Point-of-care Laboratory Research Articles

Evaluation of the analytical and clinical performance of a high-sensitivity troponin I point-of-care assay in the Mersey Acute Coronary Syndrome Rule Out Study (MACROS-2).

The objective of this study is to evaluate the analytical and diagnostic performance of a high-sensitivity point-of-care (POC) cardiac troponin I assay, the Quidel TriageTrue™ (QuidelOrtho Inc, San Diego, USA), compared to central laboratory testing (CLT) in accelerated diagnostic protocols (ADP) in real time in a clinical environment. In a nested sub-study of a pragmatic randomised control trial, consecutive patients with suspected acute coronary syndrome (ACS) and chest pain <12 h duration were randomised to the ESC 0/1 and 0/3-h ADP. Subjects underwent sampling for Quidel TriageTrue POC hs-TnI whole blood and plasma, CLT hs-TnT Roche Elecsys and a validated, NICE approved CLT High sensitivity cardiac troponin I (hs-TnI) (Siemens Attellica) at each time point. Assay imprecision was assessed by repeat analysis of whole blood samples at three levels (low, near 10 % CV 5-10 ng/L, medium, approximating 99th percentile 15-25 ng/L and high, 3-5 times the 99th percentile, 60-100 ng/L). Final diagnosis was adjudicated at 6weeks by Roche hs-TnT using the 4th universal definition of myocardial infarction (MI). A total of 1,157 patients consented and had both investigational POC whole blood and plasma and central lab hs-cTn available. The median age was 59, 47.2 % were female and 15 % had suffered a previous MI. Assay imprecision of whole blood POC TriageTrue revealed 10 % CV at 8.6 ng/L (>50 % lower than 99th percentile [20.5 ng/L]) and a 20 % CV at 1.2 ng/L. Receiver operator characteristics (ROC) curves were computed for each assay against adjudicated index type 1 MI to study clinical performance. At all-time points there were excellent performance for whole blood POC TriageTrue: area under the curve (AUC) 0.97 [95 % CI 0.94-098], 0.98 [95 % CI 0.97-1.00] and 0.95 [95 % CI 0.92-0.98] at time 0, 1 and 3 h respectively. There was statistical equivalence for performance of whole blood and plasma POC TriageTrue hs-TnI and laboratory Siemens Atellica hs-TnI. The whole blood POC TriageTrue hs-TnI assay demonstrates imprecision levels consistent with high sensitivity characteristics and has a clinical performance equivalent to an established, validated and NICE approved laboratory Siemens Atellica hs-TnI.

Correlation between the prothrombin time values obtained by point-of care prothrombin time meter and clinical laboratory in paediatric intensive care unit of a developing country

Background: Monitoring of prothrombin time (PT) is essential for adequate management of children in pediatric intensive care unit (PICU) who require serial and repeated PT measurements. In contrast to laboratory testing, point-of-care (POC) PT meters have been configured especially for bedside that are cost effective with rapid turnaround time. Our study aimed to assess its feasibility for routine use in PICU by assessing the correlation between PT values obtained through the POC PT meter and those acquired from the laboratory. Methods: A total of 200 children of either gender aged between 1 month to 12 years, admitted to PICU of Indus hospital Karachi Pakistan from February to August 2023 were analysed in this cross-sectional study. Venous blood samples were collected in PT bottles and transported to the pathology department within a time frame of 20-30 minutes for analysis. Concurrently, a drop of blood was obtained via finger prick and promptly assessed using the POC device-Coaguchek INRange system, (Roche diagnostics Ltd, USA). Pearson’s correlation was applied. Results: 200 children (96 males, 104 females) having a mean age of 6.42±3.55 years. The mean PT values with POC meter and Laboratory were 2.588±1.299 and 2.574±1.304 respectively (p=0.100). Very strong correlation of PT between POC PT meter and laboratory evaluation was observed (r=0.996, p&lt;0.001). Conclusions: The strong correlation observed between POC PT meter and laboratory supports the use of these devices for timely coagulation monitoring, potentially improving patient outcomes in PICUs.

Application and comparison of point-of-care devices for field evaluation of underlying health status of Guatemalan sugarcane workers.

