In the last decade, point-of-care tests were developed to provide rapid generation of test results. These tests have increasingly broad applications. In the area of hemostasis, the international normalized ratio, INR point-of-care test (POCT INR), is the main test of this new proposal. This test has great potential benefit in situations where the quick INR results influences clinical decision making, as in acute ischemic stroke, before surgical procedures and during cardiac surgery. The INR POCT has the potential to be used for self-monitoring of oral anticoagulation in patients under anticoagulant therapy. However, the precision and accuracy of INR POCT still need to be enhanced to increase effectiveness and efficiency of the test. Additionally, the RDC / ANVISA Number 302 makes clear that the POCT testing must be supervised by the technical manager of the Clinical Laboratory in the pre-analytical, analytical and post-analytical. In practice, the Clinical Laboratory does not participate in the implementation of POCT testing or release of the results. Clinicians have high expectation with the incorporation of INR POCT in clinical practice, despite the limitations of this method. These professionals are willing to train the patient to perform the test, but are not legally responsible for the quality of it and are not prepared for the maintenance of equipment. The definition of who is in charge for the test must be one to ensure the quality control. PMID:22996982
Dusse, Luci Maria Sant'Ana; Oliveira, Nataly Carvalho; Rios, Danyelle Romana Alves; Marcolino, Milena Soriano
The POCT(point of care testing) is not enough popular as the term in Japan, but many tests are actually performed as POCT. We have developed POCT analyzer to measure WBC and CRP simultaneously from whole blood, and one of its key technologies is Hct correction of CRP concentration from whole blood to plasma. After its launch, the users are discussing some findings, one of what is a transition phase of WBC and CRP found by frequent measurement of both. In case of acute infectious inflammation, the CRP peak follows the WBC peak after 1 or 2 days. Needless to say, this finding makes haste to foresee a remission by both doctor and patient family. Thus, the POCT has a possibility to give additional and/or another advanced medical relevance even if it is alternative. PMID:12491598
Although central laboratory testing has been the norm for the last few decades and point-of-care testing (POCT) is considered an emerging area, physicians were performing POCT long before the existence of central laboratory testing. As medical directors of POCT programs, pathologists need the basic knowledge and skills associated with directing laboratory-based testing programs as well as additional knowledge and skills about testing at the point of care. Although the essential elements of quality testing are the same for laboratory-based and POCT, the enormous variety of settings, technologies, and workers involved present unique challenges. PMID:17556092
Campbell, Sheldon; Howanitz, Peter J
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
Drug testing with the use of point of care testing (POCT) has been widely used in Japan, especially in the field of drug abuse, poisoning, and anticoagulant therapy with warfarin. For evidence-based medicine of POCT, an interesting report was presented by the National Academy of Clinical Biochemistry in the United States as the guideline in 2006. Users of POCT devices should understand all limitations of the devices. This strength/consensus recommendation is strong and the level of evidence is high. In this field, cyan, arsenic, paraquat, organic phosphate, methanol, acetaminophen, barbiturates, benzodiazepines, antidepressants, and some other drugs were detected by POCT devices such as Triage DOA and a detector tube system and others in Japan. The usefulness of the organophosphorus pesticide detection kit in the accident of GYOZA POISONING from china was noteworthy. In the case of toluene intoxication, the detector tube system was useful as a screening test for the gas phase test of a 2-year-old patient's vomit and excreta without any information from his parents. In warfarin treatment, a POCT device was useful for small hospitals and clinics. Although the cost is not covered by the health insurance system in Japan, the emergency centers of hospitals use these POCT devices for clinical decision-making. This is the most important problem. PMID:23427699
For point-of-care-testing (POCT), the French regulation on medical biology states allows a unique situation where a delayed validation of results is possible. This paper proposes guidelines to organize POCT post-analytical phase in agreement with the local regulation and ISO 22870 requirements. In the first part, organization of POCT validation is detailed (since analysis results reading by the physician until validation of results by the medical biologist and their integration into the patient record). In a second part, elements to include in POCT presentation of results are discussed and a model is proposed. PMID:22736708
Penet, S; Vuillaume, I; Nicolas, T; Szymanowicz, A; Houlbert, C; Pernet, P
Background: Point-of-care testing (POCT) can provide rapid test results, but its impact on patient care is not well documented. We investigated the ability of POCT to decrease inpatient and outpatient waiting times for cardiovascular procedures. Methods: We prospectively studied, over a 7-month period, 216 patients requiring diagnostic laboratory test- ing for coagulation (prothrombin time\\/activated partial thromboplastin time) and\\/or renal function
James H. Nichols; Thomas S. Kickler; Karen L. Dyer; Sandra K. Humbertson; Peg C. Cooper; William L. Maughan; Denise G. Oechsle
Point-of-care testing (POCT) has been used for illicit substance screening in several settings, primarily in law enforcement and drug treatment centers. In this study, we evaluate the use of this screening approach in the emergency department (ED) of a tertiary-care, urban medical center. Aliquots of urine specimens were tested simultaneously by a POCT device (OnTrak™) and by a laboratory-based screening
Todd A. Mastrovitch; William G. Bithoney; Vincent A. DeBari; Nina A. Gold
Point-of-care testing (POCT) devices are in-vitro diagnostic devices used near the patient and for the most part distant from the pathology laboratory. By definition they have a large scope of settings and user profiles. POCT optimises care pathways and overcomes geographical barriers but has a high potential for adverse incidents. A successful POCT service needs good clinical governance and a comprehensive quality management system. In New Zealand, Medsafe regulates medical devices including POCT devices in accordance with the Medicines Act 1981. A number of regulations impact on the use of devices but none address analytical and clinical performance. In 2015 PHARMAC will assume responsibility for management of medical devices. We propose a governance framework that optimises patient safety and maximises benefit from this indispensable technology. This is the first of two articles; the second will address point-of-care governance at healthcare provider level. PMID:24157993
Musaad, Samarina M A; Herd, Geoff
Introduction: Coeliac disease is an autoimmune condition resulting from an abnormal reaction to dietary gluten leading to small bowel villous atrophy. International prevalence studies suggest that coeliac disease affects 1% of the adult population. However, despite its high prevalence, large numbers of patients go undiagnosed. One method of increasing detection rates would be to introduce a quick screening test in the form of a finger-prick blood test. Areas covered: There are currently four available point-of-care tests (POCTs) available for use by health professionals. This diagnostic evaluation will review the evidence for the use of POCTs in coeliac disease including Simtomax a novel test for deamidated gliadin peptides and total IgA level. Expert opinion: An accurate POCT has the potential to increase the rates of diagnosis of coeliac disease if used effectively as part of a case finding approach in primary or secondary care. Evidence for the use of Simtomax is currently fairly limited only drawing comparison with laboratory serology rather than the gold standard of histology and it has only been trialled in high-risk populations. However, results to date are encouraging and further research into this area is required. PMID:24059495
Mooney, Peter D; Kurien, Matthew; Sanders, David S
The aim of this validation study was to compare prothrombin time (PT) and activated partial thromboplastin time (APTT) results from a point-of-care testing (POCT) device (Rapidpoint Coag) with those from standard laboratory tests. The subjects were newborn infants needing coagulation screen for any clinical indications within a regional neonatal intensive care unit. The level of agreement between POCT and laboratory measurements of PT and APTT was determined. For PT: the bias was from -7.6 to 12.4 s and precision was 5.0 s. For the detection of prolonged PT at a level of 16 s, the sensitivity was 0.70, specificity was 0.57 and the positive predictive value (PPV) was 0.62. For APTT: the bias was from -39.1 to 23.7 s, and precision was 15.7 s. For the detection of prolonged APTT at a level of 55 s, the sensitivity was 0.80, specificity was 0.95 and the PPV was 0.80. The POCT device tested has limited utility as a cot-side device for screening for a prolongation of the APTT in the newborn but is not sensitive for screening for prolongation of the PT. PMID:16630216
Tan, K; Booth, D; Newell, S J; Dear, P R F; Hughes, C; Richards, M
Efforts to move molecular diagnostic technologies out of a centralised lab setting and closer to the patient have proved problematic. Early diagnosis of disease is often dependent upon detection of trace amounts of a molecular marker in a complex background. This challenging analytical scenario is compounded when testing is done in rapid manner using miniaturized & portable instruments. Metrology will be fundamental to delivering high quality and reliable clinical data with measurable sensitivity & robustness. Quality of the sample, integrity of the analyser, and ease of use together with incorporation of appropriate QC standards and demonstration of "fitness for purpose" will be key challenges.
Point-of-care testing (POCT) in haematology has continued to grow in popularity and uptake throughout the world. The increasing demand to reduce the turnaround time of test results, coupled with rapid improvements in technology, have led to the development of several devices that are designed for use in different clinical settings, with the hope of improving patient care. The most used POCT in haematology is measurement of haemoglobin concentration. Other POCT devices (used primarily in developing countries) for malaria screening and CD4+ T-lymphocytes for quantification of human-immunodeficiency-virus are becoming the cornerstone for the diagnosis and management of these disorders. New devices are also available for red cell indices, white blood cell count and platelets. In this review clinical studies that validate the use of such devices will be discussed, as well as the advantages and disadvantages of POCT in haematology. A disadvantage of POCT is a lack of training, poor standardization in obtaining blood samples and insufficient internal/external quality assessment. As there is every reason to expect that POCT use will increase in all pathology disciplines, including haematology, it is imperative that systems are put in place to oversee these issues. PMID:22765160
Briggs, Carol; Kimber, Simon; Green, Laura
Objective. To investigate the diagnostic accuracy and clinical benefit of point-of-care Troponin T testing (POCT-TnT) in the management of patients with chest pain. Design. Observational, prospective, cross-sectional study with followup. Setting. Three primary health care (PHC) centres using POCT-TnT and four PHC centres not using POCT-TnT in the southeast of Sweden. Patients. All patients ?35 years old, contacting one of the primary health care centres for chest pain, dyspnoea on exertion, unexplained weakness, and/or fatigue with no other probable cause than cardiac, were included. Symptoms should have commenced or worsened during the last seven days. Main Outcome Measures. Emergency referrals, patients with acute myocardial infarctions (AMI), or unstable angina (UA) within 30 days of study enrolment. Results. 25% of the patients from PHC centres with POCT-TnT and 43% from PHC centres without POCT-TnT were emergently referred by the GP (P = 0.011 ). Seven patients (5.5%) from PHC centres with POCT-TnT and six (8.8%) from PHC centres without POCT-TnT were diagnosed as AMI or UA (P = 0.369). Two patients with AMI or UA from PHC centres with POCT-TnT were judged as missed cases in primary health care. Conclusion. The use of POCT-TnT may reduce emergency referrals but probably at the cost of an increased risk to miss patients with AMI or UA.
Nilsson, Staffan; Andersson, Per O.; Borgquist, Lars; Grodzinsky, Ewa; Janzon, Magnus; Kvick, Magnus; Landberg, Eva; Nilsson, Hakan; Karlsson, Jan-Erik
When counselling patients for postexposure prophylaxis after sexual exposure, we may need to inform them that the efficacy may be low, especially if the patient also had risks prior to the 72 hours between exposure and treatment. The use of a point-of-care test, as well as fourth generation HIV tests and HIV RNA in combination, can still miss seroconversion in the 'eclipse' phase of the infection as these tests are not designed to detect the earliest phase of infection. PMID:22174065
Chan, S Y; Wyld, C; Rice, P; Lau, R
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.
Background D-dimer is used widely as a diagnostic aid in low- and moderate-risk patients with suspected venous thromboembolism (VTE). While our laboratory utilizes VIDAS D-dimer analyzer (bioMérieux SA, France), our emergency department (ED) recently procured a D-dimer analyzer AQT90 FLEX (Radiometer Medical ApS, Denmark) for point of care testing (POCT) to facilitate patient management. We aimed to determine whether the time taken to receive D-dimer results using the 2 different analyzers differed significantly and to quantify the limits of agreement between the results of the 2 methods measured on the same patient. Methods Adult patients presenting to the ED and requiring diagnostic workup for suspected VTE were included in this prospective observational study. Patients underwent simultaneous D-dimer measurements using the 2 different analyzers. Results The paired results from 104 patients were analyzed. The median time for the D-dimer results from triage by VIDAS was 258 min (Inter-quartile range [IQR], 173-360) and by POCT was 146 min (IQR, 55-280.5); the median time difference was 101.5 min (IQR, 82-125.5). On an average, POCT D-dimer values were 15% lower on the same sample (limits of agreement, 34-213%). POCT predicted 83% of VIDAS positive results (sensitivity, 83.3% [95% confidence interval (CI), 70.4-91.3%]; specificity, 100% [95% CI, 93.6-100%]). All patients with positive imaging were identified correctly by both methods. Conclusions POCT delivers D-dimer results in significantly shorter turnaround times than pathology services; however, poor bioequivalence between VIDAS and POCT raises the issue of acceptability for use in the ED.
Perveen, Shuhana; Unwin, Danielle
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) for blood hemoglobin and hematocrit (H\\/H) levels provides rapid patient assessment including the need for transfusion. Conductivity-based methods of blood H\\/H determinations can be influenced by plasma protein concentration. To assess this factor, we measured H\\/H levels at varying protein concentrations using two POCT instruments: iSTAT-1 (conductivity method) and Hemocue (optical method). These H\\/H results were compared
Sidney M. Hopfer; Francesca L. Nadeau; Marilyn Sundra; Gregory S. Makowski
Blood sampling for laboratory testing is a major cause of iatrogenic blood loss and anemia in neonatal intensive care unit [NICU] patients. The objective of the study was to assess whether the implementation of a multi-parameter Point of Care Test [POCT] (Roche, Cobas b221) analyzer affected blood loss for central laboratory testing and need for red blood cell transfusion in
Ludo Mahieu; Annick Marien; Jozef De Dooy; Margo Mahieu; Hanne Mahieu; Viviane Van Hoof
Background While point of care testing (PoCT) for general practitioners is becoming increasingly popular, few studies have investigated whether it represents value for money. This study aims to assess the relative cost-effectiveness of PoCT in general practice (GP) compared to usual testing practice through a pathology laboratory. Methods A cost-effectiveness analysis based on a randomized controlled trial with 4,968 patients followed up for 18 months and fifty-three general practices in urban, rural and remote locations across three states in Australia. The incremental costs and health outcomes associated with a clinical strategy of PoCT for INR, HbA1c, lipids, and ACR were compared to those from pathology laboratory testing. Costs were expressed in year 2006 Australian dollars. Non-parametric bootstrapping was used to generate 95% confidence intervals. Results The point estimate of the total direct costs per patient to the health care sector for PoCT was less for ACR than for pathology laboratory testing, but greater for INR, HbA1c and Lipids, although none of these differences was statistically significant. PoCT led to significant cost savings to patients and their families. When uncertainty around the point estimates was taken into account, the incremental cost-effectiveness ratio (ICER) for PoCT was found to be unfavourable for INR, but somewhat favourable for ACR, while substantial uncertainty still surrounds PoCT for HbA1c and Lipids. Conclusions The decision whether to fund PoCT will depend on the price society is willing to pay for achievement of the non-standard intermediate outcome indicator. Trial registration Australian New Zealand Clinical Trial Registry ACTRN12605000272695
Diabetes mellitus is a major global health problem. Pathology testing for hemoglobin A1c (HbA1c), lipids, and urine albumin\\/creatinine ratio (ACR) has an important role in the management of diabetes patients. Each of these markers can be performed by point-of-care testing (POCT). This article focuses on setting analytical goals (quality specifications) for the imprecision, bias, and total allowable error of these
Mark D. S. Shephard
Laboratory medicine is undergoing tremendous change in recent years driven primarily by technology, regulations, reimbursement, and market forces. In this paradigm shift, the laboratory is under tremendous pressure to adapt to new requirements for critical care testing. Indeed, laboratories have entered the information age where chemical data is being extracted from specimens in totally automated fashion. In the past, laboratory data has played a more historical role in the care of critically ill patients, arriving at the bedside too late to be of significant use in the active, ongoing care of the patient. However, today's physicians taking care of critically ill patients now require that laboratory results are made available in real-time and, if possible, at the patient's point-of-care. Many new testing point-of-care testing (POCT) devices have been developed to address this need however often laboratories implement such distributed devices with little or no attention to the information technology requirements. In fact, as little as 10% of point-of-care testing is actually managed by the central laboratory computer hence critically importance results are not found on the patient's electronic medical record. In addition, the billing and management data for point-of-care testing is often handled manually with no plans to interface point-of-care devices to the laboratory billing and management systems. Because of recent improvements of information handling and interface capability, such shortcomings in data management are no longer acceptable. Indeed, the demands for laboratories to utilize information technology are such that those laboratories with no overall plan for data management of critical care testing will probably not survive this market-driven paradigm. We present a discussion of the various approaches to computerization of point-of-care testing including the advantages and the disadvantages of each approach. PMID:11369352
Blick, K E
BACKGROUND: The Laboratory modernisation process in Ireland will include point of care testing (POCT) as one of its central tenets. However, a previous baseline survey showed that POCT was under-resourced particularly with respect to information technology (IT) and staffing. AIMS: An audit was undertaken to see if POCT services had improved since the publication of National Guidelines and if such services were ready for the major changes in laboratory medicine as envisaged by the Health Service Executive. METHODS: The 15 recommendations of the 2007 Guidelines were used as a template for a questionnaire, which was distributed by the Irish External Quality Assessment Scheme. RESULTS: Thirty-nine of a possible 45 acute hospitals replied. Only a quarter of respondent hospitals had POCT committees, however, allocation of staff to POCT had doubled since the first baseline survey. Poor IT infrastructure, the use of unapproved devices, and low levels of adverse incident reporting were still major issues. CONCLUSIONS: Point of care testing remains under-resourced, despite the roll out of such devices throughout the health service including primary care. The present high standards of laboratory medicine may not be maintained if the quality and cost-effectiveness of POCT is not controlled. Adherence to national Guidelines and adequate resourcing is essential to ensure patient safety. PMID:23575628
O'Kelly, R A; Byrne, E; Mulligan, C; Mulready, K J; O'Gorman, P; O'Shea, P; Boran, G
Point-of-care testing (POCT) is one of the fastest growing sectors of laboratory diagnostics. Most tests in routine use are haematology or biochemistry tests that are of low complexity. Microbiology POCT has been constrained by a lack of tests that are both accurate and of low complexity. We describe our experience of the practical issues around using more complex POCT for detection of Group B streptococci (GBS) in swabs from labouring women. We evaluated two tests for their feasibility in POCT: an optical immune assay (Biostar OIA Strep B, Inverness Medical, Princetown, NJ) and a PCR (IDI-Strep B, Cepheid, Sunnyvale, CA), which have been categorised as being of moderate and high complexity, respectively. A total of 12 unqualified midwifery assistants (MA) were trained to undertake testing on the delivery suite. A systematic approach to the introduction and management of POC testing was used. Modelling showed that the probability of test results being available within a clinically useful timescale was high. However, in the clinical setting, we found it impossible to maintain reliable availability of trained testers. Implementation of more complex POC testing is technically feasible, but it is expensive, and may be difficult to achieve in a busy delivery suite. PMID:22663318
Gray, J W; Milner, P J; Edwards, E H; Daniels, J P; Khan, K S
Background To investigate the possible effects of different levels of attributes of a point-of-care test (POCT) on sexually transmitted infection (STI) professionals' decisions regarding an ideal POCT for STI(s). Methods An online survey was designed based on a large-scale in-depth focus discussion study among STI experts and professionals. The last section of the survey “build your own POCT” was designed by employing the discrete choice experiment approach. Practicing clinicians from two venues, STI-related international conference attendees and U.S. STD clinic clinicians were invited to participate in the survey. Conditional logistical regression modeling was used for data analysis. Results Overall, 256 subjects took the online survey with 218 (85%) completing it. Most of the participants were STD clinic clinicians who already used some POCTs in their practice. “The time frame required” was identified as a major barrier that currently made it difficult to use STI POCTs. Chlamydia trachomatis was the organism chosen as the top priority for a new POCT, followed by a test that would diagnose early seroconversion for HIV, and a syphilis POCT. Without regard to organism type selected, sensitivity of 90–99% was always the most important attribute to be considered, followed by a cost of $20. However, when the test platform was prioritized for early HIV seroconversion or syphilis, sensitivity was still ranked as most important, but specificity was rated second most important. Conclusions STI professionals preferred C. trachomatis as the top priority for a new POCT with sensitivity over 90%, low cost, and a very short completion time.
Hogan, M. Terry; Uy, O. Manuel; Jackman, Joany; Jett-Goheen, Mary; Albertie, Ariel; Dangerfield, Derek T.; Neustadt, Celia R.; Wiener, Zachary S.; Rompalo, Anne M.
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
Blood sampling for laboratory testing is a major cause of iatrogenic blood loss and anemia in neonatal intensive care unit [NICU] patients. The objective of the study was to assess whether the implementation of a multi-parameter Point of Care Test [POCT] (Roche, Cobas b221) analyzer affected blood loss for central laboratory testing and need for red blood cell transfusion in our NICU. This was a retrospective observational cohort study in a NICU with comparison of two serial cohorts of 2 years each. Implementation of a multi-parameter POCT decreased central laboratory performed testing for bilirubin (-32% per patient) and electrolytes (-36% per patient). On average, the net blood volume taken per admitted patient for electrolyte testing decreased with 23.7% and 22.2% for bilirubin testing in the second cohort. After implementation of POCT, fewer very low birth weight infants [VLBWI] required blood transfusion (38.9% vs. 50%, p<.05) as the number of transfusion/infants decreased by 48% (1.57 vs. 2.53, p<0.01). The implementation of POCT was cost-efficient for the Belgian national health insurance, cost reduction -8.3% per neonate. We conclude that implementation of a bedside multi-parameter POCT analyzer decreases transfusions among VLBWI by reducing iatrogenic blood loss for central laboratory testing. PMID:22056692
Mahieu, Ludo; Marien, Annick; De Dooy, Jozef; Mahieu, Margo; Mahieu, Hanne; Van Hoof, Viviane
The development of gonococcal point-of-care tests (POCTs) has been challenging due to the relatively monomorphic nature of the Neisseria genus. The BioStar Optical ImmunoAssay (OIA) POCT for diagnosing Neisseria gonorrhoeae infection detects a specific epitope on the L7/L12 ribosomal protein, which reduces cross-reactivity with other neisseriae, and produces a highly specific test. A laboratory-based evaluation of this POCT was performed to determine its analytical sensitivity and specificity. A panel of N. gonorrhoeae (n=158) and non-gonococcal Neisseria (n=62) isolates were examined. The OIA GC POCT positively reacted with 99.4% of N. gonorrhoeae isolates and produced no reaction with 88.7% of non-gonococcal Neisseria isolates. It cross-reacted with six strains of N. meningitidis and one non-speciated Neisseria sp., but failed to produce a positive result with one isolate of N. gonorrhoeae. The OIA GC POCT required a bacterial suspension of ~6.4×10(5) c.f.u. N. gonorrhoeae ml(-1) and ~6.2×10(6) c.f.u. N. meningitidis ml(-1) to produce a reactive result. The OIA POCT detected the majority of N. gonorrhoeae (99.4%) isolates examined. PMID:21835969
Samarawickrama, Amanda; Alexander, Sarah; Ison, Catherine
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
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
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
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 also result in inappropriate testing, increased consultations and poor health outcomes resulting from inaccurate results. Currently there are very few randomised controlled trials (RCTs) in GP that have investigated these aspects of PoCT. Design/Methods The Point of Care Testing in General Practice Trial (PoCT Trial) was an Australian Government funded multi-centre, cluster randomised controlled trial to determine the safety, clinical effectiveness, cost effectiveness and satisfaction of PoCT in a GP setting. The PoCT Trial covered an 18 month period with the intervention consisting of the use of PoCT for seven tests used in the management of patients with diabetes, hyperlipidaemia and patients on anticoagulant therapy. The primary outcome measure was the proportion of patients within target range, a measure of therapeutic control. In addition, the PoCT Trial investigated the safety of PoCT, impact of PoCT on patient compliance to medication, stakeholder satisfaction, cost effectiveness of PoCT versus laboratory testing, and influence of geographic location. Discussion The paper provides an overview of the Trial Design, the rationale for the research methodology chosen and how the Trial was implemented in a GP environment. The evaluation protocol and data collection processes took into account the large number of patients, the broad range of practice types distributed over a large geographic area, and the inclusion of pathology test results from multiple pathology laboratories. The evaluation protocol developed reflects the complexity of the Trial setting, the Trial Design and the approach taken within the funding provided. The PoCT Trial is regarded as a pragmatic RCT, evaluating the effectiveness of implementing PoCT in GP and every effort was made to ensure that, in these circumstances, internal and external validity was maintained. Trial Registration 12612605000272695
Laurence, Caroline; Gialamas, Angela; Yelland, Lisa; Bubner, Tanya; Ryan, Philip; Willson, Kristyn; Glastonbury, Briony; Gill, Janice; Shephard, Mark; Beilby, Justin
Background In Liverpool, injecting drug users (IDUs), men-who-have-sex-with-men (MSM) and UK Africans experience a disproportionate burden of HIV, yet services do not reach out to these groups and late presentations continue. We set out to: increase testing uptake in targeted marginalized groups through a community and genitourinary medicine (GUM)-based point of care testing (POCT) programme; and conduct a process evaluation to examine service provider inputs and document service user perceptions of the programme. Methods Mixed quantitative, qualitative and process evaluation methods were used. Service providers were trained to use fourth generation rapid antibody/antigen HIV tests. Existing outreach services incorporated POCT into routine practice. Clients completed a semi-structured questionnaire and focus group discussions (FGDs) were held with service providers. Results Between September 2009 and June 2010, 953 individuals underwent POCT (GUM: 556 [59%]; community-based sites: 397 [42%]). Participants in the community were more likely to be male (p = 0.028), older (p < 0.001), of UK African origin (p < 0.001) and IDUs (p < 0.001) than participants from the GUM clinic. Seventeen new HIV diagnoses were confirmed (prevalence = 1.8%), 16 of whom were in risk exposure categories (prevalence: 16/517, 3.1%). Questionnaires and FGDs showed that clients and service providers were supportive of POCT, highlighting benefits of reaching out to marginalised communities and incorporating HIV prevention messages. Conclusions Community and GUM clinic-based POCT for HIV was feasible and acceptable to clients and service providers in a low prevalence setting. It successfully reached target groups, many of whom would not have otherwise tested. We recommend POCT be considered among strategies to increase the uptake of HIV testing among groups who are currently underserved.
Physicians taking care of infants in the first days of life are often faced with neonatal jaundice, especially in an era where post-partum discharge occurs earlier and assessment of newborn bilirubinemia status is required prior to discharge. The Canadian Pediatric Society and the American Academy of Pediatrics have developed and published guidelines for the diagnosis and management of hyperbilirubinemia in newborns. Point of care testing refers to any test performed outside of laboratory by clinical personnel and close to the site of patient care. Based on a summary of multiple reports during the last twenty years, we realize that devices which provide a non-invasive transcutaneous bilirubin (TcB) measurement have proven to be very useful as screening tools and provide a valid estimate of the total serum bilirubin level (TSB). Published data suggest that these devices provide measurements within 30-50 micromol/L of the TSB levels and can replace laboratory measurement particularly when TSB levels are less than 260 micromol/L. At the present time, in the literature, evidence is insufficient to abandon neonatal serum bilirubin testing and replace it with TcB. Any measurement, TSB or TcB, has potential for error. However, we have evidence that TcB, can help avoiding potential errors associated with even visual assessment of jaundice and may be useful as screening device to detect significant jaundice and decrease a large number of unnecessary skin punctures. The current manuscript is based on a careful comprehensive literature review concerning neonatal hyperbilirubinemia. We consider that this manuscript will help clinicians and laboratory professionals in the management of neonatal jaundice. PMID:18929553
Carceller-Blanchard, A; Cousineau, J; Delvin, E E
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
Recently a number of glucose dehydrogenase-based point of care (POCT) systems for glucose monitoring were successfully introduced on the market. Icodextrin, a glucose polymer is widely used as an osmotic agent in continuous ambulatory peritoneal dialysis (CAPD). Its metabolites are substrates for glucose dehydrogenase, inducing an analytical error which is gaining importance in the determination of glucose in a hospital environment. Since icodextrin is hydrolysed by amylase in the extracellular fluids, the analytical error in vivo is aggravated by the presence of the smaller oligosaccharides which originate from amylase activity. Clinicians should be warned about the spurious high glucose results which might occur in icodextrin-treated patients. In particular in in conditions associated with increased amylase activities, analytical errors are to be expected in icodextrin-treated patients. Alternative glucose determination methods should be recommended in the latter group of patients. PMID:17323845
Floré, K; Delanghe, J
Background Point-of-care testing is increasingly being used in general practice to assist GPs in their management of patients with chronic disease. However, patient satisfaction and acceptability of point-of-care testing in general practice has not been widely studied. Aim To determine if patients are more satisfied with point-of-care testing than with pathology laboratory testing for three chronic conditions. Design of study As part of a large multicentre, randomised, controlled trial assessing the use of point-of-care testing in Australian general practice, satisfaction was measured for patients having pathology testing performed by point-of-care testing devices or pathology laboratories. Patients in the trial were managed by GPs for diabetes, hyperlipidaemia, and/or anticoagulant therapy. Method Patient satisfaction was measured using level of agreement with a variety of statements at the end of the study with a patient satisfaction questionnaire for both the intervention and control groups. Analysis was performed using a mixed model analysis of variance (ANOVA) with allowance for clustering at the practice level following Box–Cox transformations of the data to achieve normality. Results Overall, intervention patients reported that they were satisfied with point-of-care testing. In comparison with the control group, the intervention group had a higher level of agreement than control patients with statements relating to their satisfaction with the collection process (P<0.001) and confidence in the process (P<0.001). They also viewed point-of-care testing as strengthening their relationship with their GP (P = 0.010) and motivational in terms of better managing their condition (P<0.001). Conclusion The results from this trial support patient satisfaction and acceptability of point-of-care testing in a general practice setting.
Laurence, Caroline O; Gialamas, Angela; Bubner, Tanya; Yelland, Lisa; Willson, Kristyn; Ryan, Phil; Beilby, Justin
HIV counselling and testing has traditionally been performed by highly trained professionals in clinical settings. With HIV rapid testing, a reliable and easy to use diagnostic tool, paraprofessionals can be trained to administer on-site HIV testing in a variety of non-traditional settings, broadening the HIV detection rates. Our objective was to create a robust and sustainable paraprofessional training module to facilitate off-site HIV rapid testing in non-clinical settings. Trainees attended a series of training sessions involving HIV education, rapid test instructions and communication techniques. After these sessions, trainees competently carried out HIV rapid testing in homeless shelters throughout the Los Angeles county. Agencies motivated to expand HIV screening programmes may use trained paraprofessionals to administer a full range of services (recruitment, pretest counselling, test administration, interpretation of results, post-test counselling and documentation) through this training model and enabling more highly trained healthcare providers to focus efforts on patients identified as HIV-positive. PMID:18725556
Knapp, Herschel; Anaya, Henry D; Feld, Jamie E
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
Amebiasis is a major cause of morbidity and mortality in the developing world. A reliable point-of-care test would help to improve diagnosis and early treatment. We evaluated a novel rapid fecal antigen detection test for E. histolytica (E. HISTOLYTICA QUIK CHEK; TechLab, Inc., Blacksburg, VA), in a cohort of children in Bangladesh where amebiasis is endemic. This point-of-care test had a sensitivity of 100% and a specificity of 100% when compared with enzyme-linked immunosorbent assay antigen detection. PMID:22665604
Korpe, Poonum S; Stott, Blake R; Nazib, Forida; Kabir, Mamun; Haque, Rashidul; Herbein, Joel F; Petri, William A
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.
We assessed the acceptability and operational suitability of a rapid point-of-care syphilis test and identified barriers to testing among high-risk groups and healthcare professionals in a sexually transmitted infections clinic in Manaus, Brazil. Use of this test could considerably alleviate the impact of syphilis in hard-to-reach populations in the Amazon region of Brazil.
Benzaken, Adele S.; de Andrade Rodrigues, Enio Jose; Mayaud, Philippe
OBJECTIVE To evaluate and compare the performance of several different methods available for detection of Chlamydia trachomatis (Ct) infection, and to explore possible testing and treatment strategies incorporating point-of-care testing versus laboratory-based tests. DESIGN Prospective trial and decision analysis.
Geoffrey R. Swain; A. McDonald; R. Pfister
Limited access to diagnostic services and the poor performance of current tests result in a failure to detect millions of tuberculosis cases each year. An accurate test that could be used at the point of care to allow faster initiation of treatment would decrease death rates and could reduce disease transmission. Previous attempts to develop such a test have failed,
Peter Daley; Ruth McNerney
Summary Background: Paracetamol and salicylate are com- monly taken in acute overdose. Clinicians have a low threshold for excluding the presence of these two drugs, by ordering laboratory tests in any patient suspected of ingesting an overdose or with an altered mental state. Aim: To test the effectiveness of a new point of care test that qualitatively detects paracetamol and
C. Dale; A. A. M. AULAQI; J. BAKER; R. C. HOBBS; M. E. L. TAN; C. TOVEY; I. A. L. WALKER; J. A. HENRY
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
In this study, electrochemical immunoassay was introduced into the recently proposed microfluidic paper-based analytical device (?PADs). To improve the performance of electrochemical immunoassay on ?PAD for point-of-care testing (POCT), a novel wax-patterned microfluidic paper-based three-dimensional electrochemical device (3D-?PED) was demonstrated based on the multi-walled carbon nanotubes (MWCNTs) modified ?PAD. Using typical HRP-O-Phenylenediamine-H(2)O(2) electrochemical system, a sandwich immunoassay on this 3D-?PED for sensitive diagnosis of two tumor markers simultaneously in real clinical serum samples was developed with a linear range of 0.001-75.0 UmL(-1) for cancer antigen 125 and 0.05-50.0 ngmL(-1) for carcinoembryonic antigen. In addition, this 3D-?PED can be easily integrated and combined with the recently emerging paper electronics to further develop simple, sensitive, low-cost, disposable and portable ?PAD for POCT, public health and environmental monitoring in remote regions, developing or developed countries. PMID:22226410
Wang, Panpan; Ge, Lei; Yan, Mei; Song, Xianrang; Ge, Shenguang; Yu, Jinghua
Aim: An experimental approach to the use of point-of-care testing for cardiac markers in the Emergency Department (ED) of our Institution has been carried out using two devices (SCS, Dade Behring and Triage Cardiac Panel, Biosite Diagnostics) for the measurement of cardiac markers. Results: (1) From the analytical point of view, a fundamental tool for an efficient management of patients
Sara Altinier; Martina Zaninotto; Monica Mion; Paolo Carraro; Stefano Rocco; Franco Tosato; Mario Plebani
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
A currently emerging approach enables more widespread monitoring of health parameters in disease prevention and biomarker monitoring. Miniaturisation provides the means for the production of small, fast and easy-to-operate devices for reduced-cost healthcare testing at the point-of-care (POC) or even for household use. A critical overview is given on the present state and requirements of POC testing, on µTAS elements
Anna J. Tudos; Geert A. J. Besselink; Richard B. M. Schasfoort
Malaria remains a serious disease in the developing world. There is a growing consensus that new diagnostics are needed in low-resource settings. The ideal malaria diagnostic should be able to speciate; measure parasitemia; low-cost, quick, and simple to use; and capable of detecting low-level infections. A promising development are nucleic acid tests (NATs) for the diagnosis of malaria, which are well suited for point-of-care use because of their ability to detect low-level infections and speciate, and because they have high sensitivity and specificity. The greatest barrier to NAT use in the past has been its relatively high cost, and the amount of infrastructure required in the form of equipment, stable power, and reagent storage. This review describes recent developments to decrease the cost and run time, and increase the ease of use of NAT while maintaining their high sensitivity and specificity and low limit of detection at the point-of-care.
Cordray, Michael S.; Richards-Kortum, Rebecca R.
Point-of-care (POC) tests are an important strategy to address the epidemic of sexually transmitted infections (STIs) among both adolescents and young adults. While access to care and confidentiality are major barriers to STI care, POC tests allow the clinician to provide immediate and confidential test results and treatment. In addition, POC test results constitute a “teachable moment”; that is, an opportunity to provide immediate feedback to the patient that may impact his/her risk behaviors. This paper reviews published data and manufacturer’s product literature describing current point-of-care STI tests, including studies of test performance as well as impact on treatment intervals and disease spread. It presents theoretical and proposed pitfalls and solutions of implementing POC tests in clinical settings, non-traditional settings, and home care venues. We reviewed the available STI tests according to the World Health Organization (WHO) criteria for judging POC tests: the “ASSURRED” criteria (Affordable, Sensitive, Specific, User-friendly, Rapid and Robust, Equipment-free, Delivered).
