate with gestational age, birth weight, and hematocrit value. Conclusions The CoaguChek XS device is safe, fast, and convenient for performing INR assays in neonates. Our study is the first to establish a RI for INRs that were measured using the CoaguChek XS in healthy term neonates.
As the world prepares for the next influenza pandemic, governments have made significant funding commitments to vaccine development and antiviral stockpiling. While these are essential components to pandemic response, rapid and accurate diagnostic testing remains an often neglected cornerstone of pandemic influenza preparedness. Clinicians and Public Health Practitioners need to understand the benefits and drawbacks of different influenza tests in both seasonal and pandemic settings. Culture has been the traditional gold standard for influenza diagnosis but requires from 1-10 days to generate a positive result, compared to nucleic acid detection methods such as real time reverse transcriptase polymerase chain reaction (RT-PCR). Although the currently available rapid antigen detection kits can generate results in less than 30 minutes, their sensitivity is suboptimal and they are not recommended for the detection of novel influenza viruses. Until point-of-care (POC) tests are improved, PILPN recommends that the best option for pandemic influenza preparation is the enhancement of nucleic acid-based testing capabilities across Canada. PMID:19507723
Hatchette, Todd F; Bastien, Nathalie; Berry, Jody; Booth, Tim F; Chernesky, Max; Couillard, Michel; Drews, Steven; Ebsworth, Anthony; Fearon, Margaret; Fonseca, Kevin; Fox, Julie; Gagnon, Jean-Nicolas; Guercio, Steven; Horsman, Greg; Jorowski, Cathy; Kuschak, Theodore; Li, Yan; Majury, Anna; Petric, Martin; Ratnam, Sam; Smieja, Marek; Van Caeseele, Paul
Objectives To determine the prevalence and correlates of syphilis among pregnant women in rural areas of South China. Methods Point-of-care syphilis testing was provided at 71 health facilities in less developed, rural areas of Guangdong Province. Positive samples were confirmed at a local referral center by toluidine red unheated serum tests (TRUST) and Treponema pallidum particle agglutination (TPPA) tests. Results Altogether 27,150 pregnant women in rural Guangdong were screened for syphilis. 106 (0.39%) syphilis cases were diagnosed, of which 78 (73.6%) received treatment for syphilis. Multivariate analysis revealed that older pregnant women (31–35 years old, aOR 2.7, 95% CI 0.99–7.32; older than 35 years old, aOR 5.9, 95% CI 2.13–16.34) and those with a history of adverse pregnant outcomes (aOR 3.64, 95% CI 2.30–5.76) were more likely to be infected with syphilis. Conclusions A high prevalence of syphilis exists among pregnant women living in rural areas of South China. Enhanced integration of syphilis screening with other routine women's health services (OB GYN, family planning) may be useful for controlling China's syphilis epidemic.
Yang, Li-Gang; Tucker, Joseph D.; Liu, Feng-Ying; Ren, Xu-Qi; Hong, Xuan; Wang, Cheng; McLaughlin, Megan M.; Bien, Cedric H.; Chen, Xiang-Sheng; Yang, Bin
Rapid progress has been made in the development of new diagnostic assays for tuberculosis in recent years. New technologies have been developed and assessed, and are now being implemented. The Xpert MTB/RIF assay, which enables simultaneous detection of Mycobacterium tuberculosis (MTB) and rifampicin (RIF) resistance, was endorsed by WHO in December, 2010. This assay was specifically recommended for use as the initial diagnostic test for suspected drug-resistant or HIV-associated pulmonary tuberculosis. By June, 2012, two-thirds of countries with a high tuberculosis burden and half of countries with a high multidrug-resistant tuberculosis burden had incorporated the assay into their national tuberculosis programme guidelines. Although the development of the Xpert MTB/RIF assay is undoubtedly a landmark event, clinical and programmatic effects and cost-effectiveness remain to be defined. We review the rapidly growing body of scientific literature and discuss the advantages and challenges of using the Xpert MTB/RIF assay in areas where tuberculosis is endemic. We also review other prospects within the developmental pipeline. A rapid, accurate point-of-care diagnostic test that is affordable and can be readily implemented is urgently needed. Investment in the tuberculosis diagnostics pipeline should remain a major priority for funders and researchers. PMID:23531388
Lawn, Stephen D; Mwaba, Peter; Bates, Matthew; Piatek, Amy; Alexander, Heather; Marais, Ben J; Cuevas, Luis E; McHugh, Timothy D; Zijenah, Lynn; Kapata, Nathan; Abubakar, Ibrahim; McNerney, Ruth; Hoelscher, Michael; Memish, Ziad A; Migliori, Giovanni Battista; Kim, Peter; Maeurer, Markus; Schito, Marco; Zumla, Alimuddin
Background. Point-of-care (POC) diagnostics for syphilis can contribute to epidemic control by offering a timely knowledge of serostatus. Although accuracy data on POC syphilis tests have been widely published, few studies have evaluated broader outcomes beyond accuracy that impact patients and health systems. We comprehensively reviewed evidence and reporting of these implementation research outcomes (IROs), and proposed a framework to improve their quality. Methods. Three reviewers systematically searched 6 electronic databases from 1980 to 2014 for syphilis POC studies reporting IROs. Data were abstracted and findings synthesised narratively. Results. Of 71 studies identified, 38 documented IROs. IROs were subclassified into preference (7), acceptability (15), feasibility (15), barriers and challenges (15), impact (13), and prevalence (23). Using our framework and definitions, a pattern of incomplete documentation, inconsistent definitions, and lack of clarity was identified across all IROs. Conclusion. Although POC screening tests for syphilis were generally favourably evaluated across a range of outcomes, the quality of evidence was compromised by inconsistent definitions, poor methodology, and documentation of outcomes. A framework for standardized reporting of outcomes beyond accuracy was proposed and considered a necessary first step towards an effective implementation of these metrics in POC diagnostics research.
Jafari, Yalda; Joseph, Lawrence; Vadnais, Caroline; Pant Pai, Nitika
There is currently great need for high-quality, low-cost, point-of-care diagnostics that can benefit patients in resource-limited settings, and correspondingly growing interest in the diagnostic utility of microfluidic platforms based on paper. We describe the development, early clinical testing, and potential clinical impact of a novel paper-based, multiplexed microfluidic assay designed for rapid, semi-quantitative measurement of AST and ALT in a fingerstick specimen. This device ultimately holds promise for providing universal access to affordable point-of-care screening for drug-induced liver injury in resource-limited settings, and opens the door to development of similar point-of-care clinical assays for other important analytes.
Pollock, Nira R.; Colby, Donn; Rolland, Jason P.
Our study objective was to assess economic and clin ical outcomes of use of a point-of-care (POC) blood analy sis device for postoperative coronary artery bypass graft (CABG) patients. A decision analytic model was devel oped for patients with high expected use of blood analy sis, high potential benefit from rapid turn around time of results, a large annual volume
Michael T. Halpern; Cynthia S. Palmer; Kit N. Simpson; Francis D. Chesley; Bryan R. Luce; Johan P. Suyderhoud; Bonnie V. Neibauer; Fawzy G. Estafanous
Background Gastro-enteritis is associated with significant morbidity and mortality in patients with HIV/AIDS and children, and Cryptosporidium is the most important parasite implicated. To date, several commercial companies have developed simple and rapid point-of-care tests for the detection of Cryptosporidium infection; however, information is scarce regarding their diagnostic significance in Ethiopia. This study aimed at evaluating the performance of a rapid diagnostic test (RDT) for the detection of Cryptosporidium stool antigen. Methods A hospital-based cross-sectional study was conducted in Hawassa University Hospital, southern Ethiopia from May to November 2013. Faecal samples were collected from a total of 100 children and 250 HIV infected individuals with diarrhea or CD4 T-cell count lower than 200 cells/?l. Specimens were processed using direct, formol-ether concentration and modified Ziehl-Neelsen techniques for diagnosis of Cryptosporidium and other parasites. One hundred faecal samples (50 positives for Cryptosporidium, 35 positives for other parasites and 15 negatives for any intestinal parasites) were tested using the CoproStrip™Cryptosporidium kit (Savyon Diagnostics Ltd, Israel). Test parameters were calculated using microscopy of the modified Ziehl-Neelsen stained stool smear as reference method. Results The performance of the RDT was first compared to routine microscopic analysis (examination ?10 min). The CoproStrip™Cryptosporidium RDT correctly detected 31 of 42 positive samples and 49 of 50 negative samples (i.e., 11 false negatives and 1 false positive). Sensitivity, specificity, PPV, NPV and accuracy were calculated to be 74, 98, 97, 84 and 88%, respectively. Upon thorough microscopic analysis (examination >10 min), 8 more samples with very low oocyst density were found. However, these were missed by the kit and lower the sensitivity and NPV to 62 and 72%, respectively. No cross-reactivity was observed with any of the helminthic or other protozoan parasites including Isospora and Cyclospora species. Conclusion Based on the results described herein, the CoproStrip™Cryptosporidium test could be used as an alternative to conventional microscopy especially where diagnosis of Cryptosporidium is limited due to time constraints, lack of experienced microscopists or unavailability of appropriate equipment/electricity.
Background. We evaluated whether a pilot program providing point-of-care (POC), but not rapid, CD4 testing (BD FACSCount) immediately after testing HIV-positive improved retention in care. Methods. We conducted a retrospective record review at the Themba Lethu Clinic in Johannesburg, South Africa. We compared all walk-in patients testing HIV-positive during February, July 2010 (pilot POC period) to patients testing positive during January 2008–February 2009 (baseline period). The outcome for those with a ?250 cells/mm3 when testing HIV-positive was initiating ART <16 weeks after HIV testing. Results. 771 patients had CD4 results from the day of HIV testing (421 pilots, 350 baselines). ART initiation within 16 weeks was 49% in the pilot period and 46% in the baseline period. While all 421 patients during the pilot period should have been offered the POC test, patient records indicate that only 73% of them were actually offered it, and among these patients only 63% accepted the offer. Conclusions. Offering CD4 testing using a point-of-care, but not rapid, technology and without other health system changes had minor impacts on the uptake of HIV care and treatment. Point-of-care technologies alone may not be enough to improve linkage to care and treatment after HIV testing.
Larson, Bruce A.; Long, Lawrence; Xulu, Thembi; Sanne, Ian; Fox, Matthew P.
This paper reviews 14 published studies describing performance characteristics, including sensitivity and specificity, of commercially available rapid, point-of-care (POC) influenza tests in patients affected by an outbreak of a novel swine-related influenza A (H1N1) that was declared a pandemic in 2009. Although these POC tests were not intended to be specific for this pandemic influenza strain, the nonspecialized skills required
Steven M. Babin; Yu-Hsiang Hsieh; Richard E. Rothman; Charlotte A. Gaydos
We evaluated the analytical performance of the i-STAT Portable Clinical Analyzer (PCA), a point- of-care testing system consisting of a hand-held analyzer and single-use cartridges that measure different panels of electrolytes, metabolites, blood gases, and hematocrit in 65-100 µl of blood. Our objective was to determine whether PCA measurements at the bedside of patients in the neonatal and pediatric intensive
Christine Papadea; Joyce Foster; Sharon Grant; Sandra A. Ballard; John C. Cate; W. Michael
Point-of-care (POC) coagulometers are increasingly used by patients for self-monitoring of oral vitamin K antagonists therapy.\\u000a We studied the feasibility of introducing POC international normalised ratio (INR) testing in place of standard laboratory\\u000a assays in a hospital-based anticoagulation clinic with 250 active patients. The CoaguChek® XS system was first validated in\\u000a 253 INR samples and found to have a correlation
Ming Chai Kong; Teong Guan Lim; Heng Joo Ng; Yiong Huak Chan; Lai Heng Lee
There are no comprehensive studies on the performance of commonly used point-of-care diagnostic enzyme immunoassay for common arthropod-borne canine pathogens. A comparative evaluation of an immunochromatographic test for these infections with a comprehensive polymerase chain reaction (PCR) test panel was performed on 100 pet dogs and 100 stray dogs without obvious clinical symptoms. Of the 162 positive test results from both immunochromatographic test and PCR, there was 85.2% concordance. The 24 discordant results between serology and PCR occurred in tests involving Ehrlichia canis (14) and Anaplasma platys (10), which may be related to the time of infection. No positive cases of borreliosis or rickettsiosis were detected. One important limitation of the immunochromatographic test was its lack of testing for babesiosis and hepatozoonosis. The former is the most prevalent arthropod-borne canine infection in our cohort (41%). Coinfections were found in 19% stray dogs and 6% of pet dogs with both tests (p < 0.01). Seventeen and 8 samples from stray and pet dogs, respectively, were initially positive in the PCR test for Ehrlichia. However, on sequencing of the PCR amplicon, 10 from stray and 2 from pet dogs were found to be Wolbachia sequences instead, with 100% nucleotide identity to the 16S rRNA sequence of Wolbachia endosymbiont of Dirofilaria immitis. The presence of Wolbachia DNAemia (6%) correlated well with the molecular test and immunochromatographic antigen test for D. immitis. PMID:21612526
Wong, Samson S Y; Teng, Jade L L; Poon, Rosana W S; Choi, Garnet K Y; Chan, Kwok-Hung; Yeung, Michelle L; Hui, Janet J Y; Yuen, Kwok-Yung
Background Determine HIV Combo (DHC) is the first point of care assay designed to increase sensitivity in early infection by detecting both HIV antibody and antigen. We conducted a large multi-centre evaluation of DHC performance in Sydney sexual health clinics. Methods We compared DHC performance (overall, by test component and in early infection) with conventional laboratory HIV serology (fourth generation screening immunoassay, supplementary HIV antibody, p24 antigen and Western blot tests) when testing gay and bisexual men attending four clinic sites. Early infection was defined as either acute or recent HIV infection acquired within the last six months. Results Of 3,190 evaluation specimens, 39 were confirmed as HIV-positive (12 with early infection) and 3,133 were HIV-negative by reference testing. DHC sensitivity was 87.2% overall and 94.4% and 0% for the antibody and antigen components, respectively. Sensitivity in early infection was 66.7% (all DHC antibody reactive) and the DHC antigen component detected none of nine HIV p24 antigen positive specimens. Median HIV RNA was higher in false negative than true positive cases (238,025 vs. 37,591 copies/ml; p?=?0.022). Specificity overall was 99.4% with the antigen component contributing to 33% of false positives. Conclusions The DHC antibody component detected two thirds of those with early infection, while the DHC antigen component did not enhance performance during point of care HIV testing in a high risk clinic-based population.
Conway, Damian P.; Holt, Martin; McNulty, Anna; Couldwell, Deborah L.; Smith, Don E.; Davies, Stephen C.; Cunningham, Philip; Keen, Phillip; Guy, Rebecca
A new sample-to-answer polymer lab-on-a-chip, which can perform immunoassay with minimum user intervention through on-chip reservoirs for reagents and single-channel assay system, has been designed, developed and successfully characterized as a point-of-care testing (POCT) cartridge for the detection of thyroid stimulating hormone (TSH). Test results were obtained within 30 minutes after a sample was dropped into the POCT cartridge. The analyzed results of TSH showed a linear range of up to 55 ?IU mL(-1) with the limit of detection (LOD) of 1.9 ?IU mL(-1) at the signal-to-noise ratio (SNR) of 3. The reagents stored in the on-chip reservoirs maintained more than 97% of their initial volume for 120 days of storage time while the detection antibody retained its activity above 98% for 120 days. The sample-to-answer polymer lab-on-a-chip developed in this work using the mass-producible and low-cost polymer is well suited for the point-of-care testing of rapid in vitro diagnostics (IVD) of TSH. PMID:24121997
Jung, Wooseok; Han, Jungyoup; Kai, Junhai; Lim, Ji-Youn; Sul, Donggeun; Ahn, Chong H
In this paper, a pen-on-paper electrochemiluminescence (PoP-ECL) device was entirely hand drawn and written in commercially available crayon and pencil in turn for the first time, and a constant potential-triggered sandwich-type immunosensor was introduced into the PoP-ECL device to form a low-cost ECL immunodevice proof. Each PoP-ECL device contained a hydrophilic paper channel and two PoP electrodes, and the PoP-ECL device was produced as follows: crayon was firstly used to draw hydrophobic regions on pure cellulose paper to create the hydrophilic paper channels followed with a baking treatment, and then a 6B-type black pencil with low resistivity was applied for precision writing, as the PoP electrodes, across the hydrophilic paper channel. For further point-of-care testing, a portable, low-cost rechargeable battery was employed as the power source to provide constant potential to the PoP electrodes to trigger the ECL. Using Carbohydrate antigen 199 as model analyte, this PoP-ECL immunodevice showed a good linear response range from 0.01-200UmL(-1) with a detection limit of 0.0055UmL(-1), a high sensitivity and stability. The proposed PoP-ECL immunodevice could be used in point-of-care testing of other tumor markers for remote regions and developing countries. PMID:24841090
Yang, Hongmei; Kong, Qingkun; Wang, Shaowei; Xu, Jinmeng; Bian, Zhaoquan; Zheng, Xiaoxiao; Ma, Chao; Ge, Shenguang; Yu, Jinghua
Purpose To identify factors that determine patients’ intentions to use point-of-care medical devices, ie, portable coagulometer devices for self-testing of the international normalized ratio (INR) required for ongoing monitoring of blood-coagulation intensity among patients on long-term oral anticoagulation therapy with vitamin K antagonists, eg, warfarin. Methods A cross-sectional study that applied the technology-acceptance model through a self-completed questionnaire, which was administered to a convenience sample of 125 outpatients attending outpatient anticoagulation services at a district general hospital in London, UK. Data were analyzed using descriptive statistics, factor analyses, and structural equation modeling. Results The participants were mainly male (64%) and aged ? 71 years (60%). All these patients were attending the hospital outpatient anticoagulation clinic for INR testing; only two patients were currently using INR self-testing, 84% of patients had no knowledge about INR self-testing using a portable coagulometer device, and 96% of patients were never offered the option of the INR self-testing. A significant structural equation model explaining 79% of the variance in patients’ intentions to use INR self-testing was observed. The significant predictors that directly affected patients’ intention to use INR self-testing were the perception of technology (? = 0.92, P < 0.001), trust in doctor (? = ?0.24, P = 0.028), and affordability (? = 0.15, P = 0.016). In addition, the perception of technology was significantly affected by trust in doctor (? = 0.43, P = 0.002), age (? = ?0.32, P < 0.001), and affordability (? = 0.23, P = 0.013); thereby, the intention to use INR self-testing was indirectly affected by trust in doctor (? = 0.40), age (? = ?0.29), and affordability (? = 0.21) via the perception of technology. Conclusion Patients’ intentions to use portable coagulometers for INR self-testing are affected by patients’ perceptions about the INR testing device, the cost of device, trust in doctors/clinicians, and the age of the patient, which need to be considered prior to any intervention involving INR self-testing by patients. Manufacturers should focus on increasing the affordability of INR testing devices for patients’ self-testing and on the potential role of medical practitioners in supporting use of these medical devices as patients move from hospital to home testing.
Shah, Syed Ghulam Sarwar; Barnett, Julie; Kuljis, Jasna; Hone, Kate; Kaczmarski, Richard
Few studies have evaluated the feasibility of delivering syphilis point-of-care (POC) testing in outreach (nonclinical) settings in resource rich countries. The objectives of the study were to evaluate the feasibility and diagnostic performance of performing both HIV and syphilis POC testing in outreach settings and to document new cases identified in the study population. 1,265 outreach testing visits were offered syphilis and HIV POC testing and 81.5% (n = 1,031) consented to testing. In our population, the SD Bioline 3.0 Syphilis Test had a sensitivity of 85.3% [CI (68.9–95.0)], specificity of 100.0% [CI (99.6–100.0)], positive predictive value (PPV) of 100.0% [CI (88.1–100.0)], and negative predictive value (NPV) of 99.5% [CI (98.9–99.8)]. Test characteristics for the INSTI HIV-1/HIV-2 Antibody Test had a 100.0% sensitivity [CI (39.8–100.00], 99.8 specificity [CI (99.3–100)], 66.7% PPV [CI (22.3–95.7)], and 100.0% NPV [CI (99.6–100.0)]. Four new cases of syphilis and four new HIV cases were diagnosed. In summary, at risk population seeking STI testing found POC tests to be acceptable, the POC tests performed well in outreach settings, and new cases of syphilis and HIV were identified and linked to treatment and care.
Bergman, Joshua; Gratrix, Jennifer; Plitt, Sabrina; Fenton, Jayne; Archibald, Chris; Wong, Tom; Singh, Ameeta E.
European Concerted Action on Anticoagulation--comparison of fresh plasma and whole blood multicentre ISI calibrations of CoaguChek Mini and TAS PT-NC whole blood prothrombin time point-of-care monitors.
A procedure for using citrated fresh plasmas for International Sensitivity Index (ISI) calibration of two types of whole blood point-of-care test (POCT) prothrombin time (PT) monitor systems has been assessed in a multicentre study. The CoaguChek Mini and TAS PT-NC systems gave higher ISI with whole blood samples than with fresh plasma calibrations. However. there was good agreement between whole blood and fresh plasma monitor system International Normalised Ratio (INR) and the reference INR of target samples. Reliable INR can therefore be obtained with both whole blood and plasma samples on these two POCT systems based on their respective ISI. With the CoaguChek Mini system, the plasma calibration ISI can also be used to derive reliable INR with whole blood PT results. This was not possible with the TAS PT-NC system. PMID:12038790
Poller, L; Keown, M; Chauhan, N; van den Besselaar, A M H P; Tripodi, A; Shiach, C; Jespersen, J
Development of small footprint, disposable, fast, and inexpensive devices for pathogen detection in the field and clinic would benefit human and veterinary medicine by allow- ing evidence-based responses to future out breaks. We designed and tested an integrated nucleic acid extraction and amplifica- tion device employing a loop-mediated isothermal amplification (LAMP) or reverse transcriptase-LAMP assay. Our system pro- vides a
Jane P. Bearinger; Lawrence C. Dugan; Brian R. Baker; Sara B. Hall; Katja Ebert; Valerie Mioulet; Mikidache Madi; Donald P. King
Background Blood glucose (BG) meters used for assisted monitoring of blood glucose (AMBG) require different attributes compared with meters designed for home use. These include safety considerations (i.e., minimized risk of blood-borne pathogen transmission), capability for testing multiple blood sample types, and enhanced performance specifications. The OneTouch® Verio™Pro+ BG meter is designed to incorporate all of these attributes. Methods Meter accuracy was assessed in clinical studies with arterial, venous, and capillary blood samples with a hematocrit range of 22.9–59.8%. The effect of interferents, including anticoagulants, on accuracy was evaluated. The meter disinfection protocol was validated, and instructions for use and user acceptance of the system were assessed. Results A total of 97% (549/566) of BG measures from all blood sample types and 95.5% (191/200) of arterial blood samples were within ±12 mg/dl or 12.5% of reference measurements. The system was unaffected by 4 anticoagulants and 57 of 59 endogenous and exogenous compounds; it was affected by 2 compounds: pralidoxime iodide and xylose. Bleach wipes were sufficient to disinfect the meter. Users felt that the meter's quality control (QC) prompts would help them to comply with regulatory requirements. Conclusions The meter provided accurate measurements of different blood samples over a wide hematocrit range and was not affected by 57 physiologic and therapeutic compounds. The QC prompts and specific infection-mitigating design further aid to make this meter system practical for AMBG in care facilities.
MacRury, Sandra; Srinivasan, Aparna; Mahoney, John J.
Point-of-care testing (POCT) is traditionally defined as laboratory diagnostics performed at or near the site where clinical care is delivered. POCT thereby combines sample collection, analysis, and reporting of results into a robust integrated testing structure, with a simple user interface. The availability of reliable devices and consolidated tests for patient screening, diagnosis and monitoring has allowed broad diffusion of POCT to the patient's bedside, physician offices, pharmacies, other healthcare facilities, supermarkets, and even into the patient's home. However, current evidence clearly shows that POCT can be subjective, and might even amplify the traditional problems encountered in the preanalytical, analytical and postanalytical phases of the total testing process. This may especially be seen in inappropriateness of the test request, collection of unsuitable biological materials, inaccurate test performances, larger analytical imprecision, unsuitable report formatting, delayed reporting of critical value, and report recording/retrieval. POCT patient care service in the pharmacy can be regarded as a valuable option for the present and future since it might be beneficial for all parties. However, several economic, clinical and regulatory issues should also be addressed before this opportunity can turn into a real advantage for patients and the entire healthcare system. The most appropriate allocation of POCT within the diagnostic pathway, as well as its adjuvant role in screening, diagnosis and monitoring of diseases should also be clearly established in order to prevent widespread and deregulated implementation. PMID:20441470
Lippi, Giuseppe; Plebani, Mario; Favaloro, Emmanuel J; Trenti, Tommaso
BACKGROUND: Most antibiotic prescriptions for acute cough due to lower respiratory tract infections (LRTI) in primary care are not warranted. Diagnostic uncertainty and patient expectations and worries are major drivers of unnecessary antibiotic prescribing. A C-reactive protein (CRP) point of care test may help GPs to better guide antibiotic treatment by ruling out pneumonia in cases of low test results.
Jochen WL Cals; Rogier M Hopstaken; Christopher C Butler; Kerenza Hood; Johan L Severens; Geert-Jan Dinant
Abstract Background: Although fetal blood sampling for pH is well established the use of lactate has not been widely adopted. This study validated the performance and utility of a handheld point-of-care (POC) lactate device in comparison with the lactate and pH values obtained by the ABL 800 blood gas analyzer. Methods: The clinical performance and influences on accuracy and decision-making criteria were assessed with freshly taken fetal blood scalp samples (n=57) and umbilical cord samples (n=310). Bland-Altman plot was used for data plotting and analyzing the agreement between the two measurement devices and correlation coefficients (R2) were determined using Passing-Bablok regression analysis. Results: Sample processing errors were much lower in the testing device (22.8% vs. 0.5%). Following a preclinical assessment and calibration offset alignment (0.5 mmol/L) the test POC device showed good correlation with the reference method for lactate FBS (R2=0.977, p<0.0001, 95% CI 0.9 59-0.988), arterial cord blood (R2=0.976, p<0.0001, 95% CI 0.967-0.983) and venous cord blood (R2=0.977, p<0.0001, 95% CI 0.968-0.984). Conclusions: A POC device which allows for a calibration adjustment to be made following preclinical testing can provide results that will correlate closely to an incumbent lactate method such as a blood gas analyzer. The use of a POC lactate device can address the impracticality and reality of pH sample collection and testing failures experienced in day to day clinical practice. For the StatStrip Lactate meter we suggest using a lactate cut-off of 5.1 mmol/L for predicting fetal acidosis (pH<7.20). PMID:24406288
Reif, Philipp; Lakovschek, Ioanna; Tappauf, Carmen; Haas, Josef; Lang, Uwe; Schöll, Wolfgang
Introduction Despite the rapid expansion of antiretroviral therapy (ART) programmes in developing countries, pre-treatment losses from care remain a challenge to improving access to treatment. Youth and adolescents have been identified as a particularly vulnerable group, at greater risk of loss from both pre-ART and ART care. Point-of-care (POC) CD4 testing has shown promising results in improving linkage to ART care. In Khayelitsha township, South Africa, POC CD4 testing was implemented at a clinic designated for youth aged 12–25 years. We assessed whether there was an associated reduction in attrition between HIV testing, assessment for eligibility and ART initiation. Methods A before-and-after observational study was conducted using routinely collected data. These were collected on patients from May 2010 to April 2011 (Group A) when baseline CD4 count testing was performed in a laboratory and results were returned to the clinic within two weeks. Same-day POC CD4 testing was implemented in June 2011, and data were collected on patients from August 2011 to July 2012 (Group B). Results A total of 272 and 304 youth tested HIV-positive in Group A and Group B, respectively. Group B patients were twice as likely to have their ART eligibility assessed compared to Group A patients: 275 (90%) vs. 183 (67%) [relative risk (RR)=2.4, 95% CI: 1.8–3.4, p<0.0001]. More patients in World Health Organization (WHO) Stage 1 disease (85% vs. 69%), with CD4 counts?350 cells/µL (58% vs. 35%) and more males (13% vs. 7%) were detected in Group B. The proportion of eligible patients who initiated ART was 50% and 44% (p=0.6) in Groups B and A, respectively; and 50% and 43% (p=0.5) when restricted to patients with baseline CD4 count?250 cells/µL. Time between HIV-testing and ART initiation was reduced from 36 to 28 days (p=0.6). Discussion POC CD4 testing significantly improved assessment for ART eligibility. The improvement in the proportion initiating ART and the reduction in time to initiation was not significant due to sample size limitations. Conclusions POC CD4 testing reduced attrition between HIV-testing and assessment of ART eligibility. Strategies to improve uptake of ART are needed, possibly by improving patient support for HIV-positive youth immediately after diagnosis.
Patten, Gabriela EM; Wilkinson, Lynne; Conradie, Karien; Isaakidis, Petros; Harries, Anthony D; Edginton, Mary E; De Azevedo, Virginia; van Cutsem, Gilles
Background Toxicology and Emergency medicine textbooks recommend measurement of acetylcholinesterase (AChE) in all symptomatic cases of organophosphorus (OP) poisoning but laboratory facilities are limited in rural Asia. The accuracy of point-of-care (POC) acetylcholinesterase testing has been demonstrated but it remains to be shown whether results would be valued by clinicians. This study aims to assess the effect of seeing AChE POC test results on the knowledge, attitudes and practices of doctors who frequently manage OP poisoning. Methods We surveyed 23 clinicians, who had different levels of exposure to seeing AChE levels in OP poisoned patients, on a) knowledge of OP poisoning and biomarker interpretation, b) attitudes towards AChE in guiding poison management, oxime therapy and discharge decisions, and c) practices of ordering AChE in poisoning scenarios. Results An overall high proportion of doctors valued the test (68-89%). However, we paradoxically found that doctors who were more experienced in seeing AChE results valued the test less. Lower proportions valued the test in guidance of acute poisoning management (50%, p = 0.015) and guidance of oxime therapy (25%, p = 0.008), and it was apparent it would not generally be used to facilitate early discharge. The highest proportion of respondents valued it on admission (p < 0.001). A lack of correlation of test results with the clinical picture, and a perception that the test was a waste of money when compared to clinical observation alone were also comments raised by some of the respondents. Greater experience with seeing AChE test results was associated with increased knowledge (p = 0.034). However, a disproportionate lack of knowledge on interpretation of biomarkers and the pharmacology of oxime therapy (12-50%) was noted, when compared with knowledge on the mechanism of OP poisoning and management (78-90%). Conclusions Our findings suggest an AChE POC test may not be valued by rural doctors. The practical use of AChE in OP poisoning management is complex, and a poor understanding of how to interpret test results may have affected its perceived utility. Future research should evaluate the impact of providing both AChE and training in interpretation on clinicians’ attitudes and practice.
Background A rapid diagnostic test for active tuberculosis (TB) at the clinical point-of-care could expedite case detection and accelerate TB treatment initiation. We assessed the diagnostic accuracy of a rapid urine lipoarabinomannan (LAM) test for TB screening among HIV-infected adults in a TB-endemic setting. Methods We prospectively enrolled newly-diagnosed HIV-infected adults (?18 years) at 4 outpatient clinics in Durban from Oct 2011-May 2012, excluding those on TB therapy. A physician evaluated all participants and offered CD4 cell count testing. Trained study nurses collected a sputum sample for acid-fast bacilli smear microscopy (AFB) and mycobacterial culture, and performed urine LAM testing using Determine™ TB LAM in the clinic. The presence of a band regardless of intensity on the urine LAM test was considered positive. We defined as the gold standard for active pulmonary TB a positive sputum culture for Mycobacterium tuberculosis. Diagnostic accuracy of urine LAM was assessed, alone and in combination with smear microscopy, and stratified by CD4 cell count. Results Among 342 newly-diagnosed HIV-infected participants, 190 (56%) were male, mean age was 35.6 years, and median CD4 was 182/mm3. Sixty participants had culture-positive pulmonary TB, resulting in an estimated prevalence of 17.5% (95% CI 13.7-22.0%). Forty-five (13.2%) participants were urine LAM positive. Mean time from urine specimen collection to LAM test result was 40 minutes (95% CI 34–46 minutes). Urine LAM test sensitivity was 28.3% (95% CI 17.5-41.4) overall, and 37.5% (95% CI 21.1-56.3) for those with CD4 count <100/mm3, while specificity was 90.1% (95% CI 86.0-93.3) overall, and 86.9% (95% CI 75.8-94.2) for those with CD4?100/mm3. When combined with sputum AFB (either test positive), sensitivity increased to 38.3% (95% CI 26.0-51.8), but specificity decreased to 85.8% (95% CI 81.1-89.7). Conclusions In this prospective, clinic-based study with trained nurses, a rapid urine LAM test had low sensitivity for TB screening among newly-diagnosed HIV-infected adults, but improved sensitivity when combined with sputum smear microscopy.
We compared results obtained with the Nanosphere Verigene® System, a novel point-of-care (POC) genetic test capable of analysing 11 CYP2C19 variants within 3 hours, to an established, validated genotyping method (Affymetrix™ DMET+; reference assay) for identifying extensive and reduced metabolisers of clopidogrel. Based on genotyping, patients (N=82) with stable coronary artery disease on clopidogrel 75 mg daily were defined as extensive metabolisers (*1/*1, *1/*17, *17/*17), reduced metabolisers (*1/*2, *1/*8, *2/*2, *2/*3), or of indeterminate metaboliser status (*2/*17). Pharmacokinetic exposure to clopidogrel's active metabolite and pharmacodynamic measures with P2Y12 reaction units (PRU) (VerifyNow®P2Y12 assay) and VASP PRI (PRI) were also assessed. There was a 99.9% overall concordance of marker-level data between the Nanosphere Verigene and DMET+ systems in identifying the CYP2C19 variants and 100% agreement in classifying the patients as extensive (n=59) or reduced metabolisers (n=15). Extensive metabolisers had significantly higher active metabolite exposure than reduced metabolisers (LS means 12.6 ng*h/ml vs 7.7 ng*h/ml; p<0.001). Extensive metabolisers also had lower PRU (LS means 158 vs 212; p=0.003) and VASP PRI (LS means 48% vs 63%, p=0.01) compared to reduced metabolisers. Rates of high on-treatment platelet reactivity were higher in reduced metabolisers compared to extensive metabolisers (VASP PRI ?50%: 79% vs 47%; PRU >235: 33% vs 16%). The Nanosphere Verigene CBS system identified 11 CYP2C19 alleles in less than 3 hours with a high degree of accuracy when compared to a conventional method, and was further validated against pharmacokinetic and pharmacodynamic phenotypes. PMID:24402637
Erlinge, D; James, S; Duvvuru, S; Jakubowski, J A; Wagner, H; Varenhorst, C; Tantry, U S; Brown, P B; Small, D; Moser, B A; Sundseth, S S; Walker, J R; Winters, K J; Gurbel, P A
Clopidogrel is a prodrug which is converted into active metabolite by cytochrome P450 isoenzyme, CYP2C19. Numerous polymorphisms of CYP2C19 are reported, and a strong link exists between loss-of-function (LOF) or gain-of-function polymorphisms, clopidogrel metabolism, and clinical outcome. Hence, a fully automated point-of-care CYP2C19 genotyping assay is more likely to bring personalized antiplatelet therapy into real practice. We assessed the feasibility of the Verigene 2C19/CBS Nucleic Acid Test, a fully automated microarray-based assay, compared to bidirectional sequencing, and performed VerifyNow P2Y12 assay to evaluate the effect of CYP2C19 polymorphisms on on-treatment platelet reactivity in 57 Korean patients treated with clopidogrel after percutaneous coronary intervention. The Verigene 2C19/CBS assay identified ?2, ?3, and ?17 polymorphisms with 100% concordance to bidirectional sequencing in 180 minutes with little hands-on time. Patients were classified into 4 groups: extensive (?1/?1; n = 12, 21.1%), intermediate (?1/?2, ?1/?3; n = 33, 57.9%), poor (?2/?2, ?2/?3, and ?3/?3; n = 11, 19.3%), and ultrarapid metabolizers (?1/?17; n = 1, 1.8%). The prevalence of the CYP2C19???2, ?3, and ?17 alleles was 36.0%, 12.3%, and 0.9%. Platelet reactivity showed gene dose response according to the number of CYP2C19 LOF allele. In conclusion, the Verigene 2C19/CBS assay gave accurate CYP2C19 genotype results which were in well match with the differing on-treatment platelet reactivity.
Chae, Hyojin; Kim, Myungshin; Koh, Yoon-Seok; Hwang, Byung-Hee; Kang, Min-Kyu; Kim, Yonggoo; Park, Hae-il; Chang, Kiyuk
Development of reliable, easy-to-use, rapid diagnostic tests (RDTs) to detect glucose-6-phosphate dehydrogenase (G6PD) deficiency at point of care is essential to deploying primaquine therapies as part of malaria elimination strategies. We assessed a kit under research and development called CareStart™ G6PD deficiency screening test (Access Bio, New Jersey, USA) by comparing its performance to quantitative G6PD enzyme activity using a standardized spectrophotometric method (‘gold standard’). Blood samples (n?=?903) were collected from Cambodian adults living in Pailin province, western Cambodia. G6PD enzyme activities ranged from 0 to 20.5 U/g Hb (median 12.0 U/g Hg). Based on a normal haemoglobin concentration and wild-type G6PD gene, the normal values of G6PD enzymatic activity for this population was 3.6 to 20.5 U/g Hg (95th percentiles from 5.5 to 17.2 U/g Hg). Ninety-seven subjects (10.7%) had <3.6 U/g Hg and were classified as G6PD deficient. Prevalence of deficiency was 15.0% (64/425) among men and 6.9% (33/478) among women. Genotype was analyzed in 66 G6PD-deficient subjects and 63 of these exhibited findings consistent with Viangchang genotype. The sensitivity and specificity of the CareStart™ G6PD deficiency screening test was 0.68 and 1.0, respectively. Its detection threshold was <2.7 U/g Hg, well within the range of moderate and severe enzyme deficiencies. Thirteen subjects (1.4%, 12 males and 1 female) with G6PD enzyme activities <2 U/g Hg were falsely classified as “normal” by RDT. This experimental RDT test here evaluated outside of the laboratory for the first time shows real promise, but safe application of it will require lower rates of falsely “normal” results.
