Relationship between inspiratory muscle strength and balance in women: A cross-sectional study.

BACKGROUND: There is scarce evidence on changes at the functional level associated with the respiratory area in women. This study aims to analyse the relationship between inspiratory muscle strength and balance in women. MATERIAL AND METHODS: In this cross-sectional observational study, the sample consisted of groups according to the results obtained in the balance test. Inspiratory muscle weakness was defined as maximum inspiratory pressure (MIP) ≤ 80% of the predictive value. MIP was carried out using through a mouthpiece, with an electronic manometer. Logistic regression model was used to examine if MIP predicts balance. RESULTS: 159 women participated in the study. Approximately 20% of them achieved balance ≤ 2 seconds and 18% presented MIP≤80%. MIP was associated with the time achieved in the one-leg support test. Subjects with MIP ≤ 80% of the predictive value show 3 times more risk of having a lower performance in the balance test (OR = 3.26). CONCLUSIONS: Inspiratory muscle weakness is associated with deficient balance in this sample. It shows the need for multidimensional assessment and rehabilitation strategies for patients identified as having MIP weakness and/or balance disorders.

A Prospective Study of 73 Patients to Compare Forward Head Angle, Forward Shoulder Angle, Maximal Inspiratory Pressure, and Self-Reported Breathing-Related Symptoms Before and After Open-Heart Surgery.

BACKGROUND Patients who undergo open-heart surgery often experience widespread musculoskeletal and pulmonary complications. These can interfere with their functioning, resulting in soft tissue changes, worsening postural changes, and poor respiratory performance. Therefore, the prospective study aimed to compare forward head angle (FHA) and forward shoulder angle (FSA), maximal inspiratory pressure (MIP), and self-reported breathing dysfunction before and after open-heart surgery. MATERIAL AND METHODS In a prospective observational study of 106 patients, men and women scheduled for open-heart surgery were enrolled. Prior to surgery and before discharge from the hospital, all patients were required to assess FHA and FSA using 2-dimensional motion analysis software, MIP using a respiratory pressure meter, and breathing dysfunction using the 25-item Self Evaluation of Breathing Questionnaire (SEBQ). Paired t test was used to compare differences between before and after surgery. To evaluate associations, logistic regression analysis was performed. RESULTS Of the 106 patients recruited, 73 completed the study. FHA (-Δ6.55±4.77, P.

Inspiratory Muscle Training Improves Maximal Inspiratory Pressure Without Increasing Performance in Elite Swimmers.

PURPOSE: To analyze the effect of inspiratory muscle training (IMT) on the maximal inspiratory mouth pressure (MIP) and performance of elite swimmers. METHODS: Eight participants performed a 3000-m swimming test (T-3000), followed by blood lactate measurements at 1 and 5 minutes postexercise.. The testing protocol was carried out before and after 6 weeks of IMT, in which a high-volume IMT group (HV-IMT) (n = 4) performed IMT twice a day-in the morning in a seated position and in the afternoon in a concurrent session of IMT and core muscle training. Also, a low-volume IMT group (LV-IMT) (n = 4) performed IMT in the morning session only. RESULTS: After the intervention, both groups improved their MIP, HV-IMT (132.75 [27.42] to 156.75 [21.88] cmH2O; P = .010; d = 0.967) and LV-IMT (149.25 [22.82] to 171.50 [23.74] cmH2O; P = .013; d = 0.955), without a significant difference between groups (P = .855). Regarding swimming performance, there were no changes between groups in the T-3000 (P = .472) or lactate removal rate (P = .104). CONCLUSION: IMT increased inspiratory muscle strength in elite swimmers, but there was no association or meaningful impact on swimming performance.

Validation of the Single Breath Count Test for Assessment of Inspiratory Muscle Strength in Healthy Subjects and People with Neuromuscular Disorders.

