Vanessa Resqueti

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.

Comparação entre o manovacuômetro nacional e o importado para medida da pressão inspiratória nasal

BACKGROUND the measurement of nasal inspiratory pressure, known as the sniff test, was developed as a new test of inspiratory muscle strength, mainly used in neuromuscular conditions. The test is easy to be performed and noninvasive. Despite the clinical importance of assessment of nasal inspiratory pressure a national equipment is not available to assess it. OBJECTIVES to compare a national with a foreign manovacuometer in assessing the nasal inspiratory pressure (sniff test) in healthy subjects. METHODS 18 subjects were evaluated (age 21.44 ± 2.8 years, BMI 23.4 ± 2.5 kg/m² , FVC 102.1 ±1 0.3% pred, FEV1 98.4 ± 1% pred). We performed two measures of nasal inspiratory pressure using two different manovacuometer: a national and a foreign. All subjects performed the tests at the same time of day, in different days being the order of the testes established randomly. It was used the paired t test, Pearson correlation and the Bland-Altman plots for statistical analysis considering a 5% significance level. RESULTS The averages observed for the two measures of nasal pressures were 125 ± 42.4 cmH2O for the foreign equipment, and 131.7 ± 2 8.7 cmH2O for the national equipment. The Pearson correlation showed significant correlation between the means with a coefficient of r=0.63. The t test showed no significant differences between both measurements (p>0,05). The BIAS ± SD found in Bland-Altman plot analysis was 7 cmH2O with limits of agreement between -57.5 cmH2O and 71.5 cmH2O. CONCLUSION the results suggest that the national electronic device is feasible and safe to the sniff test measurement in healthy subjects.

Avaliação clínica da capacidade do exercício em pacientes com doença pulmonar obstrutiva crônica

CONTEXTUALIZACAO: A doenca pulmonar obstrutiva cronica (DPOC) se caracteriza por ser uma afeccao multissistemica que leva a uma diminuicao na tolerância ao exercicio do paciente pneumopata. Atualmente, a Fisioterapia Respiratoria dispoe de uma grande variedade de testes validados que tem como caracteristica a sua simplicidade, praticidade e baixo custo. OBJETIVO: Descrever os testes de campo mais utilizados em pacientes com DPOC para avaliar a capacidade de exercicio e a atividade fisica, assim como alguns testes que potencialmente poderiam ser adotados na avaliacao clinica destes pacientes. CONCLUSOES: Para poder justificar a qualidade do trabalho do profissional de Fisioterapia Respiratoria, deve-se incorporar os testes utilizados e validados internacionalmente. Alem disso, e importante escolher o teste mais adequado para medir a capacidade do exercicio e, sobretudo, realizar um seguimento cuidadoso da evolucao do paciente.

Variabilidade da frequência cardíaca em pacientes com Distrofia Miotônica tipo 1

BACKGROUND Cardiac involvement is common in myotonic dystrophy (MD) patients. Heart rate variability (HRV) is a simple and reliable technique that can be useful for studying the influence of the autonomic nervous system on the heart. OBJECTIVE Study heart rate variability in patients with type 1 MD. METHODS We studied HRV during 5-minute recordings in MD patients and in a healthy control group. We analyzed frequency domains (LF and HF) in normalized units (nu) and sympathovagal balance, in the sitting and supine position. RESULTS Seventeen patients (10 men and 7 women) and seventeen matched healthy individuals (10 men and 7 women) were studied. Sympathetic and parasympathetic modulations of the heart increased in male MD patients from supine to sitting position in 19% of LFnu and the LF/HF ratio rose by 42.3%. In the sitting position, male MD patients exhibited significantly higher sympathovagal balances in 50.9% compared to healthy control individuals. HRV was influenced by both gender and disease. Gender influenced LFnu in the supine position while the LF/HF ratio and HFnu were affected in both positions. Post hoc analyses showed that gender significantly impacts MD patients and healthy individuals in different ways (p < 0.01). The low frequency domain in the sitting position (LFnu) was significantly influenced by the disease. CONCLUSION The results of this study suggest that the sympathetic drive in middle-aged male MD patients who are not severely impaired and present moderate disease duration seems to be greater than in healthy matched individuals.

Muscle impairment in neuromuscular disease using an expiratory/inspiratory pressure ratio.

