Rogério Baumgratz de Paula

Exercício físico em pacientes dialisados

Pacientes portadores de doenca renal cronica (DRC) submetidos a tratamento dialitico apresentam alteracoes fisicas e psicologicas que predispoem ao sedentarismo. Nesta populacao, a prescricao rotineira de exercicios fisicos nao e uma pratica frequente, especialmente no nosso pais. No entanto, alguns autores tem demonstrado que um programa de exercicios para estes pacientes contribui para o melhor controle da hipertensao arterial, da capacidade funcional, da funcao cardiaca, da forca muscular e, consequentemente, da qualidade de vida. Alem dos beneficios relacionados ao sistema cardiovascular, a realizacao do exercicio traz beneficios secundarios, pois quebra a monotonia do procedimento, melhora aderencia e pode aumentar a eficacia da dialise. Na presente revisao, os autores discutem aspectos da realizacao de exercicios fisicos em pacientes portadores de DRC em dialise e apresentam dados iniciais de sua experiencia com a aplicacao de exercicios supervisionados durante as sessoes de hemodialise.

Treinamento aeróbico melhora a capacidade funcional de pacientes em hemodiálise crônica

BACKGROUND In the general population, regular practice of physical exercises is associated with improved physical capacity and reduction of cardiovascular events. Concerning patients with chronic kidney disease, a population with significant impairment of physical capacity and high rates of cardiovascular mortality, few studies have evaluated the effects of physical activity. OBJECTIVE To evaluate the effect of aerobic exercise during hemodialysis on the physical capacity and blood pressure of patients with chronic renal failure. METHODS We evaluated 14 patients with chronic kidney disease under hemodialysis, before and after 12 weeks of aerobic exercise performed during hemodialysis sessions. Patients underwent ambulatory blood pressure monitoring for 24 hours, 6-minute walk test and cardiopulmonary exercise test before and after the exercise period. RESULTS After the exercise, there was a significant increase in the distance walked during the 6-minute walk test from 509 +/- 91.9 m to 555 +/- 105.8 m, and a significant reduction in systolic blood pressure of 151 +/- 18.4 mmHg to 143 +/- 14.7 mmHg, diastolic blood pressure of 94 +/- 10.5 mmHg to 91 +/- 9.6 mmHg and average arterial pressure from 114 +/- 13.0 mmHg to 109 +/- 11.4 mmHg. CONCLUSION Aerobic exercise conducted during hemodialysis sessions contributed to the improvement of physical capacity and control of hypertension in patients with chronic kidney disease.

Exercise Training During Hemodialysis Reduces Blood Pressure and Increases Physical Functioning and Quality of Life

Hypertension and cardiovascular diseases are highly prevalent in hemodialysis patients and are associated with the reduction of physical functioning and quality of life. We evaluated the effects of supervised aerobic exercise training on physical functioning, blood pressure, quality of life, and laboratory data in hemodialysis patients. Fourteen patients were evaluated at the beginning and after 12 weeks of stretching exercises (control phase) and at the end of 12 weeks of aerobic exercise training performed during hemodialysis sessions (intervention phase). Patients underwent a 6-min walking test (6MWT), 24-h ambulatory blood pressure monitoring, a Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) quality of life questionnaire, and blood sample collections. After the intervention phase, the 6MWT distance increased from 508.7 +/- 91.9 m to 554.9 +/- 105.8 m (P = 0.001), systolic and diastolic blood pressure decreased respectively from 150.6 +/- 18.4 mm Hg to 143.5 +/- 14.7 mm Hg and from 94.6 +/- 10.5 mm Hg to 91.4 +/- 9.7 mm Hg (P < 0.05), while hemoglobin levels increased from 10.8 +/- 1.2 g/dL to 11.6 +/- 0.8 g/dL (P < 0.05). Moreover, there was a significant increase in the physical functioning, social functioning, and mental health dimensions of the SF-36. Aerobic exercise training during hemodialysis increased physical functioning, reduced blood pressure levels, and improved the control of anemia and quality of life in patients with end-stage renal disease.

Constant Work-Rate Test to Assess the Effects of Intradialytic Aerobic Training in Mildly Impaired Patients With End-Stage Renal Disease: A Randomized Controlled Trial

