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Pediatric Endocrinology Reviews : PER Mar 2011Blood glucose testing by point-of-care (POC) meters has become increasingly prevalent, and is an essential tool in diabetes management. But most of those who use the... (Review)
Review
Blood glucose testing by point-of-care (POC) meters has become increasingly prevalent, and is an essential tool in diabetes management. But most of those who use the meters or rely upon their results for clinical decision-making are unaware of the significant limitations of these meters at present in both inpatient and outpatient settings. This review discusses the limitations of both strips and meters, in both hospital and outpatient settings, and the special problems when caring for diabetes in children and adolescents. It presents data that support the general concern among the experts that POC glucose meters are often inappropriate in critical care, as well reviewing when these meters are appropriate for use in other settings. The review discusses the problem of "outliers", glucose levels that deviate from the true glucose by a relatively large increment, and how these degrade clinical decision-making. Lastly, evidence-based recommendations are provided for changes that are needed to improve the present situation.
Topics: Adolescent; Blood Glucose; Child; Diabetes Mellitus; Diagnostic Errors; Humans; Point-of-Care Systems; Reagent Strips; Reference Standards; Sensitivity and Specificity
PubMed: 21525796
DOI: No ID Found -
Veterinary Clinical Pathology 2002Monitoring of urine pH, often done in the patient s home, is essential for proper clinical treatment and management of conditions such as urolithiasis. (Comparative Study)
Comparative Study
BACKGROUND
Monitoring of urine pH, often done in the patient s home, is essential for proper clinical treatment and management of conditions such as urolithiasis.
OBJECTIVE
The purpose of this study was to assess the agreement in pH readings between a standard laboratory method and methods readily available for home monitoring. The influence of refrigerated storage on urine pH was also examined.
METHODS
Urine samples were obtained by cystocentesis from 40 clinically healthy cats, and pH was measured within 2 hours of collection. Each sample was evaluated using pH paper, urinalysis reagent strip, 2 brands of portable pH meters (Chek-Mite, Corning, Corning, NY, USA; and Checker 1, Hanna Instruments, Woonsocket, RI, USA), and a standard laboratory benchtop pH meter. Urine samples were refrigerated, and a second pH reading was obtained with the laboratory benchtop meter after 24 hours. The degree of agreement was assessed among the different methods, with the laboratory benchtop pH meter as the reference method.
RESULTS
The closest agreement was obtained with the Chek-Mite portable pH meter and least agreement with the Checker 1 portable pH meter, which had a constant negative bias of 0.31 units due to expiration of the electrode. As expected, pH paper and reagent strips had poor and intermediate agreement, respectively. The reagent strip method had a negative bias of 0.12 units when compared with the benchtop pH meter and wide disagreement at the low pH end. The reagent strip did not agree strongly with the reference method; only 50% of values were within 0.25 pH units of each other. The difference in pH between 0 hours (6.57 +/- 0.54) and 24 hours of refrigeration (6.61 +/- 0.53) was not considered clinically significant.
CONCLUSION
Portable pH meters are excellent for monitoring urine pH at home as long as attention is given to electrode maintenance. Urine can be collected at home and kept refrigerated, and pH may be measured reliably within 24 hours using the reference method or a portable pH meter.
Topics: Animals; Cat Diseases; Cats; Hydrogen-Ion Concentration; Monitoring, Physiologic; Reagent Strips; Refrigeration; Urinalysis; Urinary Calculi
PubMed: 12040484
DOI: 10.1111/j.1939-165x.2002.tb00279.x -
Diabetic Medicine : a Journal of the... Jun 1994A study was conducted to assess the effect of changes in sample pH and pO2 on the Accutrend, ExacTech Companion, Glucometer II, One Touch II, and Refloflux II blood...
