Respiratory Muscle Function Tests and Diaphragm Ultrasound Predict Nocturnal Hypoventilation in Slowly Progressive Myopathies

Introduction: In slowly progressive myopathies, diaphragm weakness early manifests through sleep-related hypoventilation as reflected by nocturnal hypercapnia. This study investigated whether daytime tests of respiratory muscle function and diaphragm ultrasound predict hypercapnia during sleep.Methods: Twenty-seven patients with genetic myopathies (myotonic dystrophy type 1 and 2, late-onset Pompe disease, facioscapulohumeral dystrophy; 48 ± 11 years) underwent overnight transcutaneous capnometry, spirometry, measurement of mouth occlusion pressures, and diaphragm ultrasound.Results: Sixteen out of 27 patients showed nocturnal hypercapnia (peak ptcCO2 ≥ 50 mmHg for ≥ 30 min or increase in ptcCO2 by 10 mmHg or more from the baseline value). In these patients, forced vital capacity (FVC; % predicted) and maximum inspiratory pressure (MIP; % of lower limit or normal or LLN) were significantly reduced compared to normocapnic individuals. Nocturnal hypercapnia was predicted by reduction in FVC of <60% [sensitivity, 1.0; area under the curve (AUC), 0.82] and MIP (%LLN) <120% (sensitivity, 0.83; AUC, 0.84), the latter reflecting that in patients with neuromuscular disease, pretest likelihood of abnormality is per se higher than in healthy subjects. Diaphragm excursion velocity during a sniff maneuver excluded nocturnal hypercapnia with high sensitivity (0.90) using a cutoff of 8.0 cm/s.Conclusion: In slowly progressive myopathies, nocturnal hypercapnia is predicted by FVC <60% or MIP <120% (LLN). As a novelty, nocturnal hypercapnia can be excluded with acceptable sensitivity by diaphragm excursion velocity >8.0 cm/s on diaphragm ultrasound.

Multislice Spiral CT Image Analysis and Meta-Analysis of Inspiratory Muscle Training on Respiratory Muscle Function

Respiratory muscle function has a significant effect on stroke. Stroke is one of the most common cardiovascular and cerebrovascular diseases in the clinic and has a significant impact on the quality of life of patients. Hemiplegia, cerebral hemorrhage, and even death can occur, mainly in the elderly. In this paper, we meta-analyzed the effect of inspiratory muscle training on respiratory muscle function. In this article, we used a topic search method to search for relevant literature on respiratory muscle training and obtained 58 and 32 literature studies from CNKI and Wanfang Data, respectively. As a result of the screening, 36 and 28 documents were obtained. In this paper, 64 selected articles were studied. The authors make statistics on the literature of designing serum content index and multislice spiral CT (Member of the Society of Cardiological Technicians) image of patients, so as to analyze the influence of CT image and inspiratory muscle training on respiratory muscle function. The study showed that FVC, FEV1, MIP, and diaphragm mobility of the experimental group were significantly improved after treatment in more than 85% of the studies ( P < 0.05 ), while those of the control group were not significantly improved ( P > 0.05 ). The comparison between the two groups after treatment showed that FVC, FEV1, MIP, and diaphragm mobility of the experimental group were higher than those of the control group ( P < 0.05 ). The application of multislice spiral CT image analysis technology can effectively evaluate the effect of inspiratory muscle training on respiratory dysfunction in stroke patients, the mechanism of which regulates the expression of related pathways, suppresses the inflammatory response, and can reduce oxidative stress damage. Therefore, respiratory muscle training can improve the function of respiratory muscle and reduce the death rate of cerebellar hemorrhage in patients with stroke and other vascular diseases.

