Fisiopatología del síncope neuralmente mediado / Pathophysiology of neurally-mediated syncope

Introducción: El síncope neuralmente mediado (SNM) se define como una pérdida súbita y transitoria del estado de alerta debido a una caída brusca de la presión arterial (PA). Objetivos: Describir los mecanismos putativos fisiopatológicos responsables del SNM, el papel del barorreflejo (BR) y la interacción de sus variables hemodinámicas principales: frecuencia cardiaca (FC) y PA. Desarrollo: Existe una desregulación episódica en el control de las variables hemodinámicas (FC y PA) mediadas por el barorreflejo. Durante la bipedestación activa existe una caída profunda y transitoria de la PA sistólica (PAS) debida a la acción de la gravedad sobre la columna de sangre y probablemente también a una vasodilatación refleja producida por inhibición del reflejo vasosimpático. Las anormalidades del BR en el SNM pueden ser debidas a una mayor intensidad de la caída de la PA al ponerse de pie o a una vasoconstricción retardada o incompleta debido a un reflejo vasosimpático insuficiente o retardado. Conclusiones: Los pacientes con SNM tienen en reposo y antes del síncope un estado de hiperactividad simpática. Durante el ortostatismo activo o la inclinación pasiva hay taquicardia excesiva seguida de bradicardia e hipotensión severa. La recuperación de la caída de la PAS está retardada o incompleta

Introduction: Neurally-mediated syncope (NMS) is defined as a transient loss of consciousness due to an abrupt and intermittent drop in blood pressure (BP). Objectives: This study describes the putative pathophysiological mechanisms giving rise to NMS, the role of baroreflex (BR), and the interaction of its main haemodynamic variables: heart rate (HR) and BP. Development: Episodic dysregulation affects control over the haemodynamic variables (HR and BP) mediated by baroreflex mechanisms. During active standing, individuals experience a profound transient drop in systolic BP due to the effect of gravity on the column of blood and probably also because of reflex vasodilation. Abnormalities in the BR in NMS could be due to a more profound drop in BP upon standing, or to delayed or incomplete vasoconstriction resulting from inhibited or delayed sympathetic activity. Conclusions: Sympathetic hyperactivity is present in patients with NMS at rest and before syncope. During active standing or passive tilting, excessive tachycardia may be followed by bradycardia and profound hypotension. Recovery of systolic BP is delayed or incomplete

Pathophysiology of neurally-mediated syncope. / Fisiopatología del síncope neuralmente mediado.

INTRODUCTION: Neurally-mediated syncope (NMS) is defined as a transient loss of consciousness due to an abrupt and intermittent drop in blood pressure (BP). OBJECTIVES: This study describes the putative pathophysiological mechanisms giving rise to NMS, the role of baroreflex (BR), and the interaction of its main haemodynamic variables: heart rate (HR) and BP. DEVELOPMENT: Episodic dysregulation affects control over the haemodynamic variables (HR and BP) mediated by baroreflex mechanisms. During active standing, individuals experience a profound transient drop in systolic BP due to the effect of gravity on the column of blood and probably also because of reflex vasodilation. Abnormalities in the BR in NMS could be due to a more profound drop in BP upon standing, or to delayed or incomplete vasoconstriction resulting from inhibited or delayed sympathetic activity. CONCLUSIONS: Sympathetic hyperactivity is present in patients with NMS at rest and before syncope. During active standing or passive tilting, excessive tachycardia may be followed by bradycardia and profound hypotension. Recovery of systolic BP is delayed or incomplete.

[Validation of a Spanish version of the Edinburgh Postnatal Depression Scale]. / Validación de una versión en español de la Escala de Depresión Postnatal de Edimburgo.

INTRODUCTION: The objective of this study is to validate a version in Spanish of the Edinburgh Postnatal Depression Scale (EPDS) in Peruvian women with less than 1 year of delivery. METHOD: We administered the EPDS and the SCID section for diagnosis of major depression according to DSM-IV criteria to 321 women within the first year of postpartum. RESULTS: We found that the optimum cut-off score of the EPDS for the studied population was 13.5. With this value the sensitivity was 84.21% and the specificity 79.47% for diagnosis of major depression. No woman with score lower than 7.5 had major depression (sensitivity and negative predictive value were 100%). The correlation coefficient between the EPDS score and the number of criterion A symptoms for major depression according to DSM-IV was 0.4478. The Cronbach's alpha coefficient was 0.7043. The items that had more predictive power for postpartum depression were those regarding worries, ability to cope, panic, cry and optimism. CONCLUSIONS: The version in Spanish of the EPDS performed adequately in Peruvian women.

Validación de una versión en español de la Escala de Depresión Postnatal de Edimburgo / Validation of a Spanish version of the Edinburgh Postnatal Depression Scale

Introducción. El objetivo del estudio es validar una traducción al español de la Escala de Depresión Postnatal de Edimburgo (EPDS) en mujeres peruanas que han dado a luz hace menos de un año. Metodología. Se aplicó la EPDS y la sección del SCID para diagnosticar depresión mayor según criterios del DSM-IV a 321 mujeres que estaban dentro del primer año postparto. Resultados. Se encontró que el punto de corte óptimo de la EPDS para la población estudiada era 13,5; con este valor se obtuvo una sensibilidad de 84,21 por ciento y una especificidad de 79,47 por ciento para el diagnóstico de depresión mayor. Ninguna mujer con puntuación menor de 7,5 tuvo depresión mayor (sensibilidad y valor predictivo negativo 100 por ciento). Se halló un coeficiente de correlación de 0,4478 entre la puntuación de la EPDS y el número de síntomas del criterio A de depresión mayor del DSM-IV. El coeficiente alfade Cronbach fue 0,7043. Los ítems que tuvieron mayor poder predictivo para depresión postparto fueron los referidos a preocupación, capacidad para afrontar problemas, pánico, llanto y optimismo. Conclusiones. La versión en español de la EPDS funciona adecuadamente en mujeres peruanas (AU)

A controlled trial of bismuth subsalicylate in infants with acute watery diarrheal disease.

BACKGROUND: Bismuth subsalicylate is a common constituent of over-the-counter medications for diarrhea. However, it is uncertain whether bismuth offers any more benefit than standard oral rehydration therapy with early feeding. METHODS: We conducted a placebo-controlled, randomized trial to evaluate the effect of bismuth subsalicylate (100 or 150 mg per kilogram of body weight per day for up to 5 days) on the duration and volume of acute watery diarrhea in 275 male infants and young boys (mean age, 13.5 months). Serum salicylate and bismuth levels were monitored throughout the study and were also measured two weeks after discharge. All the patients received fluid replacement by the oral route and early feeding of easily digestible foods with high caloric density. RESULTS: Diarrhea stopped within 120 hours of admission in 74 percent of the patients given placebo, 89 percent of those given 100 mg of bismuth per kilogram (P = 0.009 vs. the placebo group), and 88 percent of those given 150 mg of bismuth per kilogram (P = 0.019 vs. the placebo group). As compared with the patients given placebo, those given bismuth had significant reductions in their total stool output (P = 0.015), total intake of oral rehydration solution (P = 0.013), and duration of hospitalization (P = 0.005); there was no significant difference between the two groups given bismuth in these clinical outcomes. All measurements of bismuth and salicylate concentrations in blood were well below concentrations considered toxic. No adverse reactions were seen. CONCLUSIONS: Treatment with bismuth subsalicylate decreases the duration of diarrhea and is a safe and effective adjunct to oral rehydration therapy for infants and young children with acute watery diarrhea.