Kim, Saorin; Nguon, Chea; Guillard, Bertrand; Duong, Socheat; Chy, Sophy; Sum, Sarorn; Nhem, Sina; Bouchier, Christiane; Tichit, Magali; Christophel, Eva; Taylor, Walter R. J.; Baird, John Kevin; Menard, Didier
Background Influenza infections induce considerable disease burden in young children. Biomarkers for the monitoring of disease activity at the point-of-care (POC) are currently lacking. Recent methodologies for fluorescence-based rapid testing have been developed to provide improved sensitivities with the initial diagnosis. The present study aims to explore the utility of second-generation rapid testing during longitudinal follow-up of influenza patients (Rapid Influenza Follow-up Testing?=?RIFT). Signal/control fluorescent readouts (Quantitative Influenza Follow-up Testing?=?QIFT) are evaluated as a potential biomarker for the monitoring of disease activity at the POC. Methods and Findings RIFT (SOFIA) and QIFT were performed at the POC and compared to blinded RT-PCR at the National Reference Centre for Influenza. From 10/2011-4/2013, a total of 2048 paediatric cases were studied prospectively; 273 cases were PCR-confirmed for influenza. During follow-up, RIFT results turned negative either prior to PCR (68%), or simultaneously (30%). The first negative RIFT occurred after a median of 8 days with a median virus load (VL) of 5.6×10?3 copies/ml and cycle threshold of 37, with no evidence of viral rebound. Binning analysis revealed that QIFT differentiated accurately between patients with low, medium and high viral titres. QIFT increase/decrease showed 88% agreement (sensitivity?=?52%, specificity?=?95%) with VL increase/decrease, respectively. QIFT-based viral clearance estimates showed similar values compared to PCR-based estimates. Variations in viral clearance rates were lower in treated compared to untreated patients. The study was limited by use of non-invasive, semi-quantitative nasopharyngeal samples. VL measurements below the limit of detection could not be quantified reliably. Conclusions During follow-up, RIFT provides a first surrogate measure for influenza disease activity. A “switch” from positive to negative values may indicate a drop in viral load below a critical threshold, where rebound is no longer expected. QIFT may provide a useful tool for the monitoring of disease burden and viral clearance at the POC.
Chen, Xi; Pouran Yousef, Kaveh; Duwe, Susanne; Karsch, Katharina; Grover, Sandeep; Wahlisch, Stephanie; Obermeier, Patrick; Tief, Franziska; Muhlhans, Susann; Seeber, Lea; von Kleist, Max; Schweiger, Brunhilde; Rath, Barbara
Background—Diagnostic strategies with ECG and serum cardiac markers have been used to rule out acute myocardial infarction in 6 to 12 hours. The present study evaluated whether a multimarker strategy that used point-of-care measurement of myoglobin, creatine kinase (CK)-MB, and troponin I could exclude acute myocardial infarction in #3 hours. Methods and Results—We prospectively enrolled consecutive patients (n 5817) in
James McCord; Richard M. Nowak; Peter A. McCullough; Craig Foreback; Steven Borzak; Glenn Tokarski; Michael C. Tomlanovich; Gordon Jacobsen; W. Douglas Weaver
Abstract Context. Nitromethane interferes with Jaffé measurements of creatinine, potentially mimicking acute kidney injury. Objectives. We determined the proportional contribution of nitromethane in blood samples to creatinine measured by the Jaffé colorimetric and the point-of-care (POC) reactions and determined whether the difference can reliably estimate the concentration of nitromethane. Additionally, we determined whether the presence of nitromethane interferes with anion/osmolal gaps and ascertained the stability of nitromethane in serum after 7 days. Methods. Nitromethane was added to whole blood from four healthy volunteers to achieve concentrations of 0, 0.25, 0.5, 1, and 2 mmol/L. The following tests were performed: creatinine (Jaffé and POC), electrolytes (associated with Jaffé and POC), osmolality and nitromethane concentration (gas chromatography [GC]). Remaining samples were refrigerated and reanalyzed using GC at 7 days. Anion and osmolal gaps were calculated. Proportional recovery and degradation of nitromethane were measured using GC. Data were analyzed for agreement with single-factor ANOVA (p = 0.05). Results. Mean creatinine for POC and Jaff methods were 0.93 vs. 0.76 mg/dL, respectively. Jaff creatinine concentrations increased linearly with increasing nitromethane concentrations (R(2) = 1, p = 0.01): measured creatinine (mg/dL) = 7.1*nitromethane (mmol/L) = 0.79. POC creatinine remained unchanged across the range of nitromethane concentrations (p = 0.99). Anion and osmolal gaps also remained unchanged. Nitromethane was reliably identified in all sample concentrations using GC on Day 0. Detection of 0.25 mmol/L nitromethane was not consistently recovered on Day 7. Nitromethane degradation was most pronounced at 2 mmol/L concentrations (81% recovery). Conclusions. Nitromethane alters apparent concentration of creatinine using the Jaffé reaction in a linear fashion but not when using the POC reaction. Measured difference between Jaffé and POC creatinine may identify the presence and estimate concentration of nitromethane. Presence of nitromethane did not alter the anion or osmolal gap; thus it would not potentially interfere with the diagnosis of co-exposure to a toxic alcohol. PMID:24844579
Cao, D; Maynard, S; Mitchell, A M; Kerns, W P; Beuhler, M
The usefulness of a point-of-care immunochromatographic dual test for the simultaneous detection of both nontreponemal and Treponema pallidum-specific antibodies (Chembio Diagnostics Systems Inc., Medford, NY, USA) was assessed in various situations related to syphilis, by reference to conventional syphilis serology. Thawed sera were obtained from 100 adults including 36 primary syphilis, 6 secondary syphilis, 6 re-infection, 9 recently-treated syphilis, and 43 old syphilis. Doubtful reactivities for the treponemal line were considered positive; doubtful reactivities for the nontreponemal line were considered positive only when the treponemal line was present. The sensitivity, the specificity, and its concordance to gold standard serology of treponemal line were high, around 90%. The sensitivity of nontreponemal line was 96.3%, its specificity 76.7%, and its concordance 83.4%. In conclusion, the dual rapid test from Chembio Diagnostics Systems Inc. is useful for rapid point-of-care diagnosis in the various situations encountered with patients suffering from syphilis. PMID:23999937
Guinard, Jérôme; Prazuck, Thierry; Péré, Hélène; Poirier, Claire; LeGoff, Jérôme; Boedec, Erwan; Guigon, Aurélie; Day, Nesrine; Bélec, Laurent
This study describes the development, implementation and management of a multi-faceted quality assurance program called Quality Assurance for Aboriginal Medical Services (QAAMS) to support point-of-care HbA(1c) testing on the Bayer DCA 2000 in Aboriginal people with diabetes from 45 Australian Aboriginal Community Controlled Health Services. The quality assurance program comprised four elements: production of culturally appropriate education resources, formal training for Aboriginal Health Workers conducting HbA(1c) testing, an external quality assurance program and on-going quality management support services including a help hotline and an annual workshop. Aboriginal Health Workers were required to test two quality assurance (QAAMS) samples in a blind sense every month since July 1999. Samples were linearly related and comprised six paired levels of HbA(1c). The short and long term performance of each service's DCA 2000 was reviewed monthly and at the end of each six month testing cycle. The average participation rate over 7 six-monthly QAAMS testing cycles was 88%. 84% of 3100 quality assurance tests performed were within preset limits of acceptability. The median precision (CV%) for HbA(1c) testing has averaged 3.8% across the past 5 cycles (range 3.4 to 4.0%) and is continuing to improve. The introduction of a medical rebate for HbA(1c) testing has ensured the program's sustainability. Through continuing education and training, Aboriginal Health Workers have achieved consistent analytical performance for HbA(1c) testing on the DCA 2000, equivalent to that of laboratory scientists using the same instrument. This unique quality assurance model can be readily adapted to other Indigenous health settings and other point-of-care tests and instruments. PMID:18568052
Shephard, Mark D; Gill, Janice P
This study describes the development, implementation and management of a multi-faceted quality assurance program called Quality Assurance for Aboriginal Medical Services (QAAMS) to support point-of-care HbA1c testing on the Bayer DCA 2000 in Aboriginal people with diabetes from 45 Australian Aboriginal Community Controlled Health Services. The quality assurance program comprised four elements: production of culturally appropriate education resources, formal training for Aboriginal Health Workers conducting HbA1c testing, an external quality assurance program and on-going quality management support services including a help hotline and an annual workshop. Aboriginal Health Workers were required to test two quality assurance (QAAMS) samples in a blind sense every month since July 1999. Samples were linearly related and comprised six paired levels of HbA1c. The short and long term performance of each service’s DCA 2000 was reviewed monthly and at the end of each six month testing cycle. The average participation rate over 7 six-monthly QAAMS testing cycles was 88%. 84% of 3100 quality assurance tests performed were within preset limits of acceptability. The median precision (CV%) for HbA1c testing has averaged 3.8% across the past 5 cycles (range 3.4 to 4.0%) and is continuing to improve. The introduction of a medical rebate for HbA1c testing has ensured the program’s sustainability. Through continuing education and training, Aboriginal Health Workers have achieved consistent analytical performance for HbA1c testing on the DCA 2000, equivalent to that of laboratory scientists using the same instrument. This unique quality assurance model can be readily adapted to other Indigenous health settings and other point-of-care tests and instruments.
Shephard, Mark D; Gill, Janice P
Integrating POC CD4 testing technologies into HIV counseling and testing (HCT) programs may improve post-HIV testing linkage to care and treatment. As evaluations of these technologies in program settings continue, estimates of the costs of POC CD4 tests to the service provider will be needed and estimates have begun to be reported. Without a consistent and transparent methodology, estimates of
Bruce Larson; Kathryn Schnippel; Buyiswa Ndibongo; Lawrence Long; Matthew P. Fox; Sydney Rosen
We described the evaluation of the Syphilis Screening & Confirm Assay for the simultaneous detection of nontreponemal and treponemal antibodies. A total of 248 samples were evaluated. The sensitivity of the tests was 98.8%, 99.5% and 98.9%, while specificity was 94.7%, 88.9% and 93.2%, respectively, as compared with the rapid plasma reagin, Treponema pallidum hemagglutination assay, and fluorescent treponemal antibody absorption tests. PMID:25013972
Castro, Rita; Lopes, Angela; da Luz Martins Pereira, Filomena
AIM: To assess the role of the 13C-methacetin breath test (MBT) in patients with acute liver disease. METHODS: Fifteen patients with severe acute liver disease from diverse etiologies were followed-up with 13C-MBT during the acute phase of their illnesses (range 3-116 d after treatment). Patients fasted for 8 h and ingested 75 mg of methacetin prior to the MBT. We compared results from standard clinical assessment, serum liver enzymes, synthetic function, and breath test scores. RESULTS: Thirteen patients recovered and two patients died. In patients that recovered, MBT parameters improved in parallel with improvements in lab results. Evidence of consistent improvement began on day 3 for MBT parameters and between days 7 and 9 for blood tests. Later convergence to normality occurred at an average of 9 d for MBT parameters and from 13 to 28 d for blood tests. In both patients that died, MBT parameters remained low despite fluctuating laboratory values. CONCLUSION: The 13C-MBT provides a rapid, non-invasive assessment of liver function in acute severe liver disease of diverse etiologies. The results of this pilot clinical trial suggest that the MBT may offer greater sensitivity than standard clinical tests for managing patients with severe acute liver disease.
Lalazar, Gadi; Adar, Tomer; Ilan, Yaron
Background The urine lipoarabinomannan (LAM) strip-test (Determine®-TB) can rapidly rule-in TB in HIV-infected persons with advanced immunosuppression. However, given high rates of empiric treatment amongst hospitalised patients in high-burden settings (?50%) it is unclear whether LAM can add any value to clinical decision making, or identify a subset of patients with unfavourable outcomes that would otherwise have been missed by empiric treatment. Methods 281 HIV-infected hospitalised patients with suspected TB received urine LAM strip testing, and were categorised as definite (culture-positive), probable-, or non-TB. Both the proportion and morbidity of TB cases identified by LAM testing, early empiric treatment (initiated prior to test result availability) and a set of clinical predictors were compared across groups. Results 187/281 patients had either definite- (n?=?116) or probable-TB (n?=?71). As a rule-in test for definite and probable-TB, LAM identified a similar proportion of TB cases compared to early empiric treatment (85/187 vs. 93/187, p?=?0.4), but a greater proportion than classified by a set of clinical predictors alone (19/187; p<0.001). Thirty-nine of the 187 (21%) LAM-positive patients who had either definite- or probable-TB were missed by early empiric treatment, and of these 25/39 (64%) would also have been missed by smear microscopy. Thus, 25/187 (8%) of definite- or probable-TB patients with otherwise delayed initiation of TB treatment could be detected by the LAM strip test. LAM-positive patients missed by early empiric treatment had a lower median CD4 count (p?=?0.008), a higher median illness severity score (p?=?0.001) and increased urea levels (p?=?0.002) compared to LAM-negative patients given early empiric treatment. Conclusions LAM strip testing outperformed TB diagnosis based on clinical criteria but in day-to-day practice identified a similar proportion of patients compared to early empiric treatment. However, compared to empiric treatment, LAM identified a different subset of patients with more advanced immunosuppression and greater disease severity.
Peter, Jonathan G.; Theron, Grant; Dheda, Keertan
Background Determining the variation of circulating cathodic antigen (CCA) in urine and egg counts variation in stool between days in Schistosoma mansoni (S. mansoni) infected individuals is vital to decide whether or not to rely on a single-sample test for diagnosis of Schistosomiasis. In this study, the magnitude of day-to-day variation in urine-CCA test scores and in faecal egg counts was evaluated in school children in Ethiopia. Methods A total of 620 school children (age 8 to 12 years) were examined for S. mansoni infection using double Kato-Katz and single urine-CCA cassette methods (batch 32727) on three consecutive days. Results The prevalence of S. mansoni infection was 81.1% based on triple urine-CCA-cassette test and 53.1% based on six Kato-Katz thick smears. Among the study participants, 26.3% showed fluctuation in urine CCA and 32.4% showed fluctuation in egg output. Mean egg count as well as number of cases in each class of intensity and intensity of cassette band color varied over the three days of examination. Over 85% of the children that showed day-to-day variations in status of S. mansoni infection from negative to positive or vice versa by the Kato-Katz and the CCA methods had light intensity of infection. The fluctuation in both the CCA test scores and faecal egg count was not associated with age and sex. Conclusions The current study showed day-to-day variation in CCA and Kato-Katz test results of children infected with S. mansoni. This indicates the necessity of more than one urine or stool samples to be collected on different days for more reliable diagnosis of S. mansoni infection in low endemic areas.
Objective To assess the effect of general practitioner testing for C reactive protein (disease approach) and receiving training in enhanced communication skills (illness approach) on antibiotic prescribing for lower respiratory tract infection.Design Pragmatic, 2×2 factorial, cluster randomised controlled trial.Setting 20 general practices in the Netherlands.Participants 40 general practitioners from 20 practices recruited 431 patients with lower respiratory tract infection.Main outcome
Jochen W L Cals; Christopher C Butler; Rogier M Hopstaken; Kerenza Hood; Geert-Jan Dinant
The object was to assess the variability in displayed International Normalised Ratio (INR) between monitors of the same manufacture using whole blood samples from the same subjects. Two brands of monitor, CoaguChek Mini and the TAS PT-NC were tested. 14 instruments of each brand were tested on the same day at the same laboratory by the same operator using identical blood samples to avoid between-centre differences in samples and operator technique. Whole blood samples from two normal donors and four coumarin-treated patients were tested to assess between-instrument variability of INR. Results have been coded. There was a much wider dispersion of INR on Brand B than on Brand A. One Brand A instrument failed to give a result with one of the two whole blood samples from one patient. One Brand B monitor gave an aberrant result with one of the samples from a normal subject. On both brands of monitor, INR variability appeared to be due mainly to duplication differences rather than between-instrument variability on both normal and coumarin whole blood samples. PMID:12529750
Poller, L; Keown, M; Chauhan, N; Shiach, C; van den Besselaar, A M H P; Tripodi, A; Jespersen, J
The aim of the study was to evaluate the performance of the new mariPOC(®) method against the direct fluorescent antibody assay (DFA) as the primary reference method for rapid virus detection from nasopharyngeal aspirates and swab samples. The study was an open prospective evaluation during the seasonal winter epidemics in the Mikkeli Central Hospital, Finland. Altogether, 283 samples were analyzed; 124 (43.8%) were from young children (<5 years old). Discrepant samples were resolved by PCR. With nasopharyngeal aspirate samples, the sensitivity and clinical specificity of the mariPOC(®) assay for influenza A virus and respiratory syncytial virus, were 85.7% (CI 69.7-95.2) and 90% (CI 52.0-80.5), and 100% and 99.5%, respectively. The mariPOC(®) performed less well with swab samples having sensitivities at 77.3% (CI 54.6-92.2) and 67.4% (CI 52-80.5), respectively. The specificities were as for nasopharyngeal aspirates. Importantly, similar performance was observed regardless of the cohort age group. In conclusion, the mariPOC(®) test system has a high potential and utility in duty units because it is fast, simple, and multianalyte. The importance of personnel training for proper sample collection should be emphasized. PMID:23852685
Tuuminen, Tamara; Suomala, Päivi; Koskinen, Janne O
An early evaluation of clinical and economic costs and benefits of implementing point of care NAAT tests for Chlamydia trachomatis and Neisseria gonorrhoea in genitourinary medicine clinics in England
Objectives To estimate the costs and benefits of clinical pathways incorporating a point of care (POC) nucleic acid amplification test (NAAT) for chlamydia and gonorrhoea in genitourinary medicine (GUM) clinics compared with standard off-site laboratory testing. Method We simulated 1.2 million GUM clinic attendees in England. A simulation in Microsoft Excel was developed to compare existing standard pathways of management for chlamydia and gonorrhoea with a POC NAAT. We conducted scenario analyses to evaluate the robustness of the model findings. The primary outcome was the incremental cost-effectiveness ratio. Secondary outcomes included the number of inappropriate treatments, complications and transmissions averted. Results The baseline cost of using the point of POC NAAT was £103.9 million compared with £115.6 million for standard care. The POC NAAT was also associated with a small increase of 46 quality adjusted life years, making the new test both more effective and cheaper. Over 95?000 inappropriate treatments might be avoided by using a POC NAAT. Patients receive diagnosis and treatment on the same day as testing, which may also prevent 189 cases of pelvic inflammatory disease and 17?561 onward transmissions annually. Discussion Replacing standard laboratory tests for chlamydia and gonorrhoea with a POC test could be cost saving and patients would benefit from more accurate diagnosis and less unnecessary treatment. Overtreatment currently accounts for about a tenth of the reported treatments for chlamydia and gonorrhoea and POC NAATs would effectively eliminate the need for presumptive treatment.
Turner, Katherine M E; Round, Jeff; Horner, Patrick; Macleod, John; Goldenberg, Simon; Deol, Arminder; Adams, Elisabeth J
The burden of health-care related services in a global era with continuously increasing population and inefficient dissipation of the resources requires effective solutions. From this perspective, point-of-care diagnostics is a demanded field in clinics. It is also necessary both for prompt diagnosis and for providing health services evenly throughout the population, including the rural districts. The requirements can only be fulfilled by technologies whose productivity has already been proven, such as complementary metal-oxide-semiconductors (CMOS). CMOS-based products can enable clinical tests in a fast, simple, safe, and reliable manner, with improved sensitivities. Portability due to diminished sensor dimensions and compactness of the test set-ups, along with low sample and power consumption, is another vital feature. CMOS-based sensors for cell studies have the potential to become essential counterparts of point-of-care diagnostics technologies. Hence, this review attempts to inform on the sensors fabricated with CMOS technology for point-of-care diagnostic studies, with a focus on CMOS image sensors and capacitance sensors for cell studies.
Adiguzel, Yekbun; Kulah, Haluk
We report on the development of a portable fluorescence detection system. By combining a CMOS sensor and crosspolarization scheme, we achieved multiplexed detection with a single white emission LED excitation. We demonstrated fluorescence detection of Fluorescein and Rhodamine B in PDMS channels and achieved 1?M limit of detection (LOD). Microparticles with green and red fluorescence were detected simultaneously without changing the light sources or filters. We were able to clearly resolve microparticles, even if aggregated. The compact microfluorescence approach offers high spatial and spectral resolution, and is suitable for multiplexed detection in point-of-care applications.
Shen, Li; Ratterman, Mike; Stites, Tyler; Klotzkin, David; Papautsky, Ian
Point-of-care lung ultrasound represents an emerging and useful technique in the management of pulmonary diseases. For many years, thoracic ultrasonography was limited to the study of pleural effusion and thoracic superficial masses because alveolar air and bones of the thoracic cage limit the propagation of the ultrasound beam. Only recently has been highlighted that, by the fact, lung ultrasound works like a real densitometer that is highly sensitive to variations of the pulmonary content and balance between air and fluids. Dynamic and static analysis of a combination of sonographic artifacts and real images makes it possible an accurate diagnosis of many lung disorders, particularly when lung ultrasound is applied in the emergency and critical care setting. Sonography is useful in the diagnostic process of lung diseases where the alveolar air is reduced and interstitial fluids are increased, but also when air or fluids are collected in the pleural space. This article analyzes the basic principles of point-of-care lung ultrasound and all the supposed limitations to the diagnostic usefulness of this technique. Moreover, the article reviews the three main fields of application for lung ultrasound: interstitial, alveolar and pleural syndromes. PMID:24894615
Effective prevention of HIV/AIDS requires early diagnosis, initiation of therapy, and regular plasma viral load monitoring of the infected individual. In addition, incidence estimation using accurate and sensitive assays is needed to facilitate HIV prevention efforts in the public health setting. Therefore, more affordable and accessible point-of-care (POC) technologies capable of providing early diagnosis, HIV viral load measurements, and CD4 counts in settings where HIV is most prevalent are needed to enable appropriate intervention strategies and ultimately stop transmission of the virus within these populations to achieve the future goal of an AIDS-free generation. This review discusses the available and emerging POC technologies for future application to these unmet public health needs.
Hewlett, Indira K.
Background Prompt diagnosis of acute HIV infection (AHI) benefits the individual and provides opportunities for public health intervention. The aim of this study was to describe most common signs and symptoms of AHI, correlate these with early disease progression and develop a clinical algorithm to identify acute HIV cases in resource limited setting. Methods 245 South African women at high-risk of HIV-1 were assessed for AHI and received monthly HIV-1 antibody and RNA testing. Signs and symptoms at first HIV-positive visit were compared to HIV-negative visits. Logistic regression identified clinical predictors of AHI. A model-based score was assigned to each predictor to create a risk score for every woman. Results Twenty-eight women seroconverted after a total of 390 person-years of follow-up with an HIV incidence of 7.2/100 person-years (95%CI 4.5–9.8). Fifty-seven percent reported ?1 sign or symptom at the AHI visit. Factors predictive of AHI included age <25 years (OR?=?3.2; 1.4–7.1), rash (OR?=?6.1; 2.4–15.4), sore throat (OR?=?2.7; 1.0–7.6), weight loss (OR?=?4.4; 1.5–13.4), genital ulcers (OR?=?8.0; 1.6–39.5) and vaginal discharge (OR?=?5.4; 1.6–18.4). A risk score of 2 correctly predicted AHI in 50.0% of cases. The number of signs and symptoms correlated with higher HIV-1 RNA at diagnosis (r?=?0.63; p<0.001). Conclusions Accurate recognition of signs and symptoms of AHI is critical for early diagnosis of HIV infection. Our algorithm may assist in risk-stratifying individuals for AHI, especially in resource-limited settings where there is no routine testing for AHI. Independent validation of the algorithm on another cohort is needed to assess its utility further. Point-of-care antigen or viral load technology is required, however, to detect asymptomatic, antibody negative cases enabling early interventions and prevention of transmission.
Mlisana, Koleka; Sobieszczyk, Magdalena; Werner, Lise; Feinstein, Addi; van Loggerenberg, Francois; Naicker, Nivashnee; Williamson, Carolyn; Garrett, Nigel
Lateral flow tests (LFTs) are well-suited for rapid point-of-care testing in low resource settings. The wicking action of the paper strip moves the sample and reagents through the device without a need for pumps, but LFTs are typically limited to tests that can be carried out in a single fluidic step. The materials from LFTs can be reconfigured to create paper networks that automatically carry out multi-step fluidic operations, while retaining the same easy-to-use format as a conventional LFT. Here, we describe basic principles of wicking and system-level behavior of paper networks by analogy to electrical circuits. We describe key design principles for a previously-developed 2D paper network (2DPN) and introduce an alternative linear paper network (Pseudo-1DPN) that takes advantage of system-level behavior to perform clean sequential fluid delivery while reducing device running time.
Dharmaraja, Shivani; Lafleur, Lisa; Byrnes, Samantha; Kauffman, Peter; Buser, Josh; Toley, Bhushan; Fu, Elain; Yager, Paul; Lutz, Barry
Background Emergency Departments (ED) have a high flow of patients and time is often crucial. New technologies for laboratory analysis have been developed, including Point of Care Technologies (POCT), which can reduce the transport time and time of analysis significantly compared with central laboratory services. However, the question is if the time to clinical action is also reduced if a decisive laboratory answer is available during the first contact between the patient and doctor. The present study addresses this question: Does a laboratory answer, provided by POCT to the doctor who first attends the patient on admission, change the time to clinical decision in commonly occurring diseases in an ED compared with the traditional service from a central laboratory? Methods We performed a randomised clinical trial with parallel design and allocation ratio 1:1. The eligibility Criteria were: All patients referred from General Practitioner or another referring doctor suspected for a deep venous thrombosis (DVT), acute coronary syndrome (ACS), acute appendicitis (AA) or acute infection (ABI). The outcome measure was the time spend from the blood sample was taken to a clinical decision was made. Results The study period took place in October--November 2009 and from February to April 2010. 239 patients were eligible for the study. There was no difference between the groups suspected for DVT, ACS and AA, but a significant reduction in time for the ABI group (p:0.009), where the median time to decision was reduced from 7 hours and 33 minutes to 4 hours and 38 minutes when POCT was used. Only in the confirmation of ABI the time to action was significantly shorter. Conclusions Fast laboratory answers by POCT in an ED reduce the time to clinical decision significantly for bacterial infections. We suggest further studies which include a sufficient number of patients on deep venous thrombosis, acute appendicitis and acute coronary syndrome.
Wide-scale point-of-care diagnostic systems hold great promise for early detection of cancer at a curable stage of the disease. This review discusses the prospects and challenges of electrochemical biosensors for next-generation cancer diagnostics. Electrochemical biosensors have played an important significant role in the transition towards point-of-care diagnostic devices. Such electrical devices are extremely useful for delivering the diagnostic information in
Background\\/objectives: Most current tests for Neisseria gonorrhoeae and Chlmydia trachomatis require the support of a laboratory, and results are not usually available before the patient has left the clinic. This delay can lead to patients not returning for treatment and may allow further STI transmission to occur. Current rapid point of care (POC) STI tests and the syndromic approach are
P Vickerman; C Watts; M Alary; D Mabey; R W Peeling
Rapid volatile profiling of stool sample headspace was achieved using a combination of short multi-capillary chromatography column (SMCC), highly sensitive heated metal oxide semiconductor sensor and artificial neural network software. For direct analysis of biological samples this prototype offers alternatives to conventional gas chromatography (GC) detectors and electronic nose technology. The performance was compared to an identical instrument incorporating a long single capillary column (LSCC). The ability of the prototypes to separate complex mixtures was assessed using gas standards and homogenized in house ‘standard’ stool samples, with both capable of detecting more than 24 peaks per sample. The elution time was considerably faster with the SMCC resulting in a run time of 10 min compared to 30 min for the LSCC. The diagnostic potential of the prototypes was assessed using 50 C. difficile positive and 50 negative samples. The prototypes demonstrated similar capability of discriminating between positive and negative samples with sensitivity and specificity of 85% and 80% respectively. C. difficile is an important cause of hospital acquired diarrhoea, with significant morbidity and mortality around the world. A device capable of rapidly diagnosing the disease at the point of care would reduce cases, deaths and financial burden.
McGuire, N. D.; Ewen, R. J.; de Lacy Costello, B.; Garner, C. E.; Probert, C. S. J.; Vaughan, K.; Ratcliffe, N. M.
Orally based diagnostic testing is emerging as an alternative, noninvasive method for analyzing a variety of analytes. These analytes include pathogens, antibodies, drugs, and nucleic acids. In the present study we developed a protocol for evaluation of collectors that could be used in orally based, point-of-care diagnostics. A performance comparison was carried out with a number of commercially available collectors,
Carol Holm-Hansen; Gary Tong; Cheryl Davis; William R. Abrams; Daniel Malamud
Measurement of hemoglobin A1c (A1C) has long been accepted as the best indicator of glucose control over time. Assays for A1C use technologies based on either charge differences (high-pressure liquid chromatography) or structure (boronate affinity or immunoassay combined with general chemistry). These technologies are generally employed in expensive laboratory instruments. More recently, A1C technology has been incorporated into point of care (POC) devices, allowing for immediate availability of A1C measurements, greatly facilitating diabetes care in both specialist and general practices. POC A1C tests should have acceptable performance, standardization to national reference, National Glycohemoglobin Standardization Program (NGSP) certification, simple operation without need for costly instrumentation, and Clinical Laboratory Improvement Amendments (CLIA) waiver. CLIA-waived POC technology includes Bio-Rad MicroMat™ II (distributed by Cholestech as GDX™) and the Axis-Shield Afinion,™ both of which utilize boronate affinity. The DCA 2000®+ utilizes combined immunoassay and general chemistry. These instruments cost $1000 to $3000 and require regular maintenance, making them appropriate only for high-volume physician offices. The newly improved A1CNow+™ also utilizes combined immunoassay and general chemistry, but the small, inexpensive, disposable monitor can be used by patients as well as by health care professionals. The new version of A1CNow+ has improved performance through recent introduction of automated solid state chemistry manufacturing, improved fluidics and automated assembly of the test cartridge, error-correcting software, and unitary meter calibration with factory calibration directly to the NGSP reference standard.
Bode, Bruce W.; Irvin, Benjamin R.; Pierce, Jeffrey A.; Allen, Michael; Clark, Annette L.
Measurement of hemoglobin A1c (A1C) has long been accepted as the best indicator of glucose control over time. Assays for A1C use technologies based on either charge differences (high-pressure liquid chromatography) or structure (boronate affinity or immunoassay combined with general chemistry). These technologies are generally employed in expensive laboratory instruments. More recently, A1C technology has been incorporated into point of care (POC) devices, allowing for immediate availability of A1C measurements, greatly facilitating diabetes care in both specialist and general practices. POC A1C tests should have acceptable performance, standardization to national reference, National Glycohemoglobin Standardization Program (NGSP) certification, simple operation without need for costly instrumentation, and Clinical Laboratory Improvement Amendments (CLIA) waiver. CLIA-waived POC technology includes Bio-Rad MicroMat II (distributed by Cholestech as GDX) and the Axis-Shield Afinion, both of which utilize boronate affinity. The DCA 2000(R)+ utilizes combined immunoassay and general chemistry. These instruments cost $1000 to $3000 and require regular maintenance, making them appropriate only for high-volume physician offices. The newly improved A1CNow+ also utilizes combined immunoassay and general chemistry, but the small, inexpensive, disposable monitor can be used by patients as well as by health care professionals. The new version of A1CNow+ has improved performance through recent introduction of automated solid state chemistry manufacturing, improved fluidics and automated assembly of the test cartridge, error-correcting software, and unitary meter calibration with factory calibration directly to the NGSP reference standard. PMID:19885097
Bode, Bruce W; Irvin, Benjamin R; Pierce, Jeffrey A; Allen, Michael; Clark, Annette L
IntroductionThe use of oral anticoagulant therapy is increasing in children. Managing anticoagulant therapy in children presents unique challenges, including poor venous access. The advent of point-of-care (POC) monitoring of anticoagulant therapy offers a potential solution to this challenge. This paper reviews the published literature relating to POC monitoring of oral anticoagulant therapy in children.
Fiona Newall; Mary Bauman
The rapid detection and identification of infectious disease pathogens is a critical need for healthcare in both developed and developing countries. As we gain more insight into the genomic basis of pathogen infectivity and drug resistance, point-of-care nucleic acid testing will likely become an important tool for global health. In this paper, we present an inexpensive, handheld, battery-powered instrument designed to enable pathogen genotyping in the developing world. Our Microfluidic Biomolecular Amplification Reader (µBAR) represents the convergence of molecular biology, microfluidics, optics, and electronics technology. The µBAR is capable of carrying out isothermal nucleic acid amplification assays with real-time fluorescence readout at a fraction of the cost of conventional benchtop thermocyclers. Additionally, the µBAR features cell phone data connectivity and GPS sample geotagging which can enable epidemiological surveying and remote healthcare delivery. The µBAR controls assay temperature through an integrated resistive heater and monitors real-time fluorescence signals from 60 individual reaction chambers using LEDs and phototransistors. Assays are carried out on PDMS disposable microfluidic cartridges which require no external power for sample loading. We characterize the fluorescence detection limits, heater uniformity, and battery life of the instrument. As a proof-of-principle, we demonstrate the detection of the HIV-1 integrase gene with the µBAR using the Loop-Mediated Isothermal Amplification (LAMP) assay. Although we focus on the detection of purified DNA here, LAMP has previously been demonstrated with a range of clinical samples, and our eventual goal is to develop a microfluidic device which includes on-chip sample preparation from raw samples. The µBAR is based entirely around open source hardware and software, and in the accompanying online supplement we present a full set of schematics, bill of materials, PCB layouts, CAD drawings, and source code for the µBAR instrument with the goal of spurring further innovation toward low-cost genetic diagnostics.
Myers, Frank B.; Henrikson, Richard H.; Bone, Jennifer; Lee, Luke P.
The rapid detection and identification of infectious disease pathogens is a critical need for healthcare in both developed and developing countries. As we gain more insight into the genomic basis of pathogen infectivity and drug resistance, point-of-care nucleic acid testing will likely become an important tool for global health. In this paper, we present an inexpensive, handheld, battery-powered instrument designed to enable pathogen genotyping in the developing world. Our Microfluidic Biomolecular Amplification Reader (µBAR) represents the convergence of molecular biology, microfluidics, optics, and electronics technology. The µBAR is capable of carrying out isothermal nucleic acid amplification assays with real-time fluorescence readout at a fraction of the cost of conventional benchtop thermocyclers. Additionally, the µBAR features cell phone data connectivity and GPS sample geotagging which can enable epidemiological surveying and remote healthcare delivery. The µBAR controls assay temperature through an integrated resistive heater and monitors real-time fluorescence signals from 60 individual reaction chambers using LEDs and phototransistors. Assays are carried out on PDMS disposable microfluidic cartridges which require no external power for sample loading. We characterize the fluorescence detection limits, heater uniformity, and battery life of the instrument. As a proof-of-principle, we demonstrate the detection of the HIV-1 integrase gene with the µBAR using the Loop-Mediated Isothermal Amplification (LAMP) assay. Although we focus on the detection of purified DNA here, LAMP has previously been demonstrated with a range of clinical samples, and our eventual goal is to develop a microfluidic device which includes on-chip sample preparation from raw samples. The µBAR is based entirely around open source hardware and software, and in the accompanying online supplement we present a full set of schematics, bill of materials, PCB layouts, CAD drawings, and source code for the µBAR instrument with the goal of spurring further innovation toward low-cost genetic diagnostics. PMID:23936402
Myers, Frank B; Henrikson, Richard H; Bone, Jennifer; Lee, Luke P
In this paper we present the POCEMON platform, a platform aiming to the early prognosis and diagnosis of autoimmune diseases at any point of care, even the primary. The objective of the POCEMON platform is the development of a diagnostic lab-on-chip device based on genomic microarrays of HLA-typing. The POCEMON is going to advance and promote the primary health care
Fanis G. Kalatzis; Themis P. Exarchos; Nikolaos Giannakeas; Sofia Markoula; Elisavet Hatzi; Panagiotis Rizos; Ioannis Georgiou; Dimitrios I. Fotiadis
Interoperability standards, if properly applied to medical system design, have the potential to decrease the cost of point-of-care monitoring systems while better matching systems to patient needs. This paper presents a brief editorial overview of future monitoring environments, followed by a short listing of smart-home and wearable-device efforts. This is followed by a summary of recent efforts in the Medical
Steve Warren; Jianchu Yao; Ryan Schmitz; Jeff Lebak
Perioperative monitoring of blood coagulation is critical to better understand causes of hemorrhage, to guide hemostatic therapies, and to predict the risk of bleeding during the consecutive anesthetic or surgical procedures. Point-of-care (POC) coagulation monitoring devices assessing the viscoelastic properties of whole blood, i.e., thrombelastography, rotation thrombelastometry, and Sonoclot analysis, may overcome several limitations of routine coagulation tests in the
Michael T. Ganter; Christoph K. Hofer
This paper presents the development of a disposable plastic biochip incorporating smart passive microfluidics with embedded on-chip power sources and integrated biosensor array for applications in clinical diagnostics and point-of-care testing. The fully integrated disposable biochip is capable of precise volume control with smart microfluidic manipulation without costly on-chip microfluidic components. The biochip has a unique power source using on-chip
CHONG H. AHN; Jin-Woo Choi; GREGORY BEAUCAGE; JOSEPH H. NEVIN; Jeong-Bong Lee; ANIRUDDHA PUNTAMBEKAR; JAE Y. LEE
Evolving information technology has had profound effects on business operations and the marketplace. The health care services industry, particularly hospitals, clinics, and medical offices, has historically lagged behind other industries in the implementation of comprehensive, integrated, computerized data management tools. Health care reformers are looking to the promises of the information technology "revolution" as a means of improving systemic efficiency and health care quality. This study discusses the impact of informatics, or information technology, on the delivery of health care services. We present the evolution of informatics and the predicted future benefits of integrated computerized patient records and point-of-care systems. PMID:10162811
Montoya, I D; Carlson, J W
We have developed a next generation, miniaturized platform to diagnose disease at the point-of-care using diagnostic magnetic resonance (DMR-3). Utilizing a rapidly growing library of functionalized magnetic nanoparticles, DMR has previously been demonstrated as a versatile tool to quantitatively and rapidly detect disease biomarkers in unprocessed biological samples. A major hurdle for bringing DMR to the point-of-care has been its sensitivity to temperature variation. As an alternative to costly and bulky mechanisms to control temperature, we have implemented an automated feedback system to track and compensate for the temperature drift, which enables reliable and robust DMR measurements in realistic clinical environments (4–50 °C). Furthermore, the new system interfaces with a mobile device to facilitate system control and data sharing over wireless networks. With such features, the DMR-3 platform can function as a self-contained laboratory even in resource-limited, remote settings. The clinical potential of the new system is demonstrated by detecting trace amounts of proteins and as few as 10 bacteria (Staphylococcus aureus) in a short time frame (<30 min).
