Objective: To determine whether inspiratory muscle training can increase strength and endurance of these muscles in quadriplegic patients. Methods: Eight quadriplegic patients (7 males and 1 female) with injury to the lower cervical spine (segments C4-C7) were submitted to inspiratory muscle training with a threshold inspiratory muscle trainer adjusted to 30% of MIP. The training sessions were carried out with the patients in a sitting position, 5 days a week for 8 weeks. Endurance time, MIP, MEP and FVC were determined at baseline, week 4 and week 8. Results: In comparison with the mean baseline value, there was an increase in MIP, measured in the sitting position, at weeks 4 and 8 (−83.0 ± 18.9 cmH2O vs. −104.0 ± 19.4 cmH2O and −111.3 ± 22.7 cmH2O). There was an increase in MEP, also in the sitting position, at week 4 (from 36.8 ± 8.1 to 42.6 ± 8.8 cmH2O). There was an improvement in FVC at week 4 (from 2.1 ± 0.8 to 2.5 ± 0.6 L, representing an increase of 24 ± 22%). Although there was an increase in endurance (sitting) at week 8, the difference was not significant in comparison with the baseline value (29.8 ± 21.0 vs. 35.9 ± 15.5 min, an increase of 173 ± 233%). Conclusions: Quadriplegic patients can benefit from training at low loads (30% of MIP), which can improve inspiratory muscle strength, FVC and expiratory muscle performance.

Keywords: Respiratory mechanics; Quadriplegia; Breathing exercises.

Objective: The aim of the present study was to evaluate the effects that inspiratory muscle training (IMT) and respiratory exercises have on muscle strength, peak expiratory flow (PEF) and severity variables in children with asthma. Methods: This was a randomized analytical study involving 50 children with asthma allocated to one of two groups: an IMT group, comprising 25 children submitted to IMT via an asthma education and treatment program; and a control group, comprising 25 children who were submitted only to monthly medical visits and education on asthma. The IMT was performed using a pressure threshold load of 40% of maximal inspiratory pressure (MIP). The results were evaluated using analysis of variance, the chi-square test and Fisher's exact test, values of p > 0.05 being considered significant. Results: In the comparative analysis, pre- and post-intervention values of MIP, maximal expiratory pressure (MEP) and PEF increased significantly in the IMT group: MIP from −48.32 ± 5.706 to −109.92 ± 18.041 (p < 0.0001); MEP from 50.64 ± 6.55 to 82.04 ± 17.006 (p < 0.0001); and PEF from 173.6 ± 50.817 to 312 ± 54.848 (p < 0.0001). In the control group, however, there were no significant differences between the two time points in terms of MIP or MEP, although PEF increased from 188 ± 43.97 to 208.80 ± 44.283 (p < 0.0001). There was a significant improvement in the severity variables in the IMT group (p < 0.0001). Conclusions: Programs involving IMT and respiratory exercises can increase mechanical efficiency of the respiratory muscles, as well as improving PEF and severity variables.

Keywords: Breathing exercises; Asthma/therapy; Asthma/rehabilitation.

Inspiratory muscle training (IMT) has been described as one of the components of the treatment of chronic lung conditions such as obstructive and restrictive lung diseases. Although the number of studies showing results of IMT in patients with interstitial lung disease (ILD) is scarce when compared with studies in patients with COPD, evidence points to benefits of IMT in this population. This scoping review aimed to explore the role and the rationale of IMT in patients with ILD and to gather recent evidence on the effects of IMT in this population. The studies included in this review showed improvements in respiratory muscle function, quality of life, exercise capacity and dyspnea after ILD patients participated in programs that included stand-alone IMT or combined with pulmonary rehabilitation. There is still a gap in the literature to allow a clear conclusion on the indications of IMT as part of ILD treatment because of poor research design and small numbers of participants. Therefore, although IMT seems to have a positive effect in patients with ILD, current evidence prevents us from drawing a definite conclusion. Further studies need to be conducted using better research methodology to demonstrate and confirm the positive effects of IMT.

Keywords: Respiratory muscles; Lung diseases, interstitial; Rehabilitation.

