Princípios analíticos da gasometria arterial / Analytical principles of arterial gasometry

Gasometria arterial (GA) é um exame que permite avaliar a condição respiratória e metabólica do paciente, sendo uma das formas mais comuns de investigação clínica em casos emergenciais e de cuidados críticos. É utilizada para medir as concentrações de oxigênio e também para avaliação do distúrbio do equilíbrio ácido-base, da oxigenação do sangue arterial e da ventilação alveolar. O presente estudo tem como objetivo apontar e avaliar os princípios da técnica de gasometria arterial, fases analíticas, principais doenças em que se utiliza o exame e inovações da técnica ao longo dos anos, baseado em dados de artigos científicos e banco de dados do Scielo (Scientific Eletronic Library Online) e Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde). A coleta de sangue arterial para gasometria ocorre através de um procedimento invasivo realizado por intermédio de uma punção arterial. Tal procedimento é executado pelo profissional enfermeiro e exige qualificações técnicas e científicas. O estudo mostrou que as informações acerca do exame constituem uma importante ferramenta para que se possam compreender a complexidade da técnica bem como os distúrbios ácido-base envolvidos na clínica do paciente.

Arterial blood gas (GA) is an exam that allows the assessment of respiratory and metabolic condition, being one of the most common forms of clinical investigation in emergency cases and critical care. It is used to measure oxygen concentrations, as well as for evaluation of acid-base balance disorder, arterial blood oxygenation and alveolar ventilation. This study aims to point out and evaluate the principles of arterial blood gas technique, analytical phases, main diseases in which the examination is used and innovations of the technique over the years, based on data from scientific articles and SciELO database (Scientific Electronic Library Online) and Lilacs (Latin American and Caribbean Health Sciences Literature). The collection of arterial blood for blood gas analysis occurs through an invasive procedure in which an arterial puncture is performed. Such procedure is performed by the professional nurse and requires technical and scientific qualifications. The study showed that the information about the exam is an important tool to understand the complexity of the technique, as well as the acid-base disorders involved in the patient's clinic.

Monitoreo de pulsioximetría en extracciones dentales bajo protocolo de exodoncia simple y quirúrgico / Pulse oximetry measure in dental extractions under simple and surgical exodoncy protocol

INTRODUCCIÓN. El uso de un oxímetro como método de monitoreo no invasivo para el paciente permite al profesional odontólogo detectar, evaluar y prevenir situaciones de urgencia. OBJETIVO. Analizar la pulsioximetría en pacientes atendidos por extracciones dentales en el Centro Quirúrgico de la Facultad de Odontología de la Universidad Central del Ecuador. MATERIALES Y MÉTODOS. Estudio observacional, descriptivo realizado a 30 pacientes bajo protocolo de exodoncia quirúrgica y 30 bajo protocolo de exodoncia simple; a los cuales se monitoreó constantes vitales con pulsioxímetro, los datos se pro-cesaron con el programa estadístico International Business Machines Statistical Package for the Social Sciences Versión 2.0 para determinar varianza a través de distribución de frecuencias, medias, desviación estándar, pruebas de T Student y Anova. RESULTADOS. Existió mayor alteración en pulso durante la fase de exodoncia en ambos protocolos de atención, mientras que la saturación de oxígeno aumentó desde la fase de anestesia, sin tener varianzas significativas. Las mujeres presentaron valores elevados de saturación de oxígeno 95,5% y pulso (87,07 ± 1,39 latidos por minuto) en comparación con los hombres durante todas las fases de ambos protocolos. Existieron variaciones significativas de pul-so en pacientes sometidos a exodoncias quirúrgicas con ansiedad leve o nula mientras que en exodoncia simple existió mayor varianza de pulso en aquellos con ansiedad mode-rada según la Escala de Ansiedad de Corah. Se presentaron cuatro urgencias 6,66% (4; 60). CONCLUSIÓN. El monitoreo constante mediante el pulsioxímetro durante la atención odontológica permitió identificar a tiempo eventos que hubiesen comprometido la integri-dad del paciente y evitar que se conviertan en emergencia.

