Short-Term Thermal-Humidity Shock Affects Point-of-Care Glucose Testing: Implications for Health Professionals and Patients

Spectrochip-based Calibration Curve Modeling (CCM) for Rapid and Accurate Multiple Analytes Quantification in Urinalysis

Most urine test strips are intended to enable the general population to rapidly and easily diagnose potential renal disorders. It is semi-quantitative in nature, and although the procedure is straightforward, certain factors will affect the judgmental outcomes. This study describes rapid and accurate quantification of twelve urine test strip parameters: leukocytes, nitrite, urobilinogen, protein, pH, occult blood, specific gravity, ketone, bilirubin, glucose, microalbumin, and creatinine using a micro-electromechanical system (MEMS)-based spectrophotometer, known as a spectrochip. For each parameter, absorption spectra were measured three times independently at eight different concentration levels of diluted standard solutions, and the average spectral intensities were calculated to establish the calibration curve under the characteristic wavelength (λ c ). Then, regression analysis on the calibration curve was performed with GraphPad Prism software, which revealed that the coefficient of determination (R 2 ) of the modeled calibration curves was greater than 0.95. This result illustrates that the measurements exceed standard levels, confirming the importance of a spectrochip for routine multi-parameter urine analysis. Thus, it is possible to obtain the spectral signal strength for each parameter at its characteristic wavelength in order to compare directly with the calibration curves in the future, even in situations when sample concentration is unknown. Additionally, the use of large testing machines can be reduced in terms of cost, time, and space by adopting a micro urine testing platform based on spectrochip, which also improves operational convenience and effectively enables point-of-care (POC) testing in urinalysis.

Using geographic rescue time contours, point-of-care strategies, and spatial care paths to prepare island communities for global warming, rising oceans, and weather disasters

OBJECTIVES

To perform geographic contour analysis of sea and land ambulance rescue times in an archipelago subject to super typhoons; to design point-of-care testing strategies for medical emergencies and weather disasters made more intense by global warming and rising oceans; and to assess needs for prehospital testing on spatial care paths that accelerate decision making, increase efficiency, improve outcomes, and enhance standards of care in island nations.

METHODS

We performed needs assessments, inspected healthcare facilities, and collected ambulance rescue times from professionals in the Bantayan Archipelago, Philippines. We mapped sea/land ambulance rescue routes and time contours. To reveal gaps, we statistically compared the fastest and slowest patient rescue times from islands/islets and barangays to the District Hospital on Bantayan Island. We developed spatial care paths (the fastest routes to care) for acute myocardial infarction, community care, and infectious diseases. We generated a compendium of prehospital diagnostic testing and integrated outcomes evidence, diagnostic needs, and public health goals to recommend point-of-care strategies that build geographic health resilience.

RESULTS

We observed limited access to COVID-19 assays, absence of blood gas/pH testing for critical care support, and spatial gaps in land and airborne rescues that worsened during inclement weather and sea swells. Mean paired differences (slowest-fastest) in ambulance rescue times to the District Hospital for both islands and barangays were significant (P < 0.0001). Spatial care path analysis showed where point-of-care cardiac troponin testing should be implemented for expedited care of acute myocardial infarction. Geospatial strengths comprised distributed primary care that can be facilitated by point-of-care testing, logical interisland transfers for which decision making and triage could be accelerated with onboard diagnostics, and healthcare networks amenable to medical advances in prehospital testing that accelerate treatment.

CONCLUSIONS

Point-of-care testing should be positioned upstream close to homes and island populations that have prolonged rescue time contours. Geospatially optimized point-of-need diagnostics and distributed prehospital testing have high potential to improve outcomes. These improvements will potentially decrease disparities in mortality among archipelago versus urban dwellers, help improve island public health, and enhance resilience for increasingly adverse and frequent climate change weather disasters that impact vulnerable coastal areas. [350 words].

Effects of Simulated Adverse Environmental Conditions Related to Actual Conditions at Health Promoting Hospitals on the Performance of Blood Glucose Testing by Glucose Meters

BACKGROUND

Annual peaks in temperature and humidity exceed manufacturers' specifications for blood glucose test strip storage in Thailand. Health Promoting Hospitals (HPH) do not always provide the same level of health services that hospitals do since they often only turn on air-conditioning units during working hours.