BACKGROUND: Neuromuscular diseases (NMDs) lead to different weakness patterns, and most patients with NMDs develop respiratory failure. Inspiratory and expiratory muscle strength can be measured by maximum static inspiratory pressure (PImax) and maximum static expiratory pressure (PEmax), and the relationship between them has not been well described in healthy subjects and subjects with NMDs. Our aim was to assess expiratory/inspiratory muscle strength in NMDs and healthy subjects and calculate PEmax/PImax ratio for these groups. METHODS: Seventy (35 males) subjects with NMDs (amyotrophic lateral sclerosis, myasthenia gravis, and myotonic dystrophy), and 93 (47 males) healthy individuals 20–80 y of age were evaluated for anthropometry, pulmonary function, PImax, and PEmax, respectively. RESULTS: Healthy individuals showed greater values for PImax and PEmax when compared with subjects with NMDs. PEmax/PImax ratio for healthy subjects was 1.31 ± 0.26, and PEmax%/PImax% was 1.04 ± 0.05; for subjects with NMDs, PEmax/PImax ratio was 1.45 ± 0.65, and PEmax%/PImax% ratio was 1.42 ± 0.67. We found that PEmax%/PImax% for myotonic dystrophy was 0.93 ± 0.24, for myasthenia gravis 1.94 ± 0.6, and for amyotrophic lateral sclerosis 1.33 ± 0.62 when we analyzed them separately. All healthy individuals showed higher PEmax compared with PImax. For subjects with NMDs, the impairment of PEmax and PImax is different among the 3 pathologies studied (P < .001). CONCLUSIONS: Healthy individuals and subjects with NMDs showed higher PEmax in comparison to PImax regarding the PEmax/PImax ratio. Based on the ratio, it is possible to state that NMDs show different patterns of respiratory muscle strength loss. PEmax/PImax ratio is a useful parameter to assess the impairment of respiratory muscles in a patient and to customize rehabilitation and treatment.

Heart Rate Variability at rest and after the 6-minute walk test (6MWT) in children with cystic fibrosis

BACKGROUND Cystic fibrosis (CF) is a multisystem disease that affects the cardiorespiratory system and the cardiac autonomic control may be altered at rest and after a submaximal exercise. OBJECTIVE To assess the cardiac autonomic control by heart rate variability (HRV) analysis before and after a 6-minute walk test (6MWT). METHOD Thirteen children diagnosed with Cystic Fibrosis (CFG) aged 12±2.7 years (FEV1/FVC: 0.83±0.11, FEV1: 71.4±21 %pred) and 12 healthy children (control group-CG) aged 11.4±2.4 years (FEV1/FVC: 0.91±0.12, FEV1: 91.6±17.4 %pred) were included in the study. HRV was evaluated prior to and immediately after the 6MWT and the heart rate recovery assessed on the first and second minute after test. RESULTS Prior to exercise, CF patients presented higher values for the variables LF(nu) (53.2±15.0 vs. 32.8±7.9, p=0.0003) and LF/HF (1.25±0.72 vs. 0.49±0.18, p<0.006) as well as lower values of HF(%) (25.4±18.4 vs. 53±9.6, p=0.002) and HF(nu) (47.3±14.7 vs. 68.3±8.7, p0.001) when compared to CG. After the 6MWT, both groups demonstrated HRV recovery to baseline levels; however, the differences between CFG and CG were maintained for the variables LF(ms 2) (846.7±754.8 vs. 345.6±197.2, p=0.02); LF(%) (35.4±8.1 vs. 25.9±6.2, p=0.002); LF(nu) (60.0±16.3 vs. 34.9±8.7, p<0.0001); HF(%) (27.4±13.7 vs. 48.1±6.3, p=0.0003); HF(nu) (40.4±15.8 vs. 65.6±8.2, p=0.0003) and LF/HF (1.9±1.7 vs. 0.5±0.2, p=0.0001). CONCLUSIONS Children with cystic fibrosis exhibited predominance of sympathetic activity at rest that persisted after the 6-minute walking test when compared to the control group.

Variação diurna de parâmetros de função pulmonar e de força muscular respiratória em pacientes com DPOC

OBJECTIVE To evaluate the magnitude of diurnal changes in the parameters of pulmonary function and respiratory muscle strength/endurance in a sample of patients with COPD. METHODS A group of 7 patients underwent spirometry, together with determination of MIP and MEP, at two distinct times (between 8:00 and 8:30 a.m. and between 4:30 and 5:00 p.m.) on a single day. Between assessments, the patients remained at rest in the laboratory. RESULTS In accordance with the Global Initiative for Chronic Obstructive Pulmonary Disease staging system, COPD was classified as moderate, severe, and very severe in 1, 3, and 3 of the patients, respectively. From the first to the second assessment, there were significant decreases in FVC, FEV1, and MEP (of 13%, 15%, and 10%, respectively), as well as (less than significant) decreases in PEF, MIP, and maximal voluntary ventilation (of 9%, 3%, and 11%, respectively). CONCLUSIONS In this sample of COPD patients, there were diurnal variations in the parameters of pulmonary function and respiratory muscle strength. The values of FEV1, FVC, and MEP were significantly lower in the afternoon than in the morning.

