A wearable six-minute walk-based system to predict postoperative pulmonary complications after cardiac valve surgery: an exploratory study / 生物医学工程学杂志

In recent years, wearable devices have seen a booming development, and the integration of wearable devices with clinical settings is an important direction in the development of wearable devices. The purpose of this study is to establish a prediction model for postoperative pulmonary complications (PPCs) by continuously monitoring respiratory physiological parameters of cardiac valve surgery patients during the preoperative 6-Minute Walk Test (6MWT) with a wearable device. By enrolling 53 patients with cardiac valve diseases in the Department of Cardiovascular Surgery, West China Hospital, Sichuan University, the grouping was based on the presence or absence of PPCs in the postoperative period. The 6MWT continuous respiratory physiological parameters collected by the SensEcho wearable device were analyzed, and the group differences in respiratory parameters and oxygen saturation parameters were calculated, and a prediction model was constructed. The results showed that continuous monitoring of respiratory physiological parameters in 6MWT using a wearable device had a better predictive trend for PPCs in cardiac valve surgery patients, providing a novel reference model for integrating wearable devices with the clinic.

Utilidad del monitoreo continuo del electroencefalograma en el paciente crítico / Utility of continuous electroencephalogram monitoring in the critical patients

Introducción: El monitoreo continuo del Electroencefalograma, es la recogida simultánea de la actividad cerebral y la conducta clínica por un período de horas a días. Por el alto costo de la técnica aún no está muy difundida. Objetivos: Evaluar la utilidad del monitoreo electroencefalográfico continuo en el paciente crítico. Métodos: Se realizó un estudio descriptivo, retrospectivo y longitudinal en 118 sujetos mayores de 19 años ingresados en las unidades de terapia del Hospital Clínico Quirúrgico Hermanos Ameijeiras; entre noviembre 2016 a octubre 2018 con indicación de un Electroencefalograma continuo. Se consideraron variables clínicas y electroencefalográficas: escala de Glasgow, ocurrencia de crisis, diagnóstico, estado al egreso, anormalidad del Electroencefalograma, descargas epileptiformes, sospecha de estatus epiléptico no convulsivo por electroencefalograma entre otras. Los datos se procesaron con test de Chi cuadrado, test de Mc Nemar y test t de student, se empleó un nivel de significación de p≤0.05. Resultados: 60 de los pacientes pertenecían al sexo femenino, la mediana de las edades fue 67,5 años. La escala de Glasgow mostró asociación significativa con el grado de anormalidad del electroencefalograma (p=0,001), es la arreactividad y la discontinuidad de la actividad de base predictores de pobre pronóstico. Se observaron descargas epileptiformes periódicas en 100 pacientes. Se definió estatus epiléptico no convulsivo en 56 sujetos (37,28 por ciento) y en 81 sujetos (68,64 por ciento) el resultado del electroencefalograma motivó una conducta médica. Conclusiones: El monitoreo continuo del electroencefalograma es útil en el diagnóstico y manejo del paciente con episodios no convulsivos, permite formular un pronóstico neurológico y orientó la conducta médica(AU)

Introduction: The continuous monitoring of the electroencephalogram is the simultaneous collection of brain activity and clinical behavior for a period of hours to days. Due to the high cost of the technique, it is not yet widely used. Objectives: To evaluate the usefulness of continuous electroencephalographic monitoring in critically ill patients. Methods: A descriptive, retrospective and longitudinal study was carried out in 118 subjects over 19 years of age admitted to the therapy units at Hermanos Ameijeiras Surgical Clinical Hospital; from November 2016 to October 2018. They were indicated a continuous electroencephalogram. Clinical and electroencephalographic variables were considered, such as Glasgow scale, seizure occurrence, diagnosis, discharge status, electroencephalogram abnormality, epileptiform discharges, suspicion of nonconvulsive status epilepticus by electroencephalogram, among others. The data was processed with the Chi square test, the Mc Nemar test and the student's t test, using significance level of p≤0.05. Results: Sixty patients were female, the median age was 67.5 years. The Glasgow scale showed significant association with the degree of electroencephalogram abnormality (p=0.001). A reactivity and discontinuity of baseline activity are predictors of poor prognosis. Periodic epileptiform discharges were observed in 100 patients. Non-convulsive status epilepticus was defined in 56 subjects (37.28 percent) and in 81 subjects (68.64 percent) the result of the electroencephalogram motivated a medical procedure. Conclusions: The continuous monitoring of the electroencephalogram is useful in the diagnosis and management of patients with non-convulsive episodes, it allows formulating a neurological prognosis and guided medical conduct(AU)

