Blood glucose testing in the hospital: error sources and risk management

Potential use of Six Sigma metrics in the quality control review of hospital glucose meters

Background and aim

This study applied Six Sigma metrics to facilitate the quality control (QC) review for hospital glucose meters.

Materials and methods

QC data from a period of six months on all hospital glucose meters were extracted from the data management system. Sigma values for each meter at two QC levels were calculated and evaluated each month by combining the imprecision, the absolute bias between the meter mean and all-meter mean, and the standards from ISO 15179:2013. The effectiveness of using Sigma values in identifying meters with possible quality problems for further Levey-Jennings QC chart review was assessed.

Results

More than 80 % of the meter's Sigma values within the six months were greater than 4 at either QC level. At the high QC level, twice as many Sigma values were below 4 than the low QC level. Including Sigma values 4, 3.5 or 3 in the criteria for the QC review reduced the number of chart review to 32.8 %, 11.2 % or 3.5 %, respectively.

Conclusions

The majority of the glucose meters examined in this study demonstrated optimal Sigma values. The Sigma metrics-based approach could be a valuable tool to guide an effective QC review of glucose meters for quality improvement.

Accuracy of point-of-care capillary blood sugar measurements in critically ill patients: An observational study

Background

Accurately monitoring blood glucose levels is vital for critically ill individuals. Point-of-care (POC) glucose meters are commonly used in local intensive care units (ICUs). This study aimed to assess the precision of POC glucose meter readings in critically ill individuals with specific evaluation in patients with and without shock against the reference standard of venous blood glucose measurements.

Methods

An observational study was done on adult patients admitted in the ICU at a teaching institution. Capillary blood samples were collected from the patient's fingertip using lancet device with aseptic measures. The sample was analyzed using the GlucoCare Sense Glucometer (RMD Mediaids Limited, Taiwan). At the same time, 2 ml of blood was drawn from the patient's peripheral veins and analyzed by glucose oxidase-peroxidase method as reference.

Results

POC glucose measurements averaged 140 ± 20.23 mg/dl, while laboratory values were recorded as 116.10 ± 17.13 mg/dl. The difference between the two methods was 24.34 ± 12.01 mg/dl. A strong correlation (r = 0.805) was found between capillary and laboratory blood glucose levels, indicating a significant association (P < 0.0001). Twenty-two (44%) patients were in shock during the study. The mean difference between laboratory and POC blood glucose levels was higher in patients with circulatory shock (36.82 ± 4.84 mg/dl) than those without shock (14.61 ± 4.49 mg/dl), P < 0.05.

Conclusion

POC glucose meters may lead to underdetection of hypoglycemia in critically ill patients, as their values are higher than laboratory values. Moreover, the results showed that POC glucometers are inaccurate for monitoring glucose in hypotensive patients in shock. Standard venous glucose monitoring methods may be more appropriate for these patients.

Cardiac troponin measurement at the point of care: educational recommendations on analytical and clinical aspects by the IFCC Committee on Clinical Applications of Cardiac Bio-Markers (IFCC C-CB)

The International Federation of Clinical Chemistry and Laboarator Medicine (IFCC) Committee on Clinical Applications of Cardiac Bio-Markers (C-CB) has provided evidence-based educational resources to aid and improve the understanding of important analytical and clinical aspects of cardiac biomarkers. The present IFCC C-CB educational report focuses on recommendations for appropriate use, analytical performance, and gaps in clinical studies related to the use of cardiac troponin (cTn) by point of care (POC) measurement, often referred to as a point of care testing (POCT). The use of high-sensitivity (hs)-cTn POC devices in accelerated diagnostic protocols used in emergency departments or outpatient clinics investigating acute coronary syndrome has the potential for improved efficacy, reduction of length of stay and reduced costs in the health care system. POCT workflow integration includes location of the instrument, assignment of collection and testing responsibility to (non-lab) staff, instrument maintenance, in-service and recurrent training, quality control, proficiency assessments, discrepant result trapping, and troubleshooting and inventory management.

