Cough Assistance Research Articles

Adaptive control of airway pressure during the expectoration process in a cough assist system

Existing Mechanical Insufflation-Exsufflation (MI-E) devices often overlook the impact of cough airflow pressure on mucus clearance, particularly lacking in control over airway pressure during the expiratory phase, which can lead to airway collapse and other types of airway damage. This study optimizes the design of cough assist system and explores the effectiveness of PID and adaptive control methods in regulating airway pressure. The adaptive control method compensates for hose pressure drop by online estimation of the ventilatory hose characteristics. It achieves precise tracking of target pressure and ensures the generation of peak flow rates effective for mucus clearance, even in the absence of known patient lung physiological states and unknown hose leakage parameters. Through a series of comparative experiments, this paper confirms the significant advantages of adaptive control in reducing oscillations and overshoot, capable of more stable and precise airway pressure adjustments. This improved control strategy not only enhances clinical safety but also significantly improves therapeutic outcomes and reduces the risk of complications. The findings indicate that the revamped cough assist system, employing an adaptive control strategy, can effectively prevent airway damage during assisted coughing, offering a safer and more effective sputum clearance solution for critically ill patients with expectoration disorders.

Lung volume recruitment and airway clearance for children at home in France

BackgroundAirway clearance (ACT) and lung volume recruitment (LVR) techniques are used to manage bronchial secretions, increase cough efficiency and lung/chest wall recruitment, to prevent and treat respiratory tract infections. The aim of the study was to review the prescription of ACT/LVR techniques for home use in children in France. MethodsAll the centers of the national pediatric noninvasive ventilation (NIV) network were invited to fill in an anonymous questionnaire for every child aged ≤20 years who started a treatment with an ACT/LVR device between 2022 and 2023. The devices comprised mechanical in-exsufflation (MI-E), intermittent positive pressure breathing (IPPB), intrapulmonary percussive ventilation (IPV), and/or invasive mechanical ventilation (IMV)/NIV for ACT/LVR. ResultsOne hundred and thirty-nine patients were included by 13 centers. IPPB was started in 83 (60 %) patients, MI-E in 43 (31 %) and IPV in 30 (22 %). No patient used IMV/NIV for ACT/LVR. The devices were prescribed mainly by pediatric pulmonologists (103, 74 %). Mean age at initiation was 8.9 ± 5.6 (0.4–18.5) years old. The ACT/LVR devices were prescribed mainly in patients with neuromuscular disorders (n = 66, 47 %) and neurodisability (n = 37, 27 %). The main initiation criteria were cough assistance (81 %) and airway clearance (60 %) for MI-E, thoracic mobilization (63 %) and vital capacity (47 %) for IPPB, and airway clearance (73 %) and repeated respiratory exacerbations (57 %) for IPV. The parents were the main carers performing the treatment at home. ConclusionsIPPB was the most prescribed technique. Diseases and initiation criteria are heterogeneous, underlining the need for studies validating the indications and settings of these techniques.

Perioperative Management in Neuromuscular Diseases: A Narrative Review.

Patients with neuromuscular diseases are particularly vulnerable in the perioperative period to the development of pulmonary and cardiac complications, or medication side effects. These risks could include hypoventilation, aspiration pneumonia, exacerbation of underlying cardiomyopathy, arrhythmias, adrenal insufficiency, prolonged neuromuscular blockade, issues related to thermoregulation, rhabdomyolysis, malignant hyperthermia, or prolonged mechanical ventilation. Interventions at each of the perioperative stages can be implemented to mitigate these risks. A careful pre-operative evaluation may help identify risk factors so that appropriate interventions are initiated, including cardiology consultation, pulmonary function tests, initiation of noninvasive ventilation, or implementation of preventive measures. Important intraoperative issues include positioning, airway and anesthetic management, and adequate ventilation. The postoperative period may require correction of electrolyte abnormalities, control of secretions with medications, manual or mechanical cough assistance, avoiding the risk of reintubation, judicious pain control, and appropriate medication management. The aim of this review is to increase awareness of the particular surgical challenges in this vulnerable population, and guide the clinician on the various evaluations and interventions that may result in a favorable surgical outcome.