Objective: Respiratory muscle weakness is a functional repercussion of chronic lung disease (CLD). The objective of this study was to assess the effects of home-based respiratory muscle training (RMT) in children and adolescents with CLD or neuromuscular disease (NMD). Methods: This was a quasi-experimental study involving children and adolescents with CLD or NMD. Before and after 6 months of home-based RMT, we measured respiratory muscle strength (MIP and MEP), PEF, and peak cough flow (PCF). We made statistical comparisons between the pre-RMT and post-RMT values, as well as evaluating the correlation between the duration and effect of RMT. Results: The study included 29 patients, with a mean age of 12 years (range, 5-17 years), of whom 18 (62.1%) were male. The CLD group comprised 11 patients (37.9%), and the NMD group comprised 18 (62.1%). The mean duration of the RMT was 60 weeks (range, 46-90 weeks) in the CLD group and 39 weeks (range, 24-89 weeks) in the NMD group. In comparison with the pre-RMT values, the post-RMT values for MIP and MEP were significantly higher in both groups, whereas those for PEF and PCF were significantly higher only in the NMD group. We found no correlation between the duration and the effect of RMT. Conclusions: Home-based RMT appears to be an effective strategy for increasing respiratory muscle strength in children and adolescents with CLD or NMD, although it increased the ability to cough effectively only in those with NMD.

Keywords: Breathing exercises; Cystic fibrosis; Bronchiolitis obliterans; Neuromuscular diseases; Cough.

Objectives: Several equations for calculating maximal inspiratory pressure (MIP) have been validated for the Brazilian population; however, none exist for maximal dynamic inspiratory muscle pressure (S-Index). Methods: This cross-sectional study was conducted at two centers following approval by the institutional ethics committee. Healthy Brazilian adults were sequentially randomized to assess either the MIP or S-Index. Pulmonary function (spirometry), peripheral muscle strength (handgrip strength of the dominant upper limb - HGdUL), and physical activity level (IPAQ) were also evaluated. The S-Index and MIP values were reported as absolute values and compared using the Wilcoxon paired test. Multiple linear regression was used to develop reference equations. Lower limits of normality (LLNs) were stratified by sex and age using Z-scores, providing cut-off points to define inspiratory muscle weakness via the S-Index Deviation Score (SDS). Results: The final sample comprised 214 eutrophic volunteers, 50% men, with a mean age of 43.1 ± 15.0 years. The median MIP was significantly higher than the median S-Index (97.2 [96.7-112.0] vs. 92.5 [80.0-105.0] cmH2O; p<0.001). The predicted equation for the S-Index, which used age, sex, and HGdUL as predictors, was: S-Index = 69.72 + 10.765×sex (men = 1; women = 0) - 0.211×age + 0.797×HGdUL. Additionally, the LLNs and cut-off points for ventilatory muscle weakness by sex and age group were established. Conclusions: This study provides the first reference values for the S-Index in healthy, eutrophic Brazilian adults, including LLNs and cut-off points for diagnosing ventilatory muscle weakness.

Keywords: Respiratory muscle strength; S-Index; Respiratory muscle assessment.

Impairment of (inspiratory and expiratory) respiratory muscles is a common clinical finding, not only in patients with neuromuscular disease but also in patients with primary disease of the lung parenchyma or airways. Although such impairment is common, its recognition is usually delayed because its signs and symptoms are nonspecific and late. This delayed recognition, or even the lack thereof, occurs because the diagnostic tests used in the assessment of respiratory muscle strength are not widely known and available. There are various methods of assessing respiratory muscle strength during the inspiratory and expiratory phases. These methods are divided into two categories: volitional tests (which require patient understanding and cooperation); and non-volitional tests. Volitional tests, such as those that measure maximal inspiratory and expiratory pressures, are the most commonly used because they are readily available. Non-volitional tests depend on magnetic stimulation of the phrenic nerve accompanied by the measurement of inspiratory mouth pressure, inspiratory esophageal pressure, or inspiratory transdiaphragmatic pressure. Another method that has come to be widely used is ultrasound imaging of the diaphragm. We believe that pulmonologists involved in the care of patients with respiratory diseases should be familiar with the tests used in order to assess respiratory muscle function.Therefore, the aim of the present article is to describe the advantages, disadvantages, procedures, and clinical applicability of the main tests used in the assessment of respiratory muscle strength.

Keywords: Respiratory muscles; Muscle weakness; Diaphragm; Respiratory function tests; Diagnostic tests, routine.

