Reliability and Validity of Maximal Respiratory Pressures.

BACKGROUND: Maximal respiratory pressure is used to assess the inspiratory and expiratory muscles strength by using maximal inspiratory pressure (PImax ) and maximal expiratory pressure (PEmax). This study aimed to summarize and evaluate the reliability and validity of maximal respiratory pressure measurements. METHODS: This systematic review followed the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) recommendations and was reported by using the PRISMA checklist. Studies published before March 2023 were searched in PubMed and EMBASE databases. RESULTS: A total of 642 studies were identified by using the online search strategy and manual search (602 and 40, respectively). Twenty-three studies were included. The level of evidence for test-retest reliability was moderate for PImax and PEmax (intraclass correlation coefficient > 0.70 for both), inter-rater reliability was low for PImax and very low for PEmax (intraclass correlation coefficient > 0.70 for both), and the measurement error was very low for PImax and PEmax. In addition, concurrent validity presented a high level of evidence for PImax and PEmax (r > 0.80). CONCLUSIONS: Only concurrent validity of maximal respiratory pressure measured with the manometers evaluated in this review presented a high level of evidence. The quality of clinical studies by using maximal respiratory pressure would be improved if more high-quality studies on measurement properties, by following well established guidelines and the COSMIN initiative, were available.

Maximal respiratory pressures: Measurements at functional residual capacity in individuals with different health conditions using a digital manometer.

BACKGROUND: Measuring maximal respiratory pressure is a widely used method of investigating the strength of inspiratory and expiratory muscles. OBJECTIVES: To compare inspiratory pressures obtained at functional residual capacity (FRC) with measures at residual volume (RV), and expiratory pressures obtained at FRC with measures at total lung capacity (TLC) in individuals with different health conditions: post-COVID-19, COPD, idiopathic pulmonary fibrosis (IPF), heart failure (CHF), and stroke; and to compare the mean differences between measurements at FRC and RV/TLC among the groups. METHODS: Inspiratory and expiratory pressures were obtained randomly at different lung volumes. Mixed factorial analysis of covariance with repeated measures was used to compare measurements at different lung volumes within and among groups. RESULTS: Seventy-five individuals were included in the final analyses (15 individuals with each health condition). Maximal inspiratory pressures at FRC were lower than RV [mean difference (95% CI): 11.3 (5.8, 16.8); 8.4 (2.3, 14.5); 11.1 (5.5, 16.7); 12.8 (7.1, 18.4); 8.0 (2.6, 13.4) for COVID-19, COPD, IPF, CHF, and stroke, respectively] and maximal expiratory pressures at FRC were lower than TLC [mean difference (95% CI): 51.9 (37.4, 55.5); 60.9 (44.2, 77.7); 62.9 (48.1, 77.8); 58.0 (43.9, 73.8); 57.2 (42.9, 71.6) for COVID-19, COPD, IPF, CHF, and stroke, respectively]. All mean differences were similar among groups. CONCLUSION: Although inspiratory and expiratory pressures at FRC were lower than measures obtained at RV/TLC for the five groups of health conditions, the mean differences between measurements at different lung volumes were similar among groups, which raises the discussion about the influence of the viscoelastic properties of the lungs on maximal respiratory pressure.

Acute effects of expiratory positive airway pressure on exercise tolerance in patients with COPD.

OBJECTIVE: To evaluate the acute effects of expiratory positive airway pressure (EPAP) on exercise tolerance, dyspnea, leg discomfort, and breathing pattern in patients with COPD. METHODS: Fifteen patients with COPD were assessed with the following three different protocols: EPAP of 7.5 cmH2O used during a constant cycle ergometer exercise test (Protocol-1); EPAP of 7.5 cmH2O used for 15 minutes before the test (Protocol-2); and a sham system without pressure used for 15 minutes before the test (Protocol-3). Dyspnea and leg discomfort were assessed using Borg scale, whereas breathing pattern by optoelectronic plethysmography. Statistical analyses were performed using generalized estimating equations and Bonferroni tests (α = 5%), considering the protocols (1, 2, and 3) and moment (resting and the end of exercise). RESULTS: Exercise tolerance was lower in protocol 1: 108 ± 45 seconds compared to protocols 2: 187 ± 99 seconds (p= .011) and 3: 183 ± 101 seconds (p= .021). No difference was observed between protocols 2 and 3 (p> .999). Dyspnea in protocol 1: 7.0 ± 2.08 was higher than protocols 2: 4.10 ± 2.45 (p= .001) and 3: 3.90 ± 2.21 (p< .001), but no differences were observed between protocols 2 and 3 (p> .999). No significant difference was observed for leg discomfort among the protocols (p= .137). There were no statistically significant differences for most variables of breathing pattern among the protocols. CONCLUSION: A reduction on exercise tolerance and an increase in dyspnea were found with EPAP of 7.5 cm H2O during a constant cycle ergometer exercise test in patients with COPD.