Technical Difficulties in the Implementation of the Continuous Glucose Monitoring System / 中国医疗器械杂志

The continuous glucose monitoring system (CGMS) has been clinically applied to monitor the dynamic change of the subcutaneous interstitial glucose concentration which is a function of the blood glucose level by glucose sensors. It can track blood glucose levels all day along, and thus provide comprehensive and reliable information about blood glucose dynamics. The clinical application of CGMS enables monitoring of blood glucose fluctuations and the discovery of hidden hyperglycemia and hypoglycemia that are difficult to be detected by traditional methods. As a CGMS needs to work subcutaneously for a long time, a series of factors such as biocompatibility, enzyme inactivation, oxygen deficiency, foreign body reaction, implant size, electrode flexibility, error correction, comfort, device toxicity, electrical safety, et al. should be considered beforehand. The study focused on the difficulties in the technology, and compared the products of Abbott, Medtronic and DexCom, then summarized their cutting-edge. Finally, this study expounded some key technologies in dynamic blood glucose monitoring and therefore can be utilized as a reference for the development of CGMS.

Emprego do monitoramento contínuo da floculação no controle de parâmetros de tratabilidade de água / Use of continuous flocculation monitoring in the control of water treatability parameters

RESUMO Neste artigo, empregou-se um equipamento de monitoramento contínuo da floculação (EMCF) para melhor compreensão da coagulação e da floculação no tratamento de águas sintéticas sob diferentes mecanismos de coagulação, em escala de bancada. A água de estudo utilizada nos ensaios foi preparada em laboratório com a adição de uma solução de caulinita em água. Como agente coagulante foi utilizado sulfato de alumínio (SA) líquido, isento de ferro. A resposta do sinal com o tempo mostra três regiões distintas: uma região de crescimento, uma região de patamar e uma região de decaimento. Ao longo do presente trabalho, constatou-se que o índice de floculação (IF) se mostrou adequado para otimizar a floculação tanto pela seleção do pH quanto pela dosagem do coagulante. O pH e as dosagens ótimas, obtidos por meio do ensaio de jarros, estiveram relacionados às maiores variações de IF. O IF médio ( IF ) mostrou-se adequado para antecipar a dosagem ótima a partir de 3 minutos de floculação, e a inclinação da reta de melhor ajuste mostrou-se adequada para estimar a cinética da floculação.

ABSTRACT In this article, a continuous flocculation-monitoring equipment (CFME) was employed to better understand coagulation and flocculation in the treatment of synthetic water under different coagulation mechanisms, on a bench scale. The study water used in the tests was prepared in the laboratory with the addition of a solution of kaolinite in water. Liquid aluminum sulfate, free from iron, was used as a coagulant agent. The flocculation index (FI) measured over time was able to identify the regions of floc growth, plateau and decay. FI was found to be an adequate parameter for optimizing flocculation pH and coagulant dosage. Optimum pH and dosage, obtained in jar tests, were related to the largest variations in FI. The mean FI was found to be adequate for predicting optimum coagulant dosage in the first three minutes after flocculation, whereas the slope of the best-fit FI line was found to be suited for predicting flocculation kinetics.