OBJECTIVE: This study aimed to validate the single breath count test (SBCT) against volitional measures of respiratory muscle function in healthy subjects and people with neuromuscular disorders (NMD; n = 100 per group). METHODS: Testing comprised upright and supine SBCT, forced vital capacity (FVC), maximum inspiratory pressure (MIP), and sniff nasal inspiratory pressure (SNIP). Predictability of FVC by SBCT was assessed using logarithmic regression analysis. Receiver operating characteristics curves were used to identify SBCT thresholds for lung restriction (FVC < 80% predicted), inspiratory muscle weakness (MIP < 60 cmH2O), and indication for non-invasive ventilation (NIV) in NMD patients. RESULTS: In both groups, SBCT showed moderate correlation with FVC. In patients, SBCT values were also correlated with MIP and SNIP. Strength of correlations was similar with supine and upright SBCT which accounted for 23.7% of FVC variance in healthy individuals (44.5% in patients). Predictive thresholds of upright SBCT were < 27 for MIP < 60 cmH2O (sensitivity 0.61/specificity 0.86), <39 for NIV indication (0.92/0.46), and <41 for FVC < 80% predicted (0.89/0.62). CONCLUSION: The SBCT is positively correlated with spirometry. It predicts both lung restriction and NIV indication in NMD patients. The SBCT allows for remote monitoring and may substitute for spirometry/manometry if appropriate devices are unavailable.

New reference values for maximum respiratory pressures in healthy Brazilian children following guidelines recommendations: A regional study.

OBJECTIVE: To determine reference values for maximum static respiratory pressures in healthy children from a Brazilian region, following recommendations of the European Respiratory Society (ERS) and the Brazilian Society of Pneumology and Tisiology (SBPT). METHODS: A cross-sectional observational study was conducted with healthy children (6 to 11 years) of both sexes. The maximum inspiratory and expiratory pressures (PImax and PEmax, respectively) were measured using a digital manometer. Each child performed a minimum of three and a maximum of five maneuvers; three acceptable and reproducible maneuvers were considered for analysis. Minimum time for each maneuver was 1.5 seconds, with a one-second plateau, and one minute of rest between them. A stepwise multiple linear regression analysis was conducted for PImax and PEmax, considering correlations between independent variables: age, weight, and sex. RESULTS: We included 121 children (62 girls [51%]). Boys reached higher values for maximum respiratory pressures than girls. Respiratory pressures increased with age showing moderate effect sizes (PImax: f = 0.36; PEmax: f = 0.30) between the stratified age groups (6-7, 8-9, and 10-11 years). Age and sex were included in the PImax equation (PImax = 24.630 + 7.044 x age (years) + 13.161 x sex; R2 = 0.189). PEmax equations were built considering age for girls and weight for boys [PEmax (girls) = 55.623 + 4.698 x age (years) and PEmax (boys) = 82.617 + 0.612 x weight (kg); R2 = 0.068]. CONCLUSIONS: This study determined new reference equations for maximal respiratory pressures in healthy Brazilian children, following ERS and SBPT recommendations.

The respiratory effects of a Pilates method protocol: Randomized clinical trial.

OBJECTIVES: To evaluate the respiratory effects of a Pilates method (PM) protocol in adult women. DESIGN: Single-blind randomized controlled trial. SETTINGS: Healthy women were randomized into two groups using the Random.org online tool: a Pilates group (PG) (n = 33) and a control group (CG) (n = 29). PARTICIPANTS: Sixty-two healthy women, aged 18-44 years, sedentary or irregularly active B (as defined by the international physical activity questionnaire [IPAQ]). The intervention consisted of 16 sessions of PM. protocol twice a week for the PG. The CG without intervention. MAIN OUTCOMES MEASURES: The variables evaluated were maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), peak expiratory flow (PEF), tidal volume (TV), respiratory frequency (RF), minute volume (MV), and slow vital capacity (SVC). RESULTS: The results showed significant evidence of the beneficial respiratory effects of the PM protocol when the PG was compared with the CG: increased MIP (p = 0.001), and a significant increase in TV (p = 0,047). CONCLUSION: The PM protocol used in this study may be effective for respiratory muscle strength because it improved MIP and TV. CLINICAL TRIAL REGISTRATION: https://ensaiosclinicos.gov.br/rg/RBR-5b6wc3.