New method for evaluating maximal respiratory pressures: Concurrent validity, test-retest, and inter-rater reliability.

BACKGROUND: Maximal respiratory pressures (MRP) obtained at functional residual capacity (FRC) may reflect the real respiratory muscle pressure. OBJECTIVES: To evaluate concurrent validity, test-retest, and inter-rater reliability of MRP performed with a new instrument in healthy individuals, and to compare values obtained at different volumes in healthy individuals and individuals with COPD. METHODS: MRP of 100 healthy individuals were obtained using the TrueForce and the MicroRPM® at residual volume (RV) and total lung capacity (TLC) to evaluate concurrent validity. MRP were obtained at FRC using the TrueForce to evaluate reliability. Comparisons of inspiratory pressure values (FRC compared to RV) and expiratory pressure values (FRC compared to TLC) were performed with 100 healthy individuals and 15 individuals with COPD. RESULTS: The intraclass correlation coefficient (ICC) was 0.77 and 0.86 for concurrent validity for inspiratory and expiratory pressures, respectively. Test-retest reliability showed an ICC of 0.87 for inspiratory pressure, and 0.78 for expiratory pressure; inter-rater reliability showed an ICC of 0.91 for inspiratory pressure, and 0.84 for expiratory pressure. Measurements performed at RV and TLC were higher when compared to FRC [mean difference (95%CI)= -8.30 (-11.82, -4.78) cmH2O; -37.29 (-42.63, -31.96) cmH2O] in healthy individuals, and -11.09 (-15.83, -6.35) cmH2O; -57.14 (-71.05, -43.05) cmH2O in COPD, for inspiratory and expiratory pressures, respectively. CONCLUSION: MRP performed with the TrueForce presented good concurrent validity, good test-retest reliability, excellent inter-rater reliability for inspiratory pressure and good inter-rater reliability for expiratory pressure. MRP were lower when obtained at FRC for healthy individuals and with COPD.

Rib cage distortion and dynamic hyperinflation during two exercise intensities in people with COPD.

BACKGROUND: The relationship between rib cage (RC) motion abnormalities, dynamic hyperinflation (DH), and exercise capacity in people with COPD is controversial. AIM: To investigate RC distortion and operational chest wall volumes during moderate and high constant-rate exercises in people with COPD. METHODS: Seven male participants [median(Q1-Q3) age: 63(60.0-66.0) years; FEV1: 39.0(38.0-63.0)% of predicted] performed a symptom-limited incremental exercise testing on cycle ergometer, followed by constant-rate tests (60 % and 80 % of peak work rate). Optoelectronic plethysmography was used to evaluate RC distortion: phase angle-PhAng, inspiratory phase ratio-PhRIB, expiratory phase ratio-PhREB; and chest wall volumes: end-inspiratory volume-Vei and end-expiratory volume-Vee. RESULTS: PhRIB and PhREB significantly increased during both constant-rate exercise tests, without difference between them. In general, Vei of the chest wall significantly increased in both exercise intensities while Vee did not change. CONCLUSIONS: The occurrence of RC distortion seemed not to limit the exercise capacity in people with COPD evaluated, and it was present even in the absence of DH.

Inspiratory muscle training reduces dyspnea during activities of daily living and improves inspiratory muscle function and quality of life in patients with advanced lung disease.