Efficacy and Safety of Cloud based Continuous Monitoring Systems in Management of Patients in Non-ICU Settings in a Tertiary Care Hospital

Introduction: Continuous monitoring is the most vital aspect in the management of patients in non-ICU settings. Continuous monitoring systems have revolutionized the management of vulnerable patients which alerts the doctors to identify the critical events and intervene timely. In this study, we present our experience of using cloud connected continuous monitoring systems at our hospital. Objectives: To study the efficacy and safety of continuous monitoring systems in the management of patients in a non-ICU setting. Material and methods: A retrospective hospital-based study was conducted in the Acute Medicine ward (AMW) of Ramaiah teaching Hospital, Bangalore. Patients were connected to a cloud based continuous monitoring system for automatic collection and documentation of vital signs. All patients admitted in AMW between September 2017 and January 2018 was included in the study. For comparison, data were collected from September 2016 to January 2017 when the continuous monitoring systems were not implemented. We compared the number of admissions, code blue events. Results: Total of 470 patients in the pre- ICU settings were connected to a continuous monitoring system. There was 88% reduction in the ICU admissions as compared to the previous year. About 11.2% of patients were transferred to ICU and in these patients, continuous monitoring helped the doctors to identify the critical event. There was a significant reduction in code blue events using a continuous monitoring system. There was a significant reduction in medical expenses also. Conclusion: Continuous monitoring reduced the clinical burden on ICU due to the availability of remote monitoring capabilities, and continuous monitoring of reduced medical expenses for patients with improved clinical outcomes.

Effect of real-time continuous monitoring system on serum inflammatory factors and prognosis in patients with sepsis / 中华内分泌外科杂志

Objective To investigate the effect of real-time continuous monitoring system(RT-CGMS)on serum inflammatory factors and prognosis in patients with sepsis.Methods According to the prospective studies,patients were randomly divided into two groups Patients with sepsis were randomly divided into real-time continuous monitoring of blood glucose group and monitoring blood glucose meter group,of which the fasting serum tumor necrosis factor alpha(TNF-α) and interleukin-6(IL-6) and high sensitive C reactive protein (hs-CRP) were detected on the 1st,3rd,7th day.Meanwhile,insulin dosage,incidence of hypoglycemia and mortality rate of 28 days of patients in two groups were recorded,and the above indexes were analyzed.Results TNF-α,IL-6 and hs-CRP in the real-time continuous blood glucose monitoring group were (16.12±2.42)pg/ml、(112.37±17.39)pg/ml and(19.62±2.72)mg/L on the 7th day respectively,while TNF-α,IL-6 and hs-CRP in the blood glucose monitoring group were(23.46±3.12)pg/ml、(140.19±21.48)pg/ml and(25.42±2.54)mg/L on the 7th day,respectively.The decrease of TNF-α,IL-6 and hs-CRP in the continuous blood glucose monitoring group was more significant than that in the blood glucose monitoring group (P＜0.05).Insulin dosage in real-time continuous blood glucose monitoring group was (90.62±15.79)u,hypoglycemia rate was 5.4％,fatality rate was 10.81％ in 28 days of hospitalization,insulin dosage was (130.59±20.65)u,hypoglycemia rate was 22.85％,and fatality rate was 31.42％ in 28 days of hospitalization.There was significant difference between the two groups(P＜0.05).Conclusion For sepsis patients with stress hyperglycemia,a real-time continuous monitoring system combined with insulin therapy can improve the inflammatory response,and control blood glucose effectively as well as reduce mortality.

The exploration of Guardian real-time continuous monitoring system in high-risk infants with hypoglycemia / 中华实用儿科临床杂志

