Baroreflex Sensitivity Assessment Using the Sequence Method with Delayed Signals in End-Stage Renal Disease Patients.

Impaired baroreflex sensitivity (BRS) is partially responsible for erratic blood pressure fluctuations in End-Stage Renal Disease (ESRD) patients on chronic hemodialysis (HD), which is related to autonomic nervous dysfunction. The sequence method with delayed signals allows for the measurement of BRS in a non-invasive fashion and the investigation of alterations in this physiological feedback system that maintains BP within healthy limits. Our objective was to evaluate the modified delayed signals in the sequence method for BRS assessment in ESRD patients without pharmacological antihypertensive treatment and compare them with those of healthy subjects. We recruited 22 healthy volunteers and 18 patients with ESRD. We recorded continuous BP to obtain a 15-min time series of systolic blood pressure and interbeat intervals during the supine position (SP) and active standing (AS) position. The time series with delays from 0 to 5 heartbeats were used to calculate the BRS, number of data points, number of sequences, and estimation error. The BRS from the ESRD patients was smaller than in healthy subjects (p < 0.05). The BRS estimation with the delayed sequences also increased the number of data points and sequences and decreased the estimation error compared to the original time series. The modified sequence method with delayed signals may be useful for the measurement of baroreflex sensitivity in ESRD patients with a shorter recording time and maintaining an estimation error below 0.01 in both the supine and active standing positions. With this framework, it was corroborated that baroreflex sensitivity in ESRD is decreased when compared with healthy subjects.

Assessment of Factors Related to Diminished Appetite in Hemodialysis Patients with a New Adapted and Validated Questionnaire.

Appetite loss is a common phenomenon in end-stage renal disease (ESRD) patients undergoing maintenance hemodialysis (HD). We aimed to (i) adapt and validate a Spanish language version of the Council on Nutrition Appetite Questionnaire (CNAQ) and (ii) to identify psychological and biological factors associated with diminished appetite. We recruited 242 patients undergoing HD from four hemodialysis centers to validate the Spanish-translated version of the CNAQ. In another set of 182 patients from three HD centers, the Appetite and Diet Assessment Tool (ADAT) was used as the gold standard to identify a cut-off value for diminished appetite in our adapted questionnaire. The Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Distorted Thoughts Scale (DTS), Dialysis Malnutrition Score (DMS), anthropometric, values and laboratory values were also measured. Seven items were preserved in the adapted appetite questionnaire, with two factors associated with flavor and gastric fullness (Cronbach's alpha = 0.758). Diminished appetite was identified with a cut-off value ≤25 points (sensitivity 73%, specificity 77%). Patients with diminished appetite had a higher proportion of females and DMS punctuation, lower plasmatic level of creatinine, blood urea nitrogen, and phosphorus. Appetite score correlated with BDI score, BAI score and DTS. Conclusions: This simple but robust appetite score adequately discriminates against patients with diminished appetite. Screening and treatment of psychological conditions may be useful to increase appetite and the nutritional status of these patients.

Desarrollo y validación de un instrumento para la evaluación de distorsiones cognitivas en pacientes con insuficiencia renal crónica terminal / Development and validation of a questionnaire for the assessment of cognitive distortions among Mexican patients with end-stage renal disease

Background Psychological disturbances are common in patients with chronic renal failure (CRF). From the cognitive-behavioral theoretical perspective, they may be due largely to specific cognitive distortions (CD) that are likely to be modified by brief interventions. The aim of this study was to develop and validate an instrument for evaluation of specific CD among patients with CRF. Method A questionnaire with an encouraging phrase for each of five categories of CD (catastrophizing, dichotomous thinking, outside self-worth, negative self-labeling, and perfectionism) was developed. This was applied to 21 patients with CRF (11 women and 10 men). Based on the technique of natural semantic networks, a set of responses (defining words) with greater semantic weight to each sentence stimulus (core network) were identified and a pilot instrument was developed. This one was applied along with Beck's inventories of anxiety and depression among 255 patients with CRF (118 women, 137 men) attended in four different hospitals. Results The pilot questionnaire was composed of 46 items with greater semantic weight between 343 original defining words. Sixteen items were discarded for lack of ability to discriminate (1), low internal reliability (8) and duplicated in more than one factor (7). The final instrument of 30 items had an internal consistency of 0.93 for the total scale and more than 0.75 in all subscales. The five factors correlated positively and significantly with each other and with symptoms of anxiety and depression. Conclusions The instrument that is presented is a valid and reliable measure to assess five CD associated with depression and anxiety in Mexican patients with CRF. It is suggested as a useful tool for the design and evaluation of cognitive behavioral interventions for depression and anxiety among patients with CRF.

Antecedentes Las alteraciones psicológicas son frecuentes en los pacientes con insuficiencia renal crónica terminal (IRC). Desde la perspectiva teórica cognitivo-conductual, éstas pueden deberse en gran medida a distorsiones cognitivas específicas (DC), que son susceptibles de ser modificadas mediante intervenciones breves. El objetivo del presente estudio fue desarrollar y validar un instrumento de evaluación de las DC de pacientes con IRC. Método Se integró un cuestionario con una frase estímulo para cada una de cinco categorías de DC: catastrofismo, pensamiento dicotómico, autovalorización externa, autoetiquetización negativa y perfeccionismo. Éste se aplicó a 21 pacientes con IRC (11 mujeres y 10 hombres). Con base en la técnica de redes semánticas naturales, se identificó el conjunto de respuestas (palabras definidoras) con mayor peso semántico para cada frase estímulo (núcleo de la red), con las que se construyó el instrumento piloto. Éste se aplicó junto con los Inventarios de Ansiedad y Depresión de Beck a 255 pacientes con IRC (118 mujeres, 137 hombres) de cuatro centros hospitalarios. Resultados El cuestionario piloto se integró con 46 reactivos con mayor peso semántico de entre 343 palabras definidoras originales. Se descartaron 16 reactivos por falta de capacidad de discriminación (1), baja confiabilidad interna (8) y duplicidad en más de un factor (7). El instrumento final de 30 reactivos tuvo una consistencia interna de 0.93 para el total y mayor a 0.75 en todas las subescalas. Los cinco factores se correlacionaron positiva y significativamente entre sí y con los síntomas de ansiedad y depresión. Conclusiones El instrumento que se presenta es una medida válida y confiable para evaluar cinco DC asociadas con depresión y ansiedad en pacientes mexicanos con IRC. La medida se sugiere útil para el diseño y valoración de intervenciones cognitivo-conductuales para la depresión y ansiedad de los pacientes con IRC.