INTRODUCTION. The use of an oximeter as a non-invasive monitoring method for a pa-tient, allows dentist to detect, evaluate and prevent emergency situations. OBJECTIVE. Analyze the pulse oximetry in patients attended for dental extractions in the Faculty of Dentistry ́s Surgical Center at the Universidad Central del Ecuador. MATERIALS AND ME-THODS. Observational, descriptive study of 30 patients treated under surgical exodontics protocol and 30 under simple exodontics protocol.Vital signs were measured with pulse oximeter and the data was processed with the International Business Machines Statistical Package for the Social Sciences Version 2.0 to determine the variance through distribution of frequencies, means, standard deviation, Student T tests and Anova. RESULTS. The-re was a greater alteration in pulse, during the exodontic phase in both protocols, while oxygen saturation increased at the anesthesic phase, without having relevant variances. Women patients have increased values of oxygen saturation (95,5%) and pulse (87,07 ± 1,39 beats per minute) compared to men during all phases of both protocols. There were significant pulse variations in patients who had surgical extractions with mild level anxiety. In the other hand, in simple extractions, there was greater pulse variance in patients who have moderate anxiety according to the Corha Anxiety Scale. During the study four ur-gencies 6,66% (4; 60) were identified. CONCLUSION. Constant monitoring by the pulse oximeter during dental care, allowed to identify events that might have compromised the integrity of the patient, in order to prevent and avoid they become an emergency situation.

Algoritmo para la detección de puntos clínicos de interés de la onda de pulso arterial / Algorithm for the detection of clinical points of interest of the arterial pulse wave

Introducción: La aplicación de métodos para la detección de puntos clínicos de interés de la onda de pulso permite la obtención de parámetros como el índice de rigidez vascular y el de reflexión que facilitan la evaluación de los efectos vasculares del envejecimiento, la hipertensión y la aterosclerosis. Por esto es necesaria la adecuada localización del inicio, pico sistólico, incisura dicrota y el pico diastólico de la onda de pulso arterial. Objetivo: Desarrollar un algoritmo para la localización del inicio, pico sistólico, incisura dicrota y el pico diastólico de la onda de pulso arterial. Método: El algoritmo presentado utiliza la primera derivada unido a condicionales móviles para eliminar puntos no deseados, al igual que intervalos no confiables. El algoritmo fue evaluado utilizando la anotación de un experto, con 5 registros de onda de pulso arterial de 5 minutos (5236 anotaciones) y contaminadas a diferente relaciones señal ruido (15, 12 and 9 dB). Resultados: Cuando se comparó con las anotaciones de un experto el algoritmo detecto estos puntos fiduciales con una sensibilidad promedio, predictividad positiva y exactitud del 100 por ciento y mostró errores menores de 10ms. En señales de onda de pulso arterial contaminadas con ruido en ambos casos el error relativo fue menor que 2 por ciento respecto a un periodo de muestreo de 800ms. Conclusiones: el algoritmo provee una simple pero precisa detección de los puntos clínicos de interés de la onda de pulso arterial, robusto a ruido y artefactos de movimiento que pudiera ser utilizado en la evaluación del índice de rigidez y de reflexión vascular(AU)

Introduction: The application of methods for the detection of clinical points of interest of the pulse wave allows obtaining parameters such as the index of vascular rigidity and reflection that facilitate the evaluation of the vascular effects of aging, hypertension and atherosclerosis. For this reason, the appropriate localization of the onset, systolic peak, dicrotic notchs and the diastolic peak of the arterial pulse wave is necessary. Objective: To develop an algorithm for the localization of the onset, systolic peak, dicrotic notchs and the diastolic peak of the arterial pulse wave. Method: The presented algorithm uses the first derivative linked to mobile conditionals to eliminate unwanted points, as well as unreliable intervals. The algorithm was evaluated using the annotation of an expert, with 5 records of arterial pulse wave of 5 minutes (5236 annotations) and contaminated at different signal-to-noise ratios (15, 12 and 9 dB). Results: When compared with the annotations of an expert, the algorithm detected these fiducial points with an average sensitivity, positive predictivity and 100 percent accuracy and showed errors of less than 10ms. In arterial pulse wave signals contaminated with noise in both cases the relative error was less than 2 percent with respect to a sampling period of 800ms. Conclusions: the algorithm provides a simple but accurate detection of the clinical points of interest of the arterial pulse wave, robust to noise and movement artifacts that could be used in the evaluation of the stiffness index and vascular reflection(AU)

Prueba de elevación de piernas pasiva / The passive leg raising test (PLR)

Introduction: The passive leg raising test (PLR) allows physicians to determine which patients require treatment with intravenous fluids. Objectives: It is important to be aware of tools that help us to determine the response to the passive leg raising test, as well as understanding in which clinical situations it can be performed. Materials and methods: Non-systematic review. Medline and PubMed databases were consulted in search of relevant articles. Results: Through echocardiography, pulse pressure and capnography can be determined as a response to leg raising. Conclusions: This article explores the tools that are useful in determining the response to this maneuver, and the clinical conditions in which it is indicated.