Effect of Cough Assist Device on Hemodynamic Status and Oxygen Saturation for Ventilated Children

Effect of Cough Assist Device on Hemodynamic Status and Oxygen Saturation for Ventilated Children

Clinical Profile and Outcome of Children Using Mechanical Insufflation Exsufflation Device (Cough Assist) at a Tertiary Care Hospital in Bangalore, India

Abstract Background and Objective: Children with neuromuscular disorders (NMDs) face a higher risk of recurrent pneumonias. Mechanical insufflation–exsufflation (MI-E) is a technique designed to enhance cough effectiveness, improve mucus clearance, and ultimately enhance lung health by boosting expiratory airflow and cough peak flow in coordination with a cough. We assessed the safety and adverse effects of MI-E in our cohort. Materials and Methods: This retrospective study was conducted over a period of 1.5 years at a tertiary care hospital in Bangalore, South India. Children between 1 and 18 years of age were included in the study. The demographic details of each child were collected from hospital records, along with the indication for starting MI-E and the duration of usage of MI-E. Results: Thirty-three children (18 boys) were started on MI-E. The most common indication was spinomuscular atrophy. Before the start of MI-E, 30 children were on noninvasive ventilation and 13 had a tracheostomy. The median insufflation and exsufflation pressures used were in the range of +15 to 25 cm H2O and −15 to −25 cm H20, respectively. Auto mode was used in all the cases, and 28 children used it on a long-term basis. There was a decrease in the frequency of hospitalization (especially in children with NMD). Adherence was very good without any evidence of barotrauma or any other complications. Conclusions: We found that the MI-E device is a valuable tool for aiding airway clearance in children with NMDs. Its use not only prevents intensive care unit admissions, reducing hospital stay duration but many times mitigates the need for hospital admissions altogether.

Cardiomyopathy as cause of death in Duchenne muscular dystrophy: a longitudinal observational study.

Cardiomyopathy has become an important life-limiting factor since survival in Duchenne muscular dystrophy (DMD) has greatly increased with long-term ventilation and cough assistance. The aim of this study was to investigate the association between impaired left ventricular ejection fraction (LVEF) and survival. In a >20-year observational study in patients with DMD (age ≥16 years) with at least three echocardiograms, the association between LVEF and survival and time to cardiac or non-cardiac death was investigated using Kaplan-Meier survival analysis and Cox regression (for LVEF). In 67 DMD patients (430 echocardiograms), the decrease in LVEF over a mean±sd follow-up period of 9.1±5.1 years was -10.0±13.9% absolute, but LVEF progression varied widely. 84% were receiving an angiotensin-converting enzyme inhibitor and 54% a β-blocker at last follow-up with an LVEF of 37.5±12.4% at that time-point. Median (interquartile range) survival was 33 (25-40) years. 28 out of 67 (42%) of the cohort had died and LVEF was a significant negative predictor of survival (hazard ratio 0.95 (95% CI 0.91-0.99); p<0.007). Those who died of cardiac death (53% of known causes of death) had significantly lower LVEF at the time of death (LVEF -11.0% (95% CI -21.1- -0.9%); p=0.035) compared with non-cardiac death and tended to die at a younger age. Cardiomyopathy with systolic heart failure is the leading cause of death and lower LVEF is an independent predictor of mortality at younger ages in patients with DMD. Patients with DMD appear to be undertreated with respect to heart failure drug therapy.

User-perceived impact of long-term mechanical assisted cough in paediatric neurodisability.

