The effects of inspiratory muscle training on biomarkers of muscle damage in recovered COVID-19 patients after weaning from mechanical ventilation.

Background: COVID-19 patients experience respiratory muscle damage, leading to reduced respiratory function and functional capacity often requiring mechanical ventilation which further increases susceptibility to muscle weakness. Inspiratory muscle training (IMT) may help mitigate this damage and improve respiratory function and functional capacity. Methods: We studied the effects of IMT on muscle damage biomarkers, respiratory function, and functional capacity in COVID-19 recovered young adults, successfully weaned from mechanical ventilation. Participants were randomly allocated to either an IMT (n = 11) or control (CON; n = 11) intervention for 4 weeks. The IMT group performed 30 dynamic inspiratory efforts twice daily, at 50% of their maximal inspiratory mouth pressure (PMmax) while the CON group performed 60 inspiratory efforts at 10% of pMmax daily. Serum was collected at baseline, week two, and week four to measure creatine kinase muscle-type (CKM), fast skeletal troponin-I (sTnI) and slow sTnI. Results: Time × group interaction effects were observed for CKM and slow sTnI, but not for fast sTnI. Both were lower at two and 4 weeks for the IMT compared to the CON group, respectively. Time × group interaction effects were observed for forced expiratory volume in 1s, forced vital capacity, PMmax and right- and left-hand grip strength. These were higher for the IMT compared to the CON group. Conclusion: Four weeks of IMT decreased muscle damage biomarkers and increased respiratory function and grip strength in recovered COVID-19 patients after weaning from mechanical ventilation.

The benefits of early pulmonary rehabilitation with incentive spirometer among chronic obstructive pulmonary disease patients with exacerbation of chronic obstructive pulmonary disease.

INTRODUCTION: Inspiratory muscle dysfunction is prevalent in chronic obstructive pulmonary disease (COPD). This study aimed to compare the benefits of adding volume incentive spirometry (VIS) to active-cycle-breathing technique (ACBT) and ground-based walking (GBW) training in patients hospitalised for COPD exacerbations. The objectives were to evaluate the impact of early initiation of VIS on respiratory muscle strength, measured by maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP) and the 6-minute walk test (6-MWT), as well as on symptoms, as assessed by the COPD assessment test (CAT) score. MATERIALS AND METHODS: This randomised, prospective study was conducted among COPD subjects admitted with exacerbation between June 2021 and August 2022. Subjects were randomly assigned to either the VIS (interventional group) or the control group. Baseline assessments, including spirometry, MIP, CAT score, and the 6-minute walk test (6MWT), were performed. Both groups commenced active cycle of breathing techniques (ACBT) and groundbased walking (GBW) training within 72 hours of admission, with daily sessions involving three repetitions of each phase to complete one cycle, repeated three times daily. The intervention group received VIS. Upon discharge, subjects were provided with a diary and instructed to continue a home-based pulmonary exercise regimen, performed for at least 15 minutes per day, 3 days a week, with compliance monitored through weekly phone calls. At the 4-week followup, repeat assessments of spirometry, MIP, maximal expiratory pressure (MEP), CAT score and 6MWT were conducted to evaluate the outcomes. RESULTS: A total of 34 subjects with a median age of 68 years (interquartile range [IQR] 65-74.3 years). The cohort predominantly males (32 subjects, 94%). The distribution of disease severity was as follows: GOLD 2 in 15 subjects (44%) and GOLD 3 in 14 subjects (41%). Additionally, 17 subjects (50%) had experienced three or more exacerbations in the preceding year. The majority of patients (29 out of 34, 85%) had a length of stay of less than 7 days. In the interventional group, the median MIP improved from 50 cm H2O (IQR 40.5-70.5) to 59 cm H2O (IQR 39-76.5), though this was not statistically significant (p = 0.407). The control group saw an improvement from 58 cm H2O (IQR 36.5-85) to 60 cm H2O (IQR 33-88), also not statistically significant (p = 0.112). The 6MWT distance improved in the interventional group from 220 meters (IQR 118-275) to 260 meters (IQR 195-327) (p = 0.002) and in the control group from 250 meters (IQR 144-294) to 280 meters (IQR 213-359.5) (p = 0.001). The median CAT score decreased significantly in the interventional group from 22 (IQR 16-28) to 11 (IQR 7.5-13) (p < 0.001) and in the control group from 21 (IQR 14-24.5) to 10 (IQR 8-12.5) (p < 0.001). CONCLUSION: Early initiation of pulmonary rehabilitation in patients with acute exacerbations, characterised by poor muscle strength and a history of exacerbations, resulted in significant improvements in patient-reported symptoms and 6MWT outcomes. Although there was only a numerical improvement in MIP and MEP, the intervention did not extend the length of hospital stay, highlighting its safety and efficacy in the acute care setting.