Huppert, Jill; Hesse, Elizabeth; Gaydos, Charlotte A.
BACKGROUND: There is no consensus favoring a particular strategy for evaluating patients with pharyngitis.\\u000a \\u000a \\u000a OBJECTIVE: To compare a clinical decision aid and a rapid office-based point of care (POC) test with routine culture for group A ?-hemolytic\\u000a streptococcus (GAS).\\u000a \\u000a \\u000a \\u000a \\u000a DESIGN: Prospective observational study.\\u000a \\u000a \\u000a \\u000a \\u000a PARTICIPANTS: Among 179 patients enrolled, 150 were eligible and 148 had POC testing and cultures initially performed.
Steven J. Atlas; Steven M. McDermott; Carol Mannone; Michael J. Barry
A low-cost, fully integrated sample-to-answer, quantitative PCR (qPCR) system that can be used for detection of HIV-1 proviral DNA in infants at the point-of-care in resource-limited settings has been developed and tested. The system is based on a novel DNA extraction method, which uses a glass fiber membrane, a disposable assay card that includes on-board reagent storage, provisions for thermal cycling and fluorescence detection, and a battery-operated portable analyzer. The system is capable of automated PCR mix assembly using a novel reagent delivery system and performing qPCR. HIV-1 and internal control targets are detected using two spectrally separated fluorophores, FAM and Quasar 670. In this report, a proof-of-concept of the platform is demonstrated. Initial results with whole blood demonstrate that the test is capable of detecting HIV-1 in blood samples containing greater than 5000 copies of HIV-1. In resource-limited settings, a point-of-care HIV-1 qPCR test would greatly increase the number of test results that reach the infants caregivers, allowing them to pursue anti-retroviral therapy. PMID:23202333
Jangam, Sujit R; Agarwal, Abhishek K; Sur, Kunal; Kelso, David M
Introduction Autoantibodies against mutated and citrullinated vimentin (MCV) represent a novel diagnostic marker for rheumatoid arthritis (RA). Recently, an increased sensitivity for anti-MCV compared to autoantibodies against cyclic citrullinated peptides (anti-CCP2) was shown in cohorts of patients with early RA and established disease. The aim of this study was to develop and evaluate a point of care test (POCT) for detection of anti-MCV antibodies immediately at the first visit or at the bed side. Methods A lateral-flow immunoassay was developed for simultaneous detection of anti-MCV antibodies and rheumatoid factor (RF-IgG) and evaluated in a prospective setting. Analyses were performed from whole blood samples of patients with seropositive RA (n = 108), seronegative RA as well as other rheumatic disorders (n = 122), and healthy blood donors (n = 200) and compared to detection via ELISA. Results Using the POCT, anti-MCV antibodies were detected in 54.6% and RF-IgG in 56.5% of patients with RA. Specificity was 99.1% for anti-MCV antibodies and 91.2% for RF-IgG. Compared to ELISA's results, POCT sensitivity was 69.3% for anti-MCV and 55.6% for RF-IgG, specificity was 99.7% and 97.2%, respectively. Conclusions This POCT for detection of anti-MCV antibodies and RF-IgG provides high specificity for the diagnosis of RA and is useful in clinical practice due to its simplicity and its reliable performance. This test can greatly improve a timely management of RA and may help in screening patients with suspected RA in non-specialized settings prompting early referrals.
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
A new diagnostic testing device is proposed for point of care (POC) applications. It consists of a microfluidic cartridge with a polymer biochip and an instrument for reading the biochip and controlling the microfluidics. This system allows a very easy determination of several parameters e.g. in patients blood automatically. The biochip is made of a thin polymer foil serving as waveguiding element and as carrier for the receptors on the biochip surface. A sensitive TIRF (total internal reflection fluorescence) readout is realised. Optical elements for incoupling and outcoupling of light are integrated into the foil. Beside the TIRF element, the disposable microfluidic cartridge integrates a sample inlet, several reservoirs for reagents, fluidic microchannels and electrochemical micropumps. Sandwich assays for the detection of clinically relevant parameters have been investigated. This hardware configuration forms the basis for a fully automated compact low cost device using cost efficient disposables.
Brandenburg, Albrecht; Curdt, Franzisca; Nestler, Joerg; Otto, Thomas; Wunderlich, Kai; Michel, Dirk
Analyze the effectiveness of mandated point-of-care (POC) blood glucose (BG) meter quality control (QC) testing. All POC BG QC tests were analyzed to evaluate operator and strip/meter error rates and institutional cost. POC BG QC test failure (17/103,580 over 24 months) was low and no meters failed subsequent linearity testing. Examining individual QC measures shows that operator error occurs frequently and total error rate is related to QC familiarity (>50 QC tests/month, 2.4%; <50 QC tests/month, 3.8%, p < .001). Even among the most competent operators, strip/meter error (1.2 ± 0.3%) accounted for 50% of total error. Compared with manufacturer-recommended QC testing, Joint Commission mandated POC BG QC testing during 2008/2009 incurred excess costs of approximately US$127,000. POC BG meter failure within current guidelines is rare and does not justify the cost of daily QC testing. Frequent QC testing can identify operators needing retraining in POC testing. Strip/meter QC errors are common, are not prevented by current QC testing standards, and may contribute to clinical errors. PMID:22812686
Corl, Dawn E; Yin, Tom S; Hoofnagle, Andrew N; Whitney, Joanne D; Hirsch, Irl B; Wisse, Brent E
Analyze the effectiveness of mandated point-of-care (POC) blood glucose (BG) meter quality control (QC) testing. All POC BG QC tests were analyzed to evaluate operator and strip/meter error rates and institutional cost. POC BG QC test failure (17/103,580 over 24 months) was low and no meters failed subsequent linearity testing. Examining individual QC measures shows that operator error occurs frequently and total error rate is related to QC familiarity (>50?QC tests/month, 2.4%; <50?QC tests/month, 3.8%, p<.001). Even among the most competent operators, strip/meter error (1.2 ± 0.3%) accounted for 50% of total error. Compared with manufacturer- recommended QC testing, Joint Commission mandated POC BG QC testing during 2008/2009 incurred excess costs of approximately US$127,000. POC BG meter failure within current guidelines is rare and does not justify the cost of daily QC testing. Frequent QC testing can identify operators needing retraining in POC testing. Strip/meter QC errors are common, are not prevented by current QC testing standards, and may contribute to clinical errors. PMID:22059934
Corl, Dawn E; Yin, Tom S; Hoofnagle, Andrew N; Whitney, Joanne D; Hirsch, Irl B; Wisse, Brent E
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. PMID:20672123
Yang, Hao; Li, Ding; He, Rong; Guo, Qin; Wang, Kan; Zhang, Xueqing; Huang, Peng; Cui, Daxiang
The purpose of this article is to review current principles and criteria for obtaining Clinical Laboratory Improvement Amendments of 1988 (CLIA ’88) waiver, identify existing point-of-care (POC) coagulation and hematology technologies, and analyze regulatory challenges regarding CLIA-waiver for those and future devices. CLIA ’88 documentation requires tests performed by laboratories with a Certificate of Waiver to be so simple that the likelihood of erroneous results by the user is negligible, or poses no unreasonable risk of harm to the patient if performed incorrectly as determined by the Secretary of Health and Human Services. “Simple” means that the test uses unprocessed samples, has a direct read-out of test results, does not have specifications for user training, and includes instructions for confirmatory testing when advisable. Currently the CLIA-waived hematology and coagulation POC devices only test for hemoglobin (Hb), hematocrit (Hct), and prothrombin time/international normalized ratio (PT/INR). The problem with these devices is the lack of multiplexing. POC coagulation and hematology devices face challenges for obtaining a waiver. These challenges include the lack of clinical needs assessment, miniturized assays that correct for interfering substances, and assays simple enough to be combined in a multiplex platform. Several scenarios demonstrate how POC coagulation or hematology devices can improve crisis care. Industry should perform needs assessment on clinicians and emergency responders to determine which analytes to incorporate on multiplex POC coagulation and hematology devices, and produce devices that address confounding factors.
Curtis, Corbin M.; Kost, Gerald J.; Louie, Richard F.; Sonu, Rebecca J.; Ammirati, Erika B.; Sumner, Stephanie
Infectious diseases continue to cause an enormous burden of death and disability in developing countries. Increasing access to appropriate treatment for infectious diseases could have a major impact on disease burden. Some common infections can be managed syndromically without the need for diagnostic tests, but this is not appropriate for many infectious diseases, in which a positive diagnostic test is needed before treatment can be given. Since many people in developing countries do not have access to laboratory services, diagnosis depends on the availability of point of care (POC) tests. Historically there has been little investment in POC tests for diseases that are common in developing countries, but that is now changing. Lack of regulation of diagnostic tests in many countries has resulted in the widespread use of sub-standard POC tests, especially for malaria, making it difficult for manufacturers of reliable POC tests to compete. In recent years increased investment, technological advances, and greater awareness about the importance of reliable diagnostic tests has resulted in rapid progress. Rapid, reliable and affordable POC tests, requiring no equipment and minimal training, are now available for HIV infection, syphilis and malaria, but POC tests for other infections are urgently needed. Many countries do not have established criteria for licensing and introducing new diagnostic tests, and many clinicians in developing countries have become disillusioned with diagnostic tests and prefer to rely on clinical judgment. Continuing advocacy and training in the use of POC tests are needed, and systems for quality control of POC tests need to be developed if they are to achieve their maximum potential. PMID:20670288
Peeling, R W; Mabey, D
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
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
Objectives. Disease surveillance combines data collection and analysis with dissemination of findings to decision makers. The timeliness of these activities affects the ability to implement preventive measures. Influenza surveillance has traditionally been hampered by delays in both data collection and dissemination. Methods. We used statistical process control (SPC) to evaluate the daily percentage of outpatient visits with a positive point-of-care (POC) influenza test in the University of Utah Primary Care Research Network. Results. Retrospectively, POC testing generated an alert in each of 4 seasons (2004-2008, median 16 days before epidemic onset), suggesting that email notification of clinicians would be 9 days earlier than surveillance alerts posted to the Utah Department of Health website. In the 2008-09 season, the algorithm generated a real-time alert 19 days before epidemic onset. Clinicians in 4 intervention clinics received email notification of the alert within 4 days. Compared with clinicians in 6 control clinics, intervention clinicians were 40% more likely to perform rapid testing (P = 0.105) and twice as likely to vaccinate for seasonal influenza (P = 0.104) after notification. Conclusions. Email notification of SPC-generated alerts provided significantly earlier notification of the epidemic onset than traditional surveillance. Clinician preventive behavior was not significantly different in intervention clinics. PMID:23691297
Gren, Lisa H; Porucznik, Christina A; Joy, Elizabeth A; Lyon, Joseph L; Staes, Catherine J; Alder, Stephen C
By 2012, point of care (POC) testing will constitute roughly one third of the $59 billion in vitro diagnostics market. The ability to carry out multiplexed genetic testing and wireless connectivity are emerging as key attributes of future POC devices. In this study, an inexpensive, user-friendly and compact device (termed Gene-Z) is presented for rapid quantitative detection of multiple genetic markers with high sensitivity and specificity. Using a disposable valve-less polymer microfluidic chip containing four arrays of 15 reaction wells each with dehydrated primers for isothermal amplification, the Gene-Z enables simultaneous analysis of four samples, each for multiple genetic markers in parallel, requiring only a single pipetting step per sample for dispensing. To drastically reduce the cost and size of the real-time detector necessary for quantification, loop-mediated isothermal amplification (LAMP) was performed with a high concentration of SYTO-81, a non-inhibiting fluorescent DNA binding dye. The Gene-Z is operated using an iPod Touch, which also receives data and carries out automated analysis and reporting via a WiFi interface. This study presents data pertaining to performance of the device including sensitivity and reproducibility using genomic DNA from Escherichia coli and Staphylococcus aureus. Overall, the Gene-Z represents a significant step toward truly inexpensive and compact tools for POC genetic testing. PMID:22374412
Stedtfeld, Robert D; Tourlousse, Dieter M; Seyrig, Gregoire; Stedtfeld, Tiffany M; Kronlein, Maggie; Price, Scott; Ahmad, Farhan; Gulari, Erdogan; Tiedje, James M; Hashsham, Syed A
Measuring IgE antibodies is useful in the diagnostic workup of allergy and asthma. This study was designed to assess the value of a new point-of-care test (ImmunoCAP Rapid Wheeze-Rhinitis Child [ICR]; Phadia AB, Uppsala, Sweden) in the diagnosis of atopy in children with allergy-like symptoms such as rhinitis, eczema, and recurrent episodes of wheezing. Patients (n = 175; average age, 7.2 years) referred from primary care were consecutively enrolled in two pediatric allergy referral centers in Italy and were assessed during a single visit. The ICR test included egg, milk, house-dust mite, timothy, mugwort, wall pellitory, birch, olive, cat, and dog allergens. ICR results were consistent with 78% of the positive clinical diagnoses. Agreement between negative ICR results and physician's clinical judgment ranged between 92 and 99% for the single allergens and averaged 96% for the complete profile. Overall agreement of ICR versus clinical diagnosis was 93%. A false positive ICR rate of 1% was recorded. ICR was positive for 94% of the patients with at least one positive clinical diagnosis. Based on the agreement between the physician's assessment of the clinical relevance of each allergen and the ICR results, we concluded that ICR could be a useful tool for primary care physicians to rule in or out the clinical relevance of single ICR allergens. PMID:20236576
Sarratud, Teresita; Donnanno, Simona; Terracciano, Luigi; Trimarco, Gemma; Martelli, Alberto; Petersson, Carl Johan; Borres, Magnus P; Fiocchi, Alessandro; Cavagni, Giovanni
OBJECTIVE: The goal of this paper is to identify strategies for connectivity that will optimize point-of-care testing (POCT) organized as small-world networks in disaster settings. METHODS: We evaluated connectivity failures during the 2010 Haiti Earthquake, applied small-world network concepts, and reviewed literature for point-of-care (POC) connectivity systems. RESULTS: Medical teams responding to the Haiti Earthquake faced connectivity failures that affected patient outcomes. Deploying robust wireless connectivity systems can enhance the efficiency of the disaster response by improving health care delivery, medical documentation, logistics, response coordination, communication, and telemedicine. Virtual POC connectivity education and training programs can enhance readiness of disaster responders. CONCLUSIONS: The admirable humanitarian efforts of more than 4000 organizations substantially impacted the lives of earthquake victims in Haiti. However, the lack of connectivity and small-world network strategies, combined with communication failures, during early stages of the relief effort must be addressed for future disaster preparedness. PMID:21547239
Yu, Jimmy N; Brock, Terry Keith; Mecozzi, Daniel M; Tran, Nam K; Kost, Gerald J
Objective The goal of this paper is to identify strategies for connectivity that will optimize point-of-care testing (POCT) organized as small-world networks in disaster settings. Methods We evaluated connectivity failures during the 2010 Haiti Earthquake, applied small-world network concepts, and reviewed literature for point-of-care (POC) connectivity systems. Results Medical teams responding to the Haiti Earthquake faced connectivity failures that affected patient outcomes. Deploying robust wireless connectivity systems can enhance the efficiency of the disaster response by improving health care delivery, medical documentation, logistics, response coordination, communication, and telemedicine. Virtual POC connectivity education and training programs can enhance readiness of disaster responders. Conclusions The admirable humanitarian efforts of more than 4000 organizations substantially impacted the lives of earthquake victims in Haiti. However, the lack of connectivity and small-world network strategies, combined with communication failures, during early stages of the relief effort must be addressed for future disaster preparedness.
Yu, Jimmy N.; Brock, Terry Keith; Mecozzi, Daniel M.; Tran, Nam K.; Kost, Gerald J.
New oral anticoagulants (NOAC) are approved for several indications for prophylaxis and treatment of venous thromboembolism and for prevention of embolism in atrial fibrillation at fixed daily doses without need of laboratory guided dose adjustment. Due to their low molecular weight of about 500 to 600 Dalton and their hydrophilicity free anticoagulant is excreted immediately through glomerular filtration into the urine. Impairment of renal function may increase the plasma concentration of the anticoagulants and lowered creatinine clearance is a declared contraindication. In contrast to the initial aim of development the anticoagulant effect is required to be determined in special clinical situations. Several specific and non-specific assays using plasma samples are currently undergoing standardization. As all NOACs are excreted into the urine, specific assays were developed for this matrix to determine them quantitatively of qualitatively. Urine samples can be easily and repetitively obtained avoiding problems and risks associated with blood sampling. The qualitative assay can be performed as a point of care test (POC) also by the patient by judging the different colours for the absence or presence of the drugs with the naked eye. The test is rapid (results available within 15 min), sensitive, specific and accurate and does not require a purified NOAC as control. The tests may be a tool for clinicians who need to know for treatment decisions if a NOAC is on board or not. As the tests are specific for oral direct thrombin inhibitors and for oral direct factor Xa inhibitors, the indication does not interfere with other qualitative POC test in development using clotting systems. The test may be indicated for patients at acute hospitalization, before surgery or central nervous system puncture anaesthesia, if fibrinolytic therapy is indicated, acute deterioration of renal function, and for control of adherence to therapy.
Commercial flow cytometers are sophisticated analytical instruments extensively used in research and clinical laboratories. However, they do not meet the challenging practical requirements for point-of-care (POC) testing. PARC has demonstrated a new optical detection technique termed `spatially modulated emission' that delivers high signal-to-noise discrimination without precision optics to enable a flow cytometer that can combine high performance, robustness, compactness, low cost, and ease of use. The detection technique has been extensive evaluated with measurements of absolute CD4+ and percentage CD4 counts in human blood. To benchmark our system we performed a direct one-to-one comparison of measurements on the same samples with a commercial instrument (BD FACSCount) and obtained excellent agreement for both absolute CD4 and percentage CD4. We have assembled the first generation of a compact (˜5x3x2 inch), single-parameter, flow cytometer based on the spatial modulation technique which uses a pin photodiode for detection rather than a PMT or APD. Measurements of the sensitivity and dynamic range of the prototype were conducted with 3.8-um ultra-rainbow calibration beads (Spherotech) and yielded a detection limit of ˜1000 MEPE, which meets the needs for a wide range of bio-particle-detection applications.
Kiesel, Peter; Beck, Markus; Johnson, Noble
Background Point-of-care testing (POCT) is increasingly being used in general practice to assist general practitioners (GPs) in their management of patients with diseases. However, low adherence to quality guidelines in terms of split test procedures has been observed among GPs in parts of the Capital Region in Denmark. Computer reminders embedded in GPs electronic medical records (ComRem) may facilitate improved quality control behaviour, but more research is needed to identify what types of reminders work and when. The overall aim of this study is to evaluate the efficacy of ComRem to improve GPs adherence to quality guidelines. This article describes the rationale and methods of the study that constitute this research project. Methods/design The study is conducted as two randomised controlled trials (RCTs) among general practices in two districts of the Capital Region in Denmark. These districts contain a total of 739 GPs in 567 practices with a total of 1.1 million patients allocated to practice lists. In the first RCT (RCT A), ComRem is compared to postal reminder letters. In the second RCT (RCT B), ComRem is compared to usual activities (no reminders) with a crossover approach. In both of these studies, outcomes are measured by the number of split tests received by the laboratory. Conclusions This study will contribute to knowledge on the efficacy of ComRem in primary care. Because the study does not explore GPs' perceptions and experiences with regard to ComRem, we will subsequently conduct a qualitative survey focusing on these aspects. Trial registrations Study A: ClinicalTrials.gov identifier: NCT01152151 Study B: ClinicalTrials.gov identifier: NCT01152177
Monitoring for drug-induced liver injury (DILI) via serial transaminase measurements in patients on potentially hepatotoxic medications (e.g., for HIV and tuberculosis) is routine in resource-rich nations, but often unavailable in resource-limited settings. Towards enabling universal access to affordable point-of-care (POC) screening for DILI, we have performed the first field evaluation of a paper-based, microfluidic fingerstick test for rapid, semi-quantitative, visual measurement of blood alanine aminotransferase (ALT). Our objectives were to assess operational feasibility, inter-operator variability, lot variability, device failure rate, and accuracy, to inform device modification for further field testing. The paper-based ALT test was performed at POC on fingerstick samples from 600 outpatients receiving HIV treatment in Vietnam. Results, read independently by two clinic nurses, were compared with gold-standard automated (Roche Cobas) results from venipuncture samples obtained in parallel. Two device lots were used sequentially. We demonstrated high inter-operator agreement, with 96.3% (95% C.I., 94.3-97.7%) agreement in placing visual results into clinically-defined "bins" (<3x, 3-5x, and >5x upper limit of normal), >90% agreement in validity determination, and intraclass correlation coefficient of 0.89 (95% C.I., 0.87-0.91). Lot variability was observed in % invalids due to hemolysis (21.1% for Lot 1, 1.6% for Lot 2) and correlated with lots of incorporated plasma separation membranes. Invalid rates <1% were observed for all other device controls. Overall bin placement accuracy for the two readers was 84% (84.3%/83.6%). Our findings of extremely high inter-operator agreement for visual reading-obtained in a target clinical environment, as performed by local practitioners-indicate that the device operation and reading process is feasible and reproducible. Bin placement accuracy and lot-to-lot variability data identified specific targets for device optimization and material quality control. This is the first field study performed with a patterned paper-based microfluidic device and opens the door to development of similar assays for other important analytes. PMID:24098705
Pollock, Nira R; McGray, Sarah; Colby, Donn J; Noubary, Farzad; Nguyen, Huyen; Nguyen, The Anh; Khormaee, Sariah; Jain, Sidhartha; Hawkins, Kenneth; Kumar, Shailendra; Rolland, Jason P; Beattie, Patrick D; Chau, Nguyen V; Quang, Vo M; Barfield, Cori; Tietje, Kathy; Steele, Matt; Weigl, Bernhard H
Monitoring for drug-induced liver injury (DILI) via serial transaminase measurements in patients on potentially hepatotoxic medications (e.g., for HIV and tuberculosis) is routine in resource-rich nations, but often unavailable in resource-limited settings. Towards enabling universal access to affordable point-of-care (POC) screening for DILI, we have performed the first field evaluation of a paper-based, microfluidic fingerstick test for rapid, semi-quantitative, visual measurement of blood alanine aminotransferase (ALT). Our objectives were to assess operational feasibility, inter-operator variability, lot variability, device failure rate, and accuracy, to inform device modification for further field testing. The paper-based ALT test was performed at POC on fingerstick samples from 600 outpatients receiving HIV treatment in Vietnam. Results, read independently by two clinic nurses, were compared with gold-standard automated (Roche Cobas) results from venipuncture samples obtained in parallel. Two device lots were used sequentially. We demonstrated high inter-operator agreement, with 96.3% (95% C.I., 94.3–97.7%) agreement in placing visual results into clinically-defined “bins” (<3x, 3–5x, and >5x upper limit of normal), >90% agreement in validity determination, and intraclass correlation coefficient of 0.89 (95% C.I., 0.87–0.91). Lot variability was observed in % invalids due to hemolysis (21.1% for Lot 1, 1.6% for Lot 2) and correlated with lots of incorporated plasma separation membranes. Invalid rates <1% were observed for all other device controls. Overall bin placement accuracy for the two readers was 84% (84.3%/83.6%). Our findings of extremely high inter-operator agreement for visual reading–obtained in a target clinical environment, as performed by local practitioners–indicate that the device operation and reading process is feasible and reproducible. Bin placement accuracy and lot-to-lot variability data identified specific targets for device optimization and material quality control. This is the first field study performed with a patterned paper-based microfluidic device and opens the door to development of similar assays for other important analytes.
Pollock, Nira R.; McGray, Sarah; Colby, Donn J.; Noubary, Farzad; Nguyen, Huyen; Nguyen, The Anh; Khormaee, Sariah; Jain, Sidhartha; Hawkins, Kenneth; Kumar, Shailendra; Rolland, Jason P.; Beattie, Patrick D.; Chau, Nguyen V.; Quang, Vo M.; Barfield, Cori; Tietje, Kathy; Steele, Matt; Weigl, Bernhard H.
Point-of-care testing[POCT] has many advantages and disadvantages. Rapid availability of the results facilitates immediate decision making, which is a most important advantage. However, the results get lost occasionally and solving this problem is essential for the successful use of POCT. We linked a portable blood gas analyzers to the computer network system in our hospital. At the same time we created a new program to automatically save results and create test orders. Thereafter, there has been no loss of results and the results can be checked quickly at any computer display in our hospital. Surveying past results has also become very easy. This rapid sharing and easy survey of results has enhanced the value of POCT by facilitating more immediate clinical decision making and improving the quality of hospital service. In the near future, POCT will have a much greater menu and be used more widely. Many types of echographic studies will be done at bed side as well. Linking POCT to computer network system and automatically saving the results are critical points to providing quality service in hospitals of the new era. PMID:12451670
An MRSA assay requiring neither labeling nor amplification of target DNA has been developed. Sequence specific binding of fragments of bacterial genomic DNA is detected at femtomolar concentrations using electrochemical impedance spectroscopy (EIS). This has been achieved using systematic optimisation of probe chemistry (PNA self-assembled monolayer film on gold electrode), electrode film structure (the size and nature of the chemical spacer) and DNA fragmentation, as these are found to play an important role in assay performance. These sensitivity improvements allow the elimination of the PCR step and DNA labeling and facilitate the development of a simple and rapid point of care test for MRSA. Assay performance is then evaluated and specific direct detection of the MRSA diagnostic mecA gene from genomic DNA, extracted directly from bacteria without further treatment is demonstrated for bacteria spiked into saline (10(6) cells per mL) on gold macrodisc electrodes and into human wound fluid (10(4) cells per mL) on screen printed gold electrodes. The latter detection level is particularly relevant to clinical requirements and point of care testing where the general threshold for considering a wound to be infected is 10(5) cells per mL. By eliminating the PCR step typically employed in nucleic acid assays, using screen printed electrodes and achieving sequence specific discrimination under ambient conditions, the test is extremely simple to design and engineer. In combination with a time to result of a few minutes this means the assay is well placed for use in point of care testing. PMID:24093127
Corrigan, D K; Schulze, H; Henihan, G; Hardie, A; Ciani, I; Giraud, G; Terry, J G; Walton, A J; Pethig, R; Ghazal, P; Crain, J; Campbell, C J; Templeton, K E; Mount, A R; Bachmann, T T
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.
Emergency departments (EDs) are challenged to provide rapid triage and evaluation to make appropriate patient disposition and timely treatment decisions. Cardiac troponin is the preferred biomarker for evaluation of patients with chest pain. The objective of this before-and-after study was to determine the impact of Point-of-Care (POC) troponin testing on turnaround times, door-to-troponin result times, ED length of stay (LOS) in patients with chest pain, and staff satisfaction with POC testing. After POC implementation, the average door-to-troponin result time significantly decreased from 105 to 51 min (p < 0.000). The average LOS decreased from 290 to 255 min; however, the change was not significant (p = 0.082). The majority of nurses (81%) felt that POC testing encouraged communication among patient care team members, and satisfaction was high with 82% of all ED staff members rating their satisfaction as excellent. PMID:23899951
Koehler, Jeanniline; Flarity, Kathleen; Hertner, George; Aker, Judy; Stout, John Patrick; Gifford, Marilyn; Campbell, Bruce
Point of care testing (POCT) is evolving at an ever increasing rate. This article deals mainly with the aspect of POCT for blood glucose and the problems of external quality assessment (EQA) of point of care devices (POCD). At the present time it is only possible to control precision with EQA, independent of the matrix of the test materials (synthetic polymer-base, plasma/serum, or processed whole blood). The German Federal Medical Council guidelines for laboratory performance allow an interlaboratory imprecision of ±16%. The majority of POCD fulfill these requirements. The long-term stability of results—tested by repeated distribution of the same materials over a 12-month period—is excellent, and the performance of POCD under routine condtions is usually excellent in terms of result-comparability. The problems of accuracy in terms of control materials have still to be mastered.
Wood, William Graham
We evaluated a new point-of-care (POC) device for urine drugs of abuse (DOA) screening including appropriate clinical interpretation and potential benefits in a large academic medical center. Two hundred consecutive urine samples were tested using Syva Rapid Test (SRT) and existing laboratory methods (Syva EMIT II). Agreement between methods was acceptable with some considerations. Threshold concentration differences, drug interferences, and
Jane M. Yang; Kent B. Lewandrowski
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 inexpensive ECL immunoassay on ?PAD for point-of-care testing, a wax-patterned three-dimensional (3D) paper-based ECL device was demonstrated for the very first time. In this 3D paper-based ECL device, eight carbon working electrodes including their conductive pads were screen-printed on a piece of square paper and shared the same Ag/AgCl reference and carbon counter electrodes on another piece of square paper after stacking. Using typical tris-(bipyridine)-ruthenium (?) - tri-n-propylamine ECL system, the application test of this 3D paper-based ECL device was performed through the diagnosis of four tumor markers in real clinical serum samples. With the aid of a facile device-holder and a section-switch assembled on the analyzer, eight working electrodes were sequentially placed into the circuit to trigger the ECL reaction in the sweeping range from 0.5 to 1.1 V at room temperature. In addition, this 3D paper-based ECL device can be easily integrated and combined with the recently emerging paper electronics to further develop simple, sensitive, low-cost, disposable and portable ?PAD for point-of-care testing, public health and environmental monitoring in remote regions, developing or developed countries. PMID:22074665
Ge, Lei; Yan, Jixian; Song, Xianrang; Yan, Mei; Ge, Shenguang; Yu, Jinghua
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.
Objective The objective of this study was to evaluate the feasibility, acceptability, and accuracy of having emergency department (ED) patients perform a rapid, point-of-care (POC) self-test for HIV before routine HIV testing. Methods Patients aged 18 to 65 years were recruited to perform a rapid POC HIV oral fluid at The Johns Hopkins ED in conjunction with the standard-of-care HIV POC test. Acceptability and ease of use were assessed by a questionnaire. Results A total of 259 patients were approached for testing, and 249 (96.1%) consented to perform a self POC HIV test. Of patients performing a self-test, 100% had concordant results with those obtained by the health care worker. Four females (1.6%) were newly identified as HIV positive. Median participant age was 41 years, and 58% of patients were female; 83% were African American, and 16% were white. Overall, greater than 90% of patients reported trust of the test results, ease of testing, and willingness to test again. Approximately 35% of patients indicated they would pay up to a maximum price of $30 for testing. Overall, 46.9% of patients preferred self-testing, and 39.5% preferred health care professional testing. Regarding preferred location for testing, 51.0% preferred home self-testing, 39.5% preferred clinic/ED self-testing (P > 0.05), and 9.5% had no preference. Conclusions A significant proportion of patients offered POC testing in the ED agreed to perform a self–HIV test. Patients’ results were concordant with those obtained by the health care worker; 1.6% were HIV positive. The majority of participants believed the veracity of their results. A greater number of patients preferred self-testing.
Nour, Samah; Hsieh, Yu-Hsiang; Rothman, Richard E.; Jett-Goheen, Mary; Langhorne, Ophelia; Wu, Lan; Peterson, Stephen; Gaydos, Charlotte A.
Background We introduce locally-smoothed (LS) median absolute difference (MAD) curves for the evaluation of hospital point-of-care (POC) glucose testing accuracy. Methods Arterial blood samples (613) were obtained from a university hospital blood gas laboratory. Four hospital glucose meter systems (GMS) were tested against the YSI 2300 glucose analyzer for paired reference observations. We made statistical comparisons using conventional methods (e.g., linear regression, mean absolute differences). Results Difference plots with superimposed ISO 15197 tolerance bands showed bias, scatter, heteroscedasticity, and erroneous results well. LS MAD curves readily revealed GMS accuracy patterns. Performance in hypoglycemic and hyperglycemic ranges erratically exceeded the recommended LS MAD error tolerance limit (5 mg/dl). Some systems showed acceptable (within LS MAD tolerance) or nearly acceptable performance in and around a tight glycemic control (TGC) interval of 80-110 mg/dl. Performance patterns varied in this interval, creating potential for discrepant therapeutic decisions. Conclusions Erroneous results demonstrated by ISO 15197-difference plots must be carefully considered. LS MAD curves draw on the unique human ability to recognize patterns quickly and discriminate accuracy visually. Performance standards should incorporate LS MAD curves and the recommended error tolerance limit of 5 mg/dl for hospital bedside glucose testing. Each GMS must be considered individually when assessing overall performance for therapeutic decision making in TGC.
Kost, Gerald J; Tran, Nam K; Abad, Victor J; Louie, Richard F
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
Objective To evaluate the performance of a point?of?care (POC) syphilis test when used in urban Bolivian maternity hospitals. Methods We tested 8892 pregnant women for syphilis using the Abbott Determine Syphilis TP rapid POC test and rapid plasma reagin (RPR) in the laboratory of four large urban maternity hospitals where national statistics reported a syphilis prevalence of at least 3%. Sera were stored and transferred to the national reference laboratory (INLASA) where RPR testing was repeated. When the reference laboratory staff observed a positive RPR result, a Treponema pallidum particle agglutination assay (TPPA) was performed to confirm these findings. We calculated test performance characteristics for the POC test and hospital RPR using RPR performed at the reference laboratory confirmed by TPPA as the reference standard. Participants received treatment during their initial visit based on the POC test results. Results The sensitivity, specificity, negative predictive value and positive predictive values of the POC syphilis test were: 91.8% (95% confidence intervals 88.4% to 94.5%), 98.5% (98.2% to 98.8%), 71.0% (66.6% to 75.2%), and 99.7% (99.5% to 99.8%), respectively. The RPR values were 75.7% (70.8% to 80.2%), 99.0% (98.9% to 99.3%), 76.9% (72.0% to 81.3%), and 99.0% (98.8% to 99.2%), respectively. Conclusion The Abbott Determine Syphilis TP test proved to be more sensitive than routine RPR and had comparable specificity. POC testing may be a simple way to expand syphilis screening to clinics with no laboratory facilities, improve case detection, and facilitate treatment delivery.
