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Context and Objectives: Respiratory muscle training (RMT) is considered an effective tool to improve cardiorespiratory limitations in athletes. The goals of this systematic review were to explore the role of RMT and its implementation within sport rehabilitation programs in para-athletes. Evidence Acquisition: Several databases were searched until January 2024. Eligible studies were independently reviewed by 2 reviewers. Quality assessment was made using the PEDro scale and version 2 of the Cochrane Risk-of-Bias Tool for Randomized Trials. Eight studies (a total of 108 participants) were selected for the analysis. Evidence Synthesis: Five studies preferred using resistive loading, while 2 studies used normocapnic hyperpnea, and 1 study used threshold inspiratory muscle training. Respiratory functions (respiratory muscle strength and endurance, spirometry measures) and exercise performance were assessed as the main outcomes. Significant increases in respiratory muscle strength were reported in 5 studies. Two studies observed improvement in respiratory muscle endurance and 3 studies reported increased exercise capacity. Conclusions: This review suggests that although RMT can enhance respiratory muscle strength and endurance, it should not be considered the primary method for boosting the exercise performance of para-athletes. Additional research is necessary to explore the impact of various RMT techniques on different outcomes from the perspective of sport rehabilitation in para-athletes. [ABSTRACT FROM AUTHOR]

OBJECTIVES: To examine the feasibility of individuals with spinal cord injury or disease (SCI/D) to perform combined oropharyngeal and respiratory muscle training (RMT) and determine its impact on their respiratory function. METHODS: A prospective study at a single Veterans Affairs (VA) Medical Center. Inclusion criteria included: 1) Veterans with chronic SCI/D (>6 months postinjury and American Spinal Injury Association (ASIA) classification A-D) and 2) evidence of OSA by apnea-hypopnea index (AHI ≥5 events/h). Eligible participants were randomly assigned to either an experimental (exercise) group that involved performing daily inspiratory, expiratory (using POWERbreathe and Expiratory Muscle Strength Trainer 150 devices, respectively), and tongue strengthening exercises or a control (sham) group that involved using a sham device, for a 3-month period. Spirometry, maximal expiratory pressure (MEP), maximal inspiratory pressure (MIP), polysomnography, and sleep questionnaires were assessed at baseline and at 3 months. RESULTS: Twenty-four individuals were randomized (12 participants in each arm). A total of eight (67%) participants completed the exercise arm, and ten (83%) participants completed the sham arm. MIP was significantly increased (p

To stratify groups of infants by gestational age and identify the lower limit of normal (LLN) of the cross-sectional area of peripheral muscles as well as diaphragmatic excursion and thickness and parasternal activation during spontaneous respiration in full-term and preterm newborns. A cross-sectional study was conducted at a neonatal unit. Preterm newborns (PTNBs) with gestational age of 28 to 366/7 weeks and full-term newborns (NBs) with gestational age of 37 to 416/7 weeks, clinically and hemodynamically stable, breathing ambient air with no signs of respiratory distress were included. NBs on oxygen therapy, those with known genetic syndromes, malformations of the nervous system and those having undergone surgery were excluded. Ultrasound was performed over the rectus femoris, tibialis anterior, and biceps brachii muscles (cross-sectional area) and diaphragm (thickness and excursion). One hundred twenty NBs were stratified based on gestational age (< 30 weeks [n = 25]; 31 to 35 weeks [n = 51]; 37 to 41 6/7 weeks [n = 44]). Significant differences were found in the cross-sectional area of the rectus femoris muscles and thigh circumference of NBs > 37 weeks compared to the other 2 groups (p < 0.05). Differences were found in diaphragm thickness and excursion between the groups with gestational age > 37 weeks and < 30 weeks. Greater activation of the parasternal muscles was found in the PTNBs. With regard to LLN, significant differences were found between the groups with gestational age > 37 weeks and < 30 weeks for all variables analyzed and between the group with gestational age > 37 weeks and other 2 groups for the cross-sectional area of the rectus femoris, diaphragmatic excursion, and diaphragm contraction velocity. Differences were found among the groups in the size of peripheral muscles as well as diaphragm thickness and excursion. Moreover, greater activation of the parasternal muscle was found in NBs with gestational age < 30 weeks. This study establishes normal values of ultrasound measures for full-term and preterm newborns. [ABSTRACT FROM AUTHOR]

Background: Heart failure may cause peripheral and respiratory muscle alterations, dyspnea, fatigue, and exercise intolerance, worsening the quality of life of patients. Objectives: The aims of this study were to analyze respiratory muscle strength and quality of life of patients with heart failure and correlate them with clinical variables and functional classification. Methods: This cross-sectional study involved patients with heart failure. A manovacuometer assessed maximum inspiratory and expiratory pressures, and quality of life was assessed using the Minnesota Living with Heart Failure Questionnaire. Functional classification was categorized according to the New York Heart Association (NYHA) class in I, II, III, or IV. Results: We included 60 patients (66.7%male) with a mean age of 62.0 years and mean left ventricular ejection fraction of 42.0%. Maximum inspiratory pressure and maximum expiratory pressure were close to normal (>70% of predicted) in most patients; however, a subgroup composedmostly of patients with dilated heart failure and NYHA class III (n = 21) presented lowmaximum inspiratory pressure values (59.2%; 95%confidence interval, 55.7%-62.8%). The mean total score of theMinnesota Livingwith Heart Failure Questionnairewas 44.4 points, being negatively correlated with left ventricular ejection fraction (r = -0.29, P = .02). Patients withNYHAclass III and disease duration longer than 120months presented higher total (P < .01) and physical dimension scores. Conclusions: Most patients had respiratory muscle strength close to normal; however, thosewith dilated heart failure and NYHA class III presented lowmaximum inspiratory pressure values. Quality of life wasmoderately compromised, mainly because of long disease duration, NYHA class III, and low left ventricular ejection fraction. [ABSTRACT FROM AUTHOR]

• Progressive exercise intolerance is a hallmark in pulmonary hypertension (pH.) • Pre-clinical and clinical studies published in the last 10 years strengthens the integrated nature of the pH physiopathology via functional and structural changes in the peripheral reflexes (such as peripheral chemoreflex and baroreflex) and in the respiratory, cardiovascular and musculoskeletal systems. • These findings shed light into future therapeutic targets that can assist in improving exercise tolerance and quality of life in patients with pH. Background: Progressive exercise intolerance is a hallmark of pulmonary hypertension (pH), severely impacting patients' independence and quality of life (QoL). Accumulating evidence over the last decade shows that combined abnormalities in peripheral reflexes and target organs contribute to disease progression and exercise intolerance. Objective: The aim of this study was to review the literature of the last decade on the contribution of the cardiovascular, respiratory, and musculoskeletal systems to pathophysiology and exercise intolerance in pH. Methods: A systematic literature search was conducted using specific terms in PubMed, SciELO, and the Cochrane Library databases for original pre-clinical or clinical studies published between 2013 and 2023. Studies followed randomized controlled/non-randomized controlled and pre-post designs. Results: The systematic review identified 25 articles reporting functional or structural changes in the respiratory, cardiovascular, and musculoskeletal systems in pH. Moreover, altered biomarkers in these systems, lower cardiac baroreflex, and heightened peripheral chemoreflex activity seemed to contribute to functional changes associated with poor prognosis and exercise intolerance in pH. Potential therapeutic strategies acutely explored involved manipulating the baroreflex and peripheral chemoreflex, improving cardiovascular autonomic control via cardiac vagal control, and targeting specific pathways such as GPER1, GDF-15, miR-126, and the JMJD1C gene. Conclusion: Information published in the last 10 years advances the notion that pH pathophysiology involves functional and structural changes in the respiratory, cardiovascular, and musculoskeletal systems and their integration with peripheral reflexes. These findings suggest potential therapeutic targets, yet unexplored in clinical trials, that could assist in improving exercise tolerance and QoL in patients with pH. [Display omitted] [ABSTRACT FROM AUTHOR]

Limited chest expansion and asymmetry in the respiratory muscles after a stroke lead to poor ventilation and reduced physical performance.To determine the effect of chest expansion resistance exercise and respiratory muscle stretching on respiratory function and gait endurance in patients with stroke.Thirty stroke patients were randomly assigned to a chest expansion resistance group (CERG), a respiratory muscle stretching group (RMSG), and a control group (CG). CERG and RMSG received chest expansion resistance and respiratory muscle stretching, respectively, 3 times a week for 8 weeks. Respiratory function, respiratory muscle strength, and gait endurance were measured before and after the intervention period.The experimental groups, CERG and RMSG, showed significant improvements in respiratory function variables (p < .05). For respiratory muscle strength variables, maximal inspiratory pressure (MIP) in the CERG and maximal expiratory pressure (MEP) in the RMSG showed significant changes compared to the CG (p < .05). Both CERG and RMSG also showed significant improvements in the 6MWT compared to the CG (p < .05).Chest expansion resistance exercise would be a more effective method, while both chest expansion resistance exercise and respiratory muscle stretching are helpful in improving respiratory function and gait endurance. [ABSTRACT FROM AUTHOR]

