Características clínicas y polisomnográficas de pacientes con apnea central. ¿Se benefician de servoventilación adaptativa? / No disponible

Objetivo: Describir las características clínicas y polisomnográficas de los pacientes en tratamiento con servoventilación adaptativa (ASV) en nuestro centro. Métodos: Estudio retrospectivo en el que se incluyen 26 pacientes que requirieron tratamiento con ASV para alcanzar un adecuado control clínico y polisomnográfico de los eventos respiratorios. Los pacientes acudieron a la Unidad Multidisciplinar de Sueño de la Fundación Jiménez Díaz entre mayo de 2009 y noviembre de 2011. Todos los pacientes iniciaron tratamiento con CPAP, y posteriormente fueron evaluados y revisados en la consulta de trastornos respiratorios del sueño. Tras un periodo de tres meses con dicho tratamiento, se realizó una titulación manual con polisomnografía (PSG). El tratamiento se cambiaba a ASV si se objetivaba escaso control clínico o polisomnográfico o si aparecía síndrome de apneas complejas (CompSAS). Resultados: De los 26 pacientes incluidos en el estudio, 15 pacientes presentaban un síndrome de apnea central (CSA) en su primer estudio polisomnográfico, mientras que los otros 11 pacientes presentaban un síndrome de apnea obstructiva severa. Tras el tratamiento inicial, este segundo grupo desarrolló compSAS. Todos los pacientes incluidos fueron varones, con una edad media de 61 años y una media de 67 eventos respiratorios por hora (IAH). La nicturia, la fragmentación en el sueño, el cansancio y el insomnio fueron los síntomas clínicos referidos con mayor frecuencia. La somnolencia fue evaluada con la escala de Epworth con un valor medio de 13 puntos antes del tratamiento. El tratamiento con CPAP se realizó con una presión media de 8 cm de H2O. Tras cumplir tres meses con el tratamiento, se realizaba una titulación manual con PSG que mostró un IAH medio de 40. Ante estos hallazgos estos pacientes fueron cambiados a servoventilación. Una segunda titulación manual de PSG mostró un IAH final de 11. Aquellos pacientes con somnolencia residual refirieron también una mejora cínica con el servoventilador. Conclusiones: La servoventilación adaptativa es una herramienta terapéutica eficaz en pacientes con CSA y compSAS para el control de eventos respiratorios y sus síntomas. La titulación manual con PSG es necesaria para asegurar el correcto diagnóstico de compSAS y como parte del seguimiento de estos pacientes (AU)

AIMS of the study: To describe clinical characteristics and polysomnographic parameters of patients treated with adaptative servoventilation (ASV) in our centre. Methods: Retrospective and descriptive study of 26 patients who required ASV to obtain a clinical and polisomnographic control of respiratory events. The patients were admitted in our Multidisciplinary Sleep Unit (MDSU) at Fundación Jiménez Díaz from may 2009 to november 2011. Continuous positive airway pressure (CPAP) treatment was the initial treatment for all patients; they were followed in our outpatient sleep-disorders consults. After three months with CPAP, we conducted a manual titration PSG. The treatment was switched to ASV if there was poor clinical or polisomnographic control or if complex sleep apnea (CompSAS) appeared. Results: 15 out of the 26 patients who were treated with ASV presented Central sleep apnea (CSA) on their first PSG study, while the remaining 11 patients were diagnosed as having severe obstructive sleep apnea. After the initial treatment with CPAP, the later group developed compSAS. All patients were male, with an average age of 61 years and a mean AHI of 67 events per hour. Nocturnal sleep fragmentation, tiredness and insomnia were the most frequent clinical symptoms. Sleepiness was evaluated with the Epworth scale with a mean value previous to treatment of 13. The initial treatment with CPAP had a medium pressure of 8 cm H2O. After three months on this treatment a manual titration PSG showed a mean AHI of 40. Thus, all the patients were switched to servoventilation. A second manual titration PSG showed a mean AHI of 11. Those patients with residual somnolence reported clinical improvement under treatment with ASV. Conclusions: ASV is an effective therapeutic tool for CSA and CPAP refractory/resistant compSAS, for controlling both apneic events and symptoms. A manual titration PSG is necessary for a correct diagnosis of compSAS and as part of the follow up of these patients (AU)

Evaluation of COPD Longitudinally to Identify Predictive Surrogate End-points (ECLIPSE)

No disponible

No disponible

Estimating pesticide exposure in tidal streams of Leadenwah Creek, South Carolina.

This article estimates the potential exposure of estuarine organisms to two pesticides (azinphosmethyl and fenvalerate) in a tidal stream of Leadenwah Creek near the Edisto River, South Carolina, during four runoff episodes. Exposure is calculated from simulation runs of the one-dimensional transport equation solved by an implicit finite difference method. Calibration was done for each episode by adjusting three conditions (runoff starting time, duration, and flow) and a correction to the dispersion coefficient in order to match the continuously measured salinity transients. First-order rate constants used by the fate component were calculated from half-life values reported in the literature. Baseline scenarios for each episode and each pesticide were derived by using the same conditions obtained in the salinity runs and adjusting the pesticide loading in order to mimic the few data points of measured pesticide concentrations. In all baseline scenarios, pesticide concentration rises following the initial burst of runoff (also noticeable as an abrupt drop in salinity) and then oscillates, forced by the tidal cycle. These oscillations are dominated by transport, while fate imposes a secular decaying trend. Ten additional scenarios for each episode were obtained from the baseline scenario by randomly varying three pesticide load parameters (starting time and duration of runoff, and pesticide discharge) using a Latin hypercubes design. Two exposure metrics were calculated from the simulated and the measured pesticide concentration: maximum and time average, which was obtained by integrating the curve and dividing by the time period. The metrics calculated from the baseline runs are relatively close to the data-derived metrics, because the baseline runs attempted to mimic the data. For each one of the two metrics and all pesticide-episode combinations, several statistics of the set of 11 scenarios were also calculated: minimum and maximum, mid-range, mean, standard deviation, and median. The mean +/- standard deviation interval of the simulation-derived value consistently brackets the data-derived value for the maximum metric, but not for the time-average metric. This may indicate that even if the maximum value is correctly captured in the field sample, the time-average exposure could be in error when calculated directly from the field data due to undersampling of the pesticide time series. The methodology developed here attempts to reconstruct the possible exposure from the sparse sampling of the pesticide concentration during the runoff episodes; only when the number of field samples is high and regularly spaced is it possible to have confidence in the reconstruction of the curve. The shape of the curve cannot be inferred from the field measurements alone; as expected, tidal movement makes the pesticide concentration swing up and down. This result has important implications because the biological community would be subject to repetitive pulses of exposure to the chemicals. The baseline simulations can be used to derive a pulse-exposure metric by calculating the sum of ratios of the time average of the threshold-exceeding concentrations to the time average of the toxic threshold during intervals of above-threshold concentration. This metric is species specific and extrapolates laboratory toxicity data in order to compare pulse exposure to mortality rates measured in the field.