OBJECTIVE To investigate if high-intensity constant work rate (CWR) would constitute a more appropriate testing strategy compared with incremental work rate (IWR) to assess the effectiveness of intradialytic aerobic training in patients with end-stage renal disease (ESRD). DESIGN Randomized controlled trial. SETTING Nephrology unit at the university hospital. PARTICIPANTS Patients (N=28; 47.0±11.9y) under hemodialysis (4.4±4.3y) were randomly assigned to exercise and control groups. INTERVENTION Patients included in the exercise group underwent a moderate-intensity intradialytic aerobic training program 3 times per week for 12 weeks. MAIN OUTCOME MEASURES Cardiopulmonary and perceptual responses were obtained during an IWR and a high-intensity CWR test to the limit of tolerance on a cycle ergometer. RESULTS Training-induced increases in peak oxygen uptake (Vo(2)peak) and time to exercise intolerance (Tlim). Mean improvement in Tlim (97.4%±75.6%) was significantly higher than increases in Vo(2)peak (12%±11.3%) (P<.01); in fact, while Tlim improved 50% to 200% in 9 of 12 patients, Vo(2)peak increases were typically in the 15% to 20% range. CWR test revealed lower metabolic, ventilatory, cardiovascular, and subjective stresses at isotime; in contrast, submaximal responses during the incremental work rate (at the gas exchange threshold) remained unaltered after training. CONCLUSIONS A laboratory-based measure of endurance exercise capacity (high-intensity CWR test to Tlim) was substantially more sensitive than oxygen uptake at the peak IWR test to unravel the physiologic benefits of an intradialytic aerobic training program in mildly impaired patients with ESRD.

Efeito do exercício aeróbico durante as sessões de hemodiálise na variabilidade da frequência cardíaca e na função ventricular esquerda em pacientes com doença renal crônica

INTRODUCAO: Pacientes com doenca renal cronica (DRC) sob tratamento hemodialitico apresentam diminuicao da variabilidade da frequencia cardiaca (VFC) que representa um fator de risco independente para a mortalidade cardiaca, especialmente a morte subita. OBJETIVO: Avaliar o efeito do exercicio aerobico, realizado durante as sessoes de hemodialise, na VFC e na funcao ventricular esquerda de pacientes portadores de DRC. METODOS: Foram avaliados 22 pacientes randomizados em dois grupos: exercicio (n = 11; 49,6 ± 10,6 anos; 4 homens) e controle (n = 11; 43,5 ± 12,8; 4 homens). Os pacientes do grupoexercicio foram submetidos a tres sessoes semanais de exercicio aerobico, realizado nas duas horas iniciais da hemodialise, durante 12 semanas. Para a analise da VFC e da funcao ventricular esquerda, todos os pacientes foram submetidos aos exames de Holter de 24 horas e ecocardiograma, respectivamente. RESULTADOS: Apos 12 semanas de protocolo, nao foi observada diferenca significante em nenhum dos parametros da VFC nos dominios do tempo e da frequencia em ambos os grupos. A fracao de ejecao aumentou de modo nao significante nos pacientes do grupo-exercicio (67,5 ± 12,6% vs. 70,4 ± 12%) e diminuiu nao significantemente nos pacientes do grupo-controle (73,6 ± 8,4% vs. 71,4 ± 7,6%). CONCLUSAO: A realizacao de 12 semanas de exercicio aerobico, durante as sessoes de hemodialise, nao modificou a VFC e nao promoveu melhora significante na funcao ventricular esquerda.

Aldosterone Antagonist Decreases Blood Pressure and Improves Metabolic Parameters in Obese Patients With the Metabolic Syndrome

To the Editor: The association between obesity and hypertension is well established. Epidemiologic studies have reported that up to 75% of the risk for human essential hypertension is attributable to excess weight. Experimental and clinical studies have shown that excess weight raises blood pressure (BP) and that weight loss is the most effective nonpharmacologic strategy for lowering BP in obese hypertensive patients. The mechanisms that link excessive weight gain and increased BP are poorly understood, however. Proposed mechanisms include impairment of renalpressure natriuresis, sympathetic nervous system activation, functional and structural renal abnormalities, and activation of the renin-angiotensinaldosterone system (RAAS). Studies in experimental animals and humans have shown that obesity activates most components of the RAAS. It has been established that the treatment of obese patients with an angiotensinconverting enzyme inhibitor attenuates sodium retention and volume expansion as well as high BP. These findings support the hypothesis that angiotensin II plays a significant role in stimulating renal sodium reabsorption and thus contributes to obesity-induced hypertension. The involvement of aldosterone (ALDO) in sodium retention and hypertension in obesity has only recently been proposed. In a model of chronic dietary-induced obesity in dogs, ALDO blockade decreased glomerular hyperfiltration and sodium retention and attenuated hypertension, indicating that ALDO plays a role in the pathogenesis of obesity-induced hypertension. ALDO has also been implicated in the development of certain deleterious effects on the cardiovascular system. Some studies have demonstrated that ALDO induces endothelial lesions and cardiac and renal fibrosis, and that these effects can be attenuated by ALDO antagonism. Furthermore, ALDO blockade has been shown to be associated with improved BP control in patients with refractory hypertension, a disorder affecting a population that includes a high percentage of obese individuals. To the best of our knowledge, no previous study has been designed to specifically evaluate the BP response to ALDO blockade in obese and hypertensive patients with the metabolic syndrome (MetS). The primary goal of the present study was to determine whether ALDO blockade, achieved through the use of the antagonist spironolactone, attenuates hypertension in obese and hypertensive patients with MetS.