Comparison of international and Japanese predictive equations for maximal respiratory mouth pressures.

Respiratory muscle weakness has attracted attention because sarcopenia and respiratory muscle dysfunction may play a key role in the development of respiratory failure. To evaluate respiratory muscle strength appropriately, individual factors such as sex, age, body size, and ethnicity should be considered. This study aimed to compare equations available in Japan and other countries for predicting respiratory muscle strength. We tested 21 equations for maximal inspiratory pressure (MIP) and 17 for maximal expiratory pressure (MEP) for each sex (76 equations in total) in 159 normal, healthy subjects. We observed wide variations in the overall agreement among the MIP and MEP equations. Some equations showed a proper normal distribution, with median values of almost 100%, and the Japanese equations released in 1997 generally showed the best distributions of both %MIP and %MEP. We can conclude that it is better to use Japanese equations when evaluating respiratory muscle strength in Japanese subjects.

[Maximum expiratory pressure is a good predictor of the incidence of the frailty syndrome in elderly men]. / Pressão expiratória máxima é boa preditora de incidência da síndrome de fragilidade em homens idosos.

This article aims to investigate the association between maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) with the incidence of frailty syndrome (FS), in addition to testing the predictive ability of MIP and MEP to discriminate FS in elderly adults, according to sex. It is a longitudinal study with a five-year follow-up period (2014-2019), carried out with 104 elderly adults registered in the Family Health Strategy of a municipality in Bahia. The incidence of frailty syndrome was diagnosed according to criteria proposed by Fried et al., using data from 2019, after a five-year follow-up. The MIP and MEP were evaluated according to the recommendations of the Brazilian Society of Pulmonology and Phthisiology data in 2014 (baseline data). The total incidence of frailty syndrome was 16.3% (95%CI: 9.2-23.6), with 13.6% (95%CI: 4.56-22.55) in women and 20% (95%CI: 7.85-32.15) in men. The mean values of MIP and MEP were, respectively, 60,8±21,2 cmH2O and 76,7±23,1 cmH2O in women, and 79,5±27,0 cmH2O and 114,7±29,8 cmH2O in men. The frailty syndrome was associated with MEP in elderly adult men (adjusted RR: 0.96; 95%CI: 0.95-0.98; P-value: 0.002), indicating that the increase of 1cmH2O in MEP reduces by 4% the risk of developing the syndrome.

O objetivo deste artigo é investigar a associação entre a Pressão Inspiratória Máxima (PImáx) e Pressão Expiratória Máxima (PEmáx) com a incidência da síndrome de fragilidade (SF), além de testar a capacidade preditiva da PImáx e PEmáx em discriminar a SF em idosos, de acordo com o sexo. Estudo longitudinal com cinco anos de seguimento (2014-2019), realizado com 104 idosos cadastrados na Estratégia Saúde da Família de um município da Bahia. A incidência da síndrome de fragilidade foi diagnosticada de acordo os critérios propostos por Fried et al., utilizando dados de 2019, após cinco anos de seguimento. A PImáx e PEmáx foram avaliadas conforme recomendações da Sociedade Brasileira de Pneumologia e Tisiologia em 2014 (linha de base). A incidência total da SF foi de 16,3% (IC95%: 9,2-23,6), sendo 13,6% (IC95%: 4,56-22,55) no sexo feminino e 20,0% (IC95%: 7,85-32,15) no sexo masculino. Os valores médios da PImáx e PEmáx foram, respectivamente, 60,8±21,2 cmH2O e 76,7±23,1 cmH2O no sexo feminino, e 79,5±27,0 cmH2Oe 114,7±29,8 cmH2O no sexo masculino. A SF esteve associada à PEmáx em idosos do sexo masculino (RR ajustado: 0,96; IC95%: 0,95-0,98; p-valor: 0,002), indicando que o aumento de 1 cmH2O da PEmáx reduz em 4% o risco de desenvolver a síndrome de fragilidade.

Relationships between diaphragm ultrasound, spirometry, and respiratory mouth pressures in children.