Objective To explore the feasibility of Guardian real-time continuous monitoring system (GRT) in high-risk infants with hypoglycemia.Methods The glucose of 72 infants admitted to Neonatal Intensive Care Unit (NICU) of Children's Hospital of Fudan University between May 2015 and December 2016 were detected by GRT (provided by Medtronic),there were 43 males and 29 females with gestational age [(35.25 ± 4.45) weeks],and birth weight [(2 385.69 ± 1 062.63) g].At the same time,the capillary glucose was monitored intermittently detected by using ACCU-CHEK(R).Results A total of 1 134 paired glucose levels were collected.A good correlation between the paired capillary[(5.23 ± 1.96) mmol/L] and GRT continuous monitor measurements [(5.19 ± 1.99) mmol/L] was found(r =0.88,P ＜ O.05),and the value of mean absolute difference (MAD) was 11.88％.Through the Clarke error grid analysis,there were 98.24 ％ points located in region A and region B,only 20 paired(1.76％) glucose located in region D.Hypoglycemia was defined as glucose concentration ＜ 2.6 mmol/L,while hyperglycemia was defined as glucose concentration ＞ 7.0 mmol/L.A high/low blood glucose detected by peripheral blood glucose monitoring is a high/low blood glucose event,and a high/low blood glucose detected by GRT in a continuous period is a high/low blood glucose event.Twelve cases of hypoglycemia,26 episodes of hypoglycemia,29 cases of hyperglycemia,and 151 episodes of hyperglycemia were detected by using fast blood glucose meter.Twenty-six cases of hypoglycemia,88 episodes of hypoglycemia,38 cases of hyperglycemia,and 229 episodes of hyperglycemia were detected by using GRT.Sixty-two episodes of hypoglycemia were not detected by the fast blood glucose meter,with 14 episodes lasting longer than 30 min,4longer than 60 min,and 5 longer than 90 min.There were 78 hyperglycemic episodes that were not detected by the fast blood glucose meter,with 44 episodes lasting longer than 30 min,15 longer than 60 min,and 70 longer than 90 min.There were significant differences in the testing of hypoglycemia and pathoglycemia(x2 =7.00,18.60;all P ＜ 0.05),but,there was no significant difference in the testing of hyperglycemia between the 2 kinds of detection(x2 =2.26,P ＞0.05).GRT was acceptable to parents,medical staffs and children as only 3 infants bled when the continuous glucose sensor was imbedded,but there was no progressive increase in blood loss.There was no redness,edema,infections,or effusions at the insertion sites.Conclusions The use of GRT continuous monitoring system in high-risk infants of hypoglycemia was feasible.Compared with the conventional intermittent peripheral blood glucose monitoring,more abnormal blood glucose events and their duration could be detected.

Effects of inhaled nitric oxide on hemodynamics and oxygenation in piglets with sepsis / 实用医学杂志

Objective To explore the changes in cardiac index and oxygenation index in sepsis piglets after nitric oxide (NO) gas inhalation. Methods A piglet model of sepsis was induced by intravenous infusion of Gram-negative bacterial endotoxin (LPS), then the piglets were randomly divided into two groups. NO group (n=8) was administered with inhaled nitric oxide of 80ppm via volume control (VC) mechanical ventilation for one hour, while the control group (n = 4) received mechanical ventilation with VC and was observed for one hour to assess the stability of the model. The parameters of oxygenation and hemodynamics were measured by PICCO and arterial blood gas analysis every fifteen minutes for one hour. Results Injection of endotoxin induced a stable pig model of sepsis. PH, HCO3-, arterial oxygen pressure (PaO2), mean arterial pressure (MAP) and cardiac index in this model were significantly lower the baseline values (P < 0.01). Arterial oxygen pressure and cardiac index were significantly higher in N0 group than in the control group (P<0.01). Heart rate (HR), central venous pressure (CVP), global end-diastolic volume index (GEDI) and intrathoracic blood volume index (ITBI) did not significantly differ between NO group and the control group. Conclusions Inhalation of nitric oxide gas can significantly improve oxygenation and cardiac function in piglets with sepsis.

Monitoreo continuo del segmento ST a través del electrograma intracardíaco por un dispositivo cardíaco implantable / Chronic ST-segment monitoring via the intracardiac electrogram for implantable cardiac device / Monitoramento contínuo de segmento ST através de eletrograma intracardíaco de dispositivo cardíaco implantável

La colocación de un dispositivo cardíaco implantable (DCI), ya sea un marcapasos, un cardiodesfibrilador implantable o un dispositivo de terapia de resincronización cardíaca es una práctica cada vez más frecuente en pacientes portadores de insuficiencia cardíaca. Dentro de los avances tecnológicos de los DCI se encuentra la posibilidad de monitorizar los cambios del segmento ST. El monitoreo continuo del segmento ST a través de un electrograma intracardíaco se fundamenta en la importancia que los cambios agudos del segmento ST, frecuentemente, se correlacionan con eventos coronarios clínicamente significativos. El monitoreo del segmento ST a través del Holter ha demostrado ser útil en pacientes asintomáticos con síndromes coronarios, la cual incluye la enfermedad arterial coronaria (EAC), el infarto agudo de miocardio, la angina inestable, así como pacientes sintomáticos con un ECG sin diagnóstico (sin elevación del segmento ST) específico. Concluyendo que para los pacientes con EAC, especialmente post-infarto de miocardio, el monitoreo del segmento ST puede desempeñar un importante papel.