With chronic disease prevalence on the rise globally, surveillance and monitoring are critical to improving health outcomes. Point-of-care (POC) testing can facilitate epidemiological research and enhance surveillance systems in limited resource settings, but previous research has identified bias between POC devices and laboratory testing. We compared the performance of two POC blood analyzers, the iSTAT handheld (Abbott, Princeton, NJ, USA) and the StatSensor Creatinine (Nova Biomedical, Waltham, MA, USA) to concurrent blood samples analyzed at a local laboratory that were collected from 89 agricultural workers in Guatemala. We measured creatinine and other measures of underlying health status with the POC and the lab blood samples. Pearson correlation coefficients, Bland-Altman plots, no intercept linear regression models and two-sample t-tests were used to evaluate the agreement between the POC and lab values collected across three study days and to assess differences by study day in a field setting. On average there was no observed difference between the iSTAT and lab creatinine measurements (p = 0.91), regardless of study day. Using lab creatinine as the gold standard, iSTAT creatinine results were more accurate compared to the Statsensor, which showed some bias, especially at higher values. The iSTAT had good agreement with the lab for sodium and blood urea nitrogen (BUN), but showed differences for potassium, anion gap, bicarbonate (TCO2), glucose, and hematocrit. In this tropical field setting, the research team devised a protocol to prevent the devices from overheating. In limited resource settings, POC devices carry advantages compared to traditional lab analyses, providing timely results to patients, researchers, and healthcare systems to better evaluate chronic health conditions. Technical challenges due to use of POC devices in high heat and humidity environments can be addressed using a standard protocol for transporting and operating the devices.

Analytical performance comparing siemens whole blood point of care Atellica VTLi to the central laboratory plasma Atellica IM high-sensitivity cardiac troponin I assays

IntroductionThis study examined the analytical performance of a whole blood (WB) point of care (POC) hs-cTnI assay compared to a plasma central laboratory hs-cTnI assay in patients presenting with ischemic symptoms to a US emergency department. MethodsFresh WB specimens collected at 0 and 2 h from 1089 consecutive patients (2152 total from 1076 matched specimens) were analyzed for hs-cTnI using WB on POC Siemens Atellica VTLi assay and plasma on central laboratory Siemens Atellica IM assay. Concordances were determined based on concentrations ranging from < limit of detection (LoD), LoD to overall and sex specific 99th percentiles from both the IFCC manufacturer package inserts and Universal Sample Bank (USB) data, and > 99th percentiles. Method comparisons were calculated using Passing Bablok regression and Bland Altmann plots, and linear regression determined by Pearson correlation coefficient. ResultsBaseline concentration comparisons showed: POC VTLi < LoD 4–5 %, ≥ LoD 95 %; Atellica IM < LoD 5–7 %, and ≥ LoD 94–95 %. From the 2152 paired 0 and 2-hour samples, based on 99th percentiles, overall concordance was 91–92 % (kappa 0.72–0.77) and discordance 8 %. Passing Bablok regression analysis using 1924 specimens between LoD to 500 ng/L showed: slopes 0.469–0.490; y-intercepts 1.753–2.028; r values 0.631–0.817. Pearson correlation coefficient showed moderate to strong correlation strength, even with up to 53 % cTnI concentrations variance (Passing Bablok slopes) vs 27.0–40.1 % (Bland-Altmann plots). ConclusionsUp to 95 % of measured samples were > LoD for both the POC (Atellica VTLi) and central laboratory (Atellica IM) hs-cTnI assays. Moderate to strong concordance and correlation were observed between assays, despite up to 53 % variances in cTnI concentration.

Real-time metagenomics-based diagnosis of community-acquired meningitis: A prospective series, southern France.