Issadore, David; Min, Changwook; Liong, Monty; Chung, Jaehoon; Weissleder, Ralph; Lee, Hakho
...develop and implement a new research protocol in the VA. DATES...Conduct the Point-of-Care Research Questionnaire)'' in any...of information technology. Title: Conduct the Point-of-Care Research Questionnaire, VA Form...
Human African trypanosomiasis is a debilitating disease prevalent in rural sub-Saharan Africa. Control of this disease almost exclusively relies on chemotherapy that should be driven by accurate diagnosis, given the unacceptable toxicity of the few available drugs. Unfortunately, the available diagnostics are characterised by low sensitivities due to the inherent low parasitaemia in natural infections. Demonstration of the trypanosomes in body fluids, which is a prerequisite before treatment, often follows complex algorithms. In this paper, we review the available diagnostics and explore recent advances towards development of novel point-of-care diagnostic tests.
Matovu, Enock; Kazibwe, Anne Juliet; Mugasa, Claire Mack; Ndungu, Joseph Mathu; Njiru, Zablon Kithingi
Electronic health records (EHRs) provide clinical learning opportunities through quick and contextual linkage of patient signalment, symptom, and diagnosis data with knowledge resources covering tests, drugs, conditions, procedures, and client instructions. This paper introduces the EHR standards for linkage and the partners-practitioners, content publishers, and software developers-necessary to leverage this possibility in veterinary medicine. The efforts of the American Animal Hospital Association (AAHA) Electronic Health Records Task Force to partner with veterinary practice management systems to improve the use of controlled vocabulary is a first step in the development of standards for sharing knowledge at the point of care. The Veterinary Medical Libraries Section (VMLS) of the Medical Library Association's Task Force on Connecting the Veterinary Health Record to Information Resources compiled a list of resources of potential use at point of care. Resource details were drawn from product Web sites and organized by a metric used to evaluate medical point-of-care resources. Additional information was gathered from questions sent by e-mail and follow-up interviews with two practitioners, a hospital network, two software developers, and three publishers. Veterinarians with electronic records use a variety of information resources that are not linked to their software. Systems lack the infrastructure to use the Infobutton standard that has been gaining popularity in human EHRs. While some veterinary knowledge resources are digital, publisher sites and responses do not indicate a Web-based linkage of veterinary resources with EHRs. In order to facilitate lifelong learning and evidence-based practice, veterinarians and educators of future practitioners must demonstrate to veterinary practice software developers and publishers a clinically-based need to connect knowledge resources to veterinary EHRs. PMID:22023919
Alpi, Kristine M; Burnett, Heidi A; Bryant, Sheila J; Anderson, Katherine M
Dipstick and lateral-flow formats have dominated rapid diagnostics over the last three decades. These formats gained popularity in the consumer markets due to their compactness, portability and facile interpretation without external instrumentation. However, lack of quantitation in measurements has challenged the demand of existing assay formats in consumer markets. Recently, paper-based microfluidics has emerged as a multiplexable point-of-care platform which might transcend the capabilities of existing assays in resource-limited settings. However, paper-based microfluidics can enable fluid handling and quantitative analysis for potential applications in healthcare, veterinary medicine, environmental monitoring and food safety. Currently, in its early development stages, paper-based microfluidics is considered a low-cost, lightweight, and disposable technology. The aim of this review is to discuss: (1) fabrication of paper-based microfluidic devices, (2) functionalisation of microfluidic components to increase the capabilities and the performance, (3) introduction of existing detection techniques to the paper platform and (4) exploration of extracting quantitative readouts via handheld devices and camera phones. Additionally, this review includes challenges to scaling up, commercialisation and regulatory issues. The factors which limit paper-based microfluidic devices to become real world products and future directions are also identified. PMID:23652632
Yetisen, Ali Kemal; Akram, Muhammad Safwan; Lowe, Christopher R
Control of blood glucose (BG) in an acceptable range is a major therapy target for diabetes patients in both the hospital and outpatient environments. This review focuses on the state of point-of-care (POC) glucose monitoring and the accuracy of the measurement devices. The accuracy of the POC glucose monitor depends on device methodology and other factors, including sample source and collection and patient characteristics. Patient parameters capable of influencing measurements include variations in pH, blood oxygen, hematocrit, changes in microcirculation, and vasopressor therapy. These elements alone or when combined can significantly impact BG measurement accuracy with POC glucose monitoring devices (POCGMDs). In general, currently available POCGMDs exhibit the greatest accuracy within the range of physiological glucose levels but become less reliable at the lower and higher ranges of BG levels. This issue raises serious safety concerns and the importance of understanding the limitations of POCGMDs. This review will discuss potential interferences and shortcomings of the current POCGMDs and stress when these may impact the reliability of POCGMDs for clinical decision-making.
Rebel, Annette; Rice, Mark A.; Fahy, Brenda G.
BACKGROUND: We assessed point-of-care device specifications and needs for pathogen detection in urgent care, emergencies, and disasters. METHODS: We surveyed American Association for Clinical Chemistry members and compared responses to those of disaster experts. Online SurveyMonkey questions covered performance characteristics, device design, pathogen targets, and other specifications. RESULTS: For disasters, respondents preferred direct sample collection with a disposable test cassette that stores biohazardous material (P<0.001). They identified methicillin-resistant Staphylococcus aureus, Salmonella typhi, Vibrio cholerae, Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae as high priority pathogens. First responders were deemed the professional group who should perform POC testing in disasters (P<0.001). CONCLUSIONS: Needs assessment now is requisite for competitive funding, so the results in this report will be useful to investigators preparing grant applications. Point-of-care devices used in disasters should address the needs of first responders, who give high priority to contamination-free whole-blood sampling, superior performance pathogen detection, and HIV-1/2 blood donor screening. There was surprising concordance of preferences among different professional groups, which presages formulation of global consensus guidelines to assist high impact preparedness. PMID:23049471
Kost, Gerald J; Mecozzi, Daniel M; Brock, T Keith; Curtis, Corbin M
Background We assessed point-of-care device specifications and needs for pathogen detection in urgent care, emergencies, and disasters. Methods We surveyed American Association for Clinical Chemistry members and compared responses to those of disaster experts. Online SurveyMonkey questions covered performance characteristics, device design, pathogen targets, and other specifications. Results For disasters, respondents preferred direct sample collection with a disposable test cassette that stores biohazardous material (P<0.001). They identified methicillin-resistant Staphylococcus aureus, Salmonella typhi, Vibrio cholerae, Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae as high priority pathogens. First responders were deemed the professional group who should perform POC testing in disasters (P<0.001). Conclusions Needs assessment now is requisite for competitive funding, so the results in this report will be useful to investigators preparing grant applications. Point-of-care devices used in disasters should address the needs of first responders, who give high priority to contamination-free whole-blood sampling, superior performance pathogen detection, and HIV-1/2 blood donor screening. There was surprising concordance of preferences among different professional groups, which presages formulation of global consensus guidelines to assist high impact preparedness.
Kost, Gerald J.; Mecozzi, Daniel M.; Brock, T. Keith; Curtis, Corbin M.
Clinical testing of human blood requires adherence to a number of regulatory standards, including maintaining a temperature that is representative of the human body (e.g. 37 C). The economics of private and public healthcare drives blood assays to be conducted using low cost, disposable assay devices that also eliminate the possibility of cross contamination. Unfortunately, the materials that meet the economic and disposable constraints of the marketplace are thermal insulators, not ideal for rapid heating. We present a novel means of optically heating blood samples in plastic assay devices within a time period suitable for point-of-care use. The novel approach uses LED's in the red portion of the visible spectrum. The lower absorption of optical radiation in the visible spectrum enables the absorption of energy deep into the assay device. This produces even heating, avoiding the gradients that can occur by surface heating (conduction) or surface absorption (highly absorbing wavelengths). Analytical and computational models will be discussed. A specific application to a point-of-care blood assay instrument will be reviewed. In this application, optical heating was achieved using a small array of high brightness LED's. Experimental results will be discussed. The experimental results with this instrument validated the predictions.
Catanzaro, Brian E.; Hill, Ted; Hankins, Steve; Gandola, Kent
Respiratory infections, particularly those caused by influenza viruses, represent the third-most important cause of death in the world due to infectious diseases. Nevertheless, despite the enormous publicity attracted by epidemics due to these viruses, laboratory diagnosis, documentation and recording of respiratory diseases is still unsatisfactory. Available diagnostic tests capable of providing results rapidly are either limited and insufficiently sensitive or highly sensitive and specific but insufficiently rapid. Considerable investment and research efforts have been made towards the development of new diagnostics for influenza A and B viruses and the Xpert(®) Flu assay (Cepheid(®), CA, USA) has emerged as one of the most promising. In this article, we review current knowledge of the Xpert Flu test, discuss its potential value as a point-of-care test and outline the potential leads for future development. PMID:24707995
Salez, Nicolas; Nougairede, Antoine; Ninove, Laetitia; Zandotti, Christine; de Lamballerie, Xavier; Charrel, Rémi N
Context.-Point-of-care glucose (POCG) testing on capillary blood specimens is central to maintaining glycemic control in patients with diabetes. Although there are known performance issues with POCG methods, especially for maintaining tight glucose control, there is little information about the accuracy of results in the critical ranges that may involve life-threatening conditions. Objectives.-To evaluate the reliability of POCG measurements in critical, high (>600 mg/dL) and low (<40 mg/dL) ranges. Design.-One-year retrospective analysis of POCG (ACCU-CHEK glucose meter, Roche Diagnostics Corporation, Indianapolis, Indiana) results for routine patient care were obtained. The frequency and accuracy of repeat testing after critical POCG results was analyzed. A convenience sample of noncritical capillary POCG measurements retested on venous blood specimens by another point-of-care device (RAPIDPoint 405 analyzer, Siemens Medical Solutions USA, Malvern, Pennsylvania) was also evaluated. Results.-Critical values were observed in 2.4 per 1000 POCG tests (256 of 105,928; 0.24%), with the highest rate (76 of 2289; 3.32%) from the emergency department. Twice as many critical high values as critical low values were seen. Nearly 80% of critical POCG tests (204 of 256) were repeated within 10 minutes. Of these 204 repeat measurements, 112 (54.9%) met accuracy criteria (±15 mg/dL of low and ±20% of high initial values). Accuracy was significantly higher when retesting was performed on the same meter or by the same operator (P ? .05). Comparison of capillary and venous POCG testing of noncritical results showed no significant difference (P = .95), with 89.8% (125 of 139) meeting accuracy criteria. Conclusions.-POCG measurements in the critical range are frequently erroneous, which is likely caused by preanalytic factors associated with sampling capillary blood. POCG testing practices should include retesting to confirm critical results. PMID:24978924
Schifman, Ron B; Nguyen, Tan T; Page, Susan T
Emerging molecular technologies to diagnose infectious diseases at the point at which care is delivered have the potential to save many lives in developing countries where access to laboratories is poor. Molecular tests are needed to improve the specificity of syndromic management, monitor progress towards disease elimination and screen for asymptomatic infections with the goal of interrupting disease transmission and preventing long-term sequelae. In simplifying laboratory-based molecular assays for use at point-of-care, there are inevitable compromises between cost, ease of use and test performance. Despite significant technological advances, many challenges remain for the development of molecular diagnostics for resource-limited settings. There needs to be more advocacy for these technologies to be applied to infectious diseases, increased efforts to lower the barriers to market entry through streamlined and harmonized regulatory approaches, faster policy development for adoption of new technologies and novel financing mechanisms to enable countries to scale up implementation. PMID:24784765
Peeling, Rosanna W; McNerney, Ruth
A CD4 T-lymphocyte count determines eligibility for antiretroviral therapy (ART) with patients recently diagnosed with HIV and also monitors the efficacy of ART treatment thereafter. ART slows the progression of HIV to AIDS. In the developing world, CD4 tests are often performed in centralized laboratories, typically in urban areas. The expansion of ART programs into rural areas has created a need for rapid CD4 counting as logistical barriers can delay the timely dissemination of test results and affect patient care through delay in intervention or loss of follow-up care. CD4 measurement at the point-of-care (POC) in rural areas could help facilitating ART and monitoring of treatment. This review highlights recent technology developments with applications towards determining CD4 counts at the POC.
Boyle, David S.; Hawkins, Kenneth R.; Steele, Matthew S.; Singhal, Mitra; Cheng, Xuanhong
Medical doctors require high quality clinical evidence at the point of care in order to support their decision-making. Presentation of clinical evidence on handheld devices, and in a timely fashion, requires an integrated approach to documentation and ergonomic design. This paper reports on results from The Bringing Evidence to the Point of Care Project at the University of Toronto, concerning
Michelle Graham; Mark H. Chignell; Harumi Takeshita
In point-of-care situations, use of mobile devices may demand much of the physicians attention and may disturb the communication with the patient. By using minimal attention user interface design and context awareness, attention theft from mobile devices at point-of-care can be reduced.
Ole Andreas Alsos
This paper compares the usability of some location and token-based interaction techniques for systems that provide point-of-care\\u000a access to medical information. The investigation is based around a scenario from clinical work—administration of medicine to patients. Four interaction techniques that match the scenario are identified. We demonstrate how these techniques can be concretized\\u000a through functional prototypes. The prototypes were tested with
Yngve Dahl; Dag Svanæs
Background: Creatine kinase MB (CK-MB), and cardiac troponin I (cTnI) are important biomarkers for the diagnosis and rule-out of acute myocardial infarction (AMI) of patients who presented to the emergency department (ED) with chest pain. With new rapid ED assessment protocols, there is increasing pressure to produce results with a short turnaround time (TAT), and point-of-care (POC) testing is one
Alan H. B Wu; Andrew Smith; Robert H Christenson; MaryAnn M Murakami; Fred S Apple
Accurate and inexpensive point-of-care (POC) tests are urgently needed to control sexually transmitted infection epidemics, so that patients can receive immediate diagnoses and treatment. Current POC assays for Chlamydia trachomatis and Neisseria gonorrhoeae perform inadequately and require better assays. Diagnostics for Trichomonas vaginalis rely on wet preparation, with some notable advances. Serological POC assays for syphilis can impact resource-poor settings, with many assays available, but only one available in the U.S. HIV POC diagnostics demonstrate the best performance, with excellent assays available. There is a rapid assay for HSV lesion detection; but no POC serological assays are available. Despite the inadequacy of POC assays for treatable bacterial infections, application of technological advances offers the promise of advancing POC diagnostics for all sexually transmitted infections. PMID:24484215
Gaydos, Charlotte; Hardick, Justin
Tuberculosis (TB) remains one of the most devastating infectious diseases and its eradication is still unattainable given the limitations of current technologies for diagnosis, treatment and prevention. The World Health Organization’s goal to eliminate TB globally by 2050 remains an ongoing challenge as delayed diagnosis and misdiagnosis of TB continues to fuel the worldwide epidemic. Despite considerable improvements in diagnostics for the last few decades, a simple and effective point-of-care TB diagnostic test is yet not available. Here, we review the current assays used for TB diagnosis, and highlight the recent advances in nanotechnology and microfluidics that potentially enable new approaches for TB diagnosis in resource-constrained settings.
Wang, ShuQi; Inci, Fatih; De Libero, Gennaro; Singhal, Amit; Demirci, Utkan
Accurate and inexpensive point-of-care (POC) tests are urgently needed to control sexually transmitted infection (STI) epidemics, so that patients can receive immediate diagnoses and treatment. Current POC assays for Chlamydia trachomatis and Neisseria gonorrhoeae perform inadequately and require better assays. Diagnostics for Trichomonas vaginalis rely on wet preparation, with some notable advances. Serological POC assays for syphilis can impact resource-poor settings, with many assays available, but only one available in the U.S. HIV POC diagnostics demonstrate the best performance, with excellent assays available. There is a rapid assay for HSV lesion detection; but no POC serological assays are available. Despite the inadequacy of POC assays for treatable bacterial infections, application of technological advances offers the promise of advancing POC diagnostics for all STIs.
Gaydos, Charlotte; Hardick, Justin
Digital nucleic acid amplification provides unprecedented opportunities for absolute nucleic acid quantification by counting of single molecules. This technique is useful for molecular genetic analysis in cancer, stem cell, bacterial, non-invasive prenatal diagnosis in which many biologists are interested. This paper describes a self-priming compartmentalization (SPC) microfluidic chip platform for performing digital loop-mediated amplification (LAMP). The energy for the pumping is pre-stored in the degassed bulk PDMS by exploiting the high gas solubility of PDMS; therefore, no additional structures other than channels and reservoirs are required. The sample and oil are sequentially sucked into the channels, and the pressure difference of gas dissolved in PDMS allows sample self-compartmentalization without the need for further chip manipulation such as with pneumatic microvalves and control systems, and so on. The SPC digital LAMP chip can be used like a 384-well plate, so, the world-to-chip fluidic interconnections are avoided. The microfluidic chip contains 4 separate panels, each panel contains 1200 independent 6 nL chambers and can be used to detect 4 samples simultaneously. Digital LAMP on the microfluidic chip was tested quantitatively by using ?-actin DNA from humans. The self-priming compartmentalization behavior is roughly predictable using a two-dimensional model. The uniformity of compartmentalization was analyzed by fluorescent intensity and fraction of volume. The results showed that the feasibility and flexibility of the microfluidic chip platform for amplifying single nucleic acid molecules in different chambers made by diluting and distributing sample solutions. The SPC chip has the potential to meet the requirements of a general laboratory: power-free, valve-free, operating at isothermal temperature, inexpensive, sensitive, economizing labour time and reagents. The disposable analytical devices with appropriate air-tight packaging should be useful for point-of-care, and enabling it to become one of the common tools for biology research, especially, in point-of-care testing. PMID:22986619
Zhu, Qiangyuan; Gao, Yibo; Yu, Bingwen; Ren, Hao; Qiu, Lin; Han, Sihai; Jin, Wei; Jin, Qinhan; Mu, Ying
The tissue fluorescence gives the response of light emitting molecule signature, and characterizes the cell composition and peculiarities of metabolism. Both are useful for the biomedical diagnostics, as reported in previous our and others works. The present work demonstrates the results of application of laser excited autofluorescence for diagnostics of pathology in genital tissues, and the feasibility for the bedside at ``point of care--off lab'' application. A portable device using the USB spectrophotometer, micro laser (355 nm Nd:YAG, 0,5 ns pulse, repetition rate 10 kHz, output power 15 mW), three channel optical fiber and computer with diagnostic program was designed and ready for clinical trial to be used for cytology and biopsy specimen on site diagnostics, and for the endoscopy/puncture procedures. The biopsy and cytology samples, as well as intervertebral disc specimen were evaluated by pathology experts and the fluorescence spectra were investigated in the fresh and preserved specimens. The spectra were recorded in the spectral range 350-900 nm. At the initial stage the Gaussian components of spectra were found and the Mann-Whitney test was used for the groups' differentiation and the spectral regions for optimal diagnostics purpose were found. Then a formal dividing of spectra in the components or the definite width bands, where the main difference of the different group spectra was observed, was used to compare these groups. The ROC analysis based diagnostic algorithms were created for medical prognosis. The positive prognostic values and negative prediction values were determined for cervical Liquid PAP smear supernatant sediment diagnosis of being Cervicitis and Norma versus CIN2+. In a case of intervertebral disc the analysis allows to get the additional information about the disc degeneration status. All these results demonstrated an efficiency of the proposed procedure and the designed device could be tested at the point-of-care site or for intervertebral disc operations.
Vaitkuviene, A.; G?gžna, V.; Varanius, D.; Vaitkus, J.
Early efforts to use point-of-care clinical decision support (CDS) were limited to the use of prompts and reminders, which improved test ordering but not intermediate outcomes of care such as glucose, blood pressure, or lipid levels. More sophisticated diabetes CDS tools are now available that use electronic medical record data to provide patient-specific advice on medication use based on previous treatment, distance from goal, and other clinical data. These tools have shown modest but significant improvement in glucose and blood pressure control. Promising next-generation developments will include prioritizing clinical actions that have maximum benefit to a given patient at the point of care and developing effective methods to communicate CDS information to patients to better incorporate patient preferences in care decisions.
O'Connor, Patrick J.; Desai, Jay; Butler, John; Kharbanda, Elyse; Sperl-Hillen, JoAnn M.
Question: Can a mobile optimized subject guide facilitate medical student access to mobile point-of-care tools? Setting: The guide was created at a library at a research-intensive university with six teaching hospital sites. Objectives: The team created a guide facilitating medical student access to point-of-care tools directly on mobile devices to provide information allowing them to access and set up resources with little assistance. Methods: Two librarians designed a mobile optimized subject guide for medicine and conducted a survey to test its usefulness. Results: Web analytics and survey results demonstrate that the guide is used and the students are satisfied. Conclusion: The library will continue to use the subject guide as its primary means of supporting mobile devices. It remains to be seen if the mobile guide facilitates access for those who do not need assistance and want direct access to the resources. Internet access in the hospitals remains an issue.
Boruff, Jill T; Bilodeau, Edward
Background Prior studies show that lactate is a useful prognostic marker in sepsis. Objective To study the feasibility and accuracy of a point-of-care (POC) analyzer capable of performing bedside serum lactate measurements; and to determine if other measurements (pH, base excess) are predictive of mortality. Methods: Design: prospective cohort study of adult (age 18 years or older) Emergency Department (ED) patients with suspected infection during the study period of May 2006 through March 2007. Setting A 55,000-annual-visit urban tertiary care ED. Intervention A point-of-care device (i-STAT, Abbott Point of Care Inc., Princeton, NJ) was deployed using a standardized training and quality assurance process. Using POC testing, we measured serum lactate, pH, and base excess, as well as concomitant lactate measurement via a central laboratory. Statistics Area under the curve (AUC) for receiver operator characteristic curve, Bland-Altman statistics along with a correlation coefficient, and relative risk with 95% confidence intervals reported. Results There were 699 patients enrolled, of whom 34 (4.9%) died. The AUCs for mortality prediction were: POC lactate 0.72, laboratory lactate 0.70, pH measurement 0.60, and base excess 0.60. Bland-Altman showed that POC lactate was, on average, 0.32 (95% confidence interval ?0.35– 0.98) lower than laboratory lactate, with agreement kappa = 0.97. Conclusions A point-of-care testing device provides a reliable and feasible way to measure serum lactate at the bedside. The pH and base excess were less helpful.
Shapiro, Nathan I.; Fisher, Christopher; Donnino, Michael; Cataldo, Lauren; Tang, Aimee; Trzeciak, Stephen; Horowitz, Gary; Wolfe, Richard E.
Rapid, sensitive and specific diagnostic assays play an indispensable role in determination of HIV infection stages and evaluation of efficacy of antiretroviral therapy. Recently, our laboratory developed a sensitive Europium nanoparticle-based microtiter-plate immunoassay capable of detecting target analytes at subpicogram per milliliter levels without the use of catalytic enzymes and signal amplification processes. Encouraged by its sensitivity and simplicity, we continued to miniaturize this assay to a microchip platform for the purpose of converting the benchtop assay technique to a point-of-care test. It was found that detection capability of the microchip platform could be readily improved using Europium nanoparticle probes. We were able to routinely detect 5pg/mL (4.6 attomoles) of HIV-1 p24 antigen at a signal-to-blank ratio of 1.5, a sensitivity level reasonably close to that of microtiter-plate Europium nanoparticle assay. Meanwhile, use of the microchip platform effectively reduced sample/reagent consumption 4.5 fold and shortened total assay time 2 fold in comparison with microtiter plate assays. Complex matrix substance in plasma negatively affected the microchip assays and the effects could be minimized by diluting the samples before loading. With further improvements in sensitivity, reproducibility, usability, assay process simplification, and incorporation of portable time-resolved fluorescence reader, Europium nanoparticle immunoassay technology could be adapted to meet the challenges of point-of-care diagnosis of HIV or other health-threatening pathogens at bedside or in resource-limited settings. PMID:24880655
Liu, Jikun; Du, Bingchen; Zhang, Panhe; Haleyurgirisetty, Mohan; Zhao, Jiangqin; Ragupathy, Viswanath; Lee, Sherwin; DeVoe, Don L; Hewlett, Indira K
Objective Trichomonas vaginalis infection is the most prevalent treatable sexually transmitted infection (STI) in the world. An accurate point-of-care (PoC) molecular test would enable patients to be tested and treated for T vaginalis in a single visit to the genitourinary medicine clinic, community STI clinic, pharmacy or doctor’s office. In this report, we describe a rapid prototype assay for T vaginalis designed for use in conjunction with the Atlas io PoC platform, and initial verification of its performance using 90 clinical samples. Methods A rapid prototype T vaginalis assay was designed. The test, featuring novel electrochemical endpoint detection, used a multi-copy region of the T vaginalis genome as the assay target. Ninety clinical vaginal swab samples were used to verify the performance of the prototype assay. Results The assay demonstrated a sensitivity and specificity of 95.5% (42/44) and 95.7% (44/46), respectively, when tested using clinical samples. Assay inclusivity was demonstrated for a number of geographically diverse T vaginalis isolates, and the test showed no cross-reactivity with either human DNA or a panel of DNAs isolated from common cross-reactants. Conclusions The sensitivity and specificity achieved using this prototype assay is comparable with that achieved for existing central laboratory nucleic acid amplification tests used for screening patients for T vaginalis.
Pearce, David M; Styles, David N; Hardick, Justin P; Gaydos, Charlotte A
OBJECTIVES To describe Wellness Initiative of the Northland (WIN) screening events; present participant results from those events; discuss the benefits of pharmacist-conducted, community-based point-of-care (POC) testing to medically underserved patients and to the profession of pharmacy; and describe logistical considerations in launching disease screening services. SETTING Pharmacist-led community health fairs in a variety of settings, including shopping malls, churches, community pharmacies, senior residence facilities, critical-access hospitals, and clinics. PRACTICE DESCRIPTION Disease screenings for economically disadvantaged residents of northeastern Minnesota and northwest Wisconsin, held between 2005 and 2012, through WIN. PRACTICE INNOVATION Mobile POC screenings for dyslipidemia, diabetes, hypertension, and osteoporosis. MAIN OUTCOME MEASURE Percentage of screenings with out-of-range readings. RESULTS Since 2005, WIN screenings have served more than 2,000 individuals, providing 4,152 POC screenings. Out-of-range readings were obtained for 40.3% of fingerstick cholesterol tests, 24.8% of fingerstick blood glucose tests, 24.3% of blood pressure tests, and 38.7% of quantitative ultrasound heel bone density readings. CONCLUSION Community-conducted POC testing functions both as an important public health service and a mechanism by which pharmacists and student pharmacists can become involved in civic engagement. PMID:24407741
Palombi, Laura C; Bastianelli, Karen; Stratton, Timothy
Chemiluminescence, i.e. the emission of light from a chemical reaction, offers interesting opportunities for developing point-of-care biosensors. However, commercially available systems are expensive, bulky, and primarily addressed to laboratory usage. The goal of this paper is to present a novel work related to the design and experimental validation of a point-of-care device for cancer marker detection in human serum. The
Pasquale Grosso; Sandro Carrara; Claudio Stagni; Luca Benini
Informatics related to point-of-care devices denotes the ability to translate stand-alone biological data into meaningful information that can be interpreted to enable and support users in taking the most appropriate steps to aid in managing their health. This paper considers small point-of-care devices used outside healthcare environments, and presents glucometers as an example. The paper seeks to evaluate the current
O. Adeogun; A. Tiwari; J. R. Alcock
The use of in vitro diagnostic devices is transitioning from the laboratory to the primary care setting to address early disease detection needs. Time critical viral diagnoses are often made without support due to the experimental time required in today's standard tests. Available rapid point of care (POC) viral tests are less reliable, requiring a follow-on confirmatory test before conclusions can be drawn. The development of a reliable POC viral test for the primary care setting would decrease the time for diagnosis leading to a lower chance of transmission and improve recovery. The single particle interferometric reflectance imaging sensor (SP-IRIS) has been shown to be a sensitive and specific-detection platform in serum and whole blood. This paper presents a step towards a POC viral assay through a SP-IRIS prototype with automated data acquisition and analysis and a simple, easy-to-use software interface. Decreasing operation complexity highlights the potential of SP-IRIS as a sensitive and specific POC diagnostic tool. With the integration of a microfluidic cartridge, this automated instrument will allow an untrained user to run a sample-to-answer viral assay in the POC setting. PMID:24271115
Reddington, Alexander P; Trueb, Jacob T; Freedman, David S; Tuysuzoglu, Ahmet; Daaboul, George G; Lopez, Carlos A; Karl, W Clem; Connor, John H; Fawcett, Helen; Ünlu, M Selim
The use of in vitro diagnostic devices is transitioning from the laboratory to the primary care setting to address early disease detection needs. Time critical viral diagnoses are often made without support due to the experimental time required in today’s standard tests. Available rapid point of care (POC) viral tests are less reliable, requiring a follow-on confirmatory test before conclusions can be drawn. The development of a reliable POC viral test for the primary care setting would decrease the time for diagnosis leading to a lower chance of transmission and improve recovery. The single particle interferometric reflectance imaging sensor (SP-IRIS) has been shown to be a sensitive and specific-detection platform in serum and whole blood. This paper presents a step towards a POC viral assay through a SP-IRIS prototype with automated data acquisition and analysis and a simple, easy-to-use software interface. Decreasing operation complexity highlights the potential of SP-IRIS as a sensitive and specific POC diagnostic tool. With the integration of a microfluidic cartridge, this automated instrument will allow an untrained user to run a sample-to-answer viral assay in the POC setting.
Reddington, Alexander P.; Trueb, Jacob T.; Freedman, David S.; Tuysuzoglu, Ahmet; Daaboul, George G.; Lopez, Carlos A.; Karl, W. Clem; Connor, John H.; Fawcett, Helen; Unlu, M. Selim
Objective Respiratory tract infections are the most common indication for antibiotic prescribing in primary care. The value of clinical findings in lower respiratory tract infection (LRTI) is known to be overrated. This study aimed to determine the independent influence of a point of care test (POCT) for C-reactive protein (CRP) on the prescription of antibiotics in patients with acute cough or symptoms suggestive of LRTI, and how symptoms and chest findings influence the decision to prescribe when the test is and is not used. Design Prospective observational study of presentation and management of acute cough/LRTI in adults. Setting Primary care research networks in Norway, Sweden, and Wales. Subjects Adult patients contacting their GP with symptoms of acute cough/LRTI. Main outcome measures Predictors of antibiotic prescribing were evaluated in those tested and those not tested with a POCT for CRP using logistic regression and receiver operating characteristic (ROC) curve analysis. Results A total of 803 patients were recruited in the three networks. Among the 372 patients tested with a POCT for CRP, the CRP value was the strongest independent predictor of antibiotic prescribing, with an odds ratio (OR) of CRP ? 50 mg/L of 98.1. Crackles on auscultation and a patient preference for antibiotics perceived by the GP were the strongest predictors of antibiotic prescribing when the CRP test was not used. Conclusions The CRP result is a major influence in the decision whether or not to prescribe antibiotics for acute cough. Clinicians attach less weight to discoloured sputum and abnormal lung sounds when a CRP value is available. CRP testing could prevent undue reliance on clinical features that poorly predict benefit from antibiotic treatment.
Jakobsen, Kristin Alise; Melbye, Hasse; Kelly, Mark J.; Ceynowa, Christina; Molstad, Sigvard; Hood, Kerenza; Butler, Christopher C.
The translation of salivary alpha-amylase (sAA) to the ambulatory assessment of stress hinges on the development of technologies capable of speedy and accurate reporting of sAA levels. Here, we describe the developmental validation and usability testing of a point-of-care, colorimetric, sAA biosensor. A disposable test strip allows for streamlined sample collection and a corresponding hand-held reader with integrated analytic capabilities permits rapid analysis and reporting of sAA levels. Bioanalytical validation utilizing saliva samples from 20 normal subjects indicates that, within the biosensor’s linear range (10–230 U/ml), its accuracy (R2 = 0.989), precision (CV < 9%), and measurement repeatability (range ?3.1% to + 3.1%) approach more elaborate laboratory-based, clinical analyzers. The truncated sampling-reporting cycle (< 1 minute) and the excellent performance characteristics of the biosensor has the potential to take sAA analysis out of the realm of dedicated, centralized laboratories and facilitate future sAA biomarker qualification studies.
Shetty, Vivek; Zigler, Corwin; Robles, Theodore F.; Elashoff, David; Yamaguchi, Masaki
Background To date, the use of traditional nucleic acid amplification tests (NAAT) for detection of HIV-1 DNA or RNA has been restricted to laboratory settings due to time, equipment, and technical expertise requirements. The availability of a rapid NAAT with applicability for resource-limited or point-of-care (POC) settings would fill a great need in HIV diagnostics, allowing for timely diagnosis or confirmation of infection status, as well as facilitating the diagnosis of acute infection, screening and evaluation of infants born to HIV-infected mothers. Isothermal amplification methods, such as reverse-transcription, loop-mediated isothermal amplification (RT-LAMP), exhibit characteristics that are ideal for POC settings, since they are typically quicker, easier to perform, and allow for integration into low-tech, portable heating devices. Methodology/Significant Findings In this study, we evaluated the HIV-1 RT-LAMP assay using portable, non-instrumented nucleic acid amplification (NINA) heating devices that generate heat from the exothermic reaction of calcium oxide and water. The NINA heating devices exhibited stable temperatures throughout the amplification reaction and consistent amplification results between three separate devices and a thermalcycler. The performance of the NINA heaters was validated using whole blood specimens from HIV-1 infected patients. Conclusion The RT-LAMP isothermal amplification method used in conjunction with a chemical heating device provides a portable, rapid and robust NAAT platform that has the potential to facilitate HIV-1 testing in resource-limited settings and POC.