Diaphragm ultrasound (DUS) is a noninvasive method of evaluating the diaphragm's structure and function. This study explored the relationships between DUS, spirometry, and respiratory mouth pressures in 10 healthy children (median age: 11 [range: 7-14 years]; 5 females, 5 males). Thickening fraction correlated with maximal inspiratory pressure (MIP) (Spearman's rho [rs] = 0.64, p = 0.05). During quiet breaths, excursion time correlated with MIP (rs = 0.78, p = 0.01) while velocity correlated with maximal expiratory pressure (rs = -0.82, p = 0.01). During deep breaths, MIP correlated with excursion (rs = 0.64, p = 0.05) and time (rs = 0.87, p = 0.01). Excursion time during deep breaths also correlated with forced vital capacity (rs = 0.65, p = 0.04). Our findings suggest that DUS parameters are closely related to spirometry and respiratory mouth pressures in healthy children and further support the use of DUS as a noninvasive method of respiratory assessment.

Standard reference and percentiles of maximum respiratory pressures values of healthy children aged 7-10 years.

OBJECTIVE: This study aims to present standard reference for values of maximum respiratory pressures of healthy schoolchildren, according to gender. METHODS: This is a cross-sectional study involving healthy children aged 7-10 years. Data of body mass and height were evaluated to calculate body mass index (BMI). In addition, forced expiratory volume in 1 second (FEV1) and maximal expiratory pressure values were evaluated according to the American Thoracic Society. The maximal inspiratory pressure (MIP) and data of maximal expiratory pressure (MEP) obtained in the study showed normal distribution and curves were built by the Lambda-Mu-Sigma (LMS) method, as well as the values of MIP and MEP percentiles 3, 10, 25, 50, 75, 90, and 97 for each gender. RESULTS: MIP and MEP data were collected from 399 schoolchildren. All schoolchildren in the sample had adequate FEV1 and BMI. The study showed an increase in respiratory pressure values with age progression. The MIP and MEP values of girls were of 53.4±11.0 and 61.8±12.5cmH2O, respectively, and those of boys were 59.9±13.6 and 69.6±15.7cmH2O, respectively. CONCLUSIONS: Normal curves and percentiles were developed for MIP and MEP values of healthy schoolchildren. The extreme percentiles (3rd and 97th) were determined, and a specific graph was elaborated for each group. These graphs may help clinical follow-up and therapeutic monitoring of different pediatric populations.

Ultrasonography in Assessment of Respiratory Muscles Function: A Systematic Review.

INTRODUCTION: The purpose of this study was to evaluate the potential utility of respiratory muscles ultrasound (US) imaging for assessing respiratory function and identify US variables that best correlate with pulmonary parameters. MATERIALS AND METHODS: A search of 5 databases was conducted. Initially, there was no language, study design, or time frame restrictions. All studies assessing the relationship between pulmonary and US parameters were included. Two reviewers independently extracted and documented data regarding to examined population, age, gender, health condition, methodology, US, and pulmonary function measurements. All studies were qualitative synthesis. RESULTS: A total of 1,272 participants from 31 studies were included. Diaphragm thickness, diaphragm thickening ratio, and diaphragm excursion amplitude were mainly used as US parameters. Forced vital capacity, forced expiratory volume1sec, and maximal inspiratory pressure were mainly used as pulmonary parameters. The relationships between pulmonary and US parameters varied from negligible to strong (depend on examined population and methodology used). Data were not quantitatively synthesis due to high heterogeneity in terms of study design, population examined, and various pulmonary and US parameters. CONCLUSION: A strong relationship between US measurements and pulmonary parameters was demonstrated in some studies but not others. This review confirmed that US measurements can complement spirometry, but the exact role of the US remains to be confirmed. Further studies using standardized methodology are needed to obtain more conclusive evidence on the usefulness of US for assessing respiratory function.

Reproducibility of Maximum Respiratory Pressure Assessment: A Systematic Review and Meta-analysis.