Introducción: la prueba de elevación de piernas pasivas permite determinar en qué paciente se requiere manejo con líquidos endovenosos. Objetivos: es importante conocer las herramientas que ayudan a determinar la respuesta a la prueba de elevación de piernas pasiva, además conocer en qué situaciones clínicas se puede realizar. Materiales y métodos: revisión no sistemática. Se consultaron las siguientes bases de datos Medline y Pubmed, en búsqueda de artículos relevantes. Resultados: mediante ecocardiografía, presión de pulso y capnografía se puede determinar la respuesta a la elevación de piernas. Conclusiones: el presente artículo explora las herramientas que son útiles para determinar la respuesta a esta maniobra y las condiciones clínicas donde se indica.

Velocidade da onda de pulso, pressão arterial e adipocitocinas em adultos jovens: estudo do Rio de Janeiro / Pulse wave velocity, blood pressure and adipocytokines in young adults: the Rio de Janeiro study

FUNDAMENTO: Dados sobre a avaliação não invasiva vascular e suas relações com variáveis de risco cardiovascular são escassos em jovens. OBJETIVO: Avaliar a relação entre a velocidade de onda de pulso e a pressão arterial,variáveis antropométricas e metabólicas, incluindo as adipocitocinas, em indivíduos adultos jovens. MÉTODOS: Foram avaliados 96 indivíduos (51 homens) do estudo do Rio de Janeiro, de 26 a 35 anos (média 30,09 ± 1,92). Foram obtidos a velocidade de onda de pulso (método Complior), pressão arterial, índice de massa corporal, glicose, perfil lipídico, leptina, insulina, adiponectina e o índice de resistência à insulina HOMA-IR. Os indivíduos foram estratificados em três grupos segundo o tercil da VOP para cada sexo. RESULTADOS: O grupo com maior tercil de VOP mostrou maiores médias de pressão arterial sistólica, pressão arterial diastólica, pressão arterial média, índice de massa corporal, insulina, HOMA-IR e menores médias de adiponectina, além de maiores prevalências de diabetes mellitus/intolerância à glicose e hiperinsulinemia. Houve correlação significativa e positiva da velocidade da onda de pulso com pressão arterial sistólica, pressão arterial diastólica, pressão de pulso e pressão arterial média, índice de massa corporal, e LDL-colesterol e negativa com HDL-colesterol e adiponectina. Em modelo de regressão múltipla, após ajuste do HDL-colesterol, LDL-colesterol e adiponectina para sexo, idade, índice de massa corporal e pressão arterial média, apenas o sexo masculino e a pressão arterial média mantiveram correlação significativa com a velocidade de onda de pulso. CONCLUSÃO: A velocidade de onda de pulso em adultos jovens mostrou relação significativa com variáveis de risco cardiovascular, destacando-se o sexo masculino e a pressão arterial média como importantes variáveis no seu determinismo. Os achados sugerem que a medida da VOP pode ser útil para a identificação do acometimento vascular nessa faixa etária.

BACKGROUND: Data on noninvasive vascular assessment and their association with cardiovascular risk variables are scarce in young individuals. OBJECTIVE: To evaluate the association between pulse wave velocity and blood pressure, anthropometric and metabolic variables, including adipocytokines, in young adults. METHODS: A total of 96 individuals aged 26 to 35 years (mean 30.09 ± 1.92; 51 males) were assessed in the Rio de Janeiro study. Pulse wave velocity (Complior method), blood pressure, body mass index, glucose, lipid profile, leptin, insulin, adiponectin and insulin resistance index (HOMA-IR) were analyzed. Subjects were stratified into three groups according to the PWV tertile for each gender. RESULTS: The group with the highest pulse wave velocity (PWV) tertile showed higher mean systolic and diastolic blood pressure, mean blood pressure, body mass index, insulin, and HOMA-IR, as well as lower mean adiponectin; higher prevalence of diabetes mellitus/glucose intolerance and hyperinsulinemia. There was a significant positive correlation of PWV with systolic blood pressure, diastolic blood pressure, pulse pressure and mean blood pressure, body mass index, and LDL-cholesterol, and a negative correlation with HDL-cholesterol and adiponectin. In the multiple regression model, after adjustment of HDL-cholesterol, LDL-cholesterol and adiponectin for gender, age, body mass index and mean blood pressure, only the male gender and mean blood pressure remained significantly correlated with PWV. CONCLUSION: PWV in young adults showed a significant association with cardiovascular risk variables, especially in the male gender, and mean blood pressure as important determinant variables. The findings suggest that PWV measurement can be useful for the identification of vascular impairment in this age group.