Point-of-care testing in primary healthcare: a scoring system to determine the frequency of performing internal quality control

OBJECTIVES

Internal quality control (IQC) plays an important role in quality assurance in laboratory medicine. However, there is no universal consensus or guideline on when and how IQC should be analyzed on point-of-care testing (POCT) devices. The aim of this study was to develop a scoring system to determine how often IQC should be analyzed in primary healthcare on the various POCT devices.

METHODS

Based on a systematic literature review and a thorough process involving the whole Noklus, a nationwide POC organization, a scoring system for when to analyze IQC was developed. Four factors were considered to significantly impact IQC frequency: The importance of the analyte in diagnosing and monitoring patients, type of POCT device, user-friendliness, and number of patient samples. For each POCT device, the first three factors were given a score, and the sum of the scores determined the general recommended IQC frequency. The number of patient samples determined whether and how to adjust these frequencies in each individual general practice.

RESULTS

The scoring system was applied to 17 analytes and 134 different POCT devices (153 analyte-device combinations). Most of the devices analyzing high-risk analytes (71 out of 74) obtained daily or weekly IQC frequency. For example, all blood-cell counters and all glucose meters should undergo IQC daily and weekly, respectively.

CONCLUSIONS

This study presents a consensus-based scoring system for differentiated and device-specific recommendations for IQC frequency on POCT devices in primary healthcare. The scoring system can easily be adopted to other local environments and is easy to use.

Connectivity Strategies in Managing a POCT Service

Point of Care Testing is increasingly being used for diagnosis and management of various disease states. Management of different Point of Care instruments at multiple sites can be challenging, particularly when such instruments are operated by non technical staff. Connectivity is critical for optimal management of these services which are intimately linked to operator training and competency and are important in minimising harm to the patient by reducing analytical errors. Furthermore, connectivity improves turn around time leading to faster decision making by physicians. Recent advances in technology such as 5G and artificial intelligence are likely to lead to a greater focus on personalized care as a result of big data analysis and development of algorithms.

Six Sigma performance of quality indicators in total testing process of point-of-care glucose measurement: A two-year review

Objectives

The error rate in the total testing process (TTP) of point-of-care (POC) glucose measurement remains high although a total quality management system has been applied. Quality indicators (QIs) in the TTP of glucose meter were established via risk assessment. Their two-year Six Sigma values were reviewed for quality improvement.

Design

The TTP of POC glucose measurement was mapped to identify risks in key steps. The risks were assessed for their frequency and severity of impact on patient safety. Whenever possible, measurable data from the data management system and other sources was collected to establish QIs for risk monitoring. Average Six Sigma value of each QI in the last two years was calculated for acceptance and for determining corrective action.

Results

29 risks were identified in eight key steps of the TTP. Eight QIs were established for monitoring six risks and three QIs for two accepted risks were established for improving operator testing skill. The QIs had a good coverage to key steps. Two, five and four QIs showed Six Sigma values <3, 3-4 and >4 respectively. Six Sigma values of two QIs related to quality control (QC) testing were improved by using meters with accurate QC sample loading.

Conclusions

The establishment of QIs for glucose measurement by risk assessment with measurable data from the data management system and on Six sigma scale was effective, efficient, and manageable. Most of QIs’ Six Sigma values were between 3 and 5, which could be improved by using upgraded meters.

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The total testing process of POC glucose measurement was assessed to identify all risks that might impact patient safety.

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QIs that established from data management system monitored the risks related to all of the meters and operators.

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Six Sigma values of QIs provided a straightforward acceptance in their performance evaluation.

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Most of the Six Sigma values of QIs for glucose meters were between 3 and 5 under current total quality management system.