Curtis, Kelly A.; Rudolph, Donna L.; Nejad, Irene; Singleton, Jered; Beddoe, Andy; Weigl, Bernhard; LaBarre, Paul; Owen, S. Michele
Abstract Background: In recent years, several selectively acting anticoagulants, including the direct thrombin inhibitors (DTI; argatroban, dabigatran) and the factor Xa inhibitors (rivaroxaban, apixaban, fondaparinux), have been developed. With their clinical application increasing, it is of interest to evaluate their interference with classical haemostaseological point-of-care tests. Additionally, the effect of the investigated anticoagulants on platelet function tests will come increasingly more into focus for monitoring not only hereditary platelet dysfunction, but also antiplatelet therapy. Methods: Blood samples from healthy volunteers were spiked with therapeutic and supratherapeutic concentrations of the drugs listed above and investigated with regard to their effects on the following POCTs: activated clotting time (ACT), thromboelastometry with ROTEM®, PFA® and Multiplate®. Light-transmission aggregometry (LTA) was used for a platelet function assay. Results: At supratherapeutic concentrations, ACT and ROTEM® analysis were always influenced after administration of the drugs listed above (except fondaparinux in EXTEM-CT). Therapeutic concentrations showed differential effects on these assays. LTA measurements revealed a distinct decrease in ?-thrombin-induced platelet aggregation for both DTIs (therapeutic and supratherapeutic concentrations), while argatroban reduced platelet function in supratherapeutic concentrations. None of the drugs seemed to have any influence on PFA® or Multiplate®. Conclusions: Selective thrombin and factor Xa inhibitors exhibit distinct effects on POCTs and platelet function tests. This must be considered in assessing assay results when taking medical decisions. PMID:24406289
Eller, Thomas; Busse, Jessica; Dittrich, Marcus; Flieder, Tobias; Alban, Susanne; Knabbe, Cornelius; Birschmann, Ingvild
This study compares four different activated clotting time (ACT) point-of-care (POC) testing systems used at our institution for the management of patients undergoing heparin therapy. We evaluated these systems under identical conditions to determine their accuracy, reproducibility, ease of use, and cost. Two separate testing stations containing four ACT systems were used. The testing order was randomized for every sample and performed by two trained individuals. Samples of fresh heparinized whole blood were taken at regular intervals and distributed to each station. Each operator tested 50 samples, totaling 400 ACT tests. The ACT value was significantly affected by the type of machine used at both stations 1 and 2 (p < .001). Compared with all systems, the Medtronic ACT Plus Automated Coagulation Timer System (ACT Plus) resulted in the most consistent ACT values (median = 171, Interquartile Range (IQR): 169-175) and least variability (172.17 +/- 5.24). The Hemochron Signature Elite Whole Blood Microcoagulation System had the most variability (221.10 +/- 14.78) and yielded consistently higher ACT values (median = 220, IQR: 210-229.5) compared with other systems. The ACT values reported by the i-STAT Handheld and Test Cartridge Blood Analysis System (153.30 +/- 7.87) were consistently lower (median = 154, IQR: 147-161) in comparison to the ACT Plus and Medtronic HMS Plus Hemostasis Management System (180.60 +/- 7.60, median = 181, IQR: 175-186). There was no statistical difference in results between the two testing sites (p > .05) or the operators (p > .05). The significant finding of this study was the affect each system has on the ACT value. This investigation demonstrates the variability that exists among different ACT monitoring systems at our institution. The discrepant variation in ACT values that exists with the Hemochron system questions the reliability of its use in the management of patients undergoing heparin therapy. PMID:22730859
Ojito, Jorge W; Hannan, Robert L; Burgos, Michelle Moore; Lim, Hyunsoo; Huynh, Monique; Velis, Evelio; Arocha, Marino; Tirotta, Christopher F; Burke, Redmond P
Background Clinical microbiology may direct decisions regarding hospitalization, isolation and anti-infective therapy, but it is not effective at the time of early care. Point-of-care (POC) tests have been developed for this purpose. Methods and Findings One pilot POC-lab was located close to the core laboratory and emergency ward to test the proof of concept. A second POC-lab was located inside the emergency ward of a distant hospital without a microbiology laboratory. Twenty-three molecular and immuno-detection tests, which were technically undemanding, were progressively implemented, with results obtained in less than four hours. From 2008 to 2010, 51,179 tests yielded 6,244 diagnoses. The second POC-lab detected contagious pathogens in 982 patients who benefited from targeted isolation measures, including those undertaken during the influenza outbreak. POC tests prevented unnecessary treatment of patients with non-streptococcal tonsillitis (n?=?1,844) and pregnant women negative for Streptococcus agalactiae carriage (n?=?763). The cerebrospinal fluid culture remained sterile in 50% of the 49 patients with bacterial meningitis, therefore antibiotic treatment was guided by the molecular tests performed in the POC-labs. With regard to enterovirus meningitis, the mean length-of-stay of infected patients over 15 years old significantly decreased from 2008 to 2010 compared with 2005 when the POC was not in place (1.43±1.09 versus 2.91±2.31 days; p?=?0.0009). Altogether, patients who received POC tests were immediately discharged nearly thrice as often as patients who underwent a conventional diagnostic procedure. Conclusions The on-site POC-lab met physicians' needs and influenced the management of 8% of the patients that presented to emergency wards. This strategy might represent a major evolution of decision-making regarding the management of infectious diseases and patient care.
Cohen-Bacrie, Stephan; Ninove, Laetitia; Nougairede, Antoine; Charrel, Remi; Richet, Herve; Minodier, Philippe; Badiaga, Sekene; Noel, Guilhem; La Scola, Bernard; de Lamballerie, Xavier; Drancourt, Michel; Raoult, Didier
In this article, a rapid, sensitive, and disposable microfluidic immunosensor is presented for point-of-care (POC) testing and clinical diagnosis. For the first time, the blocking process is eliminated from a microfluidic heterogeneous immunoassay by using protein A functionalized polydimethylsiloxane microchannels. The nonspecific binding of the assay is maintained around the chip background level by using a pair of antibodies with different affinity to protein A under optimized experimental conditions. C-reactive protein (CRP), a biomarker for inflammation and cardiovascular disease risk assessment, is selected as a model analyte to demonstrate the sensitivity of this blocking-free microfluidic heterogeneous immunoassay. A four parameter logistic function is used to model and assess the data. The limit of detection obtained is 0.54 ?g/mL, which is lower than the cut-off value for clinical diagnosis. The overall assay is completed in 5 min. The protein A modified PDMS chips wet-stored at 4°C can maintain biofunctionality up to 14 months. The developed blocking-free microfluidic heterogeneous immunoassay will immediately provide benefits to most immunosensing microdevices targeted for POC diagnostics by shortening analysis time, simplifying fluid transportation, reducing sample consumption, and lowering waste generation. PMID:21286818
Li, Peng; Sherry, Alexander J; Cortes, Jairo A; Anagnostopoulos, Constantine; Faghri, Mohammad
Liver transplantation (LT) is a serious hemostatic challenge in patients with portal vein thrombosis (PVT). Advances in monitoring systems have improved surgery in this setting. We report the successful application of a point-of-care (POC) rotational viscoelastic thromboelastometry-guided (TEM) testing system (ROTEM) which allowed management of coagulation during LT in a 64-year-old cirrhotic patient with a model for end-stage liver disease (MELD) score of 16. Perioperatively, the patient showed complete PVT, hepatomegaly, splenomegaly, recanalization of the umbilical vein, and portosystemic shunt. Macroscopic liver and spleen adherences with collateral circulation were evident. Coagulation factors and fibrinolysis were assessed preoperatively and at graft reperfusion to evaluate the need of hemostatic therapy. Based on ROTEM findings, the patient received 16?g of human fibrinogen concentrate, half preoperatively (with prothrombin complex concentrate 2000?IU, tranexamic acid 1?g, and platelets 2?IU), and two doses of 4?g before and after graft reperfusion; we achieved normalization of all monitored parameters. No ischemia-reperfusion syndrome was present. Postoperatively portal vein flux at Color-Doppler ultrasonography was normal. After a 3-day ICU stay, the patient was moved to the Department of Surgery and discharged on day 14. The postoperative course was uneventful and did not require any further haemostatic therapy.
Piangatelli, Cristiano; Faloia, Lucia; Valentini, Ilaria; Vivarelli, Marco
Liver transplantation (LT) is a serious hemostatic challenge in patients with portal vein thrombosis (PVT). Advances in monitoring systems have improved surgery in this setting. We report the successful application of a point-of-care (POC) rotational viscoelastic thromboelastometry-guided (TEM) testing system (ROTEM) which allowed management of coagulation during LT in a 64-year-old cirrhotic patient with a model for end-stage liver disease (MELD) score of 16. Perioperatively, the patient showed complete PVT, hepatomegaly, splenomegaly, recanalization of the umbilical vein, and portosystemic shunt. Macroscopic liver and spleen adherences with collateral circulation were evident. Coagulation factors and fibrinolysis were assessed preoperatively and at graft reperfusion to evaluate the need of hemostatic therapy. Based on ROTEM findings, the patient received 16?g of human fibrinogen concentrate, half preoperatively (with prothrombin complex concentrate 2000?IU, tranexamic acid 1?g, and platelets 2?IU), and two doses of 4?g before and after graft reperfusion; we achieved normalization of all monitored parameters. No ischemia-reperfusion syndrome was present. Postoperatively portal vein flux at Color-Doppler ultrasonography was normal. After a 3-day ICU stay, the patient was moved to the Department of Surgery and discharged on day 14. The postoperative course was uneventful and did not require any further haemostatic therapy. PMID:24653855
Piangatelli, Cristiano; Faloia, Lucia; Cristiani, Claudia; Valentini, Ilaria; Vivarelli, Marco
An automated point-of-care (POC) immunodetection system for immunological detection of staphylococcal enterotoxin B (SEB) was designed, fabricated, and tested. The system combines several elements: (i) enzyme-linked immunosorbent assay-lab-on-a-chip (ELISA-LOC) with fluidics, (ii) a charge-coupled device (CCD) camera detector, (iii) pumps and valves for fluid delivery to the ELISA-LOC, (iv) a computer interface board, and (v) a computer for controlling the fluidics, logging, and data analysis of the CCD data. The ELISA-LOC integrates a simple microfluidic system into a miniature 96-well sample plate, allowing the user to carry out immunological assays without a laboratory. The analyte is measured in a sandwich ELISA assay format combined with a sensitive electrochemiluminescence (ECL) detection method. Using the POC system, SEB, a major foodborne toxin, was detected at concentrations as low as 0.1 ng/ml. This is similar to the reported sensitivity of conventional ELISA. The open platform with simple modular fluid delivery automation design described here is interchangeable between detection systems, and because of its versatility it can also be used to automate many other LOC systems, simplifying LOC development. This new POC system is useful for carrying out various immunological and other complex medical assays without a laboratory and can easily be adapted for high-throughput biological screening in remote and resource-poor areas. PMID:21640067
Yang, Minghui; Sun, Steven; Kostov, Yordan; Rasooly, Avraham
Objectives The Massachusetts Veterans Epidemiology Research and Information Center in collaboration with the Stanford Center for Innovative Study Design set out to test the feasibility of a new method of evidence generation. The first pilot of a point-of-care clinical trial (POCCT), adding randomization and other study processes to an electronic medical record (EMR) system, was launched to compare the effectiveness of two insulin regimens. Materials and Methods Existing functionalities of the Veterans Affairs (VA) computerized patient record system (CPRS)/veterans health information systems and technology architecture (VISTA) were modified to support the activities of a randomized controlled trial including enrolment, randomization, and longitudinal data collection. Results The VA's CPRS/VISTA was successfully adapted to support the processes of a clinical trial and longitudinal study data are being collected from the medical record automatically. As of 30 June 2011, 55 of the 67 eligible patients approached received a randomized intervention. Discussion The design of CPRS/VISTA made integration of study workflows and data collection possible. Institutions and investigators considering similar designs must carefully map clinical workflows and clinical trial workflows to EMR capabilities. POCCT study teams are necessarily interdisciplinary and interdepartmental. As a result, executive sponsorship is critical. Conclusion POCCT represent a promising new method for conducting clinical science. Much work is needed to understand better the optimal uses and designs for this new approach. Next steps include focus groups to measure patient and clinician perceptions, multisite deployment of the current pilot, and implementation of additional studies.
Ferguson, Ryan; Goryachev, Sergey; Woods, Patricia; Sabin, Thomas; O'Neil, Joseph; Conrad, Chester; Gillon, Joseph; Escalera, Jasmine; Brophy, Mary; Lavori, Phillip; Fiore, Louis
Introduction: Early recognition of elevated lactate levels in sepsis may hasten the detection of those patients eligible for aggressive resuscitation. Point-of-care (POC) testing is now increasingly available for use in the emergency department (ED). We examined the accuracy and time-saving effect of a handheld POC device for the measurement of fingertip and whole blood lactate as compared with reference laboratory testing in critically ill ED patients. Methods: A convenience sample of adult ED patients receiving serum lactate testing was prospectively enrolled at an urban, tertiary care US hospital. Consenting patients underwent fingertip POC lactate measurement with a portable device and simultaneous whole blood sampling for analysis by both the POC device and standard laboratory analyzer (“reference method”). Lactate measurements were compared by intraclass correlation (ICC) and Bland and Altman plots. Differences in time to test result were compared by paired t test. Results: Twenty-four patients, 19 (79%) with sepsis and 21 (88%) with lactate levels below 4 mmol/L, were included from April 2005 to May 2005. Fingertip POC and whole blood POC lactate measurements each correlated tightly with the reference method (ICC = 0.90 and ICC = 0.92, respectively). Mean time between obtaining fingertip lactate samples and whole blood reference lactate samples was 8 ± 13 minutes. Mean time between obtaining POC and reference laboratory lactate results was 65 minutes (95% confidence interval, 30–103). Conclusion: Fingertip POC lactate measurement is an accurate method to determine lactate levels in infected ED patients with normal or modestly elevated lactate values and significantly decreases time to test results. These findings should be verified in a larger, more critically ill, ED population.
Gaieski, David F.; Drumheller, Byron C.; Goyal, Munish; Fuchs, Barry D.; Shofer, Frances S.; Zogby, Kara
We developed an automated point-of-care diagnostic instrument that is capable of analyzing nasal swab samples for the presence of respiratory diseases. This robust instrument, called FluIDx, performs autonomous multiplexed RT-PCR reactions that are analyzed by microsphere xMAP technology. We evaluated the performance of FluIDx, in comparison rapid tests specific for influenza and respiratory syncytial virus, in a clinical study performed at the UC Davis Medical Center. The clinical study included samples positive for RSV (n = 71), influenza A (n = 16), influenza B (n = 4), adenovirus (n = 5), parainfluenza virus (n = 2), and 44 negative samples, according to a composite reference method. FluIDx and the rapid tests detected 85.9% and 62.0% of the RSV positive samples, respectively. Similar sensitivities were recorded for the influenza B samples; whereas the influenza A samples were poorly detected, likely due to the utilization of an influenza A signature that did not accurately match currently circulating influenza A strains. Data for all pathogens were compiled and indicate that FluIDx is more sensitive than the rapid tests, detecting 74.2% (95% C.I. of 64.7-81.9%) of the positive samples in comparison to 53.6% (95% C.I. of 43.7-63.2%) for the rapid tests. The higher sensitivity of FluIDx was partially offset by a lower specificity, 77.3% versus 100.0%. Overall, these data suggest automated flow-through PCR-based instruments that perform multiplexed assays can successfully screen clinical samples for infectious diseases.
Regan, J F; Letant, S E; Adams, K L; Mahnke, R C; Nguyen, N T; Dzenitis, J M; Hindson, B J; Hadley, D R; Makarewicz, T J; Henderer, B D; Breneman, J W; Tammero, L F; Ortiz, J I; Derlet, R W; Cohen, S; Colston, W W; McBride, M T; Birch, J M
Often, high-sensitivity, point-of-care (POC) clinical tests, such as HIV viral load, require large volumes of plasma. Although centrifuges are ubiquitously used in clinical laboratories to separate plasma from whole blood, centrifugation is generally inappropriate for on-site testing. Suitable alternatives are not readily available to separate the relatively large volumes of plasma from milliliters of blood that may be needed to meet stringent limit-of-detection specifications for low-abundance target molecules. We report on a simple-to-use, low-cost, pump-free, membrane-based, sedimentation-assisted plasma separator capable of separating a relatively large volume of plasma from undiluted whole blood within minutes. This plasma separator consists of an asymmetric, porous, polysulfone membrane housed in a disposable chamber. The separation process takes advantage of both gravitational sedimentation of blood cells and size exclusion-based filtration. The plasma separator demonstrated a "blood in-plasma out" capability, consistently extracting 275 ± 33.5 ?L of plasma from 1.8 mL of undiluted whole blood within less than 7 min. The device was used to separate plasma laden with HIV viruses from HIV virus-spiked whole blood with recovery efficiencies of 95.5% ± 3.5%, 88.0% ± 9.5%, and 81.5% ± 12.1% for viral loads of 35,000, 3500, and 350 copies/mL, respectively. The separation process is self-terminating to prevent excessive hemolysis. The HIV-laden plasma was then injected into our custom-made microfluidic chip for nucleic acid testing and was successfully subjected to reverse-transcriptase loop-mediated isothermal amplification (RT-LAMP), demonstrating that the plasma is sufficiently pure to support high-efficiency nucleic acid amplification. PMID:24099566
Liu, Changchun; Mauk, Michael; Gross, Robert; Bushman, Frederic D; Edelstein, Paul H; Collman, Ronald G; Bau, Haim H
The adoption of PDAs and mobile communication is expected to provide a solution to the use of computer technology by healthcare workers at the point-of-care. The Australian National Health Information Strategy, Health Online, is providing national leadership for approaches to address the quality and availability of information to assist in the planning and delivery of care. One area for potential
Daniel Walsh; Carole Alcock; Lois Burgess; Joan Cooper
Computerized decision support for use at the point of care has to be comprehensive. It means that clinical information stored in electronic health records needs to be integrated with various forms of clinical knowledge ( elicited from experts, discovered from data or summarized in systematic reviews of clinical trials). In order to provide such comprehensive support we created the MET
Szymon Wilk; Wojtek Michalowski; Dympna O'Sullivan; Ken Farion; Stan Matwin
Counting the different subpopulations of cells in a fingerprick of human blood is important for a number of clinical Point of Care applications. It is a challenge to demonstrate the integration of sample preparation and detection techniques in a single platform. In this article we review the applications for PoC haematology and the current solutions that are available. We demonstrate
C. Van Berkel; J. D. Gwyer; S. Deane; V. Hollis; J. Holloway; N. Green; H. M. Morgan
About one third of all blood components transfused intraoperatively is used in cardiac surgery, whereas mortality of cardiosurgical patients correlates nearly linear with the number of transfused units of packed red blood cells. Acquired platelet function disorders play a major role in perioperative bleeding in cardiac surgery. Therefore, the use of point-of-care-suitable platelet function analyzers seems to be reasonable in
Klaus Görlinger; Csilla Jambor; Alexander A. Hanke; Daniel Dirkmann; Michael Adamzik; Matthias Hartmann; Niels Rahe-Meyer
The hybridizations between the HIV target DNA and the capture probes as well as the signal probes conjugated to the multi-invertase/nanoparticle composites lead to the conversion of sucrose to glucose, which is monitored by the personal glucometer and provides quantitative digital readings for point-of-care diagnosis of HIV DNA fragments. PMID:23011391
Xu, Jin; Jiang, Bingying; Xie, Jiaqing; Xiang, Yun; Yuan, Ruo; Chai, Yaqin
A joint project team consisting of personnel from Parkview Episcopal Medical Center, Pueblo, Colorado, and Patient Care Technologies, Atlanta, Georgia, a software vendor, codeveloped a point-of-care based system of electronic patient records and administrative data capture for home health care. Well established continuous quality improvement techniques, in use at Parkview for approximately 6 years, guided the development project and the subsequent alpha and beta testing of the system. Significant results to date include an overall productivity gain approaching 20%, the potential to increase annual home care revenue $876,000 with the same staffing level, and an 83% reduction in billing errors. Although not directly measured as a part of the study, the project team believes the quality of charting has improved because it is now done at the point-of-care in the home rather than in the office--some period of time after care is delivered. Anticipated future development includes integration of the home care clinical record with the hospital's clinical data repository and explicit support of critical pathways. PMID:7641132
Background. A nonrecognized pneumothorax (PTX) may become a life-threatening tension PTX. A reliable point-of-care diagnostic tool could help in reduce this risk. For this purpose, we investigated the feasibility of the use of the PneumoScan, an innovative device based on micropower impulse radar (MIR). Patients and Methods. addition to a standard diagnostic protocol including clinical examination, chest X-ray (CXR), and computed tomography (CT), 24 consecutive patients with chest trauma underwent PneumoScan testing in the shock trauma room to exclude a PTX. Results. The application of the PneumoScan was simple, quick, and reliable without functional disorder. Clinical examination and CXR each revealed one and PneumoScan three out of altogether four PTXs (sensitivity 75%, specificity 100%, positive predictive value 100%, and negative predictive value 95%). The undetected PTX did not require intervention. Conclusion. The PneumoScan as a point-of-care device offers additional diagnostic value in patient management following chest trauma. Further studies with more patients have to be performed to evaluate the diagnostic accuracy of the device.
Lindner, T.; Conze, M.; Albers, C. E.; Leidel, B. A.; Levy, P.; Kleber, C.; De Moya, M.; Exadaktylos, A.; Stoupis, C.
It is thought that new technologies like computers at the patient's bedside, or point of care technology (PCT) improve nursing productivity, documentation, patient satisfaction and decrease costs. Using the Health Care Technology Assessment (HCTA) framework, (safety, cost, effectiveness, social impact), a descriptive and quasi-experimental study was performed to test the effectiveness and explain the social impact of PCT. A sample of 90 patients from five nursing units in three hospitals were obtained for the study. Half of the patients had computers at their bedside. Data were collected on a hospital pretest/posttest unit and two comparison and experimental units. The main null hypothesis was: There is no difference in the quality of patient care on nursing units with and without PCT. Quality of patient care was measured by patient satisfaction and a nursing care documentation instruments. This hypothesis was rejected. While patients were generally very satisfied with their nursing care on all units, when controlling for time and the presence of the computer, patients who did not have PCT were more satisfied than patients in rooms with PCT. Furthermore, the charts of patients with PCT were less compliant to documentation standards. Conversely, a sub sample of these same patients expressed positive responses to the bedside computer and technologies in their room and this concurred with the current literature. The benefits of the technology were found to outweigh the costs of PCT from the literature review. There was not enough in the literature to draw conclusions about the safety of PCT. In summary, the quality of patient care did not improve with the implementation of PCT in this study.(ABSTRACT TRUNCATED AT 250 WORDS)
Happ, B. A.
Ultrasound offers sports medicine clinicians the potential to diagnose, treat, and manage a broad spectrum of conditions afflicting athletes. This review article highlights applications of ultrasound that hold promise as point-of-care diagnostics and therapeutic tools that can be used directly by clinicians to direct real-time management of athletes. Point-of-care ultrasound has been examined most in the context of musculoskeletal disorders in athletes, with attention given to Achilles tendinopathy, patellar tendinopathy, hip and thigh pathology, elbow tendinopathy, wrist pathology, and shoulder pain. More research has focused on therapeutic applications than diagnostic, but initial evidence has been generated in both. Preliminary evidence has been published also on abdominal ultrasound for splenic enlargement in mononucleosis, cardiopulmonary processes and hydration status, deep vein thrombosis, and bone mineral density. Further research will be required to validate these applications and to explore further applications of portable ultrasound that can be used in the care of athletes. PMID:23147017
Yim, Eugene S; Corrado, Gianmichel
The paper presents a virtual organization (VO) framework which incorporates wireless technology support at the point of care in a clinical environment It reflects a move to patient centric healthcare provided by multi-disciplinary care teams working in an integrated way for patient care. The work highlights the importance of wireless technologies for addressing point of care issues faced by care
Mohyuddin; W. A. Gray; Hazel Bailey; Carol Jordan; David Morrey
Introduction: Microalbuminuria is an accepted predictive marker for the early detection of renal disease and the identification of patients at high risk of developing complications of diabetes and hypertension. The Bayer Clinitek 50 is a urine chemistry point-of-care analyser for the semi-quantitative measurement of albumin and creatinine and calculation of albumin:creatinine ratio (ACR). Method: Urine samples were obtained from 252
Bernard L Croal; W. J Mutch; B. M Clark; A Dickie; J Church; D Noble; I. S Ross
From a user's point of view, a point-of-care system for home use should be wearable and easy to use in addition to satisfying requirements for medical devices. In this paper, we address mobility, power consumption, data storage, data transmission, and device synchronization for wearable home care devices that comply with the IEEE 1073 (medical information bus) standard. A wearable, standards-based,
Jianchu Yao; Ryan Schmitz; Steve Warren
This paper reports on the development of a lab-on-achip (LOC) sensor for rapid electrochemical point-of-care (POC) measurement of biological exposure to manganese (Mn). The sensor was fabricated using an electrodeposited bismuth film as a working electrode, and Ag\\/AgCl reference and Au auxiliary electrodes. Measurement of Mn was demonstrated in the 0.9 nM - 9 muM range in blood using square
Preetha Jothimuthu; Erin N. Haynes; Ian Papautsky
We present a low-cost microfluidic origami device for point-of-care extraction of bacterial DNA from raw viscous samples – a challenge for conventional microfluidic systems. The core idea is a novel method for sequencing arbitrarily complex chemical and physical processing steps through sequential folding of 2D surfaces. This folding creates temporary paper fluidic circuits substituting capillary flow for pumps, and folding
A. V. Govindarajan; S. Ramachandran; G. D. Vigil; P. Yager; K. F. Bohringer
This paper presents a novel disposable microfluidic vacuum module using inductively-trig gered transformative polymers for point-of-care diagnostics. Micropump and microvalve are the most popular devices as pressure sources for micro fluidic systems. However, micropumps\\/valve s make the micro fluidic systems complicated and sometimes unsuitable for disposable biochips due to complexity in structure\\/assemb ly. In this work, shape memory polymer materials
Chien-Chong Hong; Cheng-Han Tsai; Szu-Ying Chen; Chie-Pein Chen
Remote patient monitoring is an alternative to regular home check-ups of patients with certain special medical conditions or the elderly who are unable to regularly visit a healthcare facility. This technology reduces the number of home visits which are now only required when special attention is needed. This paper presents the design and development of a remote point-of-care patient monitoring
Ashwin K. Whitchurch; J. K. Abraham; V. K. Varadan
This paper describes the development of the sensor interface and driver program for a point of care (POC) device. The proposed POC device comprises an ARM9 embedded processor and eight- channel sensor input to measure various bio-signals. It features a user-friendly interface using a full- color TFT-LCD and touch-screen, and a bluetooth wireless communication module. The proposed device is based
Hong-Bum Son; Sung-Gun Song; Jae-Wook Jung; Chang-Su Lee; Seong-Mo Park
E-health delivers healthcare services and education, via a Web portal, to older persons with chronic conditions and their caregivers and enables the patient's home to be the point of care. This growing industry is ripe for exploration by nurses who can empower the patient and caregiver to gain self-care and coping skills. Advances in information technology now make this dream a reality. PMID:16006829
Moody, Linda E
A 35-day-old female infant presents to the pediatric emergency department with increased crying and persistent fullness in the right groin. On examination, the infant was noted to have increased fullness and a nonreducible mass in the right mons pubis. Point-of-care ultrasound was used to help diagnose an incarcerated ovary, allowing for expedited care while waiting for confirmatory imaging. The infant underwent surgery with salvage of the ovary. PMID:24786996
Tilt, Lindsey; Kessler, David O
Anciximab provides potent, but variable degrees of platelet inhibition both during the duration of intravenous administration and at 12 hours following therapy. Platelet function was assessed using the PC-RPFA system in 78 patients scheduled for percutaneous coronary revascularization who were administered the standard abciximab weight-adjusted bolus and 12-hour infusion. The PC-RPFA system is a cartridge-based, semiautomated point-of-care whole-blood assay that
Dean J. Kereiakes; Michele Mueller; Wendy Howard; Pam Lacock; Linda C. Anderson; Thomas M. Broderick; Eli M. Roth; Charles W. Abbottsmith
Objective: Two different point-of-care (POC) systems for the monitoring of coagulation variables at the bedside were evaluated with\\u000a regard to practicability, accuracy and costs. Design: Prospective, descriptive study. Setting: Single-institutional, clinical investigation on an intensive care unit (ICU) of an urban, university-affiliated hospital.\\u000a Patients: Eighty cardiac surgery patients were studied postoperatively. Interventions: Arterial blood samples were drawn postoperatively on the
J. Boldt; G. Walz; J. Triem; S. Suttner; B. Kumle
The use of point-of-care (POC) immunoassays has increased significantly and the menu of analytes continues to expand. Most of the rapid immunoassays are currently based on simple manual assay devices such as the immunochromatographic, agglutination, and immunofiltration assays. Although automated readers have recently been introduced at an increasing pace, the major benefit of these genuinely hand-portable assay devices is that
Piia von Lode
The biomedical field publishes a huge volume of articles every year and most of them are now available online as PDF full-texts.There is still no an effective search mechanisim that could locate the full-text articles very narrowly matching the users preference quickly. Such a mechanisim can be important for many real-time applications such as information at point of care for
Massuod Alatrash; Hao Ying; Peter Dews; Ming Dong; Wendy Wu; Michael Massanari
Veterinarians involved in Greyhound rescue have anecdotally observed that 10-15% of Greyhounds bleed profusely after simple surgical procedures. In most patients, platelet counts and hemostasis profiles are normal; therefore, it is possible that these dogs have platelet dysfunction. The PFA-100a is a novel point-of-care platelet function analyzer that has recently been evaluated as a rapid method to assess platelet function
C. G. Couto; A. Lara; M. C. Iazbik; M. B. Brooks
BackgroundThe need to rapidly evaluate patients presenting to emergency departments and cardiology services for ruling in and ruling out acute myocardial infarction (AMI) is widely recognized as a clinical challenge. We determined the impact of incorporating point-of-care (POC) cardiac troponin I (cTnI) testing into a cardiology service regarding assay turn around time (TAT), patient length of stay (LOS), financial matrixes
Fred S. Apple; Adrine Y. Chung; Mary Ellen Kogut; Susan Bubany; MaryAnn M. Murakami
In response to a broad-based need for point-of-care multiplex diagnostic capability, we have developed a novel hybrid platform to analyze optically encoded microspheres arranged on a 2-dimensional planar array. The microspheres which we have initially selected are developed by Luminex Inc. as substrates for sandwich-type fluorescent immunoassays and are typically used in conjunction with a customized flow analyzer. CCD-based optics are the essential feature which enables the development of a rugged diagnostic instrument which can be scaled for point-of-care applications. We have characterized the Multiplex Immunoassay Diagnostic System (MIDS) using a benchtop prototype built around a conventional 12-bit CCD. This system is capable of resolving up to 6 discrete classes of fluorescent microbeads, and measuring their corresponding reporter signal. The MIDS sensitivity to the phycoerythrin (PE) reporter compared favorably to that of the reference Luminex flow system, and is capable of identifying viral, bacterial, and protein simulants in laboratory samples, at concentrations less than 1µg/ml. The ability to resolve small differences in the average PE fluorescence is a direct function of CCD performance, and may be a necessary trade-off for developing a portable and economical detection system. However, we are confident that the MIDS platform can easily be scaled to meet the nominal requirements of any given point-of-care or screening application, and furthermore provide much-needed diagnostic functionality in this particular environment.
Chuang, Frank Y. S.; Gutierrez, Dora M.; Nguyen, Christine P.; Johnson, David C.; Palmer, Richard A.; Richards, James B.; Chang, John T.; Visuri, Steven R.; Colston, Bill W., Jr.
Cardiovascular disease remains the leading cause of death in the world and continues to serve as the major contributor to healthcare costs. Likewise, there is an ever-increasing need and demand for novel and more efficient diagnostic tools for the early detection of cardiovascular disease, especially at the point-of-care (POC). This article reviews the programmable bio-nanochip (P-BNC) system, a new medical microdevice approach with the capacity to deliver both high performance and reduced cost. This fully integrated, total analysis system leverages microelectronic components, microfabrication techniques, and nanotechnology to noninvasively measure multiple cardiac biomarkers in complex fluids, such as saliva, while offering diagnostic accuracy equal to laboratory-confined reference methods. This article profiles the P-BNC approach, describes its performance in real-world testing of clinical samples, and summarizes new opportunities for medical microdevices in the field of cardiac diagnostics. PMID:22891104
Christodoulides, Nicolaos; Pierre, Floriano N; Sanchez, Ximena; Li, Luanyi; Hocquard, Kyle; Patton, Aaron; Muldoon, Rachna; Miller, Craig S; Ebersole, Jeffrey L; Redding, Spencer; Yeh, Chih-Ko; Furmaga, Wieslaw B; Wampler, David A; Bozkurt, Biykem; Ballantyne, Christie M; McDevitt, John T
The agreement of plasma biochemical values between a portable point-of-care analyzer and a veterinary diagnostic laboratory in wild caught loggerhead sea turtles (Caretta caretta) was tested. Banked plasma samples from presumptively healthy turtles collected for an on-going project that involves health assessments of sea turtles from the southeast coast of Florida were used for this study. Plasma biochemical analytes evaluated included albumin, aspartate aminotransferase, calcium, creatinine kinase, glucose, potassium, sodium, phosphorus, total protein, bile acids, and uric acid. Paired plasma samples were run in duplicates and compared between a point-of-care analyzer and a veterinary diagnostic laboratory (VDL). Overall, the precision was greater as measured within the point-of-care analyzer than within the VDL analyzer; however, agreement between the two testing methods was poor. Correlation (r(i)) between the two analyzers was high for many of the analytes; however, the small P-value and high relative error led to the conclusion that the two analyzers were not equivalent. In addition, a comparison was made between the biochemical values obtained at the time of collection and after storage in an ultralow freezer for up to 2.5 yr. Plasma samples analyzed at the VDL, performed on different models of the same machine, were significantly lower after storage than those acquired near the time of collection. This difference was most likely because of sample degradation that occurred during storage. Whereas, statistically significant differences were observed within and between the analyzers, many of these differences may not be clinically significant. Even though this study has a few limitations, including a technical malfunction and the use of two different diagnostic laboratories, biochemical values for the given population are reported when using both a portable system and a diagnostic laboratory. Based on the findings of this study, the authors believe that point-of-care analyzers can provide valuable adjunctive diagnostics, especially in field situations. PMID:21370637
Atkins, Adrienne; Jacobson, Elliott; Hernandez, Jorge; Bolten, Alan B; Lu, Xiaomin
Needle trap devices (NTDs) have shown many advantages such as improved detection limits, reduced sampling time and volume, improved stability, and reproducibility if compared with other techniques used in breath analysis such as solid-phase extraction and solid-phase micro-extraction. Effects of sampling flow (2-30 ml/min) and volume (10-100 ml) were investigated in dry gas standards containing hydrocarbons, aldehydes, and aromatic compounds and in humid breath samples. NTDs contained (single-bed) polymer packing and (triple-bed) combinations of divinylbenzene/Carbopack X/Carboxen 1000. Substances were desorbed from the NTDs by means of thermal expansion and analyzed by gas chromatography-mass spectrometry. An automated CO2-controlled sampling device for direct alveolar sampling at the point-of-care was developed and tested in pilot experiments. Adsorption efficiency for small volatile organic compounds decreased and breakthrough increased when sampling was done with polymer needles from a water-saturated matrix (breath) instead from dry gas. Humidity did not affect analysis with triple-bed NTDs. These NTDs showed only small dependencies on sampling flow and low breakthrough from 1-5 %. The new sampling device was able to control crucial parameters such as sampling flow and volume. With triple-bed NTDs, substance amounts increased linearly with increasing sample volume when alveolar breath was pre-concentrated automatically. When compared with manual sampling, automatic sampling showed comparable or better results. Thorough control of sampling and adequate choice of adsorption material is mandatory for application of needle trap micro-extraction in vivo. The new CO2-controlled sampling device allows direct alveolar sampling at the point-of-care without the need of any additional sampling, storage, or pre-concentration steps. PMID:23388692
Trefz, Phillip; Rösner, Lisa; Hein, Dietmar; Schubert, Jochen K; Miekisch, Wolfram
AIM: To determine the diagnostic accuracy of a new point-of-care assay detecting anti-deamidated gliadin peptides in celiac disease (CD) patients. METHODS: One-hundred-and-twelve patients (age range: 1.8-79.2 years old) with clinical symptoms suggestive of CD and/or first-degree relatives (FDR) of CD patients (n = 66), and confirmed CD on a gluten-free diet (GFD) (n = 46), were prospectively enrolled in the study at Gastroenterology outpatient clinics for adult patients and from the Gastroenterology Consultation Ward at the Pediatric Department of the University Hospital of Geneva. Written informed consent was obtained from all subjects enrolled. The study received approval from the local ethics committee. The original CD diagnosis had been based on serum-positive IgA anti-tissue transglutaminase enzyme-linked immunosorbent assay (ELISA) (QuantaLite™, Inova Diagnostics, San Diego, CA, United States) and on biopsy results. Serum samples from all study participants were tested by the new CD lateral flow immunochromatographic assay (CD-LFIA) device, Simtomax® Blood Drop (Augurix SA, BioArk, Monthey, Switzerland) to detect immunoglobulin (Ig)A and IgG antibodies against deamidated gliadin peptides. The diagnostic performance was evaluated using receiver operating characteristic curves with 95%CIs. A cut-off of 2 on the Rann colorimetric scale was used to calculate the device’s sensitivity and specificity. RESULTS: CD-LFIA was highly accurate in detecting untreated celiac patients. In the group of patients with CD symptoms and/or FDR, eight new cases of CD were detected by ELISA and biopsy. All of these new cases were also correctly identified by CD-LFIA. The test yielded four false positive and four false negative results. The false positive results were all within the groups with clinical symptoms suggestive of CD and/or FDR, whereas the false negative results were all within the GFD group. The test yeld a sensitivity of 78.9% (95%CI: 54.4-93.9) and specificity of 95.7% (95%CI: 89.4-98.8), and the area under the curve reached 0.893 (95%CI: 0.798-0.988). The Kappa coefficient, calculated according to the values obtained by two readers from the same device, was of 0.96 (SE: 0.06). When the GFD patients were excluded from the analysis, the area under the curve reached 0.989 (95%CI: 0.971-1.000) and the Kappa coefficient, calculated according to the values obtained by two readers from the same device, became 0.96 (SE: 0.07). Furthermore, using the Rann scale cut-off of 2 without the GFD patients, sensitivity was 100% and specificity was 93.1% (95%CI: 83.3-98.1). CONCLUSION: The new CD-LFIA rapid screening test shows good diagnostic accuracy, sensitivity and specificity, and may rule out CD in patients with CD-related symptoms.
Benkebil, Faiza; Combescure, Christophe; Anghel, Silvia I; Besson Duvanel, Cecile; Schappi, Michela G
We present design criteria, operation principles and experimental examples of magnetic marker manipulation for our magnetic lab-on-a-chip prototype. It incorporates both magnetic sample preparation and detection by embedded GMR-type magnetoresistive sensors and is optimized for the automated point-of-care detection of four different sepsis-indicative cytokines directly from about 5 ?l of whole blood. The sample volume, magnetic particle size and cytokine concentration determine the microfluidic volume, sensor size and dimensioning of the magnetic gradient field generators. By optimizing these parameters to the specific diagnostic task, best performance is expected with respect to sensitivity, analysis time and reproducibility.
