ABSTRACT
BACKGROUND: Hypertension is a complex chronic condition characterized by elevated arterial blood pressure. Management of hypertension includes non-pharmacologic strategies, which may include techniques that effectively reduce autonomic sympathetic activity. Respiratory exercises improve autonomic control over cardiovascular system and attenuate muscle metaboreflex. Because of these effects, respiratory exercises may be useful to lower blood pressure in subjects with hypertension. METHODS/DESIGN: This randomized, double-blind clinical trial will test the efficacy of inspiratory muscle training in reducing blood pressure in adults with essential hypertension. Subjects are randomly allocated to intervention or control groups. Intervention consists of inspiratory muscle training loaded with 40 % of maximum inspiratory pressure, readjusted weekly. Control sham intervention consists of unloaded exercises. Systolic and diastolic blood pressures are co-primary endpoint measures assessed with 24 h ambulatory blood pressure monitoring. Secondary outcome measures include cardiovascular autonomic control, inspiratory muscle metaboreflex, cardiopulmonary capacity, and inspiratory muscle strength and endurance. DISCUSSION: Previously published work suggests that inspiratory muscle training reduces blood pressure in persons with hypertension, but the effectiveness of this intervention is yet to be established. We propose an adequately sized randomized clinical trial to test this hypothesis rigorously. If an effect is found, this study will allow for the investigation of putative mechanisms to mediate this effect, including autonomic cardiovascular control and metaboreflex. TRIAL REGISTRATION: ClinicalTrials.gov NCT02275377 . Registered on 30 September 2014.
Subject(s)
Blood Pressure , Breathing Exercises , Essential Hypertension/therapy , Inhalation , Respiratory Muscles/physiopathology , Sympathetic Nervous System/physiopathology , Adult , Blood Pressure Monitoring, Ambulatory , Breathing Exercises/adverse effects , Clinical Protocols , Double-Blind Method , Essential Hypertension/diagnosis , Essential Hypertension/physiopathology , Female , Humans , Male , Middle Aged , Portugal , Research Design , Time Factors , Treatment OutcomeABSTRACT
Abstract Introduction: Individuals with chronic kidney disease (CKD) undergoing hemodialysis (HD) present low cardiorespiratory fitness and functional capacity. Metabolic changes, due to the disease, can result in a variety of pathophysiological conditions that favor the development of respiratory muscle weakness. However, very little is known about the performance of the respiratory muscles and the influence of HD on them. Aim: To evaluate and correlate pulmonary function, functional capacity and respiratory muscle strength in patients with CKD undergoing HD. Methods: Cross-sectional study comprising 23 patients with CKD, that met the following inclusion criteria: patients of both genders, who perform HD three times a week for a minimum period of three months. Respiratory muscle strength was evaluated using a respiratory pressure meter, lung function through spirometry and functional capacity through the 6-minute walk test (6MWT) before the HD session. Results: All patients were male and mean age was 50.2 ± 15.8 years. The median duration of HD was 3 (1.5 to 6.0) years. The mean values obtained in comparison to those predicted were MIP% 36.0 ± 13.6, MEP% 49.5 ± 15.8, FVC% 93.8 ± 21.1, FEV1% 93.7 ± 21.1, FVC/VEF1% 104.1 ± 10.3, and 6MWT% 66.33 ± 20.53. A statistically significant positive correlation was observed between the 6MWT and MIP (r = .63, p =.001) and MEP (r = .67, p < .001), between the MIP and MEP (r =.79, p < .001) and between the FEV1 and FVC (r = .91, p < .001). Conclusion: Patients with CKD undergoing HD present changes in respiratory muscle strength, with the predicted values decreasing for age and gender, as well as the distance covered in the 6MWT, although, with normal spirometric values. Functional capacity was dependent on respiratory muscle strength, as well as the values of MIP and MEP, and the values of FVC and FEV1.