Aim: To evaluate the effects of an inspiratory muscle training (IMT) program on dyspnea during activities of daily living, inspiratory muscle function, functional capacity, and quality of life in patients with advanced lung disease (ALD).Methods: Pre-post interventional study in which patients with ALD from the Advanced Lung Disease and Pre Lung Transplantation Ambulatory Clinic were included. Patients performed home-based high-intensity interval IMT for 8 weeks (two sessions per day, daily). In each session, patients performed two sets of 30 breaths, with a 2-min rest between sets. Dyspnea during activities of daily life, primary outcome - assessed by the London Chest Activity of Daily Living scale-LCADL, inspiratory muscle function (MIP and endurance test), distance on the 6-min walking test [6MWD], and quality of life (St George Respiratory Questionnaire [SGRQ]) were measured pre-IMT, post-IMT, and 3 months after the intervention (follow-up).Results: Dyspnea during activities of daily living significantly decreased after 8 weeks of IMT (LCADLpre = 31.5 [IQR = 23-37.25], LCADLpost = 26 [IQR = 20.75-32], LCADLfollow-up = 30.5 [IQR = 20-35]; p < .03). After IMT, there was an improvement in inspiratory muscle strength (p < .001) and endurance (p < .001). Functional capacity evaluated using the 6MWD increased but did not reach significance (p = .79) There was also a significant improvement in quality of life, as demonstrated by the SGRQ (p < .004).Conclusions: Our results suggest that IMT was able to reduce dyspnea during activities of daily living, as well as improve inspiratory muscle function, and quality of life in patients with ADL, and these benefits were sustained for 3 months.

Early CPAP protocol in preterm infants with gestational age between 28 and 32 weeks: experience of a public hospital.

BACKGROUND: The use of continuous positive airway pressure (CPAP) applied early after birth improves several outcomes when compared with intubation and invasive mechanical ventilation. "Early CPAP" protocols vary in relation to the pressure level, type of interface used, and studied sample. OBJECTIVE: This study compared intubation rate, exogenous surfactant use, and hospitalization length (among other variables) prior to and after adopting an "early CPAP" protocol in preterm infants with gestational age between 28 and 32 weeks, using intermediate pressures and short binasal prongs. METHODS: This was a retrospective study conducted in a public university hospital in Brazil. All preterm infants with gestational age between 28 and 32 weeks were included in the study. The newborns born between January 2011 and December 2012, prior to the protocol being implemented, were considered the historical control group, and those born after implementation, between February 2013 and August 2014 were considered the intervention group. RESULTS: The participants in both groups had similar baseline characteristics (p > 0.05). There were significant reductions in intubation rate (89% versus 73%, p = 0.02), exogenous surfactant use (86% versus 67%, p = 0.02), and median (Q1 - Q3) days of invasive mechanical ventilation [4 (2 - 14) versus 1 (0.15-9), p = 0.01] and length of hospital stay in days [56 (42-77) versus 42 (35-71), p = 0.02]. CONCLUSIONS: The findings demonstrate positive outcomes of the early CPAP protocol. This protocol used simple and affordable equipment available in the hospital which could easily be reproduced in other centers, generating better outcomes for preterm infants and reducing hospital expenses.

Effects of inspiratory muscle training on resting breathing pattern in patients with advanced lung disease.

AIM: The aim of this study was to evaluate the effects of interval high intensity inspiratory muscle training (IMT) on resting breathing pattern in patients with advanced lung disease. METHODS: IMT was performed daily and training load set at 50 % of the maximal inspiratory pressure. Participants were evaluated at pre-IMT, post 8 weeks of IMT and follow-up (3 months after the end of IMT). Breathing pattern (volume and time variables as well as percentages of contribution to tidal volume) was evaluated by Optoelectronic Plethysmography at rest. Friedman test was used to verify the differences between the three time-points (p < 0.05). RESULTS: Nineteen patients (54 ± 16 years old; 5 males) were evaluated at pre-IMT and post-IMT and fourteen were assessed at follow-up. There was no significant difference (p > 0.05) in any comparison for all evaluated breathing pattern variables at the three time-points. CONCLUSION: Resting breathing pattern was not significantly changed after 8 weeks of IMT in patients with advanced lung disease.

Reference values of sniff nasal inspiratory pressure in healthy children.