BACKGROUND: Accurate assessment of maximum respiratory pressure is vital when tracking disease progression and devising treatment strategies. Previous studies indicate a learning effect when undertaking maximum respiratory pressure measurements. The extent of this learning effect and methodologies undertaken to mitigate this learning effect have not been investigated systematically. RESEARCH QUESTION: What is the magnitude of improvements in maximum respiratory pressure in response to respiratory muscle warm-up protocols and repeated measures of maximum respiratory pressure in healthy individuals and clinical populations? METHODS: A comprehensive search of electronic databases was undertaken during August 2021 for studies examining the intrarater reliability of maximum inspiratory or expiratory pressure, or both, studies developing a protocol or an intervention to obtain maximum values, and studies analyzing the reliability of repeated maneuvers in a single testing session in healthy individuals and clinical populations. Included articles were analyzed critically using two appraisal tools. Standardized mean differences with 95% CIs were calculated and corrected for the sample size as a measure of the magnitude of change in maximum respiratory pressure outcomes. RESULTS: Of the 1,969 articles retrieved, 32 were included in the meta-analysis. Eighteen studies included healthy individuals and 14 studies included individuals with chronic medical conditions. The overall effect of inspiratory muscle warm-up protocols was higher (effects size [ES], 0.40; 95% CI, 0.17-0.63) in comparison with single testing session studies (ES, 0.20; 95% CI, 0.05-0.35) and studies performing repeated testing sessions of maximum respiratory pressure (ES, 0.14; 95% CI, 0.07-022). INTERPRETATION: Inspiratory muscles warm-up procedures induce higher increases in maximum inspiratory pressure in comparison with single and repeated testing sessions of maximum respiratory pressure in healthy individuals. Warm-up protocols are more effective to obtain the maximum performance of inspiratory muscles in one testing session in comparison with other methods. TRIAL REGISTRY: PROSPERO; No.: CRD42022304591; URL: https://www.crd.york.ac.uk/prospero/.

Randomized Clinical Study of Temporary Transvenous Phrenic Nerve Stimulation in Difficult-to-Wean Patients.

Rationale: Diaphragm dysfunction is frequently observed in critically ill patients with difficult weaning from mechanical ventilation. Objectives: To evaluate the effects of temporary transvenous diaphragm neurostimulation on weaning outcome and maximal inspiratory pressure. Methods: Multicenter, open-label, randomized, controlled study. Patients aged ⩾18 years on invasive mechanical ventilation for ⩾4 days and having failed at least two weaning attempts received temporary transvenous diaphragm neurostimulation using a multielectrode stimulating central venous catheter (bilateral phrenic stimulation) and standard of care (treatment) (n = 57) or standard of care (control) (n = 55). In seven patients, the catheter could not be inserted, and in seven others, pacing therapy could not be delivered; consequently, data were available for 43 patients. The primary outcome was the proportion of patients successfully weaned. Other endpoints were mechanical ventilation duration, 30-day survival, maximal inspiratory pressure, diaphragm-thickening fraction, adverse events, and stimulation-related pain. Measurements and Main Results: The incidences of successful weaning were 82% (treatment) and 74% (control) (absolute difference [95% confidence interval (CI)], 7% [-10 to 25]), P = 0.59. Mechanical ventilation duration (mean ± SD) was 12.7 ± 9.9 days and 14.1 ± 10.8 days, respectively, P = 0.50; maximal inspiratory pressure increased by 16.6 cm H2O and 4.8 cm H2O, respectively (difference [95% CI], 11.8 [5 to 19]), P = 0.001; and right hemidiaphragm thickening fraction during unassisted spontaneous breathing was +17% and -14%, respectively, P = 0.006, without correlation with changes in maximal inspiratory pressure. Serious adverse event frequency was similar in both groups. Median stimulation-related pain in the treatment group was 0 (no pain). Conclusions: Temporary transvenous diaphragm neurostimulation did not increase the proportion of successful weaning from mechanical ventilation. It was associated with a significant increase in maximal inspiratory pressure, suggesting reversal of the course of diaphragm dysfunction. Clinical trial registered with www.clinicaltrials.gov (NCT03096639) and the European Database on Medical Devices (CIV-17-06-020004).