Benefits of inspiratory muscle training therapy in institutionalized adult people with cerebral palsy: A double-blind randomized controlled trial.

BACKGROUND: Respiratory health problems are one of the main causes of morbidity and mortality in adult people with cerebral palsy (CP). The influence of respiratory muscle training has not yet been studied in this population group. The objective of the study was to evaluate and compare the efficacy of two protocols with inspiratory muscle training (IMT), low intensity and high intensity, to improve respiratory strength and pulmonary function in adults with CP. METHODS: The study was a controlled, randomized, double-blind trial with allocation concealment. Twenty-seven institutionalized CP patients were recruited and randomly distributed in the high-intensity training group (HIT) or low-intensity training group (LIT). Over 8 weeks, an IMT protocol was followed 5 days/week, 10 series of 1 min with 1 min rest between them. HIT trained with a load of 40% of the maximum inspiratory pressure (MIP) and LIT with 20%. Respiratory strength and pulmonary function were evaluated. RESULTS: After IMT intervention, MIP, maximum expiratory pressure, forced expiratory volume in 1 s (FEV1) and peak expiratory flow increased in both groups; in HIT 29%, 19%, 13%, and 8%, respectively (p = 0.000, p = 0.000, p = 0.002, p = 0.001) and in LIT 17%, 7%, 3%, and 4%, respectively (p = 0.000, p = 0.000, p = 0.049, p = 0.113). All the improvements were significantly higher in HIT than in LIT. CONCLUSION: Inspiratory muscle training improved respiratory muscle strength and pulmonary function in adults with CP. Training with a 40% MIP load improved all the evaluated parameters and was the most effective treatment for adults with CP.

Does multifactorial inspiratory muscle training improve postural stability and quality of life of patients with diabetes in Pakistan? A randomised controlled trial.

OBJECTIVE: To determine the effects of multifactorial inspiratory muscle training (IMT) combined with Otago Exercise Programme (OEP) on balance and quality of life (QoL) in patients with diabetes. METHODS: Pretest-post-test randomised controlled trial. SETTING: Rehabilitation Department of Pakistan Railway General Hospital. PARTICIPANTS: 70 patients with diabetes were randomly assigned to experimental or placebo groups, out of which 59 patients completed the intervention. INTERVENTION: Patients in the experimental group performed OEP+IMT (at 50% of baseline maximum inspiratory pressure (MIP)) whereas the placebo group performed OEP+sham IMT (at 15% of MIP). Both groups exercised for 12 consecutive weeks. OUTCOME MEASURES: Outcome measures included nine variables: the Berg Balance Scale (BBS), the Biodex Postural Stability System (including postural stability test (Overall Stability Index, Anterior-Posterior Index and Mediolateral Index), fall risk test (FRT), Limits of Stability (LOS) test (time to complete test and direction control), Clinical Test of Sensory Interaction and Balance (CTSIB)) and the Audit of Diabetes Dependent Quality of Life questionnaire. RESULTS: Out of 59 patients who completed treatment, 37.1% were men and 62.9% were women with a mean age of 58.37±5.91 years. Results show significant interaction effects on BBS scores with the mean score improving from 41.87±2.61 to 49.16±2.50 in IMT versus sham IMT group with scores improving from 41.58±2.51 to 45.74±2.30. The IMT group significantly improved in dynamic balance tested through BBS (p=0.003), anticipatory balance through LOS test (p=0.003), reactive balance tested through FRT (p=0.04), direction control (p=0.03) and sensory integration through CTSIB test (p=0.04) when compared with the sham IMT group. While no significant changes (p>0.05) between groups were observed in QoL and static balance; significant changes (p<0.05) within group were observed in both groups in QoL and static balance. CONCLUSION: Additional research is necessary to understand the association between inspiratory muscle strength and balance, however, we demonstrated that a multifactorial IMT intervention should be used with patients with diabetes to improve balance, postural control and reduce fall risks. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov, NCT#04947163.