Schotter, Joerg; Shoshi, Astrit; Brueckl, Hubert
In the post-genomic era, ever-advancing capabilities in DNA detection and analysis have become vital to the detection of infectious diseases and the diagnosis of genetic abnormalities and inheritable diseases. The benefit of such capabilities, however, has yet to reach patients outside of centralized facilities. There thus exists an increasing need to decentralize DNA detection methods and to administer such diagnostics at the "point of care." Electrochemical-based DNA sensors present a compelling approach, but have yet to deliver satisfactory sensitivity, specificity, miniaturization, and real-time monitoring capability to meet the demand of point-of-care diagnostics. Motivated by their potential and their current limitations, in this dissertation, we present a series of strategies that we have undertaken in order to address the key shortcomings of electrochemical DNA sensors and advance them toward point-of-care applications. First, we report a single-step, single reagent, label-free, isothermal electrochemical DNA sensor based on the phenomenon of enzyme catalyzed target recycling amplification. Using this technique, we achieve improved detection limit in comparison to hybridization-based sensors without amplification. We also demonstrate greater than 16-fold amplification of signal at low target concentrations. Next, we present a novel electrochemical DNA sensor that detects single-nucleotide mismatched targets with unprecedented "polarity-switching" responses. This "bipolar" sensor employs a surface-bound and redox-modified (methylene blue) DNA probe architecture, and outputs a decreased Faradaic current when hybridized to a perfectly matched (PM) target, but conversely reports an increased Faradaic current when hybridized to a single-base mismatched (SM) target. Third, we describe the microfluidic electrochemical dynamic allele specific hybridization (microE-DASH) platform for versatile and rapid detection of single-nucleotide polymorphisms. Implementing electrochemical-based melting curve analysis within the microfluidic device, this platform directly detects PCR amplicon-like targets and distinguishes perfectly matched target from single-base mismatched target and heterozygote combination of both targets in 20 minutes. Finally, we present the microfluidic electrochemical quantitative loop-mediated isothermal amplification (MEQ-LAMP) platform for rapid, sensitive, and quantitative detection of pathogen genomic DNA at the point of care. DNA amplification is electrochemically monitored in real time within a monolithic microfluidic device, enabling the detection of as few as 16 copies of Salmonella genomic DNA via a single-step process in under an hour.
Lower abdominal pain in females of reproductive age continues to be a diagnostic dilemma for the emergency physician (EP). Point-of-care ultrasound (US) allows for rapid, accurate, and safe evaluation of abdominal and pelvic pain in both the pregnant and non-pregnant patient. We present 3 cases of females presenting with right lower quadrant and adnexal tenderness where transvaginal ultrasonography revealed acute appendicitis. The discussion focuses on the use of EP- performed transvaginal US in gynecologic and intra-abdominal pathology and discusses the use of a staged approach to evaluation using US and computed tomography, as indicated.
Bramante, Robert; Radomski, Marek; Nelson, Mathew; Raio, Christopher
Lower abdominal pain in females of reproductive age continues to be a diagnostic dilemma for the emergency physician (EP). Point-of-care ultrasound (US) allows for rapid, accurate, and safe evaluation of abdominal and pelvic pain in both the pregnant and non-pregnant patient. We present 3 cases of females presenting with right lower quadrant and adnexal tenderness where transvaginal ultrasonography revealed acute appendicitis. The discussion focuses on the use of EP- performed transvaginal US in gynecologic and intra-abdominal pathology and discusses the use of a staged approach to evaluation using US and computed tomography, as indicated. PMID:24106529
Bramante, Robert; Radomski, Marek; Nelson, Mathew; Raio, Christopher
Global burdens from existing or emerging infectious diseases emphasize the need for point-of-care (POC) diagnostics to enhance timely recognition and intervention. Molecular approaches based on PCR methods have made significant inroads by improving detection time and accuracy but are still largely hampered by resource-intensive processing in centralized laboratories, thereby precluding their routine bedside- or field-use. Microfluidic technologies have enabled miniaturization of PCR processes onto a chip device with potential benefits including speed, cost, portability, throughput, and automation. In this review, we provide an overview of recent advances in microfluidic PCR technologies and discuss practical issues and perspectives related to implementing them into infectious disease diagnostics.
Park, Seungkyung; Zhang, Yi; Lin, Shin; Wang, Tza-Huei; Yang, Samuel
Randomized controlled trials have traditionally been the gold standard against which all other sources of clinical evidence are measured. However, the cost of conducting these trials can be prohibitive. In addition, evidence from the trials frequently rests on narrow patient-inclusion criteria and thus may not generalize well to real clinical situations. Given the increasing availability of comprehensive clinical data in electronic health records (EHRs), some health system leaders are now advocating for a shift away from traditional trials and toward large-scale retrospective studies, which can use practice-based evidence that is generated as a by-product of clinical processes. Other thought leaders in clinical research suggest that EHRs should be used to lower the cost of trials by integrating point-of-care randomization and data capture into clinical processes. We believe that a successful learning health care system will require both approaches, and we suggest a model that resolves this escalating tension: a "green button" function within EHRs to help clinicians leverage aggregate patient data for decision making at the point of care. Giving clinicians such a tool would support patient care decisions in the absence of gold-standard evidence and would help prioritize clinical questions for which EHR-enabled randomization should be carried out. The privacy rule in the Health Insurance Portability and Accountability Act (HIPAA) of 1996 may require revision to support this novel use of patient data. PMID:25006150
Longhurst, Christopher A; Harrington, Robert A; Shah, Nigam H
Microfluidics have become an enabling technology for point-of-care and personalized diagnostics. Desirable capabilities of microfluidics-based diagnostic devices include simplicity, portability, low cost and the performance of multiplexed and quantitative measurements, ideally in a high-throughput format. Here we present the multiplexed volumetric bar-chart chip (V-Chip), which integrates all these capabilities in one device. A key feature of the V-Chip is that quantitative results are displayed as bar charts directly on the device-without the need for optical instruments or any data processing or plotting steps. This is achieved by directly linking oxygen production by catalase, which is proportional to the concentration of the analyte, with the displacement of ink along channels on the device. We demonstrate the rapid quantification of protein biomarkers in diverse clinical samples with the V-Chip. The development of the V-Chip thus opens up the possibility of greatly simplified point-of-care and personalized diagnostics. PMID:23250413
Song, Yujun; Zhang, Yuanqing; Bernard, Paul E; Reuben, James M; Ueno, Naoto T; Arlinghaus, Ralph B; Zu, Youli; Qin, Lidong
Since its initial introduction into the bedside assessment of the trauma patient via the Focused Assessment with Sonography for Trauma (FAST) exam, the use of point-of-care ultrasound has expanded rapidly. A growing body of literature demonstrates ultrasound can be used by nonradiologists as an extension of the physical exam to accurately diagnose or exclude a variety of conditions. These conditions include, but are not limited to, hemoperitoneum, pneumothorax, pulmonary edema, long-bone fracture, deep vein thrombosis, and elevated intracranial pressure. As ultrasound machines have become more compact and portable, their use has extended outside of hospitals to places where the physical exam and diagnostic capabilities may be limited, including the aviation environment. A number of studies using focused sonography have been performed to meet the diagnostic challenges of space medicine. The following article reviews the available literature on portable ultrasound use in aerospace medicine and highlights both known and potential applications of point-of-care ultrasound for the aeromedical clinician. PMID:25022161
Wagner, Michael S; Garcia, Kathleen; Martin, David S
Point-of-care evidence-based medicine websites allow physicians to answer clinical queries using recent evidence at the bedside. Despite significant research into the function, usability and effectiveness of these programmes, little attention has been paid to their ethical issues. As many of these sites summarise the literature and provide recommendations, we sought to assess the role of conflicts of interest in two widely used websites: UpToDate and Dynamed. We recorded all conflicts of interest for six articles detailing treatment for the following conditions: erectile dysfunction, fibromyalgia, hypogonadism, psoriasis, rheumatoid arthritis and Crohn's disease. These diseases were chosen as their medical management is either controversial, or they are treated using biological drugs which are mostly available by brand name only. Thus, we hypothesised that the role of conflict of interest would be more significant in these conditions than in an illness treated with generic medications or by strict guidelines. All articles from the UpToDate articles demonstrated a conflict of interest. At times, the editor and author would have a financial relationship with a company whose drug was mentioned within the article. This is in contrast with articles on the Dynamed website, in which no author or editor had a documented conflict. We offer recommendations regarding the role of conflict of interest disclosure in these point-of-care evidence-based medicine websites. PMID:24493079
Amber, Kyle T; Dhiman, Gaurav; Goodman, Kenneth W
Immediate response for disease control relies on simple, inexpensive, and sensitive diagnostic tests, highly sought after for timely and accurate test of various diseases, including infectious diseases. Composite Fe3O4/Au nanoparticles have attracted considerable interest in diagnostic applications due to their unique physical and chemical properties. Here, we developed a simple coating procedure for gold magnetic nanoparticles (GMNs) with poly(acrylic acid) (PAA). PAA-coated GMNs (PGMNs) were stable and monodispersed and characterized by Fourier transform-infrared spectroscopy (FT-IR), transmission electron microscopy, UV-visible scanning spectrophotometry, thermogravimetric analysis, and Zetasizer methodologies. For diagnostic application, we established a novel lateral flow immunoassay (LFIA) strip test system where recombinant Treponema pallidum antigens (r-Tp) were conjugated with PGMNs to construct a particle probe for detection of anti-Tp antibodies. Intriguingly, the particle probes specifically identified Tp antibodies with a detection limitation as low as 1 national clinical unit/mL (NCU/mL). An ample pool of 1020 sera samples from three independent hospitals were obtained to assess our PGMNs-based LFIA strips, which exhibited substantially high values of sensitivity and specificity for all clinical tests (higher than 97%) and, therefore, proved to be a suitable approach for syphilis screening at a point-of-care test manner. PMID:23735054
Yang, Dong; Ma, Jianzhong; Zhang, Qinlu; Li, Ningning; Yang, Jiangcun; Raju, Paul Ananda; Peng, Mingli; Luo, Yanling; Hui, Wenli; Chen, Chao; Cui, Yali
The emerging field of point-of-care clinical diagnostics based on lab-on-a-chip microsystems is underway. CMOS technology, which is responsible for present revolution in computing and communications by pushing ever-smaller semiconductor devices, has recently been used for the implementation of low-power and small-size microsystems for point-of-care diagnostics. The design considerations, recent advances and future directions of these CMOS-based microsystems are discussed in
Background Non-adherence to prescribed medications is a serious health problem in the United States, costing an estimated $100 billion per year. While poor adherence should be addressable with point of care health information technology, integrating new solutions with existing electronic health records (EHR) systems require customization within each organization, which is difficult because of the monolithic software design of most EHR products. Objective The objective of this study was to create a published algorithm for predicting medication adherence problems easily accessible at the point of care through a Web application that runs on the Substitutable Medical Apps, Reusuable Technologies (SMART) platform. The SMART platform is an emerging framework that enables EHR systems to behave as “iPhone like platforms” by exhibiting an application programming interface for easy addition and deletion of third party apps. The app is presented as a point of care solution to monitoring medication adherence as well as a sufficiently general, modular application that may serve as an example and template for other SMART apps. Methods The widely used, open source Django framework was used together with the SMART platform to create the interoperable components of this app. Django uses Python as its core programming language. This allows statistical and mathematical modules to be created from a large array of Python numerical libraries and assembled together with the core app to create flexible and sophisticated EHR functionality. Algorithms that predict individual adherence are derived from a retrospective study of dispensed medication claims from a large private insurance plan. Patients’ prescription fill information is accessed through the SMART framework and the embedded algorithms compute adherence information, including predicted adherence one year after the first prescription fill. Open source graphing software is used to display patient medication information and the results of statistical prediction of future adherence on a clinician-facing Web interface. Results The user interface allows the physician to quickly review all medications in a patient record for potential non-adherence problems. A gap-check and current medication possession ratio (MPR) threshold test are applied to all medications in the record to test for current non-adherence. Predictions of 1-year non-adherence are made for certain drug classes for which external data was available. Information is presented graphically to indicate present non-adherence, or predicted non-adherence at one year, based on early prescription fulfillment patterns. The MPR Monitor app is installed in the SMART reference container as the “MPR Monitor”, where it is publically available for use and testing. MPR is an acronym for Medication Possession Ratio, a commonly used measure of adherence to a prescribed medication regime. This app may be used as an example for creating additional functionality by replacing statistical and display algorithms with new code in a cycle of rapid prototyping and implementation or as a framework for a new SMART app. Conclusions The MPR Monitor app is a useful pilot project for monitoring medication adherence. It also provides an example that integrates several open source software components, including the Python-based Django Web framework and python-based graphics, to build a SMART app that allows complex decision support methods to be encapsulated to enhance EHR functionality.
Mandel, Joshua; Jonikas, Magdalena; Ramoni, Rachel Badovinac; Kohane, Isaac S; Mandl, Kenneth D
In this article, the process used to develop and validate an integrated quality-control system for a cartridge-based, point-of-care system for critical care analysis is outlined. Application of risk management principles has resulted in a quality control system using a combination of statistical quality control with onboard reference solutions and failure pattern recognition used to flag common failure modes during the analytical phase of the testing process. A combination of traditional external quality control, integrated quality control to monitor ongoing instrument functionality, operator training, and other laboratory-implemented monitors is most effective in controlling known failure modes during the testing process. PMID:23331731
D'Orazio, Paul; Mansouri, Sohrab
For many drugs, finding the balance between efficacy and toxicity requires monitoring their concentrations in the patient's blood. Quantifying drug levels at the bedside or at home would have advantages in terms of therapeutic outcome and convenience, but current techniques require the setting of a diagnostic laboratory. We have developed semisynthetic bioluminescent sensors that permit precise measurements of drug concentrations in patient samples by spotting minimal volumes on paper and recording the signal using a simple point-and-shoot camera. Our sensors have a modular design consisting of a protein-based and a synthetic part and can be engineered to selectively recognize a wide range of drugs, including immunosuppressants, antiepileptics, anticancer agents and antiarrhythmics. This low-cost point-of-care method could make therapies safer, increase the convenience of doctors and patients and make therapeutic drug monitoring available in regions with poor infrastructure. PMID:24907901
Griss, Rudolf; Schena, Alberto; Reymond, Luc; Patiny, Luc; Werner, Dominique; Tinberg, Christine E; Baker, David; Johnsson, Kai
The utility of personal digital assistants (PDA) as a point of care resource in health care practice and education presents new challenges for nursing faculty. While there is a plethora of PDA resources available, little is known about the variables that effect student learning and technology adoption. In this study nursing students used PDA software programs which included a drug guide, medical dictionary, laboratory manual and nursing diagnosis manual during acute care clinical experiences. Analysis of student journals comparative reflective statements about the PDA as an adjunct to other available resources in clinical practice are presented. The benefits of having a PDA included readily available data, validation of thinking processes, and facilitation of care plan re-evaluation. Students reported increased frequency of use and independence. Significant correlations between user perceptions and computer self-efficacy suggested greater confidence in abilities with technology resulting in increased self-awareness and achievement of learning outcomes. PMID:20196764
This paper presents a review, based on the published literature and on the authors’ own research, of the current state of the art of fiber-optic capillary sensors and related instrumentation as well as their applications, with special emphasis on point-of-care chemical and biochemical sensors, systematizing the various types of sensors from the point of view of the principles of their construction and operation. Unlike classical fiber-optic sensors which rely on changes in light propagation inside the fiber as affected by outside conditions, optical capillary sensors rely on changes of light transmission in capillaries filled with the analyzed liquid, which opens the possibility of interesting new applications, while raising specific issues relating to the construction, materials and instrumentation of those sensors.
Borecki, Michal; Korwin-Pawlowski, Michael L.; Beblowska, Maria; Szmidt, Jan; Jakubowski, Andrzej
Silicon photonic biosensors based on evanescent wave detection have revealed themselves as the most promising candidates for achieving truly point-of-care devices as they can overcome the limitations of current analytical techniques. Advantages such as miniaturization, extreme sensitivity, robustness, reliability, potential for multiplexing and mass production at low cost can be offered. Among the existing integrated optical sensors, the interferometric ones are the most attractive due to their extreme sensitivity for label-free and real-time evaluations with detection limits close to 10-7- 10-8 in bulk refractive index. In this article we will review the recent progress in the most common interferometric waveguide biosensors (Mach-Zehnder interferometers, Young interferometers, Hartman interferometers, dual polarization interferometers and bimodal optical waveguides). In particular, we will focus on the description of their optical structures and their applicability for bioanalytical detection.
Duval, D.; González-Guerrero, A. B.; Dante, S.; Domínguez, C.; Lechuga, L. M.
Little is known about disparities in preventive asthma care delivery at the time of an office visit. Our objective was to better understand what treatments are delivered at the point of care for urban children with asthma, and whether there are racial disparities. We enrolled 100 Black and 77 White children (2-12 years) with persistent asthma from 6 primary care practices. We evaluated how frequently providers delivered guideline-based asthma actions at the index visit. We also assessed asthma morbidity prior to the index visit and again at 2 month follow-up. Black children had greater symptom severity and were less likely to report having a preventive medication at baseline, but were no more likely to report a preventive medication action at the time of an office visit. Symptoms persisted for Black children at follow-up, suggesting additional preventive actions were needed. Further efforts to promote consistent guideline-based preventive asthma care are critical. PMID:24435717
Lewis, Porschea; Fagnano, Maria; Koehler, Alana; Halterman, Jill S
MicroRNAs or miRNAs are a form of small non-coding RNAs (ncRNAs) of 19–22 nucleotides in length in their mature form. miRNAs are transcribed in the nucleus of all cells from large precursors, many of which have several kilobases in length. Originally identified as intracellular modulators of protein synthesis via posttranscriptional gene silencing, more recently it has been found that miRNAs can travel in extracellular human fluids inside specialized vesicles known as exosomes. We will be referring to this miRNAs as circulating microRNAs. More interestingly, the miRNA content inside exosomes changes during pathological events. In the present review we analyze the literature about circulating miRNAs and their possible use as biomarkers. Furthermore, we explore their future in point-of-care (POC) diagnostics and provide an example of a portable POC apparatus useful in the detection of circulating miRNAs.
Here, we present an integrated Lab-on-a-Chip (LOC) system based on silicon microring resonator devices. The system comprises of an electrical tracing-assisted silicon dual-microring sensor which requires a low-cost broadband light source instead of a bulky and expensive tunable laser therefore allows the development of cost-effective point-of-care (POC) diagnostic device. Highly efficient and fast nucleic acids detection with silicon microring device is demonstrated using an isothermal solid-phase amplification/detection (ISAD) technique. The integrated LOC system consists of dualmicroring sensors and microfluidic device for sample processing together with ISAD technique offers true realization of POC device for human disease diagnosis.
Park, Mi Kyoung; Liu, Qing; Kim, Kyung Woo; Shin, Yong; Kee, Jack Sheng; Song, Junfeng; Lo, Guo-Qiang; Kwong, Dim-Lee
Computerized decision support for use at the point of care has to be comprehensive. It means that clinical information stored in electronic health records needs to be integrated with various forms of clinical knowledge (elicited from experts, discovered from data or summarized in systematic reviews of clinical trials). In order to provide such comprehensive support we created the MET-A3Support framework for constructing clinical applications aimed at various medical conditions. We employed the multiagent system paradigm and the O-MaSE methodology to define an engineering process involving three main activities: requirements engineering, analysis and design. Then we applied the process to build MET-A3Support. The paper describes the engineering process and its results, including models representing selected elements of our framework.
Wilk, Szymon; Michalowski, Wojtek; O'Sullivan, Dympna; Farion, Ken; Matwin, Stan
This paper presents a review, based on the published literature and on the authors' own research, of the current state of the art of fiber-optic capillary sensors and related instrumentation as well as their applications, with special emphasis on point-of-care chemical and biochemical sensors, systematizing the various types of sensors from the point of view of the principles of their construction and operation. Unlike classical fiber-optic sensors which rely on changes in light propagation inside the fiber as affected by outside conditions, optical capillary sensors rely on changes of light transmission in capillaries filled with the analyzed liquid, which opens the possibility of interesting new applications, while raising specific issues relating to the construction, materials and instrumentation of those sensors. PMID:22319325
Borecki, Micha?; Korwin-Pawlowski, Michael L; Beblowska, Maria; Szmidt, Jan; Jakubowski, Andrzej
An ultrafast microfluidic PCR module (30 PCR cycles in 6 min) based on the oscillating fluid plug concept was developed. A robust amplification of native genomic DNA from whole blood samples could be achieved at operational conditions established from systematic investigations of key parameters including heat transfer and in particular flow velocities. Experimental data were augmented with results from computational fluid dynamics simulations. The reproducibility of the current system was substantially improved compared to previous concepts by integration of a closed reservoir instead of utilizing a vented channel end at ambient pressure rendering the devised module suitable for integration into complex sample-to-answer analysis platforms such as point-of-care applications. PMID:23065712
Brunklaus, Sabine; Hansen-Hagge, Thomas E; Erwes, Julia; Höth, Julian; Jung, Mathieu; Latta, Daniel; Strobach, Xenia; Winkler, Christian; Ritzi-Lehnert, Marion; Drese, Klaus S
Incorporation of point-of-care ultrasound into the skill set of Special Operations medical providers should come with an appreciation of the potential limitations of the technology. We present a case of a U.S. Army Special Forces Soldier who suffered traumatic monocular vision loss after being struck in the eye during a combatives tournament. Evaluation in the emergency department (ED) included an unremarkable ocular ultrasound, despite a high clinical suspicion of intraocular pathology. Ophthalmologic consultation was obtained emergently. Optical coherence topography and a dilated fundoscopic examination were performed, which revealed a small subretinal hemorrhage. We will review the history of ocular ultrasound and its sensitivity to detect intraocular pathology. We will also emphasize the need to obtain specialty consultation when the clinical suspicion for intraocular pathology is high despite a negative ocular ultrasound. PMID:23526323
Nydam, Timothy; Tanksley, Steve
This paper presents a novel approach of using a miniaturized potentiostat (M-P) chip (LMP91000) to perform full range cyclic voltammetry (CV) measurements for the detection of biomarkers. The LMP91000 evaluation board was reconfigured to perform three-electrode CV measurements in order to achieve electrochemical cortisol immunosensing. The microelectrodes for cortisol estimation were fabricated by immobilizing monoclonal anti-cortisol antibody (Anti-M-Cab) onto self-assembled monolayer (SAM) modified Au microelectrodes. The results obtained using the M-P were compared to those obtained using a conventional potentiostat. The M-P was successful in measuring cortisol levels in the range of pM. The outcomes of the studies suggest that M-P can effectively perform biochemical measurements on three electrode systems, enabling the development of miniature systems for point-of-care (POC) diagnosis. PMID:25016332
Cruz, Andres Felipe Diaz; Norena, Nicolas; Kaushik, Ajeet; Bhansali, Shekhar
Background Allergy is a serious problem affecting approximately 1 of 4 individuals. The symptoms with and without allergy etiology are often difficult to distinguish from each other without using an IgE antibody test. The aim of this study was to investigate the performance of a new point-of-care (POC) test for IgE antibodies to relevant allergens in Europe. Methods IgE antibodies from children and adults with allergies recruited from allergy clinics in Sweden and Spain were analyzed for 10 allergens, suitable for the age groups, using the new POC test and ImmunoCAP laboratory test. The IgE antibody level best discriminating between positive and negative results (the cutoff point) for the different allergens of the POC test and the efficacy of the POC and the ImmunoCAP laboratory tests for diagnosing allergy compared with that of clinical diagnosis were investigated. Results The estimated cutoffs for the different allergens in the POC test ranged from 0.70 to 2.56 kUA/L. Taking into account all positive allergen results in a given patient, the POC test could identify 95% of the patients with allergies. Seventy-eight percent of the allergen-specific physicians' diagnoses were identified and 97% of the negative ones. Most allergens exhibited good performance, identifying about 80% of clinically relevant cases. However, dog, mugwort, and wall pellitory would benefit from improvement. Conclusions The POC test will be a valuable adjunct in the identification or exclusion of patients with allergies and their most likely offending allergens, both in specialist and general care settings.
Everyday lifestyle related issues are the main cause of psychological stress, which contributes to health disparities experienced by individuals. Prolonged exposure to stress leads to the activation of signaling pathways from the brain that leads to release of cortisol from the adrenal cortex. Various biomarkers have been affected by psychological stress, but cortisol "a steroid hormone" is known as a potential biomarker for its estimation. Cortisol can also be used as a target analyte marker to determine the effect of exposure such as organophosphates on central nervous system, which alters the endocrine system, leading to imbalance in cortisol secretion. Cortisol secretion of individuals depends on day-night cycle and field environment hence its detection at point-of-care (POC) is deemed essential to provide personalized healthcare. Chromatographic techniques have been traditionally used to detect cortisol. The issues relating to assay formation, system complexity, and multistep extraction/purification limits its application in the field. In order to overcome these issues and to make portable and effective miniaturized platform, various immunoassays sensing strategies are being explored. However, electrochemical immunosensing of cortisol is considered as a recent advancement towards POC application. Highly sensitive, label-free and selective cortisol immunosensor based on microelectrodes are being integrated with the microfluidic system for automated diurnal cortisol monitoring useful for personalized healthcare. Although the reported sensing devices for cortisol detection may have a great scope to improve portability, electronic designing, performance of the integrated sensor, data safety and lifetime for point-of-care applications, This review is an attempt to describe the various cortisol sensing platforms and their potential to be integrated into a wearable system for online and continuous monitoring of cortisol rhythm at POC as a function of one's environment. PMID:24212052
Kaushik, Ajeet; Vasudev, Abhay; Arya, Sunil K; Pasha, Syed Khalid; Bhansali, Shekhar
A major challenge for the lab-on-a-chip (LOC) community is to develop point-of-care diagnostic chips that do not use instruments.\\u000a Such instruments include pumping or liquid handling devices for distribution of patient’s nucleic-acid test sample among an\\u000a array of reactors and microvalves or mechanical parts to seal these reactors. In this paper, we report the development of\\u000a a primer pair pre-loaded
Naveen Ramalingam; Hao-Bing Liu; Chang-Chun Dai; Yu Jiang; Hui Wang; Qinghui Wang; Kam M Hui; Hai-Qing Gong
A simple, point of care, inexpensive, disposable cassette for the detection of nucleic acids extracted from pathogens was designed, constructed, and tested. The cassette utilizes a single reaction chamber for isothermal amplification of nucleic acids. The chamber is equipped with an integrated, flow-through, Flinders Technology Associates (Whatman FTA®) membrane for the isolation, concentration, and purification of DNA and/or RNA. The nucleic acids captured by the membrane are used directly as templates for amplification without elution, thus simplifying the cassette's flow control. The FTA membrane also serves another critical role-enabling the removal of inhibitors that dramatically reduce detection sensitivity. Thermal control is provided with a thin film heater external to the cassette. The amplification process was monitored in real time with a portable, compact fluorescent reader. The utility of the integrated, single-chamber cassette was demonstrated by detecting the presence of HIV-1 in oral fluids. The HIV RNA was reverse transcribed and subjected to loop-mediated, isothermal amplification (LAMP). A detection limit of less than 10 HIV particles was demonstrated. The cassette is particularly suitable for resource poor regions, where funds and trained personnel are in short supply. The cassette can be readily modified to detect nucleic acids associated with other pathogens borne in saliva, urine, and other body fluids as well as in water and food. PMID:21455542
Liu, Changchun; Geva, Eran; Mauk, Michael; Qiu, Xianbo; Abrams, William R; Malamud, Daniel; Curtis, Kelly; Owen, S Michele; Bau, Haim H
Background Dyspnea is one of the most frequent complaints in the Emergency Department. Thoracic ultrasound should help to differentiate cardiogenic from non-cardiogenic causes of dyspnea. We evaluated whether the diagnostic accuracy can be improved by adding a point-of-care-ultrasonography (POC-US) to routine exams and if an early use of this technique produces any advantage. Methods One hundred sixty-eight patients were enrolled and randomized in two groups: Group 1 received an immediate POC-US in addition to routine laboratory and instrumental tests; group 2 received an ultrasound scan within 1 h from the admission to the Emergency Department. The concordance between initial and final diagnosis and the percentage of wrong diagnosis in the two groups were evaluated. Mortality, days of hospitalization in Emergency Medicine department and transfers to other wards were compared. Sensitivity and specificity of the routine protocol and the one including ultrasonography for the diagnosis of the causes of dyspnea were also analyzed. Results Eighty-eight patients were randomized in group 1 and 80 in group 2. The concordance rate between initial and final diagnoses was significantly different (0.94 in group 1 vs. 0.22 in group 2, p?0.005). The percentage of wrong initial diagnosis was 5% in group 1 and 50% in group 2 (p?0.0001). Conclusions Adding POC-US to routine exams improves the diagnostic accuracy of dyspnea and reduces errors in the Emergency Department.
An optical biosensor system using surface-plasmon field-enhanced fluorescence has been developed, which allows high sensitivity and fast measurement available. Intensity of fluorophores in SPFS is highly dependent upon the distance from metal surface. The resonant evanescent electric field excites fluorophores within the penetration area. On the other hand, fluorescence quenching in close proximity to a metal surface interfere with the excitation. We have developed a new technology for fluorescent nanoparticles that could receive the energy from metal surface effectively. This enables technology of detecting strong and stable SPFS signals, as well as homogeneous assay method that allows us to eliminate binding/free separation process for unreacted fluorescent particles. A rate assay method has also been employed, which resolves affect from diffusion-limited access, in order to realize a fast surface immunoreaction in a microchannel. Taking advantage of these two developments, as eliminating an enzyme response process such as CLEIA, our system reaches much faster reaction time of 2 minutes to detect thyroid stimulating hormone (TSH) of canine serum sample at 0.1ng/mL. We believe our system with these new technologies is a powerful tool for in-vitro diagnosis which meets various clinical requirements.
Horii, Kazuyoshi; Kimura, Toshihito; Ohtsuka, Hisashi; Kasagi, Noriyuki; Oohara, Tomoya; Matsuno, Tadahiro; Hakamata, Masashi; Komatsu, Akihiro; Sendai, Tomonari
It represents a viable solution for the realization of a portable biosensor platform that could screen/diagnose acute myocardial infarction by measuring cardiac marker concentrations such as cardiac troponin I (cTnI), creatine kinase MB (CK-MB), and myoglobin (MYO) for application to u-health monitoring system. The portable biosensor platform introduced in this presentation has a more compact structure and a much higher measuring resolution than a conventional spectrometer system. Portable guided-mode resonance (GMR) biosensor platform was composed of a biosensor chip stage, an optical pick-up module, and a data display panel. Disposable plastic GMR biosensor chips with nano-grating patterns were fabricated by injection-molding. Whole blood filtration and label-free immunoassay were performed on these single chips, automatically. Optical pick-up module was fabricated by using the miniaturized bulk optics and the interconnecting optical fibers and a tunable VCSEL (vertical cavity surface emitting laser). The reflectance spectrum from the GMR biosensor was measured by the optical pick-up module. Cardiac markers in human serum with concentrations less than 0.1ng/mL were analyzed using a GMR biosensor. Analysis time was 30min, which is short enough to meet clinical requirements. Our results show that the GMR biosensor will be very useful in developing lowcost portable biosensors that can screen for cardiac diseases.
Sung, Gun Yong; Kim, Wan-Joong; Ko, Hyunsung; Kim, Bong K.; Kim, Kyung-Hyun; Huh, Chul; Hong, Jongcheol
A non-invasive test for oro-ileal transit time (OITT) evaluation was developed, based on the measurement of tauroursodeoxycholic acid (TUDCA) oral fluid concentration profile after its oral administration. Exploiting the fact that TUDCA is actively absorbed only in the ileum, OITT is measured as the time corresponding to TUDCA maximum oral fluid concentration (tmax). To measure oral fluid TUDCA concentration in a point-of-care setting, an ultrasensitive portable immunosensor was developed, based on a competitive chemiluminescent enzyme immunoassay (CL-EIA), using immobilized anti-TUDCA antibody and an ursodeoxycholic acid (UDCA)-peroxidase conjugate as tracer, detected by enhanced chemiluminescence employing a portable charge-coupled device (CCD)-based device. The test was validated in 24 healthy subjects before and after treatment with Loperamide, a drug that increases OITT. The developed CL-EIA was accurate and precise, with a LLOQ of 50 pmol L(-1). The measured OITT for healthy subjects (291 ± 50 min) was fairly well correlated with OITT values obtained by measuring TUDCA in serum (r=0.89). An increased OITT was observed in all the studied subjects after Loperamide treatment. The CL immunosensor can be employed directly in gastroenterology and paediatric units and it can thus represent a new non-invasive simple test for OITT evaluation in a point-of-care setting, with improved diagnostic utility. PMID:23587552
Simoni, Patrizia; Magliulo, Maria; Mirasoli, Mara; Vestito, Amanda; Festi, Davide; Roda, Giulia; Colecchia, Antonio; Roda, Aldo
Telavancin is approved in the United States, Canada, and Europe (At the time of submission, the telavancin European marketing authorization for nosocomial pneumonia was suspended until Theravance provides evidence of a new European Medicines Agency approved supplier) as an antibiotic to treat certain Gram-positive bacterial skin infections. Telavancin has been shown to prolong plasmatic prothrombin (PT) and activated partial thromboplastin (aPTT) clotting times in clinical diagnostic lab-based assays. In this study, we evaluated the potential for telavancin to prolong whole blood PT/International Normalized Ratio (INR) and aPTT tests on point-of-care (POC) instruments. Whole blood collected from 8 healthy subjects was supplemented with telavancin to final concentrations of 0, 10, 20, and 100 ?g/ml. Final concentrations were selected to match trough, twice trough, and peak plasma levels following the approved 10 mg/kg dose. Four widely employed POC coagulation instruments were chosen to be representative of the POC platforms currently in use.. These systems were the Roche Coaguchek XS, the Abbott iSTAT, the ITC Hemochron SIG+, and the Alere INRatio2 POC devices. The PT/INR measured by the Coaguchek XS showed the greatest sensitivity to the presence of telavancin. The PT/INR measured by the Hemochron SIG+ and iSTAT were sensitive to telavancin but to a lesser extent. The INRatio2 was the least sensitive to the presence of telavancin when testing the whole blood PT/INR. Only the Hemochron SIG+ device was capable of measuring aPTT and showed a concentration-dependent increase in aPTT. This study supports the current recommendation that PT and aPTT monitoring be conducted immediately to the next dose of telavancin when coagulation parameters are tested using POC instrumentation. PMID:24132401
Ero, Michael P; Harvey, Nathaniel R; Harbert, Jack L; Janc, James W; Chin, Kay H; Barriere, Steven L
CD4+ T cell enumeration is used to determine eligibility for antiretroviral therapy (ART) and to monitor the immune status of HIV-positive patients; however, many patients do not have access to this essential diagnostic test. Introducing point of care (POC) testing may improve access. We have evaluated Alere’s PIMA™, one such POC device, against conventional CD4+ testing platforms to determine its performance and validity for use in Kenya. In our hands, Alere PIMA™ had a coefficient of variability of 10.3% and of repeatability of 175.6 cells/µl. It differed from both the BD FACSCalibur™ (r2?=?0.762, mean bias ?64.8 cells/µl), and the BD FACSCount™ (r2?=?0.874, mean bias 7.8 cells/µl). When compared to the FACSCalibur™ at a cutoff of 350 cells/µl, it had a sensitivity of 89.6% and a specificity of 86.7% in those aged 5 years and over (Kw?=?0.7566). With the BD FACSCount™, it had a sensitivity of 79.4% and a specificity of 83.4% in those aged 5 years and over (Kw?=?0.7790). The device also differed from PARTEC Cyflow™ (r2?=?0.781, mean bias ?24.2 cells/µl) and GUAVA™ (r2?=?0.658, mean bias ?0.3 cells/µl) platforms, which are used in some facilities in Kenya. We conclude that with refinement, Alere PIMA™ technology has potential benefits for HIV-positive patients. This study highlights the difficulty in selecting the most appropriate reference technology for technical evaluations.
Mwau, Matilu; Adungo, Ferdinard; Kadima, Silvia; Njagi, Ephantus; Kirwaye, Carolyne; Abubakr, Najma Salim; Okubi, Lucy Atsieno; Waihenya, Mary; Lusike, Judi; Hungu, Jackson
Reported methods for the detection of the yellow fever viral genome are beset by limitations in sensitivity, specificity, strain detection spectra, and suitability to laboratories with simple infrastructure in areas of endemicity. We describe the development of two different approaches affording sensitive and specific detection of the yellow fever genome: a real-time reverse transcription-quantitative PCR (RT-qPCR) and an isothermal protocol employing the same primer-probe set but based on helicase-dependent amplification technology (RT-tHDA). Both assays were evaluated using yellow fever cell culture supernatants as well as spiked and clinical samples. We demonstrate reliable detection by both assays of different strains of yellow fever virus with improved sensitivity and specificity. The RT-qPCR assay is a powerful tool for reference or diagnostic laboratories with real-time PCR capability, while the isothermal RT-tHDA assay represents a useful alternative to earlier amplification techniques for the molecular diagnosis of yellow fever by field or point-of-care laboratories.