Background: SELENON-related myopathy (SELENON-RM) is a rare congenital myopathy characterized by slowly progressive axial muscle weakness, rigidity of the spine, scoliosis, and respiratory insufficiency. Laminin-a2-related muscular dystrophy (LAMA2-MD) has a similar clinical phenotype, which ranges from severe, early-onset congenital muscular dystrophy type 1A (MDC1A) to milder forms presenting as childhood- or adult-onset limb-girdle type muscular dystrophy. The first 1.5-year natural history follow-up showed that 90% of the patients had low bone quality, respiratory impairments were found in all SELENON-RM and most of the LAMA2-MD patients, and many had cardiac risk factors. However, further extensive knowledge on long-term natural history data, and clinical and functional outcome measures is needed to reach trial readiness. Therefore, we extended the natural history study with 3- and 5-year follow-up visits (Extended LAST STRONG). Methods: The Extended LAST STRONG is a long-term natural history study in Dutch-speaking patients of all ages diagnosed with genetically confirmed SELENON-RM or LAMA2-MD, starting in September 2023. Patients visit our hospital twice over a period of 2 years to complete a 5-year follow up from the initial LAST-STRONG study. At both visits, they undergo standardized neurological examination, hand-held dynamometry (age ≥ 5 years), functional measurements, muscle ultrasound, respiratory assessments (spirometry, maximal inspiratory and expiratory pressure, sniff nasal inspiratory pressure; age ≥ 5 years), Dual-energy X-ray absorptiometry (DEXA-)scan (age ≥ 2 years), X-ray of the left hand (age ≤ 17 years), lower extremity MRI (age ≥ 10 years), accelerometry for 8 days (age ≥ 2 years), and questionnaires (patient report and/or parent proxy; age ≥ 2 years). All examinations are adapted to the patient's age and functional abilities. Disease progression between all subsequent visits and relationships between outcome measures will be assessed. Discussion: This study will provide valuable insights into the 5-year natural history of patients with SELENON-RM and LAMA2-MD and contribute to further selecting relevant and sensitive to change clinical and functional outcome measures. Furthermore, this data will help optimize natural history data collection in clinical care and help develop clinical care guidelines. Trial registration: This study protocol including the patient information and consent forms has been approved by medical ethical reviewing committee ('METC Oost-Nederland'; https://www.ccmo.nl/metcs/erkende-metcs/metc-oost-nederland, file number: 2023–16401). It is registered at ClinicalTrials.gov (NCT06132750; study registration date: 2023-10-05; study first passed date: 2023-11-15). [ABSTRACT FROM AUTHOR]

AbstractPurposeMethodsResultsConclusionsKnowledge gaps exist regarding the effects of interventions due to continuing respiratory symptoms in patients with post-COVID condition. The aim of the present study was to present the clinical outcomes of individualised treatments for patients with remaining respiratory symptoms due to post-COVID condition.This prospective longitudinal study included a consecutive series of 57 patients with remaining respiratory post-COVID symptoms. Breathing pattern, thoracic pain/mobility, occurrence of cough, and respiratory muscle strength were assessed before and after the administration of individually tailored physiotherapy interventions.The median treatment duration was 3 months (range 1–36 months). Dysfunctional breathing pattern was the most common symptom (n = 55/57) at inclusion. After treatment, 95% of patients had a normalised or improved breathing pattern (p < 0.001). The treatments for pain, productive and unproductive cough, and respiratory muscle strength resulted in significantly improved symptoms (p < 0.01). With other targeted treatments, inspiratory muscle strength improved by 20 cmH2O and expiratory muscle strength by 11 cmH2O (both p < 0.001).This study indicates positive outcomes of physiotherapy treatment based on the patient’s symptomatology and test results. Therefore, individualised physiotherapy treatment of post-COVID conditions may have an impact on recovery. [ABSTRACT FROM AUTHOR]

Rationale, Aims and Objectives Method Results Conclusion With absence of a cure, the mainstay of management for patients with motor neurone disease (MND) is holistic supportive care and symptom control. Non‐invasive ventilation (NIV) can provide relief from distressing dyspnoea which often accompanies progressive respiratory muscle weakness. Some patients using NIV will become dependent on it, with a small proportion of these patients going on to request withdrawal. Despite being legal in the UK, elective withdrawal of NIV can be emotionally and ethically challenging for the staff involved. To guide the process of symptom‐controlled withdrawal, in 2015 the Association for Palliative Medicine (APM) released clinical guidance. The aim of this study is to explore the experiences of the multi‐disciplinary team (MDT) involved in elective withdrawal of NIV in an MND cohort following the publication of this guidance.A qualitative, semi‐structured interview study of eight NHS qualified staff members (three Doctors, four Nurses, one Allied Health Professional). Clinicians were asked questions relating to their experiences of the withdrawals. After full transcription, data was analysed thematically.Four main themes were identified, offering insight into how the withdrawals affected staff's well‐being and summarised via an ‘enablers and barriers’ model. The setting was important, as was the depth and longevity of the clinician's investment in the patient. Positive influences on staff's well‐being arose from the sense of fulfilling the patient's wishes, good teamwork, presence of an experienced clinician and awareness of the APM (2015) Guidance. Conversely, barriers to well‐being were expressed through the unpredictability of each scenario, moral and ethical uncertainties, external pressures on time, mismatched expectations, poor communication and the emotional intensity of the act.Elective withdrawal is highly emotive, simultaneously positively and negatively influencing staff well‐being. By addressing the potential mitigating factors, the overall impact on staff's mental health and well‐being maybe improved and thus, subsequently, patient care. [ABSTRACT FROM AUTHOR]

AbstractThere is evidence that substance use and smoking cause some adverse effects on the respiratory system. The aim of this study was to assess dyspnea severity, respiratory muscle strength, cough capacity, and sleep quality in people with substance use disorder (SUD). Forty eight individuals with SUD and 28 active cigarette smokers participated in the study. Participants’ dyspnea severity was assessed using the Modified Medical Research Council Scale, respiratory muscle strength was measured with a portable electronic mouth pressure device, peak cough flow was assessed with a Peak Flow Meter, and sleep quality was determined using the Pittsburgh Sleep Quality Index (PSQI). The amount of daily cigarette smoking and dyspnea severity were significantly higher in individuals with SUD (p < .001). Peak cough flow values, maximum inspiratory pressure (MIP), maximum expiratory pressure (MEP), MIP (%predicted), and MEP (%predicted) were not significantly different between the SUD patients and the active cigarette smokers (p > .05). However, PSQI sub-parameters such as subjective sleep quality, sleep latency, habitual sleep efficiency, use of sleeping medication, and total scores showed significant differences between the SUD patients and the active cigarette smokers (p < .05, p < .001, p = .03, p < .001, p < .001, respectively). Individuals with SUD were found to have higher dyspnea and poorer sleep quality than active smokers. However, respiratory muscle strength and cough capacities were similar. [ABSTRACT FROM AUTHOR]

Background: Animal models focusing on neuromuscular outcomes are crucial for understanding the mechanisms of intensive care unit-acquired weakness (ICU-AW) and exploring potential innovative prevention and treatment strategies. Aim: To analyse and evaluate preclinical ICU-AW models. Methods: We manually searched five English and four Chinese databases from 1 January 2002, to 1 February 2024, and reviewed related study references. Fulltext publications describing animal models of muscle weakness and atrophy in critical illness were included. Detailed information about model types, animal species, sex, age, induction methods, outcome measures, drawbacks and strengths was extracted from each included study. Results: A total of 3,451 citations were initially retrieved, with 84 studies included in the final analysis. The most frequently studied animal model included rodents (86.9%), 64.3% of which were male animals. ICU-AW animal models were mostly induced by comprehensive intensive care unit (ICU) interventions (38.1%) and sepsis (51.2%). Most studies focused on limb muscles (66.7%), diaphragm muscles (21.4%) or both (9.5%). Reported outcomes primarily included muscular pathological changes (83.3%), electrophysiological examinations of muscles (57.1%) and animal grip strength (16.6%). However, details such as animal age, mortality data, experimental design, randomisation, blinding, sample size and interventions for the experimental group and/or control group were inadequately reported. Conclusion: Many preclinical models are used to study ICU-AW, but the reporting of methodological details is often incomplete. Although current ICU animal models can mimic the characteristics of human ICU-AW, there is no standard model. Future preclinical studies should develop a standard ICU-AW animal model to enhance reproducibility and improve scientific rigor in exploring the mechanisms and potential treatment of ICU-AW. [ABSTRACT FROM AUTHOR]

