Aortic pressure and forward and backward wave components in children, adolescents and young-adults: Agreement between brachial oscillometry, radial and carotid tonometry data and analysis of factors associated with their differences.

Non-invasive devices used to estimate central (aortic) systolic pressure (cSBP), pulse pressure (cPP) and forward (Pf) and backward (Pb) wave components from blood pressure (BP) or surrogate signals differ in arteries studied, techniques, data-analysis algorithms and/or calibration schemes (e.g. calibrating to calculated [MBPc] or measured [MBPosc] mean pressure). The aims were to analyze, in children, adolescents and young-adults (1) the agreement between cSBP, cPP, Pf and Pb obtained using carotid (CT) and radial tonometry (RT) and brachial-oscillometry (BOSC); and (2) explanatory factors for the differences between approaches-data and between MBPosc and MBPc.1685 subjects (mean/range age: 14/3-35 y.o.) assigned to three age-related groups (3-12; 12-18; 18-35 y.o.) were included. cSBP, cPP, Pf and Pb were assessed with BOSC (Mobil-O-Graph), CT and RT (SphygmoCor) records. Two calibration schemes were considered: MBPc and MBPosc for calibrations to similar BP levels. Correlation, Bland-Altman tests and multiple regression models were applied. Systematic and proportional errors were observed; errors´ statistical significance and values varied depending on the parameter analyzed, methods compared and group considered. The explanatory factors for the differences between data obtained from the different approaches varied depending on the methods compared. The highest cSBP and cPP were obtained from CT; the lowest from RT. Independently of the technique, parameter or age-group, higher values were obtained calibrating to MBPosc. Age, sex, heart rate, diastolic BP, body weight or height were explanatory factors for the differences in cSBP, cPP, Pf or Pb. Brachial BP levels were explanatory factors for the differences between MBPosc and MBPc.

Is the Measurement of Blood Pressure by Automatic Monitor in the South American Pediatric Population Accurate? SAYCARE Study.

OBJECTIVE: This study aimed to test the validity of an automatic oscillometric device to measure the blood pressure (BP) in children (n = 191) and adolescents (n = 127) aged 3 to 18 years. METHODS: Systolic BP (SBP) and diastolic BP (DBP) levels were measured simultaneous by automatic device and mercury column with Y-connection. To verify the validity, Bland-Altman plots and limits of agreement of 95% (95% LOA), specificity and sensitivity of the device, and the grade of British Hypertension Society (BHS) criteria were used. RESULTS: The monitor measurements demonstrated lower measurement bias (mean difference [95% LOA]): 1.4 (-9.9 to 12.8) mmHg in children and 4.3 (-7.8 to 16.5) mmHg in adolescents for SBP. For DBP, it was 2.2 (-7.4 to 11.7) mmHg in children and 1.4 (-8.4 to 11.1) mmHg in adolescents. The sensitivity in children was 21.4 (95% CI = 16.3-26.6), and in adolescents, it was 20.0 (95% CI = 13.2-26.8); the specificity was 95.9 (95% CI = 93.4-98.4) in children and 100.0 (95% CI = 100.0-100.0) in adolescents. The monitor-tested ratings are Grade B for SBP in children and SBP and DBP in adolescents and Grade C for DBP in children. CONCLUSIONS: The automatic monitor presented high values of specificity and lower values of sensitivity to the diagnosis of HBP; however, it can be considered accurate (lower measurement bias) and valid for epidemiological and clinical practice in accordance with BHS criteria.

Validation of the Omron HEM 742 blood pressure monitoring device in adolescents.