The aim of the study was to evaluate the performance of sniff nasal inspiratory pressure (SNIP) and MIP in individuals with spinal cord injury. We evaluated 26 patients with spinal cord injury. Mean FVC in those with tetraplegia was 52 ± 19% of predicted, compared with 78 ± 23% of predicted in those with paraplegia (p < 0.05). In contrast, the percentage of predicted SNIP was lower in those with tetraplegia than in those with paraplegia (p < 0.05). In all participants, SNIP correlated significantly with the level of the injury (r = 0.489; 95% CI: 0.125‑0.737). The impact that the greater discriminatory power of SNIP has on the diagnosis of impaired pulmonary function in spinal cord-injured patients should be investigated further.

Keywords: Spinal cord injuries; Respiratory function tests; Respiratory muscles; respiratory paralysis.

Objective: To evaluate the responsiveness of the six-minute step test (6MST) to an aerobic physical training program (PTP) and to determine the efficacy of the PTP regarding spirometric variables during the 6MST, as well as physical performance, sensation of dyspnea, and SpO2 during the 6MST and the six-minute walk test (6MWT), in patients with COPD. Methods: This was a controlled, prospective randomized study involving patients clinically diagnosed with COPD, with an FEV1/FVC ratio < 70%, and having been clinically stable in the last two months. The patients were randomized to undergo a PTP on a treadmill, three times a week, for six weeks (PTP group) or not (control group). Histories were taken from all of the patients, who received regular respiratory therapy during the study period, undergoing physical examination and spirometry before and after bronchodilator use; incremental symptom-limited cardiopulmonary exercise testing; the 6MST; and the 6MWT. Results: Of the 36 patients that completed the study, 21 and 15 were in the PTP and control groups, respectively. In the PTP group, there was a significant increase in the number of steps climbed during the 6MST and in the six-minute walk distance (in m and % of predicted), as well as a significant decrease in the sensation of dyspnea during the 6MWT. Conclusions: The 6MST showed responsiveness to the PTP. However, the 6MWT appears to be more responsive to the PTP proposed.

Keywords: Exercise test; Exercise; Pulmonary disease, chronic obstructive.

Background: Patients with chronic obstructive pulmonary disease usually present intolerance to physical exertion due to ventilatory limitation. L-carnitine has been used to enhance aerobic capacity in patients with chronic diseases, but no study seems to be available for this patient population. Objective: To evaluate the influence of L-carnitine supplementation (2 g/day) in chronic obstructive pulmonary disease patients undergoing physical training three times a week for six weeks. Method: Patients (mean age 69 ± 7 years, n = 30) with stable chronic obstructive pulmonary disease and < 65% of predicted forced expiratory volume in 1 second (FEV1) were separated into three groups of 10 patients each. Group 1 (G1, n = 10) received physical training and L-carnitine (2 g/day), group 2 (G2, n = 10) received physical training and placebo, and group 3 (G3, n = 10) received only L-carnitine (2 g/day). Spirometry and a 6-minute walking distance test were performed before and after intervention. Plasma levels of free carnitine were measured at the beginning and end of the study. Results: A significant increase in walking distance was found only in G1 and G2 (421 ± 100 to 508 ± 80.7 and 496 ± 78.7 to 526 ± 64.3 respectively). In addition, heart rates during physical training sessions were found to be significantly lower in G1 when compared to G2. There were no significant changes in spirometric variables, oxygen saturation or dyspnea in any group. Plasma levels of free L-carnitine were found to increase only in G3 (59.2 ± 13.8 to 102.3 ± 15.3 mmol/L). Conclusion: Oral L-carnitine supplementation combined with physical training may improve tolerance to physical exertion in chronic obstructive pulmonary disease patients.

Keywords: Chronic obstructive pulmonary disease. Carnitine/therapeutic use. Spirometry/methods. Exercise. Walking.

Objective: To evaluate the electromyographic activity (EA) of sternocleidomastoid (SCM) and scalene muscles during and after the use of expiratory positive airway pressure (EPAP) in patients with COPD. Methods: This was a clinical single-blind trial involving 13 healthy subjects as controls and 12 patients with stable COPD. At baseline, we determined EA during spontaneous respiration, lung function parameters, and respiratory muscle strength. Subsequently, EPAP at 15 cmH2O was applied by means of a face mask for 25 min, during which the EA of the SCM and scalene muscles was recorded every 5 min. A final record was obtained 10 min after the mask removal. Results: We found that the behavior of the EA of SCM and scalene muscles was comparable between the controls and the COPD patients (p = 0.716 and p = 0.789, respectively). However, during the use of EPAP, both muscles showed a trend toward an increase in the EA. In addition, there was a significant decrease in the EA of the SCM between the baseline and final measurements (p = 0.034). Conclusions: The use of EPAP promoted a significant reduction in the EA of the SCM in the controls and in the patients with stable COPD. However, this did not occur regarding the EA of the scalene muscle.