SummaryBackgroundPoint-Of-Care (POC) diagnosis of life-threatening community-acquired meningitis currently relies on multiplexed RT-PCR assays, that lack genotyping and antibiotic susceptibility profiling. We assessed the usefulness of real-time metagenomics (RTM) directly applied to the cerebrospinal fluid (CSF) for the identification, typing and susceptibility profiling of pathogens responsible for community-acquired meningitis.MethodsA series of 52 CSF samples from patients suspected of having community-acquired meningitis, were investigated at POC by direct RTM in parallel to routine real-time multiplex PCR (RT-PCR) and bacterial culture, for the detection of pathogens. RTM-generated sequences were blasted in real-time against an in-house database incorporating the panel of 12 most prevalent pathogens and against NCBI using EPI2ME online software, for pathogen identification. In-silico antibiogram and genotype prediction were determined using the ResFinder bio-tool and MLST online software.FindingsOver eight months, routine multiplex RT-PCR yielded 49/52 positive CSFs, including 21 Streptococcus pneumoniae, nine Neisseria meningitidis, eight Haemophilus influenzae, three Streptococcus agalactiae, three Herpesvirus-1, two Listeria monocytogenes, and one each of Escherichia coli, Staphylococcus aureus and Varicella-Zoster Virus. Parallel RTM agreed with the results of 47/52 CSFs and revealed two discordant multiplex RT-PCR false positives, one H. influenzae and one S. pneumoniae. Both multiplex RT-PCR and RTM agreed on the negativity of three CSFs. While multiplex RT-PCR routinely took 90 min, RTM took 120 min, although the pipeline analysis detected the pathogen genome after 20 min of sequencing in 33 CSF samples; and after two hours in 14 additional CSFs; yielding > 50% genome coverage in 19 CSFs. RTM identified 14 pathogen genotypes, including a majority of H. influenzae b, N. meningitidis B and S. pneumoniae 11A and 3A. In all 16 susceptible cultured bacteria, the in-silico antibiogram agreed with the in-vitro antibiogram in 10 cases, available within 48 h in routine bacteriology.InterpretationIn addition to pathogen detection, RTM applied to CSF samples offered supplementary information on bacterial profiling and genotyping. These data provide the proof-of-concept that RTM could be implemented in a POC laboratory for one-shot diagnostic and genomic surveillance of pathogens responsible for life-threatening meningitis.FundingThis work was supported by the French Government under the Investments in the Future programme managed by the National Agency for Research reference: Méditerranée Infection 10-IAHU-03.

Point-of-care high-sensitivity troponin-I analysis in capillary blood for acute coronary syndrome diagnostics.

Patients with acute coronary syndrome (ACS) should be referred promptly to the hospital to reduce mortality and morbidity. Differentiating between low-risk and high-risk patients remains a diagnostic challenge. Point-of-care testing can contribute to earlier disposition decisions for patients excluded from ACS. This study describes the validation of the Atellica® VTLi. Patient-side Immunoassay Analyzer for high-sensitivity troponin point-of-care (POC) analysis. (TheAtellica VTLi is not available for sale in the USA. The products/features (mentioned herein) are not commercially available in all countries. Their future availability cannot be guaranteed). A total of 152 patients with acute chest pain admitted at the cardiac emergency department (ED) were included in the study. Capillary blood was compared with a whole blood and plasma sample obtained by venipuncture. All samples were analyzed using the Atellica VTLi Patient-side Immunoassay Analyzer; in addition, plasma was analyzed by a central lab immunoassay analyzer. No significant difference was observed between venous whole blood vs. plasma analyzed by the Atellica VTLi Patient-side Immunoassay Analyzer. The difference between capillary blood and venous blood showed a constant bias of 7.1%, for which a correction factor has been implemented. No clinically relevant differences were observed for the capillary POC results compared to plasma analyzed with a standard immunoassay analyzer. The Atellica VTLi Patient-side Immunoassay Analyzer for high-sensitivity troponin analysis shows equivalent results for all sample types, including capillary blood. No clinically relevant discordances were observed between capillary POC and central laboratory results. With additional studies, this could pave the way towards rapid testing of high-sensitivity troponin in the ambulance or the general practitioner's office without the need for hospitalization of patients with acute chest pain.

Point-of-care versus central laboratory measurements of electrolytes and hemoglobin: A prospective observational study in critically ill patients in a tertiary care hospital.

