Chronic heart failure modifies respiratory mechanics in rats: a randomized controlled trial

ABSTRACT Objective To analyze respiratory mechanics and hemodynamic alterations in an experimental model of chronic heart failure (CHF) following myocardial infarction. Method Twenty-seven male adult Wistar rats were randomized to CHF group (n=12) or Sham group (n=15). Ten weeks after coronary ligation or sham surgery, the animals were anesthetized and submitted to respiratory mechanics and hemodynamic measurements. Pulmonary edema as well as cardiac remodeling were measured. Results The CHF rats showed pulmonary edema 26% higher than the Sham group. The respiratory system compliance (Crs) and the total lung capacity (TLC) were lower (40% and 27%, respectively) in the CHF rats when compared to the Sham group (P<0.01). There was also an increase in tissue resistance (Gti) and elastance (Hti) (28% and 45%, respectively) in the CHF group. Moreover, left ventricular end-diastolic pressure was higher (32 mmHg vs 4 mmHg, P<0.01), while the left ventricular systolic pressure was lower (118 mmHg vs 130 mmHg, P=0.02) in the CHF group when compared to the control. Pearson’s correlation coefficient showed a negative association between pulmonary edema and Crs (r=–0.70, P=0.0001) and between pulmonary edema and TLC (r=–0.67, P=0.0034). Pulmonary edema correlated positively with Gti (r=0.68, P=0.001) and Hti (r=0.68, P=0.001). Finally, there was a strong positive relationship between pulmonary edema and heart weight (r=0.80, P=0.001). Conclusion Rats with CHF present important changes in hemodynamic and respiratory mechanics, which may be associated with alterations in cardiopulmonary interactions.

Características clínicas e psicológicas de pacientes asmáticos de um Ambulatório de Pneumologia / Clinical and psychological characteristics of asthmatic patients of a Pulmonology Outpatient clinic / Características clínicas y psicológicas de pacientes asmáticos de un Ambulatorio de Neumología

A asma é uma doença crônica e intervenções psicológicas podem melhorar seu manejo. Este estudo objetiva correlacionar características clínicas e psicológicas dos asmáticos. Foram avaliados vinte e quatro adultos asmáticos em Ambulatório de Pneumologia, sendo administrados questionários de controle e qualidade de vida em asma, escalas de Otimismo/Pessimismo, Satisfação de Vida, Esperança Disposicional e Esperança de Staats. Controle da asma apresentou correlação estatisticamente significativa, com escore total (r=-0,69, p<0,01), domínios sintomas (r=-0,64, p<0,01) e emoções (r=-0,53, p<0,01) do Questionário de Qualidade de Vida e com o domínio estímulo ambiental (r=-0,42, p<0,05). Observou-se, também, que a dimensão hope-self (Esperança Staats) obteve correlações estatisticamente significativas com o Questionário de Controle de Asma (r=-0,45, p<0,05). O controle da asma apresentou relação importante com qualidade de vida. Os resultados mostraram que pacientes com maior controle da asma apresentaram maiores escores de esperança, mas não de otimismo...

Asthma is a chronic disease and psychological interventions can improve its management. This study aims to correlate clinical and psychological characteristics of asthmatic patients. Twenty-four patients were evaluated in the Pulmonology Outpatient Clinic of Santa Casa, in Porto Alegre, and were surveyed with asthma control and quality of life questionnaires, Optimism/Pessimism questionnaires, Satisfaction of life, Hope trace and Staats Hope scales. Asthma control demonstrated statistically significant correlation with the total score (r=-0,69, p<0,01), the domain symptoms (r=-0,64, p<0,01) and emotions (r=-0,53, p<0,01) of the Quality of Life Questionnaire and with the ambient domain (r=-0,42, p<0,05). The hope-self dimension (Staats Hope) showed statistically significant correlation with the Asthma Control Questionnaire (r=-0,45, p<0,05). Asthma control has an important relationship with quality of life. The results showed that patients with greater asthma control had higher scores of hope, but not optimism...