Tinajeros, F; Grossman, D; Richmond, K; Steele, M; Garcia, S G; Zegarra, L; Revollo, R
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
POCT12-A3 is a Clinical Laboratory Standards Institute standard for hospitals about hospital glucose meter procedures and performance standards. I have reviewed this standard based on the attributes of an ideal performance standard. POCT12-A3 has tighter limits than its predecessor for 95% of results, the limits widen for 98% of results, and there are no limits for 2% of results. It is hard to fathom that 2% of the results are unspecified and could cause life-threatening results, as glucose meters do not perform this poorly. There should be a specification for unreported results since, by definition, point-of-care-testing assays are time sensitive. POCT12-A3 provides useful advice about the glucose testing procedure but provides evaluation guidance only about analytical performance. Moreover, the recommended protocol to assess meter performance is biased and likely to underestimate the observed performance. The guideline would be improved if its specification were based on an error grid and contained evaluation protocols for user errors. PMID:24124969
Krouwer, Jan S
Background and Purpose—Recent studies suggest that patients who do not respond to aspirin (ASA) therapy may be at increased risk of ischemic vascular events. The availability of simple to use point-of-care (POC) platelet function tests now potentially allows aspirin nonresponsiveness to be identified in routine clinical practice. However, there are very few data on whether the different tests produce consistent
Paul Harrison; Helen Segal; Kevin Blasbery; Charlene Furtado; Louise Silver; Peter M. Rothwell
Objectives: To assess the accuracy of point-of-care (POC) measurements of capillary blood glucose and glycosylated haemoglobin (HbA1c) levels in a remote Aboriginal community with high diabetes prevalence.\\u000aDesign: Cross-sectional study comparing POC capillary glucose and HbA1c results with those from corresponding venous samples measured in a reference laboratory.\\u000aParticipants and setting: 152 residents aged 11–76 years (representing 76% of population
David D Martin; Mark D S Shephard; Hayley Freeman; Max K Bulsara; Timothy W Jones; Elizabeth A Davis; Graeme P Maguire
Hypoglycemia, if recurrent, may have severe consequences on cognitive and psychomotor development of neonates. Therefore, screening for hypoglycemia is a daily routine in every facility taking care of newborn infants. Point-of-care-testing (POCT) devices are interesting for neonatal use, as their handling is easy, measurements can be performed at bedside, demanded blood volume is small and results are readily available. However, such whole blood measurements are challenged by a wide variation of hematocrit in neonates and a spectrum of normal glucose concentration at the lower end of the test range. We conducted a prospective trial to check precision and accuracy of the best suitable POCT device for neonatal use from three leading companies in Europe. Of the three devices tested (Precision Xceed, Abbott; Elite XL, Bayer; Aviva Nano, Roche), Aviva Nano exhibited the best precision. None completely fulfilled the ISO-accuracy-criteria 15197: 2003 or 2011. Aviva Nano fulfilled these criteria in 92% of cases while the others were <87%. Precision Xceed reached the 95% limit of the 2003 ISO-criteria for values ?4.2mmol/L, but not for the higher range (71%). Although validated for adults, new POCT devices need to be specifically evaluated on newborn infants before adopting their routine use in neonatology. PMID:23906797
Stadelmann Diaw, Corinne; Piol, Nicolas; Urfer, Jocelyne; Werner, Dominique; Roth-Kleiner, Matthias
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
BackgroundThe clinical signs of active trachoma are often present in the absence of ocular Chlamydia trachomatis infection in low prevalence and mass treated settings. Treatment decisions are currently based on the prevalence of clinical signs, and this may result in the unnecessary distribution of mass antibiotic treatment. We aimed to evaluate the diagnostic accuracy of a prototype point-of-care (POC) test,
Emma M. Harding-Esch; Martin J. Holland; Jean-François Schémann; Sandra Molina; Isatou Sarr; Aura A. Andreasen; Chrissy h. Roberts; Ansumana Sillah; Boubacar Sarr; Edward F. Harding; Tansy Edwards; Robin L. Bailey; David C. W. Mabey
Despite successes in efforts to integrate HIV testing into routine care in emergency departments, challenges remain. Kiosk-facilitated, directed HIV self-testing offers one novel approach to address logistical challenges. Emergency department patients, 18-64 years, were recruited to evaluate use of tablet-based-kiosks to guide patients to conduct their own point-of-care HIV tests followed by standard-of-care HIV tests by healthcare workers. Both tests were OraQuick Advance tests. Of 955 patients approached, 473 (49.5%) consented; 467 completed the test, and 100% had concordant results with healthcare workers. Median age was 41 years, 59.6% were female, 74.8% were African-American, and 19.6% were White. In all, 99.8% of patients believed the self-test was "definitely" or "probably" correct; 91.7% of patients "trusted their results very much"; 99.8% reported "overall" self-testing was "easy or somewhat easy" to perform. Further, 96.9% indicated they would "probably" or "definitely" test themselves at home were the HIV test available for purchase; 25.9% preferred self-testing versus 34.4% who preferred healthcare professional testing (p?>?0.05). Tablet-based kiosk testing proved to be highly feasible, acceptable, and an accurate method of conducting rapid HIV self-testing in this study; however, rates of engagement were moderate. More research will be required to ascertain barriers to increased engagement for self-testing. PMID:23970610
Gaydos, Charlotte A; Solis, Melissa; Hsieh, Yu-Hsiang; Jett-Goheen, Mary; Nour, Samah; Rothman, Richard E
Thrombelastography® is a monitor of coagulation and fibrinolytic status, with point-of-care applications in managing haemorrhaging patients. Advocates have suggested a possible role in managing obstetric haemorrhage. This study aims to develop a pregnancy-specific thrombelastography-guided transfusion algorithm, which could be integrated into the management of postpartum haemorrhage. In this prospective observational study, 57 healthy, term-parturients provided pre-caesarean whole blood specimens for thrombelastography analyses. Specimens were processed according to a standardised protocol involving simultaneous analyses using three assays: native (non-activated); kaolin-activated; and kaolin and tissue factor-activated (RapidTEG®). For each assay, the following thrombelastography parameters were measured: reaction time (minutes); clot formation kinetics time (minutes); maximum amplitude (mm); and a angle (degree). Subsequent reference values were used to establish assay-specific reference intervals. For all thrombelastography parameters studied, reference values obtained using a non-activated assay differed from the corresponding values obtained using activated assays, and also demonstrated greater inter-sample variability. From the assay-specific reference intervals obtained, it was possible to establish a pregnancy-specific thrombelastography-guided transfusion algorithm. Specific features of this transfusion algorithm included the preferential use of activated assays, the need for duplicates and a recommendation that an initial baseline thrombelastography measurement is established for subsequent serial comparisons. This transfusion algorithm has been developed to assist with assessment of coagulation and fibrinolytic status during postpartum haemorrhage. PMID:23194210
Hill, J S; Devenie, G; Powell, M
Objective Despite successes in efforts to integrate HIV testing into routine care in emergency departments, challenges remain. Kiosk-facilitated, directed HIV self-testing offers one novel approach to address logistical challenges. Methods Emergency department patients, 18–64 years, were recruited to evaluate use of tablet-based-kiosks to guide patients to conduct their own point-of-care HIV tests followed by standard-of-care HIV tests by healthcare workers. Both tests were OraQuick Advance tests. Results Of 955 patients approached, 473 (49.5%) consented; 467 completed the test, and 100% had concordant results with healthcare workers. Median age was 41 years, 59.6% were female, 74.8% were African-American, and 19.6% were White. In all, 99.8% of patients believed the self-test was “definitely” or “probably” correct; 91.7% of patients “trusted their results very much”; 99.8% reported “overall” self-testing was “easy or somewhat easy” to perform. Further, 96.9% indicated they would “probably” or “definitely” test themselves at home were the HIV test available for purchase; 25.9% preferred self-testing versus 34.4% who preferred healthcare professional testing (p > 0.05). Conclusion Tablet-based kiosk testing proved to be highly feasible, acceptable, and an accurate method of conducting rapid HIV self-testing in this study; however, rates of engagement were moderate. More research will be required to ascertain barriers to increased engagement for self-testing.
Gaydos, Charlotte A; Solis, Melissa; Hsieh, Yu-Hsiang; Jett-Goheen, Mary; Nour, Samah; Rothman, Richard E
We evaluated a new point-of-care (POC) device for urine drugs of abuse (DOA) screening including appropriate clinical interpretation and potential benefits in a large academic medical center. Two hundred consecutive urine samples were tested using Syva Rapid Test (SRT) and existing laboratory methods (Syva EMIT II). Agreement between methods was acceptable with some considerations. Threshold concentration differences, drug interferences, and cross-reactivity profiles of the class-specific assays resulted in performance differences between the POC and central laboratory methods. Clinical interpretation of POC results requires an understanding of these issues as well as the limitations of urine testing. While urine-based screening is used in workplace testing and in a variety of clinical applications, quantitative blood measurements of some drugs (e.g. ethanol, acetaminophen, salicylate, +/-tricyclic antidepressants) will remain important in the emergent setting. Performance of the SRT method takes approximately 10 min. Consequently, the major advantage over laboratory methods is rapid turnaround time. At the Massachusetts General Hospital, the most important application is for samples from the emergency department (about 1700/year). Each institution should assess its own needs and capabilities with regard to POC versus laboratory-based testing for DOA. PMID:11369333
Yang, J M; Lewandrowski, K B
Background: The new Low-Range Heparin Manage- ment Test (LHMT), a method for point-of-care testing (POCT) of heparinization, has been designed to func- tion at the low to moderate heparin concentrations typically found in patients undergoing extracorporeal membrane oxygenation (ECMO). In this study, the new method is compared with two POCT methods and a laboratory-based anti-Xa assay. Methods: We obtained 760
Theresa M. Ambrose; Curtis A. Parvin; Eric Mendeloff; Lori Luchtman-Jones
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 measures The primary outcome was antibiotic prescribing at the index consultation. Secondary outcomes were antibiotic prescribing during 28 days’ follow-up, reconsultation, clinical recovery, and patients’ satisfaction and enablement. Interventions General practitioners’ use of C reactive protein point of care testing and training in enhanced communication skills separately and combined, and usual care. Results General practitioners in the C reactive protein test group prescribed antibiotics to 31% of patients compared with 53% in the no test group (P=0.02). General practitioners trained in enhanced communication skills prescribed antibiotics to 27% of patients compared with 54% in the no training group (P<0.01). Both interventions showed a statistically significant effect on antibiotic prescribing at any point during the 28 days’ follow-up. Clinicians in the combined intervention group prescribed antibiotics to 23% of patients (interaction term was non-significant). Patients’ recovery and satisfaction were similar in all study groups. Conclusion Both general practitioners’ use of point of care testing for C reactive protein and training in enhanced communication skills significantly reduced antibiotic prescribing for lower respiratory tract infection without compromising patients’ recovery and satisfaction with care. A combination of the illness and disease focused approaches may be necessary to achieve the greatest reduction in antibiotic prescribing for this common condition in primary care. Trial registration Current Controlled Trials ISRCTN85154857.
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
Objectives To evaluate nine rapid syphilis tests at eight geographically diverse laboratory sites for their performance and operational characteristics. Methods Tests were compared “head to head” using locally assembled panels of 100 archived (50 positive and 50 negative) sera at each site using as reference standards the Treponema pallidum haemagglutination or the T pallidum particle agglutination test. In addition inter?site variation, result stability, test reproducibility and test operational characteristics were assessed. Results All nine tests gave good performance relative to the reference standard with sensitivities ranging from 84.5–97.7% and specificities from 84.5–98%. Result stability was variable if result reading was delayed past the recommended period. All the tests were found to be easy to use, especially the lateral flow tests. Conclusions All the tests evaluated have acceptable performance characteristics and could make an impact on the control of syphilis. Tests that can use whole blood and do not require refrigeration were selected for further evaluation in field settings.
Herring, A J; Ballard, R C; Pope, V; Adegbola, R A; Changalucha, J; Fitzgerald, D W; Hook, E W; Kubanova, A; Mananwatte, S; Pape, J W; Sturm, A W; West, B; Yin, Y P; Peeling, R W
Nonhealing wounds (stalled, healable) challenge affected individuals, wound clinicians, and society. Nonhealing may result despite local factors being corrected. The interplay between tissue degradation, increased inflammatory response, and abundant protease activity is a challenging quandary. A modified Delphi process was utilized to investigate a protease activity test and practice implications. PMID:22610111
Sibbald, R Gary; Snyder, Robert J; Botros, Mariam; Burrows, Cathy; Coutts, Patricia; D'Souza, Lincoln; Kuhnke, Janet; Labrecque, Chantal; Laforet, Karen; Landis, Stephan; LeBlanc, Kimberly; Maida, Vincent; Pearson, Christine; Suitor, Michele; Belley, Richard; Mehta, Sowmil
Dysnatremia may cause life-threatening encephalopathy in marathon runners. Hypernatremia and exercise-associated hyponatremia (EAH) may manifest with mental status changes and, if untreated, progress to coma and death. We reviewed the on-site blood sodium testing and treatment in collapsed runners at the finish-line medical tent at the Boston marathons from 2001 through 2008. Dysnatremia was diagnosed in 429 (32.5%) of 1,319 collapsed runners. Hypernatremia was present in 366 (27.7%) and hyponatremia in 63 (4.8%). Hypernatremic runners unable to drink fluids were treated with intravenous normal (0.9%) saline. Hyponatremic runners with seizures or coma received intravenous hypertonic (3%) saline. Sixteen runners with EAH able to drink a concentrated oral hypertonic solution recovered within 30 minutes. Based on on-site sodium testing, dysnatremic runners were treated with appropriate intravenous fluids according to validated standards of care. Hyponatremic runners able to drink an oral hypertonic solution recovered promptly. PMID:19687309
Siegel, Arthur J; d'Hemecourt, Pierre; Adner, Marvin M; Shirey, Terry; Brown, Jeffrey L; Lewandrowski, Kent B
Background Computer reminders are increasingly being applied in efforts to improve quality and patient safety. However, research is still needed to establish the effectiveness of different kinds of reminders in various settings. This study aimed to evaluate the effectiveness of computer reminders for improving adherence to a quality assessment scheme for point-of-care testing in general practice. Method The study was conducted as a randomized controlled crossover trial among general practices in the Capital Region of Denmark. The intervention consisted of sending computer reminders (ComRem) to practices not adhering to the guideline recommendations of split testing for hemoglobin and glucose. Practices were randomly allocated into two groups. During the first follow-up period, one of the groups received the ComRem intervention together with the general implementation activities (GIA), while the other group only received the GIA. For the second follow-up period, the intervention was switched between the two groups. Outcomes were measured as split test procedure adherence. Results A total of 142 practices were randomly allocated to the early intervention group and 144 practices to the late intervention group (the control group in the first follow-up period). In the first intervention period, the mean number of split tests performed in the group receiving ComRem group increased from 1.22 to 3.76 (out of eight possible tests) while the mean number of split tests increased from 1.11 to 2.35 in the group targeted by GIA only (p = 0.0059). After the crossover, a similar effect of reminders was observed. Furthermore, the developments in outcome measures over time showed a strong effect of computer reminders beyond the intervention periods. Conclusion There was a significant effect of computer reminders on adherence to the quality assessment scheme for point-of-care testing. Thus, computer reminders seem to be useful for supporting the implementation of relatively simple procedures for quality and safety. Trial registration ClinicalTrials.gov: http://NCT01152177
HIV point-of-care tests (POCTs) give occasional false positive results, causing unnecessary patient anxiety. We aimed to elicit whether false- and true-positive POCTs differed visually. Seventeen false- and 17 true-positive serum samples were randomized into pairs, comprising one false- and one true-positive sample. Two independent readers identified each POCT as negative or positive and compared line strength between pairs. Six further readers graded line strength, 0-5, from POCT photographs. All true-positive samples were identified positive and 8/17 false-positive samples negative, on repeat testing of stored sera. Eight out of the 9 remaining false-positive tests were described as having weaker pigment uptake than their paired true-positive POCT. Mean grade of line strength was 4.2 in true- and 0.9 in false-positive samples, on photographic evaluation. These results suggest false-positive POCTs may differ visually from true-positive POCTs. If larger studies confirm these findings, we may be able to alleviate anxiety in low risk patients with faintly positive POCTs awaiting their confirmatory laboratory result, where the possibility of a false-positive result could be emphasized. PMID:23033518
Sacks, R; Omodele-Lucien, A; Whitbread, N; Muir, D; Smith, A
This paper reviews fourteen 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 weren’t intended to be specific for this pandemic influenza strain, the non-specialized skills required and the timeliness of results make these POC tests potentially valuable for clinical and public health use. Pooled sensitivity and specificity for the POC tests studied were 68% and 81%, respectively, but published values were not homogeneous with sensitivities and specificities ranging from 10–88% and 51–100%, respectively. Pooled positive and negative likelihood ratios were 5.94 and 0.42, respectively. These results support current recommendations for use of rapid POC tests when H1N1 is suspected, recognizing that positive results are more reliable than negative results in determining infection, especially when disease prevalence is high.
Babin, Steven M.; Hsieh, Yu-Hsiang; Rothman, Richard E.; Gaydos, Charlotte A.
The superiority of enoxaparin compared with unfractionated heparin in the medical management of patients with non-ST elevation acute coronary syndromes (NSTE ACS) has been demonstrated in clinical trials. Further, enoxaparin has been shown to be safe and effective during PCI, including in combination with glycoprotein IIb/IIIa inhibitors. Whether enoxaparin is superior to unfractionated heparin in patients with NSTE ACS under-going early invasive strategy is currently being tested in a large clinical trial. Data on the use of enoxaparin in patients undergoing primary angioplasty for ST-segment elevation myocardial infarction are limited. Unlike patients who present to the catheterization laboratory after several doses of enoxaparin where in a steady state anticoagulation might have been achieved, patients who present early after administration of a single dose of subcutaneous enoxaparin may not have an adequate level of anticoagulation for PCI. The ability to monitor activity of enoxaparin in such patients using a point-of-care test might be useful. This report describes a patient with ST-segment elevation myocardial infarction who presented for primary angioplasty 75 minutes after administration of subcutaneous enoxaparin. The Rapidpoint Enox test measured 135 seconds and the patient's corresponding serum anti-Xa level was 0.12 IU/mL indicating a suboptimal level of anticoagulation for PCI. Procedural success was attained using additional 0.3-mg/kg intravenous enoxaparin. PMID:12784820
Veerappan, Balaji; Latif, Faisal; Patibandla, Sushmitha; Hennebry, Thomas; Ghani, Mohammed; Saucedo, Jorge; Schechter, Eliot; Sadanandan, Saihari
Objectives To compare the effectiveness and cost-effectiveness of a promising new point-of-care (POC) chlamydia test with traditional nucleic acid amplification testing (NAAT), and to determine the characteristics that would make a POC test most cost-effective. Methods A decision tree was constructed to model chlamydia screening visits to a sexually transmitted disease clinic by a hypothetical cohort of 10 000 women. The model incorporated programmatic screening costs, treatment costs and medical costs averted through prevention of pelvic inflammatory disease (PID) and its sequelae. Parameter values and costs were estimated for each node in the decision tree based on primary data, published data and unpublished health data. Results For the base-case scenario (POC sensitivity 92.9%; 47.5% of women willing to wait 40 min for test results; test cost $33.48), POC was estimated to save US$5050 for each case of PID averted compared with NAAT. One-way sensitivity analyses indicated that POC would dominate NAAT if the POC test cost is
Huang, Wei; Gaydos, Charlotte A; Barnes, Mathilda R; Jett-Goheen, Mary; Blake, Diane R
Background Despite the availability of testing and treatment, bacterial sexually transmissible infections (STIs) continue to occur at endemic levels in many remote Indigenous communities in Australia. New generation molecular point-of-care (POC) tests have high sensitivity, comparable with conventional diagnostic tests, and have the potential to increase the impact of STI screening. Methods: We developed mathematical models of gonorrhoea (Neisseria gonorrhoeae) and chlamydia (Chlamydia trachomatis) transmission in remote Indigenous communities in Australia to evaluate screening and treatment strategies that utilise POC tests. Results: The introduction of POC testing with 95% sensitivity could reduce the prevalence of gonorrhoea and chlamydia from 7.1% and 11.9% to 5.7% and 8.9%, respectively, under baseline screening coverage of 44% per year. If screening coverage is increased to 60% per year, prevalence is predicted to be reduced to 3.6% and 6.7%, respectively, under conventional testing, and further reduced to 1.8% and 3.1% with the introduction of POC testing. Increasing screening coverage to 80% per year will result in a reduction in the prevalence of gonorrhoea and chlamydia to 0.6% and 1.5%, respectively, and the virtual elimination of both STIs if POC testing is introduced. Conclusions: Modelling suggests that molecular POC tests of high sensitivity have great promise as a public health strategy for controlling chlamydia and gonorrhoea. However, evaluation of the cost-effectiveness of POC testing needs to be made before widespread implementation of this technology can be considered. PMID:23806149
Hui, Ben B; Wilson, David P; Ward, James S; Guy, Rebecca J; Kaldor, John M; Law, Matthew G; Hocking, Jane S; Regan, David G
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
Background The clinical signs of active trachoma are often present in the absence of ocular Chlamydia trachomatis infection in low prevalence and mass treated settings. Treatment decisions are currently based on the prevalence of clinical signs, and this may result in the unnecessary distribution of mass antibiotic treatment. We aimed to evaluate the diagnostic accuracy of a prototype point-of-care (POC) test, developed for field diagnosis of ocular C. trachomatis, in low prevalence settings of The Gambia and Senegal. Methodology/Principal Findings Three studies were conducted, two in The Gambia and one in Senegal. Children under the age of 10 years were screened for the clinical signs of trachoma. Two ocular swabs were taken from the right eye. The first swab was tested by the POC test in the field and the result independently graded by two readers. The second swab was tested for the presence of C. trachomatis by Amplicor Polymerase Chain Reaction. In Senegal, measurements of humidity and temperature in the field were taken. A total of 3734 children were screened, 950 in the first and 1171 in the second Gambian study, and 1613 in Senegal. The sensitivity of the prototype POC test ranged between 33.3–67.9%, the specificity between 92.4–99.0%, the positive predictive value between 4.3–21.0%, and the negative predictive value between 98.0–99.8%. The rate of false-positives increased markedly at temperatures above 31.4°C and relative humidities below 11.4%. Conclusions/Significance In its present format, this prototype POC test is not suitable for field diagnosis of ocular C. trachomatis as its specificity decreases in hot and dry conditions: the environment in which trachoma is predominantly found. In the absence of a suitable test for infection, trachoma diagnosis remains dependent on clinical signs. Under current WHO recommendations, this is likely resulting in the continued mass treatment of non-infected communities.
Harding-Esch, Emma M.; Holland, Martin J.; Schemann, Jean-Francois; Molina, Sandra; Sarr, Isatou; Andreasen, Aura A.; Roberts, Chrissy h.; Sillah, Ansumana; Sarr, Boubacar; Harding, Edward F.; Edwards, Tansy; Bailey, Robin L.; Mabey, David C. W.
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
Point-of-care (POC) diagnostic tests for influenza can considerably shorten the time to clinical decision making. An investigational POC test based on a multiplexed immunoassay was developed by Meso Scale Diagnostics, LLC (MSD), with the objective to make a more sensitive rapid test that can also subtype influenza A viruses (1977 H1, H3, and H5). Between February and November 2010, we conducted a prospective multicenter study at four hospitals in Vietnam and compared the performance of this test to that of the WHO/CDC real-time reverse transcriptase PCR (RT-PCR) on nasal and throat swab specimens from patients presenting with influenza-like illness. Five hundred sixty-three adults and children with a median age of 25 months were enrolled. Sensitivity and specificity of the test with combined results from nasal and throat swab samples were 74.0% (131/177) and 99.7% (351/352), respectively, compared to RT-PCR. The POC test was as sensitive for influenza virus B as for influenza virus A (74.4% [64/86] versus 73.6% [67/91]). The positivity rate was associated with lower cycle threshold values (a marker for higher viral loads), sample type (73.6% for nasal swab versus 52.4% for throat swab), and younger age. A total of 210 (18.7%) out of 1,126 MSD tests failed, and for 34 (6%) of patients, both test samples failed (these were excluded from the performance analysis). Subtyping could be assessed only for influenza virus A/H3N2, as 1977 H1N1 was not circulating at the time and no H5N1-infected patients were enrolled, and was successful only in 9/54 patients infected with H3 influenza virus who had a positive POC test result for influenza virus A. This novel POC test provided highly sensitive detection of influenza viruses A and B compared to the reported sensitivities of other rapid tests. However, 18.7% of tests failed for technical reasons and subtyping for H3 was poor. Drawbacks to the technology include the requirement for a dedicated reader instrument and the need for continual updating of subtyping antibodies within the test array.
van Kinh, Nguyen; Tuan, Ha Manh; Tuan, Tran Anh; Minh, Ngo Ngoc Quang; Bryant, Juliet E.; Hang, Vu thi Ty; Uyen, Le thi Tham; Thinh, Le Quoc; Anh, Tran thi Ngoc; Lan, Nguyen Phu Huong; Trung, Nguyen Vu; Taylor, Walter; Merson, Laura; Wertheim, Heiman F. L.; Farrar, Jeremy; Wolbers, Marcel; Chau, Nguyen van Vinh; de Jong, Menno D.
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 Rapid and point-of-care (POC) tests for syphilis are an invaluable screening tool, yet inadequate evaluation of their diagnostic accuracy against best reference standards limits their widespread global uptake. To fill this gap, a systematic review and meta-analysis was conducted to evaluate the sensitivity and specificity of rapid and POC tests in blood and serum samples against Treponema pallidum (TP) specific reference standards. Methods Five electronic databases (1980–2012) were searched, data was extracted from 33 articles, and Bayesian hierarchical models were fit. Results In serum samples, against a TP specific reference standard point estimates with 95% credible intervals (CrI) for the sensitivities of popular tests were: i) Determine, 90.04% (80.45, 95.21), ii) SD Bioline, 87.06% (75.67, 94.50), iii) VisiTect, 85.13% (72.83, 92.57), and iv) Syphicheck, 74.48% (56.85, 88.44), while specificities were: i) Syphicheck, 99.14% (96.37, 100), ii) Visitect, 96.45% (91.92, 99.29), iii) SD Bioline, 95.85% (89.89, 99.53), and iv) Determine, 94.15% (89.26, 97.66). In whole blood samples, sensitivities were: i) Determine, 86.32% (77.26, 91.70), ii) SD Bioline, 84.50% (78.81, 92.61), iii) Syphicheck, 74.47% (63.94, 82.13), and iv) VisiTect, 74.26% (53.62, 83.68), while specificities were: i) Syphicheck, 99.58% (98.91, 99.96), ii) VisiTect, 99.43% (98.22, 99.98), iii) SD Bioline, 97.95%(92.54, 99.33), and iv) Determine, 95.85% (92.42, 97.74). Conclusions Rapid and POC treponemal tests reported sensitivity and specificity estimates comparable to laboratory-based treponemal tests. In resource limited settings, where access to screening is limited and where risk of patients lost to follow up is high, the introduction of these tests has already been shown to improve access to screening and treatment to prevent stillbirths and neonatal mortality due to congenital syphilis. Based on the evidence, it is concluded that rapid and POC tests are useful in resource limited settings with poor access to laboratories or screening for syphilis.
Jafari, Yalda; Peeling, Rosanna W.; Shivkumar, Sushmita; Claessens, Christiane; Joseph, Lawrence; Pai, Nitika Pant
Rationale and Objectives The Food and Drug Administration recommends renal function estimation using laboratory testing for patients at risk for chronically reduced kidney function before the administration of gadolinium-based contrast agents (GBCAs). Point-of-care (POC) estimated glomerular filtration rate (eGFR) testing was added to the pre-magnetic resonance (MR) questionnaire at our institution in June 2008 for all patients undergoing a contrast-enhanced MR exam. This study was done to evaluate the effectiveness of a pre-MR screening questionnaire about kidney disease and to assess POC eGFR detection of additional patients at risk for nephrogenic systemic fibrosis. Materials and Methods This retrospective study was approved by our institutional review board and determined to be Health Insurance Portability and Accountability Act compliant. Medical records, laboratory data, and pre-MR questionnaires of all patients who presented for contrast-enhanced MR scans during October 2008 were reviewed. The National Kidney Disease Education Program isotope-dilution mass spectrometry-traceable Modification of Diet in Renal Disease equation was used to calculate eGFRs using the POC creatinine laboratory value, age, race, and gender. Sensitivity and specificity were calculated using 2 × 2 tables, and 95% confidence intervals were calculated with exact binomial confidence intervals. Results A total of 1167 individuals presented for contrast-enhanced MR scans. Of 13 individuals on dialysis, 2 did not report renal disease. Of 1154 individuals not on dialysis, 25 had an eGFR <30 mL/min/1.73 m2 (95% CI 1.41%–3.18%). Of these 25, 13 did and 12 did not report renal disease. The sensitivity of the questionnaire for identifying patients with an eGFR <30 mL/min/1.73 m2 was 63.2%. POC eGFR estimations identified a prevalence of 2.17% (95% CI: 1.41%–3.18%) of the total individuals not on dialysis, with an eGFR <30 mL/min/1.73 m2. Patients who denied kidney dysfunction had a 1.08% (95% CI: 0.56%–1.88%) posttest probability of having an eGFR <30 mL/min/1.73 m2. Conclusions POC eGFR testing identified a significant number of individuals with renal dysfunction not found by the pre-MR imaging questionnaire alone.
Chang, Philip; Saddleton, Elise; Laumann, Anne E.; Schmitz, Brenda; West, Dennis P.; Belknap, Steven M.; Parthasarathy, Sudharshan; Edwards, Beatrice J.; McKoy, June M.; Miller, Frank H.
Loop-mediated isothermal amplification (LAMP) is a novel molecular method that accelerates and facilitates DNA amplification and detection under isothermal conditions. It represents a revolution in molecular biology by reducing the high cost, turnaround time and technicality of polymerase chain reaction and other amplification methods. It has been applied for the diagnosis of a variety of viral, bacterial, parasitic and other diseases in the biomedical field. LAMP has been involved in studies concerning the diagnosis of malaria which is still a major cause of morbidity and mortality in different parts of the world. For the success attained with this technology to diagnose human malaria, is it time to think that LAMP-based point-of-care diagnostics come to application to support the diagnosis of clinical malaria cases? The present review deals with the use of LAMP in the diagnosis of malaria and related investigations to make a view on what has been investigated and highlights the future perspectives regarding the possible applications of LAMP in diagnosis of the disease. PMID:22366670
Abdul-Ghani, Rashad; Al-Mekhlafi, Abdulsalam M; Karanis, Panagiotis
The diabetes epidemic is accelerating rapidly. If no progress is made in early detection, then early intervention and treatment-to-goal diabetes care will become an overwhelming burden on our health care system. Better utilization of self-monitoring of blood glucose in patients with type 2 diabetes not on insulin could be achieved with regular review of hemoglobin A1c (A1C) values. Educating patients about the importance of diet, exercise, and medication compliance is enhanced when evidence of average blood glucose control can be presented to the patient directly. Affordable, accurate point-of-care testing of A1C with A1cNow+ (Bayer HealthCare, Terrytown, NY) utilized in pharmacist-managed outpatient diabetes programs may prove to be an important clinical tool for improving patient outcomes and reducing the cost of the expanding diabetes epidemic. PMID:19885268
Carter, Alan W
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
Currently, there is no routine monitoring of an immune response to the anthrax vaccine. Simple on-site tests are needed to evaluate the antibody response of anthrax-vaccinated individuals in the Armed Forces and others at high risk. Using a prototype lateral flow assay (LFA) (R. E. Biagini, D. L. Sammons, J. P. Smith, B. A. MacKenzie, C. A. F. Striley, J.
Diane R. Bienek; Raymond E. Biagini; David G. Charlton; Jerome P. Smith; Deborah L. Sammons; Shirley A. Robertson
BackgroundUK guidance recommend all acute medical admissions be offered an HIV test. Our aim was to determine whether a dedicated staff member using a multimedia tool, a model found to be effective in the USA, is an acceptable, feasible, and cost-effective model when translated to a UK setting.DesignBetween 14th Jan to 12th May 2010, a Health advisor (HA) approached 19–65
Fiona Burns; Simon G. Edwards; Jeremy Woods; Golaleh Haidari; Yvette Calderon; Jason Leider; Stephen Morris; Rose Tobin; Jonathan Cartledge; Michael Brown
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
PURPOSE The purpose of the study was to assess the long-term effect of family physicians’ use of C-reactive protein (CRP) point-of-care testing and/or physician training in enhanced communication skills on office visit rates and antibiotic prescriptions for patients with respiratory tract infections. METHODS We conducted a 3.5-year follow-up of a pragmatic, factorial, cluster-randomized controlled trial; 379 patients (20 family practices in the Netherlands) who visited their family physician for acute cough were enrolled in the trial and had follow-up data available (88% of original trial cohort). Main outcome measures were the average number of episodes of respiratory tract infections for which patients visited their family physician per patient per year (PPPY), and the percentage of the episodes for which patients were treated with antibiotics during follow-up. RESULTS The mean number of episodes of respiratory tract infections during follow-up was 0.40 PPPY in the CRP test group and 0.56 PPPY in the no CRP test group (P = .12). In the communication skills training group, there was a mean of 0.36 PPPY episodes of respiratory tract infections, and in the no training group the mean was 0.57 PPPY (P = .09). During follow-up 30.7% of all episodes of respiratory tract infection were treated with antibiotics in the CRP test group compared with 35.7% in the no test group (P = .36). Family physicians trained in communication skills treated 26.3% of all episodes of respiratory tract infection with antibiotics compared with 39.1% treated by family physicians without training in communication skills (P = .02) CONCLUSIONS Family physicians’ use of CRP point-of-care testing and/or training in enhanced communication skills did not significantly affect office visit rates related to respiratory tract infections. Patients who saw a family physician trained in enhanced communication skills were prescribed significantly fewer antibiotics during episodes of respiratory tract infection in the subsequent 3.5 years.
Cals, Jochen W. L.; de Bock, Leon; Beckers, Pieter-Jan H. W.; Francis, Nick A.; Hopstaken, Rogier M.; Hood, Kerenza; de Bont, Eefje G. P. M.; Butler, Christopher C.; Dinant, Geert-Jan
Many of the target molecules that reside in blood are also present in oral fluids, albeit at lower concentrations. Oral fluids are, however, relatively easy and safe to collect without the need for specialized equipment and training. Thus, oral fluids provide convenient samples for medical diagnostics. Recent advances in lab-on-a-chip technologies have made minute, fully integrated diagnostic systems practical for an assortment of point-of-care tests. Such systems can perform either immunoassays or molecular diagnostics outside centralized laboratories within time periods ranging from minutes to an hour. The article briefly reviews recent advances in devices for point-of-care testing with a focus on work that has been carried out by the authors as part of a NIH program. PMID:21521419
Hart, R W; Mauk, M G; Liu, C; Qiu, X; Thompson, J A; Chen, D; Malamud, D; Abrams, W R; Bau, H H
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. PMID:23112587
Adiguzel, Yekbun; Kulah, Haluk
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
Impact from point-of-care devices on emergency department patient processing times compared with central laboratory testing of blood samples: a randomised controlled trial and cost-effectiveness analysis.
OBJECTIVE: To determine if time to disposition decisions for emergency department (ED) patients can be reduced when blood tests are processed using point-of-care (POC) devices and to conduct a cost-effectiveness analysis of POC compared with laboratory testing. METHODS: This randomised trial enrolled adults suspected of an acute coronary syndrome or presenting with conditions considered to only require blood tests available by POC. Participants were randomised to have blood tests processed by POC or laboratory. Outcomes measured were time to disposition decision and ED length-of-stay (LOS). The cost-effectiveness analysis calculated the total and mean costs per ED presentation, as well as total and mean benefits in time saved to disposition decision. RESULTS: There were 410 POC participants and 401 controls. The mean times to a disposition decision for POC versus controls were 3.24 and 3.50 h respectively, a difference of 7.6% (95% CI 0.4% to 14.3%, p=0.04), and 4.32 and 4.52 h respectively for ED LOS, a difference of 4.4% (95% CI -2.7% to 11.0%, p=0.21). Improved processing time was greatest for participants enrolled by senior staff with a reduction in time to disposition decision of 19.1% (95% CI 7.3% to 29.4%, p<0.01) and ED LOS of 15.6% (95% CI 4.9% to 25.2%, p=0.01). Mean pathology costs were $12 higher in the POC group (95% CI $7 to $18) and the incremental cost-effectiveness ratio was $113 per hour saved in time to disposition decision for POC compared with standard laboratory testing. CONCLUSIONS: Small improvements in disposition decision time were achieved with POC testing for a moderate increase in cost. Greatest benefit may be achieved when POC is targeted to senior medical staff. PMID:23748157
Asha, Stephen Edward; Chan, Adam Chiu Fat; Walter, Elizabeth; Kelly, Patrick J; Morton, Rachael L; Ajami, Allan; Wilson, Roger Denis; Honneyman, Daniel
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
Recent developments in nanotechnology have led to significant advancements in point-of-care (POC) nucleic acid detection. The ability to sense DNA and RNA in a portable format leads to important applications for a range of settings, from on-site detection in the field to bedside diagnostics, in both developing and developed countries. We review recent innovations in three key process components for nucleic acid detection: sample preparation, target amplification, and read-out modalities. We discuss how the advancements realized by nanotechnology are making POC nucleic acid detection increasingly applicable for decentralized and accessible testing, in particular for the developing world. PMID:24057263
Hartman, Mark R; Ruiz, Roanna C H; Hamada, Shogo; Xu, Chuanying; Yancey, Kenneth G; Yu, Yan; Han, Wei; Luo, Dan
Recent developments in nanotechnology have led to significant advancements in point-of-care (POC) nucleic acid detection. The ability to sense DNA and RNA in a portable format leads to important applications for a range of settings, from on-site detection in the field to bedside diagnostics, in both developing and developed countries. We review recent innovations in three key process components for nucleic acid detection: sample preparation, target amplification, and read-out modalities. We discuss how the advancements realized by nanotechnology are making POC nucleic acid detection increasingly applicable for decentralized and accessible testing, in particular for the developing world.
Hartman, Mark R.; Ruiz, Roanna C. H.; Hamada, Shogo; Xu, Chuanying; Yancey, Kenneth G.; Yu, Yan; Han, Wei; Luo, Dan
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
Improving the access to effective and affordable healthcare has long been a global endeavor. In this quest, the development of cost-effective and easy-to-use medical testing equipment that enable rapid and accurate diagnosis is essential to reduce the time and costs associated with healthcare services. To this end, point-of-care (POC) diagnostics plays a crucial role in healthcare delivery in both the developed and developing countries by bringing medical testing to patients, or to sites near patients. As the diagnosis of a wide range of diseases, including various types of cancers and many endemics relies on optical techniques, numerous compact and cost-effective optical imaging platforms have been developed in recent years for use at the POC. Here, we review the state-of-the-art optical imaging techniques that can have significant impact on global health by facilitating effective and affordable POC diagnostics.