Avaliação da patência da artéria radial após cateterismo transradial / Evaluation of radial artery patency after transradial catheterization

INTRODUÇÃO: Embora a abordagem transradial tenha reduzido as complicações vasculares, a oclusão da artéria radial ainda é uma de suas limitações. O objetivo deste estudo foi avaliar a patência da artéria radial após cateterismo cardíaco transradial. MÉTODOS: Estudo de coorte prospectivo com pacientes submetidos a cateterismo cardíaco pela via transradial. Os procedimentos foram realizados com cateteres 5 F ou 6 F, com a administração de 5.000 U de heparina e 200 µg de nitroglicerina através do introdutor radial. O fluxo sanguíneo na artéria radial foi avaliado com o uso do Doppler antes, imediatamente após a retirada do curativo e 7 dias depois do procedimento. RESULTADOS: O estudo incluiu 120 pacientes, dos quais 42,5% eram do sexo masculino, com idade de 59,1 ± 10,6 anos, 25,8% eram diabéticos, com peso de 77,4 ± 14,2 kg e altura de 166 ± 8,1 cm. O número de cateteres utilizados foi de 2,3 ± 0,5 por paciente, 55,8% usando introdutores 6 F. A duração do procedimento foi de 14,8 ± 5,2 minutos, o tempo de punção foi de 129,7 ± 124,1 segundos e o tempo de fluoroscopia, de 4 ± 2,3 minutos. Espasmo e crossover para técnica femoral ocorreram em 20,8% e 1,7% dos procedimentos, respectivamente. Hematoma significativo ocorreu em 2,4% dos pacientes. Em uma semana de acompanhamento, observaram-se oclusões da artéria em 1,7% e redução do fluxo sanguíneo em 26,7% dos pacientes. CONCLUSÕES: A oclusão da artéria radial pós-procedimento diagnóstico utilizando a via de acesso radial é infrequente e não deve ser considerada limitação importante da técnica.

BACKGROUND: Although the transradial approach has reduced vascular complications, radial artery occlusion is still considered one of its limitations. The aim of this study was to evaluate radial artery patency after transradial cardiac catheterization. METHODS: Prospective cohort study of patients undergoing cardiac catheterization using the transradial approach. Procedures were performed with 5 F and 6 F catheters with the administration of 5,000 IU of heparin and 200 µg of nitroglycerin through the radial sheath. Radial artery blood flow was assessed by Doppler before, immediately after bandage removal and 7 days after the procedure. RESULTS: The study included 120 patients of which 42.5% were males, with 59.1 ± 10.6 years of age, 25.8% were diabetic, weighing 77.4 ± 14.2 kg and height of 166 ± 8.1 cm. The number of catheters used was 2.3 ± 0.5 per patient, 55.8% using 6 F sheaths. Duration of the procedure was 14.8 ± 5.2 minutes, puncture time was 129.7 ± 124.1 seconds and fluoroscopy time was 4 ± 2.3 minutes. Radial spasm and crossover to the femoral technique occurred in 20.8% and 1.7% of the procedures, respectively. Significant hematoma was observed in 2.4% of the patients. At 1 week of follow-up, arterial occlusion was observed in 1.7% and reduced blood flow in 26.7% of the patients. CONCLUSIONS: Radial artery occlusion following diagnostic procedure using the transradial approach is rare and should not be considered as an important technique limitation.

Nuevos modelos conceptual y matemático para el contorno de la onda de volumen de pulso arterial / New conceptual and mathematical forms for the contour of volume wave of arterial pulse

Introducción: El análisis del contorno de la onda de volumen de pulso arterial ha sido útil para el diagnóstico no invasivo de enfermedades cardiovasculares, pero los orígenes patofisiológicos que contribuyen a este contorno no están totalmente explicados. El objetivo de este trabajo fue hallar el nivel de coincidencia de un nuevo modelo conceptual simple, basado en las fuerzas hemodinámicas, con respecto a un nuevo modelo matemático aplicado a las diferentes clases de ondas de volumen de pulso arterial en dedos de miembros inferiores. Métodos: la propuesta del modelo conceptual se basó en que este contorno es la suma de pares de gradientes de fuerzas hemodinámicas de acción, provenientes del corazón, la aorta y el distrito arterial periférico, y las de reacción, provenientes de la pared arterial músculo-elástica bajo estudio. El modelo matemático fue diseñado como un problema de programación no lineal, para hallar las 6 incógnitas numéricas de cada par de gradientes, bajo restricciones no lineales basadas en sus relaciones temporales. Se registraron los contornos desde los dedos de miembros inferiores, en pacientes en los que se pudieran observar las 4 clases de contornos de onda de volumen de pulso arterial conocidos. Se analizó la calidad de ajuste de 4 403 contornos de onda de volumen de pulso arterial experimentales, contra su onda de volumen de pulso arterial resultante del modelo matemático, desde 123 registros de 14 pacientes (7 mujeres). Resultados: La clase III fue la predominante, las clases I y II fueron frecuentes en pacientes con menos riesgo cardiovascular y la clase IV, en los de mayor riesgo...