The placement of an implantable cardiac device (ICD), either a pacemaker, an implantable cardioverter defibrillator or a device for cardiac resynchronization therapy is an increasingly common practice in heart failure patients. Within these ICD technological advances is the possibility of monitoring ST segment changes. Continuous ST-segment monitoring via intracardiac electrogram is predicated on the understanding that acute ST changes are frequently correlated with clinically significant coronary events. ST-segment monitoring via Holter ECGs have proven useful for patients who are asymptomatic with coronary syndromes which include coronary artery disease (CAD), acute myocardial infarction, unstable angina, as well as symptomatic patients with a nondiagnostic ECG (no-ST elevation) from standard diagnostic electrocardiograms. Concluding that for patients with CAD, especially post-myocardial infarction, ST segment monitoring can play an important role.

A colocação de um dispositivo cardíaco implantável (DCI), como um marcapassos, um cardioversor-desfibrilador implantável ou um dispositivo para terapia de ressincronização cardíaca é uma prática cada vez mais comum em pacientes com insuficiência cardíaca. Dentro destes avanços tecnológicos do DCI é a capacidade de monitorar as alterações do segmento ST. O monitoramento contínuo do segmento ST, através de um electrograma intracardíaco baseia-se na importância que as alterações agudas no segmento ST, muitas vezes, se correlacionam com eventos coronários clinicamente significativos. O monitoramento do segmento ST através de Holter tem se mostrado útil em pacientes assintomáticos com síndromes coronárias, o que inclui doença arterial coronariana (DAC), infarto agudo do miocárdio, angina instável, e os pacientes sintomáticos com ECG sem diagnostico (sem elevação do segmento ST) específico. Concluindo que os pacientes com DAC, especialmente pós-enfarte do miocárdio, o monitoramento do segmento ST pode desempenhar um papel importante.

The accuracy of real-time continuous monitoring system at different stages and its association with glucose excursion / 中华内分泌代谢杂志

Objective To study the accuracy of real-time continuous monitoring system (RT-CGMS) at different stages and its association with glucose excursion. Methods Totally 33 patients with type 1 diabetes or type 2diabetes were under surveillance of RT-CGMS for 5 d. Capillary glucose values were measured 7 times daily.Correlation coefficient, error grid analysis (EGA), and Bland-Altman analysis methods were used to assess the correlation, accuracy and agreement of RT-CGMS at different stages and in general level; The mean amplitude of glucose excursion (MAGE) and the frequency of glucose excursion ( FGE ) were also calculated. Results ( 1 ) The correlation coefficient of RT-CGMS with capillary glucose values at fasting, postprandial stages, and in general level were 0.94,0.92, and 0.93 respectively( P＜0.01 ). (2) EGA showed that 98.82%, 98.39%, and 98.64% of the results fell in the A and B zones and 1. 18%, 1.61%, and 1.36% fell in the D zone respectively at fasting,postprandial stages, and in general level. There is no result fell in C and E zones. ( 3 ) The agreement analysis showed that RT-CGMS readings were in close agreement with capillary glucose values at fasting, postprandial periods, and in general level. (4)The MAGE at fasting, postprandial periods, and in general level were (3.57±2.66), (4.07±3.09), and (4. 02 ±3.04) mmol/L (P＞0. 05), (0±0. 5), (3± 1), and( 1 ±3) d for FGE (P＜0. 01 ).Conclusion RT-CGMS at fasting stage has higher accuracy than postprandial stage and general level, FGE at fasting stage is higher than postprandial stage and general level.