A study was conducted to assess the effect of changes in sample pH and pO2 on the Accutrend, ExacTech Companion, Glucometer II, One Touch II, and Refloflux II blood glucose meters. Venous blood was tonometered after the addition of strong acid or alkali to produce 10 samples with a pH range of 6.54 to 7.73 but with a similar mean pO2 (9.09 +/- 0.096 (SEM) kPa) and pCO2 (5.52 +/- 0.024 kPa). The ExacTech showed a > 15% deviation from the value obtained at pH 7.40 below pH 6.95 and above pH 7.85 (r = 0.69, p = 0.026). Ten further samples were made with a pO2 range of 2.0 to 33.6 kPa but mean pH (7.28 +/- 0.012) and pCO2 (7.98 +/- 0.25 kPa) kept alike. The ExacTech was accurate at pO2 = 11.5 kPa but deviated by > 15% below pO2 = 5.8 kPa and above 22.9 kPa (r = -0.95, p = 0.00002). The Accutrend and One Touch II required a pO2 change of 42 and 45 kPa to achieve the same error (r = -0.82 and r = -0.67 respectively). Thus caution is required in the interpretation of ExacTech glucose measurements in severely acidotic or hypoxic patients.
Topics: Blood Glucose; Blood Glucose Self-Monitoring; Humans; Hydrogen-Ion Concentration; Linear Models; Oxygen
PubMed: 8088132
DOI: 10.1111/j.1464-5491.1994.tb00315.x -
Sensors (Basel, Switzerland) May 2017Currently, Cystic Fibrosis (CF) patients lack the ability to track their lung health at home, relying instead on doctor checkups leading to delayed treatment and lung...
Currently, Cystic Fibrosis (CF) patients lack the ability to track their lung health at home, relying instead on doctor checkups leading to delayed treatment and lung damage. By leveraging the ubiquity of the smartphone to lower costs and increase portability, a smartphone-based peripheral pH measurement device was designed to attach directly to the headphone port to harvest power and communicate with a smartphone application. This platform was tested using prepared pH buffers and sputum samples from CF patients. The system matches within ~0.03 pH of a benchtop pH meter while fully powering itself and communicating with a Samsung Galaxy S3 smartphone paired with either a glass or Iridium Oxide (IrOx) electrode. The IrOx electrodes were found to have 25% higher sensitivity than the glass probes at the expense of larger drift and matrix sensitivity that can be addressed with proper calibration. The smartphone-based platform has been demonstrated as a portable replacement for laboratory pH meters, and supports both highly robust glass probes and the sensitive and miniature IrOx electrodes with calibration. This tool can enable more frequent pH sputum tracking for CF patients to help detect the onset of pulmonary exacerbation to provide timely and appropriate treatment before serious damage occurs.
Topics: Cystic Fibrosis; Electrodes; Humans; Lung; Smartphone
PubMed: 28556804
DOI: 10.3390/s17061245 -
Journal of Diabetes Science and... May 2020When used in hospital settings, glucose meter performance issues involve analytic comparability to lab-based testing, patient and sample variables, and clinical affects... (Review)
Review
When used in hospital settings, glucose meter performance issues involve analytic comparability to lab-based testing, patient and sample variables, and clinical affects such as insulin treatment protocol outcomes and morbidity or outcome risk factors. Different tools are available to assess these issues, including accuracy and precision statistics along with clinical risk measures such as error grids or simulation testing. Regulatory, guidance, and professional bodies have advocated a number of varying recommendations for glucose meter performance in different situations and under different patient conditions. These are summarized and compared, but reconciling these guidelines can be confusing or difficult for providers. Blood glucose meters are useful in the management of patients in acute or assisted care facilities, but users must appreciate the variables that affect measurements and provide for oversight that can manage risk factors and maintain meter performance expectations.
Topics: Biomarkers; Blood Chemical Analysis; Blood Glucose; Equipment Design; Guideline Adherence; Hospitals; Humans; Point-of-Care Systems; Point-of-Care Testing; Practice Guidelines as Topic; Predictive Value of Tests; Reproducibility of Results
PubMed: 31983225
DOI: 10.1177/1932296819898277 -
Environmental Monitoring and Assessment Jan 2023Water quality monitoring allows communities to achieve sustainable management of water resources, which is crucial for life-supporting processes. Water quality is...