OBJECTIVE: To determine reference values of sniff nasal inspiratory pressure (SNIP) in healthy children. METHODS: This cross-sectional observational study included healthy children aged 6 to 11 years of both sexes. The volunteers underwent a pulmonary function test to rule out respiratory disorders. Respiratory muscle strength was measured using maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP), respectively, with MIP close to functional residual capacity (FRC) and residual volume, while MEP to total lung capacity. SNIP was performed through the nostril contralateral to the occlusion, close to FRC. Two 6-minute walk tests were performed to assess functional exercise capacity. RESULTS: The sample comprised 121 healthy children (62 girls); 54% presented body mass index (BMI) percentile less than 85th and 46% more than equal to 85th percentile, higher than expected. SNIP values were similar between sexes (91.1 ± 21.0 cmH2 O in girls and 87.7 ± 19.4 cmH2 O in boys; P = .36) as well as the means of lower limits of normal (56.88 cmH2 O for girls and 56.66 cmH2 O for boys). Girls presented SNIP measurements larger than those of the MIP of FRC (P < .0001), while boys presented similar mean values for both. We found a positive correlation between SNIP and BMI percentile (r = .25, P = .04) in girls, unlike boys, in whom no correlation was observed. CONCLUSIONS: SNIP reference values and mean lower limits of normal were defined for healthy children aged 6 to 11. BMI percentile seems to positively influence the inspiratory muscle strength measured by SNIP in girls only.

Sustained maximal inspiration has similar effects compared to incentive spirometers.

PURPOSE: To compare the effects of flow incentive spirometer (FIS), volume incentive spirometer (VIS), and sustained maximal inspiration exercise (SMI) on breathing pattern, chest wall motion, and thoracoabdominal asynchrony. METHODS: Sixteen healthy adults aged 27.63 ± 5.26 years were evaluated by optoelectronic plethysmography in the supine position with trunk inclination of 45° during quiet breathing and during exercise performance. RESULTS: In the comparisons among exercises, VIS promoted a significantly higher inspiratory time and lower mean inspiratory flow compared with FIS. The rating of perceived exertion according to the Borg Scale was significantly higher after the performance of FIS compared with VIS. Regarding asynchrony, none of the exercises caused changes in thoracoabdominal synchrony between the rib cage and abdomen. However, both devices significantly reduced the asynchrony between the pulmonary and abdominal rib cage compared with quiet breathing. CONCLUSION: SMI exercise was equivalent to incentive spirometers and may be an interesting alternative for clinical use in cases in which it is not possible to acquire the devices.

Effects of Diaphragmatic Breathing With and Without Pursed-Lips Breathing in Subjects With COPD.

BACKGROUND: Breathing exercises, such as diaphragmatic breathing and pursed-lips breathing, play a role in some individuals with COPD and might be considered for those patients who are unable to exercise. However, in the literature are reports of some adverse effects of diaphragmatic breathing in patients with COPD. Thus, the purpose of this study was to assess the effects of diaphragmatic breathing and diaphragmatic breathing combined with pursed-lips on chest wall kinematics, breathlessness, and chest wall asynchrony in subjects with COPD, and also to assess whether the combination of both exercises reduces the adverse effects of diaphragmatic breathing while maintaining its benefits. METHODS: Seventeen subjects with COPD, mean ± SD, 65 ± 7 y of age, with a history of smoking and clinical stability without hospitalization or symptoms of exacerbation in the past 4 wk, were evaluated. On day 1, participants' characteristics were collected, and they learned diaphragmatic breathing and its combination with pursed-lips breathing. On day 2, the participants were evaluated by optoelectronic plethysmography with the participants in the seated position while performing breathing exercises. RESULTS: Diaphragmatic breathing and diaphragmatic breathing plus pursed-lips breathing promoted a significant increase in chest wall tidal volume and its compartments as well as a reduction in breathing frequency compared with quiet breathing. No significant changes were observed in dyspnea or end-expiratory volume of the chest wall. A significant increase in asynchrony (inspiratory-expiratory phase ratio) was observed during diaphragmatic breathing and diaphragmatic breathing plus pursed-lips breathing compared with quiet breathing, with no differences observed between the exercises. CONCLUSIONS: Despite the increase in asynchrony, both breathing exercises were able to improve chest wall volumes without affecting dyspnea. The combination of exercises maintained the benefits but did not reduce the adverse effects of diaphragmatic breathing.