Introduction: The analysis of volume wave contour of arterial pulse has been useful for non-invasive diagnosis of cardiovascular diseases, but the pathophysiological origins contributing to this contour are not totally explained. The objective of present paper was to find the coincidence level of a new simple conceptual form, based on the hemodynamic strengths regarding a new mathematical form applied to different classes of volume waves of arterial pulse in toe fingers. Methods: The proposal of conceptual form was based on that this contour is the addition of pairs of action hemodynamic strengths gradients from the heart, aorta and the peripheral arterial zone and of the reactions coming from study musculoelastic arterial wall. The mathematical form was designed as a non-lineal programming problem to find the six numeral unknown quantities of each pair of gradients, under non-lineal restriction based on its temporary relations. The contours from toe fingers were registered in patients with four potential classes of volume wave known contours of arterial pulse. The fitting quality of 4 403 experimental above mentioned contours was analyzed versus the arterial pulse volume resulting from mathematical form of 123 registries of 14 patients (7 women). Results: There was predominance of III class, the I and II ones were frequent in patients with less cardiovascular risk and the IV class in those of great risk. The 64 percent of the wave volume of arterial pulse had a quality fitting > 95 percent and the 36 percent had the presence of oscillating waves from skeletal muscle. Conclusions: The coincidence of both forms is accepted to characterize in a morphologic way the contour of any class of wave volume of arterial pulse

Avaliação da velocidade de onda de pulso aórtico em mulheres com gestação complicada por Diabetes Mellitus Gestacional / Assessment of aortic stiffness in women with gestational diabetes

Introdução: O diabetes mellitus gestacional (DMG) é uma complicação freqüente da gravidez que pode preceder o surgimento de diabetes mellitus tipo 2 (DM2) e estar relacionado com um risco aumentado de doença cardiovascular (DCV). A medida não-invasiva da velocidade de onda de pulso (VOP) é considerada como a melhor forma de investigar alterações da complacência arterial, um marcador pré-clínico de risco cardiovascular. Entretanto, a relação entre o DMG e o comportamento da VOP não está bem elucidada sendo apenas recentemente descrita. O objetivo deste estudo foi avaliar comparativamente a VOP em gestantes com DMG confirmado por teste oral de tolerância à glicose com 100g (TOTG), com um grupo pareado composto por gestantes consideradas saudáveis. Metodologia: Neste estudo casocontrole transversal, foram incluídas 24 gestantes com DMG e 27 gestantes de um grupo controle pareado. Foi considerado critério de exclusão do estudo a presença de passado de exposição a qualquer grau de intolerância à glicose. Todas gestantes foram avaliadas quanto a dados clínicos, demográficos e laboratoriais, além das medidas de VOP em territórios carótida-radial e carótida-femoral. As medidas de VOP foram realizadas por técnica de tonometria por aplanação com aparelho marca Complior®. Resultados: Os grupos apresentaram valores semelhantes de idade cronológica, idade gestacional, IMC e pressãoarterial (PA). Gestantes com DMG apresentaram valores de VOP em territórios periférico e aórtico equiparáveis aos observados no grupo controle: 8,3±0,8 vs. 8,5±1,0 m/s (p=0.40) e 7,2±0,9 vs. 7,3±1,2 m/s (p=0.79) respectivamente. Quando categorizadas em relação à mediana da VOP aórtica (7,3m/s), idade (p<0.001), PA diastólica (p=0.03) e freqüência cardíaca (p=0.02) se relacionaram com o aumento da VOP. Gestantes do grupo alvo com medidas da VOP aórtica acima da mediana apresentaram tendência a terem valores mais altos de glicemia 1 hora pós prandial (128,2±24.2 mg/dL vs 118,0±14.6 mg/dL, p=0,22) e controle glicêmico insatisfatório (p=0,09). Os valores da área sob a curva do TOTG foram semelhantes dentre as gestantes do grupo alvo não tendo relação com os valores de VOP. Conclusão: Apesar da hipótese de que o DMG pode ser fator de risco para DCV, gestantes com DMG não apresentam valores maiores de VOP em comparação a gestantes saudáveis. O período de exposição à hiperglicemia pode ter sido insuficiente para aumentar a rigidez arterial em gestantes com DMG.