METHODS

The blood glucose testing performance of 4 glucose meters were investigated for short and long terms stress at 5 simulated conditions. Temperature and relative humidity (RH) at 5 HPHs in different regions of Thailand were monitored for 9 weeks during April to July 2019. The use of air conditioning in storage rooms for storing test strips was surveyed at 131 HPHs using questionnaires.

RESULTS

Median-paired differences of glucose measurements with stressed test strips in 5 simulated conditions significantly differed (P < 0.05) both in the short term (3 days) and in the long term (30 days) with 4 glucose meters when compared to unstressed test strips. The average temperature of all HPHs exceeded 30°C (86°F). The average RH was 84%. There was only one HPH that occasionally turned on its air conditioners. Most HPHs kept both opened and unopened vials of test strips in rooms without air conditioners. Further, 21.4-32.0% of HPHs kept test strips at room with air conditioners.

CONCLUSIONS

This study provides evidence for poor performance of blood glucose testing by glucose meters that are affected by adverse environmental conditions. The environmental for test strips storage at HPHs should be considered to prevent analytical errors of glucose measurement.

A review of temperature-related challenges and solutions for the Abbott i-STAT and Siemens Healthineers epoc devices

The Abbott i-STAT and Siemens Healthineers epoc are commonly used in the provision of care during emergency medical services calls and other settings. Maintaining these systems within manufacturer's temperature claims in these settings poses challenges across the world. This review summarizes solutions that have been reported in the peer-reviewed literature and proposes additional strategies to further address these challenges. A literature search was performed with Clarivate's Web of Science from inception to August 3, 2022. Search terms included i-STAT, epoc, temperature, cold, hot, heat, freeze, frozen, prehospital, disaster, POCT, point of care, blood gas, helicopter, airplane, and ambulance. One author also reviewed manually every issue of the Journal of Paramedic Practice. The search identified 17 solutions for addressing temperature-related challenges with the i-STAT device, nine solutions for i-STAT cartridges, one solution for the epoc device, and one solution for the epoc test card. The majority of solutions were highly portable and consisted of widely available, inexpensive components. The solutions demonstrated only partial or entirely questionable effectiveness in achieving temperature control. The search also identified five reports on the impact of storage temperatures on cartridges and test cards. The reports suggested that these reagents may be able to withstand storage at temperatures outside of manufacturer's claims with only minimal deterioration in performance. The heterogeneity of solutions and the paucity of evidence on their effectiveness suggest that additional strategies are needed to better understand and further address temperature-related challenges with these systems. A collaborative approach and shared decision making are recommended.

Clinical Study of a High Accuracy Green Design Blood Glucose Monitor Using an Innovative Optical Transmission Absorbance System

BACKGROUND

Blood glucose monitoring (BGM) is essential for glycemic control in diabetic therapy. Followingly, accurate sensors are required for both daily personal and clinical use. The frequency of sensor use in patients with diabetes facilitates the use of disposable components. However, BGM systems are not exempt from green innovation sustainability initiatives.

METHODS

Clinical study of a high-accuracy green design blood glucose monitor using an innovative optical transmission absorbance system was carried out. Venous blood samples were collected from 104 patients with type II diabetes. The heat resistance of sensor strips was evaluated by storing sensor strips at 25℃ and 60℃ for approximately 3 months. Accuracy of the BGM system was evaluated via the ISO 15197:2013 protocol.

RESULTS

The BGM system achieved ±7.1% accuracy in glycemic level measurement, with 84% of all measurements within ±5% of the reference values. Furthermore, the sensor strip demonstrated heat resistance for more than 3 months when stored at 60℃.

CONCLUSIONS

A new, highly accurate BGM system was developed based on the latest optical measurement system, introducing a rare metal-free "green-strip." The developed BGM system achieved the highest reported accuracy in clinical research, using venous blood from patients with diabetes. The sensor strip also exhibited high heat resistance, reducing limitations on storage conditions.

Point-of-Care Testing Practices, Failure Modes, and Risk-Mitigation Strategies in Emergency Medical Services Programs in the Canadian Province of Alberta

CONTEXT.—

Emergency medical services (EMS) programs have been using point-of-care testing (POCT) for more than 20 years. However, only a handful of reports have been published in all of that time on POCT practices in field settings.