BACKGROUND: Accurate blood pressure measurement is fundamental for scientific investigation or clinical decision-making. In this sense, it is important to verify the values provided by electronic devices. OBJECTIVE: To validate the Omron HEM 742 blood pressure monitoring device in adolescents according to criteria suggested by the British Hypertension Society. METHODS: A total of 150 adolescents aged between 10 and 16 years participated in the study. The automated Omron HEM 742 monitor was connected in Y to the mercury column auscultatory device, then three simultaneous measurements were taken, and the differences between the readings of the two devices were calculated. The intraclass correlation coefficient and Bland-Altman plot (agreement) were used to verify the relationship between both devices. Specificity and sensitivity of the device were determined by using the ROC curve. RESULTS: The comparison between the measurements showed an equal to or lower than 5mmHg difference in 67.3% of the systolic values, and 69.3% of the diastolic values; an equal to or lower than 10mmHg difference occurred in 87.3% and 90.6% of the systolic and diastolic values, respectively; an equal to or lower than 15mmHg difference was found in 96.6% of the systolic values and 97.3% of the diastolic values. These findings are consistent with a grade A according to the British Hypertension Society protocol. A marked consonance was observed between the values obtained by the automated monitor and this device was proven to be capable of identifying the presence or absence of high blood pressure. CONCLUSION: The Omron HEM 742 monitor was proved valid for blood pressure measurement in adolescents according to the criteria suggested by the British Hypertension Society.

Validação do monitor de medida de pressão arterial Omron HEM 742 em adolescentes / Validación del monitor de medida de presión arterial Omron HEM 742 en adolescentes / Validation of the omron HEM 742 blood pressure monitoring device in adolescents

FUNDAMENTO: A medida precisa da pressão arterial é fundamental para a investigação científica ou decisão clínica. Nesse sentido, é importante verificar valores fornecidos por equipamentos eletrônicos. OBJETIVO: Validar o monitor Omron HEM 742 de medida de pressão arterial em adolescentes, segundo os critérios sugeridos pela British Hypertension Society. MÉTODOS: Participaram do estudo 150 adolescentes com idades entre 10 e 16 anos. O monitor automático Omron HEM 742 foi conectado em Y com equipamento auscultatório de coluna de mercúrio, e realizaram-se três avaliações simultâneas, calculando-se as diferenças entre os dois equipamentos. Para verificar a relação entre ambos, utilizaram-se o coeficiente de correlação intraclasse e a plotagem de Bland-Altman (concordância). A especificidade e a sensibilidade do aparelho foram determinadas pela curva ROC. RESULTADOS: A comparação entre as medidas acusou uma diferença menor ou igual a 5 mmHg em 67,3 por cento dos valores sistólicos e 69,3 por cento dos valores diastólicos; uma diferença menor ou igual a 10 mmHg ocorreu em 87,3 por cento e 90,6 por cento dos valores sistólicos e diastólicos, respectivamente; e uma diferença menor ou igual a 15 mmHg em 96,6 por cento dos valores sistólicos e 97,3 por cento dos diastólicos. Esses resultados indicam grau A segundo o protocolo da British Hypertension Society. Observou-se ainda elevada concordância nos valores obtidos por meio do monitor automático, e verificou-se que esse equipamento é capaz de identificar a presença ou a ausência da pressão arterial elevada. CONCLUSÃO: O monitor Omron HEM 742 mostrou-se válido para medidas de pressão arterial em adolescentes, conforme os critérios sugeridos pela British Hypertension Society.

BACKGROUND: Accurate blood pressure measurement is fundamental for scientific investigation or clinical decision-making. In this sense, it is important to verify the values provided by electronic devices. OBJECTIVE: To validate the Omron HEM 742 blood pressure monitoring device in adolescents according to criteria suggested by the British Hypertension Society. METHODS: A total of 150 adolescents aged between 10 and 16 years participated in the study. The automated Omron HEM 742 monitor was connected in Y to the mercury column auscultatory device, then three simultaneous measurements were taken, and the differences between the readings of the two devices were calculated. The intraclass correlation coefficient and Bland-Altman plot (agreement) were used to verify the relationship between both devices. Specificity and sensitivity of the device were determined by using the ROC curve. RESULTS: The comparison between the measurements showed an equal to or lower than 5mmHg difference in 67.3 percent of the systolic values, and 69.3 percent of the diastolic values; an equal to or lower than 10mmHg difference occurred in 87.3 percent and 90.6 percent of the systolic and diastolic values, respectively; an equal to or lower than 15mmHg difference was found in 96.6 percent of the systolic values and 97.3 percent of the diastolic values. These findings are consistent with a grade A according to the British Hypertension Society protocol. A marked consonance was observed between the values obtained by the automated monitor and this device was proven to be capable of identifying the presence or absence of high blood pressure. CONCLUSION: The Omron HEM 742 monitor was proved valid for blood pressure measurement in adolescents according to the criteria suggested by the British Hypertension Society.