Inspiratory muscle strength training to improve cardiometabolic health in patients with type 2 diabetes mellitus: protocol for the diabetes inspiratory training clinical trial.

Type 2 diabetes mellitus (T2DM) is a complex, chronic metabolic disease that carries with it a high prevalence of comorbid conditions, making T2DM one of the leading causes of death in the U.S. Traditional lifestyle interventions (e.g., diet, exercise) can counter some adverse effects of T2DM, however, participation in these activities is low with reasons ranging from physical discomfort to lack of time. Thus, there is a critical need to develop novel management strategies that effectively reduce cardiometabolic disease risk and address barriers to adherence. High-resistance inspiratory muscle strength training (IMST) is a time-efficient and simple breathing exercise that significantly reduces systolic and diastolic BP and improves vascular endothelial function in adults with above-normal blood pressure. Herein we describe the study protocol for a randomized clinical trial to determine the effects of a 6-week IMST regimen on glycemic control and insulin sensitivity in adults with T2DM. Our primary outcome measures include fasting plasma glucose, fasting serum insulin, and insulin resistance utilizing homeostatic model assessment for insulin resistance (HOMA-IR). Secondary outcome measures include resting systolic BP and endothelium-dependent dilation. Further, we will collect plasma for exploratory proteomic analyses. This trial seeks to establish the cardiometabolic effects of 6 weeks of high-resistance IMST in patients with T2DM.

Multifactorial inspiratory muscle training and its impact on respiratory and functional parameters of patients with diabetic polyneuropathy-A Randomized Controlled Trial.

BACKGROUND AND PURPOSE: Diabetic polyneuropathy is a long-standing microvascular complication of diabetes that affects the postural control and functional mobility of patients. There are other microvascular complications, including pulmonary complications that reduce lung function. Multifactorial Inspiratory Muscle Training (IMT) can act as a home-based technique targeted to affect both these complications. This study aims to determine the effects of IMT on respiratory and functional parameters in diabetic polyneuropathy patients. METHODS: This is a Pre-Test Post-Test Randomized Controlled Trial (NCT#04947163) with 62 diabetic polyneuropathy patients. Each was randomly assigned to the IMT or sham-IMT group. Both the groups performed OTAGO exercises , with the sham-IMT group performing IMT at 15% of baseline maximal inspiratory pressure (MIP), whereas IMT were trained at 50% of baseline MIP as an initial intensity, which was increased as per the tolerance of patients. Both groups performed training for 12 weeks. The study investigated diaphragmatic strength, pulmonary function, functional capacity through 6MWT, 30s sit to stand test and anterior trunk muscle endurance tested through sit up test as outcome variables. Data was analysed on SPSS v26 at the significance level of 0.0.5. RESULTS: The IMT group significantly improved diaphragmatic strength, pulmonary function, 6MWT and anterior trunk muscle endurance when compared to the sham-IMT group. CONCLUSION: The study concluded that home-based IMT can improve pulmonary parameters including diaphragmatic strength and lung function as well as functional parameters including functional capacity in patients with diabetic polyneuropathy. The study was registered at ClinicalTrials.gov, NCT#04947163.

Inspiratory Muscle Training for Lung Transplant Candidates and Recipients.

