RESUMEN
The goal of the present study was to develop and evaluate algorithms for non-invasive, real-time, beat-to-beat monitoring of stroke index (SI), blood pressure (BP) and total peripheral resistance index (TPRI) which has a menu-driven interface, suitable for routine use by unskilled staff. In addition, it was our aim to include a meta-analysis for the evaluation of autonomic function derived from the above haemodynamic data. This includes spectral analysis of heart rate (HR), BP, SI and TPRI and the automatic calculation of baroreceptor reflex sensitivity. Impedance cardiography was used for beat-to-beat SI determination, Finapres corrected by an oscillometric blood pressure measurement (Dinamap) on the upper arm for beat-to-beat BP measurement. We demonstrate noise free recordings during physiological (head up tilt) and pharmacological intervention (alpha 1-, beta 2-adrenoreceptor agonists, insulin induced hypoglycemia). The newly developed software should prove valuable for physiological, pharmacological and clinical studies.
Asunto(s)
Sistema Nervioso Autónomo/fisiopatología , Electrocardiografía/instrumentación , Hemodinámica/fisiología , Monitoreo Fisiológico/instrumentación , Procesamiento de Señales Asistido por Computador/instrumentación , Programas Informáticos , Adulto , Albuterol , Enfermedades del Sistema Nervioso Autónomo/diagnóstico , Enfermedades del Sistema Nervioso Autónomo/fisiopatología , Presión Sanguínea/fisiología , Monitores de Presión Sanguínea , Cardiografía de Impedancia/instrumentación , Sistemas de Computación , Femenino , Humanos , Insulina , Masculino , Metoxamina , Persona de Mediana Edad , Presorreceptores/fisiopatología , Valores de Referencia , Reflejo/fisiología , Volumen Sistólico/fisiología , Resistencia Vascular/fisiologíaRESUMEN
Neck pain after whiplash injury of the cervical spine often induces typical changes in head motion patterns (amplitude, velocity). These changes of kinematics may help to recognize malingerers. We investigated the hypothesis that malingerers are not able to reproduce their simulated head movement disturbances three times. The kinematics of head movements of 23 patients with neck pain after whiplash injury and of 22 healthy subjects trying to act as malingerers were compared. The healthy subjects were informed about the symptomatology of whiplash injury and were asked to simulate painful head movements. Two different kinds of head movements were registered and analyzed by Cervicomotography: (1) the slow free axial head rotation (yaw) and (2) the axial head rotation (yaw) tracking a moving visual target. Each experimental condition was presented three times, expecting the malingerers not to be able to produce as well as to reproduce the same head movement disturbances again and again. In patients, as a consequence of their distinct pain patterns, we expected less variance between the test repetitions. The statistical analysis showed significant differences of the calculated kinematic parameters between both groups and the inability of healthy subjects to simulate and to reproduce convincingly distinct pain patterns.
RESUMEN
An epidemiological study is presented to demonstrate, in addition to the viral aetiology, the influence of airpollution and various weather conditions to the incidence of croup. By means of a special statistic tool (baseline data curves) we could demonstrate that rapid changes in airpollutants (especially NO and NO2) are followed by increased occurrence of croup. In addition, the quotient NO2/NO seems to correlate directly to the O3 concentration. The noticeable influence of airpollution as well as changing climatic conditions demonstrate the multiform aetiology of croup.
Asunto(s)
Contaminantes Atmosféricos/efectos adversos , Clima , Crup/inducido químicamente , Preescolar , Crup/etiología , Métodos Epidemiológicos , Humanos , Lactante , Óxido Nítrico/efectos adversos , Óxidos de Nitrógeno/efectos adversos , Ozono/efectos adversosRESUMEN
We have studied sodium potassium ATPase activity, the effect of endogenous plasma on sodium pump activity, potassium permeability and intracellular sodium and potassium concentrations in normotensive subjects without (n = 36) and with (n = 33) a positive family history of hypertension, and in patients with untreated essential hypertension (n = 52). Sodium pump activity was studied as ouabain sensitive uptake of rubidium 86 in washed red blood cells, incubated in an artificial medium closely resembling the anorganic constituents of plasma. Any influence of endogenous plasma on sodium pump activity was investigated by re-incubating the washed red blood cells in their own plasma and comparing ouabain sensitive rubidium uptake in the two media. To correct for any possible differences in external potassium concentration, a function for the relation between extracellular potassium concentration and absolute transport rates was derived experimentally. From this, actual transport rates in plasma were corrected by computer to an extracellular potassium concentration of 4.0 mmol/l. Sodium pump activity, concentration of circulating sodium transport inhibitor, potassium permeability and intracellular electrolytes were not statistically different in subjects with and without a positive family history of hypertension. Hypertensives had significantly raised sodium pump activity in artificial medium, but not when red cells were re-incubated in their own plasma. Thus, endogenous plasma inhibited the sodium pump by between 12% and 15%. Hypertensives also had a significantly raised potassium permeability. Potassium permeability and sodium pump activity were correlated significantly. Intracellular sodium concentrations were similar in normotensives and hypertensives, but the later showed a significantly lower intracellular potassium concentration.(ABSTRACT TRUNCATED AT 250 WORDS)