To (1) compare the perceived benefit of long-term mechanical insufflation-exsufflation (MI-E) of children with neuromuscular disorders (NMDs) and central nervous system (CNS) disorders, including health care needs and treatment routines and (2) describe the children's health-related quality of life (HRQoL). This cross-sectional study used a questionnaire and memory card data to assess the perceived benefit of MI-E via the Visual Analogue Scale (VAS; 10 maximum), willingness to pause treatment, level of health care needs before and after MI-E initiation, and the children's treatment routines. A DISABKIDS questionnaire assessed HRQoL (100 maximum). Seventy-three children using MI-E participated (42 males, median [interquartile range {IQR}] age 10 years 2 months [6 years 3 months-14 years 1 month]), 47 with NMDs (such as spinal muscular atrophy and Duchenne muscular dystrophy) and 26 with CNS disorders (such as cerebral palsy, encephalitis, neurometabolic and other diseases). The median (IQR) VAS score for the perceived benefit of MI-E therapy at stable state and respiratory tract infection were 9 (6-10) and 10 (8.5-10) respectively. Sixty-two per cent were reluctant or unwilling to pause MI-E therapy, with no NMD versus CNS disorder group difference. After MI-E initiation, fewer physician consultations and hospitalizations were reported by the group with NMDs. The MI-E routine was similar in both groups. The mean (SD) HRQoL score for 26 of 51 eligible children was 71 (16.7). MI-E treatment was generally perceived as beneficial and performed equally in both diagnostic groups. HRQoL was in line with children with a moderate-to-severe chronic condition. Mechanical insufflation-exsufflation (MI-E) was generally perceived as beneficial by the children and parents. The reported benefit of MI-E was higher among daily than sporadic MI-E users. The MI-E treatment routine did not differ between diagnostic groups. The health-related quality of life in this neuropaediatric population was in line with that of children with other moderate-to-severe chronic conditions.

Non-invasive Ventilation to Provide a More Positive Outlook in Neuromuscular Disease: An Update on the CHEST Guidelines

In this editorial, the American College of Chest Physicians (CHEST) guidelines for the respiratory management of patients with neuromuscular disease are discussed. The importance of personalizing treatment to the patient by using specific modalities of non-invasive ventilation is discussed, with emphasis on its benefits and the endpoints of successful treatment and the management of bulbar symptoms, such as secretion management and cough assistance. Finally, disease monitoring and the management of expectations throughout the course of the disease are explored.

Waveforms Analysis in Patients With Amyotrophic Lateral Sclerosis for Enhanced Efficacy of Mechanically Assisted Coughing.

Effectiveness of mechanical assisted coughing with insufflation-exsufflation (MI-E) in amyotrophic lateral sclerosis (ALS) depends largely on severity of bulbar dysfunction, which can generate different upper-airway responses. The aim of the study was to evaluate the use of graphs generated by MI-E in ALS to detect airway obstruction and set parameters to achieve an effective mechanically assisted coughing. This was a prospective study enrolling patients with ALS. Several sessions with MI-E were applied, administering different insufflation-exsufflation (± 20, ± 30, ± 40, ± 50 cm H2O) levels in each session. The graphs produced were recorded and analyzed, and the results were used to select the parameters resulting in more effective MI-E. Sixty-nine subjects with ALS were included, yielding a total of 351 analyzed records. A pattern of obstruction during insufflation was detected in 34 subjects (50.7%) and of upper-airway collapse during exsufflation in 18 subjects (26%). The variable associated with obstruction during insufflation was bulbar upper motor neuron dysfunction (odds ratio 7.19 [95% CI 2.32-22.29], P = .001), whereas bulbar lower motor neuron dysfunction was related to upper-airway collapse during exsufflation (odds ratio 0.32 [95% CI 0.11-0.98], P = .046). After parameters were adjusted, in 68 subjects (98.55%) an effective MI-E was achieved. The only variable that predicted absence of alterations in the graphs was Norris bulbar score (odds ratio 0.87 [95% CI 0.78-0.96], P = .007). Analysis of graphics generated by applying MI-E in ALS was an effective method to detect upper-airway responses and select optimal set parameters. Obstruction during insufflation is related to bulbar upper motor neuron dysfunction and collapse during exsufflation to bulbar lower motor neuron dysfunction.