Background: Gestational diabetes mellitus (GDM) may precede type 2 diabetes (T2DM) development and may be related to cardiovascular disease (CVD). Pulse wave velocity (PWV) measurement is the gold-standard non-invasive method to evaluate arterial stiffness, a preclinical cardiovascular risk marker. However, the relationship between PWV and GDM is not clear, and has only recently been investigated. The aim of this study was to evaluate aortic PWV in women with confirmed GDM through 100g oral glucose tolerance test (OGTT) in comparison to a matched control group of healthy pregnant women. Methods: This sectional case-control study included 24 women with GDM and 27 matched controls. Exclusion criteria included previous glucose impairment of any degree. Clinical, demographic and laboratory variables were obtained. Carotid-radial (peripheral) and carotid-femoral (aortic) PWV were measured by applanation tonometry with Complior® equipment. Results: Both groups had similar age, gestational age, body mass index, ethnicity, smoking status, and blood pressures (BP). Women with GDM had comparable peripheral and aortic PWV to controls: 8.3±0.8 vs. 8.5±1.0 m/s (p=0.40) and 7.2±0.9 vs. 7.3±1.2 m/s (p=0.79) respectively. When categorized according to the median value of aortic PWV (7.3m/s), age (p<0.001), diastolic BP (p=0.03) and heart rate (p=0.02) were associated with increased arterial stiffness. GDM women with PWV values above the median presented a trend towards higher 1-hour post-prandial glycemia (128.2±24.2 mg/dL vs. 118.0±14.6 mg/dL, p=0.22) and worse glycemic control (p=0.09). Also in the GDM group, the diagnostic OGTT area under the curve was similar in women with higher or lowers aortic PWV. Conclusion: Although GDM may be a risk factor for CVD development, women with GDM do not have higher peripheral or central arterial stiffness than healthy pregnant women. Time of exposure to hyperglycemia may have been insufficient to increase arterial stiffness in GDM women.

Relación del síndrome metabólico y sus componentes con la presión del pulso en personas sin enfermedad aparente / Correlation between Metabolic Syndrome and Its Components with Pulse Pressure in Persons without Apparent Disease

Introducción La presión del pulso depende en gran medida de la rigidez arterial. Varios estudios se han centrado en el hecho de que diversos factores, entre ellos el síndrome metabólico o sus componentes, intermedian cambios que afectan en forma adversa las propiedades elásticas de las grandes arterias, acentuando su rigidez. Objetivo El propósito de este trabajo de investigación fue evaluar la influencia del síndrome metabólico y sus componentes sobre la presión del pulso en personas sin enfermedad aparente. Material y métodos Se seleccionaron al azar 1.155 individuos sin enfermedad demostrable. Se registraron las variables que definen el síndrome metabólico (ATP III): en mg/dl y en ayunas, colesterol HDL ≤ 40/50 (hombres/mujeres), triglicéridos ≥ 150, glucemia ≥ 100, perímetro de la cintura (cm) ≥ 102/88 (hombres/mujeres) y presión arterial sistólica/diastólica ≥ 130/85 mm Hg. Se compararon los valores de la presión del pulso obtenidos al agrupar a los participantes por sexo y edad. Se estableció la frecuencia de los factores que definen el síndrome metabólico y mediante regresión lineal se ajustó la presión del pulso por sexo, edad y por el conjunto de ellos. A continuación se determinó el valor ajustado de la presión del pulso correspondiente a cada factor del síndrome metabólico y se comparó con el de sujetos normales. Finalmente, se calculó la presión del pulso ajustada de acuerdo con las posibles combinaciones de tres o más factores (criterio diagnóstico de síndrome metabólico) y se comparó con la de individuos en los que no se hallaba presente ningún componente del síndrome. Resultados Características generales de los 1.155 individuos: hombres 62%, edad 38 ± 9 años (rango 20-66), perímetro de la cintura 89 ± 13 cm, triglicéridos 107 ± 74 mg/dl, glucemia 82 ± 16 mg/dl, colesterol HDL 48 ± 13 mg/dl, presión arterial sistólica 124 ± 14 mm Hg, diastólica 78 ± 9 mm Hg, presión del pulso 46 ± 9 mm Hg. Edad: 38 ± 9 años los hombres (n = 712) y 37 ± 9 años las mujeres (n = 443); p = ns. La presión del pulso fue de 48 ± 8 mm Hg en los hombres versus 43 ± 9 mm Hg en las mujeres; p < 0,001. Efecto de la edad sobre la presión del pulso: 45 ± 8 en individuos < 35 años versus 47 ± 9 en ≥ 35 años; p <0,001. Frecuencia de los distintos elementos que definen el síndrome metabólico: perímetro de la cintura ≥ 102/88 cm: 18%, glucemia ≥ 100 mg/dl: 7%, triglicéridos ≥ 150 mg/dl: 17%, colesterol HDL ≤ 40/50 mg/dl: 45%, presión arterial sistólica≥ 130 mm Hg: 40%, diastólica ≥ 85 mm Hg: 16%. Al comparar la presión del pulso ajustada delimitada por cada factor del síndrome metabólico con la de los controles se obtuvo: perímetro de la cintura ≥ 102/88 cm: 48 ± 4 versus 46 ± 3, glucemia ≥ 100 mg/dl: 52 ± 5 versus 46 ± 3, triglicéridos ≥ 150 mg/dl: 48 ± 3 versus 46 ± 4, colesterol HDL ≤ 40/50 mg/dl: 44± 3 versus 47 ± 3; presión arterial sistólica ≥ 130 mm Hg: 48 ± 4 versus 45 ± 3; diastólica ≥ 85 mm Hg: 48 ± 5 versus 46 ± 3, todas p < 0,001. Por último, se comprobó la presión del pulso ajustada de acuerdo con las posibles combinaciones de tres o más factores y se comparó con la de individuos en los que no se hallaba presente ningún componente del síndrome metabólico; el resultado fue 49 ± 5 versus 46 ± 3, p < 0,001. Conclusiones El síndrome metabólico y/o sus componentes individuales inducen una elevación de la presión del pulso, a excepción del colesterol HDL. Este efecto parece ser independiente de la edad, del sexo y de la eventual interacción entre las variables analizadas.