OBJECTIVES: Inspiratory muscle training is used in rehabilitation to exercise respiratory muscles in various conditions associated with limited ventilatory reserve. In this review, we investigated inspiratory muscle training in lung transplant candidates and recipients. MATERIALS AND METHODS: We searched 5 primary databases from inception through April 2024. Two key word entries, "lung transplantation" and "inspiratory muscle training," were matched using the Boolean operator AND. No filters were applied for document type, age, sex, publication date, language, and subject. RESULTS AND CONCLUSIONS: The searched databases returned 119 citations. Seven articles that considered 64 patients (47% female) were included in the final analysis, with 1 study involving a pediatric patient. Lung transplant recipients used a threshold trainer at 15% to 60% of maximal inspiratory pressure and mostly exercised twice daily for 10 to 15 minutes per session. Lung transplant candidates exercised at 30% to >50% of maximal inspiratory pressure twice daily, performing 30 to 60 inspirations or for 15 minutes. The highest inspiratory muscle strength was observed in a series of adult lung transplant recipients whose mean value improved by 31.8 ± 14.6 cmH2O versus baseline after treatment. To the same extent, the highest value of maximal inspiratory pressure was detected in a pediatric patient who scored 180 cmH2O after training. Overall, participants obtained improvements in lung function (forced expiratory volume in 1 second, forced vital capacity), functional performance, dyspnea intensity, and exercise tolerance. Inspiratory muscle training is easy to perform and can be done at home without specific supervision (in adults) before or after a lung transplant. Nevertheless, additional rigorous investigations should aim to replicate the positive effects reported in the present review.

Incidence and influencing factors for respiratory sarcopenia in older adults: The first longitudinal evidence from the CHARLS.

AIM: Respiratory sarcopenia (RS) has been newly defined in a position paper by four professional organizations in Japan, and it is necessary to examine its incidence and influencing factors using this new definition. So far, little work has been undertaken; we therefore conducted a longitudinal study to fill this gap. METHODS: Our data were extracted from the China Health and Retirement Longitudinal Study. A total of 4301 older adults with complete data and without RS were chosen in 2011, of whom 3065 were followed up until 2015. The presence of low respiratory muscle strength plus low appendicular skeletal muscles mass was defined as RS based on t. A logistic regression model was used to identify the influencing factors for incident RS. RESULTS: After an average of 4 years of follow-up, the cumulative incidence of RS was 5.2%, and it was particularly high in participants aged >80 (20.9%). Logistic regression analysis showed that being unmarried/divorced/widowed (odds ratio [OR] = 1.85, 95% confidence interval [CI] = 1.28-2.66, P = 0.001), not having dyslipidemia (OR = 0.35, 95% CI = 0.19-0.65, P = 0.001), having digestive disease (OR = 1.56, 95% CI = 1.11-2.19, P = 0.010), asthma (OR = 2.77, 95% CI = 1.55-4.94, P = 0.001), edentulism (OR = 1.73, 95% CI = 1.24-2.42, P = 0.001), low handgrip strength (OR = 2.82, 95% CI = 1.99-3.99, P < 0.001), or low 5-m gait speed (OR = 1.92, 95% CI = 1.23-3.01, P = 0.004) were associated with a greater likelihood of developing RS. After further adjustment for age and body mass index, asthma, edentulism, and low handgrip strength remained significant. CONCLUSIONS: The identification and management of older adults with the influencing factors described above could be important in preventing RS. Geriatr Gerontol Int 2024; 24: 1015-1021.

The Effect of Inspiratory Muscle Training on Health-Related Fitness in College Students.

In an era characterized by rapid economic growth and evolving lifestyles, college students encounter numerous challenges, encompassing academic pressures and professional competition. The respiratory muscle endurance capability is important for college students during prolonged aerobic exercise. Therefore, it is of great significance to explore an effective intervention to enhance the endurance level of college students. This study explores the transformative potential of inspiratory muscle training (IMT) to improve the physical functions of college students. This research comprised a group of 20 participants who underwent IMT integrated into their daily physical education classes or regular training sessions over an 8-week period, with 18 participants forming the control group. The IMT group adhered to the manufacturer's instructions for utilizing the PowerBreathe device. The findings indicated a significant positive effect on inspiratory muscle strength (p < 0.001), showing improvements in pulmonary function, exercise tolerance, cardiac function, and overall athletic performance. These results revealed the substantial benefits of IMT in enhancing physical fitness and promoting health maintenance among college students.

Effect of Inspiratory Muscle Training on Outcomes After Cardiac Surgery: A Comprehensive Meta-Analysis of Randomized Controlled Trials.