Multiple breath washout lung function reveals ventilation inhomogeneity unresponsive to mechanical assisted cough in patients with neuromuscular disease

BackgroundRespiratory involvement defines the clinical outcome of neuromuscular diseases (NMD). The lung clearance index (LCI) is a marker of lung ventilation inhomogeneity and indicates small airway disease. It is determined by mulitple breath washout lung function (MBW). The merit of LCI is undisputed for primary lung diseases like cystic fibrosis, but its role in NMD is unclear.MethodsWe investigated the role of MBW in patients with NMD and the effect of two different tracer gases and cough assist devices on the LCI. Patients and controls performed MBW with nitrogen (N2) and sulfur hexafluoride (SF6), whereas the latter analysis was repeated after the use of a cough assist device in the NMD group. LCI was compared to forced vital capacity (FVC) and peak cough flow (PCF).Results24 NMD patients (12 Duchenne Muscular Dystrophy, 8 Spinal Muscular Atrophy, 4 other NMDs) and 15 healthy controls were enrolled. In the NMD group, overall LCI N2 was higher than LCI SF6 (9.67 ± 1.56 vs. 8.71 ± 1.47; mean ± SD; p < 0.033). In controls, LCI N2 did not differ significantly from LCI SF6 (7.03 ± 0.37 vs. 7.05 ± 0.67; p = 0.882). Both LCI N2 and LCI SF6 were significantly higher in NMD patients as in controls (9.67 ± 1.56 vs. 7.03 ± 0.37, p < 0.001, and 8.71 ± 1.478.65 vs. 7.05 ± 0.67, p < 0.001). In the NMD group, both LCI N2 and LCI SF6 showed a negative correlation to FVC (r = − 0.525; p = 0.008 and r = − 0.526; p = 0.008, respectively) and PCF (r = − 0.590; p = 0.002 and r = − 0.641; p = 0.001, respectively). LCI N2 and LCI SF6 correlated well in the NMD group. LCI SF6 did not change significantly after the use of the cough assist in NMD patients (n = 22; 8.65 ± 1.52 pre vs. 8.79 ± 2.03 post, p = 0.667).ConclusionLung involvement of patients with neuromuscular diseases goes beyond weakness of respiratory muscles. MBW with both N2 and SF6 is suitable to detect ventilation inhomogeneity in NMD patients with respiratory impairment. Cough assist devices with low to moderate pressure levels do not immediately improve the LCI.

Impact of SARS-CoV-2 Infection Among Non-Invasive Ventilated ALS Patients

The impact of SARS-CoV-2 infection among neuromuscular diseases with respiratory involvement, including amyotrophic lateral sclerosis (ALS), is still to be elucidated. We aim to characterize the clinical outcome of ALS patients non-invasive ventilated (NIV), following SARS-CoV-2 infection. We analyzed retrospectively our patients followed regularly at our ALS clinic, from the beginning of the COVID-19 pandemic (middle March 2020) to March 2021. We included patients on NIV with a documented SARS-CoV-2 infection. We recorded demographic and clinical data, including from the acute infectious illness. Three men with spinal-onset ALS are described, mean age of onset was 55±9.1 years (45-61), and mean disease duration was 17.5±15.9 months (6.1-41). All of them were wheelchair-bounded, with a mean ALSFRS-R of 15.3±0.6 (15-16). One patient used NIV 15 hours/day, 2 between 4 to 7 hours/day, and all used assisted coughing twice daily. None had coexistent comorbidities. They were managed for SARS-CoV-2 infection as outpatients with fluticasone, bronchodilators, azithromycin and increasing frequency of assisted coughing. Supplemental oxygen (mean of 2 liters per minute) was needed in two patients, and one required NIV also during the daytime. Total recovery from SARS-CoV-2 infection was observed in all, despite being in an advanced stage of their disease, with severe respiratory involvement. Prompt medical treatment is recommended for ALS patients with severe disease infected by SARS-CoV-2.