FUNDAMENTO: La medida precisa de la presión arterial es fundamental para la investigación científica o decisión clínica. En este sentido, es importante que se verifique valores provenientes de equipos electrónicos. OBJETIVO: Validar el monitor Omron HEM 742 de medida de presión arterial en adolescentes, de acuerdo con los criterios sugeridos por British Hypertension Society. MÉTODOS: Participaron del estudio 150 adolescentes con edades entre 10 y 16 años. Se conectó el monitor automático Omron HEM 742 en Y con equipo de auscultación de columna de mercurio, y se realizaron tres evaluaciones simultáneas, calculándose las diferencias entre los dos equipos. Para verificarse la relación entre ambos, se utilizó el coeficiente de correlación intraclase y el método de Bland-Altman (concordancia). Se determinó la especificidad y la sensibilidad del aparato por medio de la curva ROC. RESULTADOS: La comparación entre las medidas evidenció una diferencia menor o igual a 5 mmHg en el 67,3 por ciento de los valores sistólicos y el 69,3 por ciento de los valores diastólicos; una diferencia < a 10 mmHg ocurrió en el 87,3 por ciento y el 90,6 por ciento de los valores sistólicos y diastólicos, respectivamente; y una diferencia < a 15 mmHg en el 96,6 por ciento de los valores sistólicos y el 97,3 por ciento de los diastólicos. Esos resultados indican grado A según el protocolo de British Hypertension Society. Se observó aún elevada concordancia en los valores obtenidos por medio del monitor automático, y se verificó que este equipo es capaz de identificar la presencia o la ausencia de la presión arterial elevada. CONCLUSIÓN: El monitor Omron HEM 742 se mostró válido para medidas de presión arterial en adolescentes, de acuerdo con los criterios sugeridos por British Hypertension Society.

An evaluation of the Rastreometro, a new device for populational screening for high blood pressure in developing countries.

OBJECTIVE: To test a simplified blood pressure device called Rastreometro that could be used by the Health Agents. METHODS: The Rastreometro has been developed from an ordinary aneroid sphygmomanometer, in which the numeric display is covered by an adhesive with a red zone, indicating pressures equal or above 140 mmHg and a yellow zone indicating pressures below 140 mmHg. The onset of oscillations of the aneroid needle is taken as an indication of the systolic pressure value. The measurements made by the Rastreometro were compared with those made by the auscultatory method, and were carried out in 268 patients, by two operators. The influence on the results of confounding variables such as age, gender, BMI, arm length, upper arm circumference, skin colour and antihypertensive treatment were taken into consideration, as well as intra and interobserver variation. RESULTS: In the whole group, sensitivity was 95.1%, specificity was 63.1%, positive predictive value was 62.4% and negative predictive value was 95.3%. Hypertensive treatment significantly affected specificity, 32.7% as compared to 77.8% for the non-treated group. Both operators improved their results over time. CONCLUSION: This study suggests that the Rastreometro technique, as a screener for hypertension, has good sensitivity. Concerning specificity, it is acceptable, provided the patient is not on regular antihypertensive treatment. In this latter situation, it can be improved by a proper standardization of the method to read the systolic pressure by needle oscillations. Furthermore, the use of this technique requires well trained operators.