A blood gas analyzer is a point-of-care (POC) testing device used in the Emergency Department (ED) to manage critically ill patients. However, there were differences in results found from blood gas analyzers for hemoglobin (Hgb) and electrolytes parameters. We conducted a comparative validity study in ED in patients who had requirements of venous gas analysis, complete blood count, and electrolytes. The objective was to find the correlation of Hgb, sodium (Na+), and potassium (K+) values between the blood gas analyzer and laboratory autoanalyzer. A total of 206 paired samples were tested for Hgb, Na+, and K+. Total 4.6 ml of venous blood was collected from each participant, 0.6 ml was used for blood gas analysis as POC testing and 4 ml was sent to the central laboratory for electrolyte and Hgb estimation. The mean difference between POC and laboratory method was 0.608 ± 1.41 (95% confidence interval [CI], 0.41-0.80; P < 0.001) for Hgb, 0.92 ± 3.5 (95% CI, 0.44-1.40) for Na+, and 0.238 ± 0.62 (95% CI, -0.32-0.15; P < 0.001) for K+. POC testing and laboratory method showed a strong positive correlation with Pearson correlation coefficient (r) of 0.873, 0.928, and 0.793 for Hgb, Na+, and K+, respectively (P < 0.001). Although there was a statistical difference found between the two methods, it was under the United States Clinical Laboratory Improvement Amendment range. Hence, starting the therapy according to the blood gas analyzer results may be beneficial to the patient and improve the outcome.

Comparison of point-of-care NOVA CCX blood gas analyzer to laboratory analyzer in a population of healthy adult cats.

To compare the level of agreement of measurement of analytes (sodium, chloride, potassium, urea nitrogen [UN], creatinine, glucose) in a population of healthy adult cats between the point-of-care (POC) analyzer and laboratory analyzer. To establish reference intervals for the POC analyzer in healthy adult cats. Prospective observational study. University teaching hospital. Fifty-five cats were screened. Seven cats were excluded due to aggression that prohibited phlebotomy, and 1 cat was excluded due to prolonged restraint; 47 cats were enrolled. None. In this patient population, reference intervals for the POC analyzer were calculated: sodium 145-157mmol/L; chloride 116-124mmol/L; potassium 3.4-5.5mmol/L; UN 5.71-13.9mmol/L (16-39mg/dl); creatinine 74.3-189.2mmol/L (0.84-2.14mg/dl); and glucose 4-11.8mmol/L (72-213mg/dl). Comparison between the POC analyzer and laboratory analyzer using the Bland-Altman method was performed. The bias for each analyte is as follows: sodium 1.55mmol/L; chloride 0.99mmol/L; potassium 0.21mmol/L; UN -0.25mmol/L (-0.7mg/dl); creatinine 9.73mmol/L (0.11mg/dl); and glucose 0.5mmol/L (9.79mg/dl). Reference intervals for each analyte were similar to other chemistry analyzers. There was no significant difference between the POC and laboratory analyzers in analysis of UN, with a statistically significant difference observed with sodium, potassium, chloride, creatinine, and glucose. However, the values are likely not sufficiently different to alter initial clinical decisions regarding patient care.

Evaluation of a continuous glucose monitoring system in neonatal foals.

BackgroundMonitoring blood glucose concentrations is common in critically ill neonatal foals, especially septic foals and those receiving naso‐esophageal feedings or IV parenteral nutrition. Glucose typically is measured using a point‐of‐care (POC) glucometer but requires repeated restraint and blood collections, which may cause irritation at venipuncture sites and increased demands on nursing staff. Continuous glucose monitoring systems (CGMS) may provide an accurate alternative for monitoring blood glucose concentration.ObjectivesTo determine the correlation and accuracy of a CGMS to monitor neonatal foals' blood glucose concentrations as compared to a POC glucometer and laboratory chemistry analysis (CHEM).AnimalsSamples from 4 healthy and 4 ill neonatal foals.MethodsA CGMS was placed on each foal, and glucose measurements acquired from this device were compared to simultaneous measurements of blood glucose concentration using a POC glucometer and CHEM.ResultsTwo‐hundred matched glucose measurements were collected from 8 neonatal foals. The mean bias (95% limits of agreement) between CGMS and CHEM, CGMS and POC glucometer, and POC glucometer and CHEM was 3.97 mg/dL (−32.5 to 40.4), 18.2 mg/dL (−28.8 to 65.2), and 22.18 mg/dL (−9.3 to 53.67), respectively. The Pearson's correlation coefficient (r) was significantly correlated among all devices: GCMS and CHEM (r = 0.81), CGMS and POC glucometer (r = 0.77) and POC glucometer‐CHEM (r = 0.92).Conclusions and Clinical ImportanceWithin the blood glucose concentration ranges in this study (78‐212 mg/dL), CGMS measurements were significantly correlated with CHEM, suggesting that it is an acceptable method to provide meaningful, immediate, and continuous glucose concentration measurements in neonatal foals while eliminating the need for repeated restraint and blood collection.