The effects of inspiratory muscle training based on the perceptions of patients with advanced lung disease: a qualitative study.

BACKGROUND: Advanced lung disease is a chronic non-neoplastic disease that compromises activities of daily living. Treatment includes pulmonary rehabilitation and inspiratory muscle training. Studies have shown the effectiveness of inspiratory muscle training in lung disease patients, but literature is scarce on the patients' perceptions about this topic. OBJECTIVE: To explore the perceptions of patients with advanced lung disease about inspiratory muscle training. METHODS: Qualitative study. Interviews were conducted using a semi-structured questionnaire regarding topics on the participation of patients in inspiratory muscle training and on daily activities performed before and after training. Interviews were transcribed and analyzed according to thematic content analysis. RESULTS: Ten patients (eight women and 2 men, ranging in age from 27 to 89 years) with inspiratory muscle weakness (maximal inspiratory pressure=44±13.9cmH2O) were included. Five patients were diagnosed with Chronic Obstructive Pulmonary Disease, two with bronchiectasis and three with pulmonary fibrosis. All patients completed at least 80% of the total training sessions. The reports were grouped into four thematic categories: (1) impact of inspiratory muscle training on breathlessness (e.g., "I wasn't feeling as tired as I previously felt."); (2) change in daily activities (e.g., "I needed to go to the supermarket, I felt less tired doing it."); (3) improved mobility (e.g., "I could not stand for long periods […] walking, for example […] Now I stand more, I have more capability."); and (4) increased communication (e.g., "More power, right? Even in speaking […] When I could, I felt my voice coming out better."). CONCLUSION: There were improvements in breathlessness, daily activities, mobility, and communication, which positively affected the psychological and social aspects of the patients.

Effects of non-invasive ventilation and posture on chest wall volumes and motion in patients with amyotrophic lateral sclerosis: a case series.

BACKGROUND: The effects of non-invasive ventilation (NIV) on the breathing pattern and thoracoabdominal motion of patients with amyotrophic lateral sclerosis (ALS) are unknown. OBJECTIVES: 1) To analyze the influence of NIV on chest wall volumes and motion assessed by optoelectronic plethysmography in ALS patients and 2) to compare these parameters in the supine and sitting positions to those of healthy individuals (without NIV). METHOD: Nine ALS patients were evaluated in the supine position using NIV. In addition, the ALS patients and nine healthy individuals were evaluated in both sitting and supine positions. Statistical analysis was performed using the paired Student t-test or Wilcoxon test and the Student t-test for independent samples or Mann-Whitney U test. RESULTS: Chest wall volume increased significantly with NIV, mean volume=0.43 (SD=0.16)L versus 0.57 (SD=0.19)L (p=0.04). No significant changes were observed for the pulmonary rib cage, abdominal rib cage, or abdominal contribution. The index of the shortening velocity of the diaphragmatic muscle, mean=0.15 (SD=0.05)L/s versus 0.21 (SD=0.05)L/s (p<0.01), and abdominal muscles, mean=0.09 (SD=0.02)L/s versus 0.14 (SD=0.06)L/s (p<0.01), increased during NIV. Comparisons between the supine and sitting positions showed similar changes in chest wall motion in both groups. However, the ALS patients presented a significantly lower contribution of the abdomen in the supine position compared with the controls, mean=56 (SD=13) versus 69 (SD=10) (p=0.02). CONCLUSIONS: NIV improved chest wall volumes without changing the contribution of the chest wall compartment in ALS patients. In the supine position, ALS patients had a lower contribution of the abdomen, which may indicate early diaphragmatic dysfunction.