Identifying potential drug interactions in chronic kidney disease patients

INTRODUCTION Drug interactions (DIs) are common in clinical practice and are directly related to factors such as polypharmacy, aging, hepatic metabolism and decreased renal function. Individuals with chronic kidney disease (CKD) often require multiple classes of drugs being at important risk for the development of DIs. OBJECTIVE Identify potential interactions among drugs prescribed to patients with CKD on conservative treatment, and factors associated with their occurrence. METHODS Observational cross-sectional study, with analysis of 558 prescriptions. Potential DIs were identified by the database MICROMEDEX®, software that provides an internationally known pharmacopoeia. RESULTS There was a predominance of males (54.7%), seniors (69.4%), stage 3 CKD (47.5%), overweight and obese patients (66.7%). The most prevalent comorbidities were hypertension (68.5%) and diabetes mellitus (31.9%). Potential DIs were detected in 74.9% of prescriptions. Among the 1364 DIs diagnosed, 5 (0.4%) were contraindicated and 229 (16.8%) of greater severity, which need immediate intervention. Interactions of moderate and low severity were identified in 1049 (76.9%) and 81 (5.9%) prescriptions, respectively. The probability of one DI increased by 2.5 times for each additional drug (CI = 2.18 to 3.03). Obesity, hypertension, diabetes as well as advanced stage of CKD were risk factors strongly associated with DI occurrence. CONCLUSION Drug associations in individuals with CKD were related to high prevalence of serious DIs, especially in the later stages of the disease.

Efeito da perda de peso sobre a hemodinâmica renal em portadores da síndrome metabólica

Danielle Guedes Andrade Ezequiel Fundacao IMEPEN Rua Jose Lourenco Kelmer, 1.300/SL – Sao Pedro Juiz de Fora – MG – Brazil Zip code 36036-330 E-mail: daniezequiel@hotmail.comThis study was undertaken at Nucleo Interdisciplinar de Estudos e Pesquisas em Nefrologia – NIEPEN of UFJF.The authors report no conflicts of interest.

Physical Activity in Hemodialysis Patients Measured by Triaxial Accelerometer

Different factors can contribute to a sedentary lifestyle among hemodialysis (HD) patients, including the period they spend on dialysis. The aim of this study was to evaluate characteristics of physical activities in daily life in this population by using an accurate triaxial accelerometer and to correlate these characteristics with physiological variables. Nineteen HD patients were evaluated using the DynaPort accelerometer and compared to nineteen control individuals, regarding the time spent in different activities and positions of daily life and the number of steps taken. HD patients were more sedentary than control individuals, spending less time walking or standing and spending more time lying down. The sedentary behavior was more pronounced on dialysis days. According to the number of steps taken per day, 47.4% of hemodialysis patients were classified as sedentary against 10.5% in control group. Hemoglobin level, lower extremity muscle strength, and physical functioning of SF-36 questionnaire correlated significantly with the walking time and active time. Looking accurately at the patterns of activity in daily life, HDs patients are more sedentary, especially on dialysis days. These patients should be motivated to enhance the physical activity.

Can Nephrologists Use Ultrasound to Evaluate the Inferior Vena Cava? A Cross-Sectional Study of the Agreement between a Nephrologist and a Cardiologist

Background/Aims: The costs and the need for a specialist impair the implementation of ultrasonography for evaluating the inferior vena cava (IVC) to assess the volemic status in hemodialysis patients. We investigated whether a nephrologist with limited ultrasound training can accurately assess the IVC in patients undergoing hemodialysis. Methods: A cardiologist and a nephrologist consecutively measured the indexed IVC expiratory diameter (VCDi) and the IVC collapsibility index (IVCCI) of 52 patients during hemodialysis sessions. In protocol I, the nephrologist used a regular ultrasound system (RUS) and the cardiologist used a cardiovascular ultrasound equipment; in protocol II, the machines were interchanged. Pearson and kappa coefficients and the interexaminer agreement by the Bland-Altman method were calculated. Results: The VCDi measurements showed a strong correlation in both protocols (r = 0.88 and 0.84 in protocols I and II, respectively). The volemic classifications were excellent in protocol I (kappa = 0.82 and 0.93 by VCDi and IVCCI, respectively) and substantial in protocol II (kappa = 0.77 and 0.75 by VCDi and IVCCI, respectively). The interexaminer agreement on the VCDi measurements was very good in both protocols. Conclusions: Ultrasound evaluation of the IVC can be performed by nephrologists using an RUS to assess the volemic status in hemodialysis patients.