Evaluation of the i-STAT Point-of-Care Analyser

BACKGROUND: Point-of-care testing (POCT) is designed to be used near the site where the clinical care is being delivered. The demand for POCT in the medical field is expanding significantly, given that rapid results can eventually lead to early diagnosis and immediate clinical management of diseases. Therefore, the aim of this study was to evaluate the performance of the i-STAT POC analyser (Abbott Diagnostics, USA) for testing 8 chemical analytes (viz., sodium, potassium, chloride, total carbon dioxide, blood urea nitrogen, creatinine, glucose, and ionised calcium) and 2 hematological analytes (hematocrit [HCT], hemoglobin [Hb]). METHODS: The precision and linearity of the 10 analytes were measured according to Clinical and Laboratory Standards Institute (CLSI) EP15-A3 and EP6-A guidelines. Comparisons with a central laboratory hematology analyser, Coulter LH 780 (Beckman Coulter Inc., USA), and a chemical analyser, UniCel DxC 880i (Beckman Coulter Inc.), were performed using 85 patient samples according to CLSI EP9-A3. RESULTS: The coefficient of variation values for the within-run precision and total precision at 3 levels of all analytes were within 5%, except those for low level creatinine. In the aspect of linearity, the correlation coefficient values of all analytes were over 0.975 in the clinically important concentration range. A very high correlation was observed in glucose, blood urea nitrogen and creatinine (R>0.975), high correlation was observed in sodium, potassium, Hct and Hb (R>0.9), and relatively good correlation was observed in chloride and total carbon dioxide (R>0.7) compared to the central laboratory analysers. CONCLUSIONS: i-STAT showed relatively high precision and linearity, and comparable data to that of routine hematology and chemistry analysers. This device was concluded to have potential for providing faster results and relatively acceptable values to clinicians in need of immediate results.

Valores de referencia de gases arteriales y de electrolitos en caninos de la sabana de Bogotá / Reference Values of Arterial Gases and Electrolytes in Canines from the Bogotá Savanna / Valores de referência de gases arteriais e de eletrólitos em caninos da savana de Bogotá

Debido a la ausencia de valores de gasometría arterial que se ajusten a nuestras condiciones ambientales y a la amplia variedad de datos no actualizados en la literatura y utilizados en la práctica diaria, obtenidos con alturas, razas y equipos diferentes a los disponibles en nuestro medio, es necesario generar conocimiento propio ajustado a nuestra realidad. Se realizó una medición sistemática al azar de sangre arterial y venosa en 100 caninos sanos a la altura de la sabana de Bogotá (Chía: 2652 msnm; Cajicá: 2558 msnm; Sopó: 2650 msnm; La Calera: 2718 msnm y Bogotá: 2630 msnm), utilizando el analizador I-STAT® con cartucho EG7+. Se encontraron valores de referencia de gasometría, electrolitos, bases efectivas y pH. Los valores fueron comparados entre cuatro grupos por peso. Para cada parámetro se realizó estadística descriptiva basada en promedio, desviación estándar, error estándar, y se hallaron los límites de confianza (95%) y los intervalos con desviación estándar (una y dos desviaciones). Se evidenció disminución de PCO2, PO2, SO2, bicarbonato, BE. El pH se encontró levemente aumentado, similar a lo reportado por autores a grandes alturas y diferentes (no corroborado estadísticamente) a reportes en literatura, en los que la altura no fue una variable. Aun así son usados frecuentemente como referencia en la práctica de pequeños animales; solo la presentó diferencias estadísticas por grupos de peso. Como conclusión, se evidenció una regulación del pH sanguíneo eficaz a 2600 msnm, con diferentes valores de bicarbonato, PCO2, PO2, BE, que indican la necesidad de obtener y utilizar valores de referencia acordes con condiciones locales.