Respiratory muscle function in the newborn: a narrative review

Our aim was to summarise the current evidence and methods used to assess respiratory muscle function in the newborn, focusing on current and future potential clinical applications. The respiratory muscles undertake the work of breathing and consist mainly of the diaphragm, which in the newborn is prone to dysfunction due to lower muscle mass, flattened shape and decreased content of fatigue-resistant muscle fibres. Premature infants are prone to diaphragmatic dysfunction due to limited reserves and limited capacity to generate force and avoid fatigue. Methods to assess the respiratory muscles in the newborn include electromyography, maximal respiratory pressures, assessment for thoraco-abdominal asynchrony and composite indices, such as the pressure–time product and the tension time index. Recently, there has been significant interest and a growing body of research in assessing respiratory muscle function using bedside ultrasonography. Neurally adjusted ventilator assist is a novel ventilation mode, where the level of the respiratory support is determined by the diaphragmatic electrical activity. Prolonged mechanical ventilation, hypercapnia and hypoxia, congenital anomalies and systemic or respiratory infection can negatively impact respiratory muscle function in the newborn, while caffeine and synchronised or volume-targeted ventilation have a positive effect on respiratory muscle function compared to conventional, non-triggered or pressure-limited ventilation, respectively. Impact Respiratory muscle function is impaired in prematurely born neonates and infants with congenital anomalies, such as congenital diaphragmatic hernia. Respiratory muscle function is negatively affected by prolonged ventilation and infection and positively affected by caffeine and synchronised compared to non-synchronised ventilation modes. Point-of-care diaphragmatic ultrasound and neurally adjusted ventilator assist are recent diagnostic and therapeutic technological developments with significant clinical applicability.

How Breathing Exercises Influence on Respiratory Muscles and Quality of Life among Patients with COPD? A Systematic Review and Meta-Analysis

Aim. This systematic review aimed to investigate the effect of different breathing exercises on respiratory muscle function, 6-minute walk test (6MWT), and quality of life (QoL) in patients with chronic obstructive pulmonary disease (COPD). Methods. We searched online databases including PubMed, Embase, Web of Science, Cochrane Library, and Ovid for randomized controlled trials that assessed the efficacy of breathing exercises on patients with COPD. Patient outcome parameters included changes in respiratory muscle function, 6MWT, and QoL. The Cochrane Collaboration tool was used to assess the risk of bias for each included study. Subgroup analyses concerning different interventions and outcome measurements were conducted as necessary. PROSPERO registration number is CRD42018118367. Results. A total of 17 studies were included for final analysis. Meta-analysis based on the relevant studies showed that breathing exercises had a significant total effect on pulmonary function PImax (mean difference (MD) = 8.65, 95% confidence interval (CI) 3.13–14.16, P = 0.002 ), as well as 6MWT (MD = 27.70, 95% CI 5.45–49.94, P = 0.01 ) in patients with COPD. Conclusions. This systematic review summarized the use of breathing exercises for treating patients with COPD. Breathing exercises were found to be an effective tool for treating patients with COPD by improving inspiratory muscle strength and 6MWT. However, breathing exercises showed no significant improvements on the QoL of patients with COPD.

A review of respiratory manifestations and their management in Ehlers-Danlos syndromes and hypermobility spectrum disorders

Background: Ehlers-Danlos Syndromes (EDS) and Hypermobility Spectrum Disorders (HSD) are a heterogeneous group of heritable genetic connective tissue disorders with multiple characteristics including joint hypermobility, tissue fragility, and multiple organ dysfunction. Respiratory manifestations have been described in EDS patients, but have not been systematically characterized. A narrative review was undertaken to describe the respiratory presentations and management strategies of individuals with EDS and HSD. Methods: A broad literature search of Medline, Embase, Cochrane Database of Systematic Reviews, and Cochrane CENTRAL was undertaken from inception to November 2020 of all study types, evaluating EDS/ HSD and pulmonary conditions. This narrative review was limited to adult patients and publications in English. Results: Respiratory manifestations have generally been described in hypermobile EDS (hEDS), classical and vascular EDS subtypes. Depending on EDS subtype, they may include but are not limited to dyspnea, dysphonia, asthma, sleep apnea, and reduced respiratory muscle function, with hemothorax and pneumothorax often observed with vascular EDS. Respiratory manifestations in HSD have been less frequently characterized in the literature, but exertional dyspnea is the more common symptom described. Respiratory symptoms in EDS can have an adverse impact on quality of life. The respiratory management of EDS patients has followed standard approaches with thoracotomy tubes and pleurodesis for pleural manifestations, vocal cord strengthening exercises, continuous positive pressure support for sleep apnea, and exercise training. Reduced respiratory muscle function in hEDS patients responds to inspiratory muscle training. Conclusion: Respiratory symptoms and manifestations are described in EDS and HSD, and have generally been managed using conservative non-surgical strategies. Research into the prevalence, incidence and specific respiratory management strategies in EDS and HSD is needed to mitigate some of the associated morbidity.