Diagnostic accuracy of semiquantitative point of care urine albumin to creatinine ratio and urine dipstick analysis in a primary care resource limited setting in South Africa

BackgroundThe prevalence of chronic kidney disease (CKD) is predicted to rise over the next few decades. In resource-limited settings access to central laboratory services is limited. Point-of-care (POC) urine dipstick testing offers the potential to detect markers of kidney damage (albuminuria) as well as markers of other disease processes. We evaluated the diagnostic accuracy of the semi-quantitative albumin-creatinine ratio (ACR) Sysmex UC-1000 POC urine dipstick system as well as the extent of other abnormal dipstick findings in urine.Methods700 participants from a rural area in South Africa were screened for albuminuria. A spot urine sample was used to measure POC and central laboratory ACR. We determined the sensitivity, specificity, positive predictive value and negative predictive value of the POC ACR, and recorded dipstick parameters.ResultsThe prevalence of albuminuria was 11.6% (95%CI; 9.3–14.2). Those with albuminuria had higher mean diastolic (82 vs 79 mmHg, p = 0.019) and systolic (133 vs 128 mmHg, p = 0.002) blood pressures and a higher proportion of diabetes mellitus (17.6 vs 4.9%, p < 0.001). The sensitivity of the POC ACR system was 0.79, specificity 0.84, positive predictive value 0.39 and negative predictive value 0.97. The sensitivity improved to 0.80, 0.85, 0.85 and 0.89 in those with elevated blood pressure, diabetes mellitus, HIV positive status, and those 65 years and older, respectively. Abnormalities other than albuminuria were detected in 240 (34.3%) of the samples; 88 (12.6%) were positive for haematuria, 113 (16.1%) for leucocytes, 66 (9.4%) for nitrites and 27 (3.9%) for glycosuria.ConclusionOur study shows that POC ACR has good negative predictive value and could be used to rule out albuminuria when screening for CKD. Additionally, a high proportion of participants had other urine abnormalities detected with dipsticks which may reflect kidney disease or co-morbid untreated genitourinary pathology such as urinary tract infections or endemic schistosomiasis with important implications for CKD.

Comparison of serum and plasma SDMA measured with point-of-care and reference laboratory analysers: implications for interpretation of SDMA in cats.

Symmetric dimethylarginine (SDMA) reflects the glomerular filtration rate (GFR) in people, dogs and cats. Initial assays used a liquid chromatography-mass spectroscopy (LC-MS) technique. A veterinary immunoassay has been developed for use in commercial laboratories and point-of-care (POC) laboratory equipment. This study sought to: determine POC and commercial laboratory (CL) SDMA assay imprecision; determine any bias of the POC assay compared with the CL assay; calculate observed total error of the POC assay and compare with analytical performance goals; and calculate dispersion and sigma metrics (σ) for POC and CL SDMA methods. Two separate studies were performed that assessed: (1) imprecision, determined by evaluation of pooled feline plasma or serum; and (2) bias, assessed by comparing pooled plasma and serum results, as well as paired analyses of clinical samples from a single venepuncture measured using both analysers. Results were assessed in relation to performance goals. Dispersion and σ were calculated for both analysers. Bias between CL and POC analysers was consistent and high numbers of clinical results were outside performance goals across both studies. Imprecision was poor for both analysers for study 1 and improved to within quality goals for the CL analyser for study 2. Dispersion was at least 40%, meaning a measured result of 14 μg/dl represents a range of possible results from 8 μg/dl to 20 μg/dl. Clinicians should be careful ascribing medical significance to small changes in SDMA concentration, as these may reflect analytical and biological variability. Analyser-specific reference intervals are likely required.

The Clinical Review Committee: Impact of the Development of In Vitro Diagnostic Tests for SARS-CoV-2 Within RADx Tech.