LabWAS: Novel findings and study design recommendations from a meta-analysis of clinical labs in two independent biobanks

Phenotypes extracted from Electronic Health Records (EHRs) are increasingly prevalent in genetic studies. EHRs contain hundreds of distinct clinical laboratory test results, providing a trove of health data beyond diagnoses. Such lab data is complex and lacks a ubiquitous coding scheme, making it more challenging than diagnosis data. Here we describe the first large-scale cross-health system genome-wide association study (GWAS) of EHR-based quantitative laboratory-derived phenotypes. We meta-analyzed 70 lab traits matched between the BioVU cohort from the Vanderbilt University Health System and the Michigan Genomics Initiative (MGI) cohort from Michigan Medicine. We show high replication of known association for these traits, validating EHR-based measurements as high-quality phenotypes for genetic analysis. Notably, our analysis provides the first replication for 699 previous GWAS associations across 46 different traits. We discovered 31 novel associations at genome-wide significance for 22 distinct traits, including the first reported associations for two lab-based traits. We replicated 22 of these novel associations in an independent tranche of BioVU samples. The summary statistics for all association tests are freely available to benefit other researchers. Finally, we performed mirrored analyses in BioVU and MGI to assess competing analytic practices for EHR lab traits. We find that using the mean of all available lab measurements provides a robust summary value, but alternate summarizations can improve power in certain circumstances. This study provides a proof-of-principle for cross health system GWAS and is a framework for future studies of quantitative EHR lab traits.

Effective interventions to improve the quality of critically high point-of-care glucose meter results

Objectives

Point-of-care testing (POCT) is testing performed outside the traditional laboratory, often at the patient bedside. In hospital settings, blood glucose is the most common POCT. Staff performing POCT are not usually laboratory trained; they are clinical staff with a primary focus on treating patients. Clinical staff find POCT quality assurance (QA) practices burdensome and are often non-compliant. In hospitals within EORLA (Eastern Ontario Regional Laboratories Association), all critically high POCT glucose results must be repeated prior to acting, according to policy. Compliance with this policy is audited regularly.

Design

and methods: All POCT glucose tests performed in participating sites between January and June 2018 and June and December 2019 were audited for compliance with the critical repeat policy. The discordant repeat rate was also determined for each audit period. Between January and May 2019, there were interventions aimed at improving compliance with the repeat policy.

Results

Compliance with the critical repeat policy increased from 30 to 57% in 2019 compared to 2018, following nursing education and implementation of notifications on the glucose meters themselves. The rate of discordant repeat results (>20% different from initial) also improved at most sites in 2019 compared to 2018. Nurses cited insufficient cleaning of patient hands prior to initial testing as the primary reason for discordant repeats.

Conclusions

Operator compliance with POCT QA policies is an ongoing challenge requiring continual audit, feedback and education. A strong POCT multi-disciplinary committee with supports from senior and clinical leadership in an organization are key to improving compliance.

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Compliance with the policy requiring repeat of all critically high POCT glucose results is audited as a quality indicator.

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Audits demonstrated a high rate of non-compliance with the critical repeat policy by clinical staff performing POCT.

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Approximately 25% of critically high glucose results repeated were discordant (>20% different from the initial result)

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Implementation of meter notifications and nursing education led to significant improvements in compliance at most sites.

The real world of blood glucose point-of-care testing (POCT) system running in China teaching hospital

BACKGROUND

 The blood glucose point-of-care testing (POCT) system is important in the decision-making process involving patients suspected of having hypoglycemia. To investigate the real world of the POCT system being used in teaching hospitals in China.

METHODS

The survey was conducted by Hisend Research Group from May 2015 to July 2015 in four teaching hospitals in China. The survey questions were referred to the ISO 15197:2013 standard requirements for the use of the POCT system in a hospital setting.

RESULTS

A total of 170 subjects were included from 4 hospitals, which included nursing staff, nurse unit managers, employees from the department of medical instruments, and staff members employed by the clinical laboratories in the Tianjin Metabolism Hospital, Nanjing First Hospital, First Affiliated Hospital of Dalian Medical University, and the First hospital affiliated with the Xi'an Transportation University. The average score for the four hospitals surveyed in this study was 66.6, which varied from 46.1 to 79.7. The main factors influencing the scores were the multiple choices of blood-glucose meters, and the quality control assessment.