Uma avaliação do rastreômetro, um novo equipamento para triagem populacional da pressão arterial elevada, em países em desenvolvimento / An evaluation of the rastreometro, a new device for populational screening for high blood pressure in developing countries / An evaluation of the rastreometro, a new device for populational screening for high blood pressure in developing countries

OBJETIVO: Testar um novo dispositivo simplificado de medição chamado rastreômetro, que poderia ser usado pelos Agentes de Saúde. MÉTODOS: O rastreômetro foi desenvolvido a partir de um esfigmomanômetro aneróide convencional, no qual se cobriu o visor do aneróide com um adesivo, cujo desenho tem uma faixa vermelha, indicativa de pressões > 140 mmHg e uma faixa amarela, indicativa de pressões < 140 mmHg. O início das oscilações da agulha do esfigmomanômetro é considerado indicativo da pressão arterial sistólica. As medições pelo rastreômetro foram comparadas com aquelas realizadas pelo método auscultatório em 268 pacientes, por dois operadores. A influência, sobre os resultados, de variáveis que podem causar confusão, como idade, sexo, IMC, comprimento do braço, circunferência do braço, cor da pele e presença de tratamento anti-hipertensivo, foram levadas em consideração, assim como a variação intra e interobservador. RESULTADOS: No grupo como um todo, a sensibilidade foi de 95,1 por cento, a especificidade foi de 63,1 por cento, o valor preditivo positivo foi de 62,4 por cento e o valor preditivo negativo foi de 95,3 por cento. O tratamento anti-hipertensivo afetou significativamente a especificidade, de 32,7 por cento, em comparação com 77,8 por cento, no grupo não medicado. Os dois operadores melhoraram seus resultados ao longo do tempo. CONCLUSÃO: Este estudo sugere que a técnica do rastreômetro, como método de triagem para hipertensão, tem boa sensibilidade. Quanto à especificidade, ela é aceitável se os pacientes não estiverem sob tratamento anti-hipertensivo regular. Nesse último caso, pode ser melhorada pela padronização adequada da leitura da pressão sistólica pelas oscilações da agulha. Além disto, o uso dessa técnica requer operadores bem treinados.

OBJECTIVE: To test a simplified blood pressure device called Rastreometro that could be used by the Health Agents. METHODS: The Rastreometro has been developed from an ordinary aneroid sphygmomanometer, in which the numeric display is covered by an adhesive with a red zone, indicating pressures equal or above 140 mmHg and a yellow zone indicating pressures below 140 mmHg. The onset of oscillations of the aneroid needle is taken as an indication of the systolic pressure value. The measurements made by the Rastreometro were compared with those made by the auscultatory method, and were carried out in 268 patients, by two operators. The influence on the results of confounding variables such as age, gender, BMI, arm length, upper arm circunference, skin colour and antihypertensive treatment were taken into consideration, as well as intra and interobserver variation. RESULTS: In the whole group, sensitivity was 95.1 percent, specificity was 63.1 percent, positive preditive value was 62.4 percent and negative preditive value was 95.3 percent. Hypertensive treatment significantly affected specificity, 32.7 percent as compared to 77.8 percent for the non-treated group. Both operators improved their results over time. CONCLUSION: This study suggests that the Rastreometro technique, as a screener for hypertension, has good sensitivity. Concerning specificity, it is acceptable, provided the patient is not on regular antihypertensive treatment. In this latter situation, it can be improved by a proper standardization of the method to read the systolic pressure by needle oscillations. Furthermore, the use of this technique requires well trained operators.

Can aneroid sphygmomanometers be used at altitude?

Mercury-independent devices are increasingly being used in clinical practice as mercury will soon be removed from clinical use as a result of environmental, health and safety concerns. The aim of this study was to evaluate the accuracy of a portable aneroid device in an adult population at high altitude by following the part of the protocol of the British Hypertension Society regarding comparison between device and observer. We examined 10 subjects in Cerro de Pasco, Peru, which is situated 4370 m above sea level. The aneroid device was initially calibrated at both high altitude and at sea level to ensure optimal function. Validation of the device was undertaken at high altitude by connecting it in parallel to two mercury sphygmomanometers. Eleven sequential same-arm measurements were taken from each subject by two trained observers, alternating between mercury sphygmomanometry and the aneroid device. Simultaneous mercury readings were also recorded for additional analysis. During calibration, all 60 comparisons between the aneroid and mercury sphygmomanometers were within 3 mm Hg both at sea level and at high altitude. At validation, the device achieved an A grade for both systolic and diastolic pressures and also fulfilled the requirements of the Association for the Advancement of Medical Instrumentation. The mean and standard deviation for systolic and diastolic pressures, respectively, were -1.32 (4.3) mm Hg and 3.7 (4.7) mm Hg in sequential analysis and -0.7 (2.6) mm Hg and -3.3 (2.7) mm Hg in simultaneous analysis. We conclude that the Riester-Exacta portable aneroid device can be recommended for use in an adult population at high altitude.