The NIH Rapid Acceleration of Diagnostics (RADxSM) Tech Program was created to speed the development, validation, and commercialization of innovative point-of-care (POC) and home-based tests, and to improve clinical laboratory tests, that can directly detect SARS-CoV-2. Leveraging the experience of the Point-of-Care Technologies Research Network, a Clinical Review Committee (CRC) composed of clinicians, bioengineers, regulatory experts, and laboratorians was created to provide structured feedback to SARS-CoV-2 diagnostic innovators. The CRC convened 53 meetings with 49 companies offering SARS-CoV-2 tests in POC and reference laboratory formats as well as collection materials. The CRC identified common barriers to device design finalization including biosafety, workflow, result reporting, regulatory requirements, sample type, supply chain, limit of detection, lack of relevant validation data, and price-performance-use mismatch. Feedback from companies participating was positive.

Point-of-Care Laboratory Data Collection During Critical Care Transport

ObjectiveCritical care transport involves a high level of intensive clinical care in a resource-limited environment. These patients require multiple assessments guiding specialty treatments, including blood product administration, intravenous electrolyte replacement, ventilator management, and extracorporeal membrane oxygenation. This study aims to measure the usage of point-of-care (POC) laboratory data during critical care transport. MethodsData were collected via electronic medical record review over 1 year of use in a hospital-based critical care rotor wing, fixed wing, and ground critical care transport team in the Southeastern United States. ResultsOne hundred twenty POC tests were performed during 1,075 critical care transports over the 1-year period (8.9%). Patient transportations involved 35 extracorporeal membrane oxygenation, 21 medical, 17 cardiac, 13 neonatal, 11 respiratory failure, 8 gastrointestinal bleeding, 6 neurologic, 5 pediatrics, 3 trauma, and 1 organ donor. Seventy-eight POC laboratory tests (65%) required intervention, including ventilator changes (39.7%), electrolyte replacement (35.8%), blood products (7.6%), and other (12.8%). The remaining 42 (35%) POC laboratory tests confirmed no intervention was necessary (n = 35) and that ongoing treatments were effective (n = 7). ConclusionPOC laboratory testing performed during critical care transport guides providers in performing essential emergent interventions in a timelier manner that may benefit critically ill patients.

Detection of Falsely Elevated Point-of-Care Potassium Results Due to Hemolysis Using Predictive Analytics.

Preanalytical factors, such as hemolysis, affect many components of a test panel. Machine learning can be used to recognize these patterns, alerting clinicians and laboratories to potentially erroneous results. In particular, machine learning might identify which cases of elevated potassium from a point-of-care (POC) basic metabolic panel are likely erroneous. Plasma potassium concentrations were compared between POC and core laboratory basic metabolic panels to identify falsely elevated POC results. A logistic regression model was created using these labels and the other analytes on the POC panel. This model has high predictive power in classifying POC potassium as falsely elevated or not (area under the curve of 0.995 when applied to the test data set). A rule-in and rule-out approach further improves the model's applicability with a positive predictive value of around 90% and a negative predictive value near 100%. Machine learning has the potential to detect laboratory errors based on the recognition of patterns in commonly requested multianalyte panels. This could be used to alert providers at the POC that a result is suspicious or used to monitor the quality of POC results.

Point-of-Care Hemoglobin A1C Testing System in Community Settings: Challenges, Opportunities, and Measurement Characteristics.

Point-of-care (POC) hemoglobin A1c (A1C) testing provides clinicians and diabetic patients real-time information on glycemic control. POC testing in community settings may expand reach, but feasibility is underexplored. We sought to describe challenges, opportunities, and quality control results of POC testing conducted in community food pantries. Food bank staff who were directly involved in POC testing provided feedback in telephone interviews, weekly team calls, and quarterly open-ended surveys. We evaluated device performance using test-retest comparisons (n = 58) and comparisons between POC results and laboratory results from medical records (n = 72). Study staff performed 1,771 POC A1c tests. Barriers were administrative, regulatory, and operational. Opportunities included ease of training and high participant satisfaction. There was high test-retest correlation (r = 0.97) and high correlation between POC results and laboratory results from medical records (r = 0.85). Community POC testing programs are feasible and relatively accurate, but implementation requires resources and capacity building. This trial is registered at www.clinicaltrials.gov with identifier NCT02569060, registered October 6, 2015, https://clinicaltrials.gov/ct2/show/NCT02569060.