Water quality monitoring allows communities to achieve sustainable management of water resources, which is crucial for life-supporting processes. Water quality is determined by measuring chemical, physical, and biological parameters, requiring sophisticated meters and trained specialists to perform the measurement. However, in low-income communities, water quality is determined by using human senses-smell, color, and taste-since meter acquisition is limited by costs and most people do not know how to monitor water quality. Therefore, accessible technology is necessary to empower communities to have a sustainable lifestyle. In this paper, we present the design and implementation of PortAqua, a 2-parameter water quality meter (WQM), to promote training on water quality measurement. Using basic electronic components, PortAqua is capable of measuring pH with an error of 0.4, and conductivity with an error of 33% at 85 µS cm, and 8.7% at 1413 µS cm. To demonstrate its preliminary effectiveness as a WQM and its science communication capabilities, the meter has been used in a hands-on workshop with undergraduate and graduate students. During the workshop, attendees participated in a short lecture about water quality measurement techniques and local regulations. Then, they collected water samples from a local source, measured the samples using PortAqua, and discussed the results based on the concepts and regulations. The workshop's effectiveness was evaluated through pre- and post-assessments which revealed increased knowledge of water quality regulations, measurement, and parameters at the end of the activity.
Topics: Humans; Water Quality; Environmental Monitoring; Students; Communication
PubMed: 36705766
DOI: 10.1007/s10661-022-10804-3 -
Journal of the American Veterinary... Feb 2007To evaluate the reproducibility and accuracy of 4 portable pH meters, a reagent strip, and pH paper for measuring urine pH in dogs. (Randomized Controlled Trial)
Randomized Controlled Trial
OBJECTIVE
To evaluate the reproducibility and accuracy of 4 portable pH meters, a reagent strip, and pH paper for measuring urine pH in dogs.
DESIGN
Prospective masked randomized study.
SAMPLE POPULATION
201 free-catch urine samples from 114 hospitalized dogs.
PROCEDURES
Urine samples were divided into 2-mL aliquots. Measurements of urine pH were obtained by use of a laboratory benchtop pH meter, 4 portable pH meters, a urine reagent strip, and pH paper. The pH of each aliquot was measured within 4 hours of collection by an evaluator unaware of the aliquot's origin. To assess reproducibility, the coefficient of variation for each pH measurement device was calculated. To determine which device was most accurate, the degree of agreement among the different devices was assessed in comparison with the benchtop pH meter, which was considered the reference method.
RESULTS
3 of the 4 portable pH meters had nearly perfect agreement with the reference method. The reagent strip and pH paper had moderate to poor agreement with the reference method.
CONCLUSIONS AND CLINICAL RELEVANCE
Urine pH measurements should be made by use of a portable or benchtop pH meter when accurate measurements are crucial for diagnosis or treatment. Reagent strips and pH papers are useful in obtaining pH approximations but are not recommended when accurate measurements of urine pH are required.
Topics: Animals; Clinical Laboratory Techniques; Dog Diseases; Dogs; Hydrogen-Ion Concentration; Prospective Studies; Reagent Strips; Reproducibility of Results; Sensitivity and Specificity; Urinalysis; Urine
PubMed: 17269867
DOI: 10.2460/javma.230.3.364 -
Analytical Chemistry Aug 2018In this work, a self-powered, portable, and light-addressable photoelectrochemical sensor (P-LAPECS) is developed for efficient drug screening using a handheld pH meter...
In this work, a self-powered, portable, and light-addressable photoelectrochemical sensor (P-LAPECS) is developed for efficient drug screening using a handheld pH meter readout. The sensor, which employs thrombin inhibitors as the drug model, is constructed by evenly immobilizing biotin-labeled and thrombin-cleavable peptides on eight separated sensing zones of a single gold film electrode. The incubation of each peptide sensing zone with thrombin leads to the reduction of binding sites for streptavidin-labeled fullerene (C) PEC bioprobes, which directly reflects the activity of thrombin by the variation of both photocurrent and photovoltage, and therefore allows the screening of thrombin inhibitors using either a single-channel electrochemical analyzer or a portable pH meter. Consequenty, the inhibition efficiency evaluation of multiple thrombin inhibitors can be achieved by just one electrode, and the screening result obtained by the pH meter is very close to that acquired by the electrochemical analyzer. Moreover, P-LAPECS can realize the light-addressable detection of thrombin with a detection limit as low as 0.05 pM. The present work thus demonstrates the possibility of constructing portable, inexpensive, sensitive, and high-throughput biosensing platforms using ubiquitous pH meters for laboratories all over the world.