CONCLUSION

Our data indicates that the real world use of the POCT system in hospital settings in China needs more closer adherence to a quality management framework.

Bridging technology and clinical practice: innovating inpatient hyperglycaemia management in non-critical care settings

Emerging evidence shows that suboptimal glycaemic control is associated with increased morbidity and length of stay in hospital. Various guidelines for safe and effective inpatient glycaemic control in the non-critical care setting have been published. In spite of this, implementation in practice remains limited because of the increasing number of people with diabetes admitted to hospital and staff work burden. The use of technology in the outpatient setting has led to improved glycaemic outcomes and quality of life for people with diabetes. There remains an unmet need for technology utilisation in inpatient hyperglycaemia management in the non-critical care setting. Novel technologies have the potential to provide benefits in diabetes care in hospital by improving efficacy, safety and efficiency. Rapid analysis of glucose measurements by point-of-care devices help facilitate clinical decision-making and therapy adjustment in the hospital setting. Glucose treatment data integration with computerized glucose management systems underpins the effective use of decision support systems and may streamline clinical staff workflow. Continuous glucose monitoring and automation of insulin delivery through closed-loop systems may provide a safe and efficacious tool for hospital staff to manage inpatient hyperglycaemia whilst reducing staff workload. This review summarizes the evidence with regard to technological methods to manage inpatient glycaemic control, their limitations and the future outlook, as well as potential strategies by healthcare organizations such as the National Health Service to mediate the adoption, procurement and use of diabetes technologies in the hospital setting.

Critical Care Glucose Point-of-Care Testing

Maintaining blood glucose concentration within an acceptable range is a goal for patients with diabetes mellitus. Point-of-care glucose meters initially designed for home self-monitoring in patients with diabetes have been widely used in the hospital settings because of ease of use and quick reporting of blood glucose information. They are not only utilized for the general inpatient population but also for critically ill patients. Many factors affect the accuracy of point-of-care glucose testing, particularly in critical care settings. Inaccurate blood glucose information can result in unsafe insulin delivery which causes poor glucose control and can be fatal. Healthcare professionals should be aware of the limitations of point-of-care glucose testing. This chapter will first introduce glucose regulation in diabetes mellitus, hyperglycemia/hypoglycemia in the intensive care unit, importance of glucose control in critical care patients, and pathophysiological variables of critically ill patients that affect the accuracy of point-of-care glucose testing. Then, we will discuss currently available point-of-care glucose meters and preanalytical, analytical, and postanalytical sources of variation and error in point-of-care glucose testing.

Issues in the practical implementation of POCT: overcoming challenges

There are many challenges in implementing a successful point-of-care testing (POCT) program. When compared to traditional testing, POCT results are faster and allow for rapid patient treatment. Unfortunately, the excitement of this technology is often lost due to an assortment of practical obstacles. Implementation of POCT requires consideration of the regulatory complexity and amount of documentation to be compliant. As more tests move to the site of patient care, the number of operators that need to be trained and assessed will grow. An effective POCT program rests solely on the foundation of education and training of each operator, but assuring regular competency updates for a large number of staff can be a management issue. Discussed in this article are several of the key obstacles to implementing a POCT program including laboratory quality regulations, compliance documentation and operational management challenges.

Development and Validation of a Rapid (13)C6-Glucose Isotope Dilution UPLC-MRM Mass Spectrometry Method for Use in Determining System Accuracy and Performance of Blood Glucose Monitoring Devices

BACKGROUND

There is currently considerable discussion about the accuracy of blood glucose concentrations determined by personal blood glucose monitoring systems (BGMS). To date, the FDA has allowed new BGMS to demonstrate accuracy in reference to other glucose measurement systems that use the same or similar enzymatic-based methods to determine glucose concentration. These types of reference measurement procedures are only comparative in nature and are subject to the same potential sources of error in measurement and system perturbations as the device under evaluation. It would be ideal to have a completely orthogonal primary method that could serve as a true standard reference measurement procedure for establishing the accuracy of new BGMS.