La saturación venosa de oxigeno en la vena cava superior versus arteria pulmonar en pacientes pediátricos / The oxygen venous saturation in the superior vena cava versus the pulmonary artery in children

Introducción: La monitorización continua de la saturación venosa de oxígeno alerta precozmente sobre serios disturbios en el balance de oxígeno y facilitan las intervenciones terapéuticas oportunas. Objetivo: Identificar la relación entre la saturación de oxígeno de la sangre extraída de la vena cava superior y la de la arteria pulmonar. Método: Se incluyeron en un estudio prospectivo, analítico, descriptivo y observacional 72 pacientes pediátricos, programados para cirugía cardiaca electiva previo consentimiento informado y aprobación del Comité de Ética. Posterior a la inducción de la anestesia general se introdujo un catéter en la vena cava superior. Al finalizar la corrección quirúrgica se determinaron las saturaciones venosas de oxigeno de la vena cava superior y por punción directa de la arteria pulmonar. Los datos fueron procesados estadísticamente y se determinaron las medias y las desviaciones estándar de ambas muestras. Se aplicó la prueba t de Student. Se consideró que existía diferencia o asociación significativa si la probabilidad asociada al test era menor que 0,05 (p<0.05). Resultados: La saturación de oxigeno de las muestras tomadas en ambas localizaciones, no presentan diferencia estadísticamente significativa (p>0.05). Conclusiones: La monitorización continua de la saturación venosa de oxigeno en la vena cava superior se correlaciona con la de la arteria pulmonar en esta serie.

The continuous monitoring of the oxygen venous saturation is an early alert on serious disorders in oxygen balance and allows timely therapeutical interventions. Objective: To identify the relation between oxygen saturation of the blood extracted from the superior vena cava and from the pulmonary artery. Method: An observational, descriptive, analytical and prospective study was conducted in 72 children, programmed for elective cardiac surgery and the written informed consent and the approval of Ethics Committee. After induction of general anesthesia a catheter was passed into the superior vena cava. At the end of surgical correction of the oxygen venous saturations in the above vein were determined and by direct puncture of the pulmonary artery. Data were statistically processed determining the means and the standard deviations (SD) of both samples. The Student t test was applied. Authors considered the existence of a difference or association if the associated likelihood to test was lower than 0,05 (p <0,05). Results: The oxygen saturation of samples took in both locations, has not a significant statistical difference (p > 0.05). Conclusions: The continuous monitoring of the oxygen venous saturation in the superior vena cava is correlated with that of the pulmonary artery in this series.

Continuous glucose monitoring system: dawn period calibration does not change accuracy of the method / Sistema de monitorização contínua de glicose: calibração da madrugada não interfere na acurácia do método

INTRODUCTION: Continuous glucose monitoring system is a valuable instrument to measure glycemic control, which uses a retrospective calibration based upon 3 to 4 capillary glucose meter values inserted by the patient each day. OBJECTIVE: We evaluated the interference of calibration during the dawn period in the system accuracy. METHODS: The monitoring data were retrospectively divided into two groups: with (Group A) or without (Group B) the dawn period calibration (between 1:00 and 5:00 AM). Accuracy of the method was expressed by relative absolute difference. RESULTS: Thirty-four continuous glucose monitoring data were evaluated comprising a total of 112 nights. A total of 289 paired readings were analyzed - 195 in Group A and 94 in Group B. We did not find a difference in relative absolute difference (RAD%) in any analyzed period of day by adding dawn calibration. CONCLUSIONS: These data suggest that dawn calibration does not alter accuracy of method.

INTRODUÇÃO: O CGMS (sigla do inglês continuous glucose monitoring system) é um instrumento valioso no controle glicêmico e utiliza uma calibração por meio de 3 ou 4 medidas de glicemia capilar inseridas pelo paciente em cada dia do exame. OBJETIVO: Avaliar a interferência da calibração durante a madrugada na acurácia do sistema. MÉTODOS: Os dados das monitorizações foram divididos retrospectivamente em dois grupos: com (Grupo A) ou sem (Grupo B) a calibração da madrugada (entre 1:00 e 5:00 AM). A acurácia do método foi mostrada pela diferença relativa absoluta (DRA por cento). RESULTADOS: Trinta e quarto dados de monitorização foram avaliados em um total de 112 noites. Um total de 289 leituras pareadas foi analisado - 195 no Grupo A e 94 no Grupo B. Não foi encontrada diferença em DRA% em nenhum período do dia quando adicionada a calibração durante a madrugada. CONCLUSÕES: Esses dados sugerem que a calibração da madrugada não altera a acurácia do método.