Zhu, Hongying; Isikman, Serhan O.; Mudanyali, Onur; Greenbaum, Alon; Ozcan, Aydogan
Introduction: Internet point of care (PoC) learning is a relatively new method for obtaining continuing medical education credits. Few data are available to describe physician utilization of this CME activity. Methods: We describe the Internet point of care system we developed at a medium-sized community hospital and report on its first year of…
|Introduction: Internet point of care (PoC) learning is a relatively new method for obtaining continuing medical education credits. Few data are available to describe physician utilization of this CME activity. Methods: We describe the Internet point of care system we developed at a medium-sized community hospital and report on its first year of…
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: The number of indications for recombinant human hirudin lepirudin therapy has increased in recent years, and now includes acute coronary syndromes and heparin-induced thrombocytopenia. Hence, point of care monitoring appears desirable for therapy with lepirudin. As CoaguChek Plus (CCP) provides a rapid bedside test to monitor therapy with other anticoagulants, we aimed to determine its suitability for lepirudin therapy.
Monika Homoncik; Thomas Pernerstorfer; Rosemarie Reiter; Maarten Knechtelsdorfer; Peter Quehenberger; Bernd Jilma
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
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.
Evidence-based practice at the point of care gives advance practice registered nurses and their patients immediate access to the most current evidence and research-backed information to treat the specific issue or health concern with which the patient presents. Patients without current complaints, but with questions and concerns can receive education regarding current preventive guidelines and recommendations for many illnesses, such
Rick Amend; Angela Golden
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
ClinicalKey is a new point-of-care resource for health care professionals. Through controlled vocabulary, ClinicalKey offers a cross section of resources on diseases and procedures, from journals to e-books and practice guidelines to patient education. A sample search was conducted to demonstrate the features of the database, and a comparison with similar tools is presented. PMID:23394422
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
Blood analyses are the most common clinical diagnostic methods. Lab-on-a-chip technology, stemmed from concepts of microsystem microfabrication and microfluidics, provides an automatic, rapid, cost-effective and point-of-care solution for a wide variety of blood analyses. In general, blood separation is the first step for subsequent blood tests in clinical diagnosis. In this study, a rapid prototyping of out-of-plane valves using low
Tingjie Li; Qiuquan Guo; Limin Zhang; Jun Yang
Six assays were evaluated in this study to determine their suitability for the diagnosis of acute dengue infection using samples from 259 Sri Lankan patients with acute fevers (99 confirmed dengue cases and 160 patients with other confirmed acute febrile illnesses): (i) the Merlin dengue fever IgG & IgM combo device (Merlin), (ii) the Standard Diagnostics Dengue Duo nonstructural 1 (NS1) antigen and IgG/IgM combo device (Standard Diagnostics, South Korea), (iii) the Biosynex Immunoquick dengue fever IgG and IgM (Biosynex, France) assay, (iv) the Bio-Rad NS1 antigen strip (Bio-Rad, France), (v) the Panbio Dengue Duo IgG/IgM Cassette (Inverness, Australia), and (vi) the Panbio dengue NS1 antigen strip (Inverness, Australia). The median number of days of fever prior to admission sample collection was 5 days (interquartile range, 3 to 7 days). Sensitivity and specificity of the NS1 antigen tests ranged from 49 to 59% and from 93 to 99%, respectively, and sensitivity and sensitivity of the IgM antibody test ranged from 71 to 80% and from 46 to 90%, respectively. Combining the NS1 antigen and IgM antibody results from the Standard Diagnostics Dengue Duo test gave the best compromise of sensitivity and specificity (93% and 89%, respectively) and provided the best sensitivity in patients presenting at different times after fever onset. The Merlin IgM/IgG antibody tests correctly classified 64% and 86% of the primary and secondary dengue infection cases, respectively, and the Standard Diagnostics IgM/IgG antibody tests correctly classified 71% and 83% of the primary and secondary dengue infection cases, respectively. This study provides strong evidence of the value of combining dengue antigen- and antibody-based test results in the rapid diagnostic test (RDT) format for the acute diagnosis of dengue. PMID:22012979
Blacksell, Stuart D; Jarman, Richard G; Bailey, Mark S; Tanganuchitcharnchai, Ampai; Jenjaroen, Kemajittra; Gibbons, Robert V; Paris, Daniel H; Premaratna, Ranjan; de Silva, H Janaka; Lalloo, David G; Day, Nicholas P J
Evaluation of Six Commercial Point-of-Care Tests for Diagnosis of Acute Dengue Infections: the Need for Combining NS1 Antigen and IgM/IgG Antibody Detection To Achieve Acceptable Levels of Accuracy ?†
Six assays were evaluated in this study to determine their suitability for the diagnosis of acute dengue infection using samples from 259 Sri Lankan patients with acute fevers (99 confirmed dengue cases and 160 patients with other confirmed acute febrile illnesses): (i) the Merlin dengue fever IgG & IgM combo device (Merlin), (ii) the Standard Diagnostics Dengue Duo nonstructural 1 (NS1) antigen and IgG/IgM combo device (Standard Diagnostics, South Korea), (iii) the Biosynex Immunoquick dengue fever IgG and IgM (Biosynex, France) assay, (iv) the Bio-Rad NS1 antigen strip (Bio-Rad, France), (v) the Panbio Dengue Duo IgG/IgM Cassette (Inverness, Australia), and (vi) the Panbio dengue NS1 antigen strip (Inverness, Australia). The median number of days of fever prior to admission sample collection was 5 days (interquartile range, 3 to 7 days). Sensitivity and specificity of the NS1 antigen tests ranged from 49 to 59% and from 93 to 99%, respectively, and sensitivity and sensitivity of the IgM antibody test ranged from 71 to 80% and from 46 to 90%, respectively. Combining the NS1 antigen and IgM antibody results from the Standard Diagnostics Dengue Duo test gave the best compromise of sensitivity and specificity (93% and 89%, respectively) and provided the best sensitivity in patients presenting at different times after fever onset. The Merlin IgM/IgG antibody tests correctly classified 64% and 86% of the primary and secondary dengue infection cases, respectively, and the Standard Diagnostics IgM/IgG antibody tests correctly classified 71% and 83% of the primary and secondary dengue infection cases, respectively. This study provides strong evidence of the value of combining dengue antigen- and antibody-based test results in the rapid diagnostic test (RDT) format for the acute diagnosis of dengue.
Blacksell, Stuart D.; Jarman, Richard G.; Bailey, Mark S.; Tanganuchitcharnchai, Ampai; Jenjaroen, Kemajittra; Gibbons, Robert V.; Paris, Daniel H.; Premaratna, Ranjan; de Silva, H. Janaka; Lalloo, David G.; Day, Nicholas P. J.
Newborn screening is performed under public health authority, with analysis carried out primarily by public health laboratories or other centralized laboratories. Increasingly, opportunities to improve infant health will arise from including screening tests that are completed at the birth centers instead of in centralized laboratories, constituting a significant shift for newborn screening. This report summarizes a framework developed by the US Secretary of Health and Human Services Advisory Committee on Heritable Disorders in Newborns and Children based on a series of meetings held during 2011 and 2012. These meetings were for the purpose of evaluating whether conditions identifiable through point-of-care screening should be added to the recommended universal screening panel, and to identify key considerations for birth hospitals, public health agencies, and clinicians when point-of-care newborn screening is implemented. PMID:22899090
Kemper, Alex R; Kus, Christopher A; Ostrander, Robert J; Comeau, Anne Marie; Boyle, Coleen A; Dougherty, Denise; Mann, Marie Y; Botkin, Jeffrey R; Green, Nancy S
This is a case report of a superficial penile hematoma that was difficult to distinguish clinically from a penile fracture. Such cases occur with relative frequency, and because definitive treatment is an urgent surgery, timely diagnosis is essential to avoid complications. Typical imaging modalities such as cavernosonography and magnetic resonance imaging can be invasive (cavernosonography) or time consuming (magnetic resonance imaging) and may not be readily available. Ultrasound has been used successfully in such cases, and, in this case, we used point-of-care ultrasound combined with a brief period of observation to exclude penile fracture.
Advances in optical designs are enabling the development of miniature microscopes that can examine tissue in situ for early anatomic and molecular indicators of disease, in real time, and at cellular resolution. These new devices will lead to major changes in how diseases are detected and managed, driving a shift from today’s diagnostic paradigm of biopsy followed by histopathology and recommended therapy, to non-invasive point-of-care diagnosis with possible same-session definitive treatment. This shift may have major implications for the training requirements of future physicians to enable them to interpret real-time in vivo microscopic data, and will also shape the emerging fields of telepathology and telemedicine. Implementation of new technologies into clinical practice is a complex process that requires bridging gaps between clinicians, engineers and scientists. This article provides a forward-looking discussion of these issues, with a focus on malignant and pre-malignant lesions, by first highlighting some of the clinical areas where point-of-care in vivo microscopy could address unmet needs, and then by reviewing the technological challenges that are being addressed, or need to be addressed, for in vivo microscopy to become a standard clinical tool.
Liu, Jonathan T.C.; Loewke, Nathan O.; Mandella, Michael J.; Levenson, Richard M.; Crawford, James M.; Contag, Christopher H.
Analysis: New Point-of-Care Blood Glucose Monitoring System for the Hospital Demonstrates Satisfactory Analytical Accuracy Using Blood from Critically Ill Patients-An Important Step toward Improved Blood Glucose Control in the Hospital.
Patients managed in the intensive care units (ICUs) and general wards of the hospital experience a high incidence of hyperglycemia, hypoglycemia, and glycemic variability, despite significant hospital resources devoted to glucose control. Optimized glucose meters and monitoring systems are required to improve the safety and efficacy of insulin delivery and glucose control in the hospital. Safe insulin dosing requires timely and accurate glucose measurements, especially during dynamic changes in nutrition, insulin sensitivity, and physiological stress. In the current issue of Journal of Diabetes Science and Technology, Mitsios and coauthors describe the analytical accuracy of the new Accu-Check® Inform II blood glucose (BG) monitoring system commercialized by F. Hoffmann-La Roche Ltd. The point-of-care glucose meter achieved the desired degree of accuracy and precision, as defined by Clinical and Laboratory Standards Institute POCT12-A3 guidelines when evaluated using venous blood from 600 critically ill patients from multiple ICUs at two medical centers. Venous whole blood samples were used to obtain glucose meter results in duplicate. The remaining blood sample was centrifuged to obtain plasma for central hospital laboratory testing using the hexokinase method within 5 min of meter testing. A total of 98.8% of the 1200 Accu-Check Inform II meter's glucose values were within ±12.5% (±12 mg/dl) of the mean laboratory glucose value, and 99.8% were within ±20% (±20 mg/dl), thus meeting the Clinical and Laboratory Standards Institute criteria. Future studies are required to evaluate the clinical performance of the new BG monitoring system in the intended-use patient populations and critical care environments, using arterial, peripheral venous, central venous, and capillary blood samples. PMID:24124956
Joseph, Jeffrey I
The Department of Cardiovascular Surgery at East Alabama Medical Center (EAMC) initiated a program in 1996 to improve the quality and usefulness of clinical outcomes data. After years of using a commercial vendor product and enduring a tedious collection process, the department decided to develop its own tools to support quality improvement efforts. Using a hand-held personal data assistant (PDA), the team developed tools that allowed ongoing data collection at the point of care delivery. The tools and methods facilitated the collection of real time, accurate information that allowed EAMC to participate in multiple clinical quality initiatives. The ability to conduct rapid-cycle performance improvement studies propelled EAMC's Cardiovascular Surgery Program into the Top 100 as recognized by HCIA, now Solucient, for 3 consecutive years (1999-2001). This report will describe the evolution of the data collection process as well as the quality improvements that resulted. PMID:12747135
Obtaining immediate results makes testing for albuminuria at the point of care far superior to central laboratory assays. Here we determined if a quantitative desk-top system could identify and monitor patients with microalbuminuria. Urinary albumin excretion was measured in 259 patients of a population cohort study where they collected 24-h urines and first morning void samples prior to three clinic
Hiddo J Lambers Heerspink; Elsbeth C Witte; Stephan J L Bakker; Paul E de Jong; Dick de Zeeuw; Ron T Gansevoort
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
The development of new point of care coagulation assay devices is necessary due to the increasing number of patients requiring long-term anticoagulation in addition to the desire for appropriate, targeted anticoagulant therapy and a more rapid response to optimization of treatment. The majority of point of care devices currently available for hemostasis testing rely on clot-based endpoints which are variable, unreliable and limited to measuring only certain portions of the coagulation pathway. Here we present a novel fluorescence-based anti-Factor Xa (FXa) microfluidic assay device for monitoring the effect of anticoagulant therapy at the point of care. The device is a disposable, laminated polymer microfluidic strip fabricated from a combination of hydrophobic and hydrophilic cyclic polyolefins to allow reagent deposition in addition to effective capillary fill. Zeonor was the polymer of choice resulting in low background fluorescence (208.5 AU), suitable contact angles (17.5°± 0.9°) and capillary fill times (20.3 ± 2.1 s). The device was capable of measuring unfractionated heparin and tinzaparin from 0-0.8 U ml(-1) and enoxaparin from 0-0.6 U ml(-1) with average CVs < 10%. A linear correlation was observed between the device and the fluorescent assay in the plate for plasma samples spiked with UFH, with an R(2) value of 0.99, while correlations with tinzaparin and enoxaparin resulted in sigmoidal responses (R(2) = 0.99). Plasma samples containing UFH resulted in a linear correlation between the device and a standard chromogenic assay with an R(2) value of 0.98, with both LMWHs resulting in sigmoidal relationships (R(2) = 0.99). PMID:23666610
Harris, Leanne F; Rainey, Paul; Castro-López, Vanessa; O'Donnell, James S; Killard, Anthony J
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. PMID:22538154
Rebel, Annette; Rice, Mark A; Fahy, Brenda G
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
Recent advances in MEMS technology have provided an opportunity to develop microfluidic devices with enormous potential for portable, point-of-care, low-cost medical diagnostic tools. Hand-held flow cytometers will soon be used in disease diagnosis and monitoring. Despite much interest in miniaturizing commercially available cytometers, they remain costly, bulky, and require expert operation. In this article, we report progress on the development of a battery-powered handheld blood analyzer that will quickly and automatically process a drop of whole human blood by real-time, on-chip magnetic separation of white blood cells (WBCs), fluorescence analysis of labeled WBC subsets, and counting a reproducible fraction of the red blood cells (RBCs) by light scattering. The whole blood (WB) analyzer is composed of a micro-mixer, a special branching/separation system, an optical detection system, and electronic readout circuitry. A droplet of un-processed blood is mixed with the reagents, i.e. magnetic beads and fluorescent stain in the micro-mixer. Valve-less sorting is achieved by magnetic deflection of magnetic microparticle-labeled WBC. LED excitation in combination with an avalanche photodiode (APD) detection system is used for counting fluorescent WBC subsets using several colors of immune-Qdots, while counting a reproducible fraction of red blood cells (RBC) is performed using a laser light scatting measurement with a photodiode. Optimized branching/channel width is achieved using Comsol Multi-Physics™ simulation. To accommodate full portability, all required power supplies (40v, +/-10V, and +3V) are provided via step-up voltage converters from one battery. A simple onboard lock-in amplifier is used to increase the sensitivity/resolution of the pulse counting circuitry.
Maleki, Teimour; Fricke, Todd; Quesenberry, J. T.; Todd, Paul W.; Leary, James F.
A CD4 T-lymphocyte count determines eligibility for antiretroviral therapy (ART) in 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 because 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 the facilitation of ART and monitoring of treatment. This review highlights recent technology developments with applications towards determining CD4 counts at the POC. PMID:21798607
Boyle, David S; Hawkins, Kenneth R; Steele, Matthew S; Singhal, Mitra; Cheng, Xuanhong
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 continue 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. PMID:23357365
Wang, ShuQi; Inci, Fatih; De Libero, Gennaro; Singhal, Amit; Demirci, Utkan
We conducted three health care evaluation studies in community and hospital settings to examine adoption of point-of-care documentation systems among interdisciplinary care team clinicians. Both community studies used a mixed methods design to assess actual system usage and clinician satisfaction. In the hospitals, scenario testing was used. Results indicated clinician adoption of the systems was universal, although not always timely with: (1) a mismatch between system functionality and workflow which was a barrier to clinician system access during patient care and reduced clinician efficiency; (2) no increase in interdisciplinary team communication; and (3) no impact on patient outcomes identified by clinicians. To facilitate adoption, clinicians should see the value of using the system as intended by receiving patient care and patient safety feedback that uses system data. PMID:23920713
Sockolow, Paulina S; Bowles, Kathryn H; Rogers, Michelle; Adelsberger, Marguerite C; Chittams, Jesse L; Liao, Cindy
An innovative vacuum capillary pneumatic actuation concept that can be used for point-of-care testing has been investigated. The vacuum glass capillaries are encapsulated within a laminated pouch and incorporated into the fluidic card. Vacuum glass capillaries broken by external force such as finger pressure, generate the pneumatic forces to induce liquid flow in the fluidic system. The sizes of vacuum capillary play a vital role in the pumping and metering functions of the system. The luteinizing hormone (LH) chromatographic immunoassay performances in the fluidic cards show consistency comparable to that obtained by manual micropipetting. The vacuum capillary pneumatic actuation will be applied in other complex handling step bioassays and lab-on-a-chip devices. PMID:18584101
Weng, Kuo-Yao; Chou, Nien-Jen; Cheng, Jya-Wei
A major requirement for the development of point-of-care tests for the detection of disease analytes is the need to separate plasma from whole blood in an efficient and rapid manner. Furthermore, the separated plasma must be able to elute efficiently the analyte of interest and serve effectively as a physical matrix to deliver the equivalent of neat plasma for downstream diagnostic analysis. Additionally, many applications require the use of heat shock to liberate immunocomplexed antigen found in the collected plasma. A membrane-based filter method is reported for rapid and efficient collection of plasma from a whole blood sample that is compatible with heat shock. Using pediatric human immunodeficiency virus as an example, this device elutes 100% of the input p24 core antigen post-collection and enables heat shock of plasma samples identical to neat plasma treatment. PMID:21219933
Nabatiyan, Arman; Parpia, Zaheer A; Elghanian, Robert; Kelso, David 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
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
...willingness to participate in Point-of-Care Research (POC-R). POC-R is an intermediary approach to bridge the gap between clinical trials and observation studies. The POC-R provides a potential mechanism for improving the...
Diagnosis represents only one aspect of tuberculosis (TB) control but is perhaps one of the most challenging. The drawbacks of current tools highlight several unmet needs in TB diagnosis, that is, necessity for accuracy, rapidity of diagnosis, affordability, simplicity and the ability to generate same-day results at point-of-care (POC). When a return visit is required to access test results, time to treatment is prolonged, and default rates are significant. However, a good diagnostic tool is also critically dependent on obtaining an adequate biological sample. Here, we review the accuracy and potential impact of established and newer potential POC diagnostic tests for TB, including smear microscopy, the Xpert MTB/RIF assay (Cepheid) and the Determine TB lipoarabinomannan antigen test (Alere). Novel experimental approaches and detection technologies for POC diagnosis of active TB, including nucleic acid amplification tests, detection of volatile organic compounds or metabolites, mass spectroscopy, microfluidics, surface-enhanced Raman spectroscopy, electrochemical approaches, and aptamers among others, are discussed. We also discuss future applications, including the potential POC diagnosis of drug-resistant TB and presumed latent TB infection. Challenges to the development and roll-out of POC tests for TB are also reviewed. PMID:23190246
Dheda, Keertan; Ruhwald, Morten; Theron, Grant; Peter, Jonathan; Yam, Wing Cheong
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
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
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.
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
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
A simple platform for enumeration of human pathogens is greatly needed for infectious disease diagnostics, particularly in resource-limited settings. Viruses such as HIV present a particular challenge due to low levels in body fluids and sub-micron size, but techniques for quantification can be achieved with bio-micro/nanotechnology. Toward this goal of a rapid, low-cost point-of-care platform for viral load measurements, we demonstrate an amplification technique based on sensing of liposome tags. Liposomes are prepared by hydration of dipalmitoylphosphatidylcholine (DPPC) film with PBS, redistribution at a range of concentrations, and lysis in hypotonic media which frees encapsulated ions and alters conductivity of the solution. Impedance spectra are obtained with an LCR meter and microfluidic device patterned with inter-digitated electrodes. The resulting measurements are shown to relate to liposome number, demonstrating the utility of this technique for an assay in which the liposome functions as a tag for smaller particles. Real-time monitoring of liposome lysis demonstrates the basis for a rapid diagnostic test. These liposomes can be conjugated to IgG antibody to produce specificity for antigens such as HIV gp120 as the basis for a future impedance-based viral load device.
Damhorst, Gregory; Smith, Cartney; Salm, Eric; Ni, Hengkan; Hassan, Umer; Kong, Hyun Joon; Bashir, Rashid
This paper describes how sixteen partners from eight different countries across Europe are working together in two EU projects focused on the development of a point of care system. This system uses disposable Lab on a Chips (LOCs) that carry out the complete assay from sample preparation to result interpretation of raw samples. The LOC is either embedded in a flexible motherboard with the form of a smartcard (Labcard) or in a Skinpatch. The first project, OPTOLABCARD, extended and tested the use of a thick photoresit (SU-8) as a structural material to manufacture LOCs by lamination. This project produced several examples where SU-8 microfluidic circuitry revealed itself as a viable material for several applications, such as the integration on chip of a Polymerase Chain Reaction (PCR) that includes sample concentration, PCR amplification and optical detection of Salmonella spp. using clinical samples. The ongoing project, LABONFOIL, is using two results of OPTOLABCARD: the sample concentration method and the capability to fabricate flexible and ultra thin LOCs based on sheets instead of wafers. This rupture from the limited and expensive wafer surface heritage allows the development of a platform where LOCs are big enough to include all the sample preparation subcomponents at a low price. These LOCs will be used in four point of care applications: environment, food, cancer and drug monitoring. The user will obtain the results of the tests by connecting the Labcard/Skinpatch reader to a very popular interface (a smartphone), creating a new instrument namely "The SmartBioPhone". All standard smartphone capabilities will be at the disposal of the point of care instrument by a simple click. In order to guarantee the future mass production of these LOCs, the project will develop a large dry film equipment where LOCs will be fabricated at a low cost. PMID:19458852
Ruano-López, Jesus M; Agirregabiria, Maria; Olabarria, Garbiñe; Verdoy, Dolores; Bang, Dang D; Bu, Minqiang; Wolff, Anders; Voigt, Anja; Dziuban, Jan A; Walczak, Rafa?; Berganzo, Javier
Purpose The ability to assess the brain-at-risk during carotid endarterectomy (CEA) under general anesthesia remains a major clinical\\u000a problem. Point-of-care monitoring can potentially dictate changes to management intraoperatively. In this observational study,\\u000a we examined the correlation between a series of point-of-care monitors and lactate flux during CEA.\\u000a \\u000a \\u000a \\u000a \\u000a Methods Both neurosurgeons and vascular surgeons participated in the study. The patients underwent arterial-jugular venous
Ainsley E. G. Espenell; Ian W. McIntyre; Harleena Gulati; Linda G. Girling; Marshall F. Wilkinson; Joseph A. Silvaggio; Joshua Koulack; Michael West; Gregory E. J. Harding; Anthony M. Kaufmann; W. Alan C. Mutch
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™ (r(2)?=?0.762, mean bias -64.8 cells/µl), and the BD FACSCount™ (r(2)?=?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™ (r(2)?=?0.781, mean bias -24.2 cells/µl) and GUAVA™ (r(2)?=?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. PMID:23825674
Mwau, Matilu; Adungo, Ferdinard; Kadima, Silvia; Njagi, Ephantus; Kirwaye, Carolyne; Abubakr, Najma Salim; Okubi, Lucy Atsieno; Waihenya, Mary; Lusike, Judi; Hungu, Jackson
As a small portable instrument, which can be dedicated to the perfusionist, the Radiometer model ABL-77 point-of-care blood gas, electrolyte, and hematocrit analyzer has come to provide an alternative to in-line monitoring of such parameters. This is not to say that it can necessarily replace the utility of in-line monitoring. However, point of care instruments, such as the ABL-77, can provide faster results than a more remote lab. This study was done as part of an ongoing quality assurance program in conjunction with the main lab department to maintain accreditation. The hypothesis being tested is that during cardiopulmonary bypass (CPB) the ABL-77 is in agreement with alternative instruments used outside the cardiovascular operating room. With the appropriate institutional approval, a total of 20 blood samples were randomly gathered among five patients after initiation of CPB. This was done over a five-day period for pH, pCO2, pO2, potassium, sodium, and hematocrit determinations. Analysis results from the ABL-77 were compared to those made by three other bench top models. These included a Radiometer model ABL-720 analyzer, a Dale Dimension model RxL analyzer, and a Beckerman model LH 750 Coulter Counter. A statistically significant difference is demonstrated for all parameters when each of these instruments is compared to the ABL-77. However, the observed mean differences are only judged to be clinically significant in the case of hematocrit. The ABL-77 is found to demonstrate a negative bias with respect to the different methodologies used by the ABL-720 and the Coulter Counter. This bias may be due to the hemodilution of plasma with crystalloid solution during CPB. This causes error in hematocrit results as the methodology of many point of care instruments is based on the electrical conductivity of whole blood. This may be corrected by using a relationship determined from linear regression analysis. This error adjustment has been implemented as part of a concerted blood conservation effort. Otherwise, the ABL-77 has been found to be reliable and consistent for point of care blood analysis. PMID:16921685
Prichard, Jack S; French, John S; Alvar, Nestor
Immunoassays have been widely used in commercial, scientific and medical research for detection and quantification of analytes in complex mixtures. There is however a need for a point-of-care, multiplex diagnostic assays capable of providing rapid and quantitative measurements of analytes present in samples that are sufficiently simple to carry out without use of a laboratory or individuals trained in chemical
R. S. Rao; J. S. Albala; D. L. Matthews; A. M. Fisher; J. L. Lambert; M. A. Coleman
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
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.
Background Busy clinicians need easy access to evidence-based information to inform their clinical practice. Publishers and organizations have designed specific tools to meet doctors’ needs at the point of care. Objective The aim of this study was to describe online point-of-care summaries and evaluate their breadth, content development, and editorial policy against their claims of being “evidence-based.” Methods We searched Medline, Google, librarian association websites, and information conference proceedings from January to December 2008. We included English Web-based point-of-care summaries designed to deliver predigested, rapidly accessible, comprehensive, periodically updated, evidence-based information to clinicians. Two investigators independently extracted data on the general characteristics and content presentation of summaries. We assessed and ranked point-of-care products according to: (1) coverage (volume) of medical conditions, (2) editorial quality, and (3) evidence-based methodology. We explored how these factors were associated. Results We retrieved 30 eligible summaries. Of these products, 18 met our inclusion criteria and were qualitatively described, and 16 provided sufficient data for quantitative evaluation. The median volume of medical conditions covered was 80.6% (interquartile range, 68.9% - 84.2%) and varied for the different products. Similarly, differences emerged for editorial policy (median 8.0, interquartile range 5.8 - 10.3) and evidence-based methodology scores (median 10.0, interquartile range 1.0 - 12.8) on a 15-point scale. None of these dimensions turned out to be significantly associated with the other dimensions (editorial quality and volume, Spearman rank correlation r = -0.001, P = .99; evidence-based methodology and volume, r = -0.19, P = .48; editorial and evidence-based methodology, r = 0.43, P =.09). Conclusions Publishers are moving to develop point-of-care summary products. Some of these have better profiles than others, and there is room for improved reporting of the strengths and weaknesses of these products.
Liberati, Alessandro; Moschetti, Ivan; Tagliabue, Ludovica; Moja, Lorenzo
The emergence of severe acute respiratory syndrome (SARS) resulted in several outbreaks worldwide. Early tests for diagnosis were not always conclusive in identifying a SARS suspected patient. Nucleocapsid protein (NP) is the most predominant virus derived structural protein which is shed in high amounts in serum and nasopharyngeal aspirate during the first week of infection. As part of such efforts, a simple, easy to use immunoswab method was developed by generating a panel of monoclonal antibodies (MAbs), Bispecific MAbs and chicken polyclonal IgY antibody against the SARS-CoV nucleocapsid protein (NP). Employing the MAb-based immunoswab, an NP concentration of 200 pg/mL in saline and pig nasopharyngeal aspirate, and 500 pg/mL in rabbit serum were detected. BsMAb-based immunoswabs detected an NP concentration of 20 pg/mL in saline, 500 pg/mL in rabbit serum and 20–200 pg/mL in pig nasopharyngeal aspirate. Polyclonal IgY-based immunoswabs detected an NP concentration of 10 pg/mL in pig nasopharyngeal aspirate providing the most sensitive SARS point of care assay. Results show that the robust immunoswab method of detecting SARS-CoV NP antigen can be developed into an easy and effective way of identifying SARS suspected individuals during a future SARS epidemic, thereby reducing and containing the transmission. The key feature of this simple immunoswab diagnostic assay is its ability to detect the presence of the SARS-CoV antigen within 45–60 min with the availability of the body fluid samples.
Kammila, Sriram; Das, Dipankar; Bhatnagar, Pravin K.; Sunwoo, Hoon H.; Zayas-Zamora, Gustavo; King, Malcolm; Suresh, Mavanur R.
A cost-effective and highly sensitive portable diagnostic device is needed to enable much more widespread monitoring of health conditions in disease prevention, detection, and control. Miniaturized and easy-to-operate devices can reduce the inherent costs and inefficiencies associated with healthcare testing in central laboratories. Hence, clinicians are beginning to use point of care (POC) testing and flexible clinical chemistry testing devices which are beneficial for the patient. In our work, a low-cost and simple autonomous microfluidic device for biochemical detection was developed. The pumpless capillary system with capillary stop valves and trigger valves is fabricated on a silicon (Si) wafer and then bonded with the modified polydimethylsiloxane (PDMS) cover. The key point of this study is the change of the surface contact angle of the PDMS to achieve the functionalities such as timing features (capillary-driven stop valve) and basic logical functions (trigger valves). The polydimethylsiloxane-ethylene oxide polymer (PDMS-b-PEO) is utilized as a surfactant additive to make the PDMS hydrophilic. The contact angle of the modified PDMS can be adjusted from 80.9° to 21.5° with different mixing ratios. The contact angles of PEO-PDMS accepted in this work are from 80.9° to 58.5° to bring the capillary channel and valve into effect. This autonomous capillary-driven device with good microfluidic flow manipulation can be widely applied to a number of microfluidic devices and pumpless fluidic actuation mechanisms, which is suitable for cost-effective diagnostic tools in the biomedical analysis and POC testing applications. Another obstacle for miniaturization of the bio-detection system is the optical detector. We developed a novel, highly sensitive and miniaturized detector. It integrates a light source--light emitting diode (LED), all necessary optical components, and a photodiode with preamplifier into one package about 2 cm x 2 cm x 2 cm, especially for the applications of lab-on-a-chip (LOC), portable bio-detection system and POC diagnostic system. The size of this detector is smaller than the existing miniaturized detector of the size 5 cm x 5 cm x 5 cm. The fluorescence dye 5-Carboxyfluorescein (5-FAM) dissolved into the solvent DMSO (Dimethyl Sulfoxide) and diluted with DI water was used as the testing solution samples. The prototype has been tested to prove a remarkable sensitivity at pico-scale molar, around 1.08 pM, which is the highest sensitivity by now. It is higher than the current limit of detection at 1.96 nm, which will be presented in detail in the latter section.
ABSTRACTSpontaneous rectus sheath hematoma is an uncommon condition that can mimic other conditions associated with an acute abdomen. We report the case of a patient with a spontaneous rectus sheath hematoma due to a ruptured inferior epigastric artery pseudoaneurysm who presented with hypotension and severe abdominal pain and was diagnosed using emergency department point-of-care ultrasonography. Point-of-care ultrasonography has been increasingly used in the evaluation of emergency department patients with acute abdomen and hypotension to expedite the diagnosis and management of aortic aneurysm and intraperitoneal bleeding. Resuscitation and urgent surgical and interventional radiology consultations resulted in the successful embolization of a branch of the inferior epigastric artery and a good outcome. PMID:23458146
Shokoohi, Hamid; Boniface, Keith; Reza Taheri, M; Pourmand, Ali
In pediatric ankle injury, radiography is the current standard used to differentiate fracture from ligamentous injury; however, the associated cost, increased time, and radiation exposure pose a significant downside to this imaging modality. Point-of-care ultrasound may be an attractive alternative in this setting, as illustrated by this patient case. A 14-year-old boy presented to the emergency department with a left ankle inversion injury sustained while playing soccer. An emergency physician performed ultrasound examination that revealed findings consistent with a nondisplaced Salter-Harris I fracture of the distal fibula. The results of a formal radiograph confirmed this diagnosis. This case report presents the successful use of point-of-care ultrasound for detection of a Salter-Harris I ankle fracture, describes a stepwise approach for this new diagnostic technique in detail, and discusses its value in the setting of pediatric ankle injury. PMID:21855256
Taggart, Ian; Voskoboynik, Nika; Shah, Sachita; Liebmann, Otto
Current methods used to measure protein expression on microarrays, such as labeled fluorescent imaging, are not well suited for real-time, diagnostic measurements at the point of care. Studies have shown that microelectrical sensors utilizing silica nanowire, impedimetric, surface acoustic wave, magnetic nanoparticle and microantenna technologies have the potential to impact disease diagnosis by offering sensing characteristics that rival conventional sensing techniques. Their ability to transduce protein binding events into electrical signals may prove essential for the development of next-generation point-of-care devices for molecular diagnostics, where they could be easily integrated with microarray, microfluidic and telemetry technologies. However, common limitations associated with the microelectrical sensors, including problems with sensor fabrication and sensitivity, must first be resolved. This review describes governing technical concepts and provides examples demonstrating the use of various microelectrical sensors in the diagnosis of disease via protein biomarkers.
Arruda, David L; Wilson, William C; Nguyen, Crystal; Yao, Qi W; Caiazzo, Robert J; Talpasanu, Ilie; Dow, Douglas E; Liu, Brian C-S
Case 1 involved a 24-year-old man who complained of severe right groin pain and difficulty of walking after falling to the\\u000a ground while snowboarding. The patient manifested flexion hip contracture on the right side. Abdominal examination detected\\u000a tenderness in the right lower quadrant. Point-of-care ultrasound identified swelling of the right psoas major, compressing\\u000a the right kidney. Case 2 involved a
Toru Kameda; Masato Fujita; Isao Takahashi
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.
Collecting clinical data directly from clinicians is a challenge. Many standard development environments designed to expedite the creation of user interfaces for electronic healthcare applications do not provide acceptable components for satisfying the requirements for collecting and displaying clinical data at the point of care on the tablet computer. Through an iterative design and testing approach using think-aloud sessions in the eye care setting, we were able to identify and resolve several user interface issues. Issues that we discovered and subsequently resolved included checkboxes that were too small to be selectable with a stylus, radio buttons that could not be unselected, and font sizes that were too small to be read at arm's length. PMID:17238715
Silvey, Garry M; Lobach, David F; Macri, Jennifer M; Hunt, Megan; Kacmaz, Roje O; Lee, Paul P
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 48 hours were included. Because the reference laboratory delivers glucose values after approximately 30 to 60 minutes, which is too slow to use in a glucose regulation protocol and for calibration of the subcutaneous continuous glucose monitoring system (CGMS) (CGMS System Gold), we first validated the ICU-based blood gas/glucose analyser ABL715 (part 1 of the study). Subsequently, part 2 was performed: after inserting (and calibrating) the subcutaneous CGMS, heparinised arterial blood samples were drawn from an arterial line every 6 hours and analysed on both the Precision PCx point-of-care meter using test strips and on the blood gas/glucose analyser ABL715. CGMS glucose data were downloaded after 24 to 72 hours. The results of the paired measurements were analysed as a scatter plot by the method of Bland and Altman and were expressed as a correlation coefficient. Results Part 1: Four hundred and twenty-four blood samples were drawn from 45 critically ill ICU patients. The ICU-based blood gas/glucose analyser ABL715 provided a good estimate of conventional laboratory glucose assessment: the correlation coefficient was 0.95. In the Clarke error grid, 96.8% of the paired measurements were in the clinically acceptable zones A and B. Part 2: One hundred sixty-five paired samples were drawn from 19 ICU patients. The Precision PCx point-of-care meter showed a correlation coefficient of 0.89. Ninety-eight point seven percent of measurements were within zones A and B. The correlation coefficient for the subcutaneous CGMS System Gold was 0.89. One hundred percent of measurements were within zones A and B. Conclusion The ICU-based blood glucose analyser ABL715 is a rapid and accurate alternative for laboratory glucose determination and can serve as a standard for ICU blood glucose measurements. The Precision PCx is a good alternative, but feasibility may be limited because of the blood sample handling. The subcutaneous CGMS System Gold is promising, but real-time glucose level reporting is necessary before it can be of clinical use in the ICU. When implementing a glucose-insulin algorithm in patient care or research, one should realise that the absolute glucose level may differ systematically among various measuring methods, influencing targeted glucose levels.