El asma es una enfermedad crónica e intervenciones psicológicas pueden mejorar su gestión. Este estudio pretende correlacionar características clínicas y psicológicas de los asmáticos. Se evaluaron veinticuatro asmáticos del Ambulatorio de Neumología de la Santa Casa de Porto Alegre, siendo administrados cuestionarios de control y calidad de vida en el asma, escalas de Optimismo/Pesimismo, Satisfacción con la Vida y Disposición de Esperanza e Esperanza Staats. El control del asma mostró una correlación estadísticamente significativa con la puntuación total (r=-0,69, p<0,01), el dominio síntomas (r=-0,64, p<0,01) y emociones (r=-0,53, p<0,01) del cuestionario de calidad de vida y con el dominio de los estímulos ambientales (r=-0,42, p<0,05). También se observó que la dimensión hope-self (Esperanza Staats) mostró correlación estadísticamente significativa con el Cuestionario de Control del Asma (r=-0,45, p<0,05). El control del asma presentó una relación importante con la calidad de vida. Los resultados mostraron que los pacientes con mayor control del asma tienen mayores puntuaciones en esperanza, pero no de optimismo...

Treinamento muscular inspiratório em pacientes com insuficiência cardíaca: metanálise de estudos randomizados / Inspiratory muscle training in patients with heart failure: meta-analysis of randomized trials

Pacientes com Insuficiência Cardíaca Crônica (ICC) podem ter menor força e resistência muscular inspiratória, o que pode contribuir para a intolerância ao exercício. O Treinamento Muscular Inspiratório (TMI) tem demonstrado efeitos benéficos nesses pacientes. Dessa forma, o objetivo desse estudo foi revisar sistematicamente os efeitos do TMI comparado a grupo controle (TMI placebo ou outra intervenção) em pacientes com ICC. A busca incluiu as bases MEDLINE, PEDro e Cochrane CENTRAL, além de referências de estudos publicados, de 1960 a 2011. Ensaios randomizados comparando TMI e grupo controle no tratamento de pacientes com ICC foram incluídos. O GRADE foi utilizado para determinar a qualidade da evidência para cada desfecho. Dos 119 artigos identificados, sete estudos foram incluídos. O TMI aumentou a distância percorrida no teste de caminhada de 6 minutos [69 m (IC95%: 7,21 a 130,79)] (evidência muito baixa) e a pressão inspiratória máxima [23,36 cmH20 (IC95%: 11,71 a 35,02)] comparado aos grupos controles (evidência baixa). Entretanto, o TMI promoveu uma melhora significativa no consumo máximo de oxigênio somente nos estudos que realizaram TMI por 12 semanas, comparado a nenhuma carga inspiratória em pacientes com fraqueza muscular inspiratória [3,02 ml/kg/min-1 (IC95%: 0,43 a 5,61)]. Assim, concluiu-se que o TMI melhora capacidade funcional e força muscular inspiratória, merecendo consideração como uma intervenção adicional em pacientes com ICC. Entretanto, estudos maiores e com maior qualidade são necessários para esclarecer o potencial benefício do TMI nessa população.

Patients with chronic heart failure (CHF) may have lower inspiratory muscle strength and endurance, which may contribute to exercise intolerance. Inspiratory muscle training (IMT) can have beneficial effects on these patients. Thus, the aim of this study was to systematically review the effects of IMT compared to control groups (placebo-IMT or another intervention) in patients with CHF. A search of databases (MEDLINE, Cochrane CENTRAL and PEDro) and references of published studies, from 1960 to 2011, was conducted. Randomized trials comparing IMT to control groups in the treatment of patients with CHF were included. The GRADE approach was used to determine the quality of evidence for each outcome. Of 119 articles identified, 7 studies were included. IMT increased the distance walked in the six-minute walk test [69 m (95% CI: 7.21 to 130.79)] (very low evidence) and maximal static inspiratory pressure [23.36 cmH20 (95% CI: 11.71 to 35.02)] (low evidence) compared to control groups. However, IMT provides a significant improvement in peak oxygen consumption only in the studies that performed IMT for 12 weeks against no inspiratory load in patients with inspiratory muscle weakness [3.02 ml/kg/min-1 (95% CI: 0.43 to 5.61)]. IMT improves functional capacity and inspiratory muscle strength thereby deserving consideration as an additional intervention in patients with CHF. Larger and better-designed studies, however, are needed to clarify the potential benefit of IMT in this patient population.