Background Pulse pressure depends mostly on arterial wall stiffness. Several studies have focused on the fact that many factors, including the metabolic syndrome or its components, interact to impact on great vessels elastic properties, increasing arterial wall stiffness. Objective To evaluate the influence of the metabolic syndrome and its components on pulse pressure in persons without any apparent disease. Material and Methods A total of 1.155 subjects without demonstrable disease were randomly selected. The metabolic variables defining metabolic syndrome (ATP III) were recorded: fasting HDL-cholesterol ≤40/50 mg/dl (men/women), fasting triglycerides≥150 mg/dl, fasting glycemia ≥100 mg/dl, waist circumference ≥102/88 cm (men/women) and systolic/diastolic blood pressure ≥130/85 mm Hg. Patients' pulse pressure values were compared among different groups according to gender and age. The frequency of the metabolic syndrome components was determined and pulse pressure was adjusted by gender, age and all the components using multiple linear regression analysis. The adjusted value of pulse pressure corresponding to each metabolic syndrome component was determined and compared to that of normal subjects. Finally, adjusted pulse pressure was calculated according to the possible combinations of three factors or greater (diagnostic criteria of metabolic syndrome) and was compared with that of individuals without any component of the metabolic syndrome. Results General characteristics of the 1.155 individuals: men 62%, age 38±9 years (range 20-66), waist circumference 89±13 cm, triglycerides 107±74 mg/dl, glycemia 82±16 mg/dl, HDL-cholesterol 48±13 mg/dl, systolic blood pressure 124±14 mm Hg, diastolic blood pressure 78±9 mm Hg, pulse pressure 46±9 mm Hg. Age: 38±9 years in men (n=712) and 37±9 years in women (n=443); p=ns. Pulse pressure was 48±8 mm Hg in men versus 43±9 mm Hg in women; p<0.001. Influence of age on pulse pressure: 45±8 in individuals <35 years versus 47±9 in ≥35 years; p<0.001. Frequency of metabolic syn- drome components: waist circumference ≥102/88 cm: 18%, glycemia ≥100 mg/dl: 7%, triglycerides ≥150 mg/dl: 17%, HDL-cholesterol ≤40/50 mg/dl: 45%, systolic blood pressure≥130 mm Hg: 40%, diastolic blood pressure ≥85 mm Hg: 16%. When pulse pressure adjusted by each component of the metabolic syndrome was compared to that of controls, the following values were obtained: waist circumference≥102/88 cm: 48±4 versus 46±3, glycemia ≥100 mg/dl: 52±5 versus 46±3, triglycerides ≥150 mg/dl: 48±3 versus 46±4, HDL-cholesterol ≤40/50 mg/dl: 44±3 versus 47±3; systolic blood pressure ≥130 mm Hg: 48±4 versus 45±3; diastolic blood pressure ≥85 mm Hg: 48±5 versus 46±3, all p<0.001. Finally, adjusted pulse pressure according to the possible combinations of three factors or greater was calculated and compared with that of individuals without any component of the metabolic syndrome: 49±5 versus 46±3, p<0,001. Conclusions The metabolic syndrome and/or its components induce pulse pressure elevation, except for HDL-cholesterol. This effect seems to be independent of age, gender and the eventual interaction of the variables analyzed.