Corstjens, Anouk M; Ligtenberg, Jack JM; van der Horst, Iwan CC; Spanjersberg, Rob; Lind, Joline SW; Tulleken, Jaap E; Meertens, John HJM; Zijlstra, Jan G
The measurement of natriuretic peptides (NPs), B-type NP or N-terminal pro-B-type NP, can be an important tool in the diagnosis of acute heart failure in patients presenting to an Emergency Department (ED) with acute dyspnea, according to international guidelines. Studies and subsequent meta-analyses are mixed on the absolute value of routine NP assessment of ED patients. However, levels of NPs are likely to be used also to guide treatment and to assess risk of adverse outcomes in other patients at risk of developing heart failure, including those with pulmonary embolism or diabetes, or receiving chemotherapy. Natriuretic peptide levels, like other biomarkers, can now be measured at the point of care (POC). We have reviewed the current status of NP measurement together with the potential contribution of POC measurement of NPs to clinical care delivery in the emergency and other settings. Several POC systems for measuring NP levels are now available: these produce test results within 15 minutes and appear sufficiently sensitive and robust to be used routinely in diagnostic evaluations. Point-of-care systems could be used to assess NP levels in the ED and community outpatient settings to monitor the risk of acute heart failure. Furthermore, the use of protocol-driven POC testing of NP within the time frame of a patient consultation in the ED may facilitate and accelerate the throughput and disposition of at-risk patients. Appropriately designed clinical trials will be needed to confirm these potential benefits. It is also important that processes of care delivery are redesigned to take full advantage of the faster turnaround times provided by POC technology. PMID:24093839
Bingisser, Roland; Cairns, Charles B; Christ, Michael; Collinson, Paul; Hausfater, Pierre; Lindahl, Bertil; Mair, Johannes; Price, Christopher; Venge, Per
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
Objective To evaluate the ability of international point of care information summaries to update evidence relevant to medical practice. Design Prospective cohort bibliometric analysis. Setting Top five point of care information summaries (Clinical Evidence, EBMGuidelines, eMedicine, Dynamed, UpToDate) ranked for coverage of medical conditions, editorial quality, and evidence based methodology. Main outcome measures From June 2009 to May 2010 we measured the incidence of research findings relating to potentially eligible newsworthy evidence. As samples, we chose systematic reviews rated as relevant by international research networks (such as, Evidence-Based Medicine, ACP Journal Club, and the Cochrane Collaboration). Every month we assessed whether each sampled review was cited in at least one chapter of the five summaries. The cumulative updating rate was analysed with Kaplan-Meier curves. Results From April to December 2009, 128 reviews were retrieved; 53% (68) from the literature surveillance journals and 47% (60) from the Cochrane Library. At nine months, Dynamed had cited 87% of the sampled reviews, while the other summaries had cited less than 50%. The updating speed of Dynamed clearly led the others. For instance, the hazard ratios for citations in EBM Guidelines and Clinical Evidence versus the top performer were 0.22 (95% confidence interval 0.17 to 0.29) and 0.03 (0.01 to 0.05). Conclusions Point of care information summaries include evidence relevant to practice at different speeds. A qualitative analysis of updating mechanisms is needed to determine whether greater speed corresponds to more appropriate incorporation of new information.
One of the most exciting applications of microfluidics-based diagnostics is its potential use in next generation point-of-care (POC) devices. Many prototypes are already in existence, but, as of yet, few have achieved commercialisation. In this article, we consider the issue surrounding product qualification as a potential barrier to market success. The study discusses, in the context of POC microfluidics-based diagnostics, what the generic issues are and potential solutions. Our findings underline the need for a community-based effort that is necessary to speed up the product qualification process. PMID:23652789
Tantra, Ratna; van Heeren, Henne
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
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
The use of point-of-care blood gas analyzers in cardiac surgery has been on the increase over the past decade. The availability of these analyzers in the operating room and post-operative intensive care units eliminates the time delays to transport samples to the main laboratory and reduces the amount of blood sampled to measure such parameters as electrolytes, blood gases, lactates, glucose and hemoglobin/hematocrit. Point-of-care analyzers also lead to faster and more reliable clinical decisions while the patient is still on the heart lung machine. Point-of-care devices were designed to provide safe, appropriate and consistent care of those patients in need of rapid acid/base balance and electrolyte management in the clinical setting. As a result, clinicians rely on their values to make decisions regarding ventilation, acid/base management, transfusion and glucose management. Therefore, accuracy and reliability are an absolute must for these bedside analyzers in both the cardiac operating room and the post-op intensive care units. Clinicians have a choice of two types of technology to measure hemoglobin/hematocrit during bypass, which subsequently determines their patient's level of hemodilution, as well as their transfusion threshold. All modern point-of-care blood gas analyzers measure hematocrit using a technology called conductivity, while other similar devices measure hemoglobin using a technology called co-oximetry. The two methods are analyzed and compared in this review. The literature indicates that using conductivity to measure hematocrit during and after cardiac surgery could produce inaccurate results when hematocrits are less than 30%, and, therefore, result in unnecessary homologous red cell transfusions in some patients. These inaccuracies are influenced by several factors that are common and unique to cardiopulmonary bypass, and will also be reviewed here. It appears that the only accurate, consistent and reliable method to determine hemodilution and establish transfusion thresholds based on nadir hematocrits during cardiopulmonary bypass, and immediately post cardiac surgery, is with the use of co-oximetry. PMID:18018397
Myers, Gerard J; Browne, Joe
Stakeholders agree that supporting high-quality diagnostics is essential if we are to continue to make strides in the fight against human immunodeficiency virus (HIV) and tuberculosis. Despite the need to strengthen existing laboratory infrastructure, which includes expanding and developing new laboratories, there are clear diagnostic needs where conventional laboratory support is insufficient. Regarding HIV, rapid point-of-care (POC) testing for initial HIV diagnosis has been successful, but several needs remain. For tuberculosis, several new diagnostic tests have recently been endorsed by the World Health Organization, but a POC test remains elusive. Human immunodeficiency virus and tuberculosis are coendemic in many high prevalence locations, making parallel diagnosis of these conditions an important consideration. Despite its clear advantages, POC testing has important limitations, and laboratory-based testing will continue to be an important component of future diagnostic networks. Ideally, a strategic deployment plan should be used to define where and how POC technologies can be most efficiently and cost effectively integrated into diagnostic algorithms and existing test networks prior to widespread scale-up. In this fashion, the global community can best harness the tremendous capacity of novel diagnostics in fighting these 2 scourges. PMID:22457286
Schito, Marco; Peter, Trevor F; Cavanaugh, Sean; Piatek, Amy S; Young, Gloria J; Alexander, Heather; Coggin, William; Domingo, Gonzalo J; Ellenberger, Dennis; Ermantraut, Eugen; Jani, Ilesh V; Katamba, Achilles; Palamountain, Kara M; Essajee, Shaffiq; Dowdy, David W
Background Recruitment of hard-to-reach ethnic minorities such as Korean Americans (KAs) requires substantial time, cost, and strategic effort. A point-of-care (POC) A1c test could facilitate the recruitment of such populations for diabetes research in community settings. Methods A two-step approach for participant screening was employed: Potential participants were first screened using the POC A1c test at a community location. Only those with POC A1c levels ?7.5% were referred for a confirmatory lab test within two weeks. Results In total, 237 KAs were screened using the POC A1c test; 92 were referred for confirmatory testing and 83 who got the laboratory A1c measurement were confirmed eligible (A1c ?7.5%). There was a strong positive correlation between the POC and reference laboratory measurements (?=0.83, p<.001). Conclusion Using a POC A1c method as a front-line screening test can facilitate the recruitment of KAs with type 2 diabetes, while saving cost, time, and effort.
Nam, Soohyun; Han, Hae-Ra; Song, Hee-Jung; Song, Yongshin; Kim, Kim B.; Kim, Miyong T.
Patients with acute Achilles tendon injuries from sport related activities are frequently seen in the emergency department (ED). Missed or delayed diagnosis of an Achilles tendon rupture can result in significant patient morbidity. However, the diagnosis of an Achilles tendon rupture is not always clear clinically. Physical examination maneuvers to assess for a tendon injury can be limited by pain and soft tissue swelling. Ultrasound has been shown to be very sensitive in detecting an Achilles tendon rupture.We report a case of a 39-year-old woman who presented to the ED with severe left ankle and leg pain. Her physical examination was limited by pain. However, a point-of-care ultrasound examination helped in making a prompt and accurate diagnosis of acute Achilles tendon rupture. This case demonstrates that point-of-care ultrasound can be a useful diagnostic tool in the assessment of patients with suspected Achilles tendon rupture, particularly when the physical examination is limited. PMID:21406322
Adhikari, Srikar; Marx, Jared; Crum, Todd
Objective To 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. Design A 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 time to clinical questions arising at the point of care. Measurements All transactions were stored by an intermediate server. Evaluators recorded clinical scenarios and questions, identified MEDLINE citations that answered the questions, and submitted daily and summative reports of their experience. A senior medical librarian corroborated the relevance of the selected citation to each scenario and question. Results Evaluators answered 68% of 363 background and foreground clinical questions during rounding sessions using a variety of MD on Tap features in an average session length of less than four minutes. The evaluator, the number and quality of query terms, the total number of citations found for a query, and the use of auto-spellcheck significantly contributed to the probability of query success. Conclusion Handheld computers with Internet access are useful tools for healthcare providers to access MEDLINE in real time. MEDLINE citations can answer specific clinical questions when several medical terms are used to form a query. The MD on Tap application is an effective interface to MEDLINE in clinical settings, allowing clinicians to quickly find relevant citations.
Hauser, Susan E.; Demner-Fushman, Dina; Jacobs, Joshua L.; Humphrey, Susanne M.; Ford, Glenn; Thoma, George R.
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
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
We report that use of the popular analgesic tramadol can cause false-positive urine buprenorphine results. We examined the extent of tramadol cross-reactivity in three point-of-care urine buprenorphine immunoassays (ACON, QuikStrip, and ABMC) and an instrument-based one (Cedia). We tested 29 urine samples from patients known to be taking tramadol. Ten different samples tested positive for urine buprenorphine by at least one immunoassay. Samples with positive buprenorphine screens by immunoassay were tested for total buprenorphine and total norbuprenorphine content by liquid chromatography-tandem mass spectrometry (LC-MS-MS), which confirmed that seven of the 10 positive samples were false-positives. The remaining three positive immunoassay samples had insufficient quantity for LC-MS-MS testing. No false-positives were detected with the ACON (10 ng/mL calibration cutoff) or the Cedia assay (using a 20 ng/mL calibration cutoff). All four false-positive Cedia results (using a 5 ng/mL cutoff) in this study tested negative using the ACON device. Our data suggest that tramadol use can cause false-positive urine buprenorphine immunoassays, and this effect appears to be assay-dependent. Tramadol interference with the Cedia assay is clinically relevant, especially if the 5 ng/mL calibration cutoff is used. PMID:18544218
Shaikh, Salima; Hull, Mindy J; Bishop, Kenneth A; Griggs, David A; Long, William H; Nixon, Andrea L; Flood, James G
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.
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
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
In medical facilities, there is strong motivation to develop detection systems that can provide continuous analysis of fluids in medical tubing used to either deliver or remove fluids from a patient's body. Possible applications include systems that increase the safety of intravenous (IV) drug injection and point-of-care health monitoring. In this work, we incorporated a surface-enhanced Raman scattering (SERS) sensor comprised of an array of closely spaced metal nanodomes into flexible tubing commonly used for IV drug delivery and urinary catheters. The nanodome sensor was fabricated by a low-cost, large-area process that enables single use disposable operation. As exemplary demonstrations, the sensor was used to kinetically detect promethazine (pain medication) and urea (urinary metabolite) within their clinically relevant concentration ranges. Distinct SERS peaks for each analyte were used to demonstrate separate detection and co-detection of the analytes. PMID:22159459
Choi, Charles J; Wu, Hsin-Yu; George, Sherine; Weyhenmeyer, Jonathan; Cunningham, Brian T
Recent concerns about the quality and safety of healthcare practice provide an imperative for discovering and accessing learning resources. The growing ubiquity of the Internet, World Wide Web, and on-line educational content provide opportunity for healthcare practitioners to identify and master learning in a granular and rapid fashion. The e-learning community at large has developed a number of standards to facilitate interoperability of learner competencies, metadata describing on-line content, and packaging and navigation of such content. The overall goal of our project is to enable healthcare professionals to easily and rapidly discover learning content at the point of care. This discovery and access of learning content will be based on healthcare-specific extensions of existing e-learning standards, which are themselves based on other Web standards, such as Web Services.
Hersh, William R.; Bhupatiraju, Ravi Teja; Greene, Peter S.; Smothers, Valerie; Cohen, Cheryl
Although advanced fluid handling using elastomeric valves is useful for a variety of lab-on-a-chip procedures, their operation has traditionally relied on external laboratory infrastructure (such as gas tanks, computers, and ground electricity). This dependence has held back the use of elastomeric microvalves for point-of-care settings. Here, we demonstrate that microfabricated microvalves, via liquid-filled control channels, can be actuated using only a handheld instrument powered by a 9 V battery. This setup can achieve on-off fluid control with fast response times, coordinated switching of multiple valves, and operation of a biological assay. In the future, this technique may enable the widely used elastomeric microvalves (made by multilayer soft lithography) to be increasingly adopted for portable sensors and lab-on-a-chip systems. PMID:20383403
Addae-Mensah, Kweku A; Cheung, Yuk Kee; Fekete, Veronika; Rendely, Matthew S; Sia, Samuel K
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
Acute traumatic posterior shoulder dislocations are rare. The diagnosis is often missed or delayed, as radiologic abnormalities can be subtle. We report a case of a 37-year-old man who presented to the emergency department with severe right shoulder pain and inability to move his arm after a motor vehicle collision. Based on examination, he was initially thought to have an anterior dislocation; however, point-of-care (POC) ultrasound clearly demonstrated a posterior shoulder dislocation. Real-time ultrasound-guided intra-articular local anesthetic injection facilitated closed reduction in the emergency department without procedural sedation, and POC ultrasound confirmed successful reduction at the bedside after the procedure. This case demonstrates that POC ultrasound can be a useful diagnostic tool in the rapid assessment and treatment for patients with suspected posterior shoulder dislocation. PMID:22944540
Beck, Sierra; Chilstrom, Mikaela
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.
Objectives We implemented a curriculum using self-directed learning plans (SDLPs) based on clinical questions arising from the residents' practice, and we report on perceptions and attitudes from residents in internal medicine regarding the use of SDLPs conceived at point of care. Methods Internal medicine residents at a single community hospital in the Midwest were surveyed in 2006 regarding SDLPs. We report their perceived effectiveness in identifying knowledge gaps, the processes used to fill those gaps, and the resident outcomes using descriptive statistics. Results A total of 26 out of 37 residents (70%) responded. Most (24 of 26; 92%) perceived SDLPs helped them to identify and fill knowledge gaps and that their skills in framing questions (23 of 26; 88%), identifying resources (21 of 26; 81%), and critically appraising the evidence (20 of 26; 77%) improved through regular use. They also felt these plans led to a meaningful change in their practice or provided further direction for learning (17 of 26; 65%). Most (21 of 26; 81%) reported their intent to include point-of-care learning in their continuing education after residency. We found no significant differences in the responses of first-year compared with second- or third-year residents. Conclusions Questions arising during patient care are strong motivators for physician self-directed learning. The residents' responses indicated that they accepted the SDLPs and intend to use them in practice. Embedding the discussion of the SDLPs in preclinic conferences has ensured sustainability during the past 5 years and has enabled us to demonstrate teaching of practice-based learning and improvement.
Smith, Susan J; Kakarala, Radhika R; Talluri, Siva K; Sud, Parul; Parboosingh, J
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
Background Chlamydia trachomatis (Ct) is the most common cause of bacterial sexually transmitted diseases (STD) worldwide. While commercial nucleic acid amplification tests (NAAT) are available for Ct, none are rapid or inexpensive enough to be used at the point-of-care (POC). Towards the first Ct POC NAAT, we developed a microfluidic assay that simultaneously interrogates nine Ct loci in 20 minutes. Methodology and Principal Findings Endocervical samples were selected from 263 women at high risk for Ct STDs (?35% prevalence). A head-to-head comparison was performed with the Roche-Amplicor NAAT. 129 (49.0%) and 88 (33.5%) samples were positive by multiplex and Amplicor assays, respectively. Sequencing resolved 71 discrepant samples, confirming 53 of 53 positive multiplex samples and 12 of 18 positive Amplicor samples. The sensitivity and specificity were 91.5% and 100%, and 62.4% and 95.9%, respectively, for multiplex and Amplicor assays. Positive and negative predictive values were 100% and 91%, and 94.1% and 68.6%, respectively. Conclusions This is the first rapid multiplex approach to Ct detection, and the assay was also found to be superior to a commercial NAAT. In effect, nine simultaneous reactions significantly increased sensitivity and specificity. Our assay can potentially increase Ct detection in globally diverse clinical settings at the POC.
Dean, Deborah; Turingan, Rosemary S.; Thomann, Hans-Ulrich; Zolotova, Anna; Rothschild, James; Joseph, Sandeep J.; Read, Timothy D.; Tan, Eugene; Selden, Richard F.
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
Frontline managers in health care are the keepers of culture, the gateway to evoking a grass roots intelligence network, and they hold a pivotal role in advancing innovation at the point of care. Their roles are ever expanding and include knowledge and skills in managing the business, leading the people, and advancing their own leadership development. In all 3 areas, the impact of their leadership exponentially increases if they maximize innovative thinking and action. Health care executives need to establish the expectations for an innovative culture and the role of frontline managers. They must model the behaviors they promote and take the time to develop these frontline managers who are the hub for innovative success in the organization. This article offers insights and practical applications while exploring the innovation keystones of the following: creating an organizational culture of innovation, igniting collaboration that fuels diverse thinking and creativity, utilizing meaningful data to drive innovative decisions, and assessing and monitoring the ongoing climate and outcomes of innovation. PMID:23222751
Shiparski, Laurie; Authier, Philip
The vision for the Clinical Nurse Leader CNL(R) role began in 2003-2004 in response to the Institute of Medicine's quality and safety reports. The CNL was envisioned as a nurse who would provide direct clinical leadership at the point of care, working to insure that care delivery is safe, evidence-based, and targeted towards optimal quality outcomes for the cohort of clients served by the CNL. In this article the authors describe the background and intent of the CNL role and explain how the CNL is prepared to facilitate a culture of safety and to enhance safety of the care provided for a group of patients. They illustrate how the CNL enhances safety across diverse settings and conclude by noting the power that CNLs have for building continuing coalitions of safety. The value of the CNL as a front-line care leader for building and sustaining safer and higher quality care delivery environments for the future is highlighted. PMID:22324570
Reid, Kathryn B; Dennison, Pamela
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
A new generation of programmable diagnostic devices is needed to take advantage of information generated from the study of genomics, proteomics, metabolomics and glycomics. This report describes the ‘programmable nano-bio-chip’ with potential to bridge the significant scientific, technology and clinical gaps through the creation of a diagnostic platform to measure the molecules of life. This approach, with results at the point-of-care, possesses capabilities for measuring such diverse analyte classes as cells, proteins, DNA and small molecules in the same compact device. Applications such as disease diagnosis and prognosis for areas including cancer, heart disease and HIV are described. New diagnostic panels are inserted as ‘plug and play’ elements into the modular platform with universal assay operating systems and standard read out sequences. The nano-bio-chip ensemble exhibits excellent analytical performance and cost-effectiveness with extensive validation versus standard reference methods (R2 = 0.95–0.99). This report describes the construction and use of two major classes of nano-bio-chip designs that serve as cellular and chemical processing units, and provides perspective on future growth in this newly emerging field of programmable nano-bio-chip sensor systems.
Jokerst, Jesse V
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. PMID:23020427
Peng, Weng Kung; Chen, Lan; Han, Jongyoon
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.
Steady state diffuse reflectance spectroscopy is a nondestructive method for obtaining biochemical and physiological information from skin tissue. In medical conditions such as neonatal jaundice excess bilirubin in the blood stream diffuses into the surrounding tissue leading to a yellowing of the skin. Diffuse reflectance measurement of the skin tissue can provide real time assessment of the progression of a disease or a medical condition. Here we present a noninvasive point-of-care system that utilizes diffuse reflectance spectroscopy to quantifying bilirubin from skin reflectance spectra. The device consists of an optical system integrated with a signal processing algorithm. The device is then used as a platform to study two different spectral databases. The first spectral database is a jaundice animal model in which the jaundice reflectance spectra are synthesized from normal skin. The second spectral database is the spectral measurements collected on human volunteers to quantify the different chromophores and other physical properties of the tissue such as Hematocrit, Hemoglobin, etc. The initial trials from each of these spectral databases have laid the foundation to verify the performance of this bilirubin quantification device. PMID:21095858
Alla, Suresh K; Huddle, Adam; Butler, Joshua D; Bowman, Peggy S; Clark, Joseph F; Beyette, Fred R
Point-of-care (POC) genetic diagnostics critically depends on miniaturization and integration of sample processing, nucleic acid amplification, and detection systems. Polymerase chain reaction (PCR) assays have extensively applied for the diagnosis of genetic markers of disease. Microfluidic chips for microPCR with different materials and designs have been reported. Temperature cycling systems with varying thermal masses and conductivities, thermal cycling times, flow-rates, and cross-sectional areas, have also been developed to reduce the nucleic acid amplification time. Similarly, isothermal amplification techniques (e.g., loop-mediated isothermal amplification or LAMP), which are still are emerging, have a better potential as an alternative to PCR for POC diagnostics. Isothermal amplification techniques have: (i) moderate incubation temperature leading to simplified heating and low power consumption, (ii) yield high amount of amplification products, which can be detected either visually or by simple detectors, (iii) allow direct genetic amplification from bacterial cells due to the superior tolerance to substances that typically inhibit PCR, (iv) have high specificity, and sensitivity, and (v) result in rapid detection often within 10-20 min. The aim of this review is to provide a better understanding of the advantages and limitations of microPCR and microLAMP systems for rapid and POC diagnostics. PMID:22704369
Ahmad, Farhan; Hashsham, Syed A
Measurement of the glomerular filtration rate (GFR) is the gold standard for precise assessment of kidney function. A rapid, point-of-care determination of the GFR may provide advantages in the clinical setting over currently available assays. Here we demonstrate a proof of principle for such an approach in a pig and dogs, two species that approximate the vascular access and GFR
Exing Wang; Daniel J Meier; Ruben M Sandoval; Vanessa E Von Hendy-Willson; Barrak M Pressler; Robert M Bunch; Mouhamad Alloosh; Michael S Sturek; George J Schwartz; Bruce A Molitoris
Background: The management of critically ill infants and neonates includes frequent determination of arte- rial blood gas, electrolyte, and hematocrit values. An objective of attached point-of-care patient monitoring is to provide clinically relevant data without the adverse consequences associated with serial phlebotomy. Methods: We prospectively determined the mean dif- ference (and SD of the difference) from laboratory methods of an
Glenn F. Billman; Amy B. Hughes; Golde G. Dudell; Elizabeth Waldman; Lisa M. Adcock; Edmund N. Orsini; Adolph J. Koska; Linda J. Van Marter; Neil N. Finer; Jeff C. Kulhavy; Ronald D. Feld; John A. Widness
Atlas Genetics has developed a Point-of-Care device for Chlamydia trachomatis utilizing a novel electrochemical detection principle. The assay has a time-to-result of less than 25 minutes. An independent pre-clinical validation study using 306 pre-typed clinical samples determined a clinical sensitivity of 98.1% and specificity of 98.0%.
Shenton, Daniel P.; Holden, Jeffrey; Gaydos, Charlotte A.
Integrating knowledge-based resources at the point of care is an important opportunity for hospital library involvement. In the progression of an IAIMS planning grant, the digital library is recognized as pivotal to the success of information domain integration throughout the institution. The planning process, data collection, and evolution of the planning project are discussed. PMID:18844088
Schwartz, Linda Matula; Iobst, Barbara
Background Point-of-care devices (POCDs) for monitoring long-term oral anticoagulation therapy (OAT) may be a useful alternative to laboratory-based international normalized ratio [INR] testing and clinical management. Purpose To determine clinical outcomes of the use of POCDs for OAT management by performing a meta-analysis. Previous meta-analyses on POCDs have serious limitations. Data sources PubMed, the Cochrane Library, DIALOG, MEDLINE, EMBASE, BIOSIS Previews and PASCAL databases. Study selection Randomized controlled trials of patients on long-term OAT, comparing anticoagulation monitoring by POCD with laboratory INR testing and clinical management. Data extraction 1) rates of major hemorrhage; 2) rates of major thromboembolic events; 3) percentage of time that the patient is maintained within the therapeutic range; 4) deaths. Outcomes were compared using a random-effects model. Summary measures of rates were determined. The quality of studies was assessed using the Jadad scale. Data synthesis Seventeen articles (16 studies) were included. Data analysis showed that POCD INR testing reduced the risk of major thromboembolic events (odds ratio [OR] = 0.51; 95% confidence interval [CI] 0.35–0.74), was associated with fewer deaths (OR = 0.58; 95% CI = 0.38–0.89), and resulted in better INR control compared with laboratory INR testing. No significant difference between the two management modalities with respect to odds ratios for major hemorrhage was found. Limitations Quality scores varied from 1 to 3 (out of a maximum of 5). Only 3 studies defined how thromboembolic events would be diagnosed, casting doubt on the accuracy of the reporting of thromboembolic events. The studies suggest that only 24% of patients are good candidates for self-testing and self-management. Compared with patients managed with laboratory-based monitoring, POCD patients underwent INR testing at a much higher frequency and received much more intensive education on OAT management. Conclusions The use of POCDs is safe and may be more effective than laboratory-based monitoring. However, most patients are not good candidates for self-testing and self-management. Patient education and frequency of testing may be the most important factors in successful PODC management. Definitive conclusions about the clinical benefits provided by self-testing and self-management require more rigorously designed trials.
Wells, Philip S; Brown, Allan; Jaffey, James; McGahan, Lynda; Poon, Man-Chiu; Cimon, Karen
Industry rely a lot on vision for in line or off line quality inspection. Whereas most of these applications use 2D vision, the need for 3D vision is increasing. Optical Coherence Tomography (OCT) is widely used in medical application to obtain 3D images of biological tissues but is still limited to low-speed and high price instruments in industrial applications. We developed a CMOS camera specially designed for parallel OCT (p-OCT). The advantage of this method over other OCT techniques is its high speed and its ability to maintain a high lateral resolution over large measurement depths. Our camera can acquire up to one million 2D images per second. The amplitude and phase of the modulated signal is calculated within every pixel. Up to 10'000 such amplitude and phase results can be returned in a second, for every pixel. We will present our instrument, which includes a rugged and compact interferometer aligned with a robotized assembly technique. This imaging interferometer is scanned during acquisition, allowing to maintain a high lateral resolution (typically 2 micron) over several millimeters. The interferometer is easily interchangeable (snap-in magnets) in order to choose the ideal magnification for the application. This compact and versatile system can be built directly on a robot arm or scanned over large objects.
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 2min, 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 10ng/ml in 2min. 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
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.
Improvement of prehospital triage is essential to ensure rapid management of patients with acute myocardial infarction (AMI). This study evaluates the feasibility of prehospital quantitative point-of-care cardiac troponin T (POC-cTnT) analysis, its ability to identify patients with AMI, and its capacity to predict mortality. The study was performed in the Central Denmark Region from May 2010 to May 2011. As a supplement to electrocardiography, a prehospital POC-cTnT measurement was performed by a paramedic in patients with suspected AMI. AMI was diagnosed according to the universal definition of myocardial infarction using the ninety-ninth percentile upper reference level as diagnostic cut point. The paramedics performed POC-cTnT measurements in 985 subjects with a symptom duration of 70 minutes (95% CI, 35 to 180); of whom, 200 (20%) had an AMI. The prehospital sample was obtained 88 minutes (range, 58 to 131) before the sample made on admission to the hospital. The sensitivity for detection of patients with an AMI was 39% (95% CI, 32% to 46%) and the diagnostic accuracy of the POC-cTnT values was 0.67 (95% CI, 0.64 to 0.71). Adjusted survival analysis showed a strong significant association between elevated prehospital POC-cTnT level above the detection level of 50 ng/L and mortality in patients with a suspected AMI irrespective of whether an AMI was diagnosed. In conclusion, large-scale quantitative prehospital POC-cTnT testing by paramedics is feasible. An elevated prehospital POC-cTnT value contains diagnostic information and is highly predictive of mortality in patients with a suspected AMI. PMID:23953697
Stengaard, Carsten; Sørensen, Jacob Thorsted; Ladefoged, Søren Andreas; Christensen, Erika Frischknecht; Lassen, Jens Flensted; Bøtker, Hans Erik; Terkelsen, Christian Juhl; Thygesen, Kristian
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.
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.
Introduction Early initiation of antiretroviral therapy (ART) in eligible pregnant women is a key intervention for prevention of mother-to-child transmission (PMTCT) of HIV. However, in many settings in sub-Saharan Africa where ART-eligibility is determined by CD4 cell counts, limited access to laboratories presents a significant barrier to rapid ART initiation. Point-of-care (POC) CD4 cell count testing has been suggested as one approach to overcome this challenge, but there are few data on the agreement between POC CD4 cell enumeration and standard laboratory-based testing. Methods Working in a large antenatal clinic in Cape Town, South Africa, we compared POC CD4 cell enumeration (using the Alere PimaTM Analyzer) to laboratory-based flow cytometry in consecutive HIV-positive pregnant women. Bland–Altman methods were used to compare the two methods, including analyses by subgroups of participant gestational age. Results Among the 521 women participating, the median gestational age was 23 weeks, and the median CD4 cell count according to POC and laboratory-based methods was 388 and 402 cells/µL, respectively. On average, the Pima POC test underestimated CD4 cell count relative to flow cytometry: the mean difference (laboratory test minus Pima POC) was 22.7 cells/µL (95% CI, 16.1 to 29.2), and the limits of agreement were ?129.2 to 174.6 cells/µL. When analysed by gestational age categories, there was a trend towards increasing differences between laboratory and POC testing with increasing gestational age; in women more than 36 weeks’ gestation, the mean difference was 45.0 cells/µL (p=0.04). Discussion These data suggest reasonable overall agreement between Pima POC CD4 testing and laboratory-based flow cytometry among HIV-positive pregnant women. The finding for decreasing agreement with increasing gestational age requires further investigation, as does the operational role of POC CD4 testing to increase access to ART within PMTCT programmes.
Myer, Landon; Daskilewicz, Kristen; McIntyre, James; Bekker, Linda-Gail
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
Technology advances in rapid diagnosis and clinical monitoring of human immunodeficiency virus (HIV) infection have been made in recent years, greatly benefiting those at risk of HIV infection, those needing care and treatment, and those on antiretroviral (ART) therapy in sub-Saharan Africa. However, resource-limited, geographically remote, and harsh climate regions lack uniform access to these technologies. HIV rapid diagnostic tests (RDTs) and monitoring tools, such as those for CD4 counts, as well as tests for coinfections, are being developed and have great promise in these settings to aid in patient care. Here we explore the advances in point-of-care (POC) technology in the era where portable devices are bringing the laboratory to the patient. Quality management approaches will be imperative for the successful implementation of POC testing in endemic settings to improve patient care. PMID:22287974
Shott, Joseph P; Galiwango, Ronald M; Reynolds, Steven J
Technology advances in rapid diagnosis and clinical monitoring of human immunodeficiency virus (HIV) infection have been made in recent years, greatly benefiting those at risk of HIV infection, those needing care and treatment, and those on antiretroviral (ART) therapy in sub-Saharan Africa. However, resource-limited, geographically remote, and harsh climate regions lack uniform access to these technologies. HIV rapid diagnostic tests (RDTs) and monitoring tools, such as those for CD4 counts, as well as tests for coinfections, are being developed and have great promise in these settings to aid in patient care. Here we explore the advances in point-of-care (POC) technology in the era where portable devices are bringing the laboratory to the patient. Quality management approaches will be imperative for the successful implementation of POC testing in endemic settings to improve patient care.
Shott, Joseph P.; Galiwango, Ronald M.; Reynolds, Steven J.
Background Point-of-care (POC) products are widely used as information reference tools in the clinical setting. Although usability, scope of coverage, ability to answer clinical questions, and impact on health outcomes have been studied, no comparative analysis of the characteristics of the references, the evidence for the content, in POC products is available. Objective The objective of this study was to compare the type of evidence behind five POC clinical information products. Methods This study is a comparative bibliometric analysis of references cited in monographs in POC products. Five commonly used products served as subjects for the study: ACP PIER, Clinical Evidence, DynaMed, FirstCONSULT, and UpToDate. The four clinical topics examined to identify content in the products were asthma, hypertension, hyperlipidemia, and carbon monoxide poisoning. Four indicators were measured: distribution of citations, type of evidence, product currency, and citation overlap. The type of evidence was determined based primarily on the publication type found in the MEDLINE bibliographic record, as well as the Medical Subject Headings (MeSH), both assigned by the US National Library of Medicine. MeSH is the controlled vocabulary used for indexing articles in MEDLINE/PubMed. Results FirstCONSULT had the greatest proportion of references with higher levels of evidence publication types such as systematic review and randomized controlled trial (137/153, 89.5%), although it contained the lowest total number of references (153/2330, 6.6%). DynaMed had the largest total number of references (1131/2330, 48.5%) and the largest proportion of current (2007-2009) references (170/1131, 15%). The distribution of references cited for each topic varied between products. For example, asthma had the most references listed in DynaMed, Clinical Evidence, and FirstCONSULT, while hypertension had the most references in UpToDate and ACP PIER. An unexpected finding was that the rate of citation overlap was less than 1% for each topic across all five products. Conclusions Differences between POC products are revealed by examining the references cited in the monographs themselves. Citation analysis extended to include key content indicators can be used to compare the evidence levels of the literature supporting the content found in POC products.
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
In this prospective, controlled study we compared the ability of anesthesia residents to diagnose and treat a simulated malignant hyperthermia (MH) scenario with and without the ability to use the On-Line Electronic Help (OLEH) information system or any other written guidelines. The OLEH is a point-of-care information system for the anesthesia provider in the operating room. The score for MH treatment after diagnosis based on clinical actions was significantly higher (P = 0.018) in the OLEH-user group (21.5 +/- 4.9) compared with a control group (15.5 +/- 7.6). This study demonstrates the possible value of a point-of-care information system in patient care; however, the significance of the results may be limited by the participants' anticipation of an acute event during training requiring the use of the OLEH. PMID:16428555
Berkenstadt, Haim; Yusim, Yakov; Ziv, Amitai; Ezri, Tiberiu; Perel, Azriel
A point-of-care system for continuous health monitoring should be wearable, easy to use, and affordable to promote patient independence and facilitate acceptance of new home healthcare technology. Reconfigurability, interoperability, and scalability are important. Standardization supports these requirements, and encourages an open market where lower product prices result from vendor competition. This paper first discusses candidate standards for wireless communication, plug-and-play
Jianchu Yao; Ryan Schmitz; Steve Warren
Personal digital assistants can provide a portable, integrated platform for point-of-care clinical reference, patient management and data communication. Clinical reference programs allow the user to access information from the Internet and guidelines. Patient management programs allow doctors to access and store clinical information. Wireless technologies have potential for rapid exchange of clinical laboratory results and efficient "electronic patient handovers". Thus, these devices provide the potential for true continuity of care across the healthcare system. PMID:11837879
Wilcox, R A; La Tella, R R
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 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
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
Over the past decade Point-of-Care Ultrasound (POC US) is increasingly performed in adult emergency medicine for a variety of indications. Pediatric emergency medicine has been much slower to embrace POC US. The authors report a case of a 15-year-old boy that presented to the pediatric emergency department with abdominal pain. A diagnosis of appendicitis was made using real-time POC US by a pediatric emergency medicine attending. Knowledge of the sonographic characteristics of appendicitis can help the physician in the prompt diagnosis of this condition, thereby reducing morbidity and mortality that may result from a delay in diagnosis.