PURPOSE: Inspiratory muscle training (IMT) has emerged as a potential intervention to improve respiratory outcomes for patients undergoing cardiac surgery. However, the extent of the IMT effects on preoperative and postoperative respiratory metrics remains uncertain. Hence, we designed this study to determine the effects of IMT on various outcomes of patients undergoing cardiac surgery. METHODS: We conducted a comprehensive meta-analysis of studies evaluating the impact of preoperative and postoperative IMT on various respiratory variables and postsurgical outcomes. We synthesized data from multiple studies, encompassing diverse patient populations and IMT protocols. The key outcomes included the maximal inspiratory pressure (MIP), forced expiratory volume in 1 sec (FEV1), forced vital capacity (FVC), and others. RESULTS: Our meta-analysis results showed that preoperative IMT significantly improved the MIP values with a pooled standard mean difference (SMD) of 0.62. The hospital stay length was also reduced with a SMD of - 0.4. Other variables such as FEV1 and FVC also improved significantly. Postoperative IMT improved the MIP and peak flow rate values, but the evidence was less robust than with preoperative interventions. We observed high heterogeneity across studies for several outcomes and found evidence of publication bias for some postoperative measures. CONCLUSION: Both preoperative and postoperative IMT offer benefits for patients undergoing operations, especially by enhancing respiratory muscle strength and potentially reducing hospital stays. However, the presence of heterogeneity and publication bias underscores the need for further standardized research to consolidate these findings and standardize IMT protocols for optimal patient outcomes.

The Application of Self-Made Disseminating and Descending Breathing Exercises in Home Rehabilitation of Stable COPD.

To investigate the clinical effects and application value of self-made disseminating and descending breathing exercises on home rehabilitation of patients with stable chronic obstructive pulmonary disease (COPD). Seeking to generate concepts for creating novel, convenient, and efficient COPD prognosis rehabilitation exercises aimed at enhancing the well-being and rehabilitation confidence of both COPD patients and their families. A total of 70 COPD patients admitted to our outpatient department from July 2019 to September 2021 were randomly divided into the exercise group (n = 35) and the control group (n = 35). The control group received routine breathing training, while the exercise group was treated with self-made disseminating and descending breathing exercises. The respiratory function, including pulmonary function (FVC, FEV1, FEV1/FVC) and respiratory muscle strength (MIP, MEP), exercise tolerance (6-min walking distance, 6MWT), Modified Medical Research Council Dyspnea Scale (mMRC, Borg), COPD quality of life score (CAT, SGRQ), anxiety and depression scores (HAMA, HAMD) were compared between the two groups after 12-week exercise. After 12-week training, the FEV1, MIP, and MEP in the exercise group were significantly higher than those in the control group (p < 0.001), and the 6MWT was significantly increased in the exercise group compared to the control group (p < 0.001); while the mMRC, Borg score, the scores of CAT, SGRQ, HAMA, and HAMD were found significantly lower than those in the control group (p < 0.001). The self-made disseminating and descending breathing exercises can improve respiratory function and reduce symptoms of dyspnea in COPD patients, while enhancing exercise tolerance and relieving anxiety and depression, and are worthy of clinical application.

Functional Sitting Balance and Anthropometric Measures Are Related to Inspiratory Muscle Performance in People with Spinal Cord Injury.

Background: Respiratory complications are a leading cause of mortality post spinal cord injury (SCI). Along with breathing, respiratory muscles have a role in maintaining seated balance. Postinjury breathing influences respiratory muscle function. Preliminary evidence indicates a relation between respiratory muscle function and seated balance in people with chronic SCI dwelling in the community, but the relationship between balance and body habitus has not been explored. Objectives: To explore the relationships among inspiratory muscle function, functional seated balance (FSB), and body habitus in people with SCI. Methods: A convenience sample of inpatients with SCI (C5-T12) aged 18 to 60 years who were using a wheelchair was recruited from November 2022 to March 2023. Those with additional neurological disorders or respiratory support were excluded. Respiratory muscle function measures included maximal inspiratory pressure (MIP), sustained MIP (SMIP), and Fatigue Index Test (FIT). FSB was scored using the Function in Sitting Test (FIST). Body habitus was assessed using the axillary: umbilical (A:U) ratio. Spearman correlations explored the relationships. Results: Thirty-eight of 42 screened participants were eligible and participated (male, 32). Levels of injury ranged from C5 to T12. The mean (SD) age and duration of injury of the sample was 25.61 (6.68) years and 31.03 (28.69) months, respectively. SMIP and FIT correlated significantly with FSB (r s= .441, p = .01, and r s= .434, p = .006, respectively). A significant correlation between SMIP and A:U ratio (r s= -.330, p = .043) was observed. Conclusion: We observed a significant correlation between inspiratory pressure parameters and both functional seated balance and body habitus, adding to evidence on postural role of respiratory muscles.