Introduction: Center‐based rehabilitation is limited by COVID‐19 infectivity and social distancing policy. We hypothesized that discharged patients benefit from 8‐week home‐based tele‐rehabilitation (tele‐PR) using mobile phones and low‐cost instruments. Methods: The TERCOV (Tele‐rehabilitation in COVID‐19 survivors) is an investigator‐initiated, prospective, multi‐center, real‐world study. After proper assessment, 186 discharge patients received tele‐PR by smartphone, including breathing exercise, respiratory muscle training, aerobic exercise, and resistance training. Physicians, physiotherapists, and nurses provided guidance through smartphone applications. The primary outcome was six‐minute walk distance (6MWD). The secondary outcomes included hand grip, short physical performance battery, maximal inspiratory pressure, maximal expiratory pressure, self‐rating anxiety/depression scale (SAS/SDS), 36‐item short‐form health survey (SF‐36) and international physical activity questionnaire. Results: Dyspnea subgroups were more functionally impaired. After tele‐PR, improvements were observed in exercise capacity(∆6MWD: 16.80 m, 95% CI 1.18–32.42, p < 0.0001), limb muscle function (∆SPPB 0.25 points, 95% CI 0.05–0.46), respiratory muscle strength (∆MIP 16.50 cm H2O, 95% CI 9.22–23.78, p < 0.0001; ∆MEP: 12.09 cm H2O, 95% CI 3.48–20.70, p = 0.0002), health‐related quality of life (∆SF‐36 49.85, 95% CI: 21.01–78.69, p < 0.0001), physical activity(∆HEPA 13.01%, p = 0.0029). Anxiety reduced in patients with mMRC ≥ 2 (∆SAS = −4.19 points, CI −8.16 to −0.22, p = 0.03). Greater change was seen in dyspnea patients. Implications on Physiotherapy Practice: Supervised/semi‐supervised tele‐PR is a promising option during the pandemic. Patients with Dyspnea benefit more. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Versican is increased with inflammation and fibrosis, and is upregulated in Duchenne muscular dystrophy. In fibrotic diaphragm muscles from dystrophic mdx mice, genetic reduction of versican attenuated macrophage infiltration and improved contractile function. Versican is also implicated in myogenesis. Here, we investigated whether versican modulated mdx hindlimb muscle pathology, where inflammation and regeneration are increased but fibrosis is minimal. Immunohistochemistry and qRT-PCR were used to assess how fiber type and glucocorticoids (α-methylprednisolone) modify versican expression. To genetically reduce versican, female mdx and male versican haploinsufficient (hdf) mice were bred resulting in male mdx-hdf and mdx (control) pups. Versican expression, contractile function, and pathology were evaluated in hindlimb muscles. Versican immunoreactivity was greater in slow versus fast hindlimb muscles. Versican mRNA transcripts were reduced by α-methylprednisolone in soleus, but not in fast extensor digitorum longus, muscles. In juvenile (6-wk-old) mdx-hdf mice, versican expression was most robustly decreased in soleus muscles leading to improved force output and a modest reduction in fatiguability. These functional benefits were not accompanied by decreased inflammation. Muscle architecture, regeneration markers, and fiber type also did not differ between mdx-hdf mice and mdx littermates. Improvements in soleus contractile function were not retained in adult (20-wk-old) mdx-hdf mice. In conclusion, soleus muscles from juvenile mdx mice were most responsive to pharmacological or genetic approaches targeting versican; however, the benefits of versican reduction were limited due to low fibrosis. Preclinical matrix research in dystrophy should account for muscle phenotype (including age) and the interdependence between inflammation and fibrosis. [ABSTRACT FROM AUTHOR]

Cervical septic arthritis can lead to complications such as epidural abscess, which may result in respiratory failure. We present a case of a 78‑year‑old male with cervical septic arthritis complicated by epidural abscess, leading to severe diaphragm dysfunction. Ultrasound evaluation revealed dysfunction of the left hemidiaphragm and compensatory activation of accessory respiratory muscles. Treatment included antibiotic therapy and corticosteroids, alongside respiratory support. After 21 days, improvements were observed in diaphragmatic function and respiratory muscle activation. Our findings highlight the importance of assessing both diaphragm and accessory respiratory muscles in cases of cervical septic arthritis with respiratory complications. [ABSTRACT FROM AUTHOR]

Background: The incremental exercise test is commonly used to measure maximal oxygen uptake (VO2max), but an additional verification test is often recommended as the "gold standard" to confirm the true VO2max. Therefore, the aim of this study was to compare the peak oxygen uptake (VO2peak) obtained in the ramp incremental exercise test and that in the verification test performed on different days at submaximal intensity. Additionally, we examined the roles of anaerobic performance and respiratory muscle strength. Methods: Sixteen physically active men participated in the study, with an average age of 22.7 ± 2.4 (years), height of 178.0 ± 7.4 (cm), and weight of 77.4 ± 7.3 (kg). They performed the three following tests on a cycle ergometer: the Wingate Anaerobic Test (WAnT), the ramp incremental exercise test (IETRAMP), and the verification test performed at an intensity of 85% (VER85) maximal power, which was obtained during the IETRAMP. Results: No significant difference was observed in the peak oxygen uptake between the IETRAMP and VER85 (p = 0.51). The coefficient of variation was 3.1% and the Bland–Altman analysis showed a high agreement. We found significant correlations between the total work performed in the IETRAMP, the anaerobic peak power (r = 0.52, p ≤ 0.05), and the total work obtained in the WAnT (r = 0.67, p ≤ 0.01). There were no significant differences in post-exercise changes in the strength of the inspiratory and expiratory muscles after the IETRAMP and the VER85. Conclusions: The submaximal intensity verification test performed on different days provided reliable values that confirmed the real VO2max, which was not limited by respiratory muscle fatigue. This verification test may be suggested for participants with a lower anaerobic mechanical performance. [ABSTRACT FROM AUTHOR]

The sternohyoid muscle depresses the hyoid bone, but it is unclear whether the muscle contributes to respiratory and swallowing mechanisms. This study aimed to clarify whether the sternohyoid muscle participates in the respiration and swallowing reflex and how the activity is modulated in two conditions: with airway stenosis and with a fixed sternohyoid muscle length. Electromyographic activity in the sternohyoid, digastric, thyrohyoid, and diaphragm muscles was recorded in anesthetized rats. The sternohyoid muscle activity was observed in the inspiratory phase and during swallowing, and was well coordinated with digastric and thyrohyoid muscle activity. With airway stenosis, the respiratory activity per respiratory cycle was facilitated in all assessed muscles but the facilitation of activity per second occurred only in the digastric, thyrohyoid, and sternohyoid muscles. With airway stenosis, the swallowing activity was facilitated only in the digastric muscle but not in the thyrohyoid and sternohyoid muscles. Swallowing activity was not observed in the sternohyoid muscle in the condition with the sternohyoid muscle length fixed, although increased inspiratory activity remained. The current results suggest that 1) the sternohyoid muscle is slightly activated in the inspiratory phase, 2) the effect of airway stenosis on respiratory function may differ between the upper airway muscles and diaphragm, and 3) swallowing activity in the sternohyoid muscle is not dominantly controlled by the swallowing central pattern generator but instead occurs as a myotatic reflex. NEW & NOTEWORTHY: We found that the sternohyoid muscle was activated in the inspiratory phase. However, increased airway resistance had different effects on the extrathoracic muscles than on the diaphragm. The swallowing activity of the sternohyoid disappeared when the muscle length was fixed. These findings suggest that the sternohyoid muscle may be activated not by the swallowing central pattern generator but as a myotatic reflex. [ABSTRACT FROM AUTHOR]

Background: Respiratory muscle training (RMT) aims to improve inspiratory and/or expiratory muscle function in neuromuscular disorders (NMDs). A comprehensive overview of the available literature is lacking. This scoping review explores methodological characteristics, (adverse) effects, and adherence of RMT studies in NMDs. Moreover, it identifies limitations and research gaps in the literature and provides future research directions. Summary: Eligible studies were identified using MEDLINE, Embase, Cochrane Database of Systematic Reviews, and Cochrane Central Register of Controlled Trials databases. Three reviewers independently selected articles. Inclusion criteria were English language, original research articles on RMT using a device, patients with an NMD, and pulmonary function tests or respiratory muscle strength as outcome measures. We included NMDs with slow, intermediate and fast progression. Exclusion criteria were critically ill patients, weaning from mechanical ventilation, other neurological disorders, and RMT combined with non-respiratory interventions. One reviewer extracted the data on patients' characteristics, methodological characteristics, results of outcome measures, adverse events, and patient adherence. Forty-five studies were identified. We found a large diversity in study designs and training protocols. The effects of RMT on respiratory muscle strength and/or endurance are variable. Patient adherence was high and no serious adverse events were reported. Key Messages: The diversity in studies across the available literature precludes definitive conclusions regarding the effects of RMT on respiratory muscle function and clinically relevant outcomes in NMDs. Therefore, well-powered and -designed studies that focus on clinically relevant outcomes and assess whether RMT can improve or offset deterioration of respiratory muscle weakness in NMDs are needed. [ABSTRACT FROM AUTHOR]

Background: Tracheostomy is one of the most common procedures done in intensive care unit (ICU) patients. Decannulation is the weaning off from tracheostomy to maintain spontaneous respiration and/or airway protection. However, this step needs a near perfect coordination of brain, swallowing, coughing, phonation, and respiratory muscles. However, despite its perceived importance, there is no universally accepted protocol for this vital transition. In this systematic review of decannulation we focus attention to this important aspect of tracheostomy care. Aim: To compare the two methods of decannulation, with gradual blocking of the tube and reducing the size of the tube and also study and compare the incidental complications associated with both methods. Methodology: This longitudinal, open label, randomized, observational study of 50 patients who were tracheostomized for more than 7 days was carried out in a tertiary health care Centre in central India. Over the course of 2 years demographic data, clinical information was collected and patients divided into 2 groups according to the method of decannulation done by a simple randomization method. The outcomes and the complications associated with the two techniques in the study groups were also be noted down and then compared. Results: Maximum number of patients in both the study groups were males (56% in group with tube blocking, and 52% in group with tube size reduction). 48% cases in group with tube blocking, and 60% in group with tube size reduction were noted to be between 51 and 70 years' age group. The mean duration between tracheostomy and decannulation in group with tube blocking was 16.63 + 8.44 days, and while it was 16.71 + 8.79 days in group with tube size reduction. 36% patients in group with tube blocking had tracheostomy tube number 7.5, while 32% had tube number 8. 36% in group with tube size reduction had tube number 7.5 while 32% had tube size 7. 4 patients in group with tube blocking, and 3 patients in group with tube size reduction required reinsertion of tube. 40% patients in group with tube blocking, and 44% in group with tube size reduction underwent tracheostomy following prolonged intubation. 4 patients in group with tube blocking, and 3 patients in group with tube size reduction required reinsertion of tube. 1 patient in group with tube blocking had trachea-esophageal fistula as post decannulation complication. 1 patient each in group with tube size reduction had granule formation over stoma and tracheal stenosis as complications. Conclusion: The two decannulation methods, viz., gradual blocking of tube and reduction of tube size, showed comparable outcomes in terms of tube reinsertion rate, mechanical ventilation rate after decannulation, successful decannulation, and complications. [ABSTRACT FROM AUTHOR]