OBJECTIVE.—

To provide an overview of POCT practices and failure modes in 3 of Alberta's EMS programs, and to propose risk-mitigation strategies for reducing or eliminating these failure modes.

DESIGN.—

Details about POCT practices, failure modes, and risk-mitigation strategies were gathered through (1) conversations with personnel, (2) in-person tours of EMS bases, (3) accompaniment of EMS personnel on missions, (4) internet searches for publicly available information, and (5) a review of laboratory documents.

RESULTS.—

Practices were most standardized and robust in the community paramedicine program (single service provider, full laboratory oversight), and least standardized and robust in the air ambulance program (4 service providers, limited laboratory oversight). Common failure modes across all 3 programs included device inoperability due to cold weather, analytical validation procedures that failed to consider the unique challenges of EMS settings, and a lack of real-time electronic transmission of results into the health care record.

CONCLUSIONS.—

A provincial framework for POCT in EMS programs is desirable. Such a framework should include appropriate funding models, laboratory oversight of POCT, and relevant expertise on POCT in EMS settings. The framework should also incorporate specific guidance on quality standards that are needed to address the unique challenges of performing POCT in field settings.

Low-Cost Thermal Shield for Rapid Diagnostic Tests Using Phase Change Materials

The shelf life of point-of-care and rapid diagnostic tests (POC-RDTs) is commonly compromised by abrupt temperature changes during storage, transportation, and use. This situation is especially relevant in tropical regions and resource-constrained settings where cold chain may be unreliable. Here, we report the use of novel and low-cost passive thermal shield (TS) made from laminated phase change material (PCM) to reduce thermal overload in POC-RDTs. Validation of the proposed design was done through numerical simulation and testing of an octadecane shield prototype in contact with a lateral flow immunoassay. The use of our TS design provided 30–45 min delay in thermal equilibration under constant and oscillating heat load challenges resembling those of field use. The addition of a thin PCM protection layer to POC-RDTs can be a cost-effective, scalable, and reliable solution to provide additional thermal stability to these devices.

Wearable Microsystem for Minimally Invasive, Pseudo-Continuous Blood Glucose Monitoring: The e-Mosquito

This paper presents a wearable microsystem for minimally invasive, autonomous, and pseudo-continuous blood glucose monitoring, addressing a growing demand for replacing tedious fingerpricking tests for diabetic patients. Unlike prevalent solutions which estimate blood glucose levels from interstitial fluids or tears, our design extracts a whole blood sample from a small lanced skin wound using a novel shape memory alloy (SMA)-based microactuator and directly measures the blood glucose level from the sample. In vitro characterization determined that the SMA microactuator produced penetration force of 225 gf, penetration depth of 3.55 mm, and consumed approximately 5.56 mW·h for triggering. The microactuation mechanism was also evaluated by extracting blood samples from the wrist of four human volunteers. A total of 19 out of 23 actuations successfully reached capillary vessels below the wrists producing blood droplets on the surface of the skin. The integrated potentiostat-based glucose sensing circuit of our e-Mosquito device also showed a good linear correlation (R² = 0.9733) with measurements using standard blood glucose monitoring technology. These proof-of-concept studies demonstrate the feasibility of the e-Mosquito microsystem for autonomous intermittent blood glucose monitoring.

Interferences and Limitations in Blood Glucose Self-Testing: An Overview of the Current Knowledge

In general, patients with diabetes performing self-monitoring of blood glucose (SMBG) can strongly rely on the accuracy of measurement results. However, various factors such as application errors, extreme environmental conditions, extreme hematocrit values, or medication interferences may potentially falsify blood glucose readings. Incorrect blood glucose readings may lead to treatment errors, for example, incorrect insulin dosing. Therefore, the diabetes team as well as the patients should be well informed about limitations in blood glucose testing. The aim of this publication is to review the current knowledge on limitations and interferences in blood glucose testing with the perspective of their clinical relevance.