Effects of preoperative respiratory muscle training for improvement of postoperative health related quality of life in mitral valve replacement patients.

BACKGROUND AND PURPOSE: A patient's defective mitral valve is replaced as part of a treatment called mitral valve replacement (MVR) with a mechanical or biological (bioprosthetic) valve. To evaluate the effects of preoperative respiratory muscle training (RMT) on the improvement of postoperative Health related quality of life in MVR patients. METHODS: A quasi-experimental study was conducted at Faisalabad Institute of Cardiology. A Sample of 40 adult patients aged 25-50 years of both genders who underwent MVR was selected and divided into two groups Group 1 (Respiratory Muscle Training Group) was received RMT consisting of 10-15 repetitions a day for 5 days; for 3 weeks. Whereas Group 2 (Conventional Group) was receive breathing exercise consisting of 10-12 repetitions a day for 5 days; for 3 weeks. Modified Healthy Heart Questionnaire (HHQ-GP-1) was used as screening tool. In outcome measuring tools Health Related Quality of life Questionnaire (EuroQol), New York Heart Association, was used at baseline, 3rd week and postoperatively. Duration of Postoperative Mechanical Ventilation (hours) and Hospital Stay was also noted as outcome measures of this study. RESULTS: Results obtained indicate that level of Self-Care in EuroQol-5-D-5L has improved in group 1 3.35 ± 1.03 to 1.35 ± 0.48 showing significant improvement similarly in case of Hospital Length of Stay, Mechanical ventilation 4.05 ± 0.68 to 5.05 ± 0.51 and Pain 65.25 ± 8.34 to 71.50 ± 6.70 has improved. IMPLICATIONS ON PHYSIOTHERAPY PRACTICE: It was concluded that Respiratory Muscle Training and Conventional Muscle Training both are effective in MVR patients. But RMT is more effective in improving self-care, reducing pain, Hospital Length of Stay and Mechanical Ventilation in postoperative period as compared to Conventional Muscle Treatment.

Respiratory muscle strength in stroke: a case-control study.

AIM: The aim of the study was to determine the respiratory muscle strength of stroke patients and compare them with healthy individuals. METHOD: The study was conducted with 171 patients who had a stroke between 2017 and 2021 and 32 healthy controls. Respiratory muscle strength and inspiratory and expiratory mouth pressure (MIP and MEP) were measured using the portable MicroRPM device (Micro Medical, Basingstoke, UK). RESULTS: The stroke group exhibited significantly lower values in both MIP for men (p<0.001) and women (p=0.013) and maximal expiratory pressure for men (p<0.001) and women (p=0.042), compared with the healthy control group. Notably, there was a significant difference in the MIPmen (p=0.026) and MEPmen (p=0.026) values when comparing the reference values, which were calculated based on age and sex, with those of the healthy group. The baseline values calculated according to age for stroke patients were as follows: MIPmen 31.68%, MIPwomen 63.58%, MEPmen 22.54%, and MEPwomen 42.30%. CONCLUSION: This study highlights the significant respiratory muscle weakness experienced by stroke patients, with gender-specific differences. It highlights the importance of incorporating respiratory assessments and interventions into stroke rehabilitation protocols to improve the overall health and well-being of stroke patients.

Use of pressure muscle index to guide pressure support ventilation setting: a study protocol and statistical plan for a prospective randomised controlled proof-of-concept trial.