Due to the lack of arterial gas values that meet our environmental conditions and the wide variety of out-of-date data in literature and used in everyday practice, obtained with different heights, breeds and equipment to the ones available in our context, it becomes necessary to generate our own knowledge adjusted to our reality. A random systematic measurement of arterial and venous blood was made on 100 healthy canines in the Bogotá Savanna (Chia: 2652 m.a.s.l.; Cajica: 2558 m.a.s.l.; Sopo: 2650 m.a.s.l.; La Calera: 2718 m.a.s.l.; and Bogotá: 2630 m.a.s.l.;), using the I-STAT® analyzer with EG7+ cartridge. Reference values were found for gasometry, electrolytes, effective basis and pH. The values were compared between four groups by weight. Descriptive statistics were made for each parameter based on average, standard deviation and standard error, and the trust limits (95%) and the intervals with standard deviation (one and two deviations) were found. A decrease on PCO2, PO2, SO2, bicarbonate and BE was evident. The pH was found to be slightly increased, similar to the one reported by authors at great heights and different (not statistically confirmed) from reports in literature, where height was not a variable. Even so, they are frequently used as reference in the practice of small animals; only PO2 presented statistical differences by groups of weight. As a conclusion, effective regulation of blood pH was evident at 2600 m.a.s.l., with different bicarbonate values, PCO2, PO2, BE, which suggest the need to obtain and use reference values consistent with local conditions.

Devido à ausência de valores de gasometria arterial que se ajuste a nossas condições ambientais e à ampla variedade de dados não atualizados na literatura e utilizados na prática diária, obtidos com alturas, raças e equipes diferentes aos disponíveis em nosso meio, é necessário gerar conhecimento próprio ajustado a nossa realidade. Realizou-se uma medição sistemática ao azar de sangue arterial e venoso em 100 caninos sãos à altura da savana de Bogotá (Chia: 2652 msnm; Cajicá: 2558 msnm; Sopó: 2650 msnm; a Calera: 2718 msnm e Bogotá: 2630 msnm), utilizando o analisador I-STAT® com cartucho EG7+. Encontraram-se valores de referência de gasometria, eletrólitos, bases efetivas e pH. Os valores foram comparados entre quatro grupos por peso. Para cada parâmetro se realizou estatística descritiva baseada na média, no padrão de desvio, erro padrão, e se encontrou os limites de confiança (95%) e os intervalos com desvio padrão (um e dois desvios). Evidenciou-se diminuição de PCO2, PO2, SO2, bicarbonato, BE. O pH se encontrou levemente aumentado, similar ao reportado por autores a grandes alturas e diferentes (não corroborado estatisticamente) a relatórios em literatura, onde que a altura não foi uma variável.. Ainda assim são usados frequentemente como referência na prática de pequenos animais; só a PO2 apresentou diferenças estatísticas por grupos de peso. Como conclusão, se evidenciou uma regulação do pH sanguíneo eficaz a 2600 msnm, com diferentes valores de bicarbonato, PCO2, PO2, BE, que indicam a necessidade de obter e utilizar valores de referência acordes com condições locais.

Clinical Evaluation of i-STAT in the Neonatal Intensive Care Unit / 대한진단검사의학회지

BACKGROUND: i-STAT (i-STAT Corporation, Princeton NJ, USA), a hand-held point-of-care testing (POCT) analyzer with rapidity and minimal sample requirement, has the potential to bring about a significant impact on the management of neonates. However, there should be an overall deliberation of the routine use of i-STAT in the neonatal intensive care unit (NICU) as to whether it is technically reliable and cost-effective. The aim of this study was to assess the clinical aspects of the implementation of i-STAT in the NICU. METHODS: We surveyed physicians and nurses to measure the present status of POCT. We ana-lyzed 84 tests performed in the central laboratory, 88 tests by blood gas analyzer in NICU, and 95 tests by i-STAT for NICU patients. We investigated the indications, turnaround time (TAT), cycle time, and impact on patient care in each case during both pre- and post-i-STAT periods. Costs and user acceptability were also examined. RESULTS: Survey responders wanted rapid results but did not accept the responsibility for the quality of POCT. Turnaround time of i-STAT was shorter than that of the central laboratory, but did not make an impact on cycle time. The cost of i-STAT is 2.2 times higher than central laboratory cost, but the users were satisfied with i-STAT mainly because of its small sample volume and speed. Central laboratory testing volume decreased by 14.3% after the introduction of i-STAT. CONCLUSIONS: i-STAT may be acceptable in the NICU setting. However, the behavioral patterns of physicians need to be changed and a selective use of i-STAT is warranted to maximize its cost-effectiveness. Future studies on the clinical outcome are required to substantiate the potential role of i-STAT.