Eakin, Paul J; Franke, Adrian A
Over the past decade Point/of/Care Ultrasound (POC US) is increasingly performed in adult emergency medicine for a variety of indications. Pediatric emergency medicine has been much slower to embrace POC US. The authors report a case of a 15/year/old boy that presented to the pediatric emergency department with abdominal pain. A diagnosis of appendicitis was made using real/time POC US by a pediatric emergency medicine attending. Knowledge of the sonographic characteristics of appendicitis can help the physician in the prompt diagnosis of this condition, thereby reducing morbidity and mortality that may result from a delay in diagnosis. PMID:20848383
Halm, Brunhild M; Eakin, Paul J; Franke, Adrian A
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
In response to Banzi's et al review of online evidence-based practice point-of-care resources published in the Journal of Medical Internet Research, the publisher of DynaMed clarifies his evidence-based methodology.
Effective pathogen detection is an essential prerequisite for the prevention and treatment of infectious diseases. Despite recent advances in biosensors, infectious diseases remain a major cause of illnesses and mortality throughout the world. For instance in developing countries, infectious diseases account for over half of the mortality rate. Pathogen detection platforms provide a fundamental tool in different fields including clinical diagnostics, pathology, drug discovery, clinical research, disease outbreaks, and food safety. Microfluidic lab-on-a-chip (LOC) devices offer many advantages for pathogen detection such as miniaturization, small sample volume, portability, rapid detection time and point-of-care diagnosis. This review paper outlines recent microfluidic based devices and LOC design strategies for pathogen detection with the main focus on the integration of different techniques that led to the development of sample-to-result devices. Several examples of recently developed devices are presented along with respective advantages and limitations of each design. Progresses made in biomarkers, sample preparation, amplification and fluid handling techniques using microfluidic platforms are also covered and strategies for multiplexing and high-throughput analysis, as well as point-of-care diagnosis, are discussed. PMID:22859057
Foudeh, Amir M; Fatanat Didar, Tohid; Veres, Teodor; Tabrizian, Maryam
New mobile computing devices including personal digital assistants (PDAs) and tablet computers have emerged to facilitate data collection at the point of care. Unfortunately, little research has been reported regarding which device is optimal for a given care setting. In this study we created and compared functionally identical applications on a Palm operating system-based PDA and a Windows-based tablet computer for point-of-care documentation of clinical observations by eye care professionals when caring for patients with diabetes. Eye-care professionals compared the devices through focus group sessions and through validated usability surveys. We found that the application on the tablet computer was preferred over the PDA for documenting the complex data related to eye care. Our findings suggest that the selection of a mobile computing platform depends on the amount and complexity of the data to be entered; the tablet computer functions better for high volume, complex data entry, and the PDA, for low volume, simple data entry. PMID:16779128
Silvey, Garry M; Macri, Jennifer M; Lee, Paul P; Lobach, David F
This paper presents the ability of the novel point-of-care protein sensing platform based on immune-like polymer membrane to separate and sense target analytes in human serum samples using the molecularly-aligned nanocavities. The separation performance of the developed membrane, which is substantially affected by surface chemistry and physics, can be enhanced by alignment of the template molecules. The developed biomimetic membrane with aligned molecular nanocavities can be synthesized and integrated with microfluidic biochips as point-of-care sensing platforms. The measurement results showed that the specific adhesion forces of the developed highly-aligned nanocavities on the immuno-like membranes are comparable to the interaction forces between CRP and biological CRP antibodies. The biomimetic polymer membrane works as antibody to catch specific proteins in complex biofluids within 110s. The proposed approach is an adaptive technological platform because it facilitates cost-effective mass production and can be applied to a wide range of protein biomarkers. PMID:23896522
Hong, Chien-Chong; Chen, Chie-Pein; Horng, Jia-Cherng; Chen, Szu-Yig
New mobile computing devices including personal digital assistants (PDAs) and tablet computers have emerged to facilitate data collection at the point of care. Unfortunately, little research has been reported regarding which device is optimal for a given care setting. In this study we created and compared functionally identical applications on a Palm operating system-based PDA and a Windows-based tablet computer for point-of-care documentation of clinical observations by eye care professionals when caring for patients with diabetes. Eye-care professionals compared the devices through focus group sessions and through validated usability surveys. We found that the application on the tablet computer was preferred over the PDA for documenting the complex data related to eye care. Our findings suggest that the selection of a mobile computing platform depends on the amount and complexity of the data to be entered; the tablet computer functions better for high volume, complex data entry, and the PDA, for low volume, simple data entry.
Silvey, Garry M.; Macri, Jennifer M.; Lee, Paul P.; Lobach, David F.
Objectives: Heart failure is one of the leading causes of death in the U.S. The incorporation of B-type natriuretic peptide (BNP) measurements when triaging patients presenting with shortness of breath has improved the diagnostic and prognostic ability of physicians. Currently, there are no point-of-care systems for quantifying BNP that can be used without sacrificing accuracy. We compared the analytical performance of the Abbott i-STAT analyzer, a handheld point-of-care system for measuring BNP, with the lab-based system, the Abbott ARCHITECT. Methods: One-hundred fifty samples were collected from three clinical settings: 41 from the Emergency Department, 58 from the inpatient wards, and 51 from heart failure outpatient clinics. Linear regression and bias difference analyses were run to evaluate the accuracy of the i-STAT. Correlation between the i-STAT and Architect BNP values were made with values of BNP. Results: The correlation coefficient was r=0.977 (N=150, p<.0001). The average bias was significant (-36) and there were concentration-dependent differences at higher BNP values. Precision of the i-STAT was poor compared to the lab-based platform. Conclusion: Although the precision of the i-STAT was poor, there was good clinical agreement between the i-STAT and the lab-based platform.
Shah, Kevin; Terracciano, Garrett J.; Jiang, Kevin; Maisel, Alan S.; Fitzgerald, Robert L.
Summary Laboratory studies of hemostasis in intensive care unit patients comprise platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT), fibrinogen, D-dimers and antithrombin. Except platelet function disorders for which presently no suitable screening test exists, the vast majority of clinically relevant disorders of hemostasis can be detected by this battery of tests. All causes of prolonged PT or
Peter Hellstern; Steinkopff Verlag
Complementary metal oxide semiconductor (CMOS)-based image sensors have received increased attention owing to the possibility of incorporating them into portable diagnostic devices. The present research examined the efficiency and sensitivity of a CMOS image sensor for the detection of antigen-antibody interactions involving interferon gamma protein without the aid of expensive instruments. The highest detection sensitivity of about 1 fg/ml primary antibody was achieved simply by a transmission mechanism. When photons are prevented from hitting the sensor surface, a reduction in digital output occurs in which the number of photons hitting the sensor surface is approximately proportional to the digital number. Nanoscale variation in substrate thickness after protein binding can be detected with high sensitivity by the CMOS image sensor. Therefore, this technique can be easily applied to smartphones or any clinical diagnostic devices for the detection of several biological entities, with high impact on the development of point-of-care applications. PMID:21773736
Marimuthu, Mohana; Kandasamy, Karthikeyan; Ahn, Chang Geun; Sung, Gun Yong; Kim, Min-Gon; Kim, Sanghyo
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
From a clinical perspective, the use of mobile technologies, such as Personal Digital Assistants (PDAs) within hospital environments is not new. A paradigm shift however is underway towards the acceptance and utility of these systems within mobile-based healthcare environments. Introducing new technologies and associated work practices has intrinsic risks which must be addressed. This paper contends that intervening to address user concerns as they arise throughout the system development lifecycle will lead to greater levels of user acceptance, while ultimately enhancing the deliverability of a system that provides a best fit with end user needs. It is envisaged this research will lead to the development of a formalised user acceptance framework based on an agile approach to user acceptance measurement. The results of an ongoing study of user perceptions towards a mandated electronic point-of-care information system in the Northern Illawarra Ambulatory Care Team (TACT) are presented. PMID:17911883
Burgess, Lois; Sargent, Jason
A point-of-care device (POCD) for measuring total white blood cell count was evaluated for feline, canine, equine and bovine blood samples collected into EDTA. Mean biases were -9.2% (range, -12% to -6.3%) for feline samples, 20.2% (range, 15.3-25.1%) for canine samples, -7.1% (range, -8.3% to -5.9%) for equine samples, and 0.7% (range, -1.1% to 2.5%) for bovine samples. The results were influenced by the presence of nucleated red blood cells. The POCD provided precise, reliable data for feline, equine and bovine samples but the values obtained for the canine counts were overestimations. PMID:22503717
Riond, Barbara; Hofmann-Lehmann, Regina; Lutz, Hans
In this study we describe a novel method of sampling and quantifying wound biomarkers for clinical settings. We believe the chosen format will allow rapid assessments of wound healing and provide biomarker evidence-based decision points for treatment of the wound at the time of presentation. The wound monitoring principle uses a proprietary sample collection tool (a thermally reversible hydrogel) to sample and isolate biomarkers within a wound environment without further sample extraction/preparation steps. We show how gel samples can be analysed in a lateral flow assay format utilising fluorescent microspheres with optically discrete emission characteristics and demonstrate quantitative detection of two analytes (duplexing) achieved in a single test line. As a model assay, the chronic wound biomarkers interleukin 6 (IL6) and tumour necrosis factor alpha (TNF?) are used. Limits of detection of 48.5 pg/mL and 55.5 pg/mL respectively in hydrogel samples and 7.15 pg/mL and 10.7 pg/mL respectively in plasma are reported. We believe this is the first literature example of quantitative detection of multiple analytes within a single test line using spectral separation to distinguish the analytes. PMID:22386484
Worsley, G J; Attree, S L; Noble, J E; Horgan, A M
In this work, robust approach for a highly sensitive point-of-care virus detection was established based on immunomagnetic nanobeads and fluorescent quantum dots (QDs). Taking advantage of immunomagnetic nanobeads functionalized with the monoclonal antibody (mAb) to the surface protein hemagglutinin (HA) of avian influenza virus (AIV) H9N2 subtype, H9N2 viruses were efficiently captured through antibody affinity binding, without pretreatment of samples. The capture kinetics could be fitted well with a first-order bimolecular reaction with a high capturing rate constant k(f) of 4.25 × 10(9) (mol/L)(-1) s(-1), which suggested that the viruses could be quickly captured by the well-dispersed and comparable-size immunomagnetic nanobeads. In order to improve the sensitivity, high-luminance QDs conjugated with streptavidin (QDs-SA) were introduced to this assay through the high affinity biotin-streptavidin system by using the biotinylated mAb in an immuno sandwich mode. We ensured the selective binding of QDs-SA to the available biotin-sites on biotinylated mAb and optimized the conditions to reduce the nonspecific adsorption of QDs-SA to get a limit of detection low up to 60 copies of viruses in 200 ?L. This approach is robust for application at the point-of-care due to its very good specificity, precision, and reproducibility with an intra-assay variability of 1.35% and an interassay variability of 3.0%, as well as its high selectivity also demonstrated by analysis of synthetic biological samples with mashed tissues and feces. Moreover, this method has been validated through a double-blind trial with 30 throat swab samples with a coincidence of 96.7% with the expected results. PMID:22309154
Zhao, Wei; Zhang, Wan-Po; Zhang, Zhi-Ling; He, Rui-Li; Lin, Yi; Xie, Min; Wang, Han-Zhong; Pang, Dai-Wen
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 ?l 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%.
Jangam, Sujit R.; Yamada, Douglas H.; McFall, Sally M.; Kelso, David M.
Background In tropical Africa, where the spectrum of the bacterial pathogens that cause fevers is poorly understood and molecular-based diagnostic laboratories are rare, the time lag between test results and patient care is a critical point for treatment of disease. Methodology/Principal Findings We implemented POC laboratory in rural Senegal to resolve the time lag between test results and patient care. During the first year of the study (February 2011 to January 2012), 440 blood specimens from febrile patients were collected in Dielmo and Ndiop villages. All samples were screened for malaria, dengue fever, Borrelia spp., Coxiella burnetii, Tropheryma whipplei, Rickettsia conorii, R. africae, R. felis, and Bartonella spp. Conclusions/Significance We identified DNA from at least one pathogenic bacterium in 80/440 (18.2%) of the samples from febrile patients. B. crocidurae was identified in 35 cases (9.5%), and R. felis DNA was found in 30 cases (6.8%). The DNA of Bartonella spp. was identified in 23/440 cases (4.3%), and DNA of C. burnetii was identified in 2 cases (0.5%). T. whipplei (0.2%) was diagnosed in one patient. No DNA of R. africae or R. conorii was identified. Among the 7 patients co-infected by two different bacteria, we found R. felis and B. crocidurae in 4 cases, B. crocidurae and Bartonella spp. in 2 cases, and B. crocidurae and C. burnetii in 1 case. Malaria was diagnosed in 54 cases. In total, at least one pathogen (bacterium or protozoa) was identified in 127/440 (28.9%) of studied samples. Here, the authors report the proof of concept of POC in rural tropical Africa. Discovering that 18.2% of acute infections can be successfully treated with doxycycline should change the treatment strategy for acute fevers in West Africa.
Fenollar, Florence; Bassene, Hubert; Diatta, Georges; Tall, Adama; Trape, Jean-Francois; Drancourt, Michel; Raoult, Didier
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
Ovarian cancer is asymptomatic at early stages and most patients present with advanced levels of disease. Lack of cost-effective methods that can achieve frequent, simple and non-invasive testing hinders early detection and causes high mortality in ovarian cancer patients. Here, we report a simple and inexpensive microchip ELISA-based detection module that employs a portable detection system, i.e., a cell phone/charge-coupled device (CCD) to quantify an ovarian cancer biomarker, HE4, in urine. Integration of a mobile application with a cell phone enabled immediate processing of microchip ELISA results, which eliminated the need for a bulky, expensive spectrophotometer. The HE4 level detected by a cell phone or a lensless CCD system was significantly elevated in urine samples from cancer patients (n = 19) than normal healthy controls (n = 20) (p < 0.001). Receiver operating characteristic (ROC) analyses showed that the microchip ELISA coupled with a cell phone running an automated analysis application had a sensitivity of 89.5% at a specificity of 90%. Under the same specificity, the microchip ELISA coupled with a CCD had a sensitivity of 84.2%. In conclusion, integration of microchip ELISA with cell phone/CCD-based colorimetric measurement technology can be used to detect HE4 biomarker at the point-of-care (POC), paving the way to create bedside technologies for diagnostics and treatment monitoring.
Wang, ShuQi; Zhao, Xiaohu; Khimji, Imran; Akbas, Ragip; Qiu, Weiliang; Edwards, Dale; Cramer, Daniel W.; Ye, Bin; Demirci, Utkan
Ovarian cancer is asymptomatic in the early stages and most patients present with advanced levels of disease. The lack of cost-effective methods that can achieve frequent, simple and non-invasive testing hinders early detection and causes high mortality in ovarian cancer patients. Here, we report a simple and inexpensive microchip ELISA-based detection module that employs a portable detection system, i.e., a cell phone/charge-coupled device (CCD) to quantify an ovarian cancer biomarker, HE4, in urine. Integration of a mobile application with a cell phone enabled immediate processing of microchip ELISA results, which eliminated the need for a bulky, expensive spectrophotometer. The HE4 level detected by a cell phone or a lensless CCD system was significantly elevated in urine samples from cancer patients (n = 19) than healthy controls (n = 20) (p < 0.001). Receiver operating characteristic (ROC) analyses showed that the microchip ELISA coupled with a cell phone running an automated analysis mobile application had a sensitivity of 89.5% at a specificity of 90%. Under the same specificity, the microchip ELISA coupled with a CCD had a sensitivity of 84.2%. In conclusion, integration of microchip ELISA with cell phone/CCD-based colorimetric measurement technology can be used to detect HE4 biomarker at the point-of-care (POC), paving the way to create bedside technologies for diagnostics and treatment monitoring. PMID:21881677
Wang, Shuqi; Zhao, Xiaohu; Khimji, Imran; Akbas, Ragip; Qiu, Weiliang; Edwards, Dale; Cramer, Daniel W; Ye, Bin; Demirci, Utkan
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
Medication dosing errors can greatly reduce HIV treatment effectiveness as incorrect dosing leads to drug resistance and non-adherence. In order to dose correctly, HIV therapy providers must balance several patient characteristics such as renal functions and weight. In developing countries and other resource-limited settings, dosing errors are more likely because treatment is provided by mid-level providers with only basic training in HIV therapy. These providers also typically lack electronic tools informing medical decisions. Widespread adoption of mobile phones in developing nations offers an opportunity to implement a point-of-care system to help providers reduce dosing errors. We discuss the development of the mHIV-Dr system prototype using the new Android mobile platform. mHIV-Dr is being designed to provide dosing recommendations for front-line providers in developing countries. We also discuss the additional challenges in the implementation of the mHIV-Dr system in a resource limited setting. PMID:21057886
Sadasivam, Rajani S; Gathibandhe, Vaibhav; Tanik, Murat M; Willig, James H
The intense demand for fluorescence-based point of care (POC) DNA diagnostics is driving developments to reduce the size of instrumentation, imposing limitations on the optical hardware that can be included. Here we describe a combination of instrumentation and fluorogenic probes to detect three fluorophores using two excitation and two detection channels. PMID:23675581
Richardson, James A; Morgan, Trevor; Andreou, Michael; Brown, Tom
Background Nucleoside reverse-transcriptase inhibitors (NRTIs) are a major component of combination antiretroviral therapy (cART) worldwide but they have been associated with mitochondrial toxicities, with one of the most significant being lactic acidosis. In southern Africa, being female and overweight (BMI > 25) as well as receiving d4T and/or ddI-based cART are risk factors for the development of this potentially life-threatening complication. It is challenging in many resource-limited settings to obtain reliable serum lactate measurements while screening for the presence of lactic acidosis. Point-of-care devices, however, are now available that provide simple, accurate measurements of serum lactate levels at relatively low cost. The objective of this study was to assess the agreement of the portable (Accutrend™ handheld) lactate analyzer to the conventional laboratory system for obtaining serum lactate. Methods Eighty two “at-risk” cART-treated adults were evaluated, having their lactate levels tested in parallel using both modalities. Results The mean (range) lactate level for the portable device was 2.28 (0.9-5.0) compared to 1.96 (0.7-5.4) using the conventional method. There was a strong correlation (p<0.05) between the portable device and the conventional means with a Pearson correlation coefficient of 0.92 [95% CI: 0.88-0.95]. The mean bias was 0.33 [95% CI: -0.39-1.04], with the portable device having slightly higher values. Conclusion The use of a portable lactate device provides an accurate and user-friendly means of screening at-risk patients for the presence of lactic acidosis in resource-limited settings with limited laboratory capacity.
Moyo, Sikhulile; Bussmann, Hermann; Mangwendeza, Phibeon; Dusara, Priti; Gaolathe, Tendani; Mine, Madisa; Musonda, Rosemary; van Widenfelt, Erik; Novitsky, Vladimir; Makhema, Joseph; Marlink, Richard G.; Essex, Max; Wester, C. William
CD4+ T cell counts are important tests used to stage HIV-positive patients, enabling clinicians to make informed antiretroviral treatment decisions and to monitor the therapeutic outcomes. However, state-of-the-art CD4 counting methods based on flow cytometry are not applicable in resource-limited settings, due to their high cost and technical requirements. In previous work, we reported the development of a cell isolation microchip that can be used at the point of care for CD4 counts. In that microfluidic chip, CD4+ T cells were separated from 10 microL of whole blood, and enumerated via either light microscopy or impedance sensing. The microchip counts matched flow cytometry results in the intermediate CD4 count range, between 200-800 cells/microL, but displayed a positive bias at absolute CD4 counts below 200 cells/microL, due largely to monocyte contamination. To enhance the performance in the low CD4 count range, we report here an improved design of a two-stage microfluidic device to deplete monocytes from whole blood, followed by CD4+ T cell capture. Using the double-stage device combined with a high viscosity rinsing solution, we obtained microchip CD4 counts comparable to flow cytometry results in the full clinically relevant range. In addition to CD4 counting, the strategy of contaminant depletion prior to target cell isolation can be easily adapted to immunoaffinity capture of other cell types that lack a unique surface marker from a complex biological fluid. PMID:19417901
Cheng, Xuanhong; Gupta, Amit; Chen, Chihchen; Tompkins, Ronald G; Rodriguez, William; Toner, Mehmet
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
Coumadin is the most dangerous medicine in common use in primary care medicine as well as in the correctional setting. In the Maryland Division of Correction’s Eastern Correctional Institution, a multivendor collaboration between the medical director and a clinical pharmacist maintained a point-of-care, finger stick international normalized ratio determination using a portable monitor. With an anticoagulation clinic protocol as a
David Mathis; Keisha OReilly
Serum antibody titers are a useful measurement of protection against infection (feline panleukopenia virus [FPV]) or clinical disease (feline herpesvirus-1 [FHV] and feline calicivirus [FCV]), and their determination has been recommended as part of disease outbreak management in animal shelters. The objective of this study was to determine the sensitivity, specificity, and inter-observer and inter-assay agreement of two semi-quantitative point-of-care
Brian A DiGangi; Lauren K Gray; Julie K Levy; Edward J Dubovi; Sylvia J Tucker
Single-step DNA detection: a microfluidic electrochemical loop mediated isothermal amplification platform is reported for rapid, sensitive, and quantitative detection of pathogen genomic DNA at the point of care. DNA amplification was electrochemically monitored in real time within a monolithic microfluidic device, thus enabling the detection of as few as 16 copies of Salmonella genomic DNA through a single-step process in less than an hour. PMID:22488842
Hsieh, Kuangwen; Patterson, Adriana S; Ferguson, B Scott; Plaxco, Kevin W; Soh, H Tom
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.
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
Background/Aims Impaired responsiveness to clopidogrel is common in patients with type 2 diabetes mellitus (DM). The aim of this study was to evaluate the clinical application of a point-of-care assay to detect impaired responsiveness to clopidogrel after coronary stent implantation in patients with type 2 DM. Methods We measured P2Y12 reaction units (PRU) with the VerifyNow point-of-care assay in 544 consecutive patients undergoing dual or triple (i.e., dual plus cilostazol) anti-platelet therapy after coronary stent implantation. High platelet reactivity (HPR) was defined as a PRU value ? 240. Results The mean PRU values were 233.5 ± 83.2 and 190.3 ± 85.5 in patients undergoing dual or triple anti-platelet therapy, respectively (p < 0.001). Patients with DM manifested higher post treatment PRU values (238.3 ± 82.4 vs. 210.8 ± 86.8, p = 0.001) and a higher frequency of HPR (44.8% vs. 31.0%, p = 0.003) as compared to patients without DM. We also found that higher PRU values and a higher frequency of HPR were present in patients with DM who were undergoing both triple and dual anti-platelet therapy. However, the higher post-treatment PRU values observed in patients with DM decreased with triple anti-platelet therapy (219.4 ± 82.5 vs. 247.9 ± 81.1, p = 0.044). Conclusions A point-of-care assay can detect elevated platelet reactivity and impaired responsiveness to clopidogrel in patients with type 2 DM. The addition of cilostazol to dual anti-platelet therapy may decrease post-treatment PRU values in patients with type 2 DM.
Yang, Tae-Hyun; Kim, Dong-Kie; Jang, Jae-Sik; Kim, Ung; Seol, Sang-Hoon; Kim, Dae-Kyeong; Hong, Geu-Ru; Park, Jong-Seon; Shin, Dong-Gu; Kim, Young-Jo; Cho, Yun-Kyeong; Nam, Chang-Wook; Hur, Seung-Ho; Kim, Kwon-Bae; Kim, Dong-Soo
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
Background: The introduction of the hand-held cardiac ultrasound (HCU) may potentially increase detection of LV hypertrophy in hypertensive patients. However, whether point-of-care screening for LV hypertrophy and concentric LV geometry by HCU in hypertensive patients is feasible and comparable to that of standard state-of-the-art echocardiography (SE) evaluation remains to be elucidated. Methods and Results: Accordingly, one hundred consecutive patients (66 female, mean age=58±13 years, 32% African-American, mean body mass index=31±8 kg/m2) with the diagnosis of hypertension underwent both HCU and SE examinations in tandem. A cardiology fellow-in-training performed the HCU exam while a cardiac sonographer performed the SE. 37% of hypertensive patients had electrocardiographic LV hypertrophy by Sokolow-Lyon or Cornell voltage criteria. Mean LV mass was 210±42 g with the HCU and 209±40 g with SE. Mean relative wall thickness was 0.45±0.05 by the HCUD and 0.44±0.05 by SE. There was excellent correlation between LV mass and relative wall thickness measurements by HCU and SE (r=0.985, SEE=6.8 g and r=0.762, SEE=0.33, respectively, both p<0.001). The prevalence of LV hypertrophy using prognostically-validated partition values for LV mass/height2.7 of 46.7 and 49.2 g/m2.7 in women and men, respectively was 76% by HCU and 78% by SE (p=NS), with excellent agreement (92%, ?=0.774, p<0.001). Agreement for detection of concentric LV geometry (relative wall thickness>0.43) was also excellent (88%, ? =0.756, p<0.001). Agreement for LV hypertrophy and concentric geometry detection between the cardiology fellow-in-training and sonographer was excellent (? =0.786, p<0.001). Conclusion: Point-of-care screening for LV hypertrophy and concentric LV geometry by HCU is feasible and correlates very well with that of SE. HCU may allow for immediate point-of-care assessment and treatment of cardiac target organ damage in hypertensive patients.
Stoica, Roxana; Heller, Eliot N; Bella, Jonathan N
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
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
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.
Letant, S E; .Ortiz, J I; Tammero, L; Birch, J M; Derlet, R W; Cohen, S; Manning, D; McBride, M T
...satellite or point-of-care testing locations. (b) Test report...request. Pertinent updates on testing information must be provided to...appropriate individual(s) of the delayed testing. (i) If a laboratory...
...satellite or point-of-care testing locations. (b) Test report...request. Pertinent updates on testing information must be provided to...appropriate individual(s) of the delayed testing. (i) If a laboratory...
In the Unites States Pediatric septic shock is a major health problem with about 42,000 cases per y ear and a mortality rate of about 10% . Studies have indicated that children with pediatric septic shock have demonstrated critically low levels of serum z inc (Zn) and supplementation of Zn is being suggested as a therapeutic strategy. However, to protect patient safety, it is vital that Z n levels be monitored during supplementation to insure the Zn concentration levels remain at or near physiologic normal levels. Currently Atomic Absorption Spectroscopy (AAS) is used to quantify Zn levels in serum samples. Unfortunately, AAS frequently involves sending serum samples to external laboratory facilities which yields measurement turnaround time that range from hours to days. Thus, timely monitoring of Zn levels is critical to preventing over supplementation that could result in critical conditions such as heavy metal (Zn) toxicity. This paper reports on the development of a Point-of-Care device for rap id electrochemical measurement of Zn. The prototype device is able to accurately quantify Zn in serum with a turn-around time of about 30 minutes. The devices is based on a three electrode sensor which uses Anodic stripping voltammetry (ASV) for sensing Zn levels. The ASV electrode sensor is read using a reader that has be en developed using commercially available embedded system components and custom analog circuitry. PMID:22255137
Sukhavasi, Sowmya; Jothimuthu, Pretha; Papautsky, Ian; Beyette, Fred R
We prospectively compared two point-of-care haemoglobin concentration measuring devices with laboratory measurements to determine their accuracy in women undergoing caesarean section delivery. The two devices were the Masimo Rainbow SET(®) Radical -7™ pulse co-oximeter and the HemoCue(®) HB 201+, which is a cuvette-type system that uses photometry. Co-oximeter readings and HemoCue measurements were taken before and after surgery, and compared with laboratory measurements of haemoglobin concentration taken at the same time. We analysed data from 137 patients using Bland-Altman plots. Limits of agreement for co-oximeter readings were -2.19 to 3.41?g.dl(-1) and for the HemoCue were -1.52 to 1.79?g.dl(-1) . The bias (mean difference) for the co-oximeter was -0.61 g.dl(-1) (95% CI 0.36 to -0.86) and for the HemoCue was 0.13?g.dl(-1) (95% CI -0.015 to 0.28). [corrected] Overall, 110/274 (40%) co-oximeter readings were within 1 g.dl(-1) of laboratory values compared with 247/274 (90%) HemoCue measurements (p 0.001 for difference). The co-oximeter gave lower readings and was less accurate than the HemoCue system when compared with laboratory measurements. PMID:23088815
Skelton, V A; Wijayasinghe, N; Sharafudeen, S; Sange, A; Parry, N S; Junghans, C
Laser-induced breakdown spectroscopy (LIBS) has made tremendous progress in becoming a viable technology for rapid bacterial pathogen detection and identification. The significant advantages of LIBS include speed (< 1 sec analysis), portability, robustness, lack of consumables, little to no need for sample preparation, lack of genetic amplification, and the ability to identify all bacterial pathogens without bias (including spore-forms and viable but nonculturable specimens). In this manuscript, we present the latest advances achieved in LIBS-based bacterial sensing including the ability to uniquely identify species from more than five bacterial genera with high-sensitivity and specificity. Bacterial identifications are completely unaffected by environment, nutrition media, or state of growth and accurate diagnoses can be made on autoclaved or UV-irradiated specimens. Efficient discrimination of bacteria at the strain level has been demonstrated. A rapid urinary tract infection diagnosis has been simulated with no sample preparation and a one second diagnosis of a pathogen surrogate has been demonstrated using advanced chemometric analysis with a simple "stop-light" user interface. Stand-off bacterial identification at a 20-m distance has been demonstrated on a field-portable instrument. This technology could be implemented in doctors' offices, clinics, or hospital laboratories for point-of-care medical specimen analysis; mounted on military medical robotic platforms for in-the- field diagnostics; or used in stand-off configuration for remote sensing and detection.
Rehse, Steven J.; Miziolek, Andrzej W.
Background Massive bleeding and transfusion of packed red blood cells (PRBC), fresh frozen plasma (FFP) and platelets are associated with increased morbidity, mortality and costs. Patients and Methods We analysed the transfusion requirements after implementation of point-of-care (POC) coagulation management algorithms based on early, calculated, goal-directed therapy with fibrinogen concentrate and prothrombin complex concentrate (PCC) in different perioperative settings (trauma surgery, visceral and transplant surgery (VTS), cardiovascular surgery (CVS) and general and surgical intensive care medicine) at 3 different hospitals (AUVA Trauma Centre Salzburg, University Hospital Innsbruck and University Hospital Essen) in 2 different countries (Austria and Germany). Results In all institutions, the implementation of POC coagulation management algorithms was associated with a reduction in the transfusion requirements for FFP by about 90% (Salzburg 94%, Innsbruck 88% and Essen 93%). Furthermore, PRBC transfusion was reduced by 8.4–62%. The incidence of intraoperative massive transfusion (?10 U PRBC) could be more than halved in VTS and CVS (2.56 vs. 0.88%; p < 0.0001 and 2.50 vs. 1.06%; p = 0.0007, respectively). Platelet transfusion could be reduced by 21–72%, except in CVS where it increased by 115% due to a 5-fold increase in patients with dual antiplatelet therapy (2.7 vs. 13.7%; p < 0.0001). Conclusions The implementation of perioperative POC coagulation management algorithms based on early, calculated, goal-directed therapy with fibrinogen concentrate and PCC is associated with a reduction in the transfusion requirements for FFP, PRBC and platelets as well as with a reduced incidence of massive transfusion. Thus, the limited blood resources can be used more efficiently.
Gorlinger, Klaus; Fries, Dietmar; Dirkmann, Daniel; Weber, Christian F.; Hanke, Alexander A.; Schochl, Herbert
In this study, characterization of the binding kinetics and optimization of a magnetic permeability based point-of-care (POC) immunoassay system for quantification of canine C-reactive protein (cCRP) is described. The reagent is based on a two-site heterogeneous immunoassay system utilizing conjugated superparamagnetic nanoparticles (SPION) and silica particles, both particles carrying covalently linked antibodies directed to the cCRP analyte. Detection is carried out using a magnetic permeability-based small instrument, adjusted in order to apply it in a POC setting near the patients. The kinetic parameters are characterized and applied in the final design of the assay system. In the cCRP system studied, 90% of the binding between immobilized solid-phase silica antibody and cCRP is complete after only 15 s, and 30 s for the binding between the antibody on the SPION and the bound cCRP on the silica particle. Additionally, the binding rate constants are determined to be 149 and 30 M(-1)s(-1), respectively. The analytical sensitivity, clinical sensitivity, and imprecision verifies the clinical usefulness of the system. Also, quantification of cCRP, using the system described, in dog clinical samples from mixed breeds shows a high correlation to a commercially available comparative cCRP ELISA system (y?=?0.98?×?+3.2, R(2)?=?0.98, n?=?47). The immunoassay system described can thus provide the veterinarian a valuable tool for rapid diagnosis and monitoring of inflammatory diseases in dogs in a setting near the patients. PMID:23660695
Ibraimi, Filiz; Ekberg, Björn; Kriz, Dario; Danielsson, Gertrud; Bülow, Leif
Assessment of trace elements such as Cu, Zn, and Se in patients with neurodegenerative disease, such as Alzheimer's (AD) and Parkinson's disease (PD), may be useful in etiologic studies and in assessing the risk of developing these conditions. A prototype point-of-care (POC) instrument based on monochromatic x-ray fluorescence (M-XRF) was assembled and evaluated for the determination of Cu, Zn, and Se in whole blood, plasma, and urine. The prototype instrument was validated using certified reference materials for Cu and Zn in serum/plasma, and the reported bias and relative imprecision were <10%. The M-XRF prototype performance was further assessed using human specimens collected from AD and PD subjects, and was found to be satisfactory (<20% bias) for monitoring Cu and Zn levels in plasma and whole blood. However, the prototype M-XRF sensitivity was not sufficient for quantifying Cu, Zn, or Se in urine. Nonetheless, while validating the prototype instrument, body fluids (whole blood, plasma, and urine) were collected from 19 AD patients, 23 PD patients, and 24 controls specifically for trace element analysis using well-validated methods based on inductively coupled plasma mass spectrometry (ICP-MS). This limited biomonitoring study provided robust data for up to 16 elements including Sb, As, Ba, Cd, Cs, Co, Cr, Cu, Hg, Pb, Mo, Se, Tl, Sn, Zn, and U in plasma, whole blood, and urine. The results did not indicate any significant differences in most trace elements studied between AD or PD patients compared to controls, although the sample size is limited. A statistically significant increase in plasma Se was identified for PD patients relative to AD patients, but this could be due to age differences. PMID:23030652
McIntosh, Kathryn G; Cusack, Matthew J; Vershinin, Alexei; Chen, Z W; Zimmerman, Earl A; Molho, Eric S; Celmins, Dzintra; Parsons, Patrick J
Oral anticoagulation with warfarin sodium has proven to be an effective therapy for patients at risk for thromboembolic disease, but due to its high risk\\/benefit ratio, many physicians are reluctant to prescribe the drug. The development of capillary whole-blood prothrombin time (PT) monitors provides a potential means to decrease this risk\\/benefit ratio and to encourage the use of warfarin. Studies
Katharine E. Leaning; Jack E. Ansell
It is clinically important to be able to detect influenza A/H1N1 virus using a fast, portable, and accurate system that has high specificity and sensitivity. To achieve this goal, it is necessary to develop a highly specific primer set that recognizes only influenza A viral genes and a rapid real-time PCR system that can detect even a single copy of the viral gene. In this study, we developed and validated a novel fluidic chip-type real-time PCR (LabChip real-time PCR) system that is sensitive and specific for the detection of influenza A/H1N1, including the pandemic influenza strain A/H1N1 of 2009. This LabChip real-time PCR system has several remarkable features: (1) It allows rapid quantitative analysis, requiring only 15 min to perform 30 cycles of real-time PCR. (2) It is portable, with a weight of only 5.5 kg. (3) The reaction cost is low, since it uses disposable plastic chips. (4) Its high efficiency is equivalent to that of commercially available tube-type real-time PCR systems. The developed disposable LabChip is an economic, heat-transferable, light-transparent, and easy-to-fabricate polymeric chip compared to conventional silicon- or glass-based labchip. In addition, our LabChip has large surface-to-volume ratios in micro channels that are required for overcoming time consumed for temperature control during real-time PCR. The efficiency of the LabChip real-time PCR system was confirmed using novel primer sets specifically targeted to the hemagglutinin (HA) gene of influenza A/H1N1 and clinical specimens. Eighty-five human clinical swab samples were tested using the LabChip real-time PCR. The results demonstrated 100% sensitivity and specificity, showing 72 positive and 13 negative cases. These results were identical to those from a tube-type real-time PCR system. This indicates that the novel LabChip real-time PCR may be an ultra-fast, quantitative, point-of-care-potential diagnostic tool for influenza A/H1N1 with a high sensitivity and specificity.