Effects of non-invasive ventilation and posture on chest wall volumes and motion in patients with amyotrophic lateral sclerosis: a case series

ABSTRACT Background The effects of non-invasive ventilation (NIV) on the breathing pattern and thoracoabdominal motion of patients with amyotrophic lateral sclerosis (ALS) are unknown. Objectives 1) To analyze the influence of NIV on chest wall volumes and motion assessed by optoelectronic plethysmography in ALS patients and 2) to compare these parameters in the supine and sitting positions to those of healthy individuals (without NIV). Method Nine ALS patients were evaluated in the supine position using NIV. In addition, the ALS patients and nine healthy individuals were evaluated in both sitting and supine positions. Statistical analysis was performed using the paired Student t-test or Wilcoxon test and the Student t-test for independent samples or Mann-Whitney U test. Results Chest wall volume increased significantly with NIV, mean volume=0.43 (SD=0.16)L versus 0.57 (SD=0.19)L (p=0.04). No significant changes were observed for the pulmonary rib cage, abdominal rib cage, or abdominal contribution. The index of the shortening velocity of the diaphragmatic muscle, mean=0.15 (SD=0.05)L/s versus 0.21 (SD=0.05)L/s (p<0.01), and abdominal muscles, mean=0.09 (SD=0.02)L/s versus 0.14 (SD=0.06)L/s (p<0.01), increased during NIV. Comparisons between the supine and sitting positions showed similar changes in chest wall motion in both groups. However, the ALS patients presented a significantly lower contribution of the abdomen in the supine position compared with the controls, mean=56 (SD=13) versus 69 (SD=10) (p=0.02). Conclusions NIV improved chest wall volumes without changing the contribution of the chest wall compartment in ALS patients. In the supine position, ALS patients had a lower contribution of the abdomen, which may indicate early diaphragmatic dysfunction.

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.

Breathing exercises: influence on breathing patterns and thoracoabdominal motion in healthy subjects / Exercícios respiratórios: influência sobre o padrão respiratório e o movimento toracoabdominal em indivíduos saudáveis

BACKGROUND: The mechanisms underlying breathing exercises have not been fully elucidated. OBJECTIVES: To evaluate the impact of four on breathing exercises (diaphragmatic breathing, inspiratory sighs, sustained maximal inspiration and intercostal exercise) the on breathing pattern and thoracoabdominal motion in healthy subjects. METHOD: Fifteen subjects of both sexes, aged 23±1.5 years old and with normal pulmonary function tests, participated in the study. The subjects were evaluated using the optoelectronic plethysmography system in a supine position with a trunk inclination of 45° during quiet breathing and the breathing exercises. The order of the breathing exercises was randomized. Statistical analysis was performed by the Friedman test and an ANOVA for repeated measures with one factor (breathing exercises), followed by preplanned contrasts and Bonferroni correction. A p<0.005 value was considered significant. RESULTS: All breathing exercises significantly increased the tidal volume of the chest wall (Vcw) and reduced the respiratory rate (RR) in comparison to quiet breathing. The diaphragmatic breathing exercise was responsible for the lowest Vcw, the lowest contribution of the rib cage, and the highest contribution of the abdomen. The sustained maximal inspiration exercise promoted greater reduction in RR compared to the diaphragmatic and intercostal exercises. Inspiratory sighs and intercostal exercises were responsible for the highest values of minute ventilation. Thoracoabdominal asynchrony variables increased significantly during diaphragmatic breathing. CONCLUSIONS: The results showed that the breathing exercises investigated in this study produced modifications in the breathing pattern (e.g., increase in tidal volume and decrease in RR) as well as in thoracoabdominal motion (e.g., increase in abdominal contribution during diaphragmatic breathing), among others. .