METHODS

An isotope-dilution liquid chromatography/mass spectrometry (ID-UPLC-MRM) assay was developed using (13)C6-glucose as a stable isotope analogue to specifically measure glucose concentration in human plasma, and validated for use against NIST standard reference materials, and against fresh isolates of whole blood and plasma into which exogenous glucose had been spiked. Assay performance was quantified to NIST-traceable dry weight measures for both glucose and (13)C6-glucose.

RESULTS

The newly developed assay method was shown to be rapid, highly specific, sensitive, accurate, and precise for measuring plasma glucose levels. The assay displayed sufficient dynamic range and linearity to measure across the range of both normal and diabetic blood glucose levels. Assay performance was measured to within the same uncertainty levels (<1%) as the NIST definitive method for glucose measurement in human serum.

CONCLUSIONS

The newly developed ID UPLC-MRM assay can serve as a validated reference measurement procedure to which new BGMS can be assessed for glucose measurement performance.

Challenges of inpatient blood glucose monitoring: standards, methods, and devices to measure blood glucose

Glucose control in the hospital setting is very important. There is a high incidence of hyperglycemia, hypoglycemia, and glycemic variability in hospitalized patients. Safe insulin delivery and glucose control is dependent on reliable glucose meters and monitoring systems in the hospital. Different glucose monitoring systems use arterial, venous, central venous, and capillary blood samples. It is important for clinicians to be aware that there are limitations of specific point-of-care (POC) glucose meters and that situations exist whereby POC glucose meters as the sole measurement device should be avoided. POC meter devices are not approved by the Food and Drug Administration for use in critical care, although POC meter devices are commonly used in critical care settings and elsewhere. This review focuses on glucose assay principles, instrument technology, influences on glucose measurement, standards for glucose measurement, and an evaluation of different methods to measure blood glucose in the hospital setting.

Results of a survey among GP practices on how they manage patient safety aspects related to point-of-care testing in every day practice

Background

Point-of-care (POC) tests are devices or test strips that can be used near or at the site where care is delivered to patients, enabling a relatively fast diagnosis. Although many general practitioners (GPs) in the Netherlands are using POC tests in their practice, little is known on how they manage the corresponding patient safety aspects.

Methods

To obtain information on this aspect, an invitation to participate in a web-based questionnaire was sent to a random sample of 750 GP practices. Of this sample 111 GP practices returned a complete questionnaire. Data was analysed by using descriptive statistics.

Results

Results show that there is not always attention for quality control measures such as checking storage conditions, executing calibration, and maintenance. In addition, universal hygienic measures, such as washing hands before taking a blood sample, are not always followed. Refresher courses on the use of POC tests are hardly organized. Only a few of the GPs contact the manufacturer of the device when a device failure occurs. Well-controlled aspects include patient identification and actions taken when ambiguous test results are obtained.

Conclusions

We observed a number of risks for errors with POC tests in GP practices that may be reduced by proper training of personnel, introduction of standard operating procedures and measures for quality control and improved hygiene. To encourage proper use of POCT in general practices, a national POCT guideline, dedicated to primary care and in line with ISO standards, should be introduced.

Electronic supplementary material

The online version of this article (doi:10.1186/s12875-014-0217-2) contains supplementary material, which is available to authorized users.

Point-of-care blood glucose testing for diabetes care in hospitalized patients: an evidence-based review

Glycemic control in hospitalized patients with diabetes requires accurate near-patient glucose monitoring systems. In the past decade, point-of-care blood glucose monitoring devices have become the mainstay of near-patient glucose monitoring in hospitals across the world. In this article, we focus on its history, accuracy, clinical use, and cost-effectiveness. Point-of-care devices have evolved from 1.2 kg instruments with no informatics to handheld lightweight portable devices with advanced connectivity features. Their accuracy however remains a subject of debate, and new standards for their approval have now been issued by both the International Organization for Standardization and the Clinical and Laboratory Standards Institute. While their cost-effectiveness remains to be proved, their clinical value for managing inpatients with diabetes remains unchallenged. This evidence-based review provides an overall view of its use in the hospital setting.