Confiabilidade do teste da caminhada de seis minutos em pacientes com miastenia gravis generalizada

Este estudo objetivou determinar a confiabilidade do teste da caminhada de seis minutos (TC6M) como um teste de capacidade funcional em pacientes com miastenia gravis generalizada (MG). Foram selecionados 11 pacientes com MG - 5 homens, 6 mulheres - com idade de 55±9 anos, avaliados inicialmente quanto a funcao fulmonar, que se submeteram a tres TC6M em dias diferentes. Durante e/ou apos cada teste foram medidas frequencia cardiaca e saturacao de oxigenio (por oximetro portatil), sensacao de dispneia (pela escala de Borg) e distância percorrida. Nos tres testes as distâncias percorridas foram 498 m, 517 m e 520 m (respectivamente 99%, 103% e 104% do valor predito). Em media, a frequencia cardiaca, dispneia e saturacao de oxigenio mostraram comportamento constante nos tres testes. Foram encontradas alta confiabilidade relativa, com coeficiente de correlacao interclasse maior que 0,90 entre os testes (TC6M1-TC6M2, 0,960; TC6M1-TC6M3, 0,945; e TC6M2-TC6M3, 0,970) e confiabilidade absoluta de 4%, 3,5% e 4,8%, com reprodutibilidade de 11%, 9,8% e 13,4%, respectivamente para o primeiro, segundo e terceiro testes. Os limites superiores e inferiores de concordância e o valor medio das medias das diferencas (bias) calculados pelo teste de Bland-Altman mostraram-se clinicamente aceitaveis. Conclui-se que o TC6M se mostrou seguro, confiavel e reprodutivel, podendo ser aplicado para avaliacao e seguimento da tolerância ao exercicio em pacientes com MG generalizada.

Air Stacking: A Detailed Look Into Physiological Acute Effects on Cough Peak Flow and Chest Wall Volumes of Healthy Subjects

BACKGROUND: Air stacking (AS) is a lung insufflation method that requires the use of a manual insufflator to provide air volumes higher than inspiratory capacity. Neuromuscular patients benefit the most from the maneuver; however, the acute effects of AS in healthy subjects are still unclear. METHODS: Twenty healthy subjects (8 males) were studied by optoelectronic plethysmography to investigate the immediate effects of AS on cough peak flow, operational volume variations, distribution of these volumes in the chest wall compartments (pulmonary rib cage, abdominal rib cage, and abdominal), breathing pattern, and shortening velocity of the respiratory muscles during a protocol that included vital capacity maneuvers and spontaneous coughs before and after AS. RESULTS: Statistically significant increases in cough peak flow (P < .03) and inspiratory capacity (P < .001) were found immediately after AS. During its application, the pulmonary rib cage compartment was the largest contributor (P = .002) to chest wall volume displacement. A significant increase in chest wall tidal volume (P < .001), mainly in the pulmonary rib cage (P < .001), was observed. Significant increases (P < .001) in end-inspiratory chest wall volume were observed with main distribution in pulmonary (P < .001) and abdominal rib cage (P = .01). Significant increases in shortening velocity index of inspiratory muscles (P < .001), expiratory muscles (P < .001), and diaphragm (P < .001) were also observed. In addition, significant decreases in expiratory time (P < .001) and increases in duty cycle (P = .02), breathing frequency (P = .02), minute ventilation (P < .001), maximum inspiratory (P < .001), and expiratory flow (P < .001) were observed. CONCLUSIONS: In healthy subjects, cough peak flow and chest wall volumes can be increased immediately after the application of the AS maneuver.

Effects of Air Stacking Maneuver on Cough Peak Flow and Chest Wall Compartmental Volumes of Subjects With Amyotrophic Lateral Sclerosis

OBJECTIVES To assess the acute effects of air stacking on cough peak flow (CPF) and chest wall compartmental volumes of persons with amyotrophic lateral sclerosis (ALS) versus healthy subjects positioned at 45° body inclination. DESIGN Cross-sectional study with a matched-pair design. SETTING University hospital. PARTICIPANTS Persons (N=24) with ALS (n=12) and age-matched healthy subjects (n=12). MAIN OUTCOMES MEASURES CPF, chest wall compartmental inspiratory capacity, chest wall vital capacity, chest wall tidal volume and operational volumes, breathing pattern, and percentage of contribution of the compartments to the inspired volume were measured by optoelectronic plethysmography. RESULTS Compared with healthy subjects, significantly lower CPF (P=.007), chest wall compartmental inspiratory capacity (P<.001), chest wall vital capacity (P<.001), and chest wall tidal volume (P<.001) were found in subjects with ALS. Immediately after air stacking, CPF (P<.001) and chest wall compartmental inspiratory capacity (P<.001) significantly increased in both groups, with values returning to basal only in healthy subjects. After air stacking, the abdominal compartment (P=.004) was determined to be responsible for the inspired volume in subjects with ALS. Significantly higher chest wall vital capacity (P=.05) was observed in subjects with ALS 5 minutes after air stacking, with the rib cage compartment (P=.049) being responsible for volume change. No differences were found in chest wall vital capacity and compartmental volumes of healthy subjects. Chest wall tidal volume (P<.001) significantly increased during the protocol in the healthy subjects, mainly because of end-inspiratory (P<.001) and abdominal volumes (P=.008). No significant differences were observed in percentage of contribution of the compartments to the inspired volume and end-expiratory volume of both groups. No significant differences were found in chest wall tidal volume, operational volume, and breathing pattern in persons with ALS. CONCLUSIONS Air stacking is effective in increasing CPF, chest wall compartmental inspiratory capacity, and chest wall vital capacity of persons with ALS with no hyperinflation. Differences in compartmental volume contributions are probably because of lung and chest wall physiological changes.