The impact of new bronchial drainage device in a complex form of respiratory disease

Abstract Drainage of secretions in patients with severe lung damage is a challenge. In many cases, due to the significant reduction in muscle mass, difficulties of this nature arise. We present the case of an 82-year-old patient, vaccinated against Severe acute respiratory syndrome coronavirus 2 (SARS COV2), anti-influenza, anti-pneumococcal and anti-haemophilus, former smoker, with no significant exposure to known professional respiratory noxes, with severe comorbidities (cardiac, ophthalmological, rheumatological, neurological, and diabetological) and a congenital pulmonary malformation – right lung hypoplasia (diagnosed in 2008), extensive cystic and varicose bronchiectasis, probably also in a congenital context, with progressive collapse of the right parenchyma and displacement of the mediastinum, complicated with recurrent respiratory infectious episodes with pathogens – Gram-negative germs, anaerobic germs, and repetitive low-amount haemoptysis for 3 years, as well as severe restrictive respiratory dysfunction. Currently, the patient is under bronchodilator treatment, and home oxygen therapy. For about 3 years, regular modern drainage sessions using the studied device have been introduced. Patient adherence was good. The benefits brought by this device on the clinical development of the patient were: efficient drainage of secretions, improvement of the quality of life, and prolongation of survival in a patient with complex pulmonary pathology and multiple comorbidities in development for 13 years. This new therapeutic drainage option has been competing with pre-existing ways (Cough Assist) for several years, demonstrating its multiple benefits in patients with chronic respiratory failure and severe comorbidities.

Hypoventilation syndrome in neuromuscular disorders.

Hypoventilation syndrome in neuromuscular disorders (NMDs) is primarily due to respiratory muscle weakness and results in increased morbidity and mortality. This article highlights current aspects of neuromuscular hypoventilation syndrome, including pathophysiology, clinical symptoms, assessment, respiratory involvement in various NMD, and causal and symptomatic treatments with an emphasis on recent research and advances. New therapeutic agents have been developed within the last years, proving a positive effect on respiratory system. Symptomatic therapies, including mechanical ventilation and cough assistance approaches, are important in NMD and respiratory muscle training may have benefit in strengthening respiratory muscles and should be offered patients with respiratory muscle weakness the same way as physiotherapy. Correct respiratory assessments and their correct interpretation are hallmarks for early diagnosis of hypoventilation syndrome and treatment.

Novel assisted cough system based on simulating cough airflow dynamics.

Cough is a defensive behavior that protects the respiratory system from infection and clears airway secretions. Cough airflow dynamics have been analyzed by a variety of mathematical and experimental tools. In this paper, the cough airflow dynamics of 42 subjects were obtained and analyzed. An identification model based on piecewise Gauss function for cough airflow dynamics is proposed through the dimensionless method, which could achieve over 90% identification accuracy. Meanwhile, an assisted cough system based on pneumatic flow servo system is presented. The vacuum situation and feedback control are used to increase the simulated peak cough flow rate, which are important for airway secretion clearance and to avoid airway collapse, respectively. The simulated cough peak flow could reach 5 L/s without the external assistance such as manual pressing, patient cooperation and other means. Finally, the backstepping control is developed to generate a simulated cough airflow that closely mimics the natural cough airflow of humans. The assisted cough system opens up wide opportunities of practical application in airway secretion clearance for critically ill patients with COVID 2019 and other pulmonary diseases.Graphic abstract

Effectiveness of chest physiotherapy using passive slow expiratory techniques in dogs with airway fluid accumulation: A randomized controlled trial.