Performance of community blood glucose meters in calgary, alberta: an analysis of quality assurance data

OBJECTIVE

The self-monitoring of blood glucose plays a critical role in management of diabetes mellitus. Although laboratory comparisons of glucose meter accuracy are often acceptable, clinical comparisons show frequent inaccuracies. In this paper, we evaluate the accuracy of self-monitoring blood glucose meters using glucose meter and serum comparisons from a large Canadian laboratory.

METHODS

This study was performed using secondary data obtained from the Laboratory Information System of Calgary Services, the sole provider of laboratory testing to Calgary and surrounding areas. We examined anonymous quality assurance data for glucose meter comparisons performed on home glucose meters between January 1, 2010, and April 30, 2013.

RESULTS

A total of 39 542 comparisons were recorded on 18 540 different subjects. Overall, 6.7% of differences were greater than the current International Standards Organization standard of 15%, and 3.7% exceeded the Canadian guideline of 20%.

CONCLUSIONS

Glucose meter checks were infrequently performed (on average, once per 1.6 years). A significant subset of meter results was inaccurate.

Glucose control in non-critically ill inpatients with diabetes: towards closed-loop

Inpatient glycaemic control remains an important issue due to the increasing number of patients with diabetes admitted to hospital. Morbidity and mortality in hospital are associated with poor glucose control, and cost of hospitalization is higher compared to non-diabetes patients. Guidelines for inpatient glycaemic control in the non-critical care setting have been published. Current recommendations include basal-bolus insulin therapy, regular glucose monitoring, as well as enhancing healthcare provider's role and knowledge. In spite of growing focus, implementation in practice is limited, mainly due to increasing workload burden on staff and fear of hypoglycaemia. Advances in healthcare technology may contribute to an improvement of inpatient diabetes care. Integration of glucose measurements with healthcare records and computerized glycaemic control protocols are currently being used in some institutions. Recent interests in continuous glucose monitoring have led to studies assessing its utilization in inpatients. Automation of glucose monitoring and insulin delivery may provide a safe and efficacious tool for hospital staff to manage inpatient hyperglycaemia, whilst reducing staff workload. This review summarizes the evidence on current approaches to managing inpatient glycaemic control; its utility and limitations. We conclude by discussing the evidence from feasibility studies to date, on the potential use of closed loop in the non-critical care setting and its implication for future studies.

Use of portable blood physiology point-of-care devices for basic and applied research on vertebrates: a review

Non-human vertebrate blood is commonly collected and assayed for a variety of applications, including veterinary diagnostics and physiological research. Small, often non-lethal samples enable the assessment and monitoring of the physiological state and health of the individual. Traditionally, studies that rely on blood physiology have focused on captive animals or, in studies conducted in remote settings, have required the preservation and transport of samples for later analysis. In either situation, large, laboratory-bound equipment and traditional assays and analytical protocols are required. The use of point-of-care (POC) devices to measure various secondary blood physiological parameters, such as metabolites, blood gases and ions, has become increasingly popular recently, due to immediate results and their portability, which allows the freedom to study organisms in the wild. Here, we review the current uses of POC devices and their applicability to basic and applied studies on a variety of non-domesticated species. We located 79 individual studies that focused on non-domesticated vertebrates, including validation and application of POC tools. Studies focused on a wide spectrum of taxa, including mammals, birds and herptiles, although the majority of studies focused on fish, and typical variables measured included blood glucose, lactate and pH. We found that calibrations for species-specific blood physiology values are necessary, because ranges can vary within and among taxa and are sometimes outside the measurable range of the devices. In addition, although POC devices are portable and robust, most require durable cases, they are seldom waterproof/water-resistant, and factors such as humidity and temperature can affect the performance of the device. Overall, most studies concluded that POC devices are suitable alternatives to traditional laboratory devices and eliminate the need for transport of samples; however, there is a need for greater emphasis on rigorous calibration and validation of these units and appreciation of their limitations.

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.