AN OVERVIEW OF RESPIRATORY MUSCLE FUNCTION

The Effect of Threshold Loading Training and an Innovative Respiratory Training Devices with Lower Torso Sports Training in Asthma Patients: A Randomized Trial

This study investigated the influence of two different devices with lower torso sports training in patients with asthma. Patients with asthma (n = 300) aged 55-60 years with FEV1/FVC ratio < 65%, who were repeatedly admitted to a pulmonary rehabilitation centre, participated. Patients were evaluated and randomized into two groups (experimental group 1; EXP-1, n = 150, who applied a conventional threshold loading device, and experimental group 2; EXP-2, n = 150, who used an innovative respiratory training device). Patients were included only if they met the global criteria for asthma. The experimental intervention period lasted 10 weeks with 3 weekly training sessions lasting 30-40 min. The maximal inspiratory pressure (PI, max), pulmonary function test, baseline dyspnoea index (BDI), oxygen saturation, and 6 min walking test (6MWT) performance were all measured at baseline and postintervention. Also, an assessment of the 1 min repeated exercise performance (leg extension and leg press) was performed. Moreover, St. George Respiratory Questionnaire was used to quantify the quality of life (SGRQ). Statistical analysis displayed significant favourable effects on 6MWT, leg press, and FRV1, for patients using both devices (EXP-1 and EXP-2, respectively) with lower torso athletic training. The other variables, weight SPO2 and SGRO, also showed no significant change in neither EXP-1 nor EXP-2. Thus, the new respiratory training device (EXP-2) appeared to be as effective as the conventional threshold loading device (EXP-1). In conclusion, our findings demonstrated beneficial effects of combining respiratory training with athletic training in asthma patients. Additionally, the validity of a unique respiratory training device for asthma patients was confirmed.

Evaluation of primary and accessory respiratory muscles and their influence on exercise capacity and dyspnea in pulmonary arterial hypertension

BACKGROUND

Skeletal and respiratory muscle disfunction has been described in pulmonary arterial hypertension (PAH), however, involvement of accessory respiratory muscles and their association with symptomatology in PAH is unclear.

OBJECTIVES

To assess the primary and accessory respiratory muscles and their influence on exercise tolerance and dyspnea.

METHODS

27 patients and 27 healthy controls were included. Serratus anterior (SA), pectoralis muscles (PM) and sternocleidomastoid (SCM) muscle strength were evaluated as accessory respiratory muscles, maximal inspiratory (MIP) and expiratory pressures (MEP) as primary respiratory muscles, and quadriceps as peripheral muscle. Exercise capacity was evaluated with 6-min walk test (6MWT), dyspnea with modified Medical Council Research (MMRC) and London Chest Activity of Daily Living (LCADL) scales.

RESULTS

All evaluated muscles, except SCM, and 6MWT were decreased in patient group (p < 0.01). SA was the most affected muscle among primary and accessory respiratory muscles (Cohen's-d = 1.35). All evaluated muscles significantly correlated to 6MWT (r = 0.428-0.525). A multivariate model including SA, SCM and MIP was the best model for predicting 6MWT (R = 0.606; R² = 0.368; p = 0.013) and SA strength had the most impact on the 6MWT (B = 1.242; β = 0.340). None of the models including respiratory muscles were able to predict dyspnea, however PM and SA strength correlated to LCADL _total (r = -0.493) and MMRC (r = -0.523), respectively.

CONCLUSION

SCM may be excessively used in PAH since it retains its strength. Considering the relationship of accessory respiratory muscles with exercise tolerance and dyspnea, monitoring the strength of these muscles in the clinical practice may help providing better management for PAH.

Clinical Characteristics and Outcome of MDR/XDR Bacterial Infections in a Neuromuscular Semi-Intensive/Sub-Intensive Care Unit

(1) Background: The aim of this study was to assess the clinical and microbiological characteristics of multidrug-resistant infections in a neuromuscular semi-intensive/sub-intensive care unit; (2) Methods: Retrospective analysis on data from 18 patients with NMD with proven MDRO/XDRO colonisation/infection from August 2021 to March 2022 was carried out; (3) Results: Ten patients were males (55.6%), with a median age of 54 years, and there were fourteen patients (77.8%) with amyotrophic lateral sclerosis. All patients had at least one invasive device. Ten (55.6%) patients developed MDRO/XDRO infection (with a median time of 24 days) while six (33.3%) were colonised. The Charlson comorbidity index was >2 in both groups but higher in the infected compared with the colonised (4.5 vs. 3). Infected patients were mostly females (seven patients) with a median age of 62 years. The most common pathogens were Acinetobacter baumannii and Pseudomonas aeruginosa, infecting four (28.6%) patients each. Of eighteen infectious episodes, nine were pneumonia (hospital-acquired in seven cases). Colistin was the most commonly active antibiotic while carbapenems were largely inactive. Eradication of infection occurred in seven infectious episodes (38.9%). None of those with infection died; (4) Conclusions: MDRO/XDRO infections are common in patients with neuromuscular diseases, with carbapenem-resistant non-fermenting Gram-negative bacilli prevailing. These infections were numerically associated with the female sex, greater age, and comorbidities. Both eradication and infection-related mortality appeared low. We highlight the importance of infection prevention in this vulnerable population.