Patel, Pranav; Yillah, Jasmin; Weidmann, Manfred; Mendez, Jairo A.; Nakoune, Emmanuel Rivalyn; Niedrig, Matthias
Objective: This paper examines the use of Semantic MEDLINE, a natural language processing application enhanced with a statistical algorithm known as Combo, as a potential decision support tool for clinicians. Semantic MEDLINE summarizes text in PubMed citations, transforming it into compact declarations that are filtered according to a user's information need that can be displayed in a graphic interface. Integration of the Combo algorithm enables Semantic MEDLINE to deliver information salient to many diverse needs. Methods: The authors selected three disease topics and crafted PubMed search queries to retrieve citations addressing the prevention of these diseases. They then processed the citations with Semantic MEDLINE, with the Combo algorithm enhancement. To evaluate the results, they constructed a reference standard for each disease topic consisting of preventive interventions recommended by a commercial decision support tool. Results: Semantic MEDLINE with Combo produced an average recall of 79% in primary and secondary analyses, an average precision of 45%, and a final average F-score of 0.57. Conclusion: This new approach to point-of-care information delivery holds promise as a decision support tool for clinicians. Health sciences libraries could implement such technologies to deliver tailored information to their users.
Workman, T. Elizabeth; Stoddart, Joan M
Nucleic acid aptamers have many of the properties that make for effective reagents in point-of-care diagnostic devices and whilst superficially similar to antibodies as affinity reagents the scope for engineering them to fit this role is considerable. Synthesis of aptamers allows for the incorporation of functionality for both immobilisation and electrochemical signalling in a way that is compatible with the 'strip' type sensors familiar in enzyme sensors, such as those for glucose. Control of the structure of DNA aptamers through Watson-Crick base pairing allows for different electrochemical assay formats, whilst ferrocenes provide a versatile redox label and insights into the interactions between the aptamer and its target are obtained through both cyclic and square-wave voltammetries. Square-wave voltammetry in particular demonstrates good analytical utility. Two different approaches were used to assemble aptamer/redox probe structures on the surface of gold electrodes and both showed "signal on" behaviour (i.e. the current increases in the presence of analyte) although the two different methods appear to give quite distinct surface coatings. PMID:21413174
Cass, Anthony E G; Zhang, Yangyang
MicroRNAs or miRNAs are a form of small non-coding RNAs (ncRNAs) of 19-22 nucleotides in length in their mature form. miRNAs are transcribed in the nucleus of all cells from large precursors, many of which have several kilobases in length. Originally identified as intracellular modulators of protein synthesis via posttranscriptional gene silencing, more recently it has been found that miRNAs can travel in extracellular human fluids inside specialized vesicles known as exosomes. We will be referring to this miRNAs as circulating microRNAs. More interestingly, the miRNA content inside exosomes changes during pathological events. In the present review we analyze the literature about circulating miRNAs and their possible use as biomarkers. Furthermore, we explore their future in point-of-care (POC) diagnostics and provide an example of a portable POC apparatus useful in the detection of circulating miRNAs. PMID:24858962
Objective: The research sought to establish a rubric for evaluating evidence-based medicine (EBM) point-of-care tools in a health sciences library. Methods: The authors searched the literature for EBM tool evaluations and found that most previous reviews were designed to evaluate the ability of an EBM tool to answer a clinical question. The researchers' goal was to develop and complete rubrics for assessing these tools based on criteria for a general evaluation of tools (reviewing content, search options, quality control, and grading) and criteria for an evaluation of clinical summaries (searching tools for treatments of common diagnoses and evaluating summaries for quality control). Results: Differences between EBM tools' options, content coverage, and usability were minimal. However, the products' methods for locating and grading evidence varied widely in transparency and process. Conclusions: As EBM tools are constantly updating and evolving, evaluation of these tools needs to be conducted frequently. Standards for evaluating EBM tools need to be established, with one method being the use of objective rubrics. In addition, EBM tools need to provide more information about authorship, reviewers, methods for evidence collection, and grading system employed.
Foster, Margaret J
Rapid and precise patterning of functional biomaterials is desirable for point-of-care (POC) tissue engineering and diagnostics. However, existing technologies such as dip-pen nanolithography and inkjet printing are currently unsuitable for POC applications due to issues of cost and portability. Here, we report the development of 'BioPen', a portable tool for continuous, defined and scalable deposition of functional materials with micrometer spatial resolution and nanolitre volumetric resolution. BioPen is based upon the ballpoint pen but with multiple "ink sources" (functional material solutions) and with an apparatus that can be optimized for writing living cells, proteins, nucleic acids, etc. We demonstrate POC detection of human immunodeficiency virus type 1 (HIV-1) nucleic acid by writing on paper with BioPen using "ink" consisting of nucleic acid probes and nucleic acid-modified gold nanoparticles. We also demonstrate POC tissue engineering by writing a continuous pattern of living, functional, interconnected cells with a defined extracellular environment. Because it is simple, accurate, inexpensive and portable, BioPen has broad potential for POC detection of diagnostic biomarkers, and for POC engineering of tissues for a range of healing applications. PMID:24799039
Han, Yu Long; Hu, Jie; Genin, Guy M; Lu, Tian Jian; Xu, Feng
There is a growing demand to integrate biosensors with microfluidics to provide miniaturized platforms with many favorable properties, such as reduced sample volume, decreased processing time, low cost analysis and low reagent consumption. These microfluidics-integrated biosensors would also have numerous advantages such as laminar flow, minimal handling of hazardous materials, multiple sample detection in parallel, portability and versatility in design. Microfluidics involves the science and technology of manipulation of fluids at the micro- to nano-liter level. It is predicted that combining biosensors with microfluidic chips will yield enhanced analytical capability, and widen the possibilities for applications in clinical diagnostics. The recent developments in microfluidics have helped researchers working in industries and educational institutes to adopt some of these platforms for point-of-care (POC) diagnostics. This review focuses on the latest advancements in the fields of microfluidic biosensing technologies, and on the challenges and possible solutions for translation of this technology for POC diagnostic applications. We also discuss the fabrication techniques required for developing microfluidic-integrated biosensors, recently reported biomarkers, and the prospects of POC diagnostics in the medical industry. PMID:24019250
Kumar, Suveen; Kumar, Saurabh; Ali, Md Azahar; Anand, Pinki; Agrawal, Ved Varun; John, Renu; Maji, Sagar; Malhotra, Bansi D
In the 90s, efforts arise in the scientific world to automate and integrate one or several laboratory applications in tinny devices by using microfluidic principles and fabrication technologies used mainly in the microelectronics field. It showed to be a valid method to obtain better reactions efficiency, shorter analysis times, and lower reagents consumption over existing analytical techniques. Traditionally, these fluidic microsystems able to realize laboratory essays are known as Lab-On-a-Chip (LOC) devices. The capability to transport cells, bacteria or biomolecules in an aqueous medium has significant potential for these microdevices, also known as micro-Total-Analysis Systems (uTAS) when their application is of analytical nature. In particular, the technique of dielectrophoresis (DEP) opened the possibility to manipulate, actuate or transport such biological particles being of great potential in medical diagnostics, environmental control or food processing. This technique consists on applying amplitude and frequency controlled AC signal to a given microsystem in order to manipulate or sort cells. Furthermore, the combination of this technique with electrical impedance measurements, at a single or multiple frequencies, is of great importance to achieve novel reliable diagnostic devices. This is because the sorting and manipulating mechanism can be easily combined with a fully characterizing method able to discriminate cells. The paper is focused in the electronics design of the quadrature DEP generator and the four-electrode impedance measurement modules. These together with the lab-on-a-chip device define a full conception of an envisaged Point-of-Care (POC) device.
Del Moral Zamora, B.; Colomer-Farrarons, J.; Mir-Llorente, M.; Homs-Corbera, A.; Miribel-Català, P.; Samitier-Martí, J.
We present a cost-effective portable ultrasound system based on a single field-programmable gate array (FPGA) for point-of-care applications. In the portable ultrasound system developed, all the ultrasound signal and image processing modules, including an effective 32-channel receive beamformer with pseudo-dynamic focusing, are embedded in an FPGA chip. For overall system control, a mobile processor running Linux at 667 MHz is used. The scan-converted ultrasound image data from the FPGA are directly transferred to the system controller via external direct memory access without a video processing unit. The potable ultrasound system developed can provide real-time B-mode imaging with a maximum frame rate of 30, and it has a battery life of approximately 1.5 h. These results indicate that the single FPGA-based portable ultrasound system developed is able to meet the processing requirements in medical ultrasound imaging while providing improved flexibility for adapting to emerging POC applications. PMID:22828834
Kim, Gi-Duck; Yoon, Changhan; Kye, Sang-Bum; Lee, Youngbae; Kang, Jeeun; Yoo, Yangmo; Song, Tai-kyong
With the growing number of aging population and a significant portion of that suffering from cardiac diseases, it is conceivable that remote ECG patient monitoring systems are expected to be widely used as Point-of-Care (PoC) applications in hospitals around the world. Therefore, huge amount of ECG signal collected by Body Sensor Networks (BSNs) from remote patients at homes will be transmitted along with other physiological readings such as blood pressure, temperature, glucose level etc. and diagnosed by those remote patient monitoring systems. It is utterly important that patient confidentiality is protected while data is being transmitted over the public network as well as when they are stored in hospital servers used by remote monitoring systems. In this paper, a wavelet based steganography technique has been introduced which combines encryption and scrambling technique to protect patient confidential data. The proposed method allows ECG signal to hide its corresponding patient confidential data and other physiological information thus guaranteeing the integration between ECG and the rest. To evaluate the effectiveness of the proposed technique on the ECG signal, two distortion measurement metrics have been used: the Percentage Residual Difference (PRD) and the Wavelet Weighted PRD (WWPRD). It is found that the proposed technique provides high security protection for patients data with low (less than 1% ) distortion and ECG data remains diagnosable after watermarking (i.e. hiding patient confidential data) and as well as after watermarks (i.e. hidden data) are removed from the watermarked data. PMID:23708767
Ibaida, Ayman; Khalil, Ibrahim
A novel, compact-sized (19 cm × 16 cm) and portable (500 g) magnetic resonance relaxometry system is designed and developed. We overcame several key engineering barriers so that magnetic resonance technology can be potentially used for disease diagnosis-monitoring in point-of-care settings, directly on biological cells and tissues. The whole system consists of a coin-sized permanent magnet (0.76 T), miniaturized radio-frequency microcoil probe, compact lumped-circuit duplexer, and single board 1-W power amplifier, in which a field programmable gate array -based spectrometer is used for pulse excitation, signal acquisition, and data processing. We show that by measuring the proton transverse relaxation rates from a large pool of natural abundance proton-nuclei presence in less than 1 ?L of red blood cells, one can indirectly deduce the relative magnetic susceptibility of the bulk cells within a few minutes of signal acquisition time. Such rapid and sensitive blood screening system can be used to monitor the fluctuation of the bulk magnetic susceptibility of the biological cells (e.g., human blood cells), where unusual state of the bulk magnetic susceptibility is related to a number of diseases.
Peng, Weng Kung; Chen, Lan; Han, Jongyoon
Rapid and precise patterning of functional biomaterials is desirable for point-of-care (POC) tissue engineering and diagnostics. However, existing technologies such as dip-pen nanolithography and inkjet printing are currently unsuitable for POC applications due to issues of cost and portability. Here, we report the development of `BioPen', a portable tool for continuous, defined and scalable deposition of functional materials with micrometer spatial resolution and nanolitre volumetric resolution. BioPen is based upon the ballpoint pen but with multiple ``ink sources'' (functional material solutions) and with an apparatus that can be optimized for writing living cells, proteins, nucleic acids, etc. We demonstrate POC detection of human immunodeficiency virus type 1 (HIV-1) nucleic acid by writing on paper with BioPen using ``ink'' consisting of nucleic acid probes and nucleic acid-modified gold nanoparticles. We also demonstrate POC tissue engineering by writing a continuous pattern of living, functional, interconnected cells with a defined extracellular environment. Because it is simple, accurate, inexpensive and portable, BioPen has broad potential for POC detection of diagnostic biomarkers, and for POC engineering of tissues for a range of healing applications.
Han, Yu Long; Hu, Jie; Genin, Guy M.; Lu, Tian Jian; Xu, Feng
Rapid and precise patterning of functional biomaterials is desirable for point-of-care (POC) tissue engineering and diagnostics. However, existing technologies such as dip-pen nanolithography and inkjet printing are currently unsuitable for POC applications due to issues of cost and portability. Here, we report the development of ‘BioPen', a portable tool for continuous, defined and scalable deposition of functional materials with micrometer spatial resolution and nanolitre volumetric resolution. BioPen is based upon the ballpoint pen but with multiple “ink sources” (functional material solutions) and with an apparatus that can be optimized for writing living cells, proteins, nucleic acids, etc. We demonstrate POC detection of human immunodeficiency virus type 1 (HIV-1) nucleic acid by writing on paper with BioPen using “ink” consisting of nucleic acid probes and nucleic acid-modified gold nanoparticles. We also demonstrate POC tissue engineering by writing a continuous pattern of living, functional, interconnected cells with a defined extracellular environment. Because it is simple, accurate, inexpensive and portable, BioPen has broad potential for POC detection of diagnostic biomarkers, and for POC engineering of tissues for a range of healing applications.
Han, Yu Long; Hu, Jie; Genin, Guy M.; Lu, Tian Jian; Xu, Feng
This study used both survey and interview questionnaires. It was designed to assess the feasibility, usability, and utility of two point-of-care tools especially prepared with information relevant for dementia care by staff nurses in a small, a medium-sized, and a large nursing home in Florida. Twenty-five LPN or RN nurses were recruited for the…
Qadri, Syeda S.; Wang, Jia; Ruiz, Jorge G.; Roos, Bernard A.
A simple, sensitive optical analyzer for the rapid determination of cyanide in blood in point of care applications is described. HCN is liberated by the addition of 20% H3PO4 and is absorbed by a paper filter impregnated with borate-buffered (pH 9.0) hydroxoaquocobinamide Hereinafter called cobinamide). Cobinamide on the filter changes color from orange (?max = 510 nm) to violet (?max = 583 nm) upon reaction with cyanide. This color change is monitored in the transmission mode by a light emitting diode (LED) with a 583 nm emission maximum and a photodiode detector. The observed rate of color change increases 10x when the cobinamide solution for filter impregnation is prepared in borate-buffer rather than in water. The use of a second LED emitting at 653 nm and alternate pulsing of the LEDs improve the limit of detection by 4x to ~ 0.5 ?M for a 1 mL blood sample. Blood cyanide levels of imminent concern (? 10 ?M) can be accurately measured in ~ 2 min. The response is proportional to the mass of cyanide in the sample – smaller sample volumes can be successfully used with proportionate change in the concentration LODs. Bubbling air through the blood-acid mixture was found effective for mixing of the acid with the sample and the liberation of HCN. A small amount of ethanol added to the top of the blood was found to be the most effective means to prevent frothing during aeration. The relative standard deviation (RSD) for repetitive determination of blood samples containing 9 ?M CN was 1.09% (n=5). The technique was compared blind with a standard microdiffusion-spectrophotometric method used for the determination of cyanide in rabbit blood. The results showed good correlation (slope 1.05, r2 0.9257); independent calibration standards were used.
Ma, Jian; Ohira, Shin-Ichi; Mishra, Santosh K.; Puanngam, Mahitti; Dasgupta, Purnendu K.; Mahon, Sari B.; Brenner, Matthew; Blackledge, William; Boss, Gerry R.
Early detection of Mycobacterium tuberculosis complex (MTBC) and markers conveying drug resistance can have a beneficial impact on preventive public health actions. We describe here a new molecular point-of-care (POC) system, the Genedrive, which is based on simple sample preparation combined with PCR to detect MTBC and simultaneously detect mutation markers in the rpoB gene directly from raw sputum sample. Hybridization probes were used to detect the presence of the key mutations in codons 516, 526, and 531 of the rpoB gene. The sensitivities for MTBC and rpoB detection from sputum samples were assessed using model samples spiked with known numbers of bacteria prepared from liquid cultures of M. tuberculosis. The overall sensitivities were 90.8% (95% confidence interval [CI], 81, 96.5) for MTBC detection and 72.3% (95% CI, 59.8, 82.7) for rpoB detection. For samples containing ?1,000 CFU/ml, the sensitivities were 100% for MTBC and 85.7% for rpoB detection, while for samples containing ?100 CFU/ml, the sensitivities were 86.4% and 65.9% for MTBC and rpoB detection, respectively. The specificity was shown to be 100% (95% CI, 83.2, 100) for MTBC and rpoB. The clinical sputum samples were processed using the same protocol and showed good concordance with the data generated from the model. Tuberculosis-infected subjects with smear samples assessed as scanty or negative were detectable by the Genedrive system. In these paucibacillary patients, the performance of the Genedrive system was comparable to that of the GeneXpert assay. The characteristics of the Genedrive platform make it particularly useful for detecting MTBC and rifampin resistance in low-resource settings and for reducing the burden of tuberculosis disease. PMID:24478480
Castan, Pablo; de Pablo, Alicia; Fernández-Romero, Natalia; Rubio, José Miguel; Cobb, Benjamin D; Mingorance, Jesús; Toro, Carlos
Universal screening for gestational diabetes mellitus (GDM) is advocated in Indian women as they have the highest frequency of GDM, among South Asian population. For this the diagnostic procedure has to be simple, economical and evidence based. Hence, this study was undertaken to compare the point-of-care measuring capillary blood glucose (CBG) by glucometer and venous plasma glucose (VPG) estimated in the laboratory and to suggest the feasible diagnostic tool. Consecutive pregnant women in the third trimester were included in this study with the approval of the institutional ethical committee. They were given 75 g oral glucose in the fasting state. After 2 hours, CBG was measured by finger-prick using one touch select simple glucometer and venous blood was drawn to estimate VPG in the laboratory by GOD- POD method. The diagnosis of GDM was based on 2 hours plasma glucose > or = 7.8 mmol/l. Among a cohort of 500 pregnant women, 32 (6.4%) were diagnosed as GDM in their first visit. The CBG value at 2 hours plasma glucose > or = 7.8 mmol/l had a sensitivity of 93.8% and specificity of 97.4% with a false positive and false negative of 2.6% and 6.2%, respectively. The area under the receiver operating characteristic curve of CBG was 0.993. CBG value at 2 hours plasma glucose > or = 7.8 mmol/l may be recommended for the diagnosis of GDM in healthcare centres where laboratory technology is not available. PMID:23360023
Balaji, Vijayam; Balaji, Madhuri S; Paneerselvam, Arunachalam; Thiyagarajah, Arthi; Seshiah, Veerasamy
The current serological diagnostic method can be time consuming and labor intensive, which is not practical for on-site diagnosis and screening of infectious diseases. Capacitive bioaffinity detection using microelectrodes is considered as a promising label-free method for point-of-care diagnosis, though with challenges in sensitivity and the time "from sample to result." With recent development in AC electrokinetics (ACEK), especially in dielectrophoresis (DEP), we are able to develop an ACEK enhanced capacitive bioaffinity sensing method to realize simple, fast and sensitive diagnosis from serum samples. The capacitive immunosensor presented here employs elevated AC potentials at a fixed frequency for impedimetric interrogation of the microelectrodes. According to prior work, such an AC signal is capable of inducing dielectrophoresis and other ACEK effects, so as to realize in-situ enrichment of macromolecules at microelectrodes and hence accelerated detection. Experimental study of the ACEK-enhanced capacitive sensing method was conducted, and the results corroborate our hypothesis. The capacitive sensing responses showed clear frequency dependence and voltage-level dependency, which supports the hypothesis that ACEK aids the antigen-antibody binding, and these dependencies were used to optimize our detection protocol. Our capacitive sensing method was shown to work with bovine sera to differentiate disease-positive samples from negative samples within 2 min, while conventional immunoassay would require multiple processing steps and take hours to complete. The results showed high accuracy and sensitivity. The detection limit is found to reach 10 ng/ml in 2 min. The ACEK-enhanced capacitive immunosensor is a platform technology, and can be employed to detect any combination of probe (e.g. antigen) and analyte (e.g. serum antibody) in a small volume of bodily fluids. PMID:24007749
Li, Shanshan; Cui, Haochen; Yuan, Quan; Wu, Jie; Wadhwa, Ashutosh; Eda, Shigetoshi; Jiang, Hongyuan
Traditional flow cytometry designs tend to be bulky systems with a complex optical-fluidic sub-system and often require trained personnel for operation. This makes them difficult to readily translate to remote site testing applications. A new compact and portable fiber-optic flow cell (FOFC) technology has been developed at INO. We designed and engineered a specialty optical fiber through which a square hole is transversally bored by laser micromachining. A capillary is fitted into that hole to flow analyte within the fiber square cross-section for detection and counting. With demonstrated performance benchmarks potentially comparable to commercial flow cytometers, our FOFC provides several advantages compared to classic free-space con-figurations, e.g., sheathless flow, low cost, reduced number of optical components, no need for alignment (occurring in the fabrication process only), ease-of-use, miniaturization, portability, and robustness. This sheathless configuration, based on a fiber optic flow module, renders this cytometer amenable to space-grade microgravity environments. We present our recent results for an all-fiber approach to achieve a miniature FOFC to translate flow cytometry from bench to a portable, point-of-care device for deployment in remote settings. Our unique fiber approach provides the capability to illuminate a large surface with a uniform intensity distri-bution, independently of the initial shape originating from the light source, and without loss of optical power. The CVs and sensitivities are measured and compared to industry benchmarks. Finally, integration of LEDs enable several advantages in cost, compactness, and wavelength availability.
Background Neonatal infections annually claim lives of 1.4 million neonates worldwide. Until now, there is no ideal diagnostic test for detecting sepsis and thus management of possible sepsis cases often depends on clinical algorithm leading to empirical treatment. This often results in unnecessary antibiotic use, which may lead to emergence of antibiotic resistance. Biomarkers have shown great promise in diagnosis of sepsis and guiding appropriate treatment of neonates. In this study, we conducted a literature review of existing biomarkers to analyze their status for use as a point-of-care diagnostic in developing countries. Methods PubMed and EMBASE database were searched with keywords, ‘infections’, ‘neonates’, and ‘biomarkers’ to retrieve potentially relevant papers from the period 1980 to 2010. Leading hospitals and manufacturers were communicated to inquire about the cost, laboratory requirements and current standing of biomarkers in clinical use. Results The search returned 6407 papers on biomarkers; 65 were selected after applying inclusion and exclusion criteria. Among the studies, C-reactive protein (CRP), procalcitonin (PCT) and interleukin 6 (IL-6) were the most widely studied biomarkers and were considered to be most promising for diagnosing neonatal infections. About 90% of the studies were from developed countries; more than 50% were from Europe. Conclusions Extensive work is being performed to find the diagnostic and prognostic value of biomarkers. However, the methodologies and study design are highly variable. Despite numerous research papers on biomarkers, their use in clinical setting is limited to CRP. The methods for detection of biomarkers are far too advanced to be used at the community level where most of the babies are dying. It is important that a harmonized multi-site study is initiated to find a battery of biomarkers for diagnosis of neonatal infections.
Meem, Mahbuba; Modak, Joyanta K.; Mortuza, Roman; Morshed, Mahboob; Islam, Mohammad Shahidul; Saha, Samir K.
Background The World Health Organization now recommends the provision of praziquantel treatment to preschool-aged children infected with schistosomiasis. For intestinal schistosomiasis the current operational field diagnostic standard is examination of a thick Kato-Katz smear by microscopy prepared from a single stool specimen, and although pragmatic, this methodology has well-known shortcomings. Here, as a potential alternative, the performance of the urine circulating cathodic antigen (CCA) dipstick test was assessed in terms of disease-mapping and point-of-care diagnosis for intestinal schistosomiasis in preschool-aged children. Our manuscript reports on findings at baseline and at the end of a one-year longitudinal treatment study. Methodology/Principal Findings A total of 925 children (mean age 2.8 years) were initially recruited from six lakeshore villages representative of high, moderate and low levels of disease transmission. At baseline, all children were tested for intestinal schistosomiasis by microscopic examination of duplicate Kato-Katz smears prepared from a single stool faecal, by antigen detection with the urine CCA dipstick test and by serology with a commercially available ELISA test (as ‘gold-standard’) that measures host antibody titres to soluble egg antigens. As a point-of-care diagnosis, the urine CCA dipstick test achieved sensitivity and specificity values ranging from 52.5–63.2% and 57.7–75.6%, respectively, with faecal microscopy achieving very high specificities (>87%) but sensitivities as low as 16.7% in the low transmission setting. Conclusion/Significance The urine CCA test was shown to be more effective than faecal microscopy especially in lower transmission settings. The diagnostic performance of this test was not significantly impacted by treatment history or co-infections with other intestinal helminths.
Sousa-Figueiredo, Jose Carlos; Betson, Martha; Kabatereine, Narcis B.; Stothard, J. Russell
Functionalized magnetic nanoparticles are important components in biorecognition and medical diagnostics. Here, we present a review of our contribution to this interdisciplinary research field. We start by describing a simple one-step process for the synthesis of highly uniform ferrite nanoparticles (d = 20-200 nm) and their functionalization with amino acids via carboxyl groups. For real-world applications, we used admicellar polymerization to produce 200 nm diameter 'FG beads', consisting of several 40 nm diameter ferrite nanoparticles encapsulated in a co-polymer of styrene and glycidyl methacrylate for high throughput molecular screening. The highly dispersive FG beads were functionalized with an ethylene glycol diglycidyl ether spacer and used for affinity purification of methotrexate-an anti-cancer agent. We synthesized sub-100 nm diameter magnetic nanocapsules by exploiting the self-assembly of viral capsid protein pentamers, where single 8, 20, and 27 nm nanoparticles were encapsulated with VP1 pentamers for applications including MRI contrast agents. The FG beads are now commercially available for use in fully automated bio-screening systems. We also incorporated europium complexes inside a polymer matrix to produce 140 nm diameter fluorescent-ferrite beads (FF beads), which emit at 618 nm. These FF beads were used for immunofluorescent staining for diagnosis of cancer metastases to lymph nodes during cancer resection surgery by labeling tumor cell epidermal growth factor receptor (EGFRs), and for the detection of brain natriuretic peptide (BNP)-a hormone secreted in excess amounts by the heart when stressed-to a level of 2.0 pg ml(-1). We also describe our work on Hall biosensors made using InSb and GaAs/InGaAs/AlGaAs 2DEG heterostructures integrated with gold current strips to reduce measurement times. Our approach for the detection of sub-200 nm magnetic bead is also described: we exploit the magnetically induced capture of micrometer sized 'probe beads' by nanometer sized 'target beads', enabling the detection of small concentrations of beads as small as 8 nm in 'pumpless' microcapillary systems. Finally, we describe a 'label-less homogeneous' procedure referred to as 'magneto-optical transmission (MT) sensing', where the optical transmission of a solution containing rotating linear chains of magnetic nanobeads was used to detect biomolecules with pM-level sensitivity with a dynamic range of more than four orders of magnitude. Our research on the synthesis and applications of nanoparticles is particularly suitable for point of care diagnostics. PMID:20935358
Sandhu, Adarsh; Handa, Hiroshi; Abe, Masanori
Background Emergency medicine (EM) is a growing specialty in Colombia with five residency programs in the country. EM leadership is interested in incorporating point-of-care (POC) ultrasound into a standardized national EM residency curriculum. This study is a nationwide survey of Colombian EM residents designed to explore the current state of POC ultrasound use within EM residencies and examine specific barriers preventing its expansion. Methods We conducted a mix-methodology study of all available current EM residents in the five EM residencies in Colombia. The quantitative survey assessed previous ultrasound experience, current use of various applications, desire for further training, and perceived barriers to expanded use. Focus group discussions (FGDs) were conducted with current EM residents to gather additional qualitative insight into their practice patterns and perceived barriers to clinician-performed ultrasound. Results Sixty-nine EM residents completed the quantitative survey, a response rate of 85% of all current EM residents in Colombia; 52% of resident respondents had previously used ultrasound during their training. Of these, 58% indicated that they had performed <10 scans and 17% reported >40 scans. The most frequently used applications indicated by respondents were trauma, obstetrics, and procedures including vascular access. A quarter indicated they had previously received some ultrasound training, but almost all expressed an interest in learning more. Significant barriers included lack of trained teachers (indicated by 78% of respondents), absence of machines (57%), and limited time (41%). In FGDs, the barriers identified were inter-specialty conflicts over the control of ultrasonography, both institutionally and nationally, and program-specific curriculum decisions to include POC ultrasound. Conclusion While currently limited in their access, EM residents in Colombia have a strong interest in integrating POC ultrasound into their training. Current barriers to expanded use include traditional barriers such as a lack of equipment seen in many developing countries, as well as inter-specialty conflicts typical of developed countries. Further collaboration is underway to help overcome these obstacles and integrate POC ultrasound into Colombian EM residency training.
Background Measurement of blood hemoglobin (Hb) concentration is a routine procedure. Using a non-invasive point-of-care device reduces pain and discomfort for the patient and allows time saving in patient care. The aims of the present study were to assess the concordance of Hb levels obtained non-invasively with the Pronto-7 monitor (version 2.1.9, Masimo Corporation, Irvine, USA) or with the NBM-200MP monitor (Orsense, Nes Ziona, Israel) and the values obtained from the usual colorimetric method using blood samples and to determine the source of discordance. Methods and Findings We conducted two consecutive prospective open trials enrolling patients presenting in the emergency department of a university hospital. The first was designed to assess Pronto-7™ and the second NBM-200MP™. In each study, the main outcome measure was the agreement between both methods. Independent factors associated with the bias were determined using multiple linear regression. Three hundred patients were prospectively enrolled in each study. For Pronto-7™, the absolute mean difference was 0.56 g.L?1 (95% confidence interval [CI] 0.41 to 0.69) with an upper agreement limit at 2.94 g.L?1 (95% CI [2.70;3.19]), a lower agreement limit at -1.84 g.L?1 (95% CI [-2.08;-1.58]) and an intra-class correlation coefficient at 0.80 (95% CI [0.74;0.84]). The corresponding values for the NBM-200MP™ were 0.21 [0.02;0.39], 3.42 [3.10;3.74], -3.01 [-3.32;-2.69] and 0.69 [0.62;0.75]. Multivariate analysis showed that age and laboratory values of hemoglobin were independently associated with the bias when using Pronto-7™, while perfusion index and laboratory value of hemoglobin were independently associated with the bias when using NBM-200MP™. Conclusion Despite a relatively limited bias in both cases, the large limits of agreement found in both cases render the clinical usefulness of such devices debatable. For both devices, the bias is independently and inversely associated with the true value of hemoglobin. Trial Registration ClinicalTrials.gov NCT01321580 NCT01321593
Gayat, Etienne; Aulagnier, Jerome; Matthieu, Emmanuel; Boisson, Mireille; Fischler, Marc
A novel innovative approach towards a marketable lab-on-chip system for point-of-care in vitro diagnostics is reported. In a consortium of seven Fraunhofer Institutes a lab-on-chip system called "Fraunhofer ivD-platform" has been established which opens up the possibility for an on-site analysis at low costs. The system features a high degree of modularity and integration. Modularity allows the adaption of common and established assay types of various formats. Integration lets the system move from the laboratory to the point-of-need. By making use of the microarray format the lab-on-chip system also addresses new trends in biomedicine. Research topics such as personalized medicine or companion diagnostics show that multiparameter analyses are an added value for diagnostics, therapy as well as therapy control. These goals are addressed with a low-cost and self-contained cartridge, since reagents, microfluidic actuators and various sensors are integrated within the cartridge. In combination with a fully automated instrumentation (read-out and processing unit) a diagnostic assay can be performed in about 15 min. Via a user-friendly interface the read-out unit itself performs the assay protocol, data acquisition and data analysis. So far, example assays for nucleic acids (detection of different pathogens) and protein markers (such as CRP and PSA) have been established using an electrochemical read-out based on redoxcycling or an optical read-out based on total internal reflectance fluorescence (TIRF). It could be shown that the assay performance within the cartridge is similar to that found for the same assay in a microtiter plate. Furthermore, recent developments are the integration of sample preparation and polymerase chain reaction (PCR) on-chip. Hence, the instrument is capable of providing heating-and-cooling cycles necessary for DNA-amplification. In addition to scientific aspects also the production of such a lab-on-chip system was part of the development since this heavily affects the success of a later market launch. In summary, the Fraunhofer ivD-platform covers the whole value chain ranging from microfluidics, material and polymer sciences, assay and sensor development to the production and assembly design. In this consortium the gap between diagnostic needs and available technologies can be closed. PMID:22038328
Schumacher, Soeren; Nestler, Jörg; Otto, Thomas; Wegener, Michael; Ehrentreich-Förster, Eva; Michel, Dirk; Wunderlich, Kai; Palzer, Silke; Sohn, Kai; Weber, Achim; Burgard, Matthias; Grzesiak, Andrzej; Teichert, Andreas; Brandenburg, Albrecht; Koger, Birgit; Albers, Jörg; Nebling, Eric; Bier, Frank F
We present 2 cases of asymptomatic patients who were found to have raised and blurred optic discs on physical examination, suggestive of papilledema. Evaluation in the emergency department revealed 2 well-appearing children with normal vital signs and neurologic evaluation results, without symptoms of increased intracranial pressure. Point-of-care ocular ultrasonography was performed on both children, demonstrating calcification at the optic nerve, which is diagnostic of optic disc drusen. Optic disc drusen is caused by the deposition of calcified axonal debris and is often buried within the optic disc in pediatric patients. It can cause some changes in visual acuity and visual fields, but patients who are otherwise asymptomatic can be easily diagnosed through point-of-care ultrasound, thereby sparing patients an aggressive workup if their clinical picture is otherwise reassuring. PMID:24987997
Braun, Alanna; Doniger, Stephanie J
Many individuals infected with the human immunodeficiency virus (HIV), especially children in African countries, die of co-infections with Mycobacterium tuberculosis (MTB) (coinfection rate: 50%) or Pneumocystis carinii pneumonia (PCP) (coinfection rate: 81%). The present proposal describes a rapid, portable, low-cost, multiplexed point-of-care diagnostic technique for simultaneously detecting HIV, MTB, and PCP. This technique incorporates a creative micro-device (hardware) and a loop-mediated isothermal amplification strategy (software). PMID:24209377
Xu, Lingjia; Kong, Jilie
Interoperability at the device and system levels has the potential to improve ease of use for point-of-care systems while lowering the cost of these systems. To this end, we developed a prototype wearable monitoring system based on interoperability standards that demonstrates plug-and-play wireless connectivity between the system components. The system utilizes both device-level (IEEE 11073, Bluetooth) and system-level (Health Level
Steve Warren; Jeffrey Lebak; Jianchu Yao
The field of centrifugal microfluidics aims to miniaturize common biochemical assays onto specialized discs (CDs). By the exploitation of the centrifugal force, centrifugal microfluidics CDs do not require the syringe pumps that stationary microfluidic platforms require. This paper describes the development of a low-cost and portable controller device that is capable of performing centrifugal microfluidics at the point-of-care (POC). Overall,
P. Jahanshahi; S. Z. M. Dawal; Fatimah Ibrahim; A. A. Nozari; Norhayati Soin
In this paper the methodology of designing a genomic-based point-of-care diagnostic system composed of a microfluidic Lab-On-Chip, algorithms for microarray image information extraction and knowledge modeling of clinico-genomic patient data is presented. The data are processed by genome wide association studies for two complex diseases: rheumatoid arthritis and multiple sclerosis. Respecting current technological limitations of autonomous molecular-based lab-on-chip systems the
Fanis G. Kalatzis; Nikolaos Giannakeas; Themis P. Exarchos; Leandro Lorenzelli; Andrea Adami; Massimiliano Decarli; Sara Lupoli; Fabio Macciardi; Sofia Markoula; Ioannis Georgiou; Dimitrios I. Fotiadis
ObjectiveTo evaluate: (1) the effectiveness of wireless handheld computers for online information retrieval in clinical settings; (2) the role of MEDLINE® in answering clinical questions raised at the point of care.DesignA prospective single-cohort study: accompanying medical teams on teaching rounds, five internal medicine residents used and evaluated MD on Tap, an application for handheld computers, to seek answers in real
Susan E. Hauser; Dina Demner-Fushman; Joshua L. Jacobs; Susanne M. Humphrey; Glenn Ford; George R. Thoma
This study used both survey and interview questionnaires. It was designed to assess the feasibility, usability, and utility of two point-of-care tools especially prepared with information relevant for dementia care by staff nurses in a small, a medium-sized, and a large nursing home in Florida. Twenty-five LPN or RN nurses were recruited for the study of their use of one
Syeda S. Qadri; Jia Wang; Jorge G. Ruiz; Bernard A. Roos
Background Point Of Care (POC) meters are a relatively less invasive and rapid method for monitoring of Prothrombin Time\\/Interational\\u000a Normalized Ratio (PT\\/INR) in patients on anticoagulant therapy. The reliability of results obtained with meters, however,\\u000a needs to be affirmed and their accuracy needs to be assessed by comparing with standard laboratory analysis. We assessed the\\u000a Coaguchek XS (Roche) PT\\/INR meter for
Ramakrishnan Lakshmy; A. Sampath Kumar
OBJECTIVESThe purpose of this study was to compare the results of physical examinations (PEs) performed by board-certified cardiologists with the results of point-of-care (POC) echocardiography in a group of patients with cardiovascular disease.BACKGROUNDAlthough cardiovascular PE is crucial in the evaluation of patients with suspected heart disease, the skills required to diagnose abnormal cardiovascular findings have been declining. Echocardiography is a
Kirk T Spencer; Allen S Anderson; Ajay Bhargava; Amy C Bales; Matthew Sorrentino; Kathy Furlong; Roberto M Lang
INTRODUCTION: To obtain strict glucose regulation, an accurate and feasible bedside glucometry method is essential. We evaluated three different types of point-of-care glucometry in seriously ill intensive care unit (ICU) patients. The study was performed as a single-centre, prospective, observational study in a 12-bed medical ICU of a university hospital. METHODS: Patients with an expected ICU stay of more than
Anouk M Corstjens; Jack JM Ligtenberg; Iwan CC van der Horst; Rob Spanjersberg; Joline SW Lind; Jaap E Tulleken; John HJM Meertens; Jan G Zijlstra
The miniaturization of biosensors using microfluidics has potential in enabling the development of point-of-care devices, with the added advantages of reduced time and cost of analysis with limits-of-detection comparable to those obtained through traditional laboratory techniques. Interfacing microfluidic devices with the external world can be difficult especially in aspects involving fluid handling and the need for simple sample insertion that avoids special equipment or trained personnel. In this work we present a point-of-care prototype system by integrating capillary microfluidics with a microfabricated photodiode array and electronic instrumentation into a hand-held unit. The capillary microfluidic device is capable of autonomous and sequential fluid flow, including control of the average fluid velocity at any given point of the analysis. To demonstrate the functionality of the prototype, a model chemiluminescence ELISA was performed. The performance of the integrated optical detection in the point-of-care prototype is equal to that obtained with traditional bench-top instrumentation. The photodiode signals were acquired, displayed and processed by a simple graphical user interface using a computer connected to the microcontroller through USB. The prototype performed integrated chemiluminescence ELISA detection in about 15 min with a limit-of-detection of ?2 nM with an antibody-antigen affinity constant of ?2×10(7) M(-1). PMID:24607579
Novo, P; Chu, V; Conde, J P
The recent revolution in digital technologies and information processing methods present important opportunities to transform the way optical imaging is performed, particularly toward improving the throughput of microscopes while at the same time reducing their relative cost and complexity. Lensfree computational microscopy is rapidly emerging toward this end, and by discarding lenses and other bulky optical components of conventional imaging systems, and relying on digital computation instead, it can achieve both reflection and transmission mode microscopy over a large field-of-view within compact, cost-effective and mechanically robust architectures. Such high throughput and miniaturized imaging devices can provide a complementary toolset for telemedicine applications and point-of-care diagnostics by facilitating complex and critical tasks such as cytometry and microscopic analysis of e.g., blood smears, Pap tests and tissue samples. In this article, the basics of these lensfree microscopy modalities will be reviewed, and their clinically relevant applications will be discussed.