We recently explored the cardiopulmonary interactions during partial unloading of the respiratory muscles during exercise. Expanding upon this work, we present a noteworthy case study whereby we eliminated the influence of respiration on cardiac function in a conscious but mechanically ventilated human during exercise. This human was a young healthy endurance-trained male who was mechanically ventilated during semi-recumbent cycle exercise at 75 Watts (W) (∼30% Wmax). During mechanically ventilated exercise, esophageal pressure was reduced to levels indistinguishable from the cardiac artefact which led to a 94% reduction in the power of breathing. The reduction in respiratory pressures and respiratory muscle work led to a decrease in cardiac output (−6%), which was due to a reduction in stroke volume (−13%), left ventricular end-diastolic volume (−15%), and left-ventricular end-systolic volume (−17%) that was not compensated for by heart rate. Our case highlights the influence of extreme mechanical ventilation on cardiac function while noting the possible presence of a maximal physiological limit to which respiration (and its associated pressures) impacts cardiac function when the power of breathing is maximally reduced. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

• We performed detailed clinical assessments in Dutch nemaline myopathy patients. • Half of the cohort uses a wheelchair and/or mechanical ventilation. • Patients have a reduced experienced quality of life and a high experienced fatigue. • The results provide important recommendations for future trial design. 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. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate the potential of incorporating respiratory muscle strength, specifically maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP), along with traditional sarcopenia screening measures such as hand grip strength (HGS) and skeletal muscle mass index (SMI), to identify sarcopenia in older men. Materials and Methods: A retrospective analysis was conducted involving male patients aged 65 years and older who underwent measurements of respiratory muscle strength, HGS, and muscle mass at a general hospital in Korea from July 2016 to May 2022. Statistical analysis utilized independent t-tests and receiver operating characteristic (ROC) curves to assess the sensitivity and specificity of MIP, MEP, HGS, and SMI in sarcopenia screening. The cut-off values for sarcopenia screening were determined based on the area under the ROC curve (AUC). Results: The analysis of 282 study participants revealed the following cut-off values for sarcopenia based on the AUC: for MIP, the cut-off value was 65.50 cmH2O (AUC=0.70, sensitivity: 0.63, specificity: 0.61), while for MEP, it was 84.50 cmH2O (AUC=0.74, sensitivity: 0.66, specificity: 0.68). Conclusions: This study showed the utility of respiratory muscle strength in screening for sarcopenia among older men. We suggest the screening cut-off values as 65.50 cmH2O for MIP and 84.50 cmH2O for MEP. Even when HGS and SMI measurements are not feasible, sarcopenia can be reasonably predicted based on respiratory muscle strength. [ABSTRACT FROM AUTHOR]

A study published in the journal Diabetes, Obesity & Metabolism examined the effects of a weight-loss program combined with respiratory muscle training (RMT) on weight and cardiovascular risk in adults with obesity. The study found that participants who followed the program experienced significant improvements in weight management and biomarkers, such as blood pressure and blood glucose levels. Compliance with the program was linked to positive outcomes. The study suggests that a combination of portion control and RMT could be an effective approach for weight loss and improving cardiovascular health in individuals with obesity. However, the study had limitations, including a small sample size and lack of a control group. [Extracted from the article]

BACKGROUND: High-flow tracheal oxygen (HFTO) is being used as supportive therapy during weaning in tracheostomized patients difficult to wean from invasive mechanical ventilation. There is, however, no clinical evidence for such a strategy. Therefore, we conducted a systematic review to summarize studies evaluating the physiologic effects of HFTO during tracheostomy-facilitated weaning and to identify potential areas for future research in this field. METHODS: Observational and interventional studies on critically ill subjects weaning from mechanical ventilation via tracheostomy published until December 22, 2022, were eligible. Studies on high-flow oxygen, only in children, non-human models or animals, on clinical outcome only, abstracts without full-text availability, case reports, and reviews were excluded. Main outcomes were end-expiratory lung volume (EELV) and tidal volume using electrical impedance tomography, respiratory effort assessed by esophageal manometry, work of breathing and neuroventilatory drive as assessed by electrical activity of the diaphragm (EAdi) signal, airway pressure (Paw), oxygenation (... or ...), breathing frequency, tidal volume, and .... RESULTS: In total, 1,327 references were identified, of which 5 were included. In all studies, HFTO was administered with flow 50 L/min and compared to conventional O2 therapy in a crossover design. The total average duration of invasive ventilation at time of measurements ranged from 11-27 d. In two studies, ... and mean Paw were higher with HFTO. EELV, tidal volumes, esophageal pressure swings, and EAdi were similar during high-flow tracheal oxygen and conventional O2 therapy. CONCLUSIONS: The main physiological effect of HFTO as compared to conventional O2 therapy in tracheostomized subjects weaning from mechanical ventilation was improved oxygenation that is probably flow-dependent. Respiratory effort, lung aeration, neuroventilatory drive, and ventilation were similar for HFTO and conventional O2 therapy. Future studies on HFTO should be performed early in the weaning process and should evaluate its effect on sputum clearance and patient-centered outcomes like dyspnea. [ABSTRACT FROM AUTHOR]

Collagen fiber architecture within the skeletal muscle extracellular matrix (ECM) is significant to passive muscle mechanics. While it is thought that collagen fibers re-orient themselves in response to changes in muscle length, this has not been dynamically visualized and quantified within a muscle. The goal of this study was to measure changes in collagen alignment across a range of muscle lengths and compare the corresponding alignment to muscle mechanics. We hypothesized that collagen fibers dynamically increase alignment in response to muscle stretching, and this change in alignment is related to passive muscle stiffness. Further, we hypothesized that digesting collagen fibers with collagenase would reduce the re-alignment response to muscle stretching. Using DBA/2J and D2. mdx mice, we isolated extensor digitorum longus (EDL), soleus, and diaphragm muscles for collagenase or sham treatment and decellularization to isolate intact or collagenase-digested decellularized muscles (DCMs). These DCMs were mechanically tested and imaged using second harmonic generation microscopy to measure collagen alignment across a range of strains. We found that collagen alignment increased in a strain-dependent fashion, but collagenase did not significantly affect the strain-dependent change in alignment. We also saw that the collagen fibers in the diaphragm epimysium (surface ECM) and perimysium (deep ECM) started at different angles, but still re-oriented in the same direction in response to stretching. These robust changes in collagen alignment were weakly related to passive DCM stiffness. Overall, we demonstrated that the architecture of muscle ECM is dynamic in response to strain and is related to passive muscle mechanics. Our study presents a unique visualization and quantification of strain-induced changes in muscle collagen fiber alignment as they relate to passive mechanics. Using dynamic imaging of collagen in skeletal muscle we demonstrate that as skeletal muscle is stretched, collagen fibers re-orient themselves along the axis of stretch and increase their alignment. The degree of alignment and the increase in alignment are each weakly related to passive muscle stiffness. Collagenase treatments further demonstrate that the basis for muscle Extracellular matrix stiffness is dependent on factors beyond collagen crosslinking and alignment. Together the study contributes to the knowledge of the structure-function relationships of muscle extracellular matrix to tissue stiffness relevant to conditions of fibrosis and aberrant stiffness. [Display omitted] [ABSTRACT FROM AUTHOR]

Chronic respiratory failure is a common cause of ventilator dependence in the intensive care unit (ICU). The causes of chronic respiratory failure include primary disease or complications, such as ICU-acquired weakness. Traditional practice requires patients to remain immobile and bedridden; however, recent evidence suggests that early adequate exercise promotes recovery without increasing risks. In this study, we explored the efficacy of planned progressive abdominal sandbag training in promoting the successful withdrawal of patients with chronic respiratory failure from mechanical ventilation. This study was conducted between April 2019 and November 2020. Patients were recruited and divided into two groups: abdominal sandbag training group and control group (no training). The training group participated in a 3-month daily pulmonary rehabilitation program, which involved a 30-min session of progressive sandbag loading on the upper abdomen as a form of diaphragmatic resistant exercise. The pressure support level of the ventilator was adjusted to maintain a tidal volume of 8 mL/kg. To investigate the effect of abdominal sandbag training on patients with chronic respiratory failure, we compared tidal volume, shallow breathing index, maximum respiratory pressure, and diaphragm characteristics between the training and control groups. This study included 31 patients; of them, 17 (54.8 %) received abdominal sandbag training and 14 (45.2 %) did not. No significant between-group difference was found in baseline characteristics. Compared with the control group, the training group exhibited considerable improvements in ventilation-related parameters (p < 0.001): the tidal volume markedly increased (p = 0.012), rapid shallow breathing index declined (p = 0.016), and maximum respiratory pressure increased (p < 0.001) in the training group. The diaphragm motion value (p = 0.048) and diaphragm thickness (p = 0.041) were greater in the training group than in the control group. Nine patients (52.9 %) in the training group were removed from the ventilator compared with 1 (7.1 %) in the control group (p = 0.008). Abdominal sandbag training may be beneficial for patients dependent on a ventilator. The training improves the function of the diaphragm muscle, thereby increasing tidal volume and reducing the respiratory rate and rapid shallow breathing index, thus facilitating withdrawal from ventilation. This training approach may also improve the thickness and motion of the diaphragm and the rate of ventilator detachment. [ABSTRACT FROM AUTHOR]