The impact of intensified clinical care on glycaemic control in patients with type 2 diabetes at Khayelitsha Community Health Centre, South Africa: Quasi-experimental study

AimThe aim was to evaluate the effect on glycaemic control of more intensive care for patients with very uncontrolled type-2 diabetes (HbA1c>10%) at Khayelitsha Community Health Centre, South Africa. MethodsA pragmatic, quasi-experimental study. Patients with HBA1c>10% were consecutively selected into a 6-month programme of intensified care involving monthly visits to a doctor, diabetes group education, escalation of treatment, and more frequent HbA1c testing by either point-of-care (POC) or laboratory. Participants were their own controls in a retrospective analysis of usual care during the previous year. ResultsAt baseline 236 patients had a mean HbA1c of 12.1%. The mean difference in HbA1c in the intervention group was −1.1% (p<0.001). The intervention group were exposed to group diabetes education (100% vs 0%), more visits (3.8 vs 3.2, p<0.001), more HbA1c tests (2.2 vs 0.9, p<0.001). There was no difference in increased dose of insulin between the groups or between POC and standard laboratory intervention sub-groups. ConclusionThe introduction of group diabetes education was the most likely explanation for improved glycaemic control in this poor, under-resourced, public sector, peri-urban setting. The study demonstrates a feasible approach to improving diabetes care in the South African context.

Accuracy of Point-of-Care Blood Glucose Level Measurements in Critically Ill Patients with Sepsis Receiving High-Dose Intravenous Vitamin C.

High-dose intravenous vitamin C is a potential treatment option for patients with sepsis and may interfere with point-of-care (POC) blood glucose (BG) testing. This study aimed to determine if vitamin C dosing used for sepsis affected POC BG level results. Prospective observational pilot study. Intensive care unit in a large academic tertiary care medical center. Five consecutive critically ill adults hospitalized between April 1 and June 1, 2017, who received two or more doses of intravenous vitamin C 1500 mg for the treatment of sepsis and had at least two paired POC BG levels and laboratory venous BG levels measured within 1 hour of each other during vitamin C therapy. The performance of POC BG level measurement was compared with the reference method of laboratory BG level measurement. The concordance to minimum accuracy criteria for BG meters set forth by the International Organization for Standardization (ISO) 15197:2013, the measurement of agreement between POC BG level and laboratory BG level using the Bland-Altman method, and the clinical accuracy through Parkes error grid analysis were assessed. A total of 16 paired POC and laboratory BG level measurements from the five patients were included. The accuracy of POC BG with laboratory BG level measurements during vitamin C administration according to ISO 15197:2013 criteria was 81.3%, which did not meet the minimum accuracy criteria of 95%. The Bland-Altman analysis showed a mean difference between POC and laboratory BG levels of 8.9 mg/dl, and the Parkes error grid analysis showed that the differences between POC and laboratory BG level measurements would not have resulted in a change in clinical action. The accuracy and agreement of POC and laboratory BG level measurements in critically ill patients receiving vitamin C were consistent with previously published reports in critically ill patients not receiving vitamin C and did not demonstrate clinically significant interference due to vitamin C dosing for sepsis.

Benefits and Pitfalls of Point-of-Care Coagulation Testing for Anticoagulation Management

Point-of-care (POC) testing is generally less precise and has higher reagent costs per test than laboratory-based assays. However, POC hemostasis testing can offer significant advantages in particular situations: patient-managed warfarin therapy as well as rapid turnaround time heparin management for intraoperative patients. Of note, POC hemostasis testing is generally approved for the purposes of anticoagulation monitoring and is inferior to laboratory coagulation testing for the diagnosis of congenital or acquired coagulopathy. The frequently used POC coagulation instruments for POC international normalized ratio and activated clotting time are reviewed, as well as their typical performance relative to central laboratory testing (where available). Several cases are discussed that highlight the benefits, as well as pitfalls, of POC coagulation testing. POC coagulation testing for anticoagulation monitoring offers advantages in particular situations. Clear policies and protocols must be developed to guide proper use of POC versus central laboratory hemostasis testing.