The Effects of Temperature and Relative Humidity on Point-of-Care Glucose Measurements in Hospital Practice in a Tropical Clinical Setting

BACKGROUND

Hospitals in tropical countries experience conditions that exceed manufacturer temperature and humidity limits for point-of-care (POC) glucose reagents. Our goal was to assess the effects of out-of-limits storage temperature, operating temperature, and operating humidity on POC glucose measurement reliability.

METHODS

Quality control measurements were performed monthly using glucose test strips stored under controlled conditions and in inpatient wards under ambient conditions. Glucose test strips were evaluated in groups organized by operating temperatures of 24-25 (group 1), 28-29 (group 2), and 33-34°C (group 3), and relative humidity (RH) of ≤70 (group A), ~80 (group B), and ~90% (group C).

RESULTS

Glucose results for different storage conditions were inconsistent. Measurements at higher operating temperatures had lower values with mean differences of -2.4 (P < .001) and -36.5 (P < .001) mg/dL (28-29 vs 24-25°C), and -3.6 (P < .001) and -37.4 (P < .001) mg/dL (33-34 vs 24-25°C) for low and high control levels, respectively. Measurements at higher RH had lower values with mean differences of -4.0 (P < .001) and -13.2 (P < .001) mg/dL (~80 vs ≤70% RH), and -5.8 (P < .001) and -16.6 (P < .001) mg/dL (~90 vs ≤70% RH) for low and high levels, respectively.

CONCLUSIONS

High temperature and high RH decreased glucose concentrations for the POC oxidase-based system we evaluated. We recommend that individual hospitals perform stress testing, then determine if maximum absolute differences, which represent highest risk for patients, are clinically significant for decision making by using error grid analysis.

Multicentric evaluation of eight glucose and four ketone blood meters

OBJECTIVES

High precision meters for blood glycemia are mandatory for monitoring glucose status in patients, avoiding both hypo- and hyper-glycemia. Health care providers routinely used in both out- and in-patients point-of-care measurements of glucose and ketone. These measurements, frequently used for medical decisions, are known to be less accurate than those performed in laboratories. Our aim was to evaluate, within the frame of an Assistance Publique-Hôpitaux de Paris (AP-HP) multicentric study, the performances of eight glucose and four ketone meters, either connected or non-connected to a laboratory software.

DESIGN AND METHODS

Glucose meter accuracy, precision, correlation with plasma glucose determined in central laboratories and hematocrit interferences were determined according to the ISO 15197:2003 norm. The same norm was applied for the determination of accuracy, precision and recovery of ketone meters for B-hydroxybutyrate measurements.

RESULTS AND CONCLUSION

Among those meters, seven were considered as acceptable for glucose measurement and two for ketone measurement. Since all meters do not fit clinically relevant criteria, meters' performances have to be evaluated before use in clinical practice.

Computing the surveillance error grid analysis: procedure and examples

The surveillance error grid (SEG) analysis is a tool for analysis and visualization of blood glucose monitoring (BGM) errors, based on the opinions of 206 diabetes clinicians who rated 4 distinct treatment scenarios. Resulting from this large-scale inquiry is a matrix of 337 561 risk ratings, 1 for each pair of (reference, BGM) readings ranging from 20 to 580 mg/dl. The computation of the SEG is therefore complex and in need of automation. The SEG software introduced in this article automates the task of assigning a degree of risk to each data point for a set of measured and reference blood glucose values so that the data can be distributed into 8 risk zones. The software's 2 main purposes are to (1) distribute a set of BG Monitor data into 8 risk zones ranging from none to extreme and (2) present the data in a color coded display to promote visualization. Besides aggregating the data into 8 zones corresponding to levels of risk, the SEG computes the number and percentage of data pairs in each zone and the number/percentage of data pairs above/below the diagonal line in each zone, which are associated with BGM errors creating risks for hypo- or hyperglycemia, respectively. To illustrate the action of the SEG software we first present computer-simulated data stratified along error levels defined by ISO 15197:2013. This allows the SEG to be linked to this established standard. Further illustration of the SEG procedure is done with a series of previously published data, which reflect the performance of BGM devices and test strips under various environmental conditions. We conclude that the SEG software is a useful addition to the SEG analysis presented in this journal, developed to assess the magnitude of clinical risk from analytically inaccurate data in a variety of high-impact situations such as intensive care and disaster settings.