Isikman, Serhan O.; Greenbaum, Alon; Lee, Myungjun; Bishara, Waheb; Mudanyali, Onur; Su, Ting-Wei; Ozcan, Aydogan
Background In Belgium, the construction of a national electronic point-of-care information service, EBMPracticeNet, was initiated in 2011 to optimize quality of care by promoting evidence-based decision-making. The collaboration of the government, health care providers, evidence-based medicine (EBM) partners, and vendors of electronic health records (EHR) is unique to this project. All Belgian health care professionals get free access to an up-to-date database of validated Belgian and nearly 1000 international guidelines, incorporated in a portal that also provides EBM information from other sources than guidelines, including computerized clinical decision support that is integrated in the EHRs. Objective The objective of this paper was to describe the development strategy, the overall content, and the management of EBMPracticeNet which may be of relevance to other health organizations creating national or regional electronic point-of-care information services. Methods Several candidate providers of comprehensive guideline solutions were evaluated and one database was selected. Translation of the guidelines to Dutch and French was done with translation software, post-editing by translators and medical proofreading. A strategy is determined to adapt the guideline content to the Belgian context. Acceptance of the computerized clinical decision support tool has been tested and a randomized controlled trial is planned to evaluate the effect on process and patient outcomes. Results Currently, EBMPracticeNet is in "work in progress" state. Reference is made to the results of a pilot study and to further planned research including a randomized controlled trial. Conclusions The collaboration of government, health care providers, EBM partners, and vendors of EHRs is unique. The potential value of the project is great. The link between all the EHRs from different vendors and a national database held on a single platform that is controlled by all EBM organizations in Belgium are the strengths of EBMPracticeNet.
The integration of information technology into daily patient care potentially provides a means to standardize care and enable continuous quality improvement through improved communication among care teams. A 2-month observational study was conducted on 38 residents with pressure ulcers at a 51-bed skilled nursing facility to rate the Ease of Use and Wound Management Effectiveness of a point-of-care electronic wound documentation system. Nine nurses evaluated the use of handheld "smart phone" devices equipped with a digital camera to document pressure ulcer assessment and treatment at point of care. Ease of Use (five items) was scored on a 5-point Likert scale (5 = very easy); Wound Management Effectiveness (eight items) was scored on a 5-point Likert scale (5 = very effective). Statistically significant mean changes in nurses' ratings were found for baseline compared to 2-month follow-up by paired t-test. Ease of Use ratings across the five criteria increased from an overall mean of 3.3 at baseline to 4.7 at follow-up (P = 0.5), while Wound Management Effectiveness increased from an overall mean of 3.3 at baseline to 4.4 at follow-up (P = 0.5) . The greatest gains for single items were reviewing wound progress (mean difference = 2.35; P = 0.000) and recognizing changes in wound status (mean difference = 1.78; P = 0.001) within the Ease of Use and Wound Management Effectiveness scales, respectively. The smallest change occurred in reading charts and notes (mean difference = 0.89) and ability to determine resident's risk level (mean difference = 0.39). Further research is needed to assess use of a wound documentation system in this and other settings, as well as to ascertain validity and reliability. PMID:22391956
Florczak, Beth; Scheurich, Anne; Croghan, John; Sheridan, Philip; Kurtz, Debra; McGill, William; McClain, Bonny
There is controversy regarding needle aspiration for primary spontaneous pneumothorax (PSP), with contradictory recommendations between the American College of Chest Physicians consensus statement (2001), which suggests that needle aspiration has little place in the management of PSP, and the British Thoracic Society guidelines (2010), which recommend that needle aspiration be attempted first for all cases of PSP where drainage is deemed necessary. Studies have shown that there is no significant difference between needle aspiration and tube thoracostomy with regard to safety, rates of immediate success, and early failure and has the advantages of decreasing pain and reducing rates of hospital admission and duration of hospital stay compared with tube thoracostomy. Point-of-care ultrasound (US) can facilitate needle aspiration by decreasing the risk of complications and detect pneumothorax resolution during or re-expansion after the procedure. This is a case series where the sonographic finding of the “lung point” on point-of-care US was used to facilitate needle aspiration to monitor pneumothorax resolution during or re-expansion after the procedure. We report 3 cases of PSP in adolescents presenting to the pediatric emergency department (ED), where needle aspiration was safely performed by using US to track the sonographic finding of the lung point. This technique allows the determination of pneumothorax resolution or re-expansion in real time. Point-of-care US may assist in the evaluation and management of spontaneous pneumothorax in the pediatric ED. Ultrasound-assisted needle aspiration may be a safe and less painful option for pediatric ED patients with PSP. PMID:24360316
Ng, Carrie; Tsung, James W
Background Effective knowledge translation at the point of care requires that clinicians quickly find correct answers to clinical questions, and that they have appropriate confidence in their answers. Web-based knowledge resources can facilitate this process. Objective The objective of our study was to evaluate a novel Web-based knowledge resource in comparison with other available Web-based resources, using outcomes of accuracy, time, and confidence. Methods We conducted a controlled, crossover trial involving 59 practicing clinicians. Each participant answered questions related to two clinical scenarios. For one scenario, participants used a locally developed Web-based resource, and for the second scenario, they used other self-selected Web-based resources. The local knowledge resource (“AskMayoExpert”) was designed to provide very concise evidence-based answers to commonly asked clinical questions. Outcomes included time to a correct response with at least 80% confidence (primary outcome), accuracy, time, and confidence. Results Answers were more often accurate when using the local resource than when using other Web-based resources, with odds ratio 6.2 (95% CI 2.6-14.5; P<.001) when averaged across scenarios. Time to find an answer was faster, and confidence in that answer was consistently higher, for the local resource (P<.001). Overconfidence was also less frequent with the local resource. In a time-to-event analysis, the chance of responding correctly with at least 80% confidence was 2.5 times greater when using the local resource than with other resources (95% CI 1.6-3.8; P<.001). Conclusions Clinicians using a Web-based knowledge resource designed to provide quick, concise answers at the point of care found answers with greater accuracy and confidence than when using other self-selected Web-based resources. Further study to improve the design and implementation of knowledge resources may improve point of care learning.
Enders, Felicity; Linderbaum, Jane A; Zwart, Dale; Lloyd, Farrell J
Executive Summary Subject of the Evidence-Based Analysis The purpose of this evidence based analysis report is to examine the safety and effectiveness of point-of-care (POC) international normalized ratio (INR) monitoring devices for patients on long-term oral anticoagulation therapy (OAT). Clinical Need: Target Population and Condition Long-term OAT is typically required by patients with mechanical heart valves, chronic atrial fibrillation, venous thromboembolism, myocardial infarction, stroke, and/or peripheral arterial occlusion. It is estimated that approximately 1% of the population receives anticoagulation treatment and, by applying this value to Ontario, there are an estimated 132,000 patients on OAT in the province, a figure that is expected to increase with the aging population. Patients on OAT are regularly monitored and their medications adjusted to ensure that their INR scores remain in the therapeutic range. This can be challenging due to the narrow therapeutic window of warfarin and variation in individual responses. Optimal INR scores depend on the underlying indication for treatment and patient level characteristics, but for most patients the therapeutic range is an INR score of between 2.0 and 3.0. The current standard of care in Ontario for patients on long-term OAT is laboratory-based INR determination with management carried out by primary care physicians or anticoagulation clinics (ACCs). Patients also regularly visit a hospital or community-based facility to provide a venous blood samples (venipuncture) that are then sent to a laboratory for INR analysis. Experts, however, have commented that there may be under-utilization of OAT due to patient factors, physician factors, or regional practice variations and that sub-optimal patient management may also occur. There is currently no population-based Ontario data to permit the assessment of patient care, but recent systematic reviews have estimated that less that 50% of patients receive OAT on a routine basis and that patients are in the therapeutic range only 64% of the time. Overview of POC INR Devices POC INR devices offer an alternative to laboratory-based testing and venipuncture, enabling INR determination from a fingerstick sample of whole blood. Independent evaluations have shown POC devices to have an acceptable level of precision. They permit INR results to be determined immediately, allowing for more rapid medication adjustments. POC devices can be used in a variety of settings including physician offices, ACCs, long-term care facilities, pharmacies, or by the patients themselves through self-testing (PST) or self-management (PSM) techniques. With PST, patients measure their INR values and then contact their physician for instructions on dose adjustment, whereas with PSM, patients adjust the medication themselves based on pre-set algorithms. These models are not suitable for all patients and require the identification and education of suitable candidates. Potential advantages of POC devices include improved convenience to patients, better treatment compliance and satisfaction, more frequent monitoring and fewer thromboembolic and hemorrhagic complications. Potential disadvantages of the device include the tendency to underestimate high INR values and overestimate low INR values, low thromboplastin sensitivity, inability to calculate a mean normal PT, and errors in INR determination in patients with antiphospholipid antibodies with certain instruments. Although treatment satisfaction and quality of life (QoL) may improve with POC INR monitoring, some patients may experience increased anxiety or preoccupation with their disease with these strategies. Evidence-Based Analysis Methods Research Questions 1. Effectiveness Does POC INR monitoring improve clinical outcomes in various settings compared to standard laboratory-based testing? Does POC INR monitoring impact patient satisfaction, QoL, compliance, acceptability, convenience compared to standard laboratory-based INR determination? Settings include primary care settings with use of POC INR dev
We evaluated a commercial point-of-care circulating cathodic antigen (POC-CCA) test for assessing Schistosoma mansoni infection prevalence in areas at risk. Overall, 4,405 school-age children in Cameroon, Côte d'Ivoire, Ethiopia, Kenya, and Uganda provided urine for POC-CCA testing and stool for Kato-Katz assays. By latent class analysis, one POC-CCA test was more sensitive (86% versus 62%) but less specific (72% versus ?100%) than multiple Kato-Katz smears from one stool. However, only 1% of POC-CCA tests in a non-endemic area were false positives, suggesting the latent class analysis underestimated the POC-CCA specificity. Multivariable modeling estimated POC-CCA as significantly more sensitive than Kato-Katz at low infection intensities (< 100 eggs/gram stool). By linear regression, 72% prevalence among 9–12 year olds by POC-CCA corresponded to 50% prevalence by Kato-Katz, whereas 46% POC-CCA prevalence corresponded to 10% Kato-Katz prevalence. We conclude that one urine POC-CCA test can replace Kato-Katz testing for community-level S. mansoni prevalence mapping.
Colley, Daniel G.; Binder, Sue; Campbell, Carl; King, Charles H.; Tchuem Tchuente, Louis-Albert; N'Goran, Eliezer K.; Erko, Berhanu; Karanja, Diana M. S.; Kabatereine, Narcis B.; van Lieshout, Lisette; Rathbun, Stephen
Welcome to the workshop on 'Improving Health Care Accessibility Through Point-of-Care Technologies.' The meeting is jointly sponsored by the National Institutes of Health (National Institute of Biomedical Imaging and Bioengineering and National Heart, Lun...
Introduction Stavudine is still widely used in under-resourced settings such as Malawi due to its low price. It frequently causes peripheral neuropathy and lipodystrophy and increases the risk of lactic acidosis and other high lactate syndromes. Methods We studied the association of longitudinal lactate levels, obtained by routine, 3-monthly point-of-care monitoring, with peripheral neuropathy, lipodystrophy and high lactate syndromes in adult Malawians who were in the second year of stavudine containing antiretroviral therapy (ART). Results Point-of-care lactate measurements were feasible in a busy urban ART clinic. Of 1170 lactate levels collected from 253 patients over the course of one year, 487 (41.8%) were elevated (>2.2mg/dl), 58 (5.0%) were highly elevated (>3.5mg/dl). At least one elevated lactate level occurred in 210 (83.0%) of patients and sustained hyperlactatemia in 65 (26.4%). In random effects analyses lipodystrophy and peripheral neuropathy were associated with higher lactate levels. Only five patients developed high lactate syndromes (one lactic acidosis) of whom no preceding lactate measurements were available because events had started before enrolment. Lactate levels significantly decreased over time and no high lactate syndromes were observed after the 15th month on ART. Conclusion Lipodystrophy and peripheral neuropathy were associated with higher lactate levels. Lactate levels decreased over time, coinciding with absence of new high lactate syndromes after the 15th month on ART.
Chagoma, Newton; Mallewa, Jane; Kaunda, Symon; Njalale, Yasin; Kampira, Elizabeth; Mukaka, Mavuto; Heyderman, Robert S; van Oosterhout, Joep J
Diagnosis of pulmonary tuberculosis (TB) remains a challenge in the pediatric population because of the lack of sputum production for laboratory analysis. Chest radiography is used in the diagnosis of pulmonary TB and the hallmark of diagnosis is the demonstration of hilar or mediastinal lymphadenopathy. Point-of-care sonography of the mediastinum is an alternative to chest radiography in detection of tuberculous lymph nodes. In the rural district health care setting US is often the most commonly available imaging modality and its mobility makes it possible to examine patients at the point of care, reducing the need for patients to travel to a regional hospital to acquire a chest radiograph. We developed and used a simplified technique for performing mediastinal sonography in a pilot study of 30 children (age 0 to 13 years) with proven or suspected TB. We can report that the procedure was successful in demonstrating the anterior mediastinal anatomy and predefined zones in all 30 children. We also recorded lymphadenopathy in 12 children. This report describes our procedural methods and initial results. PMID:24854938
Moseme, Tsepo; Andronikou, Savvas
The impact of detecting multiple infectious diseases simultaneously at point-of-care with good sensitivity, specificity, and reproducibility would be enormous for containing the spread of diseases in both resource-limited and rich countries. Many barcoding technologies have been introduced for addressing this need as barcodes can be applied to detecting thousands of genetic and protein biomarkers simultaneously. However, the assay process is not automated and is tedious and requires skilled technicians. Barcoding technology is currently limited to use in resource-rich settings. Here we used magnetism and microfluidics technology to automate the multiple steps in a quantum dot barcode assay. The quantum dot-barcoded microbeads are sequentially (a) introduced into the chip, (b) magnetically moved to a stream containing target molecules, (c) moved back to the original stream containing secondary probes, (d) washed, and (e) finally aligned for detection. The assay requires 20 min, has a limit of detection of 1.2 nM, and can detect genetic targets for HIV, hepatitis B, and syphilis. This study provides a simple strategy to automate the entire barcode assay process and moves barcoding technologies one step closer to point-of-care applications. PMID:23438061
Gao, Yali; Lam, Albert W Y; Chan, Warren C W
The ability to conveniently and immediately test and diagnose in a diverse and rapidly changing environment is critical for field diagnostics. Smart biomedical sensors employ many different diagnostic/therapeutic methodologies; however, an ideal system wo...
A. S. Finch D. A. Sarkes J. R. Bickford M. A. Conn M. B. Coppock
This paper describes a new diagnostic instrument which uses magnetic modulation of an optical signal to rapidly measure whole blood Prothrombin time. The new instrument improves diagnosing and level monitoring by allowing accurate, rapid, low cost near patient testing. The measurement system consists of five major components: a control system; a user interface, a disposable-strip laminate architecture with proprietary chemistry
Greg P. Carpenter; T. Gary Neel; James R. Parker
Breast cancer-related lymphedema (BCRL) can be irreversible with profound negative impact on patients' quality of life. Programs that provide screening and active surveillance for BCRL are essential to determine whether early detection and intervention influences the course of lymphedema development. Established methods of quantitatively assessing lymphedema at early stages include "volume" methods such as perometry and bioimpedance spectroscopy. Here we demonstrate 1) Use of topographical techniques analogous to those used in corneal topography 2) Development of point-of-care lymphedema detection and characterization based on off-the-shelf hardward 3) The role of subsurface imaging 4) Multimodal diagnostics and integration yielding higher sensitivity/ specificity.
Sayegh, Samir I.; Taghian, Alphonse
To compare images obtained using two linear transducers with a different range of frequencies, and to determine if there is a significant difference in the quality of images between the two transducers for medical decision-making. This was a single-blinded, cross-sectional study at an academic medical center. Twenty-five emergency medicine clinical scenarios with ultrasound images (using both 10-5 and 14-5 MHz transducers) covering a variety of point-of-care ultrasound applications were presented to four emergency physician sonographers. They were blinded to the study hypothesis and type of the transducer used to obtain the images. On a scale of 1-10, the mean image quality rating for 10-5 MHz transducer was 7.09 (95 % CI 6.73-7.45) and 6.49 (95 % CI 5.99-6.99) for 14-5 MHz transducer. In the majority of cases (84 %, 95 % CI 75.7-92.3 %), sonographers indicated that images obtained with a 10-5 MHz transducer were satisfactory for medical decision-making. They preferred images obtained with a 10-5 MHz transducer over 14-5 MHz transducer in 39 % (95 % CI 30-50 %) of cases. The images obtained with a 14-5 MHz transducer were preferred over 10-5 MHz transducer in only 16 % (95 % CI 7.7-24.3 %) of the cases. The 14-5 MHz transducer has a slight advantage over 10-5 MHz transducer for ocular, upper airway, and musculoskeletal (tendon) ultrasound applications. A 10-5 MHz linear transducer is adequate to obtain images that can be used for medical decision-making for a variety of point-of-care ultrasound applications. PMID:24186196
Electronic medical record systems and clinical practice guideline (CPG) support applications are emerging in the clinical environment to document and support care. Applications which integrate online documentation with CPG are often complex systems bound to a proprietary infrastructure and as such, can be difficult to adapt to changing care guidelines. This paper describes integration of point-of-care clinical documentation to an Internet-based CPG system that was easily modified, utilized available software resources, and separated patient information from CPG. The system combined a text-based encounter documentation tool, Inbox, with a web-based CPG system, SIEGFRIED (System for Interactive Electronic Guidelines with Feedback and Resources for Instructional and Educational Development), which interactively presented care guidelines to providers. Age-specific well child care documentation templates were developed using Inbox for point-of-care documentation. SIEGFRIED contained the knowledge base of child safety education guidelines and executed independent of the program presenting the guidelines. The CPG were accessed from within the documentation template via an Internet hyperlink. Patient chart evaluation indicated that 77% of safety topics were reviewed and 32% of the charts contained documentation indicating all the safety topics were reviewed. Last, routine use of the Inbox-SIEGFRIED system was not realized due to the clinical time constraints and workload of the medical providers, and lack of data entry experience. A user survey indicated time cost (network access and software execution) were negative aspects of the system. However, the system function was highly regarded and the Internet-based patient education materials were described as useful and accurate. In summary, the system was functional, met original development goals, and provided valuable patient education materials; however, routine system use was prevented by time requirements. We recommend further development be oriented towards integrating the identified beneficial components of the system into clinician workflow. Images Figure 1
Porcelli, P. J.; Lobach, D. F.
The purpose of this study was to establish reference intervals for prothrombin time (PT) and activated partial prothrombin time (aPTT) in healthy rabbits using two different point-of-care analysers (Idexx Coag DX and MS Quick Vet Coag Combo). These intervals would be useful in the diagnosis of coagulopathies and in the determination of coagulation status in critical patients. We are unaware of reports of coagulation values in pet rabbits. Blood samples were analysed from 81 clinically healthy pet rabbits under three years of age (49 females and 32 males). The reference intervals were as follows (non-parametric method for the MS Quick Vet Coag Combo and Box-Cox Robust method for the Idexx Coag DX, p<0.05 limit for statistical significance): PT (MS Quick Vet Coag Combo)=N=33, 17.2-28.5; PT (Idexx Coag DX)=N=48, 10.0-14.8, aPTT (MS Quick Vet Coag Combo)=N=33, 103.2-159.2 and aPTT (Idexx Coag DX)=N=48, 104.2-159.1. PT was significantly longer using the MS Quick Vet Coag Combo. aPTT was significantly shorter with the MS Quick Vet Coag Combo. On each type of analyser, there was no significant difference between sexes and blood sampling sites. A significant difference was present for the use or not of anaesthesia with the MS Quick Vet Coag Combo analyser. This study on healthy pet rabbits will be useful in point-of-care diagnosis of coagulopathies. PMID:24722233
Mentré, V; Bulliot, C; Linsart, A; Ronot, P
PCR detection of human immunodeficiency virus type 1 (HIV-1) proviral DNA is the method recommended for use for the diagnosis of HIV-1 infection in infants in limited-resource settings. Currently, testing must be performed in central laboratories, which are usually located some distance from health care facilities. While the collection and transportation of samples, such as dried blood spots, has improved test accessibility, the results are often not returned for several weeks. To enable PCR to be performed at the point of care while the mothers wait, we have developed a vertical filtration method that uses a separation membrane and an absorbent pad to extract cellular DNA from whole blood in less than 2 min. Cells are trapped in the separation membrane as the specimen is collected, and then a lysis buffer is added. The membrane retains the DNA, while the buffer washes away PCR inhibitors, which get wicked into the absorbent blotter pad. The membrane containing the entrapped DNA is then added to the PCR mixture without further purification. The method demonstrates a high degree of reproducibility and analytical sensitivity and allows the quantification of as few as 20 copies of HIV-1 proviral DNA from 100 microl of blood. In a blinded study with 182 longitudinal samples from infants (ages, 0 to 72 weeks) obtained from the Women and Infants Transmission Study, our assay demonstrated a sensitivity of 99% and a specificity of 100%. PMID:19644129
Jangam, Sujit R; Yamada, Douglas H; McFall, Sally M; Kelso, David M
Severe malaria is frequently managed without access to laboratory testing. We report on the performance of point-of-care tests used to guide the management of a cohort of 179 children with severe malaria in a resource-limited Ugandan hospital. Correlation coefficients between paired measurements for glucose (i-STAT and One Touch Ultra), lactate (i-STAT and Lactate Scout), and hemoglobin (Hb; laboratory and i-STAT) were 0.86, 0.85, and 0.73, respectively. The OneTouch Ultra glucometer readings deviated systematically from the i-STAT values by +1.7 mmol/L. Lactate Scout values were systematically higher than i-STAT by +0.86 mmol/L. Lactate measurements from either device predicted subsequent mortality. Hb estimation by the i-STAT instrument was unbiased, with upper and lower limits of agreement of -34 and +34 g/L, and it was 91% sensitive and 89% specific for the diagnosis of severe anemia (Hb < 50 g/L). New commercially available bedside diagnostic tools, although imperfect, may expedite clinical decision-making in the management of critically ill children in resource-constrained settings. PMID:24591431
Hawkes, Michael; Conroy, Andrea L; Opoka, Robert O; Namasopo, Sophie; Liles, W Conrad; John, Chandy C; Kain, Kevin C
We propose the use of a potentiometric biosensor that incorporates the efficient and specific molecular imprinting (MI) method with a self-assembled monolayer (SAM). We first tested the biosensor using carcinoembryonic antigen, CEA, a biomarker associated with pancreatic cancer. No change in detection efficiency was observed when detection was performed in the presence of 100% serum albumin, indicating that the sensor is able to discriminate for the template analyte even in concentrated solution of similar substances. Computer simulations of the protein structure were performed in order to estimate the changes in morphology and determine the sensitivity of the biosensor to conformational changes in the proteins. We found that even small changes in PH can generate rotation of the surface functional groups, without significant change in the morphology. Yet, the results show that only when the detection and imprinting conditions are similar, robust signals occurs. Hence we concluded that both morphology and surface chemistry play a role in the recognition.
Yu, Yingjie; Rafailovich, Miriam; Wang, Yantian; Ranjbaran, Alina; Wang, Tom; Nam, David
We propose the use of a potentiometric biosensor that incorporates the efficient and specific molecular imprinting (MI) method with a self-assembled monolayer (SAM). We first tested the biosensor using carcinoembryonic antigen, CEA, a biomarker associated with pancreatic cancer. No change in detection efficiency was observed, indicating that the sensor is able to discriminate for the template analyte even in concentrated solution of similar substances. In addition, we use biosensor to discriminate normal fibrinogen and damaged fibrinogen, which is critical for the detection of bleeding disorder. Computer simulations of the protein structure were performed in order to estimate the changes in morphology and determine the sensitivity of the biosensor to conformational changes in the proteins. We found that even small changes in PH can generate rotation of the surface functional groups. Yet, the results show that only when the detection and imprinting conditions are similar, robust signals occurs. Hence we concluded that both morphology and surface chemistry play a role in the recognition.
Yu, Yingjie; Rafailovich, Miriam; Wang, Yantian; Kang, Yeona; Zhang, Lingxi; Rigas, Basil
The purpose of this study was to evaluate the diagnostic performance of a hand-held electronic glucometer (Precision Xtra; Abbott Diabetes Care Inc., Mississauga, ON, Canada) for cow-side use in dairy cattle. This device has been validated for measuring blood concentrations of ?-hydroxybutyrate in dairy cows. This study was designed to assess the accuracy of whole-blood glucose measurements from the glucose meter relative to a reference chemical analyzer in a diagnostic laboratory. Duplicate samples were taken from the same cows at the same time, into blood tubes with either the glycolysis-inhibiting preservative sodium fluoride (NaF) or without preservative. Glucometer readings were taken on whole blood with no preservative, and laboratory measurements were conducted on serum preserved with NaF. Blood samples were collected from cows between 3 wk before and 5 wk after calving, including during a glucose tolerance test conducted 1 wk before expected calving. Passing-Bablok and Bland-Altman data analyses were used to evaluate the performance of the glucometer relative to the laboratory results. A strong correlation was observed in 709 samples from 81 cows between the hand-held meter and serum from samples preserved with NaF (R(2)=0.95). Overall, 96% of measurements with the glucometer fell within the 95% confidence limits of analysis in the laboratory, although at higher-than-physiologic glucose concentrations (>5.2mmol/L) the glucometer tended to overestimate. The hand-held glucometer appears suitable for rapid measurement of glucose under field conditions in dairy cattle. PMID:23684029
Wittrock, J A M; Duffield, T F; LeBlanc, S J
Background Optimal treatment of acute ST-elevation myocardial infarction (STEMI) involves rapid diagnosis, and transfer to a cardiac centre capable of percutaneous coronary intervention (PCI) for immediate mechanical revascularisation. Successful treatment requires rapid return of perfusion to the myocardium achieved by thromboaspiration, passivation of the culprit lesion with stent scaffolding and systemic inhibition of thrombosis and platelet activation. A delicate balance exists between thrombosis and bleeding and consequently anti-thrombotic and antiplatelet treatment regimens continue to evolve. The desire to achieve reperfusion as soon as possible, in the setting of high platelet reactivity, requires potent and fast-acting anti-thrombotic/anti-platelet therapies. The associated bleeding risk may be minimised by use of short-acting anti-thrombotic intravenous agents. However, effective oral platelet inhibition is required to prevent recurrent thrombosis. The interaction between baseline platelet reactivity, timing of revascularisation and effective inhibition of thrombosis is yet to be formally investigated. Methods/Design We present a protocol for a prospective observational study in patients presenting with acute STEMI treated with primary PCI (PPCI) and receiving bolus/infusion bivalirudin and prasugrel therapy. The objective of this study is to describe variation in platelet reactivity, as measured by the multiplate platelet function analyser, at presentation, the end of the PPCI procedure and 1, 2, & 24 hours post-procedure. We intend to assess the prevalence of high residual platelet reactivity within 24 hours of PPCI in acute STEMI patients receiving prasugrel and bivalirudin. Additionally, we will investigate the association between high platelet reactivity before and after PPCI and the door-to-procedure completion time. This is a single centre study with a target sample size of 108 participants. Discussion The baseline platelet reactivity on presentation with a STEMI may impact on the effect of acute anti-thrombotic and anti-platelet therapy and expose patients to a heightened risk of bleeding or ongoing thrombosis. This study will define the baseline variation in platelet reactivity in a population of patients experiencing acute STEMI and assess the pharmacodynamic response to combined treatment with bivalirudin and prasugrel. The data obtained from this trial will be hypothesis generating for future trials testing alternative pharmacotherapies in the acute phase of treatment for STEMI. Trial registration This study has approval from Wiltshire research ethics committee (10/H0106/87) and is registered with current controlled trials (http://www.controlled-trials.com/ISRCTN82257414).
IMPORTANCE In making decisions about patient care, clinicians raise questions and are unable to pursue or find answers to most of them. Unanswered questions may lead to suboptimal patient care decisions. OBJECTIVE To systematically review studies that examined the questions clinicians raise in the context of patient care decision making. DATA SOURCES MEDLINE (from 1966), CINAHL (from 1982), and Scopus (from 1947), all through May 26, 2011. STUDY SELECTION Studies that examined questions raised and observed by clinicians (physicians, medical residents, physician assistants, nurse practitioners, nurses, dentists, and care managers) in the context of patient care were independently screened and abstracted by 2 investigators. Of 21?710 citations, 72 met the selection criteria. DATA EXTRACTION AND SYNTHESIS Question frequency was estimated by pooling data from studies with similar methods. MAIN OUTCOMES AND MEASURES Frequency of questions raised, pursued, and answered and questions by type according to a taxonomy of clinical questions. Thematic analysis of barriers to information seeking and the effects of information seeking on decision making. RESULTS In 11 studies, 7012 questions were elicited through short interviews with clinicians after each patient visit. The mean frequency of questions raised was 0.57 (95% CI, 0.38-0.77) per patient seen, and clinicians pursued 51% (36%-66%) of questions and found answers to 78% (67%-88%) of those they pursued. Overall, 34% of questions concerned drug treatment, and 24% concerned potential causes of a symptom, physical finding, or diagnostic test finding. Clinicians' lack of time and doubt that a useful answer exists were the main barriers to information seeking. CONCLUSIONS AND RELEVANCE Clinicians frequently raise questions about patient care in their practice. Although they are effective at finding answers to questions they pursue, roughly half of the questions are never pursued. This picture has been fairly stable over time despite the broad availability of online evidence resources that can answer these questions. Technology-based solutions should enable clinicians to track their questions and provide just-in-time access to high-quality evidence in the context of patient care decision making. Opportunities for improvement include the recent adoption of electronic health record systems and maintenance of certification requirements. PMID:24663331
Del Fiol, Guilherme; Workman, T Elizabeth; Gorman, Paul N
It has recently been demonstrated that 2-aminoacetophenone (2-AA) is a chemical indicator in exhaled air/breath of Pseudomonas aeruginosa infection associated with progressive life threatening decline of lung function in cystic fibrosis sufferers [Scott-Thomas et al., BMC Pulm. Med., 2010, 10, 56]. Currently the detection of 2-AA involves laboratory based instrumentation such as mass spectrometry and a hand-held point-of-care type breath device would be ideal in providing real-time results within seconds to accelerate patient care decision-making processes. To this end, we demonstrate proof-of-concept that the chemical marker 2-AA, indicative of Pseudomonas aeruginosa infection, can be measured using electrochemical based sensing strategies. A range of commercially available electrode substrates are explored demonstrating for the first time that 2-AA is electrochemically active within aqueous based solutions providing an (electro)analytical signal. Glassy carbon, boron-doped diamond and platinum electrodes have been explored towards the electrochemical oxidation of 2-AA. Electrode fouling is observed requiring pre-treatment in the form of mechanical polishing between voltammetric scans and measurements. To alleviate this, screen-printed graphite electrodes are shown to be a more viable option for implementation into breath sensing devices and overcome the fouling problem since due to their low cost and disposable nature, a new electrode can be used for each measurement. The analytical utility of the platinum, screen-printed and boron-doped diamond electrodes were found to correspond to 6.85, 7.66 and 4.86 mM respectively. The challenges associated with the electrochemical sensing of 2-AA in breath that need to be overcome are discussed. This generic approach where electrochemical based technology is used to provide measurements for chemical markers in exhaled air/breath for medical diagnostics termed electrochemical breathprints (ec-breathprints), has the potential to be developed into a hand-held point-of-care breath diagnostic tool for identifying Pseudomonas aeruginosa infection in exhaled air/breath. PMID:24926967
Metters, Jonathan P; Kampouris, Dimitrios K; Banks, Craig E
The new CoaguChek XS system is designed for use in patient selftesting. It is the successor of the current CoaguChek S system. The detection principle is based on the amperometric measurement of the thrombin activity initiated by starting the coagulation cascade using a human recombinant thromboplastin. This study was performed to assign the International SEnsitivity Index (ISI) to the new test according to the WHO guidelines for thromboplastins and plasmas used to control anticoagulant therapy, and to establish the measuring range of the new system. At four study sites a total of 90 samples of normal donors and 291 samples of warfarin-, phenprocoumon- or acenocoumarol-treated patients were included in the study. The ISI value of the new test was assigned against the human recombinant reference thromboplastin rTF/95 at each site using the samples from stabilized patients in the International Normalized Ratio (INR) range between 1.5 and 4.5 only. The new point-of-care system's measuring range between 0.8 and 8 INR was calibrated against the mean INR of rTF/95 and AD149 using polynomial regression. ISIs were (CV of the slope): Site 1: ISI 0.99 (1.1%); Site 2: ISI 1.02 (2.0%); Site 3: ISI 1.03 (1.1%); Site 4: ISI 1.00 (1.4%). All regression lines calculated from patient-only data pass through the normal donor data points. All CVs of the slopes of the orthogonal regression lines are well below 3%, thus fulfilling the requirements of the WHO guidelines. The mean ISI for the new CoaguChek XS PT Test is 1.01. PMID:17479198
Leichsenring, Ingrid; Plesch, Winfried; Unkrig, Volker; Kitchen, Steve; Kitchen, Dianne P; Maclean, Rhona; Dikkeschei, Bert; van den Besselaar, Anton M H P
Background Rapid diagnostic tests (RDTs) for use at the point-of-care (POC) are likely to become increasingly useful as large-scale control programmes for schistosomiasis get underway. Given the low sensitivity of the reference standard egg count methods in detecting light infections, more sensitive tests will be required to monitor efforts aimed at eliminating schistosomiasis as advocated by the World Health Assembly Resolution 65.21 passed in 2012. Methods A recently developed RDT incorporating Schistosoma mansoni cercarial transformation fluid (SmCTF) for detection of anti-schistosome antibodies in human blood was here evaluated in children (mean age: 7.65 years; age range: 1-12 years) carrying light S. mansoni and S. haematobium infections in a schistosome-endemic area of Zimbabwe by comparison to standard parasitological techniques (i.e. the Kato-Katz faecal smear and urine filtration). Enzyme-linked immunosorbent assays (ELISAs) incorporating S. haematobium antigen preparations were also employed for additional comparison. Results The sensitivity of the SmCTF-RDT compared to standard parasitological methods was 100% while the specificity was 39.5%. It was found that the sera from RDT “false-positive” children showed significantly higher antibody titres in IgM-cercarial antigen preparation (CAP) and IgM-soluble egg antigen (SEA) ELISA assays than children identified by parasitology as “true-negatives”. Conclusions Although further evaluations are necessary using more accurate reference standard tests, these results indicate that the RDT could be a useful tool for the rapid prevalence-mapping of both S. mansoni and S. haematobium in schistosome-endemic areas. It is affordable, user-friendly and allows for diagnosis of both schistosome species at the POC.