Effect of pressure controlled volume guaranteed ventilation during pulmonary resection in children.

The purpose of the study was to evaluate the effect of pressure controlled volume guaranteed ventilation in children requiring one lung ventilation during pulmonary resection. Patients were randomly assigned to the lung protective ventilation combined with pressure controlled volume guaranteed group (PCV-VG group) or the lung protective ventilation combined with volume controlled ventilation group (VCV group). Both groups received tidal-volume ventilation of 8 ml kg-1 body weight during two lung ventilation and 6 ml kg-1 during OLV, with sustained 5 cmH2O positive end-expiratory pressure. Data collections were mainly performed at 10 min after induction of anaesthesia during TLV (T1), 5 min after OLV initiation (T2) and 5 min after complete CO2 insufflations (T3). In total, 63 patients were randomly assigned to the VCV (n = 31) and PCV-VG (n = 32) groups. The PCV-VG group exhibited lower PIP than the VCV group at T1 (16.8 ± 2.3 vs. 18.7 ± 2.7 cmH2O, P = 0.001), T2 (20.2 ± 2.7 vs. 22.4 ± 3.3 cmH2O, P = 0.001), and T3 (23.8 ± 3.2 vs. 26.36 ± 3.7 cmH2O, P = 0.01). Static compliance was higher in the PCV-VG group at T1, T2, and T3 (P = 0.01). After anaesthesia induction, lung aeration deteriorated, but with no immediate postoperative difference in both groups. Postoperative lung aeration improved and returned to normal from 2.5 h postextubation in both groups. PH was lower and PaCO2 was higher in VCV group than PCV-VG group during one lung ventilation. No differences were observed in PaO2-FiO2-ratio at T2 and T3, the incidence of postoperative pulmonary complications, intraoperative desaturation and the length of hospital stay. In paediatric patients, who underwent pulmonary resection requiring one lung ventilation, PCV-VG was superior to VCV in its ability to provide lower PIP, higher static compliance and lower PaCO2 at one lung ventilation during pneumothorax. However, its beneficial effects on different pathological situations in pediatric patients need more investigation.

Are maximum respiratory pressures predictors of sarcopenia in the elderly?

OBJECTIVE: To compare maximum respiratory pressures and spirometric parameters among elderly individuals classified as having no sarcopenia, probable sarcopenia, and confirmed sarcopenia, and to test the ability of these variables to discriminate sarcopenia in a community-dwelling elderly population. METHODS: This was a cross-sectional study involving 221 elderly (≥ 60 years of age) individuals of both sexes. Sarcopenia was diagnosed in accordance with the new consensus of the European Working Group on Sarcopenia in Older People. Maximum respiratory pressures and spirometry parameters were assessed. RESULTS: The prevalences of probable sarcopenia and confirmed sarcopenia were 20.4% and 4.1%, respectively. Regardless of the sex, those with confirmed sarcopenia had significantly lower MEP than those with no sarcopenia and probable sarcopenia, whereas only males with confirmed sarcopenia presented with significantly lower MIP than did the other individuals. There was an inverse association of MIP and MEP with sarcopenia, indicating that the decrease by 1 cmH2O in these parameters increases the chance of sarcopenia by 8% and 7%, respectively. Spirometric parameters were not associated with sarcopenia. Cutoff points for MIP and MEP, respectively, were ≤ 46 cmH2O and ≤ 50 cmH2O for elderly women, whereas they were ≤ 63 cmH2O and ≤ 92 cmH2O for elderly men, and both were identified as predictors of sarcopenia (area under the ROC curve > 0.70). CONCLUSIONS: Sarcopenia was associated with lower maximum respiratory pressures, but not with spirometric parameters. Maximum respiratory pressures can be used as markers of sarcopenia in a community-dwelling elderly population regardless of the sex.

Maximal inspiratory pressure is associated with health-related quality of life and is a reliable method for evaluation of patients on hemodialysis.