This study explores the association of respiratory muscle strength with aerobic endurance kinetics among athletes, with a specific focus on maximal oxygen consumption (VO2max). Previous research has elucidated the complex interactions between respiratory and skeletal muscles during exercise, highlighting the critical role of efficient respiration in maximizing athletic performance. The interplay between active skeletal muscles and respiratory muscles, especially the influence of respiratory muscle fatigue on exercise capacity, is well-documented. High-intensity exercise has been shown to activate the respiratory muscle metaboreflex, which can restrict blood flow to working muscles, thereby impacting the energy required for respiration. A total of 41 athletes, drawn from the disciplines of biathlon, judo, and cross-country, participated in this study. Respiratory function tests (RFTs) were administered to assess various respiratory parameters, including changes in chest circumference. Additionally, maximal oxygen consumption (VO2max) and heart rate were measured during a treadmill test. To explore the associations between VO2max and ventilatory parameters—namely, ventilation (VE), oxygen consumption (VO2), carbon dioxide production (VCO2)—as well as respiratory metrics, linear regression analysis was employed. Based on the standardized regression coefficients (β), it was found that maximum expiratory pressure (MEP) (mean ± SD: 130.95 ± 42.82) and inspiratory diaphragmatic circumference values were significantly associated with VE, VO2, and VCO2. Conversely, the other predictor variables did not exhibit a significant effect on VE (mean ± SD: 134.80 ± 36.69), VO2 (mean ± SD: 3877.52 ± 868.47 mL), and VCO2 (mean ± SD: 4301.27 ± 1001.07 mL). Similarly, measurements of chest circumference (mean ± SD: 91.40 ± 10.72 cm), MEP, and diaphragmatic circumference during inspiration (mean ± SD: 95.20 ± 10.21 cm) were significantly associated with VO2max (mean ± SD: 58.52 ± 10.74 mL/kg/min), while the remaining predictor variables did not demonstrate a significant effect on VO2max. Additionally, a multiple linear regression analysis was conducted to examine the combined effects of respiratory muscle strength and ventilatory factors on VO2max. The model, which included interaction terms, explained 89.9% of the variance in VO2max (R2 = 0.899, adjusted R2 = 0.859). Significant interactions were found between MIP and VE (B = −0.084, p = 0.006), as well as MEP and VE (B = 0.072, p = 0.012). These findings suggest that respiratory muscle strength plays a more substantial role in determining VO2max in individuals with higher ventilatory efficiency, highlighting the importance of both respiratory strength and breathing efficiency in aerobic performance. Our findings underscore the importance of considering respiratory muscle strength in assessing and enhancing athletes' aerobic performance. Integrating objective measurements such as maximal inspiratory and expiratory pressure assessments into routine performance evaluations allows coaches and sports scientists to monitor changes in respiratory function over time and adjust training protocols accordingly. [ABSTRACT FROM AUTHOR]

Background and purpose Methods Results Conclusions Dysfunction of the airway defence system in Huntington's disease (HD) is a significant but often overlooked problem. Although expiratory muscle strength training (EMST) is frequently utilized in cough effectiveness treatment, its specific impact in HD patients has not yet been explored. This study investigated the effects of EMST on voluntary peak cough flow (vPCF) in HD patients and evaluated the retention of potential gains post‐intervention.In this prospective case‐controlled trial, 29 HD patients completed an 8‐week wait‐to‐start period, which served to identify the natural development of expiratory muscle strength and vPCF. This was followed by 8 weeks of EMST training and an additional 8 weeks of follow‐up. The study's outcome parameters, vPCF and maximum expiratory pressure (MEP), were measured against those of age‐ and sex‐matched healthy controls.Huntington's disease patients had significantly lower MEP (p < 0.001) and vPCF (p = 0.012) compared to healthy controls at baseline. Following the EMST, significant improvements in MEP (d = 1.39, p < 0.001) and vPCF (d = 0.77, p = 0.001) were observed, with HD patients reaching the cough performance levels of healthy subjects. However, these gains diminished during the follow‐up, with a significant decline in vPCF (d = −0.451, p = 0.03) and in MEP (d = −0.71; p = 0.002).Expiratory muscle strength training improves expiratory muscle strength and voluntary cough effectiveness in HD patients, but an ongoing maintenance programme is necessary to sustain the improvements. [ABSTRACT FROM AUTHOR]

Background: This systematic review and meta-analysis aimed to assess the impact of inspiratory muscle training (IMT) on lung function parameters (MIP, MEP, FEV1, and FVC) between both elite and non-elite swimmers. Methods: We searched for controlled clinical trials (CCT) and prospective longitudinal studies (PLS) in elite and non-elite swimmers following an inspiratory muscle training (IMT) protocol with a standardized device, published between 2012 and 2023. The databases used in the search were PubMed, Science Direct, Scopus, Springer, Cochrane Central Register of Controlled Trials, and Google Scholar. The primary outcome assessed was the impact of IMT on lung function parameters, including MIP, MEP, FEV1, and FVC. Results: We selected 13 articles involving 277 subjects aged 11-21 years, with 61.4% being male, and 84.6% being elite swimmers. The most commonly used IMT device was the PowerBreathe®, prescribed for 3-12 weeks, 1-2 sessions per day, 3-6 times per week, with 30 repetitions, starting at 50% of MIP and progressing up to 80%. The meta-analysis showed that IMT was associated with a higher MIP (MD = 29.35 cmH2O, 95% CI: 13.04-45.65 cmH2O, p < 0.01) without affecting FEV1 and FVC. Conclusion: The swimmers that used IMT improved muscle strength, specifically MIP, without changes in MEP, FEV1, and FVC. [ABSTRACT FROM AUTHOR]

Objective To investigate the diagnostic value of skeletal muscle and diaphragm muscle in the extremities, as assessed by bedside ultrasound, for ICU-acquired weakness in elderly patients. Methods A total of 47 elderly patients with severe illness, admitted to the intensive care unit (ICU) of the Second People's Hospital of Yuhang District from March 2023 to April 2024, were included in this study. The average age of the patients was 74.51 years. Medical Research Council (MRC) scores were assessed twice within a 24-hour interval. Among them, when MRC score < 48, 20 cases were classified into the ICU-AW group, while the remaining 27 cases formed the non-ICU-AW group with MRC score ≥ 48. Ultrasound measurements for lower extremity skeletal muscle thickness and diaphragm parameters were conducted on the first day, third day, and seventh day after ICU admission. The rate of shrinkage in upper and lower extremity skeletal muscle thickness at different time points was calculated. Differ- ences in ultrasound parameters between the two groups were compared, and ROC curve analysis was performed to evaluate the diagnostic value of upper and lower extremity skeletal muscle as well as diaphragm parameters for ICU-AW. Results Significant differences were observed in gender, age, BMI, APACHE II score, SOFA score, number of mechanical ventilation cases, and number of sepsis cases between the two groups (P < 0.05). Compared to the non-ICU-AW group, the ICU-AW group exhibited higher rates of atrophy in quadriceps femoris (RF) and total quad- riceps femoris (QF) on day 3 and a lower degree of diaphragm displacement (DE) (P < 0.05). On day 7, the ICU- AW group showed higher rates of atrophy in quadriceps femoris [rectus femoris (RF), intermedius femoris (VI), and total quadriceps femoris (QF)] along with lower diaphragm parameters [diaphragm displacement degree (DE) and diaphragm thickness fraction(DTF)] (P < 0.05). According to ROC curve analysis, the critical value of ICU- AW predicted by ΔRF-MLT atrophy rate on day 7 was 9.9%, AUC was 0.743, sensitivity was 75.0% and specificity was 77.8%. On day 7, the critical value of ICU-AW was 5.69%, AUC was 0.828, sensitivity was 80.0%, and specificity was 77.8%. On day 7, the critical value of ICU-AW was 16.96%, AUC was 0.835, sensitivity was 60.0%, and specificity was 88.9%. On day 7, DE predicted that the critical value of ICU-AW was 1.67 cm, AUC was 0.818, sensitivity was 75.0%, and specificity was 85.2%. On day 7, DTF predicted that the critical value of ICU-AW was 33.96%, AUC was 0.889, sensitivity was 80.0%, and specificity was 85.2%. On day 7, the AUC of ICU-AW was 0.976, the sensitivity was 80.0%, and the specificity was 100%. Conclusion The quadriceps atrophy rate and diaphragm parameters measured by bedside ultrasound can identify and diagnose ICU-AW as early as possible. [ABSTRACT FROM AUTHOR]