Song, Hyun-Ok; Kim, Je-Hyoung; Ryu, Ho-Sun; Lee, Dong-Hoon; Kim, Sun-Jin; Kim, Deog-Joong; Suh, In Bum; Choi, Du Young; In, Kwang-Ho; Kim, Sung-Woo; Park, Hyun
Introduction In December 2010, the World Health Organization recommended a single Xpert MTB/RIF assay as the initial diagnostic in people suspected of HIV-associated or drug resistant tuberculosis. Few data are available on the impact of this recommendation on patient outcomes. We describe the diagnostic follow-up, clinical characteristics and outcomes of a cohort of tuberculosis suspects screened using a single point-of-care Xpert. Methods Consecutive tuberculosis suspects at a primary care clinic in Johannesburg, South Africa were assessed for tuberculosis using point-of-care Xpert. Sputum smear microscopy and liquid culture were performed as reference standards. Xpert-negatives were evaluated clinically, and further assessed at the discretion of clinicians. Participants were followed for six months. Results From July-September 2011, 641 tuberculosis suspects were enrolled, of whom 69% were HIV-infected. Eight percent were positive by a single Xpert. Among 116 individuals diagnosed with TB, 66 (57%) were Xpert negative, of which 44 (67%) were empirical or radiological diagnoses and 22 (33%) were Xpert negative/culture-positive. The median time to tuberculosis treatment was 0 days (IQR: 0–0) for Xpert positives, 14 days (IQR: 5–35) for those diagnosed empirically, 14 days (IQR: 7–29) for radiological diagnoses, and 144 days (IQR: 28–180) for culture positives. Xpert negative tuberculosis cases were clinically similar to Xpert positives, including HIV status and CD4 count, and had similar treatment outcomes including mortality and time to antiretroviral treatment initiation. Conclusions In a high HIV-burden setting, a single Xpert identified less than half of those started on tuberculosis treatment, highlighting the complexity of TB diagnosis even in the Xpert era. Xpert at point-of-care resulted in same day treatment initiation in Xpert-positives, but had no impact on tuberculosis treatment outcomes or mortality.
Hanrahan, Colleen F.; Selibas, Katerina; Deery, Christopher B.; Dansey, Heather; Clouse, Kate; Bassett, Jean; Scott, Lesley; Stevens, Wendy; Sanne, Ian; Van Rie, Annelies
New federal regulations proposed by the Department of Health and Human Services for drug testing of federal employees includes\\u000a the addition of alternative specimens as well as the addition of alternative technologies for screening samples at the point\\u000a of collection. Alternative technologies called point-of-collection tests (POCT) may use urine or oral fluids, and are either\\u000a visually read or instrumented. eScreen®
The availability of rapid and sensitive methods to diagnose syphilis facilitates screening of pregnant women, which is one of the most cost-effective health interventions available. We have evaluated two screening methods in Tanzania: an enzyme immunoassay (EIA), and a point-of-care test (POCT). We evaluated the performance of each test against the Treponema pallidum particle agglutination assay (TPPA) as the reference method, and the accessibility of testing in a rural district of Tanzania. The POCT was performed in the clinic on whole blood, while the other assays were performed on plasma in the laboratory. Samples were also tested by the rapid plasma Reagin (RPR) test. With TPPA as reference assay, the sensitivity and specificity of EIA were 95.3% and 97.8%, and of the POCT were 59.6% and 99.4% respectively. The sensitivity of the POCT and EIA for active syphilis cases (TPPA positive and RPR titer ?1/8) were 82% and 100% respectively. Only 15% of antenatal clinic attenders in this district visited a health facility with a laboratory capable of performing the EIA. Although it is less sensitive than EIA, its greater accessibility, and the fact that treatment can be given on the same day, means that the use of POCT would result in a higher proportion of women with syphilis receiving treatment than with the EIA in this district of Tanzania.
Smit, Pieter W.; Mabey, David; Changalucha, John; Mngara, Julius; Clark, Benjamin; Andreasen, Aura; Todd, Jim; Urassa, Mark; Zaba, Basia; Peeling, Rosanna W.
The availability of rapid and sensitive methods to diagnose syphilis facilitates screening of pregnant women, which is one of the most cost-effective health interventions available. We have evaluated two screening methods in Tanzania: an enzyme immunoassay (EIA), and a point-of-care test (POCT). We evaluated the performance of each test against the Treponema pallidum particle agglutination assay (TPPA) as the reference method, and the accessibility of testing in a rural district of Tanzania. The POCT was performed in the clinic on whole blood, while the other assays were performed on plasma in the laboratory. Samples were also tested by the rapid plasma Reagin (RPR) test. With TPPA as reference assay, the sensitivity and specificity of EIA were 95.3% and 97.8%, and of the POCT were 59.6% and 99.4% respectively. The sensitivity of the POCT and EIA for active syphilis cases (TPPA positive and RPR titer ?1/8) were 82% and 100% respectively. Only 15% of antenatal clinic attenders in this district visited a health facility with a laboratory capable of performing the EIA. Although it is less sensitive than EIA, its greater accessibility, and the fact that treatment can be given on the same day, means that the use of POCT would result in a higher proportion of women with syphilis receiving treatment than with the EIA in this district of Tanzania. PMID:24066175
Smit, Pieter W; Mabey, David; Changalucha, John; Mngara, Julius; Clark, Benjamin; Andreasen, Aura; Todd, Jim; Urassa, Mark; Zaba, Basia; Peeling, Rosanna W
Recent epidemiological evidence indicates that chronic degenerative diseases, notably cardiovascular, represent the major toll in terms of death and of impaired quality of life. Recent estimates indicate that a small increase in financial resources in a number of clinical cases may be sufficient to minimize the consequences of elevated cardiovascular risk per individual. The observation that lifestyle choices, and in particular increased physical exercise, might strongly impact cardiovascular risk, suggests a redesign of preventive strategies, based on the combination of pharmacological and behavioral interventions. Following our recent experience with the INteractive teleConsultation network for worldwide healthcAre Services (INCAS) system, we designed a simpler point-to-point telehealth infrastructure, to be employed in cardiovascular risk reduction programs, predicting a high level of acceptance from the population, at the cost of very limited investment. This model was tested on 181 subjects (ages 18-80 years) in the Italian mountain village of Esino Lario. These subjects underwent a screening test to evaluate arrhythmia and cardiometabolic risks (arrhythmias were found in 14% of subjects, systolic arterial pressure was observed in 43% of subjects above 140 mm Hg, diastolic arterial pressure in 31% above 90 mm Hg). This study demonstrates the feasibility of a scaled-down telehealth application particularly suited to cardiovascular prevention in remote areas, such as in mountain villages. PMID:19199851
Malacarne, Mara; Gobbi, Giorgio; Pizzinelli, Paolo; Lesma, Alessandro; Castelli, Alberto; Lucini, Daniela; Pagani, Massimo
Background Routine HIV screening in emergency department (ED) settings may require dedicated personnel. We evaluated the outcomes, costs and cost-effectiveness of HIV screening when offered by either a member of the ED staff or by an HIV counselor. Methods We employed a mathematical model to extend data obtained from a randomized clinical trial of provider- vs. counselor-based HIV screening in the ED. We compared the downstream survival, costs, and cost-effectiveness of three HIV screening modalities: 1) no screening program; 2) an ED provider-based program; and 3) an HIV counselor-based program. Trial arm-specific data were used for test offer and acceptance rates (provider offer 36%, acceptance 75%; counselor offer 80%, acceptance 71%). Undiagnosed HIV prevalence (0.4%) and linkage to care rates (80%) were assumed to be equal between the screening modalities. Personnel costs were derived from trial-based resource utilization data. We examined the generalizability of results by conducting sensitivity analyses on offer and acceptance rates, undetected HIV prevalence, and costs. Results Estimated HIV screening costs in the provider and counselor arms averaged $8.10 and $31.00 per result received. The Provider strategy (compared to no screening) had an incremental cost-effectiveness ratio of $58,700/quality-adjusted life year (QALY) and the Counselor strategy (compared to the Provider strategy) had an incremental cost-effectiveness ratio of $64,500/QALY. Results were sensitive to the relative offer and acceptance rates by strategy and the capacity of providers to target-screen, but were robust to changes in undiagnosed HIV prevalence and programmatic costs. Conclusions The cost-effectiveness of provider-based HIV screening in an emergency department setting compares favorably to other US screening programs. Despite its additional cost, counselor-based screening delivers just as much return on investment as provider based-screening. Investment in dedicated HIV screening personnel is justified in situations where ED staff resources may be insufficient to provide comprehensive, sustainable screening services.
Walensky, Rochelle P.; Morris, Bethany L.; Reichmann, William M.; Paltiel, A. David; Arbelaez, Christian; Donnell-Fink, Laurel; Katz, Jeffrey N.; Losina, Elena
The optimal use of laboratory tests requires an understanding of the many variables which may influence the result and its interpretation. This is especially important with the increasing use of point-of-care testing. In this article we cover how to request the ‘right test’ as well as the many variables. Also, common tests are discussed.
Peter Rae; Suzanne M. MacKenzie
Variability in response to antiplatelet agents has prompted the development of point-of-care (POC) technology. In this study, we compared the VerifyNow P2Y12 (VN-P2Y12) POC device with light transmission aggregometry (LTA) in subjects switched directly from clopidogrel to prasugrel. Healthy subjects on aspirin were administered a clopidogrel 600 mg loading dose (LD) followed by a 75 mg/d maintenance dose (MD) for 10 days. Subjects were then switched to a prasugrel 60 mg LD and then 10 mg/d MD for 10 days (n = 16), or to a prasugrel 10 mg/d MD for 11 days (n = 19). Platelet function was measured by LTA and VN-P2Y12 at baseline and after dosing. Clopidogrel 600 mg LD/75 mg MD treatment led to a reduction in P2Y(12) reaction units (PRU) from baseline. A switch from clopidogrel MD to prasugrel 60 mg LD/10 mg MD produced an immediate decrease in PRU, while a switch to prasugrel 10 mg MD resulted in a more gradual decline. Consistent with the reduction in PRU, device-reported percent inhibition increased during both clopidogrel and prasugrel regimens. Inhibition of platelet aggregation as measured by LTA showed a very similar pattern to that found with VN-P2Y12 measurement, irrespective of treatment regimens. The dynamic range of VN-P2Y12 appeared to be narrower than that of LTA. With two different thienopyridines, the VN-P2Y12 device, within a somewhat more limited range, reflected the overall magnitude of change in aggregation response determined by LTA. The determination of the clinical utility of such POC devices will require their use in clinical outcome studies. PMID:18278193
Jakubowski, Joseph A; Payne, Christopher D; Li, Ying G; Brandt, John T; Small, David S; Farid, Nagy A; Salazar, Daniel E; Winters, Kenneth J
BACKGROUND: Imported malaria occurs as a relatively rare event in developed countries. As a consequence, most clinicians have little experience in making clinical assessments of disease severity and decisions regarding the need for parenteral therapy or high-level monitoring. In this study, the diagnostic accuracy of procalcitonin (PCT) for severe Plasmodium falciparum disease was assessed in a cohort of 100 consecutive
Dennis A Hesselink; Jan-Steven Burgerhart; Hanna Bosmans-Timmerarends; Pieter Petit; Perry JJ van Genderen
Objectives: To evaluate prospectively four rapid, point-of-care serological tests for syphilis in prenatal or high risk populations in four countries. Methods: Tests were performed on consecutive clinic attendees, using whole blood in the clinic, and whole blood and serum in the laboratory. The sensitivity and specificity of each test was evaluated, using a standard treponemal test (Treponema pallidum haemagglutination assay
D Mabey; R W Peeling; R Ballard; A S Benzaken; E Galban; J Changalucha; D Everett; R Balira; D Fitzgerald; P Joseph; S Nerette; J Li; H Zheng
In the present paper a novel optical system for the monitoring and measurements of different analytes in Point of Care Testing (POCT) is presented. It is based on an optical biochip constituted by a two-piece polymethylmetacrylate (PMMA) chip, with 13 microchannels through which the analysed sample flows, and the sensing layer, where the immunochemical reaction takes place, is located on the bottom side of the upper piece of the PMMA chip. All the electronics, optoelectronics and fluidics components are embedded in a portable instrument is totally controlled by software. Preliminary tests on C-reactive protein (CRP) and procalcitonin (PCT) immunoassay are reported.
Baldini, F.; Bolzoni, L.; Giannetti, A.; Porro, G.; Trono, C.
The mini-health technology assessment (HTA) tool is valuable in assessing the quality of decisions regarding health technology management in South African public hospitals. The tool demonstrates the needs for improved decision-making and for developing an appropriate, customised instrument to support decision makers regarding medical device management. Health technology in South Africa has changed rapidly over the past two decades. Current challenges include the introduction of rapidly developing diagnostic technologies such as point-of-care testing (POCT) devices and national health insurance. The mini-HTA tool can play an important role in effective and efficient management of health technology in this setting. PMID:22272960
Govender, Moreshnee; Mueller, Debjani B; Basu, Debashis
Using 255 serum samples with various reactivities, we evaluated the Syphilis Fast latex agglutination test (Syphilis Fast) against the Treponema pallidum particle agglutination test (TP-PA) for confirming a diagnosis of syphilis. We found 98.8% agreement between the Syphilis Fast and the TP-PA. The Syphilis Fast, however, had a couple of advantages over the TP-PA: the test takes only 8 min to perform and produces results that are easy to read. It appears to be a good confirmatory test for syphilis, especially for point-of-care clinics such as prenatal or sexually transmitted disease clinics.
Fears, Martha B.; Pope, Victoria
Dependability is an important attribute for microfluidic biochips that are used for safety-critical applications, such as point-of-care health assessment, air-quality monitoring, and food-safety testing. Therefore, these devices must be adequately tested after manufacture and during bioassay operations. Known techniques for biochip testing are all function oblivious (i.e., while they can detect and locate defect sites on a microfluidic array, they
Tao Xu; Krishnendu Chakrabarty
This communication describes a very simple, rapid and inexpensive point-of-care diagnostic test for sickle cell disease (SCD) that can conclusively differentiate between blood samples from normal healthy individuals, sickle cell trait carriers and SCD patients using the characteristic blood stain patterns produced by each sample on paper. PMID:23429713
Yang, Xiaoxi; Kanter, Julie; Piety, Nathaniel Z; Benton, Melody S; Vignes, Seth M; Shevkoplyas, Sergey S
Signify® ER Drug Screen Test (Signify ER) and Triage® Drug of Abuse Panel plus TCA (Triage DOA Panel) rapid drug screening devices were compared at four laboratories. Both assay systems are point of care immunoassays, measuring phencyclidine, barbiturates, amphetamine, cocaine metabolite, methamphetamine, tricyclic antidepressants, opiates, marijuana metabolite, and benzodiazepines in human urine. The performance of these two assay systems, including
Jane Ellen Phillips; Stuart Bogema; Paul Fu; Wieslaw Furmaga; Alan H. B Wu; Vlasta Zic; Catherine Hammett-Stabler
Clinical laboratories provide an invaluable service to millions of people around the world in the form of quality diagnostic care. Within the clinical laboratory industry the impetus for change has come from technological development (miniaturization, nanotechnology, and their collective effect on point-of-care testing; POCT) and the increasingly global nature of laboratory services. Potential technological gains in POCT include: the development of bio-sensors, microarrays, genetics and proteomics testing, and enhanced web connectivity. In globalization, prospective opportunities lie in: medical tourism, the migration of healthcare workers, cross-border delivery of testing, and the establishment of accredited laboratories in previously unexplored markets. Accompanying these impressive opportunities are equally imposing challenges. Difficulty transitioning from research to clinical use, poor infrastructure in developing countries, cultural differences and national barriers to global trade are only a few examples. Dealing with the issues presented by globalization and the impact of developing technology on POCT, and on the clinical laboratory services industry in general, will be a daunting task. Despite such concerns, with appropriate countermeasures it will be possible to address the challenges posed. Future laboratory success will be largely dependent on one's ability to adapt in this perpetually shifting landscape. PMID:21175379
Melo, Murilo R; Clark, Samantha; Barrio, Daniel
Background: Antibiotics are commonly overused in adults seeking emergency department (ED) care for acute cough illness. Objective: To evaluate the effect of a point-of-care C-reactive protein (CRP) blood test on antibiotic treatment of acute cough illness in adults. Methods: A randomized controlled trial was conducted in a single urban ED in the United States. The participants were adults (age ?
Ralph Gonzales; Eva M. Aagaard; Carlos A. Camargo; O. John Ma; Mark Plautz; Judith H. Maselli; Charles E. McCulloch; Sara K. Levin; Joshua P. Metlay
As the conversion to an electronic health record intensifies, the question of which data-entry device works best in what environment and situation is paramount. Specifically, what is the best mix of equipment to purchase and install on clinical units based on staff preferences and budget constraints? The authors discuss their evaluation of stationary personal computers, workshops on wheels, and handheld tablets related to timeliness of data entry and their use of focus groups to ascertain the pros/cons of data-entry devices and staff preferences. An assessment of the implications for costs related to the timeliness of data entry is also presented. PMID:20798618
Carlson, Elizabeth; Catrambone, Cathy; Oder, Karl; Nauseda, Susan; Fogg, Lou; Garcia, Brian; Brown, Frederick M; Johnson, Mary E; Johnson, Tricia J; Llewellyn, Jane
The discrimination of viral and bacterial sepsis is an important issue in intensive care patients. For this purpose, the simultaneous measurements of different analytes are necessary. Among the possible candidates, C-reactive protein (CRP) and procalcitonin (PCT) are probably the most important ones. A novel optical platform was designed and realised for the implementation of fluorescence-based immunoassays. The core of the optical platform is a plastic biochip, constituted by 13 microchannels (50 ?m high, 600 ?m width, 10 mm long) through which the sample flows. The sensing layer, where the immunochemical reaction takes place, is located on the upper part of each microchannel. The chip is interrogated with a novel optoelectronic platform, based on fluorescence anisotropy. A line-shaped beam from a 635-nm laser-diode excites perpendicularly the sensing layer and great many of the emitted remains entrapped inside the chip. The particular shape of the top of the chip allows to guide the emitted fluorescence along the same direction of the microchannel. The fluorescence which comes out on the lateral side from the chip is collected by a single plastic optical fibre and sent to an amplified photodiode. The device was characterised by the implementation of the sandwich assay for CRP and PCT spiked in serum. Limit of quantifications of 4.5 and of 6 ?g L-1 in serum solution were achieved for CRP and PCT, respectively.
Baldini, F.; Bolzoni, L.; Giannetti, A.; Porro, G.; Senesi, F.; Trono, C.
Introduction A 13-year-old boy presented to the emergency department with left knee pain after a fall. Initial radiographs were unremarkable,\\u000a but the child returned to the emergency department 6 weeks later with persistent symptoms.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods A bedside sonogram of the left hip performed by the treating emergency physician demonstrated a widened epiphyseal plate and\\u000a an associated effusion, consisted with a slipped
Michael B. Stone; Chameeka Barrett
This hour-long video from the University of WashingtonÃ¢ÂÂs Molecular Medicine Training Program explains microfluidicsÃ¢ÂÂa technology for manipulating small volumes of fluid that could have a major impact on global health by enabling the development of a portable and inexpensive system for detecting pathogens.
Nancy Maizels (University of Washington;University of Washington Molecular Medicine Trainging program)
Paper-based immunoassays are becoming powerful and low-cost diagnostic tools, especially in resource-limited settings. Inexpensive methods for quantifying these assays have been shown using desktop scanners, which lack portability, and cameras, which suffer from the ever changing ambient light conditions. In this work, we introduce a novel approach of quantifying colors of colorimetric diagnostic assays with a smartphone that allows high accuracy measurements in a wide range of ambient conditions, making it a truly portable system. Instead of directly using the red, green, and blue (RGB) intensities of the color images taken by a smartphone camera, we use chromaticity values to construct calibration curves of analyte concentrations. We demonstrate the high accuracy of this approach in pH measurements with linear response ranges of 1-12. These results are comparable to those reported using a desktop scanner or silicon photodetectors. To make the approach adoptable under different lighting conditions, we developed a calibration technique to compensate for measurement errors due to variability in ambient light. This technique is applicable to a number of common light sources, such as sun light, fluorescent light, or smartphone LED light. Ultimately, the entire approach can be integrated in an "app" to enable one-click reading, making our smartphone based approach operable without any professional training or complex instrumentation. PMID:22996728
Shen, Li; Hagen, Joshua A; Papautsky, Ian
The University of Washington's "UWTV" website is an archive of talks by visitors to the University as well as professors, librarians, and others who have a formal association with the institution. The talks cover a myriad of topics from urban planning to zoology, and this specific talk looks into the world of health care provisioning in the developing world. The talk is by Professor Paul Yager of the bioengineering department at the UW, and he offers information and findings about a new technology for manipulating small volumes of fluids. This technology will help health care professionals as they work to create a small portable and inexpensive system for detecting pathogens far from any centralized laboratory. It's an engaging hour-long talk, and one that will be of interest to persons in the health care and public health fields.
Dependability is an important attribute for microfluidic biochips that are used for safety-critical applications such as point-of-care health assessment, air-quality monitoring, and food-safety testing. Therefore, these devices must be adequately tested after manufacture and during bioassay operations. Moreover, since disposable biochips are being targeted for a highly competitive and low-cost market segment, test and diagnosis methods should be inexpensive, quick,
Tao Xu; Krishnendu Chakrabarty
Objectives? To evaluate the performance of two enzyme immunoassays (EIA), Murex and ICE, and the Determine TP point-of-care test (POCT) in diagnosing treponemal infection (syphilis or yaws) in patients attending a large HIV clinic in Ghana; to determine the prevalence of treponemal co-infections; and to characterise demographic and clinical features of patients with infection. Methods? Samples were tested with EIAs and rapid plasma reagin (RPR), then POCT and reference assays for Treponema pallidum to determine prevalence of active and past infection. Sensitivity and specificity of each assay were calculated and demographic and clinical characteristics of patients compared. Data were collected from case notes of patients retrospectively. Results? Overall, 45/284 patient samples (14.8%, 95% CI, 11.1-19.4%) were Treponema pallidum particle agglutination (TPPA) positive, and of these, 27 (64.3%) were RPR positive and 4 (8.9%) were treponemal IgM positive. Both EIAs and Determine TP POCT showed high sensitivities and specificities for identifying infection although RPR was less reliable. Clinical features of syphilis or yaws were rarely identified in TPPA-positive patients suggesting most had previous or late latent infection. Treatment of various intercurrent infections using short courses of antibiotics active against T. pallidum was common in the clinic. Conclusions? A high proportion of this HIV-infected cohort showed evidence of treponemal infection. Both EIAs as well as the POCT were practical and effective at diagnosing treponemal co-infection in this setting. RPR alone was unreliable at identifying active treponemal co-infection, however might be useful in some settings where treponemal-specific assays are unaffordable. PMID:22994205
Mamoojee, Yaasir; Tan, Grace; Gittins, Sandra; Sarfo, Stephen; Stephenson, Lisa; Carrington, David; Bedu-Addo, George; Phillips, Richard; Appiah, Lambert T; Chadwick, David
Respiratory syncytial virus (RSV) is the most important cause of infantile bronchiolitis and pneumonia. It is ubiquitous, with most children acquiring their primary infection within the first year of life and with subsequent reinfection occurring in all age groups. Clinically, RSV is virtually indistinguishable from other viral respiratory infections. Traditionally, the microbiologic diagnosis of RSV has been based on moderate to complex techniques performed in a laboratory (cell culture, nucleic acid amplification and immunofluorescence assays); however, rapid antigen-detection tests offer potential advantages associated with point-of-care testing. This review seeks to familiarize the readers with RSV rapid antigen-detection tests, describe their performance characteristics and comment on their strengths and weaknesses. The authors will discuss the impact of rapid RSV testing on clinical practice, with a look to the future of what the field ultimately requires of a point-of-care diagnostic technique. PMID:23534357
Prendergast, Caitlin; Papenburg, Jesse
|Parent-offspring conflict theory (POCT) has been underutilized in studies of human family dynamics. An implication of POCT is that the presence of siblings will increase conflict in biological parent-child dyads, and that half siblings will increase that conflict more than full siblings. Evidence consistent with this prediction was found in a…
Schlomer, Gabriel L.; Ellis, Bruce J.; Garber, Judy
A plastic biochip was developed for the detection of procalcitonin (PCT) and consists of a polymethylmethacrylate (PMMA) chip shaped in order to achieve several flow microchannels. A sandwich assay using a new antibody pairs is implemented with the capture antibody immobilized on the PMMA surface and the target antibody labelled with a fluorophore. A laser diode excites the fluorescent sensing layer. Thanks to the anisotropy of the fluorescence the emitted light travels along the thickness of the plastic material. The fluorescence coming out from the chip is collected by 1 mm plastic optical fibre and detected with a spectrum analyser.
Baldini, Francesco; Bolzoni, Luca; Giannetti, Ambra; Kess, Melanie; Kraemer, Petra M.; Kremmer, Elisabeth; Porro, Giampiero; Senesi, Folco; Trono, Cosimo
Diagnosing HIV infection in infants by p24 antigen detection at point of care is likely to reduce infant morbidity and mortality. A fourth-generation rapid test evaluated on 202 stored samples from children of known age and clinical presentation demonstrated a sensitivity of <2% for detecting p24 antigen in 61 HIV-infected infants and demonstrated 100% sensitivity and specificity for detecting HIV antibodies in infants aged 6 months and younger. PMID:23190776
Bhowan, Kapila; Sherman, Gayle G
A method for patterning narrow lines of biomolecules onto nitrocellulose membranes using laboratory syringe pumps is described. One syringe pump is used to drive the biomolecule solution through a needle, while another modified syringe pump acts as a one-dimensional translation stage, moving the needle across the membrane much like a pen. This method consumes very small volumes of reagents, and is a viable option for laboratory-scale fabrication and prototyping of point-of-care rapid diagnostic test strips.
Nash, Michael A.; Hoffman, John M.; Stevens, Dean Y.; Hoffman, Allan S.; Stayton, Patrick S.; Yager, Paul
Reviews 43 publications on tests. The publications of J. R. Angell, W. B. Pillsburg, C. E. Seashore, R. S. Woodworth and F. L. Wells, and R. M. Yerkes and J. B. Watson, presented development of methods of testing single mental processes. The second group of tests dealing with single or groups of mental processes for determining their value as methods
Frank N. Freeman
|This is a report of the findings and recommendations of the Division of Instruction and Professional Development of the National Education Association (NEA) on testing. NEA called for a moratorium on standardized testing in 1972 and created the task force on testing, whose work is summarized in this report. After an introduction stating the…
National Education Association, Washington, DC. Div. of Instruction and Professional Development.
This study reports the use of microfluidics, which intrinsically has a large surface-to-volume ratio, toward rapid antimicrobial susceptibility testing at the point of care. By observing the growth of uropathogenic E. coli in gas permeable polymeric microchannels with different dimensions, we demonstrate that the large surface-to-volume ratio of microfluidic systems facilitates rapid growth of bacteria. For microchannels with 250 micrometer or less in depth, the effective oxygenation can sustain the growth of E. coli to over 109 cfu/ml without external agitation or oxygenation, which eliminates the requirement of bulky instrumentation and facilitates rapid bacterial growth for antimicrobial susceptibility testing at the point of care. The applicability of microfluidic rapid antimicrobial susceptibility testing is demonstrated in culture media and in urine with clinical bacterial isolates that have different antimicrobial resistance profiles. The antimicrobial resistance pattern can be determined as rapidly as 2 hours compared to days in standard clinical procedures facilitating diagnostics at the point of care.
Chen, Chia Hsiang; Lu, Yi; Sin, Mandy L. Y.; Mach, Kathleen E.; Zhang, Donna D.; Gau, Vincent; Liao, Joseph C.; Wong, Pak Kin
This review examines human chorionic gonadotropin (hCG) or pregnancy tests from multiple perspectives. It first investigates the molecule hCG and shows that the term represents five independent molecules differing in carbohydrate and meric structure that share a common amino acid sequence. The review goes on to show that multiple degradation produces also the need to be tested for an hCG or pregnancy test to be optimally efficient. The review then carefully examines the literature showing the sensitivity and specificity of automated laboratory tests. Point-of-care pregnancy tests are then investigated along with over-the-counter pregnancy tests. Appropriate detection of hyperglycosylated hCG, nicked hCG, nicked hCG missing the ?-subunit C-terminal peptide and nicked hyperglycosylated hCG is a limitation on all pregnancy tests. In the opinion of the author, just one automated laboratory test, the Siemen’s Immulite, one point-of-care test, the Beckman-Coulter Icon 25, and one brand of over-the-counter device, First Response, are suitable for early pregnancy detection and possibly other applications. PMID:22149742
Cole, Laurence A
Total cholesterol (TC) and low-density lipoprotein cholesterol (LDLC) levels are positively related to coronary heart disease (CHD), and high-density lipoprotein cholesterol (HDLC) levels are negatively related to CHD. Efforts to identify and treat people at increased risk based on cholesterol and lipoprotein levels have led to more lipid testing and the need for very reliable test results. Point-of-care testing (POCT) has developed from the demand for analytical information more fastly than is available from central laboratories. By carrying the analysis closer to the patient some 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 (TATs), decreased blood loss as a result of reduced phlebotomy secondary to clinical improvement and diminished resource utilization. These effects depend on acceptable analytical performance in comparison with central laboratory techniques and in relation to clinical criteria. PMID:18700691
Sblendorio, V; Palmieri, B
HIV diagnostic and follow up testing are usually done in laboratory settings. However, in developing countries there is a need to decentralize testing as the majority of the population lives in rural settings. In developing countries stringent quality assurance (QA) practices, which include appropriate training, development of standard operating procedures, maintenance of operator proficiency, routine use of quality control (QC) specimens, standardized data management, equipment calibration and maintenance, and biohazard safety with proper disinfection/disposal procedures are not routinely followed to ensure reliability of results and a safe work environment. The introduction of point-of-care testing technologies involving the use of non-laboratorians in routine testing has further increased the complexity of QA. Therefore, a careful approach towards improvement of laboratories that encourages best practices, coupled with incentives, and review of government policies in point-of-care testing is needed to improve quality of testing as decentralization takes place. Development of a functional laboratory tiered network that facilitates communication, referral, training and problem solving could further enhance confidence in laboratory testing. There is also a need for special considerations in implementing a step-wise approach towards quality improvement, strengthening of the supply chain management, human capacity development, infrastructure upgrade, and strong public private partnerships to ensure long term sustainability of these efforts.
Alemnji, George; Nkengasong, John N.; Parekh, Bharat S.
The U.S. Department of Health and Human Services (HHS) drug testing standards were published in 1988 and revised in 1994, 1998, and 2004. In 2004, significant revisions defining, standardizing, and requiring specimen validity testing on Federal employee donor urine specimens were included. In a separate notice, HHS proposed to establish scientific and technical guidelines for the Federal Workplace Drug Testing Program to: (1) permit laboratory testing of hair, oral fluid, and sweat patch specimens in addition to urine specimens for marijuana, cocaine, phencyclidine, opiates (with focus on heroin), and amphetamines [including methylenedioxymethamphetamine (MDMA), methylenedioxyethamphetamine (MDEA), methylenedioxyamphetamine (MDA)]; (2) permit use of on-site point of collection test (POCT) devices to test urine and oral fluid at collection sites; (3) permit use of instrumented initial test (screening only) facilities [IITF] to quickly identify negative specimens; and (4) add training requirement for collectors, on-site testers, and MROs. This proposal was published in the Federal Register on 13 April 2004, with a 90-day public comment period. The Substance Abuse and Mental Health Services Administration, HHS, reviewed those comments and is preparing the Final Notice that will define the requirements for such testing, including: specimen collection procedures, custody and control procedures that ensure donor specimen identity and integrity, testing facility, initial and confirmatory test cutoff concentrations, analytical testing methods, result review and reporting, evaluation of alternative medical explanations for presence of drug or metabolite in the donor's specimen, and laboratory certification issues. Voluntary pilot performance testing (PT) programs for each specimen type are on-going since April 2000 to determine how to prepare PT materials for specimens other than urine to evaluate laboratories' ability to routinely achieve accuracy and precision required. Certification programs will be developed using the current urine drug testing National Laboratory Certification Program model. The addition of accurate and reliable workplace drug testing using hair, oral fluid, and sweat patch specimens will complement urine drug testing, and aid in combating industries devoted to suborning drug testing through adulteration, substitution, and dilution. For example, hair testing may detect chronic drug use for up to 90 days and be useful in pre-employment situations; oral fluid testing may detect drug use in past hours and be useful in post-accident situations; sweat patch testing may be useful in follow-up drug testing and treatment programs; POCTs and IITFs may be most useful for quickly identifying specimens that are negative for drugs and indicate that the specimen is valid. PMID:17434274
Bush, Donna M
Despite the high prevalence of herpes simplex virus type 2 (HSV-2), testing for asymptomatic infections is uncommon. One population for whom targeted interventions may be prioritized include individuals involved with the correctional system. Here we describe the acceptability of a novel HSV-2 screening program, implemented in a court setting, as a possible intervention for corrections-involved women. Female defendants completed an interviewer administered survey assessing factors associated with uptake/refusal of free point-of-care HSV-2 serologic testing and HSV-2 seropositivity. Participants included 143 women, 18-62 years old (mean 32.85) with diverse ethnicities. The majority (65.7%) accepted testing and 62.4% tested HSV-2 seropositive. Factors independently associated with test acceptance included higher perceived susceptibility to genital herpes infection and not receiving a preventative health screen. Women who were seropositive tended to be older, Black, report having previous STI, and be arrested on a prostitution charge. Findings suggest point-of-care testing in a court setting is acceptable to women and can be implemented to improve case finding of STI. PMID:23467289
Roth, A M; Van Der Pol, B; Fortenberry, J D; Reece, M; Dodge, B; Certo, D; Zimet, G D
To develop a miniature complete blood count (CBC) analyzer for point-of-care testing (POCT), a MEMS CBC sensor based on the impedance method is discussed. A novel MEMS CBC sensor that is fabricated through a simple photolithography process using SU-8 is realized. However, the fabricated sensor exhibits a noisy output signal due to electrolysis gas. The relationship between the noise and the gas is revealed through microscopic observation and finite element method (FEM) simulation. To solve the problem of electrolysis gas, an improved MEMS CBC sensor with vanes is developed. The improved sensor is unaffected by electrolysis gas. Moreover, the signal stability of the sensor and the signals detected for latex particles are successfully evaluated.
Tanabe, Rikiya; Hata, Seiichi; Shimokohbe, Akira
MagArray™ chips contain arrays of magnetic sensors, which can be used to detect surface binding reactions of biological molecules that have been labeled with 10 to 100 nm sized magnetic particles. Although MagArray chips are in some ways similar to fluorescence-based DNA array chips, the use of magnetic labeling tags leads to many distinct advantages, such as better background rejection, no label bleaching, inexpensive chip readers, potentially higher sensitivity, ability to measure multiple binding reactions in homogeneous assays simultaneously and in real-time, and seamless integration with magnetic separation techniques. So far, the technology of MagArray chips has been successfully used to perform quantitative analytic bioassays of both protein and nucleic acid targets. The potential of this technology, especially for point-of-care testing (POCT) and portable molecular diagnostics, appears promising, and it is likely that this technology will see significant further performance gains in the near future.
Osterfeld, Sebastian J.; Wang, Shan X.
This work presents novel components for on-chip storage and dispensing inside a lab-on-a-chip (LOC) for applications in immunoassay point-of-care testing (POCT), where incubation and washing steps are essential. It involves easy-to-use on-chip solutions for the sequential thermo-hydraulic actuation of liquids. The novel concept of combining the use of a rubber plug, both as a non-return valve cap and as a liquid injection interface of a sealed reservoir, allows simple filling of a sterilized cavity, as well as the storage and dispensing of reagent and washing buffer liquids. Segmenting the flow with air spacers enables effective rinsing and the use of small volumes of on-chip stored liquids. The chip uses low-resistance resistors as heaters in the paraffin actuator, providing the low-voltage actuation that is preferred for handheld battery driven instruments.