INTRODUCTION: Although pressure support ventilation is one of the most commonly used assisted ventilation modes in intensive care units, there is still a lack of precise strategies for setting pressure support. By performing an end-inspiratory airway occlusion, the difference between the peak and plateau airway pressure, which is defined as pressure muscle index (PMI), can be easily measured on the ventilator screen. Previous studies have shown that PMI is accurate in detecting high and low inspiratory effort. No study has been conducted to investigate the use of PMI as an indicator for setting inspiratory pressure support. METHOD AND ANALYSIS: This is a study protocol for a prospective, single-centre, randomised controlled, pilot trial. Sixty participants undergoing pressure support ventilation will be randomly assigned in a 1:1 ratio to the control group or intervention group, with pressure support adjusted according to standard care or guided by the PMI strategy for 48 hours, respectively. The feasibility of the PMI-guided strategy will be evaluated. The primary endpoint is the proportion of inspiratory effort measurements within a well-accepted 'normal' range, which is predefined as oesophageal pressure-time product per minute between 50 and 200 cmH2O⋅s/min, for each patient during 48 hours of pressure support adjustment. ETHICS AND DISSEMINATION: The study protocol has been approved by Beijing Tiantan Hospital (KY2023-005-02). The data generated in the present study will be available from the corresponding author on reasonable request. The results of the trial will be submitted to international peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT05963737; ClinicalTrials.org.

Influence of an inspiratory muscle fatigue protocol on healthy youths on respiratory muscle strength, vertical jump performance and muscle oxygen saturation: a randomized controlled trial.

BACKGROUND: Inspiratory muscle fatigue has been shown to have effects on limbs blood flow and physical performance. This study aimed to evaluate the influence of an inspiratory muscle fatigue protocol on respiratory muscle strength, vertical jump performance and muscle oxygen saturation in healthy youths. METHODS: A randomized and double-blinded controlled clinical trial, was conducted. Twenty-four participants aged 18-45 years, non-smokers and engaged in sports activity at least three times a week for a minimum of one year were enrolled in this investigation. Participants were randomly assigned to three groups: Inspiratory Muscle Fatigue (IMFG), Activation, and Control. Measurements of vertical jump, diaphragmatic ultrasound, muscle oxygen saturation, and maximum inspiratory pressure were taken at two stages: before the intervention (T1) and immediately after treatment (T2). RESULTS: The IMFG showed lower scores in muscle oxygen saturation and cardiorespiratory variables after undergoing the diaphragmatic fatigue intervention compared to the activation and control groups (p < 0.05). For the vertical jump variables, intragroup differences were found (p < 0.01), but no differences were shown between the three groups (p > 0.05). CONCLUSIONS: Inspiratory muscle fatigue appears to negatively impact vertical jump performance, muscle oxygen saturation and inspiratory muscle strength in healthy youths. TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT06271876. Date of registration 02/21/2024. https://clinicaltrials.gov/study/NCT06271876 .

A cross-sectional study in 18 patients with typical and mild forms of nemaline myopathy in the Netherlands.

Nemaline myopathy (NM) is a congenital myopathy with generalised muscle weakness, most pronounced in neck flexor, bulbar and respiratory muscles. The aim of this cross-sectional study was to assess the Dutch NM patient cohort. We assessed medical history, physical examination, quality of life (QoL), fatigue severity, motor function (MFM), and respiratory muscle function. We included 18 of the 28 identified patients (13 females (11-67 years old); five males (31-74 years old)) with typical or mild NM and eight different genotypes. Nine patients (50 %) used a wheelchair, eight patients (44 %) used mechanical ventilation, and four patients (22 %) were on tube feeding. Spinal deformities were found in 14 patients (78 %). The median Medical Research Council (MRC) sum score was 38/60 [interquartile range 32-51] in typical and 48/60 [44-50] in mild NM. The experienced QoL was lower and fatigue severity was higher than reference values of the healthy population. The total MFM score was 55 % [49-94] in typical and 88 % [72-93] in mild NM. Most of the patients who performed spirometry had a restrictive lung function pattern (11/15). This identification and characterisation of the Dutch NM patient cohort is important for international collaboration and can guide the design of future clinical trials.

Respiratory physiological mechanism of two types of equal-intensity inspiratory muscle training in stable patients with chronic obstructive pulmonary disease.