Objective To explore the effects of mechanical ventilation and mechanical ventilation combined with phrenic nerve electrical stimulation on the morphology of the phrenic nerve-diaphragm neuromuscular junction in rats. Methods The rats were divided into a control group (CON group, n = 6); an 18-hour mechanical ventilation group (MV group, n = 6); an 18-hour ventilation combined with sham electrical stimulation group (S-MS group, n = 6); and an 18-hour ventilation combined with electrical stimulation group (MS group, n = 6), in which the diaphragm contraction force was detected through the biological signal acquisition system, the stimulation frequency-contraction curve was fitted, and the muscle fatigue index was calculated. The muscle fiber crosssectional area (CSA) of the diaphragm specimen was observed through HE staining; the endplate membrane area of the neuromuscular junction (NMJ) was observed through immunohistochemistry (IHC) staining of the diaphragm combined with laser confocal technology. Results As compared with the CON group, the contractility of isolated diaphragm muscles in the MV group and S-MS group decreased; the fatigue resistance of isolated diaphragm, as compared with the CON group (0.686 8 ± 0.049 42), decreased in the MV group (0.360 3 ± 0.066 89) and the S-MS group (0.367 9 ± 0.034 94), with a greater decline in the MS group (0.536 2 ± 0.054 38); as compared with the CON group [674.3(523.9, 863.6)], diaphragm CSA was reduced in the MV group [374.5(293.3, 522.7)] and S-MS group [392.8(309.5, 542.6)], with a relatively lower reduction in the MS group [592.7(425.1, 820.0)]; as compared with the CON group [393.7(293.5, 471.3)], the diaphragm endplate membrane area decreased in the MV group [289.7(227.0, 354.2)] and S-MS group [243.1(190.8, 331.7)], with a lower degree of reduction in the MS group [331.0(262.8, 413.7). Conclusions Mechanical ventilation causes diaphragm dysfunction in rats and decreases the endplate membrane area of the diaphragm NMJ. Bilateral phrenic nerve electrical stimulation for 10 min/h can improve diaphragm dysfunction and changes in the endplate membrane area of the diaphragm NMJ caused by mechanical ventilation. [ABSTRACT FROM AUTHOR]

Background: This study aimed to investigate the antiparasitic and anti-inflammatory potential of pumpkin seed oil in mice infected with Trichinella spiralis by demonstrating its impact on MMP-9 expression and pathogenesis during the intestinal and muscular phases. Results: In this study, 100 mice were divided into five groups: an infected group, a pumpkin seed oil-treated group (1.5 mg/kg BW, administered three times per week), an albendazole-treated group, a native control group, and a pumpkin oil control group. Gas chromatography–mass spectrometry analysis of the pumpkin seed oil revealed a broad spectrum of biologically active compounds. The pumpkin seed oil treatment led to a significant reduction in the parasite burden, with a 75% decrease in adult worms and a 66% decrease in encysted larvae. Additionally, the infected animals treated with pumpkin oil exhibited a marked reduction in intestinal inflammation, characterized by a progressive increase in goblet cells. The number of encysted larvae in the diaphragm and muscle tissues was also significantly decreased. Furthermore, pumpkin seed oil treatment significantly reduced MMP-9 levels in both intestinal and muscular tissues, highlighting its potential to attenuate inflammation. Conclusion: These findings underscore the effectiveness of pumpkin seed oil as anti-inflammatory and antiparasitic agent. [ABSTRACT FROM AUTHOR]

Respiratory function assessment is crucial in optimizing athletic performance, safeguarding respiratory health, and ensuring athletes can perform at their peak potential while minimizing the risk of respiratory‐related issues. The S‐Index Test is a dynamic evaluation of respiratory muscle strength. However, no comprehensive reference values regarding the S‐Index Test have been reported yet. A total of 597 participants performed the S‐Index Test. They were either well‐trained athletes (WTA), or e‐sports athletes (ESA), or age‐matched controls (AMC) groups. The differences in S‐Index Test results between sexes and for group–sex, and performance calibre tier–sex interactions were examined. The relationships between S‐Index Test results and age, anthropometric indices and training experience were assessed. Reference values for all the groups were provided. Amongst athletes, the highest values were observed in swimmers and rowers, and the lowest in figure skaters and runners. The S‐Index Test results were different for the group–sex interaction (P = 0.004, 151.6 ± 29.0 cmH2O for WTA males and 109.8 ± 21.6 cmH2O for WTA females, 136.7 ± 28.0 cmH2O for ESA males and 101.8 ± 22.0 cmH2O for ESA females, 128.7 ± 28.8 cmH2O for AMC males and 70.3 ± 24.7 cmH2O for AMC females) and higher in males than females (P < 0.001, 145.1 ± 30.5 cmH2O for males and 100.8 ± 27.6 cmH2O for females). The higher athletic level, presented as performance calibre tier, was not linked to higher respiratory muscle strength in the WTA group (P = 0.094). However, the Bonferroni correction revealed that except for the singular tier in females, there was a significant effect for all the other tiers and sexes (P < 0.001). The obtained results confirm that regardless of the level of physical activity, the anthropometric features are positively linked with respiratory muscle strength. Furthermore, age and training experience were positively correlated with the S‐Index Test results in the WTA group. [ABSTRACT FROM AUTHOR]

To observe the effects of ambroxol hydrochloride combined with respiratory muscle strength training on lung function, respiratory muscle strength and serum levels of high mobility group protein 1 (HMGB1), transforming growth factor-ẞ1 (TGF-β1) and serum amyloid A (SAA) in elderly patients with stable stage chronic obstructive pulmonary disease (COPD). Methods: 123 elderly patients with stable stage COPD admitted to our hospital from March 2021 to April 2023 were divided into control group (ambroxol hydrochloride treatment, 61 cases) and observation group (ambroxol hydrochloride combined with respiratory muscle strength training, 62 cases) by random number table method. The efficacy, lung function, respiratory muscle strength, serum HMGB1, TGF-β1, SAA levels and adverse reactions were compared between two groups. Results: Compared with the control group of 78.69%, the clinical total effective rate of the observation group further increased by 93.55% (P<0.05). Compared with control group, the forced expiratory volume in the first second (FEV1), forced vital capacity (FVC), FEV1/FVC, maximum expiratory pressure (MEP) and maximum inspiratory pressure (MIP) were higher in observation group at 2 months after intervention, and HMGB1, TGF-β1, and SAA were lower (P<0.05). There was no difference in the incidence of adverse reactions between two groups (P>0.05). Conclusion: Ambroxol hydrochloride combined with respiratory muscle strength training in the treatment of elderly patients with stable stage COPD, which can effectively improve the clinical treatment effect, improve the lung function and respiratory muscle strength of patients, and regulate the levels of serum HMGB1, TGF-β1 and SAA without increasing the incidence of adverse reactions. [ABSTRACT FROM AUTHOR]

(1) Background: Swallowing disorders are common following a stroke. This study aims to evaluate the effects of a home-based daily intervention focused on inspiratory and expiratory muscle training on swallowing outcomes in patients with chronic stroke. (2) Methods: This manuscript presents the protocol of a single-blind randomized clinical trial. Patients with chronic stroke will be randomly assigned to either an experimental or a control group. The experimental group will undergo daily home-based respiratory muscle training in addition to standard speech and language therapy, while the control group will receive only the standard intervention. The main outcome measures will include the aspiration risk, the strength of respiratory muscles, and peak cough flow. (3) Results: It is hypothesized that patients receiving home-based respiratory training in addition to standard therapy will achieve significant improvements in aspiration risk, respiratory muscle strength, and cough efficacy in comparison with those included in the control group. The results will be published as a manuscript. (4) Conclusions: This study aims to provide evidence on the effectiveness of home-based respiratory muscle training in enhancing swallowing function and respiratory parameters in patients with chronic stroke. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to evaluate the effect of medium-intensity inspiratory muscle training added to standard swimming training on inspiratory muscle strength and aerobic endurance levels and training status in disabled swimming athletes. Methods: This study involved 16 disabled athletes: group I—athletes performing swimming training with 8 weeks inspiratory muscle training—IMT (50% of the maximum inspiratory pressure); group II—athletes performing standard swimming training with 8 weeks inspiratory muscle training (15% MIP). The following tests were performed three times: MIP, MEP, Borg RPE scale and swimming test: T-30 test; 8 × 100 progressive test. Results: There was a significant increase in the MIP and MEP in group I after IMT. There was a significant increase in the distance swam during the T-30 only in group I after IMT. Significant differences were found between the first and third measurements in group I, and the effect was maintained at follow-up. There was also a significant reduction in La concentration in group I after IMT. There was a significant reduction in heart rate at 88% and 93% of the maximum speed in group I after the applied training. Conclusion: Inspiratory muscle training with 50% of the maximum inspiratory pressure load significantly increased the respiratory muscle strength of disabled swimmers. The application of higher-intensity IMT effectively improved the training level and physiological parameters of the swimmers' effort, indicating the need to include this type of training in the standard preparation of disabled swimmers. [ABSTRACT FROM AUTHOR]