Evaluation of the i-STAT Point-of-Care Testing Analyzer / 대한진단검사의학회지

BACKGROUND: The usages for the i-STAT point-of-care testing (POCT) analyzer are increasing in emergency departments, intensive care units and dialysis units. We evaluated the performance of the i-STAT as a POCT analyzer. METHODS: We evaluated the analytical performance of the i-STAT through the measurement of sodi-um (Na), potassium (K), hematocrit, ionized calcium (iCa), PO 2 , PCO 2 and pH. We used two disposable cartridges including EG6+ cartridge for Na, K, hematocrit, PO 2 , PCO 2 and pH and EG7+ for iCa. RESULTS: The i-STAT revealed good linearity in Na and K except in hematocrit (r2 =0.9973, 0.9988 and 0.9179, respectively). In the precision study, the within-run and total-run coefficients of variation (CV, %) were within 10%. A high correlation was found between the i-STAT POCT analyzer and the analyzers in the central laboratory except sodium. In the study of the operator's effect, the intrapersonal CV and interpersonal CV were within 10% except in the PO 2 analysis. CONCLUSIONS: With its rapid turnaround time, small sample requirement, ease of operation, the i-STAT seems appropriate for clinical use in the management of patients in the emergency department, intensive care units and dialysis units where immediate access to clinically relevant laboratory testing is required.

Evaluation of i-STAT(TM) Portable Clinical Analyzer in a Neonatal Intensive Care Units / 대한주산의학회잡지

OBJECTIVES: OCT(Point-of-Care Test), often translated as "Bedside laboratory", is a testing method used in most developed countries to conduct medical research. It is known to extract rapid results that can be applied in the intensive care unit. This study was conducted to investigate the correlation of the i-STAT(TM) POCT analyzer with the traditional test in the neonatal intensive care units. METHODS: 60 babies(birth weight > or =1.0kg) who were admitted to neonatal intensive care unit from June, 2000 to June, 2001 at Asan Medical Center requiring blood samples for the testing of arterial blood gas analysis(ABGA), electrolytes, hemoglobin(Hb), hematocrit(Hct), were included in the study. Blood samples were taken simultaneously to be tested by the traditional laboratory method and by i-STAT(TM) (i-STAT Co. USA) POCT analyzer. The data used for comparison analyzation included pH, pCO2, pO2, HCO3, Na, K, Hb, and Hct. RESULTS: 245 measurements of ABGA and 195 measurements of Na, K, Hb, Hct from 60 babies were used for comparison. Good correlation of data was found between i-STAT(TM) POCT analyzer and traditional laboratory method obtained from the central laboratory(correlation coefficient: pH 0.954, pCO2 0.944, pO2 0.941, HCO3 0.880, Na 0.713, K 0.860, Hb 0.864, Hct 0.880). CONCLUSION: This study showed that i-STAT(TM) POCT analyzer provided accurate analytic results when compared with traditional laboratory method used in the neonatal intensive care units.

Comparison of Conventional Chiron 348 pH/blood Gas/electrolytes Analyzer and i-STAT Portable Clinical Analyzer / 대한구급학회지

BACKGROUND: The development of so-called "Point-of-care" (POC) devices for blood or urine analysis has resulted in many systems that are widely used at home or at the bedside. We evaluated the performance of the I-STAT portable clinical analyzer for measuring blood gases (pH, PCO2, PO2) and whole blood electrolytes (sodium, potassium and ionized calcium) with reference to a conventional blood gas analyzer (Chiron 348 pH/ blood gas/electrolytes). METHODS: Thirty samples from the arterial blood were simultaneously analyzed with I-STAT system and with Chiron 348 pH/blood gas/ electrolytes analyzer. Differences between results of two methods were analyzed by paired t-test (p<0.05). RESULTS: PO2, PCO2 and Na measured with I-STAT system and Chiron 348 PH/ blood gas/ electrolytes analyzer showed no significant differences. pH, calculated HCO3, K and Ca measured by two methods showed significant difference, but observed differences would not affect clinical decisions except ionized calcium. CONCLUSIONS: This study shows that blood gas and electrolyte analysis using the I-STAT portable device is comparable with that performed by a conventional Chiron 348 pH/blood gas/ electrolytes analyzer except ionized calcium.