CONTEXTUALIZAÇÃO: Os mecanismos envolvidos na execução dos exercícios respiratórios não foram completamente elucidados. OBJETIVOS: Avaliar o impacto de quatro exercícios respiratórios(diafragmático, suspiros inspiratórios, inspiração máxima sustentada e intercostal) sobre o padrão respiratório e o movimento toracoabdominal em indivíduos saudáveis. MÉTODO: Participaram do estudo15 indivíduos de ambos os sexos (23±1,5 anos com prova de função pulmonar normal). Os indivíduos foram avaliados por meio da pletismografia optoeletrônica na posição supina com inclinação de tronco de 45° durante a respiração tranquila e durante a realização dos exercícios respiratórios. A ordem dos exercícios foi randomizada. Os dados foram analisados pelo teste de Friedman e ANOVA para medidas repetidas com um fator (exercícios respiratórios) seguidos de contrastes pré-planejados e correção de Bonferroni, sendo p<0,005 considerado significativo. RESULTADOS: Todos os exercícios respiratórios promoveram aumento significativo do volume corrente da parede torácica (VCpt) e redução da frequência respiratória (f) quando comparados à respiração tranquila. O exercício diafragmático foi responsável pelo menor VCpt, menor contribuição da caixa torácica e maior contribuição do abdômen. A inspiração máxima sustentada promoveu redução significativamente maior da f comparada aos exercícios diafragmático e intercostal. Os exercícios suspiros inspiratórios e intercostal foram responsáveis pelos maiores valores de ventilação minuto. Os índices de assincronia toracoabdominal aumentaram significativamente ...

Predictive equations for respiratory muscle strength according to international and Brazilian guidelines.

BACKGROUND: The maximum static respiratory pressures, namely the maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), reflect the strength of the respiratory muscles. These measures are simple, non-invasive, and have established diagnostic and prognostic value. This study is the first to examine the maximum respiratory pressures within the Brazilian population according to the recommendations proposed by the American Thoracic Society and European Respiratory Society (ATS/ERS) and the Brazilian Thoracic Association (SBPT). OBJECTIVE: To establish reference equations, mean values, and lower limits of normality for MIP and MEP for each age group and sex, as recommended by the ATS/ERS and SBPT. METHOD: We recruited 134 Brazilians living in Belo Horizonte, MG, Brazil, aged 20-89 years, with a normal pulmonary function test and a body mass index within the normal range. We used a digital manometer that operationalized the variable maximum average pressure (MIP/MEP). At least five tests were performed for both MIP and MEP to take into account a possible learning effect. RESULTS: We evaluated 74 women and 60 men. The equations were as follows: MIP=63.27-0.55 (age)+17.96 (gender)+0.58 (weight), r(2) of 34% and MEP= - 61.41+2.29 (age) - 0.03(age(2))+33.72 (gender)+1.40 (waist), r(2) of 49%. CONCLUSION: In clinical practice, these equations could be used to calculate the predicted values of MIP and MEP for the Brazilian population.

Predictive equations for respiratory muscle strength according to international and Brazilian guidelines / Equações de predição para a força muscular respiratória segundo diretrizes internacionais e brasileiras

Background: The maximum static respiratory pressures, namely the maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), reflect the strength of the respiratory muscles. These measures are simple, non-invasive, and have established diagnostic and prognostic value. This study is the first to examine the maximum respiratory pressures within the Brazilian population according to the recommendations proposed by the American Thoracic Society and European Respiratory Society (ATS/ERS) and the Brazilian Thoracic Association (SBPT). Objective: To establish reference equations, mean values, and lower limits of normality for MIP and MEP for each age group and sex, as recommended by the ATS/ERS and SBPT. Method: We recruited 134 Brazilians living in Belo Horizonte, MG, Brazil, aged 20-89 years, with a normal pulmonary function test and a body mass index within the normal range. We used a digital manometer that operationalized the variable maximum average pressure (MIP/MEP). At least five tests were performed for both MIP and MEP to take into account a possible learning effect. Results: We evaluated 74 women and 60 men. The equations were as follows: MIP=63.27-0.55 (age)+17.96 (gender)+0.58 (weight), r2 of 34% and MEP= - 61.41+2.29 (age) - 0.03(age2)+33.72 (gender)+1.40 (waist), r2 of 49%. Conclusion: In clinical practice, these equations could be used to calculate the predicted values of MIP and MEP for the Brazilian population. .