A device for measuring human breath ammonia was developed based on a single use, disposable, inkjet printed ammonia sensor fabricated using polyaniline nanoparticles. The device was optimized for sampling ammonia in human breath samples by addressing issues such as variations in breath sample volume, flow rate, sources of oral ammonia, temperature and humidity. The resulting system was capable of measuring ammonia in breath from 40 to 2993 ppbv (r(2 )= 0.99, n = 3) as correlated with photoacoustic laser spectroscopy and correlation in normal human breath samples yielded a slope of 0.93 and a Pearson correlation coefficient of 0.9705 (p < 0.05, n = 11). Measurement of ammonia in the breath of patients with end-stage kidney disease demonstrated its significant reduction following dialysis, while also correlating well with blood urea nitrogen (BUN) (r = 0.61, p < 0.01, n = 96). Excellent intraindividual correlations were demonstrated between breath ammonia and BUN (0.86 to 0.96), which demonstrates the possibility of using low cost point of care breath ammonia systems as a noninvasive means of monitoring kidney dysfunction and treatment. PMID:24299143
Hibbard, Troy; Crowley, Karl; Kelly, Frank; Ward, Frank; Holian, John; Watson, Alan; Killard, Anthony J
Early diagnosis of tuberculosis can dramatically reduce both its transmission and the associated death rate. The extremely slow growth rate of the causative pathogen, Mycobacterium tuberculosis (Mtb), however, makes this challenging at the point of care, particularly in resource-limited settings. Here we report the use of BlaC (an enzyme naturally expressed/secreted by tubercle bacilli) as a marker and the design of BlaC-specific fluorogenic substrates as probes for Mtb detection. These probes showed an enhancement by 100-200 times in fluorescence emission on BlaC activation and a greater than 1,000-fold selectivity for BlaC over TEM-1 ?-lactamase, an important factor in reducing false-positive diagnoses. Insight into the BlaC specificity was revealed by successful co-crystallization of the probe/enzyme mutant complex. A refined green fluorescent probe (CDG-OMe) enabled the successful detection of live pathogen in less than ten minutes, even in unprocessed human sputum. This system offers the opportunity for the rapid, accurate detection of very low numbers of Mtb for the clinical diagnosis of tuberculosis in sputum and other specimens.
Xie, Hexin; Mire, Joseph; Kong, Ying; Chang, Mihee; Hassounah, Hany A.; Thornton, Chris N.; Sacchettini, James C.; Cirillo, Jeffrey D.; Rao, Jianghong
An evaluation was commissioned to generate evidence on the impact of PIMA point-of-care CD4+ count machines in maternal and new-born child health settings in Zimbabwe; document best practices, lessons learned, challenges, and recommendations related to scale up of this new technology. A mixed methodology approach that included 31 in-depth interviews with stakeholders involved in procurement, distribution, and use of the POC machines was employed. Additionally, data was also abstracted from 207 patient records from 35 sites with the PIMA POC CD4+ count machines and 10 other comparative sites without the machine. A clearer training strategy was found to be necessary. The average time taken to initiate clients on antiretroviral treatment (ART) was substantially less, 15 days (IQR-1-149) for sites with a PIMA POC machine as compared to 32.7 days (IQR-1-192) at sites with no PIMA POC machine. There was general satisfaction because of the presence of the PIMA POC CD4+ count machine at sites that also initiated ART.
Mtapuri-Zinyowera, Sekesai; Chiyaka, Edward T.; Mushayi, Wellington; Musuka, Godfrey; Naluyinda-Kitabire, Florence; Mushavi, Angella; Chikwasha, Vasco
Background The development of genotyping and genetic sequencing techniques and their evolution towards low costs and quick turnaround have encouraged a wide range of applications. One of the most promising applications is pharmacogenomics, where genetic profiles are used to predict the most suitable drugs and drug dosages for the individual patient. This approach aims to ensure appropriate medical treatment and avoid, or properly manage, undesired side effects. Results We developed the Medicine Safety Code (MSC) service, a novel pharmacogenomics decision support system, to provide physicians and patients with the ability to represent pharmacogenomic data in computable form and to provide pharmacogenomic guidance at the point-of-care. Pharmacogenomic data of individual patients are encoded as Quick Response (QR) codes and can be decoded and interpreted with common mobile devices without requiring a centralized repository for storing genetic patient data. In this paper, we present the first fully functional release of this system and describe its architecture, which utilizes Web Ontology Language 2 (OWL 2) ontologies to formalize pharmacogenomic knowledge and to provide clinical decision support functionalities. Conclusions The MSC system provides a novel approach for enabling the implementation of personalized medicine in clinical routine.
Minarro-Gimenez, Jose Antonio; Blagec, Kathrin; Boyce, Richard D.; Adlassnig, Klaus-Peter; Samwald, Matthias
Purpose. Monitoring patients' international normalized ratio (INR) within a family medicine setting can be challenging. Novel methods of doing this effectively and in a timely manner are important for patient care. The purpose of this study was to determine the effectiveness of a pharmacist-led point-of-care (POC) INR clinic. Methods. At a community-based academic Family Health Team in Toronto, Canada, charts of patients with atrial fibrillation managed by a pharmacist with usual care (bloodtesting at lab and pharmacist follow up of INR by phone) from February 2008 to April 2008 were compared with charts of patients attending a weekly POC INR clinic from February 2010 to April 2010. Time in therapeutic range (TTR) was measured for both groups. Results. 119 patient charts were reviewed and 114 had TTR calculated. After excluding patients with planned inconsistent Coumadin use (20), such as initiating Coumadin treatment or stopping for a surgical procedure, the mean TTR increased from 64.41% to 77.09% with the implementation of the POC clinic. This was a statistically significant difference of 12.68% (CI: 1.18, 24.18; P = 0.03). Conclusion. A pharmacist-led POC-INR clinic improves control of anticoagulation therapy in patients receiving warfarin and should be considered for implementation in other family medicine settings.
Rossiter, Jennifer; Soor, Gursharan; Aliarzadeh, Babak; Lake, Jennifer
A picogram-sensitive optical microfluidic biosensor using an integrated polycarbazole photodiode is developed. The photodetector is mainly composed of the blend heterojunction of poly [N-9'-heptadecanyl-2,7-carbazole-alt-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (PCDTBT) and [6,6]-phenyl C71-butyric acid methyl ester (PC70BM) and the poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) as the hole transport layer. Analyte detection is accomplished via a chemiluminescent immunoassay performed in a poly(dimethylsiloxane)-gold-glass hybrid microchip, on which antibodies were immobilized and chemiluminescent horseradish peroxidase-luminol-peroxide reactions were generated. Enhanced sensor response to the chemiluminescent light is achieved by optimizing the thickness of PCDTBT:??PC70BM and PEDOT:PSS. Using the optimized polycarbazole photodiode for detecting the human thyroid-stimulating hormone as the model target, the integrated biosensor demonstrates an excellent linearity in the range of 0.03 to 10??ng/ml with an analytical sensitivity of 68??pg/ml. The sensor response shows high specificity and reproducibility. Hormone detection in clinical samples is further demonstrated and compared with a commercial enzyme-linked immunosorbent assay. The integrated device reported here has potential to detect other hormonal compounds or protein targets. Moreover, the presented concept enables the development of miniaturized, low-cost but highly sensitive optical microfluidic biosensors based on integrated polymer photodetectors with high potential for point-of-care diagnostics. PMID:24002194
Pires, Nuno Miguel Matos; Dong, Tao; Hanke, Ulrik; Hoivik, Nils
Effective pathogen detection is necessary for treatment of infectious diseases. Point of care (POC) devices have tremendously improved the global human heath. However, design criteria for sample processing POC devices for pathogen detection in limited infrastructure are challenging and can make a significant contribution to global health by providing rapid and sensitive detection of bacteria in food, water, and patient samples. In this paper, we demonstrate a novel portable POC diagnostic device that is simple to assemble for genetic detection of bacterial pathogens by isothermal DNA amplification. The device is fabricated with very low production cost, using simple methods and easy-to-access materials on a flexible ribbon polyethylene substrate. We showed that the device is capable of detection of 30 CFU mL(-1) of E. coli and 200 CFU mL(-1) of S. aureus in less than 1 hour. Through numerical simulations, we estimated that the device can be extended to high-throughput detection simultaneously performing a minimum of 36 analyses. This robust and sensitive detection device can be assembled and operated by non-specialist personnel, particularly for multiple bacterial pathogen detections in low-resource settings. PMID:24300967
Safavieh, Mohammadali; Ahmed, Minhaz Uddin; Sokullu, Esen; Ng, Andy; Braescu, Liliana; Zourob, Mohammed
This paper presents the development of an easy-to-handle and disposable clinical diagnostic lab-on-a-chip using fully integrated plastic microfluidic components, which has the sampling/identifying capability to make fast and reliable measurements of metabolic parameters from human whole blood. A smart and functional lab-on-a-chip cartridge, which incorporates a full on-chip auto-calibration function for in the field applications, has been developed, and then fully characterized using a portable analyzer (3 (1/4)''x 5''x 1'') with multi-analyte detection capability. In addition, several new approaches in realizing smart and functional lab-on-a-chips on polymer have been adopted, which include the pinch valve for automatic fluidic sealing, a by-pass channel as the sampling indicator, and a robust connector design for long analyzer lifetimes. Metabolic parameters such as glucose, lactate, and partial oxygen from human whole blood have been successfully measured using the functional polymer lab-on-a-chips and the portable analyzer developed in this work. PMID:19023474
Do, Jaephil; Lee, Sehwan; Han, Jungyup; Kai, Junhai; Hong, Chien-Chong; Gao, Chuan; Nevin, Joseph H; Beaucage, Gregory; Ahn, Chong H
In this work, electrochemiluminescence (ECL) immunoassay was introduced into the recently proposed microfluidic paper-based analytical device (?PADs) based on directly screen-printed electrodes on paper for the very first time. The screen-printed paper-electrodes will be more important for further development of this paper-based ECL device in simple, low-cost and disposable application than commercialized ones. To further perform high-performance, high-throughput, simple and
Lei Ge; Jixian Yan; Xianrang Song; Mei Yan; Shenguang Ge; Jinghua Yu
The rapid troponin T assay CARDIAC T Quantitative was recalibrated using Elecsys Troponin T 3rd Generation as a new reference method. This paper presents the method comparisons at six centres using the new reference method. Method comparison between CARDIAC T Quantitative versus Elecsys Troponin T 3rd Generation were performed using 319 samples from patients with acute coronary syndromes. The quality
Paul O Collinson; Bo Jørgensen; Christer Sylvén; Markus Haass; Frank Chwallek; Hugo A Katus; Margit Müller-Bardorff; Ulla Derhaschnig; Michael M Hirschl; Rainer Zerback
Myocardial infarction (MI) is the main cause of death all over the world. Biomarkers of cardiac necrosis are of great importance\\u000a in the diagnosis of MI. The aim of this study was to determine probable changes of creatine kinase MB isoform (CK-MB) levels\\u000a in saliva of patients with acute MI. A case–control study was carried out on 30 patients with
Iraj Mirzaii-Dizgah; Seyed Fakhreddin Hejazi; Esmail Riahi; Mohammad Mohsen Salehi
Abstract The application of emerging nanotechnology to the practice of medicine represents a frontier of nanomedicine. Nanomedicine has been defined as a science which emphasizes the use of nanoscale tools in conjunction with background knowledge of the human body for medical diagnosis and treatment. Application of nanomedicine in EM may give EM providers the opportunity to diagnose and treat life-threatening diseases in a shorter period of time. These applications include diagnostic utilities, preventive medicine, targeted pharmacotherapy, and tissue regeneration.
Background Monitoring of HIV viral load in patients on combination antiretroviral therapy (ART) is not generally available in resource-limited settings. We examined the cost-effectiveness of qualitative point-of-care viral load tests (POC-VL) in sub-Saharan Africa. Design Mathematical model based on longitudinal data from the Gugulethu and Khayelitsha township ART programmes in Cape Town, South Africa. Methods Cohorts of patients on ART monitored by POC-VL, CD4 cell count or clinically were simulated. Scenario A considered the more accurate detection of treatment failure with POC-VL only, Scenario B also considered the effect on HIV transmission. Scenario C further assumed that the risk of virologic failure is halved with POC-VL due to improved adherence. We estimated the change in costs per quality-adjusted life-year gained (incremental cost-effectiveness ratios, ICER) of POC-VL compared to CD4 and clinical monitoring. Results POC-VL tests with detection limits <1000 copies/ml increased costs due to unnecessary switches to second-line ART, without improving survival. Assuming POC-VL unit costs between US$5–US$20 and detection limits between 1000 and 10000 copies/ml, the ICER of POC-VL was US$4010–US$9230 compared to clinical and US$5960–US$25540 compared to CD4 monitoring. In Scenario B the corresponding ICERs were US$2450–US$5830 and US$2230–US$10380. In Scenario C the ICER ranged between US$960–US$2500 compared to clinical monitoring and between cost-saving and US$2460 compared to CD4 monitoring. Conclusions The cost-effectiveness of POC-VL for monitoring ART is improved by a higher detection limit, by taking the reduction in new HIV infections into account and when assuming that failure of first-line ART is reduced due to targeted adherence counselling.
ESTILL, Janne; EGGER, Matthias; BLASER, Nello; VIZCAYA, Luisa SALAZAR; GARONE, Daniela; WOOD, Robin; CAMPBELL, Jennifer; HALLETT, Timothy B.; KEISER, Olivia
Surface Plasmon Resonance (SPR) is the base for some of the most sensitive label free optical fiber biosensors. However, most solutions presented to date require the use of fragile fiber optic structure such as adiabatic tapers or side polished fibers. On the other hand, long-period fiber gratings (LPG) present themselves as an interesting solution to attain an evanescent wave refractive index sensor platform while preserving the optical fiber integrity. The combination of these two approaches constitute a powerful platform that can potentially reach the highest sensitivities as it was recently demonstrated by detailed theoretical study [1, 2]. In this work, a LPG-SPR platform is explored in different configurations (metal coating between two LPG - symmetric and asymmetric) operating in the telecom band (around 1550 nm). For this purpose LPGs with period of 396 ?m are combined with tailor made metallic thin films. In particular, the sensing regions were coated with 2 nm of chromium to improve the adhesion to the fiber and 16 nm of gold followed by a 100 nm thick layer of TiO2 dielectric material strategically chosen to attain plasmon resonance in the desired wavelength range. The obtained refractometric platforms were then validated as a biosensor. For this purpose the detection of thrombin using an aptamer based probe was used as a model system for protein detection. The surface of the sensing fibers were cleaned with isopropanol and dried with N2 and then the aminated thrombin aptamer (5'-[NH2]- GGTTGGTGTGGTTGG-3') was immobilized by physisorption using Poly-L-Lysine (PLL) as cationic polymer. Preliminary results indicate the viability of the LPFG-SPR-APTAMER as a flexible platforms point of care diagnostic biosensors.
Coelho, L.; Queirós, R. B.; Santos, J. L.; Martins, M. Cristina L.; Viegas, D.; Jorge, P. A. S.
This descriptive study replicates and extends previous research on advanced practice RNs and the (1) reference resources available to them at the point of care, (2) resources they use to inform their clinical practice, and (3) resources they are accessing from handheld electronic devices such as PDAs, smartphones, and tablet computers during practice. These elements formed the purpose of the current study. A sample of advanced practice RNs from Texas Public Health Region 11 was surveyed. Available resources were current journals appropriate to setting and current clinical guidelines. These advanced practice RNs "always or frequently" based their professional practice on personal experience of caring for patients/clients over time, information learned in college/university, and information learned about each patient/client as an individual. Responses for Hispanic respondents as well as electronic device users were similar. Content and features accessed daily by handheld computer devices were reference materials, e-mail, address/phonebook, Internet access other than e-mail, calendar/date book, alarm/reminder, calculator, and memo pad. Software installed on handheld devices and used daily included drug references, medical text/reference book, medical math/formula calculator, practice guidelines, and language translator/dictionary. Respondents who did not report using handheld devices at work were older, had more years in advanced practice nursing, and were more likely to work in a hospital, birthing center, or institution such as a prison, school, or military facility. There was no difference in resource or electronic device use by Hispanic advanced practice RNs. Electronic resources for practice are growing and being used by advanced practice RNs. Consideration should be given to incorporating evaluation and implementation of electronic clinical resources into advanced practice RN educational programs. Future research should include greater detail about the origin of information used in practice. Patient responses to the use of electronic handheld devices in clinical settings needs illuminating. PMID:24226042
Bischoff, Whitney Rogers; Hinojosa, Rogelio H
We investigated the accuracy of i-STAT(®) (Abbott Point of Care Inc., Princeton, NJ, USA) haemoglobin (Hb) measurement in surgical patients with an estimated blood loss of ?25% of total blood volume. Blood tests for i-STAT(®) Hb, laboratory Hb (Sysmex XE-2100(™), Sysmex Corporation, Kobe, Japan) and total plasma proteins were obtained at the start of surgery (T=0) and when an estimated 25% total blood volume loss had occurred (T=1). Thirty-one patients were recruited. The coefficient of variation of the paired i-STAT(®) Hb estimates was 2.8% and 2.9% at T=0 and T=1, respectively. The mean difference between i-STAT(®) and laboratory Hb was -7.6 g/l (standard deviation 6.5) at T=0 and -5.1 g/l (standard deviation 12) at T=1. The mean total plasma protein difference (total plasma protein T=0 minus T=1) was 13.6 g/l (95% confidence interval 10.2 to 17.0). There was poor correlation between total plasma protein and bias in i-STAT(®) measurements. The i-STAT(®) Hb had an acceptable coefficient of variation, but the Hb levels were lower than those estimated by the laboratory. The standard deviation of i-STAT(®) Hb was greater after ?25% estimated total blood volume loss. Clinicians should not use the i-STAT(®) Hb in isolation for clinical decision-making when considering blood transfusion in a situation of 25% or greater blood loss. PMID:24967765
Ng, Wl; Short, Tg; Gunn, Kn; Fuge, Gs; Slon, B
The recently introduced Xpert MTB/RIF assay (Xpert) has point-of-care potential, but its capacity for biohazard containment remained to be studied. We compared the bioaerosols generated by the Xpert assay to acid-fast bacillus (AFB) microscope slide smear preparation. The Xpert assay sample treatment reagent (SR) was also studied for its sterilizing capacity, stability, and effect on assay sensitivity after prolonged treatment. During the preparation of AFB smears, sputum samples spiked with Mycobacterium bovis BCG at 5 × 108 CFU/ml produced 16 and 325 CFU/m3 air measured with an Andersen impactor or BioSampler, respectively. In contrast, neither the sample preparation steps for the Xpert assay nor its automated processing produced any culturable bioaerosols. In testing of SR sterilizing capacity, clinical sputum samples from strongly smear-positive tuberculosis patients treated with SR at a 2:1 ratio eliminated Mycobacterium tuberculosis growth in all but 1/39 or 3/45 samples cultured on solid or liquid medium, respectively. These few unsterilized samples had a mean 13.1-day delay in the time to positive culture. SR treatment at a 3:1 ratio eliminated growth in all samples. SR retained a greater than 6-log-unit killing capacity despite storage at temperatures spanning 4 to 45°C for at least 3 months. The effect of prolonged SR sample treatment was also studied. Spiked sputum samples could be incubated in SR for up to 3 days without affecting Xpert sensitivity for M. tuberculosis detection and up to 8 h without affecting specificity for rifampin resistance detection. These results suggest that benchtop use of the Xpert MTB/RIF assay limits infection risk to the user.
Banada, Padmapriya P.; Sivasubramani, Satheesh K.; Blakemore, Robert; Boehme, Catharina; Perkins, Mark D.; Fennelly, Kevin; Alland, David
The recently introduced Xpert MTB/RIF assay (Xpert) has point-of-care potential, but its capacity for biohazard containment remained to be studied. We compared the bioaerosols generated by the Xpert assay to acid-fast bacillus (AFB) microscope slide smear preparation. The Xpert assay sample treatment reagent (SR) was also studied for its sterilizing capacity, stability, and effect on assay sensitivity after prolonged treatment. During the preparation of AFB smears, sputum samples spiked with Mycobacterium bovis BCG at 5 × 10(8) CFU/ml produced 16 and 325 CFU/m(3) air measured with an Andersen impactor or BioSampler, respectively. In contrast, neither the sample preparation steps for the Xpert assay nor its automated processing produced any culturable bioaerosols. In testing of SR sterilizing capacity, clinical sputum samples from strongly smear-positive tuberculosis patients treated with SR at a 2:1 ratio eliminated Mycobacterium tuberculosis growth in all but 1/39 or 3/45 samples cultured on solid or liquid medium, respectively. These few unsterilized samples had a mean 13.1-day delay in the time to positive culture. SR treatment at a 3:1 ratio eliminated growth in all samples. SR retained a greater than 6-log-unit killing capacity despite storage at temperatures spanning 4 to 45°C for at least 3 months. The effect of prolonged SR sample treatment was also studied. Spiked sputum samples could be incubated in SR for up to 3 days without affecting Xpert sensitivity for M. tuberculosis detection and up to 8 h without affecting specificity for rifampin resistance detection. These results suggest that benchtop use of the Xpert MTB/RIF assay limits infection risk to the user. PMID:20720033
Banada, Padmapriya P; Sivasubramani, Satheesh K; Blakemore, Robert; Boehme, Catharina; Perkins, Mark D; Fennelly, Kevin; Alland, David
Although abnormalities in blood glucose concentrations in avian species are not as common as they are in mammals, the inability to provide point-of-care glucose measurement likely results in underreporting and missed treatment opportunities. A veterinary glucometer that uses different optimization codes for specific groups of animals has been produced. To obtain data for a psittacine bird-specific optimization code, as well as to calculate agreement between the veterinary glucometer, a standard human glucometer, and a laboratory analyzer, blood samples were obtained from 25 Hispaniolan Amazon parrots (Amazona ventralis) in a 2-phase study. In the initial phase, blood samples were obtained from 20 parrots twice at a 2-week interval. For each sample, the packed cell volume was determined, and the blood glucose concentration was measured by the veterinary glucometer. The rest of each sample was placed into a lithium heparin microtainer tube and centrifuged, and plasma was removed and frozen at -30 degrees C. Within 5 days, tubes were thawed, and blood glucose concentrations were measured with a laboratory analyzer. The data from both procedures were used to develop a psittacine bird-specific code. For the second phase of the study, the same procedure was repeated twice at a 2-week interval in 25 birds to determine agreement between the veterinary glucometer, a standard human glucometer, and a laboratory analyzer. Neither glucometer was in good agreement with the laboratory analyzer (veterinary glucometer bias, 9.0; level of agreement, -38.1 to 56.2; standard glucometer bias, 69.4; level of agreement -17.8 to 156.7). Based on these results, the use of handheld glucometers in the diagnostic testing of Hispaniolan Amazon parrots and other psittacine birds cannot be recommended. PMID:23409433
Acierno, Mark J; Schnellbacher, Rodney; Tully, Thomas N
Background Universal HIV pediatric screening offered at postnatal points of care (PPOC) is an entry point for early infant diagnosis (EID). We assessed the parents' acceptability of this approach in Abidjan, Côte d'Ivoire. Methods In this cross-sectional study, trained counselors offered systematic HIV screening to all children aged 6–26 weeks attending PPOC in three community health centers with existing access to HAART during 2008, as well as their parents/caregivers. HIV-testing acceptability was measured for parents and children; rapid HIV tests were used for parents. Both parents' consent was required according to the Ivorian Ethical Committee to perform a HIV test on HIV-exposed children. Free HIV care was offered to those who were diagnosed HIV-infected. Findings We provided 3,013 HIV tests for infants and their 2,986 mothers. While 1,731 mothers (58%) accepted the principle of EID, only 447 infants had formal parental consent 15%; 95% confidence interval (CI): [14%–16%]. Overall, 1,817 mothers (61%) accepted to test for HIV, of whom 81 were HIV-infected (4.5%; 95% CI: [3.5%–5.4%]). Among the 81 HIV-exposed children, 42 (52%) had provided parental consent and were tested: five were HIV-infected (11.9%; 95% CI: [2.1%–21.7%]). Only 46 fathers (2%) came to diagnose their child. Parental acceptance of EID was strongly correlated with prenatal self-reported HIV status: HIV-infected mothers were six times more likely to provide EID parental acceptance than mothers reporting unknown or negative prenatal HIV status (aOR: 5.9; 95% CI: [3.3–10.6], p?=?0.0001). Conclusions Although the principle of EID was moderately accepted by mothers, fathers' acceptance rate remained very low. Routine HIV screening of all infants was inefficient for EID at a community level in Abidjan in 2008. Our results suggest the need of focusing on increasing the PMTCT coverage, involving fathers and tracing children issued from PMTCT programs in low HIV prevalence countries.
Ndondoki, Camille; Brou, Hermann; Timite-Konan, Marguerite; Oga, Maxime; Amani-Bosse, Clarisse; Menan, Herve; Ekouevi, Didier; Leroy, Valeriane
Improvements in the delivery of community-based healthcare are expectedthrough the adoption of PDAs and mobile communication at the point-of-care. The Australian National Health Information Strategy, Health Online, is providing national leadership for approaches to address the quality and availability of information to assist in the planning and delivery of care. One area for potential growth is the availability and capture
Daniel Walsh; Carole Alcock; Lois Burgess; Joan Cooper
ABSTRACT. Context. Prescribing practices for otitis media are not consistent with current evidence-based recommendations. Objective. To determine whether point-of-care evi- dence delivery regarding the use and duration of antibi- otics for otitis media decreases the duration of therapy from 10 days and decreases the frequency of prescrip- tions written. Design. Randomized, controlled trial. Setting. Primary care pediatric clinic affiliated with
Michelle M. Garrison; Mph Frederick P. Rivara; Robert L. Davis
We present the Microfluidic Electrochemical Quantitative Loop-mediated isothermal AMPlification (MEQ-LAMP) platform for rapid, sensitive, and quantitative detection of pathogen genomic DNA at the point of care. DNA amplification is electrochemically monitored in real time within a monolithic microfluidic device, enabling the detection of as few as 16 copies of Salmonella genomic DNA via a single-step process in under an hour.
Hsieh, Kuangwen; Patterson, Adriana S.; Ferguson, B. Scott; Plaxco, Kevin W.
Background The aim of the study was to compare the diagnostic accuracy of point-of-care cardiac ultrasonography performed by a novice examiner against results from a specialist in cardiology with expert skills in echocardiography, with regard to the assessment of six clinically relevant cardiac conditions in a population of ward patients from the Department of Cardiology or the Department of Cardiothoracic Surgery. Methods Cardiac ultrasonography was performed by a novice examiner at the bedside and images were interpreted in a point-of-care context with dichotomous outcomes (yes/no). Six outcome categories were defined: 1) pericardial effusion (?10 mm), 2) left ventricular dilatation (?62 mm), 3) right ventricular dilatation (?42 mm or???left ventricular diameter), 4) left ventricular hypertrophy (?13 mm), 5) left ventricular failure (EF???40%), 6) aortic stenosis (maximum flow velocity ?3 m/s). The examiner was blinded to the patients’ medical history and results from previous echocardiographic examinations. Results from the interpreted point-of-care ultrasonography examination were compared with echocardiographic diagnosis made by a specialist in cardiology. Results A total of 102 medical and surgical patients were included. Assessments were made in six categories totalling 612 assessments. There was agreement between the novice examiner and the specialist in 95.6% of the cases; overall sensitivity was 0.91 and specificity was 0.97. Positive predictive value was 0.92 and negative predictive value was 0.97. Kappa statistics showed good agreement between observers (?=0.88). Conclusions This study showed that a novice examiner was able to detect common and significant heart pathology in six different categories with good accuracy using POC ultrasonography.
Early diagnosis and management of influenza virus infection directly correlates with the effectiveness in disease control. Current molecular influenza virus tests were designed for use in diagnostic testing facilities, where sophisticated equipment and highly trained technicians are available. A longer turnaround time for the centralized testing than when testing near the sample source could delay the initiation of medical intervention, thereby reducing the efficacy of antiviral treatment. The new assay, the SAMBA (simple amplification-based assay) Flu duplex test, is a dipstick-based molecular assay developed to provide a simple, accurate, and cost-effective solution for the diagnosis of influenza A/B viruses intended for near-patient testing. The test presents an alternative format of influenza virus molecular testing that utilizes isothermal amplification and visual detection of nucleic acid on a test strip. The entire test procedure (extraction, amplification, and detection) is integrated into an enclosed semiautomated system. Analytically, the SAMBA Flu duplex test detects 95 and 85 copies of viral genomes for influenza A and B viruses, respectively, with no cross-reactivity observed against other common respiratory pathogens. The clinical performance was established by blind testing of 328 nasal/throat and nasopharyngeal swab specimens from the United Kingdom and Belgium and comparing the results with the quantitative reverse transcription-PCR method routinely used in two public health laboratories. The SAMBA Flu duplex test showed a clinical sensitivity and specificity of 100% and 97.9% for influenza virus A and 100% and 100% for influenza virus B. The test provides a new technology that could facilitate simple and timely identification of influenza virus infection, potentially resulting in more efficient control measures.
Wu, Liang-Ta; Thomas, Isabelle; Curran, Martin D.; Ellis, Joanna S.; Parmar, Surendra; Goel, Neha; Sharma, Pia I.; Allain, Jean-Pierre
The purpose of this article is to explore the response of nurses to a point-of-care e-health system that was implemented in a large private hospital in South Africa, to determine why the nursing staff rejected the implementation of the system. The study examines user responses with reference to a model designed to account for the use and adoption of mobile handheld devices, having adapted the model for an e-health context. In addition to the input features of technological characteristics and individual differences identified in the model, the added features of nursing culture and group differences were found to be influential factors in fuelling the nurses' resistance to the point-of-care system. Nurses perceived a lack of cultural fit between the system and their work. Their commitment to their nursing culture meant that they were not prepared to adapt their processes to integrate the system into their work. The study shows that the model is useful for understanding adoption in an organizational context and also that the additional elements of nursing culture and group differences are important in an e-health context. PMID:21294686
Whittaker, Louise; Van Zyl, Jaco; Soicher, Antony S
We developed a wireless auto-tracking system for tracking clinical intervention such as drug administrations and blood tests at the patient bedside. The system can not only authenticate patients and nurses, but also confirm medications and provide relevant information, depending on the clinical situation and personnel location. We conducted a feasibility experiment and examined whether or not the system could work
Kumiko Ohashi; Sakiko Ota; Lucila Ohno-Machado; Hiroshi Tanaka
Human illnesses caused by food pathogen are cost-generating problem in societies all over the world. The portable, sensitive and cheap devices for rapid detection of these pathogen are in great interest of many research groups. In this paper the description and first results of test of a miniaturized system for detection of common food pathogens by a real-time PCR is
R. Walczak; J. A. Dziuban; J. Koszur; D. D. Bang; J. Ruano-Lopez
Background: C-reactive protein (CRP) is emerging as a potential risk predictor for future cardiovascular diseases (CVD). High sensitivity assays have been developed and applied for clinical purposes. Methods: The fluorescence immunochromatographic assay was employed to detect and quantify CRP in whole blood. It consisted of a fluorescence (FL) antibody detector buffer, a test strip housed in a disposable cartridge, and
Jae Soon Ahn; Sunga Choi; Sang Ho Jang; Hyuk Jae Chang; Jae Hoon Kim; Ki Bong Nahm; Sang Wook Oh; Eui Yul Choi
Background Mortality in hospitalized, febrile patients in Sub-Saharan Africa is high due to HIV-infected, severely immunosuppressed patients with opportunistic co-infection, particularly disseminated tuberculosis (TB) and cryptococcal disease. We sought to determine if a positive lateral flow assay (LFA) result for urine lipoarabinomannan (LAM) and cryptococcal antigenuria was associated with mortality. Methods 351 hospitalized, HIV-positive adults with symptoms consistent with TB and who were able to provide both urine and sputum specimens were prospectively enrolled at Mulago National Referral Hospital in Uganda as part of a prospective accuracy evaluation of the lateral flow Determine TB LAM test. Stored frozen urine was retrospectively tested for cryptococcal antigen (CRAG) using the LFA. We fitted a multinomial logistic regression model to analyze factors associated with death within 2 months after initial presentation. Results The median CD4 of the participants was 57 (IQR: 14–179) cells/µl and 41% (145) were microbiologically confirmed TB cases. LAM LFA was positive in 38% (134), 7% (25) were CRAG positive, and 43% (151) were positive for either test in urine. Overall, 21% (75) died within the first 2 months, and a total of 32% (114) were confirmed dead by 6 months. At 2 months, 30% of LAM or CRAG positive patients were confirmed dead compared to 15.0% of those who were negative. In an adjusted model, LAM or CRAG positive results were associated with an increased risk of death (RRR 2.29, 95% CI: 1.29, 4.05; P?=?0.005). Conclusions In hospitalized HIV-infected patients, LAM or CRAG LFA positivity was associated with subsequent death within 2 months. Further studies are warranted to examine the impact of POC diagnostic ‘test and treat’ approach on patient-centered outcomes.
Manabe, Yukari C.; Nonyane, Bareng A. S.; Nakiyingi, Lydia; Mbabazi, Olive; Lubega, Gloria; Shah, Maunank; Moulton, Lawrence H.; Joloba, Moses; Ellner, Jerrold; Dorman, Susan E.
Detection of Mycobacterium tuberculosis antigens in urine is attractive as a potential means of diagnosing tuberculosis (TB) regardless of the anatomical site of disease. The most promising candidate antigen is the cell wall lipopolysaccharide antigen lipoarabinomannan (LAM), which has been used to develop commercially available enzyme-linked immunosorbent assays. Although highly variable diagnostic accuracy has been observed in different clinical populations, it is now clear that this assay has useful sensitivity for diagnosis of HIV-associated TB in patients with advanced immunodeficiency and low CD4 cell counts. Thus, this assay is particularly useful when selectively used among patients enrolling in antiretroviral treatment services or in HIV-infected patients requiring admission to hospital medical wards. These are the very patients who have the highest mortality risk and who stand to gain the most from rapid diagnosis, permitting immediate initiation of TB treatment. A recently developed low-cost, lateral-flow (urine ‘dip-stick’) format of the assay provides a result within 30 minutes and is potentially a major step forward as it can be used at the point-of-care, making the possibility of immediate diagnosis and treatment a reality. This paper discusses the likely utility of this point-of-care assay and how it might best be used in combination with other diagnostic assays for TB. The many further research studies that are needed on this assay are described. Consideration is particularly given to potential reasons for the variable specificity observed in existing field evaluations of LAM ELISAs. Whether this might be related to the assay itself or to the challenges associated with study design is discussed.
Detection of Mycobacterium tuberculosis antigens in urine is attractive as a potential means of diagnosing tuberculosis (TB) regardless of the anatomical site of disease. The most promising candidate antigen is the cell wall lipopolysaccharide antigen lipoarabinomannan (LAM), which has been used to develop commercially available enzyme-linked immunosorbent assays. Although highly variable diagnostic accuracy has been observed in different clinical populations, it is now clear that this assay has useful sensitivity for diagnosis of HIV-associated TB in patients with advanced immunodeficiency and low CD4 cell counts. Thus, this assay is particularly useful when selectively used among patients enrolling in antiretroviral treatment services or in HIV-infected patients requiring admission to hospital medical wards. These are the very patients who have the highest mortality risk and who stand to gain the most from rapid diagnosis, permitting immediate initiation of TB treatment. A recently developed low-cost, lateral-flow (urine 'dip-stick') format of the assay provides a result within 30 minutes and is potentially a major step forward as it can be used at the point-of-care, making the possibility of immediate diagnosis and treatment a reality. This paper discusses the likely utility of this point-of-care assay and how it might best be used in combination with other diagnostic assays for TB. The many further research studies that are needed on this assay are described. Consideration is particularly given to potential reasons for the variable specificity observed in existing field evaluations of LAM ELISAs. Whether this might be related to the assay itself or to the challenges associated with study design is discussed. PMID:22536883
Lawn, Stephen D
Background Point-of-care electronic medical records (EMRs) are a key tool to manage chronic illness. Several EMRs have been developed for use in treating HIV and tuberculosis, but their applicability to primary care, technical requirements and clinical functionalities are largely unknown. Objectives This study aimed to address the needs of clinicians from resource-limited settings without reliable internet access who are considering adopting an open-source EMR. Study eligibility criteria Open-source point-of-care EMRs suitable for use in areas without reliable internet access. Study appraisal and synthesis methods The authors conducted a comprehensive search of all open-source EMRs suitable for sites without reliable internet access. The authors surveyed clinician users and technical implementers from a single site and technical developers of each software product. The authors evaluated availability, cost and technical requirements. Results The hardware and software for all six systems is easily available, but they vary considerably in proprietary components, installation requirements and customisability. Limitations This study relied solely on self-report from informants who developed and who actively use the included products. Conclusions and implications of key findings Clinical functionalities vary greatly among the systems, and none of the systems yet meet minimum requirements for effective implementation in a primary care resource-limited setting. The safe prescribing of medications is a particular concern with current tools. The dearth of fully functional EMR systems indicates a need for a greater emphasis by global funding agencies to move beyond disease-specific EMR systems and develop a universal open-source health informatics platform.
Bru, Juan; Berger, Christopher A
We have developed a nucleic acid-based assay that is rapid, sensitive, specific, and can be used for the simultaneous detection of 5 common human respiratory pathogens including influenza A, influenza B, parainfluenza type 1 and 3, respiratory syncytial virus, and adenovirus group B, C, and E. Typically, diagnosis on an un-extracted clinical sample can be provided in less than 3 hours, including sample collection, preparation, and processing, as well as data analysis. Such a multiplexed panel would enable rapid broad-spectrum pathogen testing on nasal swabs, and therefore allow implementation of infection control measures, and timely administration of antiviral therapies. This article presents a summary of the assay performance in terms of sensitivity and specificity. Limits of detection are provided for each targeted respiratory pathogen, and result comparisons are performed on clinical samples, our goal being to compare the sensitivity and specificity of the multiplexed assay to the combination of immunofluorescence and shell vial culture currently implemented at the UCDMC hospital. Overall, the use of the multiplexed RT-PCR assay reduced the rate of false negatives by 4% and reduced the rate of false positives by up to 10%. The assay correctly identified 99.3% of the clinical negatives, 97% of adenovirus, 95% of RSV, 92% of influenza B, and 77% of influenza A without any extraction performed on the clinical samples. The data also showed that extraction will be needed for parainfluenza virus, which was only identified correctly 24% of the time on un-extracted samples.