BackgroundProlonged slow expiration (PSE) and assisted cough (AC) are airway clearance techniques feasible and well tolerated in dogs.ObjectivesTo evaluate the effectiveness of PSE and AC as chest physiotherapy (CP) techniques in dogs with airway fluid accumulation.AnimalsThirty‐one client‐owned dogs hospitalized in an intensive care unit from October 2014 to May 2018.MethodsProspective randomized controlled trial. Dogs presented with or developing acute dyspnea during hospitalization associated with airway fluid accumulation were assigned to CP group (medical treatment and CP, 15 dogs) or control group (medical treatment alone, 16 dogs). The arterial partial pressure of oxygen (PaO2) to fraction of inspired oxygen (FiO2) ratio (P/F ratio; PaO2/FiO2 × 100) was calculated daily for the 1st 48 hours of hospitalization and using the last arterial blood gas performed before discharge or death. The ratio of days of hospitalization with oxygen/total number of hospitalization days (ratio of oxygen‐free‐days [O2Free]) was calculated.ResultsDuring the 1st 48 hours, the P/F ratio increased significantly in the CP group compared to the control group (+ 35.1 mm Hg/day; 95% confidence interval [CI] = 0.4‐57.5; P = .03). The (median; 1st quartile to 3rd quartile) difference between the P/F ratio at discharge and inclusion was significantly higher in the CP group (178 mm Hg; 123‐241) than in the control group (54 mm Hg; −19 ‐ 109; P = .001). Mean O2Free increased by 46.4% in the CP group compared with control group (95% CI = 16‐59; P = .001). Mortality was 13% (2/15) in the CP group and 44% (7/16) in the control group (P = .07).Conclusions and Clinical ImportanceProlonged slow expiration and AC improved P/F ratio within 48 hours and decreased need for oxygenation in dyspneic dogs with acute airway fluid accumulation.

Airway Clearance Techniques: The Right Choice for the Right Patient.

The management of bronchial secretions is one of the main problems encountered in a wide spectrum of medical conditions ranging from respiratory disorders, neuromuscular disorders and patients undergoing either thoracic or abdominal surgery. The purpose of this review is illustrate to the reader the different ACTs currently available and the related evidence present in literature. Alongside methods with a strong background behind as postural drainage, manual techniques or PEP systems, the current orientation is increasingly aimed at devices that can mobilize and / or remove secretions. Cough Assist, Vacuum Techniques, systems that modulate airflow have more and more scientific evidence. Different principles combination is a new field of investigation that goes toward an increasing of clinical complexity that will facing us.

A atuação da fisioterapia nas repercussões motoras e respiratórias dos pacientes com atrofia muscular espinhal tipo I

OBJECTIVES: To verify in the literature the physiotherapeutic resources that have already been used in the motor and respiratory repercussions of patients with spinal muscular atrophy type I. METHODS: This is a literature review carried out in the PubMed, LILACS, SciELO and PEDro databases, in period from June to August 2019, using the keywords “spinal muscular atrophy type I” OR “Werdnig-Hoffmann syndrome” AND “physiotherapy”, as well as the terms in English. RESULTS: 53 articles were found, but after the inclusion criteria, only 5 were relevant to the research. In the respiratory system, Cough Assist®, nasotracheal aspiration, acceleration of expiratory flow and postural drainage were used, both effective for bronchial hygiene. Pulmonary expansion and noninvasive ventilation improved ventilatory mechanics. In the musculoskeletal system, stretching, joint mobilization, kinesiotherapy, and use of orthoses provided gains in functionality and reduced deformities. CONCLUSIONS: Kinesiotherapy provided motor gains such as cervical control, stretching, mobilization and orthoses, helping to maintain functionality. In respiratory repercussions, the use of Cough Assist®, nasotracheal aspiration, acceleration of expiratory flow and postural drainage were able to reduce hospitalizations for pneumonia. The pulmonary expansion and noninvasive ventilation maneuvers reversed microatelectasis, improved hematosis and contributed to increased life expectancy.