Clinical evaluation of the Braun BP 3000 Easy Click according to the ANSI/AAMI SP 10:2002.

BACKGROUND: Home blood pressure monitoring has been increasingly encouraged as a supplement to measurements in the clinic in the 2003 European Society of Hypertension-European Society of Cardiology and in the Seventh Joint National Committee guidelines. Before marketing, however, blood pressure measuring devices for self-blood pressure monitoring should be independently validated. OBJECTIVE: The main objective of the present study was to examine the clinical accuracy of the Braun BP 3000 (Braun GmbH, Kronberg, Germany) wrist blood pressure measurement device. METHODS: Measurements of systolic and diastolic blood pressure in normotensive and hypertensive individuals were obtained using the mercury sphygmomanometer and the Braun BP 3000 equipment. Repeated sequential blood pressure single-arm measurements comparing the test device and the standard mercury sphygmomanometer were completed according to the American National Standard Institution (ANSI)/Association for the Advancement of Medical Instrumentation (AAMI) SP 10:2002 Protocol Guidelines on 90 study participants (270 measurements with each pressurometer). RESULTS: The equipment passed the test of systolic blood pressure measurements for method 1 (270 measurements treated separately) and method 2 (mean values of three observations on 90 patients). The mean+/-SD value was -2.01+/-5.61 (upper limit 5+/-8) and -2.01+/-4.41 (upper limit 2.01+/-6.65), respectively. The device also passed the diastolic blood pressure measurement requirements as the mean+/-SD value for method 1 was -0.97+/-5.52 (upper limit 5+/-8) and for method 2 was -0.97+/-4.87 (upper limit 0.97+/-6.87), respectively. CONCLUSIONS: The data from this study show that the Braun BP 3000 successfully passed the ANSI/AAMI SP 10:2002 requirements.

Peripheral arterial blood pressure monitoring adequately tracks central arterial blood pressure in critically ill patients: an observational study.

INTRODUCTION: Invasive arterial blood pressure monitoring is a common practice in intensive care units (ICUs). Accuracy of invasive blood pressure monitoring is crucial in evaluating the cardiocirculatory system and adjusting drug therapy for hemodynamic support. However, the best site for catheter insertion is controversial. Lack of definitive information in critically ill patients makes it difficult to establish guidelines for daily practice in intensive care. We hypothesize that peripheral and central mean arterial blood pressures are interchangeable in critically ill patients. METHODS: This is a prospective, observational study carried out in a surgical-medical ICU in a teaching hospital. Fifty-five critically ill patients with clinical indication of invasive arterial pressure monitoring were included in the study. No interventions were made. Simultaneous measurements were registered in central (femoral) and peripheral (radial) arteries. Bias and precision between both measurements were calculated with Bland-Altman analysis for the whole group. Bias and precision were compared between patients receiving high doses of vasoactive drugs (norepinephrine or epinephrine >0.1 microg/kg/minute or dopamine >10 microg/kg/minute) and those receiving low doses (norepinephrine or epinephrine <0.1 microg/kg/minute or dopamine <10 microg/kg/minute). RESULTS: Central mean arterial pressure was 3 +/- 4 mmHg higher than peripheral mean arterial pressure for the whole population and there were no differences between groups (3 +/- 4 mmHg for both groups). CONCLUSION: Measurement of mean arterial blood pressure in radial or femoral arteries is clinically interchangeable. It is not mandatory to cannulate the femoral artery, even in critically ill patients receiving high doses of vasoactive drugs.

[Evaluation of the Omron 705-CP blood pressure measuring device for use in adolescents and young adults]. / Avaliação do monitor de medida de pressão arterial OMRON 705-CP para uso em adolescentes e adultos jovens.