Topics: Antithrombins; Electrochemical Techniques; Fullerenes; High-Throughput Screening Assays; Hydrogen-Ion Concentration; Light; Limit of Detection; Microscopy, Electron, Scanning; Photochemical Processes; Streptavidin
PubMed: 29998727
DOI: 10.1021/acs.analchem.8b01979 -
Pediatric Research Mar 2021Transcutaneous bilirubinometry is a widely used screening method for neonatal hyperbilirubinemia. Deviation of the transcutaneous bilirubin concentration (TcB) from the...
BACKGROUND
Transcutaneous bilirubinometry is a widely used screening method for neonatal hyperbilirubinemia. Deviation of the transcutaneous bilirubin concentration (TcB) from the total serum bilirubin concentration (TSB) is often ascribed to biological variation between patients, but variations between TcB meters may also have a role. This study aims to provide a systematic evaluation of the inter-device reproducibility of TcB meters.
MATERIALS AND METHODS
Thirteen commercially available TcB meters (JM-105 and JM-103) were evaluated in vitro on phantoms that optically mimic neonatal skin. The mimicked TcB was varied within the clinical range (0.5-181.3 μmol/L).
RESULTS
Absolute differences between TcB meter outcomes increased with the measured TcB, from a difference of 5.0 μmol/L (TcB = 0.5 μmol/L phantom) up to 65.0 μmol/L (TcB = 181.3 μmol/L phantom).
CONCLUSION
The inter-device reproducibility of the examined TcB meters is substantial and exceeds the specified accuracy of the device (±25.5 μmol/L), as well as the clinically used TcB safety margins (>50 µmol/L below phototherapy threshold). Healthcare providers should be well aware of this additional uncertainty in the TcB determination, especially when multiple TcB meters are employed in the same clinic. We strongly advise using a single TcB meter per patient to evaluate the TcB over time.
IMPACT
Key message: The inter-device reproducibility of TcB meters is substantial and exceeds the clinically used TcB safety margins. What this study adds to existing literature: The inter-device reproducibility of transcutaneous bilirubin (TcB) meters has not been reported in the existing literature. This in vitro study systematically evaluates this inter-device reproducibility.
IMPACT
This study aids in a better interpretation of the measured TcB value from a patient and is of particular importance during patient monitoring when using multiple TcB meters within the same clinical department. We strongly advise using a single TcB meter per patient to evaluate the TcB over time.
Topics: Bilirubin; Diagnostic Tests, Routine; Equipment Design; Humans; Hyperbilirubinemia, Neonatal; Infant, Newborn; Infant, Newborn, Diseases; Infant, Premature; Monitoring, Physiologic; Neonatal Screening; Phantoms, Imaging; Reproducibility of Results; Skin Physiological Phenomena
PubMed: 32919392
DOI: 10.1038/s41390-020-01118-6 -
The New Zealand Medical Journal Nov 2013Health consumer's input into assessment of medical device safety is traditionally given either as part of study outcome (trial participants) or during post marketing... (Review)
Review
Health consumer's input into assessment of medical device safety is traditionally given either as part of study outcome (trial participants) or during post marketing surveillance. Direct consumer input into the methodological design of device assessment is less common. We discuss the difference in requirements for assessment of a measuring device from the consumer and clinician perspectives, using the example of hand held glucose meters. Around 80,000 New Zealanders with diabetes recently changed their glucose meter system, to enable ongoing access to PHARMAC subsidised meters and strips. Consumers were most interested in a direct comparison of their 'old' meter system (Accu-Chek Performa) with their 'new' meter system (CareSens brand, including the CareSens N POP), rather than comparisons against a laboratory standard. This direct comparison of meter/strip systems showed that the CareSens N POP meter read around 0.6 mmol/L higher than the Performa system. Whilst this difference is unlikely to result in major errors in clinical decision making such as major insulin dosing errors, this information is nevertheless of interest to consumers who switched meters so that they could maintain access to PHARMAC subsidised meters and strips. We recommend that when practical, the consumer perspective be incorporated into study design related to medical device assessment.
Topics: Blood Glucose; Blood Glucose Self-Monitoring; Diabetes Mellitus; Equipment Design; Humans; Point-of-Care Systems; Reproducibility of Results
PubMed: 24316996
DOI: No ID Found