An assay for the determination of alkaline phosphatase activity using disodium p-acetylphenylphosphate as a substrate / 临床检验杂志

Objective To establish a new method to measure alkaline phosphatase (ALP) activity using disodium p-acetylphenylphosphate (PAP-PNa2) as substrate.Methods Experimental parameters were set up with continuous-monitoring procedures on a semiautomatic analyzer.Results The wavelength of maximum absorption of PAP was 325 nm,and the Km of ALP was 0.376 mmol/L.The molecular extinction coefficient of PAP at 340 nm was 23 390 L?mol-1?cm-1 and the concentration of citrate buffer was 0.438 mol/L.In the measurement,the optimum pH was 10.4,and the optimum concentration of substrate was 5.0 mmol/L.The delay time was 60 sec and the time keeping the linear reaction was 15 min,and the linear range was 0~1 110 U/L.The measurement was not interfered by the hemoglobin

The Clinical Relevance of Four-Day Blood Cultures with the BACTEC 9240 System / 대한임상병리학회지

BACKGROUND: It is well established that automated blood culture systems require no more than five days of incubation for the detection of the majority of pathogens. It is not clear, however, whether continuous monitoring of blood culture systems also routinely require five days of incubation. This study was conducted to determine the clinical impact of incubating blood cultures for 4 days rather than for 5 days using the BACTEC 9240 blood culture system. METHODS: During the 6-month period from July to November 1998, 22,167 blood cultures were performed. Positive culture sets and the isolates were sorted by times to detection of isolates. Chart reviews were done for isolates detected on day 3 or later to determine whether therapy was changed due to this blood culture result. RESULTS: Of 2,426 isolates (2,319 positive cultures), 2,344 (96.6%) were recovered within 3 days and 52 (2.1%) were recovered on day 4, and 30 (1.2%) on day 5. Chart reviews showed that 21 of the 52 isolates detected on day 4 were considered clinically significant and 10 of those affected the treatment of the patients. On day 5, 5 of the 30 isolates were considered clinically significant and 3 of those affected the treatment. CONCLUSIONS: Four-days rather than a 5-day incubation period reduced culture sensitivity by 1.2% but most of those were clinically irrelevant. These data suggest that the 4-day protocol for the BACTEC 9240 system is adequate for detection of positive blood cultures.

Evaluation of Terminal Subcultures for Blood Cultures Monitored by VITAL System / 대한임상병리학회지

BACKGROUND: Many non-invasive, continuous-monitoring blood culture systems have introduced technology that reduces the time and labor. There is a report that terminal subculture is necessary to decrease false negative. The purpose of this study is to evaluate the terminal subcultures for blood cultures monitored by VITAL system and to determine the clinical significance of positive blood cultures not detected by VITAL system. METHODS: From June to August 1996, a total of 3,988 blood culture bottles were processed by VITAL system and terminal subcultures were performed on consecutive 5 day blood culture. Any culture that was instrument positive but negative upon terminal subculture was considered to be false positive. Any culture that was instrument negative but positive upon terminal subculture was considered to be false negative. And false negative were categorized into minor and major errors. RESULTS: Two-hundred and nineteen (5.5%) out of 3,988 blood culture bottles were signaled as positive by VITAL system. Twenty-four bottles out of 219 were VITAL positive but negative upon terminal subcultures (false positive rate, 0.8%). And seven of the 3,988 terminal subcultures were false negative (0.2%). Four out of seven were major error and three were minor error. The isolates of major error bottles were Staphylococcus spp. and minor error bottles were Escherichia coli and Candida tropicalis. These isolates were clinically significant pathogens, but there were no changes on antimicrobial chemotherapy after reporting the positive blood culture reports. CONCLUSIONS: These results suggest that using VITAL system, terminal subculture of 5 day instrument-negative blood culture bottles is not necessary and the VITAL system provides for the rapid and convenient tool for detecting bacteremia.