Larissa de Andrade Carvalho

Valores de referência da pressão inspiratória nasal em indivíduos saudáveis no Brasil: estudo multicêntrico

OBJECTIVE: The objectives of this study were to determine reference values for sniff nasal inspiratory pressure (SNIP) and to propose reference equations for the population of Brazil. METHODS: We evaluated 243 healthy individuals (111 males and 132 females), between 20 and 80 years of age, with an FVC and FEV1/FVC ratio > 80% and > 85% of the predicted value, respectively. All of the subjects underwent respiratory muscle strength tests to determine MIP, MEP, and SNIP. RESULTS: We found that SNIP values were higher in males than in females (p < 0.05) and that SNIP correlated negatively with age, for males (r = -0.29; p < 0.001) and for females (r = -0.33; p < 0.0001). Linear regression also revealed that age influenced the predicted SNIP, for males (R2 = 0.09) and females (R2 = 0.10). We obtained predicted SNIP values that were higher than those obtained for other populations. CONCLUSIONS: We have devised predictive equations for SNIP to be used in adults (20-80 years of age) in Brazil. These equations could help minimize diagnostic discrepancies among individuals.

Chest wall regional volume in heart failure patients during inspiratory loaded breathing.

Were evaluated individuals divided into two groups: we studied chronic heart failure (CHF) (19 patients with CHF plus cardiomegaly) and control (12 healthy volunteers) during performance of inspiratory loaded breathing (ILB). We evaluated: spirometry, functional capacity through the six-minute walk test (6MWT), and distribution of thoracoabdominal volumes via optoelectronic plethysmography (OEP), namely volume variations of pulmonary rib cage (Vrc,p), abdominal rib cage (Vrc,a), and abdomen (Vab). In each compartment, the percentage contributions of right and left sides were also calculated. During ILB, patients with heart failure were characterized by a significant reduction of the Vrc,a volume variations compared to the control group. Correlations were found between left %Vrc,a on the left side measured during ILB and left ventricular ejection fraction (r=0.468; p=0.049), and dyspnea after the 6MWT (r=-0.878; p<0.01).Then, patients with CHF and cardiomegaly are characterized by a reduced mobility in left part of the lower part of the rib cage, that contributes leading to increased perception of dyspnea during submaximal exercise.

Acute effects of incremental inspiratory loads on compartmental chest wall volume and predominant activity frequency of inspiratory muscle.

AIM This research aims to analyze the acute effect of incremental inspiratory loads on respiratory pattern and on the predominant activity frequency of inspiratory muscle, taking into account differences in gender responses. Optoelectronic Plethysmography was performed during loads in 39 healthy subjects (20 women), placing 89 markers on the thoracic-abdominal wall to obtain total and regional volumes. Surface electromyography (SEMG) was taken simultaneously on the Sternocleidomastoid and Diaphragm muscles, to calculate the predominant muscle activity frequency through wavelet analysis. Inspiratory loads were performed using Threshold(®)with 2 min of breathing at different levels, ranging from a load of 10 cmH(2)O plus 5 cmH(2)O to 40 cmH(2)O or fatigue. RESULTS Inspiratory Time increased during loads. Total and compartmental volumes increased with different regions, changing at different loads. These changes in volume occur earlier in women (20 cmH(2)O) than in men (30 cmH(2)O). The predominant activity frequency of Sternocleidmastoid muscle decreased at 30 cmH(2)O, while Diaphragm activity decreased at 40 cmH(2)O. CONCLUSION The acute effects of incremental inspiratory loads are increases of total and regional volumes and inspiratory time. As for muscle activity, the predominant activity frequency declined in Sternocleidomastoid and Diaphragm muscles, but at different loads. Such respiratory and SEMG patterns and gender differences should be considered when clinical interventions are performed.

Noninvasive Ventilation Before Maximum Exercise Test Increases Exercise Tolerance in Subjects With Heart Failure: A Crossover Study

OBJECTIVE To evaluate the effect of noninvasive ventilation (NIV) on exercise performance in individuals with heart failure (HF). DESIGN Crossover, blind, randomized controlled trial with allocation concealment. SETTING University-based research laboratory. PARTICIPANTS Participants (N=24) with New York Heart Association class II and III left heart failure and with a mean age of 51.8±10.2 years (women: n=8; men: n=16). INTERVENTIONS Ventilatory support attached to the face of the individual via a facemask prior to cardiopulmonary exercise test (CPET) was administered at 2 pressure levels for 30 minutes. Inspiratory pressure of 15cmH2O and expiratory pressure of 5cmH2O were applied. MAIN OUTCOME MEASURES Maximal oxygen uptake, maximum heart rate, variation between the initial and maximum heart rates, CPET duration, and recovery time oxygen consumption. RESULTS Differences were observed in maximal oxygen consumption (nonintervention phase: 18.3±4.4mL·kg-1·min-1 vs NIV phase: 20.6±4.9mL·kg-1·min-1, P=.01), heart rate (nonintervention phase: 127.3±20.9 beats per minute vs NIV phase: 134.7±19.5 beats per minute, P=.04), and heart rate variation (nonintervention phase: 63.3%±19.3% vs NIV phase: 69.7%±16.6%, P=.02). Moreover, differences in cardiopulmonary exercise time (nonintervention phase: 7.4±1.5min vs NIV phase: 8.3±1.7min, P=.01) and oxygen consumption recovery time (nonintervention phase: 2.8±1.0min vs NIV phase: 2.4±0.8min, P=.01) were observed. CONCLUSIONS NIV elicited beneficial effects in the HF population that included increased exercise tolerance, recovery time optimization, and improved chronotropic and respiratory reserves.

Influência dos corticosteroides inalatórios nas pressões respiratórias máximas de crianças escolares asmáticas

INTRODUCTION: The inhaled corticosteroid (IC) is the mean therapy used for the preventive and maintenance treatment of asthma. Overdose or prolonged use of IC can cause some collateral effects as remission in bone growth, adrenal suppression and myopathy. OBJECTIVES: To evaluate the influence of inhaled corticosteroids in the inspiratory and expiratory strength in asthmatic school children. MATERIALS AND METHODS: A cross-sectional, observational study, that included 60 children between 6 to 12 years divided into three groups: control (CG), asthma (AG) and children whose used IC for at least three months (AG+IC). The maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were measured in 3 different days with 12 days between them. RESULTS: The mean ± SD of MIP in the third day was - (65.4 ± 21.9), - (74.9 ± 19.5) and - (80.7 ± 21.5) cmH2O to the AG, AG+IC and CG, respectively. The MIP in the AG was lesser than in the CG (p < 0.05). The mean ± SD of MEP in the third day was 52.7 ± 14.8; 61.7 ± 17.4; and 75.6 ± 18.4 cmH2O to the AG, AG+IC and CG, respectively. The MEP was superior in the CG than in the AG (p < 0.05). The MEP was superior in the CG than the AG+CI (p < 0.05). CONCLUSIONS:The results suggest that IC promotes a major control of pulmonary hiperinflation with the increase of MIP in asthmatic children, but decrease the MEP probably by the effect in the type II muscles fibers.