Keywords: Electromyography; Respiratory muscles; Pulmonary disease, chronic obstructive; Positive-pressure respiration.

Objective: To investigate the efficacy of upper limb exercise training (ULExT) in improving the performance of activities of daily living (ADL) that involve the upper limbs (UL) in patients with COPD. Methods: The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were used in this systematic review. PubMed and EBSCOhost databases were searched to identify randomized controlled trials involving adults with COPD who underwent ULExT, compared with those who underwent other types of exercise or no exercise, in order to assess the performance of ADL that involve the UL. The methodological quality of the selected studies was assessed using the Physiotherapy Evidence Database scale. Results: Five studies, with a total sample of 173 subjects, met the inclusion criteria. The results of the selected studies showed that ULExT is safe and can significantly improve the performance of ADL that involve the UL in patients with COPD. However, there were inconsistencies in the results, especially regarding the perception of symptoms during ADL. The small number of studies included and their methodological quality do not allow for firm conclusions. Conclusions: The findings of this review revealed that ULExT is a safe therapeutic approach and can improve the performance of ADL that involve the UL in patients with COPD, but the results are unclear. Further investigation through well-designed randomized trials is warranted to determine the effectiveness of ULExT in improving the performance of ADL that involve the UL in patients with COPD.

Keywords: Upper extremity; Pulmonary disease, chronic obstructive; Activities of daily living, Exercise therapy.

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.

Keywords: Pulmonary disease, chronic obstructive; Respiratory function tests; Respiratory muscles.

Objective: To evaluate pulmonary function and respiratory muscle strength in chronic renal failure patients, correlating these variables with hemodialysis-related weight fluctuation; to study the correlation between the duration of hemodialysis and potential respiratory alterations. Methods: Seventeen patients (median age, 47 years; interquartile range, 41-52 years), submitted to three weekly hemodialysis sessions for a median of 27 months (interquartile range, 14-55) were evaluated. Twelve of the patients were male. The patients underwent spirometry. Maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) were measured prior to and after the first hemodialysis session of the week. Body weight was quantified prior to and after each of the three weekly sessions. Results: Before the first hemodialysis session of the week, 8 patients presented mild restrictive defect, which normalized after the session in 2 of those patients. After dialysis, there was a significant increase in forced vital capacity (p = 0.02) and a significant decrease in body weight (p = 0.0001). Weight fluctuation over 3 days without hemodialysis tended to correlate with the variation in forced vital capacity in the first weekly session (r = 0.47; p = 0.055). Duration of hemodialysis correlated with predialysis MIP (r = −0.3; p = 0.03) and MEP (r = −0.63; p = 0.006). Conclusions: More pronounced weight gain in the interdialytic period is associated with worsening of lung function, which is almost fully reversible by hemodialysis. In addition, longer duration of hemodialysis is associated with decreased respiratory muscle strength.

Keywords: Spirometry; Respiratory muscles/physiopathology; Kidney failure, chronic; Renal dialysis.

Objective: To evaluate respiratory muscle strength and six-minute walk test (6MWT) variables in patients with uncontrolled severe asthma (UCSA). Methods: This was a cross-sectional study involving UCSA patients followed at a university hospital. The patients underwent 6MWT, spirometry, and measurements of respiratory muscle strength, as well as completing the Asthma Control Test (ACT). The Mann-Whitney test was used in order to analyze 6MWT variables, whereas the Kruskal-Wallis test was used to determine whether there was an association between the use of oral corticosteroids and respiratory muscle strength. Results: We included 25 patients. Mean FEV1 was 58.8  21.8% of predicted, and mean ACT score was 14.0  3.9 points. No significant difference was found between the median six-minute walk distance recorded for the UCSA patients and that predicted for healthy Brazilians (512 m and 534 m, respectively; p = 0.14). During the 6MWT, there was no significant drop in SpO2. Mean MIP and MEP were normal (72.9  15.2% and 67.6  22.2%, respectively). Comparing the patients treated with at least four courses of oral corticosteroids per year and those treated with three or fewer, we found no significant differences in MIP (p = 0.15) or MEP (p = 0.45). Conclusions: Our findings suggest that UCSA patients are similar to normal subjects in terms of 6MWT variables and respiratory muscle strength. The use of oral corticosteroids has no apparent impact on respiratory muscle strength.