Background Methods Results Conclusion Coexistence of chest wall hypomobility and lung hyperinflation compromises respiratory muscle function and respiratory efficiency in people with severe chronic obstructive pulmonary disease (COPD). This study aimed to investigate the effect of chest wall mobilization on functional exercise capacity, respiratory muscle activity and respiratory muscle tissue oxygen saturation for people with severe COPD.Thirty male adults (age: 75 ± 6) diagnosed with severe COPD completed a 6‐week programme (twice/week) according to intervention randomization (chest wall mobilization group, CWMG, n = 15; control group, CG, n = 15). Both groups received standardized education and walking exercise, while CWMG also received chest wall and thoracic spine mobilization. Electromyography of the essential and accessory respiratory muscles and tissue oxygen saturation of the intercostal muscle (StO2, measured by near‐infrared spectroscopy) during incremental cycle exercise test were measured and compared between the two groups at pre‐programme, post‐programme and 3‐month follow‐up.Patients in CWMG demonstrated a significant increase in exercise tolerance from <3 METS to 4–6 METS (p = 0.000) after intervention. A significant decrease in activity of scalene, sternocleidomastoids and intercostal muscle during exercise test (p < 0.01) was found in CWMG, as compared to CG. A significant decrease in StO2 (p < 0.05) and greater decline in the slope of oxygenation dissociation (p = 0.000) were seen in CWMG during exercise test. These positive results were maintained at 3‐month follow‐up in CWMG.Improvements in exercise tolerance, respiratory muscle efficiency and oxygenation extraction ability in CWMG suggest a potential clinical benefit of integrating chest wall and thoracic spine mobilization for rehabilitation of people with severe COPD. [ABSTRACT FROM AUTHOR]

Backgrounds: Chronic obstructive pulmonary disease (COPD) is often ascribed to the disparity that exists between ventilatory loading and diaphragmatic function. The principal factor contributing to this imbalance is the mechanical difficulties brought about by pulmonary hyperinflation. This causes the fiber lengths of the respiratory muscles to be suboptimal, thereby decreasing the tension generated. The frailty of the respiratory musculature is further exacerbated by hypercapnia, acidosis, nutritional deficiency, and steroid therapy. As the principal respiratory muscle, the diaphragm is responsible for 75% of quiescent lung ventilation. Ultrasonography has exhibited substantial promise in evaluating the effectiveness of the diaphragm. The goal of the research was to assess the diaphragmatic function in COPD patients using ultrasonographic examination and to study its correlation with pulmonary function tests. Methods: This work was performed on 60 individuals with COPD and 20 healthy volunteers (control group). All the subjects were sequentially examined by chest X-ray and spirometry in one time and then repeated 15–45 min after the first dose of inhalation therapy (salbutamol); then, 6MWT, ABG, and ultrasonography were done for all patients. Results: In COPD patients, diaphragmatic thickness and excursion were substantially reduced in comparison to the control group; these parameters were also significantly correlated with pulmonary function tests. Conclusions: A reduction in diaphragmatic thickness and excursion is observed in patients diagnosed with COPD. [ABSTRACT FROM AUTHOR]

Introduction: Inspiratory muscle fatigue has been shown to have effects on the autonomic nervous system and physical condition. This study aimed to evaluate the influence of an inspiratory muscle fatigue protocol on respiratory muscle strength and heart rate variability in healthy youths. Materials and Methods: A randomized controlled clinical trial, employing double-blinding, was conducted with twenty-seven participants aged 18-45 years, non-smokers and engaged in sports activity at least three times a week for a minimum of 1 year. Participants were randomly assigned to three groups: Inspiratory Muscle Fatigue group, Activation group, and Control group. Measurements of heart rate variability, diaphragmatic ultrasound, and maximum inspiratory pressure were taken at two stages: before the intervention and immediately after treatment. Results: In our results with respect to baseline to post-treatment, the inspiratory muscle fatigue group showed lower values in the Sniff contraction velocity variable (10.96 cm/s ± 1.99-8.34 cm/s ± 1.23; p < 0.01) and higher values in the activation group (10.59 cm/s ± 0.89-12.66 cm/s ± 1.15; p < 0.01) with respect to the control group (10.27 cm/s ± 1.48-9.97 cm/s ± 1.42). On the other hand, the inspiratory muscle fatigue group showed higher values in the Low frequency variable (49.37 n.u. ± 13.91 to 69.48 n.u. ± 8.22; p < 0.01) and lower values in the activation group (57.92 n.u. ± 8.37 to 41.59 n.u. ± 11.21; p < 0.01) with respect to the control group (50.83 n.u. ± 17.30 to 52.10 n.u. ± 20.64). Additionally, significant correlations were found between respiratory variables and heart rate variability variables. Conclusion: Acute fatigue of the inspiratory musculature appears to negatively impact heart rate variability and inspiratory muscle strength in healthy youths. [ABSTRACT FROM AUTHOR]

Respiratory Distress Syndrome (RDS) remains a significant challenge in neonatal intensive care, particularly in preterm infants who suffer from surfactant deficiency, leading to alveolar collapse, decreased lung compliance, and impaired gas exchange. While conventional mechanical ventilation (CMV) is the current standard of care, it often involves cyclic alveolar recruitment and derecruitment, which can contribute to ventilator-induced lung injury (VILI). Airway Pressure Release Ventilation (APRV) is a mode of ventilation that maintains continuous alveolar recruitment through prolonged high-pressure phases while allowing spontaneous breathing, potentially reducing VILI. This protocol outlines the rationale, initial settings, adjustments, monitoring, and weaning strategies for using APRV to manage RDS in preterm infants. The paper also emphasizes the importance of adjusting Tlow (time at low pressure) to maintain the T-PEFR (peak expiratory flow rate termination point) at 75% with changes in lung compliance to prevent overinflation and underinflation, highlighting the need for further studies to validate APRV's safety, efficacy, and optimal use in this population. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Respiratory muscle training (RMT) improves endurance performance, balance, and ability to repeat high-intensity exercise bouts, providing a rationale to be applied in short-track speedskating. To establish a preferable RMT method for short-track speedskating, the influence of inspiratory pressure threshold loading (IPTL) and voluntary isocapnic hyperpnoea (VIH) on cardiopulmonary indices and athletic performance was investigated. Sixteen elite short-track speedskaters completed 6 weeks of RMT based on IPTL or VIH. Wingate Anaerobic Tests (WAnTs), cardiopulmonary exercise tests (CPETs), spirometry assessments, and on-ice time trials were performed before and after RMT intervention. Repeated measures ANOVA was used to assess the differences between each method's influence. No statistically significant (p > 0.05) differences between RMT methods were found in performance during the WAnT, CPET, or specific on-ice time trials. Spirometry measures were similar between both methods. Significant effects were found for the interaction between maximum breathing frequency during CPET (BFmax) and method (p = 0.009), as well as for the interaction between BFMax, method, and sex (p = 0.040). BFmax decreased for IPTL and increased for VIH. The interaction between method and sex revealed that BFmax increased only in males performing VIH. Our findings suggest that IPTL and VIH lead to analogous effects in the study participants, highlighting a negligible practical disparity in the impact of different RMT methods in elite short-track speedskaters. [ABSTRACT FROM AUTHOR]

Fatigue and dyspnea are the most commonly reported long-term complaints in individuals previously infected with SARS-CoV-2. This study aimed to comprehensively evaluate diaphragm muscle function in post-COVID-19 patients and investigate whether potential diaphragm dysfunction contributes to physical functioning impairment. A total of 46 patients who qualified for pulmonary rehabilitation were examined. Diaphragm muscle function parameters were evaluated using ultrasonography, while the severity of dyspnea, aerobic capacity, and the amount of energy used by the body during physical activity were assessed using the six-minute walk test, mMRC scale, and Metabolic Equivalent Task (MET), respectively. We identified that 69.5% of patients had diaphragm atrophy and 6.5% had diaphragm paralysis. The percentage of atrophy was not related to age, gender, BMI, oxygen therapy usage during the COVID-19 infection course, and disease severity. Patients who experienced cough, fever, and no loss of smell during the COVID-19 course had significantly greater diaphragm inspiratory thickness values, while patients with cough and no smell disorders had a significantly lower percentage of diaphragm atrophy. Diaphragm functional parameters were strongly associated with selected variables of exercise tolerance, such as distance in the six-minute walk test, oxygen saturation levels, fatigue, and exertion on the Borg scale. In conclusion, diaphragm muscle dysfunction is a serious long-term post-COVID-19 consequence and can be viewed as a major contributing factor to prolonged functional impairments. [ABSTRACT FROM AUTHOR]

BACKGROUND: Patients who have been treated with mechanical ventilation for more than 72 hours are susceptible to symptoms such as hypoxia and respiratory muscle fatigue after weaning, which may result in weaning difficulty and delay, as well as an increased incidence of negative emotions such as anxiety and depression. Correct pulmonary rehabilitation exercise technique and timing can improve the weaning success rate, reduce the disability rate, and reduce the incidence of pulmonary infection, as well as reduce medical expenses. OBJECTIVE: This article provides a review of pulmonary rehabilitation interventions for mechanically ventilated patients, searching relevant literature through databases such as CNKI and PubMed, aiming to provide guidance for the successful weaning of mechanically ventilated patients. METHODS: We selected articles related to pulmonary rehabilitation interventions for mechanically ventilated patients from CNKI (China National Knowledge Infrastructure) and PubMed over the years. RESULTS: This article provides a comprehensive review of the research on lung rehabilitation for patients who are mechanically ventilated during the weaning process in an effort to serve as a guide for a successful transition from mechanical ventilation. CONCLUSION: Early pulmonary rehabilitation training can effectively increase the pulmonary function level and ventilation function of patients and reduce the duration of mechanical ventilation and hospitalization, and is an effective, safe, and feasible treatment method. [ABSTRACT FROM AUTHOR]