P105: Transforming emergency stroke care through innovation: Canadas first stroke ambulance

Introduction: A two-year Stroke Ambulance (SA) pilot project was implemented at the University of Alberta Hospital (UAH) in February, 2017, the first in the world to utilize this specialized technology in a rural setting. The primary objective is to evaluate clinical and economic implications of timely SA assessment and treatment of hyperacute stroke patients who present to non-stroke centres in rural Alberta and might otherwise have received delayed treatment, or not at all, due to prolonged transfer times. Methods: A steering committee and seven working groups were established, with representation from Alberta Health Services (AHS) programs impacted, to ensure comprehensive project development and implementation. The SA portable CT scanner, point of care laboratory, and videoconference system facilitate diagnosis of stroke in the field. The multidisciplinary team includes a stroke fellow, advanced &amp; primary care paramedics, registered nurse, CT technologist, and telestroke physician. When not dispatched, the team provides stroke expertise and patient care in the emergency department (ED) and diagnostic imaging. The service model includes suspected stroke patients presenting to non-stroke centres within a 250 Km radius of Edmonton (Phase I); patients presenting to Edmonton Zone (EZ) hospitals without CT capability and/or tPA protocols (Phase 2); and expedited transport from EZ hospitals to the UAH for urgent endovascular therapy (EVT) (Phase 3). A health economic analysis will compare stroke ambulance care with standard care. Results: The SA has responded to 54 dispatches, 13 patients thrombolyzed and 3 patients receiving EVT. Median rendezvous to CT time was 10 minutes, median rendezvous to tPA time was 21 minutes, and mean time from symptom onset to tPA was 180 minutes. There were no complications. After SA imaging and assessment, 18 patients were repatriated back to their local community hospital, avoiding unnecessary admission to tertiary care. Conclusion: Our preliminary experience demonstrates that the SA offers a novel approach to performing timely evaluation and treatment of suspected stroke from non-stroke centres and may serve as an excellent triage mechanism, reducing avoidable admissions to overcapacity tertiary care EDs. The SA team provides added value to the ED with stroke expertise and patient care. A comprehensive health economic analysis will determine cost-effectiveness and whether spread is feasible.

Reliability of Point-of-Care Hematocrit Measurement During Liver Transplantation.

Although point-of-care (POC) analyzers are commonly used during liver transplantation (LT), the accuracy of hematocrit measurement using a POC analyzer has not been evaluated. In this retrospective observational study, we aimed to evaluate the accuracy of hematocrit measurement using a POC analyzer and identify potential contributors to the measurement error and their influence on mistransfusion during LT. We retrospectively collected 6461 pairs of simultaneous intraoperative hematocrit measurements using POC analyzers and laboratory devices during LTs in 901 patients. The agreement of hematocrit measurements was assessed using Bland-Altman analysis for repeated measurements, while the incidence and magnitude of hematocrit measurement error were compared among 16 different laboratory abnormality categories. A generalized estimating equation analysis was performed to identify potential contributors to falsely low-measured POC hematocrit. Additionally, we defined potential "overtransfusion" in the case when POC hematocrit was <20% and laboratory hematocrit was ≥20% and investigated its association with intraoperative transfusion. The POC hematocrit measurements were falsely lower than the laboratory hematocrit measurements in 70.3% (4541/6461) of pairs. The median (interquartile range) of hematocrit measurement error was -1.20 (-2.60 to 0.20). Bland-Altman analysis showed that 24.5% (1583/6461) of the errors were outside our a priori defined clinically acceptable limits of ±3%. The incidence of falsely low-measured hematocrit was significantly higher with the presence of concomitant hypoalbuminemia and hypoproteinemia. Hypoalbuminemia combined with hyperglycemia showed significantly larger hematocrit measurement error. Hypoalbuminemia, hypoproteinemia, and hyperglycemia were predictors of falsely low-measured hematocrit. Furthermore, the overtransfusion group showed larger amount of transfusion than the adequately transfused group, with a median difference of 2 units (95% confidence interval [0-4], P = .039), despite similar amount of blood loss. Hematocrit measured using the POC device tends to be lower than the laboratory hematocrit measured during LT. Commonly encountered laboratory abnormalities during LT include hypoalbuminemia, hypoproteinemia, and hyperglycemia, which may contribute to falsely low-measured POC hematocrit. Careful consideration of these confounders may help reduce overtransfusion that occurs due to falsely low-measured POC hematocrit.