PURPOSE: This study aimed to investigate the respiratory physiological changes resulting from short-term inspiratory resistance training (R-IMT) and inspiratory threshold training (T-IMT) in patients with chronic obstructive pulmonary disease (COPD) and to compare the mechanisms of the two training methods. PATIENTS AND METHODS: A total of 75 stable patients with COPD combined with inspiratory muscle weakness were randomly allocated to three groups: R-IMT (n = 26), T-IMT (n = 24), and control (n = 25). Before and after 8 weeks of inspiratory muscle training(IMT), cardiopulmonary exercise tests were conducted to assess respiratory patterns, respiratory central drive, exercise tolerance, and ventilation efficiency. RESULTS: After 8 weeks of IMT, Inspiratory muscle strength, represented by MIP (maximum inspiratory mouth pressure) and exercise capacity increased during exercise in both IMT groups (P < 0.05). In the R-IMT group, inspiratory time (Ti) prolonged (P < 0.05), tidal volume (Vt) increased (P < 0.05), ventilation efficiency (represented by ventilation-center coupling) increased (P < 0.05) during exercise. Conversely, the T-IMT group did not exhibit any of these changes after IMT (P > 0.05). CONCLUSION: In summary, the improvement in exercise tolerance was associated with an increase in inspiratory muscle reserve in both R-IMT and T-IMT. However, only R-IMT was associated with deeper and slower breathing, as well as improved ventilation efficiency.

Updates in inspiratory muscle training for older adults: A systematic review.

Systematic reviews support the benefits of inspiratory muscle training (IMT) for exercise performance. Recently, many health benefits from IMT have been reported in older adults. Therefore, this work reviewed the literature focusing on IMT effects beyond physical performance in older adults, such as cardiorespiratory, metabolic, and postural balance outcomes. Searches were conducted with the following terms: ("respiratory muscle training" OR "inspiratory muscle training") OR ("inspiratory muscle strength training") AND ("elderly" OR "older" OR "aging" OR "aging"), and using the databases: MEDLINE (PubMed), SCOPUS and EUROPE PMC. Of the 356 articles found, 13 matched the inclusion criteria after screening. Based on reviewed studies, four to eight weeks of IMT (Mostly from 50 % up to 75 % of MIP, 7 days/week) improve cardiac autonomic control at rest and post-exercise, cerebrovascular response to orthostatic stress, static and dynamic balance, blood pressure control, endothelial function, and oxidative stress in older adults. The benefits of IMT in cardiac autonomic and vascular functions are reversed after training cessation. It thus appears that IMT promotes broad physiological gains for the older population. It is necessary to carry out more randomized clinical trials on the subject to confirm the findings of this research.

Respiratory muscular strength in children with mucopolysacaridosis: comparison with predictive equations.

BACKGROUND: Mucopolysaccharidoses (MPS) are rare metabolic diseases that impair respiratory function leading to respiratory failure. This study aimed to compare maximal inspiratory and expiratory pressures (MIP and MEP) obtained in children with MPS and compare with predicted values from previous studies involving healthy children. METHODS: This is a cross-sectional study, in which the chest deformity was evaluated; MIP, MEP through digital manometer, and lung function through spirometry. MIP and MEP were compared with five different predict equations and with a control group of healthy children. Agreement between respiratory muscle weakness regarding absolute values of MIP and MEP in relation to predictive values by the equations included in the study were assessed by Kappa coefficient. RESULTS: MPS group was composed of 22 subjects. 45.5% had pectus carinatum, 36.4% pectus excavatum, and presented lower MIP (37.14±36.23 cmH2O) and MEP (60.09±22.3 cmH2O) compared with control group (22 healthy subjects) (MIP: 91.45±35.60; MEP: 95.73±22.38). Only the MEP equations proposed by Tomalak et al. were close to those found in our MPS children (P=0.09). In the MPS group it was observed a weak agreement between inspiratory weakness through absolute and predicted values in only two equations: Tomalak et al. and Domenèch-Clar et al. (for both: k=0.35, P value =0.03); and for MEP a moderate agreement was found using all predictive equations. CONCLUSIONS: In MPS children MRP data should not be normalized using the reference equations for healthy ones, is more coherent to longitudinally follow absolute pressures and lung volumes in this group.