Resumo Introdução: Indivíduos com doença renal crônica (DRC) submetidos a hemodiálise (HD) apresentam baixa capacidade cardiorrespiratória e funcional. As alterações metabólicas, devido a patologia, podem resultar em uma variedade de condições fisiopatológicas que favorecem o desenvolvimento de fraqueza muscular respiratória. No entanto, muito pouco é conhecido sobre o desempenho dos músculos respiratórios e a influência da HD sobre eles. Objetivo: Avaliar e correlacionar à função pulmonar, a capacidade funcional e a força muscular respiratória em pacientes com DRC submetidos à HD. Materiais e métodos: Estudo transversal composto por 23 pacientes com DRC, que se enquadravam nos seguintes critérios de inclusão: pacientes de ambos os sexos, que realizam HD três vezes por semana, por um período mínimo de três meses. Foi avaliada a força muscular respiratória através de manovuometria, função pulmonar por espirometria e a capacidade funcional pelo teste de caminhada dos 6 minutos (TC6) antes da sessão de HD. Resultados: Todos pacientes eram do sexo masculino e idade média de 50,2 ± 15,8 anos. O tempo mediano de HD era 3 (1,5 - 6,0) anos. Os valores médios alcançados de acordo com o previsto foi de %PImáx média foi 36,0±13,6, %PEmáx 49,5 ± 15,8, %CVF 93,8 ± 21,1, %VEF1 93,7 ± 21,1, %CVF/VEF1 104,1±10,3, %TC6 66,33 ± 20,53. Observou-se correlação estatisticamente significativa, positiva, entre o TC6 e PImáx (r = 0,63, p = 0,001), PEmáx (r = 0,67, p < 0,001) e entre PImax e PEmax (r = 0,79, p < 0,001) e VEF1 e CVF (r = 0,91, p < 0,001). Conclusão: Indivíduos portadores de DRC em HD sofrem alterações na força muscular respiratória, com diminuição dos valores previstos para sexo e idade, assim como na distância percorrida no TC6, porém, com os valores espirométricos dentro da normalidade. A capacidade funcional mostrou-se dependente da força muscular respiratória, assim como os valores entre PImáx e PEmáx e VEF1 e CVF.
ABSTRACT
Objetivos: avaliar e comparar a função pulmonar de pacientes submetidos à cirurgia de revascularização do miocárdio com e sem o uso de circulação extracorpórea. Métodos: a amostra foi composta por 40 pacientes submetidos à cirurgia de revascularização do miocárdio, classificados em dois grupos: com circulação extracorpórea (grupo CCEC ? 20 pacientes) ou sem circulação extracorpórea (grupo SCEC ? 20 pacientes). Registros espirométricos da capacidade vital forçada (CVF) e do volume expiratório forçado no primeiro segundo (VEF1) foram obtidos no período pré-operatório (considerado basal) e no primeiro, terceiro e quinto dias do período pós-operatório. Resultados: obser-vou-se que no geral os valores de CVF e VEF1 diminuíram no primeiro pós-operatório em relação ao basal (diferença média = 1,8±1,0, p<0,001 e 1,3±1,0, p<0,001, respectivamente), tendo recuperação parcial no terceiro e no quinto pós-operatórios, sem retornar aos valores iniciais (diferença média 1,2±1,1, p<0,001 e 0,9±0,9, p<0,001, respectivamente). Após controle para os valores basais, não foram observadas diferenças significativas entre os grupos CCEC e SCEC quanto à CVF e ao VEF1 no quinto dia pós-operatório. Conclusões: a cirurgia de revascularização do miocárdio associou-se a um decréscimo significante na função pulmonar em todos os pacientes, havendo recuperação parcial da CVF e do VEF1 no quinto pós-operatório para os dois grupos, porém sem retorno aos valores basais. Não se observou associação estatisticamente significativa entre realização de circulação extracorpórea e função pulmonar no quinto dia pós-operatório.
Aims: To evaluate and compare the pulmonary function of patients submitted to myocardial revascularization surgery, with and without the use of extracorporeal circulation. Methods: The sample comprised 40 patients submitted to myocardial revascularization surgery, classified into two groups, depending on whether extracorporeal circulation was used (wECC ? 20 patients) or not (nECC ? 20 patients). Spirometric recordings of forced vital capacity (FVC) and forced expiratory volume in the first second (FEV1) were obtained during the preoperative period (considered baseline) and on the first, third and fifth days postoperatively. Results: In general, the values of FVC and FEV1 diminished on the first day postoperatively compared to the baseline (mean difference = 1.8±1.0, p<0.001 and 1.3±1.0, p<0.001, respectively), with partial recovery on the third and fifth day postoperatively, with no return to the initial values (mean difference = 1.2±1.1, p<0.001 and 0.9±0.9, p<0.001, respectively). After controlling for baseline values, no significant differences were observed between the wECC and nECC groups as to FVC and FEV1 on the 5th day postoperatively. Conclusions: Myocardial revascularization surgery was associated to a significant decrease in pulmonary function in all patients, with partial recovery of FVC and FEV1 on the fifth day postoperatively for all groups, with no return to baseline values. No statistically significant association was found between extracorporeal circulation and pulmonary function on the fifth day postoperatively.