OBJECTIVE: To evaluate the association between Maximal Inspiratory Pressure (MIP) and health-related quality of life (HRQoL) and to verify the reliability of the MIP in patients on hemodialysis. METHODS: In a repeated-measures design, patients on hemodialysis performed MIP and specific HRQoL questionnaire (trial 1). The MIP was repeated after 6 to 8 weeks (trial 2) and reliability was assessed using Intra-class Correlation Coefficient. Standard Error of Measurement and Minimal Detectable Change scores were calculated. RESULTS: Sixty-one individuals (68.9% men) were evaluated in trial 1. MIP was associated with specific domains "Symptoms" (r = 0.45; R2 adjusted = 0.192) and the kidney disease component summary (r = 0.38; R2 adjusted = 0.138). Regarding generic domains, the MIP was associated with "Physical Functioning" (r = 0.57; R2 adjusted = 0.375) and Physical component summary (r = 0.47; R2 adjusted = 0.258). Thirty-three patients were randomly selected to perform a second MIP test (trial 2). The Intra-class Correlation Coefficient was 0.94 (95%CI 0.88-0.97). By Bland-Altman analysis, the bias was 3.2 cmH2O, which represents a difference of 3.7%. The Standard Error of Measurement and Minimal Detectable Change for MIP were 5.9 cmH2O and 13.8 cmH2O, respectively. CONCLUSION: The MIP is a reliable test, associated with physical domains of HRQoL in patients on hemodialysis. Thus, it is a useful method for respiratory evaluation in this population.

Effects of home-based inspiratory muscle training on sickle cell disease (SCD) patients

ABSTRACT Introduction: Inspiratory muscle training (IMT) has been shown to be an efficient method of improving exercise tolerance and inspiratory and expiratory muscle strength in several diseases. The effects of IMT on patients with sickle cell anemia (SCD) are relatively unknown. Our study aimed to evaluate the effects of IMT on adult SCD patients, regarding respiratory muscle strength (RMS) variables, lung function, exercise tolerance, blood lactation concentration, limitation imposed by dyspnea during daily activities and impact of fatigue on the quality of life. Methods: This was a randomized single-blind study, with an IMT design comprising true load (TG) and sham load (SG) groups. Initial assessment included spirometry, volumetric capnography (VCap) and measurement of RMS by maximal inspiratory and expiratory pressure (PImax and PEmax). The Medical Research Council dyspnea scale and modified fatigue impact scale were also applied and blood lactate concentration was measured before and after the 6-minute walk test. After this initial assessment, the patient used the IMT device at home daily, returning every 6 weeks for RMS reassessment. Both groups used the same device and were unaware of which group they were in. After a period totaling 18 weeks, patients underwent the final evaluation, as initially performed. Results: Twenty-five patients in total participated until the end of the study (median age 42 years). There were no significant differences between TG and SG based on age, sex, body mass index or severity of genotype. At the end of the training, both groups showed a significant increase in PEmax and PImax, improvement in Vcap and in exercise tolerance and dyspnea reduction while performing daily life activities. The same was observed in patients grouped according to disease severity (HbSS and HbSβ0 vs HbSC and HbSβ+), without differences between groups. Conclusion: Home-based inspiratory muscle training benefits outpatients with SCD, including the sham load group. Trial registration:http://www.ensaiosclinicos.gov.br; registration number: RBR-6g8n92.

Respiratory muscle strength and exercise capacity of children and adolescents with chronic liver diseases / Força muscular respiratória e capacidade de exercício de crianças e adolescentes com hepatopatias crônicas