Contextualização: A medida das pressões respiratórias estáticas máximas (pressão inspiratória (PImáx) e pressão expiratória máxima (PEmáx)) refletem a força dos músculos respiratórios. Essas medidas são simples, não invasivas e têm valores diagnóstico e prognóstico estabelecidos. Este é o primeiro estudo que avaliou pressões respiratórias máximas com a população brasileira realizado de acordo com as recomendações propostas pela American Thoracic Society e European Respiratory Society (ATS/ERS) e pela Sociedade Brasileira de Pneumologia e Tisiologia (SBPT). Objetivo: Estabelecer equações de referência, valores médios e limites inferiores de normalidade para a PImáx e a PEmáx para cada faixa etária e gênero, conforme as recomendações da ATS/ERS e da SBPT. Método: Foram recrutados 134 brasileiros residentes em Belo Horizonte, MG, Brazil, com idade entre 20-89 anos, com prova de função pulmonar e índice de massa corporal dentro da normalidade. Foi utilizado um manovacuômetro digital que operacionalizou a variável pressão média máxima. Para a PImáx e a PEmáx, foram realizadas, pelo menos, cinco manobras, considerando o efeito aprendizado. Resultados: Foram avaliados 74 mulheres e 60 homens. As equações propostas foram: PImáx=63,27-0,55 (idade)+17,96 (sexo)+0,58 (peso), r2=34% e PEmáx=-61,41+2,29 (idade)-0,03 (idade2)+33,72 (sexo)+1,40 (cintura), r2=49%. Conclusão: As equações resultantes deste estudo poderão ser utilizadas na prática clínica para cálculo de valores preditos para PImáx e PEmáx na população brasileira. .

Functional outcomes in patients with chronic obstructive pulmonary disease: a multivariate analysis.

BACKGROUND: Multiple factors can influence the severity of chronic obstructive pulmonary disease (COPD) and the functioning of patients with COPD, such as personal characteristics and systemic manifestations. OBJECTIVE: To evaluate the different factors that can influence the activity and psychosocial impact domains of the Saint George's Respiratory Questionnaire (SGRQ) in COPD patients. METHOD: Participants, recruited in a university-based hospital, responded to the SGRQ, and in addition, personal, anthropometric, and clinical data were collected. The study was approved by the Institutional Ethics Committee. Data were analyzed using multiple linear regression models, with the SGRQ activity and psychosocial impact scores as outcome variables, and 10 explanatory variables (age, gender, forced expiratory volume in the first second - FEV1, smoking load, body mass index, oxygen therapy, associated diseases, regular physical activity, participation in a formal rehabilitation program, and SGRQ symptoms score) were considered. RESULTS: The best regression model for predicting the SGRQ activity score (r2=0.477) included gender, FEV1, and SGRQ symptoms. In contrast, the predictive model with the highest proportion of explained variance in psychosocial impact score (r2=0.426) included the variables gender, oxygen therapy, and SGRQ symptoms. CONCLUSIONS: The results indicate that the outcomes, while based on functioning parameters in COPD patients, could be partly explained by the personal and clinical factors analyzed, especially by the symptoms assessed by the SGRQ. Thus, it appears that the health conditions of these patients cannot be described by isolated variables, including pulmonary function parameters.

Measurement properties of the incremental shuttle walk test. a systematic review.

Background: The incremental shuttle walk test (ISWT) was developed > 20 years ago and has been used to assess peak exercise capacity in a variety of chronic diseases. The aim of this systematic review is to describe the measurement properties of the ISWT in a clinical population.Methods: Of 800 articles identified by electronic and hand searches, 35 were included. Twenty-one articles included data on the validity of the ISWT, 18 on the reliability, four on the responsiveness,and four on the interpretability.Results: Most of the studies were conducted in patients with COPD (n = 13) or cardiac disease(n = 8). For criterion validity, comparisons between distance covered during the ISWT and peak oxygen consumption reported correlations ranging from 0.67 to 0.95 ( P <.01). Intraclass correlation coefficients for test-retest reliability ranged from 0.76 to 0.99. The ISWT was shown to be responsive to pulmonary rehabilitation and bronchodilator administration. The minimal clinically important difference (MCID) in patients with COPD was 48 m. Predictive equations for the distance in the ISWT are available for healthy individuals.Conclusions: The ISWT can be considered a valid and reliable test to assess maximal exercise capacity in individuals with chronic respiratory diseases. The ISWT has been shown to be responsive to pulmonary rehabilitation and bronchodilator use in individuals with COPD, cystic fibrosis,and asthma. Further studies examining responsiveness and the MCID of the ISWT in patients with conditions other than lung diseases are required for the interpretation of interventions in other populations.