OBJECTIVE: To assess the Omron 705-CP monitor for measuring blood pressure in adolescents and young adults. METHODS: According to the protocols of the British Hypertension Society and the Association for the Advancement of Medical Instrumentation, we performed validation of the device in 60 adolescents. The Omron monitor was connected in Y to a mercury column. Four consecutive and simultaneous measurements were taken with the mercury column sphygmomanometer and the test device, were independently analyzed, and the mean differences between the blood pressure measurements and the standard deviations of those differences were calculated. The results were analyzed according to the grading system of the protocol used. RESULTS: Two hundred and forty measurements were evaluated. The mean age of the patients was 16.3 years. When the measurement performed with the mercury column sphygmomanometer was compared with that taken with the device, a difference < or =15 mmHg was observed in 97.9% of the systolic and 98.8% of the diastolic blood pressure measurements; a difference < or =10 mmHg was observed in 86.3% of the systolic and 90.4% of the diastolic blood pressure measurements, which was classified as grade A; a difference < or =5 mmHg was observed in 59.1% of the systolic and 67% of the diastolic blood pressure measurements, and was classified as grade A/B. The mean difference and the standard deviation of that difference for the systolic blood pressure was 2.91+/-6.42 mmHg, and, for the diastolic blood pressure, it was 1.16+/-5.79 mmHg. CONCLUSION: The Omron 705-CP monitor proved to be useful for measuring blood pressure in adolescents according to the protocol used.

Avaliação do monitor de medida de pressão arterial 0mron 705-CP para uso em adolescentes e adultos jovens / Evaluation of the Omron 705-CP blood pressure measuring device for use in adolescents and young adults

OBJETIVO: Avaliar o monitor OMRON 705-CP de medida de pressão arterial em adolescentes e adultos jovens. MÉTODOS: De acordo com o protocolo da British Hypertension Society e da Association for the Advancement of Medical Instrumentation, realizamos a validação do aparelho em 60 adolescentes. O monitor foi conectado em Y com a coluna de mercúrio e foram realizadas 4 medidas consecutivas e simultâneas, analisadas as independentes e calculadas as diferenças médias entre as pressões e o desvio padrão dessas diferenças. Os resultados foram analisados de acordo com o sistema de grau do protocolo utilizado. RESULTADOS: Foram avaliadas 240 medidas. A idade média dos pacientes foi 16,3 anos. Quando comparada a medida realizada pela coluna de mercúrio com o aparelho houve uma diferença < 15 mmHg em 97,9 por cento das medidas sistólicas e 98,8 por cento das diastólicas; uma diferença < 10 mmHg em 86,3 por cento das medidas sistólicas e 90,4 por cento das diastólicas, classificada como grau A; uma diferença < 5 mmHg em 59,1 por cento das medidas sistólicas e 67 por cento das medidas diastólicas, considerada pela classificação entre A/B. A diferença média e o desvio padrão dessa diferença na pressão sistólica foi de 2,91±6,42 mmHg e para a diastólica de 1,16±5,79 mmHg. CONCLUSAO: O monitor OMRON 705-CP mostrou-se válido para medidas de pressão arterial de adolescentes segundo o protocolo empregado.

A comparative study of sphygmomanometers at the Port-of-Spain General Hospital and the St. Clair Medical Centre - abstract

The accuracy and working condition of 65 sphygmomanometers were tested: 32 mercury and 21 aneroid models were used at the Port-of-Spain General Hospital and 12 mercury only units at the St. Clair Medical Centre. Faults in the inflation-deflation system were common and caused mainly by leakage at the inlet of control valves or at connections. The accuracy of the gauges was examined at 90 and 160mm Hg. Six per cent of the mercury and 67 percent of the aneroid models at the Port-of-Spain General Hospital had errors >+/- 4 mm Hg. At the St. Clair Medical Centre, using the same standard procedures, 8 percent of the mercury were found to have errors. Most of the cuffs examined (>50 percent) had a bladder dimension which did not meet the recommendations of the American Heart Association - 13 x 24 cm. Mercury sphygmomanometers should be bought in preference to aneroid models because they are more accurate, less expensive in the long-term and easily maintained. They should be checked every 6 - 12 months depending upon usage. Replacement parts should be readily available (AU)