Biomedical subjects

C Bárbara

Publications and source records attributed to C Bárbara.

5 recordsLinked to original sources

PubMed2001

Diaphragmatic function in patients with chronic left ventricular failure.

The aim of this paper is to evaluate the function of respiratory muscles in-patients with chronic moderate left ventricular failure (LVF), and its contribution to the pathophysiology of dyspnea and fatigue. We have studied 20 male patients with LVF, classes II and III of New York Heart Association (NYHA), mean age 66.9+/-10 years (GI) and 19 male aged-matched controls without cardiopulmonary disease mean age 64.6+/-8.4 years (GII). The evaluation included (a) methods derived from volitional manoeuvres, maximal inspiratory pressures at Functional Residual Capacity; maximal expiratory pressures at total lung capacity (TLC); nasal sniff; oesophageal sniff and transdiaphragmatic pressures; (b) methods derived from non-volitional manoeuvres, using bilateral cervical magnetic stimulation of the phrenic nerves, measuring the following twitch pressures (oesophageal, gastric and the transdiaphragmatic). With volitional manoeuvres we have not found statistically significant differences between the two groups: maximal expiratory pressures (cmH(2)O), GI 138+/-42; GII 152+/-40; P=NS and maximal inspiratory pressures (cmH(2)O), GI 74.1+/-22; GII 85+/-16; P=NS. However, these values were significantly lower than those obtained with sniff manoeuvres, nasal sniff (cmH(2)O), GI 95.6+/-22; GII 99.6+/-16; P=NS and oesophageal sniff (cmH(2)O), GI 96.2+/-20; GII 97.5+/-18; P=NS. There were no significant differences between nasal sniff and oesophageal sniff. Using cervical magnetic stimulation, we also didn't find a significant difference for transdiaphragmatic twitch between groups, but the contribution of the diaphragm to the transdiaphragmatic pressure was lower in patients with LVF since the oesophageal twitch was lower (cmH(2)O), GI 11.4+/-3.4; GII 16.3+/-6.8; P<0,004. In conclusion, the contribution of the diaphragm to total ventilation in-patients with moderate LVF is preserved. However, its capacity to generate negative intra-thoracic pressures is decreased since there is a significant decrease in oesophageal twitch. So, it seems that the diaphragm is the first inspiratory muscle to be affected in patients with moderate LVF.

Journal Article↗

PubMed1994

[The repercussions of pulmonary congestion on ventilatory volumes, capacities and flows].

OBJECTIVES: To evaluate the effects of pulmonary congestion on pulmonary function. STUDY DESIGN: Prospective study performed in patients with left ventricular failure or mitral stenosis. MATERIAL AND METHODS: Forty-eight hospitalized patients were included suffering from pulmonary congestion either from left ventricular failure or mitral stenosis. While in hospital all patients were submitted to right heart catheterization by the Swan-Ganz method and also to an echocardiographic examination. Within 48 hours after the patients were submitted to the following lung function studies: lung volumes and capacities by the multi-breath helium dilution method and airway flows by pneumotachography. Respiratory symptoms were evaluated by the Medical Research Council Questionnaire and the functional class classified according to the NYHA. Correlations were made between the functional and clinical data. RESULTS: Regarding the cardiac evaluation patients presented with a mean pulmonary wedge pressure of 19.9 +/- 8.6 mmHg, a cardiac index of 2.5 +/- 0.8 l/min/m2, an end diastolic dimension of the left ventricle of 65.9 +/- 10.1 mm, and end systolic dimension of 51.2 +/- 12.2 mm, with a shortening fraction of 21.8 +/- 9.5%. The pulmonary evaluation showed a restrictive syndrome with a reduction in the mean values of the following parameters: total pulmonary capacity 71 +/- 14.4% of the predicted value (pv), forced vital capacity (FVC) 69.8 +/- 20.5% pv, and forced expiratory volume (FEV1) of 64 +/- 21.8% vp. The index FEV1/FVC was within the normal value of 72.7 +/- 9.7%. These lung function results did not correlate significantly with either the clinical, the hemodynamic or echocardiographic findings. CONCLUSION: In these group of patients pulmonary congestion led to the development of a restrictive syndrome which failed to correlate in severity with the duration of the disease, the pulmonary wedge pressure and the left ventricular function.

Aged↗

PubMed1994

[Pulmonary lymphangioleiomyomatosis].

The authors present a clinical case of Lymphangioleiomyomatosis of the lung. They analyse the clinical, radiological and functional features and comment on the evolution and therapeutic approach of this rare disorder. To the authors, lung involvement as well as therapeutic decision are important features that affect the prognosis.

Adult↗

PubMedDate not supplied

Respiratory muscle function in physically active elderly women.

This study was performed in 52 women, aged 60 to 76 years: 27 were engaged in a gymnastics program, 3 h a week, for at least 2 years; 25 were age-matched controls. All were lifelong nonsmokers, free of disease symptoms and lived independently at home; none had previously engaged in exercise programs. Spirometry included volumes, flows and maximal voluntary ventilation (MVV); maximal mouth pressures both inspiratory (MIP) and expiratory (MEP) were also measured. The two groups differed only in the mean value of MEP (cm of water) which was 107.7 +/- 37.3 S.D. in the active group and 87.4 +/- 22.8 S.D. in the controls (P = 0.028). MIP and MVV were also higher in the active group but the differences were not significant. However, a significant correlation between MVV and both MIP and MEP was only found in the active group, suggesting a relation between muscular endurance and strength. This exercise program, although not oriented towards the respiratory system, improved the performance of the respiratory muscles probably by an effect on the abdominal musculature.

Journal Article↗

PubMedDate not supplied

[Control of breathing].

The control system of breathing can be considered as a closed loop system, consisting of two subsystems: the controlling system and the controlled system. Both systems are defined by their input-output relationships. The controlling system is defined by the Respiratory Centers that are responsible for two separate, but overlapping, patterns: the automatic control pattern and the behavioral or voluntary control. In the controlling system the input is the blood gas value and the output is some parameters of ventilation. The controlled system is characterized by an input of ventilation and an output of blood gas values. In this closed loop system breathing is normally regulated by two anatomically distinct but functionally integrated elements, referred to as the metabolic and behavioral respiratory control systems. The metabolic control is concerned with blood gas homeostasis and the voluntary control relates with activities such as phonation and singing that use the ventilatory apparatus for purposes other than gas exchange.

Brain↗