Assisted Cough and Pulmonary Compliance in Patients with Duchenne Muscular Dystrophy

The aim of this study was to investigate the factors affecting cough ability, and to compare the assisted cough methods in patients with Duchenne muscular dystrophy (DMD). A total seventy-one male patients with DMD were included in the study. The vital capacity (VC) and maximum insufflation capacity (MIC) were measured. The unassisted peak cough flow (UPCF) and three different techniques of assisted peak cough flow were evaluated. UPCF measurements were possible for all 71 subjects. But when performing the three different assisted cough techniques, peak cough flows (PCFs) could be obtained from only 51 subjects. The mean value of MICs (1801 ± 780 cc) was higher than that of VCs (1502 ± 765 cc) (p < 0.01). All three assisted cough methods showed a significantly higher value than the unassisted method (F=80.92, p < 0.01). The manual assisted PCF under MIC (MPCFmic) significantly exceeded those produced by manual assisted PCF (MPCF) or PCF under MIC (PCFmic). The positive correlation between the MIC, VC difference (MIC-VC), and the difference between PCFmic and UPCF (PCFmic-UPCF) was seen (r=0.572, p < 0.01). The preservation of pulmonary compliance is important for the development of an effective cough as well as assisting the compression and expulsive phases. Thus, the clinical importance of the inspiratory phase and pulmonary compliance in assisting a cough should be emphasized

Artificial External Glottic Device for Passive Lung Insufflation

PURPOSE: For patients with neuromuscular disease, air stacking, which inflates the lungs to deep volumes, is important for many reasons. However, neuromuscular patients with severe glottic dysfunction or indwelling tracheostomy tubes cannot air stack effectively. For these patients, we developed a device that permits deep lung insufflations substituting for glottic function. MATERIALS AND METHODS: Thirty- seven patients with bulbar-innervated muscle weakness and/or tracheostomies were recruited. Twenty-three had amyotrophic lateral sclerosis, and 14 were tetraplegic patients due to cervical spinal cord injury. An artificial external glottic device (AEGD) was used to permit passive deep lung insufflation. In order to confirm the utility of AEGD, vital capacity, maximum insufflation capacity (MIC), and lung insufflation capacity (LIC) with AEGD (LICA) were measured. RESULTS: For 30 patients, MICs were initially zero. However, with the use of the AEGD, LICA was measurable for all patients. The mean LICA was 1,622.7±526.8 mL. Although MIC was measurable for the remaining 7 patients without utilizing the AEGD, it was significantly less than LICA, which was 1,084.3±259.9 mL and 1,862.9±248 mL, respectively (p<0.05). CONCLUSION: The AEGD permits lung insufflation by providing deeper lung volumes than possible by air stacking.ope

Respiratory Muscle Strength and Cough Capacity in Patients with Duchenne Muscular Dystrophy

The function of inspiratory muscles is crucial for effective cough as well as expiratory muscles in patients with Duchenne muscular dystrophy (DMD). However, there is no report on the correlation between cough and inspiratory muscle strength. To investigate the relationships of voluntary cough capacity, assisted cough techniques, and inspiratory muscle strength as well as expiratory muscle strength in patients with DMD (n = 32). The vital capacity (VC), maximum insufflation capacity (MIC), maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) were measured. Unassisted peak cough flow (UPCF) and three different techniques of assisted PCF were evaluated. The mean value of MICs (1918 ± 586 mL) was higher than that of VCs (1474 ± 632 mL) (p < 0.001). All three assisted cough methods showed significantly higher value than unassisted method (212 ± 52 L/min) (F = 66.13, p < 0.001). Combined assisted cough technique (both manual and volume assisted PCF; 286 ± 41 L/min) significantly exceeded manual assisted PCF (MPCF; 246 ± 49 L/min) and volume assisted PCF (VPCF; 252 ± 45 L/min) (F = 66.13, p < 0.001). MIP (34 ± 13 cmH2O) correlated significantly with both UPCF and all three assisted PCFs as well as MEP (27 ± 10 cmH2O) (p < 0.001). Both MEP and MIP, which are the markers of respiratory muscle weakness, should be taken into account in the study of cough effectiveness

Pulmonary Rehabilitation in Patients with Neuromuscular Disease

In neuromuscular disease (NMD) patients with progressive muscle weakness, respiratory muscles are also affected and hypercapnia can increase gradually as the disease progresses. The fundamental respiratory problems NMD patients experience are decreased alveolar ventilation and coughing ability. For these reasons, it is necessary to precisely evaluate pulmonary function to provide the proper inspiratory and expiratory muscle aids in order to maintain adequate respiratory function. As inspiratory muscle weakening progresses, NMD patients experience hypoventilation. At this point, respiratory support by mechanical ventilator should be initiated to relieve respiratory distress symptoms. Patients with adequate bulbar muscle strength and cognitive function who use a non-invasive ventilation aid, via a mouthpiece or a nasal mask, may have their hypercapnia and associated symptoms resolved. For a proper cough assist, it is necessary to provide additional insufflation to patients with inspiratory muscle weakness before using abdominal thrust. Another effective method for managing airway secretions is a device that performs mechanical insufflation-exsufflation. In conclusion, application of non-invasive respiratory aids, taking into consideration characterization of respiratory pathophysiology, have made it possible to maintain a better quality of life in addition to prolonging the life span of patients with NMD