The diaphragm muscle (DIAm) is the primary inspiratory muscle in mammals. In awake animals, considerable heterogeneity in the electromyographic (EMG) activity of the DIAm reflects varied ventilatory and nonventilatory behaviors. Experiments in awake animals are an essential component to understanding the neuromotor control of breathing, which has especially begun to be appreciated within the last decade. However, insofar as the intent is to study the control of breathing, it is paramount to identify DIAm EMG activity that in fact reflects breathing. Current strategies for doing so in a reproducible, reliable, and efficient fashion are lacking. In the present article, we evaluated DIAm EMG from awake animals using hierarchical clustering across four-dimensional feature space to classify eupneic breathing. Our model, which can be implemented with automated threshold of the clustering dendrogram, successfully identified eupneic breathing with high F1 score (0.92), specificity (0.70), and accuracy (0.88), suggesting that it is a robust and reliable tool for investigating the neural control of breathing. NEW & NOTEWORTHY: The heterogeneity of diaphragm muscle (DIAm) activity in awake animals reflects real motor behavior diversity but makes assessments of eupneic breathing challenging. The present article uses an unsupervised machine learning model to identify eupneic breathing amidst a deluge of different DIAm electromyography (EMG) burst patterns in awake rats. This technique offers a scalable and reliable tool that improves efficiency of DIAm EMG analysis and minimizes potential sources of bias. [ABSTRACT FROM AUTHOR]

After COVID‐19 long term respiratory symptoms and reduced lung function including maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) have been reported. However, no studies have looked at MIP and MEP in all disease groups and the reference materials collection methods differ substantially. We aimed to determine MIP and MEP in individuals after COVID‐19 infection with different disease severity using reference material of healthy control group obtained using the same standardized method. Patients with COVID‐19 were included March 2020–March 2021 at Rigshospitalet, Denmark. MIP and MEP were measured using microRPM. Predicted MIP and MEP were calculated using reference material obtained from 298 healthy adults aged 18–97 years using the same method. In SECURe, 145 participants were measured median 5 months after COVID‐19 diagnosis and of these 16% had reduced MIP and/or MEP. There was reduced spirometry and total lung capacity, but not reduced diffusion capacity in those with abnormal MIP and/or MEP compared with normal MIP and MEP. Of those with reduced MIP and/or MEP at 5 months, 80% still had reduced MIP and/or MEP at 12 months follow‐up. In conclusion, few have reduced MIP and/or MEP 5 months after COVID‐19 and little improvement was seen over time. [ABSTRACT FROM AUTHOR]

Due to an unexpected activation of different zinc (Zn) transporters in a recent prospective clinical study, we have revisited the role of Zn homeostasis and the activation of matrix metalloproteinases (MMPs) in skeletal muscle exposed to the intensive care unit (ICU) condition (immobilization and mechanical ventilation). ICU patients exposed to 12 days ICU condition were followed longitudinally with six repeated muscle biopsies while they showed a progressive preferential myosin loss, i.e., the hallmark of Critical Illness Myopathy (CIM), in parallel with the activation of Zn-transporters. In this study, we have revisited the expression of Zn-transporters and the activation of MMPs in clinical as well as in experimental studies using an established ICU model. MMPs are a group Zn-dependent endopeptidases which do not only target and cleave extracellular proteins but also intracellular proteins including multiple sarcomeric proteins. MMP-9 is of specific interest since the hallmark of CIM, the preferential myosin loss, has also been reported in dilated cardiomyopathy and coupled to MMP-9 activation. Transcriptional activation of Zn-transporters was observed in both clinical and experimental studies as well as the activation of MMPs, in particular MMP-9, in various limb and respiratory muscles in response to long-term exposure to the ICU condition. The activation of Zn-transporters was paralleled by increased Zn levels in skeletal muscle which in turn showed a negative linear correlation with the preferential myosin loss associated with CIM, offering a potential intervention strategy. Thus, activation of Zn-transporters, increased intramuscular Zn levels, and activation of the Zn-dependent MMPs are forwarded as a probable mechanism involved in CIM pathophysiology. These effects were confirmed in different rat strains subjected to a model of CIM and exacerbated by old age. This is of specific interest since old age and muscle wasting are the two factors most strongly associated with ICU mortality. [Display omitted] • An upregulation of Zn transporters in limb, respiratory and postural muscles in response to the ICU condition and an increased intramuscular Zn content. • An upregulation of the Zn-dependent matrix metalloproteinases (MMPs) in response to the ICU condition. • MMP-9 was upregulated in both rats and patients exposed to the ICU condition offering a potential mechanism underlying the preferential myosin loss associated with Critical Illness Myopathy (CIM) and supported by a negative linear correlation between the preferential myosin loss and intramuscular Zn levels. • Seven common genes involved in Zn ion homeostasis and activation of metalloproteinases were activated similarly in ICU patients and two different rat strains in response to immobilization and mechanical ventilation suggesting their pivotal role in CIM pathophysiology. • A robust downregulation of Pax7 in clinical and experimental studies in response to the ICU condition suggests an early impairment of myogenesis. [ABSTRACT FROM AUTHOR]

Respiratory muscle function is compromised in children recovering from chest wall burns, which potentially leads to more impact on exercise capacity and quality of life. This study investigates the effects of an inspiratory muscle training intervention accompanied with a pulmonary rehabilitation program on respiratory muscle strength, lung function, functional capacity, and quality of life in chest burned children. Forty children with burns, aged from 10 to 18 years old and total body surface area of 30% to 50%, were randomly allocated to the inspiratory muscle training group (IMT- G: n = 20) or control group (CG: n = 20). They received IMT plus pulmonary rehabilitation or pulmonary rehabilitation with sham IMT, respectively for eight weeks. The outcomes were the respiratory muscle strength measured by maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP); lung functions (FEV1, FVC and FEV1/FVC ratio); functional capacity as well as Pediatric Quality of Life to measure physical and psychosocial functioning. outcome measures were assessed at before and after intervention (after eight weeks). Based on the pre-intervention assessments, we found no significant difference between both groups (p > 0.05). Significant post-intervention differences were reported between both groups in MIP (P =.003), MEP (P =.017), FVC (P =.001), FEV 1 (P =.007), FEV 1 /FVC ratio (P =.028), functional capacity (P =.003), physical domain of QoL (P =.006) and psychological domain of QoL (P =.002) in favor of the IMT group. Eight weeks of inspiratory muscle training combined with pulmonary rehabilitation program improved children with chest burns' respiratory muscles strength, lung functions, functional capacity, and quality of life. Inspiratory muscle training may be employed in burn rehabilitation programs. It is a safe and effective therapy in chest burned children. • Inspiratory muscle training with pulmonary rehab improved respiratory muscle strength, lung functions. • Quality of life significantly improved with inspiratory muscle training. • Inspiratory muscle training can be used in burn rehab programs as a safe and effective therapy. [ABSTRACT FROM AUTHOR]

Duchenne muscular dystrophy (DMD) is a fatal genetic neuromuscular disease. Lack of dystrophin in skeletal muscles leads to intrinsic weakness, injury, subsequent degeneration and fibrosis, decreasing contractile function. Dystropathology eventually presents in all inspiratory and expiratory muscles of breathing, severely curtailing their critical function. In people with DMD, premature death is caused by respiratory or cardiac failure. There is an urgent need to develop therapies that improve quality of life and extend life expectancy in DMD. Surprisingly, there is a dearth of information on respiratory control in animal models of DMD, and respiratory outcome measures are often limited or absent in clinical trials. Characterization of respiratory performance in murine and canine models has revealed extensive remodelling of the diaphragm, the major muscle of inspiration. However, significant compensation by extradiaphragmatic muscles of breathing is evident in early disease, contributing to preservation of peak respiratory system performance. Loss of compensation afforded by accessory muscles in advanced disease is ultimately associated with compromised respiratory performance. A new and potentially more translatable murine model of DMD, the D2.mdx mouse, has recently been developed. Respiratory performance in D2.mdx mice is yet to be characterized fully. However, based on histopathological features, D2.mdx mice might serve as useful preclinical models, facilitating the testing of new therapeutics that rescue respiratory function. This review summarizes the pathophysiological mechanisms associated with DMD both in humans and in animal models, with a focus on breathing. We consider the translational value of each model to human DMD and highlight the urgent need for comprehensive characterization of breathing in representative preclinical models to better inform human trials. What is the topic of this review?We review current understanding of the respiratory phenotype in Duchenne muscular dystrophy (DMD), a fatal genetic neuromuscular disease.What advances does it highlight?Diaphragm muscle dystropathology and contractile dysfunction present early in dystrophic disease, yet respiratory system performance is maintained by compensatory mechanisms until late‐stage advanced disease. Loss of compensation afforded by accessory muscles of breathing contributes to respiratory morbidity in canine and murine models of DMD, mirroring the human disease. The D2.mdx mouse appears convenient for the study of the complex respiratory phenotype associated with dystrophin deficiency, and assessments of new therapeutics in this model might be translatable to human DMD. [ABSTRACT FROM AUTHOR]