Objective: To compare equations for predicting peak quadriceps femoris (QF) muscle force; to determine the agreement among the equations in identifying QF muscle weakness in COPD patients; and to assess the differences in characteristics among the groups of patients classified as having or not having QF muscle weakness by each equation. Methods: Fifty-six COPD patients underwent assessment of peak QF muscle force by dynamometry (maximal voluntary isometric contraction of knee extension). Predicted values were calculated with three equations: an age-height-weight-gender equation (Eq-AHWG); an age-weight-gender equation (Eq-AWG); and an age-fat-free mass-gender equation (Eq-AFFMG). Results: Comparison of the percentage of predicted values obtained with the three equations showed that the Eq-AHWG gave higher values than did the Eq-AWG and Eq-AFFMG, with no difference between the last two. The Eq-AHWG showed moderate agreement with the Eq-AWG and Eq-AFFMG, whereas the last two also showed moderate, albeit lower, agreement with each other. In the sample as a whole, QF muscle weakness (< 80% of predicted) was identified by the Eq-AHWG, Eq-AWG, and Eq-AFFMG in 59%, 68%, and 70% of the patients, respectively (p > 0.05). Age, fat-free mass, and body mass index are characteristics that differentiate between patients with and without QF muscle weakness. Conclusions: The three equations were statistically equivalent in classifying COPD patients as having or not having QF muscle weakness. However, the Eq-AHWG gave higher peak force values than did the Eq-AWG and the Eq-AFFMG, as well as showing greater agreement with the other equations.

Keywords: Pulmonary disease, chronic obstructive; Muscle strength; Quadriceps muscle; Reference values.

Objective: To evaluate diaphragmatic mobility in relation to lung function, respiratory muscle strength, dyspnea, and physical activity in daily life (PADL) in patients with COPD. Methods: We included 25 patients with COPD, classified according to the Global Initiative for Chronic Obstructive Lung Disease criteria, and 25 healthy individuals. For all of the participants, the following were evaluated: anthropometric variables, spirometric parameters, respiratory muscle strength, diaphragmatic mobility (by X-ray), PADL, and the perception of dyspnea. Results: In the COPD group, diaphragmatic mobility was found to correlate with lung function variables, inspiratory muscle strength, and the perception of dyspnea, whereas it did not correlate with expiratory muscle strength or PADL. Conclusions: In patients with COPD, diaphragmatic mobility seems to be associated with airway obstruction and lung hyperinflation, as well as with ventilatory capacity and the perception of dyspnea, although not with PADL.

Keywords: Pulmonary disease, chronic obstructive; Diaphragm; Spirometry; Dyspnea; Maximal respiratory pressures.

The objective of this study was to assess the efficacy of exercise training by means of a rehabilitative walking protocol. Twenty patients with COPD staged as III/IV according to the Global Initiative for Chronic Obstructive Lung Disease were included. Patients were evaluated at baseline and at the end of the exercise program regarding oxygen desaturation, sensation of dyspnea/fatigue, quality of life and six-minute walk distance. The comparison between the six-minute walk distance prior to and after training proved the efficacy of the protocol, which also resulted in a decrease in oxygen desaturation and in the sensation of dyspnea. This protocol can be easily put into practice.

Keywords: Activities of daily living; Pulmonary disease, chronic obstructive; Rehabilitation; Exercise therapy; Exercise test.

Bronchoscopy is an important procedure to examine the airways. It is traditionally taught by having trainees perform it in humans. This carries risks, albeit rarely, and causes stress to trainees. The objective of this study was to review bronchoscopy simulators, as well as their use in and impact on medical education, presenting perspectives on the use of simulators in the post-pandemic world. This review was based on articles published in English in 2000-2021 and retrieved from any of the following databases: MEDLINE (PubMed), Embase, SciELO, and Google Scholar. Bronchoscopy simulators have improved markedly over time, allowing the teaching/learning process to take place in a risk-free environment. Bronchoscopy simulation training is an interesting option for the evaluation of the airways, especially in the coming years, with the COVID-19 pandemic highlighting the need for continuing medical education.

Keywords: Bronchoscopy; Learning; Teaching; Students; Coronavirus.