Introdution: Chronic liver diseases are characterized by inflammatory and fibrotic lesions of the liver that cause systemic complications. These complications can negatively interfere with the respiratory muscle strength and exercise capacity of developing children and adolescents. Objectives: to compare respiratory muscle strength and exercise capacity in children and adolescents with chronic hepatopathy, using predicted values from healthy individuals of the same age. Methodology: a cross-sectional study was performed. Children and adolescents from 6 to 16 years old with chronic hepatopathies were included. For the evaluation of respiratory muscle strength, the maximal respiratory pressures were measured through manovacuometry. A six-minute walk test was used to assess exercise capacity. The Wilcoxon test was used to verify the difference between the evaluated and predicted values of the distance traveled. Results: In total, 40 subjects were analyzed; 57.5% of the subjects were female, and the subjects had a mean age of 11.68±2.82 years. In the comparison between the measured and predicted maximal respiratory pressures, a median (IQR) difference of -21,47 (33-95) cmH2O (p< 0.001) was found for the maximal inspiratory pressure, and a mean difference of 30.68±17,16 cmH2O (p< 0.001) was found for the maximal expiratory pressure. Regarding exercise capacity, the measured average distance traveled was 346.46±49.21 m, which was 185.54±63,90 m (p< 0.001) less than the predicted value. Conclusion: Children and adolescents with chronic liver disease have reduced respiratory muscle function and exercise capacity.

Introdução: as doenças hepáticas crônicas são caracterizadas por lesões inflamatórias e fibróticas do fígado que causam complicações sistêmicas. Essas complicações podem interferir negativamente na força muscular respiratória e na capacidade de exercício de crianças e adolescentes em desenvolvimento. Objetivo: comparar a força muscular respiratória e a capacidade de exercício em crianças e adolescentes com hepatopatia crônica, utilizando valores preditos de indivíduos saudáveis da mesma idade. Metodologia: trata-se de um estudo transversal. Foram incluídas crianças e adolescentes de 6 a 16 anos com hepatopatias crônicas. Para a avaliação da força muscular respiratória, as pressões respiratórias máximas foram medidas por meio da manovacuometria. Teste de caminhada de seis minutos foi usado para avaliar a capacidade de exercício. O teste de Wilcoxon foi utilizado para verificar a diferença entre os valores avaliados e previstos da distância percorrida. Resultados: no total, 40 sujeitos foram analisados; 57,5% dos sujeitos eram do sexo feminino, idade média de 11,68±2,82 anos. Na comparação entre as pressões respiratórias máximas medidas e previstas, foi encontrada diferença mediana (IQ) de -21,47 (33-95) cmH2O (p<0,001) para a pressão inspiratória máxima e diferença média de 30,68±17,16 cmH2O (p<0,001) para a pressão expiratória máxima. Em relação à capacidade de exercício, a distância média percorrida foi 346,46±49,21 m, média 185,54±63,90 m (p<0,001) inferior ao valor previsto. Conclusão: crianças e adolescentes com doença hepática crônica apresentam redução da função muscular respiratória e da capacidade de exercício.

Pulmonary function decline in amyotrophic lateral sclerosis.

Background: There has been no comprehensive longitudinal study of pulmonary functions (PFTS) in ALS determining which measure is most sensitive to declines in respiratory muscle strength. Objective: To determine the longitudinal decline of PFTS in ALS and which measure supports Medicare criteria for NIV initiation first. Methods: Serial PFTs (maximum voluntary ventilation (MVV), maximum inspiratory pressure measured by mouth (MIP) or nasal sniff pressure (SNIP), maximum expiratory pressure (MEP), and Forced Vital Capacity (FVC)) were performed over 12 months on 73 ALS subjects to determine which measure showed the sentinel decline in pulmonary function. The rate of decline for each measure was determined as the median slope of the decrease over time. Medicare-based NIV initiation criteria were met if %FVC was ≤ 50% predicted or MIP was ≤ 60 cMH2O. Results: 65 subjects with at least 3 visits were included for analyses. All median slopes were significantly different than zero. MEP and sitting FVC demonstrated the largest rate of decline. Seventy subjects were analyzed for NIV initiation criteria, 69 met MIP criteria first; 11 FVC and MIP criteria simultaneously and none FVC criteria first. Conclusions: MEP demonstrated a steeper decline compared to other measures suggesting expiratory muscle strength declines earliest and faster and the use of airway clearance interventions should be initiated early. When Medicare criteria for NIV initiation are considered, MIP criteria are met earliest. These results suggest that pressure-based measurements are important in assessing the timing of NIV and the use of pulmonary clearance interventions.