Cardiopulmonary phenotypic variability and discordance in Duchenne muscular dystrophy: Implications for new therapies

Neuromuscular respiratory medicine has traditionally focused on assisted lung ventilation and mucus clearance. These therapies have prolonged survival for patients with Duchenne muscular dystrophy (DMD). However, the field is rapidly evolving in a new direction: it is being revolutionized by molecular and genetic therapies. A good correlation between a patient's dystrophin mutation and his cardiopulmonary phenotype would allow accurate prediction of patient prognosis and would facilitate the design of studies that assess new DMD therapies. Instead, patient prognosis and the design of valid therapeutic studies are complicated by cardiopulmonary phenotypic discordance and variability, by which a notable proportion of DMD patients have unexpectedly good or poor cardiopulmonary function. The likely cause of phenotypic variability and discordance is genetic modifiers. Once the modifiers that affect cardiopulmonary function are better understood, it should be possible to create a personalized genetic profile that accurately predicts the prognosis of each individual DMD patient. This would allow investigators to assess the effect of new therapies in the context of each patient's particular cardiopulmonary natural history. Amplification of beneficial cardiopulmonary genetic modifiers and blocking of detrimental modifiers is a promising strategy for creating new DMD therapies. When patients with chronic respiratory failure are treated with assisted ventilation, cardiac function determines their survival. Therefore, prioritizing new cardiac therapies is most likely to prolong patient survival. By focusing on these topics we aim to move neuromuscular respiratory medicine beyond assisted ventilation and coughing and into the age of translational medicine.

A Review of Different Stimulation Methods for Functional Reconstruction and Comparison of Respiratory Function after Cervical Spinal Cord Injury.

Background Spinal cord injury (SCI) is a common severe trauma in clinic, hundreds of thousands of people suffer from which every year in the world. In terms of injury location, cervical spinal cord injury (CSCI) has the greatest impact. After cervical spinal cord injury, the lack of innervated muscles is not enough to provide ventilation and other activities to complete the respiratory function. In addition to the decline of respiratory capacity, respiratory complications also have a serious impact on the life of patients. The most commonly used assisted breathing and cough equipment is the ventilator, but in recent years, the functional electrical stimulation method is being used gradually and widely. Methods About hundred related academic papers are cited for data analysis. They all have the following characteristics: (1) basic conditions of patients were reported, (2) patients had received nerve or muscle stimulation and the basic parameters, and (3) the results were evaluated based on some indicators. Results The papers mentioned above are classified as four kinds of stimulation methods: muscle electric/magnetic stimulation, spinal dural electric stimulation, intraspinal microstimulation, and infrared light stimulation. This paper describes the stimulation principle and application experiment. Finally, this paper will compare the indexes and effects of typical stimulation methods, as well as the two auxiliary methods: training and operation. Conclusions Although there is limited evidence for the treatment of respiratory failure by nerve or muscle stimulation after cervical spinal cord injury, the two techniques seem to be safe and effective. At the same time, light stimulation is gradually applied to clinical medicine with its strong advantages and becomes the development trend of nerve stimulation in the future.

Correlation of Bone Mineral Density with Pulmonary Function in Advanced Duchenne Muscular Dystrophy.

A relationship between bone mineral density (BMD) and physical function has been revealed in the general population and various diseases. However, there is a lack of research investigating the correlation between BMD and respiratory function, one of few measurable physical parameters in patients with advanced Duchenne muscular dystrophy (DMD). To determine whether pulmonary function parameters, including respiratory muscle strength, are related to BMD. Retrospective observational study. A tertiary university hospital. DMD patients who were over 20 years of age, nonambulatory, and supported by mechanical ventilators. The patients' age, weight, and pulmonary function as well as the BMD of the first and the fourth lumbar vertebra were assessed. Pulmonary function includes forced vital capacity (FVC), unassisted and assisted peak cough flow (UPCF and APCF), maximal expiratory pressure (MEP), and maximal inspiratory pressure (MIP). A bivariate correlation for BMD and other pulmonary parameters was calculated, and hierarchical regression analysis was used to determine predictors of spine Z-score. It was observed that the decrease in the spine BMD was not significantly correlated with age. However, the body mass index (BMI) and all parameters of pulmonary function were correlated with BMD. Partial correlation analysis adjusted by BMI showed that UPCF and APCF were powerful predictors of spine BMD. The BMD of the lumbar spine correlated with BMI and PCF in patients with DMD at an advanced stage.