Índice para la evaluación de las reflexiones mediante análisis de la onda de pulso radial / Index of Pressure Wave Reflection Assessed from Radial Pulse Wave Analysis

En el presente trabajo se analiza la posibilidad de utilizar un parámetro obtenido del registro de la onda de pulso radial, el ancho de la onda sistólica, que es más sencillo de medir aún que el índice de aumentación radial y que complementaría a este último en la evaluación de la amplitud de la reflexión sistólica, directamente relacionada con el grado de disfunción endotelial y el fenómeno de aumentación aórtica. Se efectuó un estudio poblacional sobre 120 varones normotensos sanos con edades entre 17 y 65 años. Se obtuvo en ellos el registro de la onda de pulso radial en base al registro del movimiento de las paredes de la arteria mediante un sensor capacitivo aplicado sobre la zona de palpación del pulso. Cada registro se procesó y normalizó en amplitud y se calculó el índice de aumentación radial y el ancho de la onda sistólica al 50% de su altura máxima. Se halló que individuos con el mismo índice de aumentación poseían distintos valores de ancho de onda sistólica, lo cual evidencia distintos valores de amplitud de la onda reflejada. Ambos parámetros aumentaron con la edad y su correlación r resultó de 0,9. Se propone la utilización del ancho de la onda sistólica como un índice de envejecimiento alternativo, que permitiría evaluar el sistema arterial cuando la medición del índice de aumentación resultara dificultosa o la comparación entre individuos fuera ambigua.

Systolic wave width, a parameter obtained from the record of radial pulse wave, is easier to measure than the augmentation index. The aim of this study was to analyze the possibility of using systolic wave width as a complementary tool for the assessment of systolic wave reflection which is directly related to the degree of endothelial dysfunction and to aortic augmentation. We performed a population study on 120 healthy men between 17 and 65 years old with normal blood pressure. Records of the radial wave pulse were obtained, based on the movement of the arterial walls, by a capacitive sensor in contact with the surface of the wrist over the radial artery. Each record was processed and its amplitude was normalized; the augmentation index and systolic wave width at half its maximum height were calculated. We found that systolic wave width was different among subjects with the same augmentation index, showing different values of the amplitude of the reflected wave. Both parameters increased with age (r correlation value 0.9). The systolic wave width is an alternative index of ageing. It might assess the arterial system when it is difficult to measure augmentation index or when comparisons between individuals result ambiguous.

Análise espectral do pulso arterial durante a circulaçäo extracorpórea: estudo experimental em cäes / Spectral analysis of the arterial pulse during cardiopulmonary bypass: experimental study in dogs

Objetivo: Avaliar o modelo do pulso arterial através da análise espectral que melhor reproduza as condições circulatórias fisiológicas durante a circulação extracorpórea com fluxo pulsátil e laminar. Material e Métodos: Dez cães adultos submetidos à circulação extracorpórea com bomba de roletes e de fluxo pulsátil instaladas em paralelo. O fluxo da circulação extracorpórea foi ajustado ao pré-existente que foi medido com fluxômetro Statham 2200. As curvas de pressão tanto com bomba de fluxo laminar, quanto com bomba de fluxo pulsátil foram registradas em fita magnética HP Recorder e analisados pelo método Fast Fourier Transform (algoritmo CooleyTukeyl. Variou-se o período da bomba pulsátil em relação ao ciclo total de 70, 60, 50, 40 e 30%. Resultados: O traçado do pulso arterial durante o uso da bomba de roletes mostrou um onda bífida com depressão profunda seguida por outra de pico único. Foram observados, espectralmente, três componentes de mesma amplitude. O uso de bomba pulsátil proporcionou, à análise espectral, componentes harmônicos de amplitudes inversamente proporcionais à relação ejeção/ciclo...

Purpose: Spectral analysis of arterial pulse was performed during cardiopulmonary bypass with both pulsatile and continuous flow in order to evaluate the pulse model best suitable to reproduce physiological circulatory conditions. Material and Methods: Ten adult mongrel dogs were submitted to cardiopulmonary bypass with a roller pump for continuous flow and pulsatile flow pump in paralel. The physiological pressure waves, the roller pump waves and the pulsatile pump flow waves were recorded. During the pulsatil flow we varied the ejective period of the pump in relation to the total cycle by 70%, 60%, 50%, 40% and 30%. Results: The roller pump flow showed a bifid wave followed by single peak wave. During spectral analysis we observed three harmonic components of the same amplitude. The using of the pulsatile pump flow proportionated, by spectral analysis, harmonic components whose amplitudes are inversely proportional for ejection/cycle ratio...