How Respiratory Muscle Strength Correlates with Cough Capacity in Patients with Respiratory Muscle Weakness

PURPOSE: The purpose of this study is to investigate how respiratory muscle strength correlates to cough capacity in patients with respiratory muscle weakness. MATERIALS AND METHODS: Forty-five patients with amyotrophic lateral sclerosis (ALS), 43 with cervical spinal cord injury (SCI), and 42 with Duchenne muscular dystrophy (DMD) were recruited. Pulmonary function tests including forced vital capacity (FVC) and respiratory muscle strength (maximal expiratory pressure, MEP; maximal inspiratory pressure, MIP) were performed. The correlation between respiratory muscle strength and cough capacity was analyzed. RESULTS: In the SCI group, FVC in a supine position (2,597 +/- 648 mL) was significantly higher than FVC in a sitting position (2,304 +/- 564 mL, p < 0.01). Conversely, in the ALS group, FVC sitting (1,370 +/- 604 mL) was significantly higher than in supine (1,168 +/- 599 mL, p < 0.01). In the DMD group, there was no statistically significant difference between FVC while sitting (1,342 +/- 506 mL) and FVC while supine (1,304 +/- 500 mL). In addition, the MEP and MIP of all three groups showed a significant correlation with peak cough flow (PCF) (p < 0.01, Pearson's correlation analysis). In the SCI group, MIP was more closely correlated with PCF, while in the ALS and DMD groups, MEP was more closely correlated with PCF (p < 0.01, multiple regression analysis). CONCLUSION: To generate cough flow, inspiratory muscle strength is significantly more important for SCI patients, while expiratory muscle function is significantly more important for ALS and DMD patients.ope

Azithromycin for treatment of bronchiolitis obliterans syndrome in adult lung transplant recipients

This is a protocol for a Cochrane Review (Intervention). The objectives are as follows: This review aims to look at the benefits and harms of azithromycin for the treatment of BOS in adult lung transplant recipients

Abdominal functional electrical stimulation to improve respiratory function after spinal cord injury: a systematic review and meta-analysis

Objectives: Abdominal functional electrical stimulation (abdominal FES) is the application of a train of electrical pulses to the abdominal muscles, causing them to contract. Abdominal FES has been used as a neuroprosthesis to acutely augment respiratory function and as a rehabilitation tool to achieve a chronic increase in respiratory function after abdominal FES training, primarily focusing on patients with spinal cord injury (SCI). This study aimed to review the evidence surrounding the use of abdominal FES to improve respiratory function in both an acute and chronic manner after SCI. Settings: A systematic search was performed on PubMed, with studies included if they applied abdominal FES to improve respiratory function in patients with SCI. Methods: Fourteen studies met the inclusion criteria (10 acute and 4 chronic). Low participant numbers and heterogeneity across studies reduced the power of the meta-analysis. Despite this, abdominal FES was found to cause a significant acute improvement in cough peak flow, whereas forced exhaled volume in 1 s approached significance. A significant chronic increase in unassisted vital capacity, forced vital capacity and peak expiratory flow was found after abdominal FES training compared with baseline. Conclusions: This systematic review suggests that abdominal FES is an effective technique for improving respiratory function in both an acute and chronic manner after SCI. However, further randomised controlled trials, with larger participant numbers and standardised protocols, are needed to fully establish the clinical efficacy of this technique

Comparison of the Ratio of Upper to Lower Chest Wall in Children with Spastic Quadriplegic Cerebral Palsy and Normally Developed Children

The upper chest wall does not grow properly in children with spinal muscular atrophy (SMA) with paradoxical breathing. This suggests that long-term inability to take a deep breath in developing children may result in underdevelopment of the upper chest wall. In addition, a rapid and paradoxical breathing pattern is frequently observed in children with severe cerebral palsy (CP), which often corresponds to the underdevelopment of the upper chest wall. The present study is designed to evaluate the ratio of the upper to lower chest wall in children with severe spastic quadriplegic CP, compared with normal children. We compared normal children with children that had spastic quadriplegic CP who did not have kyphosis or scoliosis. Test subjects were matched in terms of age, height, and weight. The diameters of upper chest (Dapex) and of lower chest (Dbase) were measured on the anteroposterior (AP) view of a chest X-ray and the Dapex to Dbase ratio was calculated. In selected cases the forced vital capacity (FVC) was measured using a Wright Respirometer. The Dapex to Dbase ratio was significantly lower in the CP group than in the control group (p<0.001). The ratio increased linearly with age (p<0.001) in both CP (R = 0.372) and control groups (R = 0.477). The FVC/preFVC showed significant correlation with the Dapex to Dbase ratio (R = 0.542, p<0.01). The results of this study suggest a deviation of optimal chest wall structure in children with spastic quadriplegic CP