Bodén, Roger; Lehto, Marcus; Margell, Joakim; Hjort, Klas; Schweitz, Jan-Åke
The need for companion diagnostics, point-of-care testing (POCT) and high-throughput screening in clinical diagnostics and personalized medicine has pushed the need for more biological information from a single sample at extremely low concentrations and volumes. Optical biosensors based on semiconductor quantum dots (QDs) can answer these requirements because their unique photophysical properties are ideally suited for highly sensitive multiplexed detection. Many different biological systems have been successfully scrutinized with a large variety of QDs over the past decade but their future as widely applied commercial biosensors is still open. In this review, we highlight recent in vitro diagnostic and cellular imaging applications of QDs and discuss milestones and obstacles on their way toward integration into real-life diagnostic and medical applications. PMID:22608980
Jin, Zongwen; Hildebrandt, Niko
Background. Point-of-care testing (POCT) coagulometers are increasingly being used in the hospital setting. We investigated whether the prothrombin time international normalized ratio (INR) results by CoaguChek XS Plus (Roche Diagnostics GmbH, Mannheim, Germany) can be used reliably without being confirmed with the INR results by STA-R system (Diagnostica Stago S.A.S, Asnières sur Seine, France). Methods. A total of 118 INR measurements by CoaguChek XS Plus and STA-R were compared using Passing/Bablok regression analysis and Bland-Altman plot. Agreement of the INR measurements was further assessed in relation to dosing decision. Results. The correlation of INR measurements between CoaguChek XS Plus and STA-R was excellent (correlation coefficient = 0.964). The mean difference tended to increase as INR results increased and was 0.25 INR in the therapeutic range (2.0-3.0 INR). The overall agreement was fair to good (kappa = 0.679), and 21/118 (17.8%) INR measurements showed a difference in dosing decision. Conclusion. The positive bias of CoaguChek XS Plus may be obvious even in the therapeutic INR range, and dosing decision based on the CoaguChek XS Plus INR results would be different from that based on the STA-R results. The INR measurements by POCT coagulometers still need to be confirmed with the laboratory INR measurements.
Hur, Mina; Kim, Hanah; Park, Chul Min; La Gioia, Antonio; Choi, Sang-Gyu; Choi, Ju-Hee; Moon, Hee-Won; Yun, Yeo-Min
Women participating in studies in Brazil (n = 695) and South Africa (n = 230) performed rapid point-of-care tests for Trichomonas vaginalis on self-collected vaginal swabs. Using PCR as the gold standard, rapid self-testing achieved high specificity (99.1%; 95% confidence interval [CI], 98.2 to 99.6%) and moderate sensitivity (76.7%; 95% CI, 61.4 to 88.2%). These tests may be considered an alternative to syndromic management in resource-poor settings.
Lippman, Sheri A.; Caiaffa-Filho, Helio H.; Young, Taryn; van de Wijgert, Janneke H. H. M.
On November 7, 2002, the Food and Drug Administration announced approval of the OraQuick Rapid HIV-1 Antibody Test (OraSure Technologies, Inc., Bethlehem, Pennsylvania) for use by trained personnel as a point-of-care test to aid in the diagnosis of infection with human immunodeficiency virus type 1 (HIV-1). OraQuick is a simple, rapid test that can detect antibodies to HIV in fingerstick whole blood specimens and provide results in as little as 20 minutes [corrected]. The test has been categorized as moderate complexity under the Clinical Laboratory Improvement Amendments of 1988 (CLIA). A second FDA-approved moderate-complexity rapid HIV test, Single Use Diagnostic System for HIV-1 (Abbott-Murex Inc., Norcross, Georgia), remains available in the United States for use with serum or plasma specimens. PMID:12487529
Background: Antibiotics are commonly overused in adults seeking emergency department (ED) care for acute cough illness. Objective: To evaluate the effect of a point-of-care C-reactive protein (CRP) blood test on antibiotic treatment of acute cough illness in adults. Methods: A randomized controlled trial was conducted in a single urban ED in the United States. The participants were adults (age ? 18 years) seeking care for acute cough illness (? 21 days duration); 139 participants were enrolled, and 131 completed the ED visit. Between November 2005 and March 2006, study participants had attached to their medical charts a clinical algorithm with recommendations for chest X-ray study or antibiotic treatment. For CRP-tested patients, recommendations were based on the same algorithm plus the CRP level. Results: There was no difference in antibiotic use between CRP-tested and control participants (37% [95% confidence interval (CI) 29-45%] vs. 31% [95% CI 23-39%], respectively; p = 0.46) or chest X-ray use (52% [95% CI 43-61%] vs. 48% [95% CI 39-57%], respectively; p = 0.67). Among CRP-tested participants, those with normal CRP levels received antibiotics much less frequently than those with indeterminate CRP levels (20% [95% CI 7-33%] vs. 50% [95% CI 32-68%], respectively; p = 0.01). Conclusions: Point-of-care CRP testing does not seem to provide any additional value beyond a point-of-care clinical decision support for reducing antibiotic use in adults with acute cough illness. PMID:19095403
Gonzales, Ralph; Aagaard, Eva M; Camargo, Carlos A; Ma, O John; Plautz, Mark; Maselli, Judith H; McCulloch, Charles E; Levin, Sara K; Metlay, Joshua P
Background Emergency department (ED) visits for hyperglycemia are common and costly. Enhanced strategies for recognizing and managing patients with diabetes in the ED are needed. Hemoglobin A1c (A1C) testing is typically used to assess level of glycemic control in the 2–3 months preceding an office visit. In this article, we report on potential roles for point-of-care (POC) A1C testing in the ED for patients presenting with uncontrolled hyperglycemia. Methods We enrolled patients presenting to an urban tertiary care hospital ED with blood glucose (BG) ?200 mg/dl who were otherwise stable for discharge (n = 86) in a prospective, nonrandomized pilot study. Antihyperglycemic medication management, survival-skills diabetes self-management education, and health system navigation were provided. Followup visits took place at 24–72 hours and at 2 and 4 weeks. Point-of-care A1C testing was performed at baseline and at 2 weeks. Baseline A1C results were used by the ED physician and the educator to inform the patient of likely preadmission glycemic classification, and the potential role that the (diabetes mellitus) DM medication regimen assigned in the ED had in enabling overall progress in glycemic control at 2 weeks post-ED initiation of treatment. Results At baseline, 50% of POC A1C values were >13%. Mean BG fell from 356 ± 110 mg/dl to 183 ± 103 mg/dl at 4 weeks (average decrease of 173.5 g/dl, p < 0.001). Mean A1C fell by 0.4%, from 12.0 ± 1.5% to 11.6 ± 1.6% at 2 weeks, p = 0.048. There were zero instances of day 1 hypoglycemia and overall hypoglycemia rates were low (1.3%). Conclusions Point-of-care A1C testing in the ED helped inform both the provider and the patient of likely prior glycemic status, including unrecognized or uncontrolled type 2 diabetes, and allowed emphasis of the importance of timely diabetes self-management education and medication management in preventing acute and chronic complications. Followup POC A1C testing at 2 weeks was used to confirm early improvement in glycemic control postintervention.
Magee, Michelle F; Nassar, Carine
In this work, we report advances in the fabrication and anticipated performance of a polymer biosensor photonic chip developed in the European Union project P3SENS (FP7-ICT4-248304). Due to the low cost requirements of point-ofcare applications, the photonic chip is fabricated from nanocomposite polymeric materials, using highly scalable nanoimprint- lithography (NIL). A suitable microfluidic structure transporting the analyte solutions to the sensor area is also fabricated in polymer and adequately bonded to the photonic chip. We first discuss the design and the simulated performance of a high-Q resonant cavity photonic crystal sensor made of a high refractive index polyimide core waveguide on a low index polymer cladding. We then report the advances in doped and undoped polymer thin film processing and characterization for fabricating the photonic sensor chip. Finally the development of the microfluidic chip is presented in details, including the characterisation of the fluidic behaviour, the technological and material aspects of the 3D polymer structuring and the stable adhesion strategies for bonding the fluidic and the photonic chips, with regards to the constraints imposed by the bioreceptors supposedly already present on the sensors.
Dortu, F.; Egger, H.; Kolari, K.; Haatainen, T.; Furjes, P.; Fekete, Z.; Bernier, D.; Sharp, G.; Lahiri, B.; Kurunczi, S.; Sanchez, J.-C.; Turck, N.; Petrik, P.; Patko, D.; Horvath, R.; Eiden, S.; Aalto, T.; Watts, S.; Johnson, N. P.; de La Rue, R. M.; Giannone, D.
Smell of success: Reagent 1 provides the dual readouts of odor (ethanethiol) and fluorescence (derivative of 7-hydroxycoumarin) and can be used in down-selection assays based on smell and quantitative fluorescence assays of the samples that give a positive result. An important feature of 1 is the matched sensitivity of the two outputs. This reagent is designed for use in resource-limited settings and is demonstrated in assays that detect enzymes. PMID:23038662
Mohapatra, Hemakesh; Phillips, Scott T
Introduction: Diplomates in the American Board of Internal Medicine (ABIM) Maintenance of Certification (MOC) program satisfy the self-evaluation of medical knowledge requirement by completing open-book multiple-choice exams. However, this method remains unlikely to affect practice change and often covers content areas not relevant to diplomates'…
Green, Michael L.; Reddy, Siddharta G.; Holmboe, Eric
Nursing Reference Center (NRC) is a new database offering from EBSCO Industries, Inc. The intended audience is nurses at all levels of the profession: students, hospital nurses, nurse educators, administrators, and faculty. Content is derived from a number of resources ranging from legal cases to research instruments. It is a big product with lots of ways to approach the information.
We describe an optical system which reduces the cost and complexity of fluorescence correlation spectroscopy (FCS), intended to increase the suitability of the technique for clinical use. Integration of the focusing optics and sample chamber into a plastic component produces a design which is simple to align and operate. We validate the system by measurements on fluorescent dye, and compare the results to a commercial instrument. In addition, we demonstrate its application to measurements of concentration and multimerization of the clinically relevant protein von Willebrand factor (vWF) in human plasma. PMID:23847733
Olson, Eben; Torres, Richard; Levene, Michael J
Study objective: rapidly identifying anemia through qualitative observation of the palpebral conjunctiva for pallor is standard medical practice. We report on the ability of using a fiber optic array probe to collect diffusely reflected light from the palpebral conjunctiva and measure hemoglobin concentration noninvasively. Patients (N=102) admitted to the emergency department and receiving a complete blood count (CBQ were enrolled
Gregory D. Jay; Justin Racht; John McMurdy; Zara Mathews; Ashley Hughes; S. Suner; G. Crawford
Traditionally, home care for chronically ill patients and the elderly requires periodic visits to the patient's home by doctors or healthcare personnel. During these visits, the visiting person usually records the patient's vital signs and takes decisions as to any change in treatment and address any issues that the patient may have. Patient monitoring systems have since changed this scenario by significantly reducing the number of home visits while not compromising on continuous monitoring. This paper describes the design and development of a patient monitoring systems capable of concurrent remote monitoring of 8 patient-worn sensors: Electroencephalogram (EEG), Electrocardiogram (ECG), temperature, airflow pressure, movement and chest expansion. These sensors provide vital signs useful for monitoring the health of chronically ill patients and alerts can be raised if certain specified signal levels fall above or below a preset threshold value. The data from all eight sensors are digitally transmitted to a PC or to a standalone network appliance which relays the data through an available internet connection to the remote monitoring client. Thus it provides a real-time rendering of the patient's health at a remote location.
Whitchurch, Ashwin K.; Abraham, Jose K.; Varadan, Vijay K.
We present a miniature micro-electro-mechanical systems (MEMS)-based dual-axis confocal microscope capable of spatially co-registered fluorescence imaging at multiple wavelengths. This device has a 10-mm diameter scan head with a 2-mm diameter tip for convenient use during surgery to guide tumor resection. The microscope has an adjustable focal depth from 20 – 200 microns and is capable of imaging with an axial resolution of 9 microns and in-plane resolution of 4 microns over a field of view of 450 × 450 microns. Simultaneous two-color imaging of individual optical sections is achieved by using a pair of grating-prism assemblies (GRISMs) to compensate for chromatic dispersion in the 2-mm diameter gradient-index (GRIN) relay lens at the distal tip of the device. Experimental measurements of the axial response of the microscope as well as two-color images of a reflective bar target and fresh mouse brain tissues demonstrate the performance of our device and its potential for multi-color in vivo optical-sectioning microscopy.
Leigh, Steven Y.; Liu, Jonathan T.C.
There is the need for a clinical assay to determine the extent to which a patient's blood is effectively anticoagulated by the low-molecular-weight-heparin (LMWH), enoxaparin. There are also urgent clinical situations where it would be important if this could be determined rapidly. The present assay is designed to accomplish this. We only assayed human blood samples that were spiked with known concentrations of enoxaparin. The essential feature of the present assay is the quantification of the efficacy of enoxaparin in a patient's blood sample by degrading it to complete inactivity with heparinase. Two blood samples were drawn into Vacutainer tubes (Becton-Dickenson; Franklin Lakes, NJ) that were spiked with enoxaparin; one sample was digested with heparinase for 5 min at 37 °C, the other sample represented the patient's baseline anticoagulated status. The percent shortening of clotting time in the heparinase-treated sample, as compared to the baseline state, yielded the anticoagulant contribution of enoxaparin. We used the portable, battery operated Hemochron 801 apparatus for measurements of clotting times (International Technidyne Corp., Edison, NJ). The apparatus has 2 thermostatically controlled (37 °C) assay tube wells. We conducted the assays in two types of assay cartridges that are available from the manufacturer of the instrument. One cartridge was modified to increase its sensitivity. We removed the kaolin from the FTK-ACT cartridge by extensive rinsing with distilled water, leaving only the glass surface of the tube, and perhaps the detection magnet, as activators. We called this our minimally activated assay (MAA). The use of a minimally activated assay has been studied by us and others. (2-4) The second cartridge that was studied was an activated partial thromboplastin time (aPTT) assay (A104). This was used as supplied from the manufacturer. The thermostated wells of the instrument were used for both the heparinase digestion and coagulation assays. The assay can be completed within 10 min. The MAA assay showed robust changes in clotting time after heparinase digestion of enoxaparin over a typical clinical concentration range. At 0.2 anti-Xa I.U. of enoxaparin per ml of blood sample, heparinase digestion caused an average decrease of 9.8% (20.4 sec) in clotting time; at 1.0 I.U. per ml of enoxaparin there was a 41.4% decrease (148.8 sec). This report only presents the experimental application of the assay; its value in a clinical setting must still be established. PMID:23093300
Inchiosa, Mario A; Pothula, Suryanarayana; Kubal, Keshar; Sanchala, Vajubhai T; Navarro, Iris
The information retrieval systems currently available in general practice, such as Medline, and web search engines are passive and relatively difficult to access during consultations. Emergent technologies, including the National Electronic Library for Health, offer opportunities for more active decision support. We examine the extent to which information retrieval could support primary care consultations by examining the impact of the new technology at different stages of the consultation. We advocate a system whereby professional organisations concerned with quality of care, such as the Royal College of General Practitioners, might contribute the the process.
Sullivan, F; Gardner, M; van Rijsbergen, K
We implemented a computerized decision support tool to standardize the administration of supplemental oxygen (O2) therapy in the acute care (non-ICU) hospital setting. Caregiver acceptance of the computerizeds oxygen therapy protocol (COTP) instructions was measured to determine the clinical performance of the computerized decision support tool. 49.6% of instructions generated were followed by the clinical caregiver, and 16.8% of instructions generated were explicitly acknowledged by the user through the COTP computer interface. Despite this low caregiver response rate, significant favorable changes in the administration of oxygen were observed. This paper is focused on the issues of general importance the caregiver response rate raises for the implementation and clinical use of computerized decision support tools, including: (1) limitations of the user interface and (2) inherent difficulty in changing long-standing practice patterns.
Wallace, C. J.; Metcalf, S.; Zhang, X.; Kinder, A. T.; Greenway, L.; Morris, A. H.
|Introduction: Diplomates in the American Board of Internal Medicine (ABIM) Maintenance of Certification (MOC) program satisfy the self-evaluation of medical knowledge requirement by completing open-book multiple-choice exams. However, this method remains unlikely to affect practice change and often covers content areas not relevant to diplomates'…
Green, Michael L.; Reddy, Siddharta G.; Holmboe, Eric
The electronic dissemination of medical knowledge in the form of executable clinical guidelines and decision support systems must be accompanied by comprehensive methods for ensuring the quality of their knowledge content and their safety in use. This paper outlines a set of quality and safety requirements, and reviews three current guideline technologies, the Arden Syntax, GLIF and PROforma, against these requirements. The approaches used in these technologies have different strengths, and we propose a general framework for ensuring quality and safety that combines them. This framework brings together the normal documentation standards of medical publishing, rigorous design methods from software engineering, and active safety management techniques from artificial intelligence. PMID:11079882
Fox, J; Bury, J
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
Adarsh Sandhu; Hiroshi Handa; Masanori Abe
In compliance with the Paperwork Reduction Act (PRA) of 1995 (44 U.S.C. 3501-3521), this notice announces that the Veterans Health Administration, Department of Veterans Affairs, will submit the collection of information abstracted below to the Office of Management and Budget (OMB) for review and comment. The PRA submission describes the nature of the information collection and its expected cost......
Background Ketonuria (on standard urine testing) is a frequent finding in children presenting to emergency departments. With the advent of hand?held ketone meters, blood ketone levels can now be rapidly quantified. Hypothesis Point of care testing (POCT) of blood ketone levels could provide clinically useful information on severity of illness in children and risk of hospital admission. Methods A prospective study using POCT of blood ketone levels in a convenience sample of children <13?years old, with a typical case mix of medical problems. Findings 186 children were studied. The range of ketone levels varied widely among this study population depending on the presenting complaint. Higher levels were noted in those presenting with anorexia or vomiting and fever. The median ketone level of the total study population was 0.2 (range 0–6.0, interquartile range 0.1–0.9)?mmol/l. Ketone levels correlated poorly with discharge destination and duration of admission. However, receiver–operator characteristics for ketones as a predictor of admission were comparable to Pediatric Risk of Admission scores (area under the curve 0.64 and 0.72, respectively) and may represent an independent risk factor for admission. A ketone level >1.2?mmol/l has a positive predictive value of 66.7% for admission. Ketone levels correlated well with decreased oral intake (R2?=?0.25; p<0.001). Conclusions A strong association was found between ketone levels, decreased oral intake and fever. Although ketone levels do not correlate well with more traditional markers of illness severity, they can help to predict the requirement for admission to hospital when interpreted in the context of the presenting illness. They may have applications in both the emergency department and primary care settings. Further prospective testing is required to validate these findings.
O'Donohoe, P B; Kessler, R; Beattie, T F
China is experiencing a syphilis epidemic of enormous proportions. The regions most heavily affected by syphilis correspond to regions where sexually transmitted HIV infection is also a major public health threat. Many high-risk patients in China fail to receive routine syphilis screening. This missed public health opportunity stems from both a failure of many high-risk individuals to seek clinical care and a disconnect between policy and practice. New point-of-care syphilis testing enables screening in non-traditional settings such as community organizations or sex venues. This paper describes the current Chinese syphilis policies, suggests a spatiotemporal framework (based on targeting high-risk times and places) to improve screening and care practices, and emphasizes a syphilis control policy extending beyond the clinical setting. PMID:20539859
Tucker, Joseph D; Hawkes, Sarah J; Yin, Yue-Pin; Peeling, Rosanna W; Cohen, Myron S; Chen, Xiang-Sheng
Up to 33% of HIV-infected adults in the UK remain undiagnosed and efforts to increase HIV testing are underway. HIV testing was conducted amongst individuals presenting to a polyclinic at a central London hospital using a point of care test. Demographic and HIV risk data was collected along with a patient feedback questionnaire exploring acceptability of the HIV testing experience. Seventy-one out of 93 (76%) individuals accepted HIV testing. Of those accepting HIV testing, 53/71 (75%) had never previously tested for HIV despite, 45/53 (85%) of these being registered with a GP. Twenty-seven out of 71 (38%) of individuals testing had at least one risk factor associated with HIV acquisition, and of these 17/27 (63%) had never previously tested for HIV infection. There were no new HIV positive diagnoses during the period of testing. Respondents indicated a high level of satisfaction with the service and more than 85% found the service to be helpful, educational and convenient. This small proof of concept pilot showed uptake of HIV testing in this setting to be high and acceptable to patients. PMID:22272938
Ashby, J; Braithewaite, B; Walsh, J; Gnani, S; Fidler, S; Cooke, G
Exploiting the high sensitivity of the chemiluminescence phenomenon, an accurate and sensitive point-of-care test, called the ZstatFlu-II test (ZymeTx, Inc., Oklahoma City, Okla.), was developed to detect influenza virus infections. The ZstatFlu-II test takes 20 min and requires approximately 2 min of "hands-on" time for operational steps. The ZstatFlu-II test does not distinguish between infections with influenza virus types A and B. ZstatFlu-II test results are printed on Polaroid High-Speed Detector Film, allowing test results to be archived. A prototype version of the ZstatFlu-II test was evaluated during the 2000-to-2001 flu season with 300 nasal aspirate specimens from children at a pediatric hospital. Compared to culture, the ZstatFlu-II test had 88% sensitivity and 92% specificity. The Directigen test had a sensitivity of 75% and a specificity of 93%. The sensitivity of the ZstatFlu-II test was significantly higher than that of the Directigen test (P < 0.0574). PMID:12089243
Hamilton, Marilyn S; Abel, David M; Ballam, Yolanda J; Otto, Mary K; Nickell, Angela F; Pence, Lisa M; Appleman, James R; Shimasaki, Craig D; Achyuthan, Komandoor E
Background For the diagnosis of seasonal influenza, clinicians rely on point-of-care testing (POCT) using commercially available kits developed against seasonal influenza viruses. However, POCT has not yet been established for the diagnosis of pandemic influenza A virus (H1N1pdm) infection due to the low sensitivity of the existing kits for H1N1pdm. Methodology/Principal Findings An immunochromatography (IC) test kit was developed based on a monoclonal antibody against H1N1pdm, which does not cross-react with seasonal influenza A or B viruses. The efficacy of this kit (PDM-IC kit) for the diagnosis of H1N1pdm infection was compared with that of an existing kit for the detection of seasonal influenza viruses (SEA-IC kit). Nasal swabs (n?=?542) were obtained from patients with flu-like syndrome at 13 clinics in Osaka, Japan during the winter of 2010/2011. Among the 542 samples, randomly selected 332 were further evaluated for viral presence by reverse transcriptase polymerase chain reaction (RT-PCR). The PDM-IC kit versus the SEA-IC kit showed higher sensitivity to and specificity for H1N1pdm, despite several inconsistencies between the two kits or between the kits and RT-PCR. Consequently, greater numbers of false-negative and false-positive cases were documented when the SEA-IC kit was employed. Significant correlation coefficients for sensitivity, specificity, and negative prediction values between the two kits were observed at individual clinics, indicating that the results could be affected by clinic-related techniques for sampling and kit handling. Importantly, many patients (especially influenza-negative cases) were prescribed anti-influenza drugs that were incongruous with their condition, largely due to physician preference for patient responses to questionnaires and patient symptomology, as opposed to actual viral presence. Conclusions/Significance Concomitant use of SEA-IC and PDM-IC kits increased the likelihood of correct influenza diagnosis. Increasing the credibility of POCT is anticipated to decrease the inappropriate dispensing of anti-influenza drugs, thereby minimizing the emergence of drug-resistant H1N1pdm strains.
Sasaki, Tadahiro; Kubota-Koketsu, Ritsuko; Takei, Michihiro; Hagihara, Tatsuo; Iwamoto, Shinichi; Murao, Takuya; Sawami, Kazuo; Fukae, Daizou; Nakamura, Masahiro; Nagata, Eiichi; Kawakami, Akira; Mitsubayashi, Yuko; Ohno, Masafumi; Uehara, Yasuo; Fukukawa, Takashi; Kanai, Yuta; Kosaka, Mieko; Ikuta, Kazuyoshi
HIV/AIDS disease is endemic in Nigeria and associated with stigmatization. Availability of a reliable rapid testing kit and procedure will increase uptake of services. The study aimed to determine the correlation between detection of HIV antibodies in blood to that in oral fluid and to determine the sensitivity and specificity of the Dual Path Platform (DPP) testing kit using oral fluid samples. HIV antibodies detected in oral mucosa transudate and whole capillary blood from HIV-positive, high-risk and low-risk participants were compared with results obtained with whole venous blood from the same participants tested with Determine and Western blot (for discordant cases). Oral fluid test has sensitivity and specificity of 100% relative to Determine rapid assay, while whole capillary blood test has sensitivity of 100% and specificity of 99.5%. DPP oral fluid test is a reliable point-of-care test and may be deployed in large-scale screening exercises. PMID:21396537
Iregbu, Kenneth C; Esfandiari, Javan; Nnorom, Joseph; Sonibare, Samuel A; Uwaezuoke, Stella N; Eze, Stella O; Abdullahi, Nasiru; Lawal, Akeem O; Durogbola, Babatunde S
Purpose Two point-of-care (POC) tests are available to detect bacterial vaginosis (BV), a common vaginal condition. This study aimed to 1) compare the accuracy of two self-performed BV tests to clinician-performed BV tests and to clinical BV; and 2) compare trust of results for self-BV testing compared to clinician-BV testing. Methods Participants (14–22 years old) in a study assessing self-testing for Trichomonas vaginalis were also asked to perform a self-test for BV (using a pH or sialidase test). Results were compared to clinician-tests and to clinical BV (defined by modified Amsel’s criteria). A two-item subscale from a larger acceptability scale was used to assess trust at baseline, after testing, and after discussion of results. Results All 131 women performed self-BV testing correctly. Agreement between self- and clinician-tests was good (Kappa 0.5–0.7). Compared to clinical BV, self-pH was 73% sensitive and 67% specific, and self-sialidase was 40% sensitive and 90% specific. Trust in self-BV testing was lower than trust in clinician-BV testing at baseline, but increased after testing and discussion of results. Conclusions Young women can perform self-tests for BV with reasonable accuracy, which could increase testing when pelvic exams are not feasible. Trust in self-testing increased after experience and after discussion of test results. Although the pH test is over-the-counter, young women may continue to rely on clinicians for testing.
Huppert, Jill S.; Hesse, Elizabeth A.; Bernard, Marianne Claire; Bates, Justin R.; Gaydos, Charlotte A.; Kahn, Jessica A.
Abstract Background: After excluding pulmonary embolism (PE) with an unlikely Wells-decision rule and a negative D-dimer test, the general practitioner still has to differentiate between clinically relevant and clinically non-relevant diseases accounting for the presented symptoms. A negative D-dimer test makes clinically relevant disease less likely. The C-reactive protein (CRP) test could be of additional value to make this differentiation. Objectives: To assess whether an unlikely Wells-decision rule in combination with a negative point of care D-dimer test not only can safely exclude PE but also, in combination with a negative CRP-test, any other clinically relevant disease. Methods: We used data of a prospective study including 598 primary care patients suspected of pulmonary embolism. We included all patients, referred to secondary care for reference testing, with an unlikely Wells-decision rule and a negative point of care D-dimer test. We included 191 patients and imputed the CRP-test results in 60 patients. Alternative diagnoses were divided in clinically relevant diseases and clinically non-relevant diseases. A ROC-curve was constructed to determine the optimal CRP-cut-off. Results: The optimal CRP cut-off value appeared to be 10 mg/l. A total of 116 patients had a CRP < 10 mg/l of whom 12 patients (10%) had a clinically relevant disease. Two patients (2%) needed hospital admission. A total of 75 patients had a CRP ? 10 mg/l of whom 32 patients (43%) had a clinically relevant disease. Fifteen patients (20%) were admitted to hospital. Conclusion: The CRP-test is enhancing diagnostic decision making in patients in whom the general practitioner excluded PE. PMID:23577661
Lucassen, Wim A M; Kuijs-Augustijn, Marlous; Erkens, Petra M G; Geersing, Geert-Jan; Büller, Harry R; van Weert, Henk C P M
There is great interest in point-of-care antibody testing for the diagnosis of infectious and autoimmune diseases. As a first step in the development of self-contained and miniaturized devices for highly quantitative antibody detection, we demonstrate the application of Luciferase Immunoprecipitation Systems (LIPS) technology in a microfluidic format. Protein A/G was immobilized on the walls of PDMS-glass microchannels of 500 nL volume. The assay proceeds with the simultaneous introduction of plasma and Renilla luciferase–tagged antigens. Following washing, coelenterazine substrate was added and bound antigen-luciferase measured by chemiluminescence. Total assay time, including rinsing and detection, is under ten minutes. Using these stable microfluidic devices, high diagnostic performance (100% sensitivity and 100% specificity) was achieved for the diagnosis of HSV-2 infection. Based on these findings, the LIPS microfluidic format should readily lend itself to automation and the transfer to portable instrumentation.
Zubair, Adnan; Burbelo, Peter D.; Vincent, Ludovic G.; Iadarola, Michael J.; Smith, Paul D.; Morgan, Nicole Y.
MicroRNAs (miRNAs) have been identified as promising cancer biomarkers due to their stable presence in serum. As an alternative to PCR-based homogenous assays, surface-based electrochemical biosensors offer great opportunities for low-cost, point-of-care tests (POCTs) of disease-associated miRNAs. Nevertheless, the sensitivity of miRNA sensors is often limited by mass transport and crowding effects at the water-electrode interface. To address such challenges, we herein report a DNA nanostructure-based interfacial engineering approach to enhance binding recognition at the gold electrode surface and drastically improve the detection sensitivity. By employing this novel strategy, we can directly detect as few as attomolar (<1, 000 copies) miRNAs with high single-base discrimination ability. Given that this ultrasensitive electrochemical miRNA sensor (EMRS) is highly reproducible and essentially free of prior target labeling and PCR amplification, we also demonstrate its application by analyzing miRNA expression levels in clinical samples from esophageal squamous cell carcinoma (ESCC) patients.
Wen, Yanli; Pei, Hao; Shen, Ye; Xi, Junjie; Lin, Meihua; Lu, Na; Shen, Xizhong; Li, Jiong; Fan, Chunhai
Recently, digital photography has become an efficient and economic method to assist dermatologists in monitoring skin characteristics. Although this technology has advanced a great deal in resolution and costs, conventional digital cameras continue to only provide qualitative recording of color information. To address this issue, we are developing a compact, quantitative skin imaging camera by employing spatial frequency domain imaging (SFDI), a non-contact approach for determining tissue optical properties over a wide field-of-view. SFDI uses knowledge of optical properties at multiple wavelengths to recover concentrations of tissue constituents such as oxy/deoxy-hemoglobin, water, and melanin. This method has been well researched and presented in laboratory and research settings. The next step in the development of SFDI systems is to make typical systems compact and cheaper using commercial components. We present our findings by performing a component-by-component analysis of key SFDI system components including light sources, projectors, and cameras.
Nadeau, K. P.; Khoury, P.; Mazhar, A.; Cuccia, D.; Durkin, A. J.
Objective: To conduct a prospective cohort study to determine the frequency and characteristics of Shiga toxin (Stx)-producing Escherichia coli (STEC) infections in children with diarrhea attending an emergency department and a private clinic in Seattle, Washington. Methods: Between November 1998 and October 2001, 1851 stools were processed for STEC by sorbitol-MacConkey (SMAC) agar screening and a commercial Stx enzyme immunoassay
Eileen J. Klein; Jennifer R. Stapp; Carla R. Clausen; Daniel R. Boster; Joy G. Wells; Xuan Qin; David L. Swerdlow; Phillip I. Tarr
The CoaguChek XS international normalized ratio (INR) assay was compared to INR assay by a standard laboratory method in children with heart disease on anticoagulant therapy. The data comprised 120 pairs of INR values for 42 patients (age <16 yr) who attended a cardiology clinic between 1 May 2007 and 30 January 2008. Parallel INR assays by the CoaguChek XS and the standard method were performed within 1 hr by a single qualified technician and the paired results were evaluated by linear regression and Bland-Altman analysis. The mean difference in the INR values was -0.08 +/- 0.04 units (p = 0.63); the difference between the two results was consistently <0.5 INR units. The slope of the regression line was 0.98 (95% CI: 0.96 to 1.01) and the y-intercept was 0.014 (95% CI: -0.01 to 0.04). In the Bland-Altman analysis, the mean difference in INR between the two methods was 0.08 units and values for 99.4% of the patients fell within the limit of agreement (-0.17 to 0.28 units). In summary, INR assays in children by the CoaguChek XS device are as accurate as the standard method, but faster and more convenient. PMID:20689136
Moon, Ju Ryoung; Jeong, Soo In; Huh, June; Lee, Heung Jae; Park, Pyo Won; Kang, I-Seok
A method for label-free, electrochemical impedance immunosensing for the detection and quantification of three infection biomarkers in both buffer and directly in the defined model matrix of mock wound fluid is demonstrated. Triggering Receptor-1 Expressed on Myeloid cells (TREM-1) and Matrix MetalloPeptidase 9 (MMP-9) are detected via direct assay and N-3-oxo-dodecanoyl-l-HomoSerineLactone (HSL), relevant in bacterial quorum sensing, is detected using a competition assay. Detection is performed with gold screen-printed electrodes modified with a specific thiolated antibody. Detection is achieved in less than 1h straight from mock wound fluid without any extensive sample preparation steps. The limits of detection of 3.3 pM for TREM-1, 1.1 nM for MMP-9 and 1.4 nM for HSL are either near or below the threshold required to indicate infection. A relatively large dynamic range for sensor response is also found, consistent with interaction between neighbouring antibody-antigen complexes in the close-packed surface layer. Together, these three novel electrochemical immunosensors demonstrate viable multi-parameter sensing with the required sensitivity for rapid wound infection detection directly from a clinically relevant specimen. PMID:22137369
Ciani, Ilenia; Schulze, Holger; Corrigan, Damion K; Henihan, Grace; Giraud, Gerard; Terry, Jonathan G; Walton, Anthony J; Pethig, Ronald; Ghazal, Peter; Crain, Jason; Campbell, Colin J; Bachmann, Till T; Mount, Andrew R
Chronic illness including cardiovascular disease (CVD) is a major burden on the healthcare system. Behavioral and lifestyle changes could significantly reduce the burden of CVD, but provider counseling for behavior change is a very challenging, and often ineffective task. We have developed a patient-centric decision support tool to be incorporated into an Electronic Health Record system (EHR). The tool provides tailored feedback on behavioral risk, readiness and confidence in an effort to empower patients to make decisions about improving health behaviors. In turn, the tool will facilitate an informed and balanced discussion between patients and their providers about behavioral changes, incorporating both the clinical view and the individual’s preferences for choosing among multiple behavior change goals based on their psychosocial characteristics, and evaluation of benefits and barriers.
Li, Jianhua; Khan, Sharib A.; Mark, Jessica; Nivarthi, Phani K.; Misra, Rupa; Chan, Connie; Kaufman, David; Kukafka, Rita
...Manipulated Autologous Peripheral Blood Stem Cells; Availability AGENCY: Food and...Manipulated Autologous Peripheral Blood Stem Cells (PBSCs)'' dated July 2007. The...Manipulated Autologous Peripheral Blood Stem Cells (PBSCs)'' dated July 2007....
This paper describes the development and characterisation of labeless immunosensors for (a) the cardiac drug digoxin and (b) bovine serum albumin (BSA). Commercial screen-printed carbon electrodes were used as the basis for the sensors. Two methods were used to immobilise antibodies at the electrode surface. Aniline was electropolymerised onto these electrodes to form a thin planar film of conductive polyaniline; the polyaniline film was then utilised as a substrate to immobilise biotinylated anti-digoxin using a classical avidin-biotin affinity approach. As an alternative approach, poly(1,2-diaminobenzene) was electrodeposited onto the carbon electrodes and this modified surface was then sonochemically ablated to form an array of micropores. A second electropolymerisation step was then used to co-deposit conductive polyaniline along with antibodies for BSA within these pores to produce a microarray of polyaniline protrusions with diameters of several mum, containing entrapped anti-BSA. The resulting antibody grafted electrodes were interrogated using an AC impedance protocol before and following exposure to digoxin or BSA solutions, along with control samples containing a non-specific IgG antibody. The impedance characteristics of both types of electrode were changed by increasing concentrations of antigen up to a saturation level. Calibration curves were obtained by subtraction of the non-specific response from the specific response, thereby el