Respiratory Inductance Plethysmography to Assess Fatigability during Repetitive Work

Cumulative fatigue during repetitive work is associated with occupational risk and productivity reduction. Usually, subjective measures or muscle activity are used for a cumulative evaluation; however, Industry 4.0 wearables allow overcoming the challenges observed in those methods. Thus, the aim of this study is to analyze alterations in respiratory inductance plethysmography (RIP) to measure the asynchrony between thorax and abdomen walls during repetitive work and its relationship with local fatigue. A total of 22 healthy participants (age: 27.0 ± 8.3 yrs; height: 1.72 ± 0.09 m; mass: 63.4 ± 12.9 kg) were recruited to perform a task that includes grabbing, moving, and placing a box in an upper and lower shelf. This task was repeated for 10 min in three trials with a fatigue protocol between them. Significant main effects were found from Baseline trial to the Fatigue trials (p < 0.001) for both RIP correlation and phase synchrony. Similar results were found for the activation amplitude of agonist muscle (p < 0.001), and to the muscle acting mainly as a joint stabilizer (p < 0.001). The latter showed a significant effect in predicting both RIP correlation and phase synchronization. Both RIP correlation and phase synchronization can be used for an overall fatigue assessment during repetitive work.

Sarcopenia is not associated with inspiratory muscle strength but with expiratory muscle strength among older adults requiring long-term care/support

BACKGROUND

Recently, the concept of respiratory sarcopenia has been advocated, but evidence is lacking regarding which respiratory parameters are appropriate indicators. Therefore, we investigated the association between sarcopenia, respiratory function, and respiratory muscle strength to identify the most appropriate parameters for respiratory sarcopenia.

METHODS

We included 124 older adults (67 men, 57 women; average age 77.2 ± 8.3 years) requiring long-term care/support who underwent Day Care for rehabilitation. Handgrip strength, usual gait speed, and skeletal muscle mass were measured using bioelectrical impedance analysis. Participants were then diagnosed with sarcopenia using the algorithm of the Asian Working Group for Sarcopenia 2019. Parameters of respiratory function (forced vital capacity, forced expiratory volume in one second [FEV1.0], FEV1.0%, and peak expiratory flow rate) and respiratory muscle strength (maximal expiratory pressure [MEP] and maximal inspiratory pressure) were also measured according to American Thoracic Society guidelines. Respiratory parameters significantly related to sarcopenia were identified using binomial logistic regression and receiver operating characteristic analyses.

RESULTS

Seventy-seven participants were classified as having sarcopenia. Binomial logistic regression analysis showed that MEP was the only respiratory parameter significantly associated with sarcopenia. The cut-off MEP value for predicting sarcopenia was 47.0 cmH₂0 for men and 40.9 cmH₂0 for women.

CONCLUSIONS

The most appropriate parameter for assessing respiratory sarcopenia may be MEP, which is an indicator of expiratory muscle strength, rather than FVC, MIP, or PEFR, as suggested in previous studies. Measuring MEP is simpler than measuring respiratory function parameters. Moreover, it is expected to have clinical applications such as respiratory sarcopenia screening.

Respiratory muscle training in children and adults with neuromuscular disease

BACKGROUND

Neuromuscular diseases (NMDs) are a heterogeneous group of diseases affecting the anterior horn cell of spinal cord, neuromuscular junction, peripheral nerves and muscles. NMDs cause physical disability usually due to progressive loss of strength in limb muscles, and some NMDs also cause respiratory muscle weakness. Respiratory muscle training (RMT) might be expected to improve respiratory muscle weakness; however, the effects of RMT are still uncertain. This systematic review will synthesize the available trial evidence on the effectiveness and safety of RMT in people with NMD, to inform clinical practice.

OBJECTIVES

To assess the effects of respiratory muscle training (RMT) for neuromuscular disease (NMD) in adults and children, in comparison to sham training, no training, standard treatment, breathing exercises, or other intensities or types of RMT.

SEARCH METHODS

On 19 November 2018, we searched the Cochrane Neuromuscular Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and Embase. On 23 December 2018, we searched the US National Institutes for Health Clinical Trials Registry (ClinicalTrials.gov), the World Health Organization International Clinical Trials Registry Platform, and reference lists of the included studies.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) and quasi-RCTs, including cross-over trials, of RMT in adults and children with a diagnosis of NMD of any degree of severity, who were living in the community, and who did not need mechanical ventilation. We compared trials of RMT (inspiratory muscle training (IMT) or expiratory muscle training (EMT), or both), with sham training, no training, standard treatment, different intensities of RMT, different types of RMT, or breathing exercises.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methodological procedures.

MAIN RESULTS

We included 11 studies involving 250 randomized participants with NMDs: three trials (N = 88) in people with amyotrophic lateral sclerosis (ALS; motor neuron disease), six trials (N = 112) in Duchenne muscular dystrophy (DMD), one trial (N = 23) in people with Becker muscular dystrophy (BMD) or limb-girdle muscular dystrophy, and one trial (N = 27) in people with myasthenia gravis.Nine of the trials were at high risk of bias in at least one domain and many reported insufficient information for accurate assessment of the risk of bias. Populations, interventions, control interventions, and outcome measures were often different, which largely ruled out meta-analysis. All included studies assessed lung capacity, our primary outcome, but four did not provide data for analysis (1 in people with ALS and three cross-over studies in DMD). None provided long-term data (over a year) and only one trial, in ALS, provided information on adverse events. Unscheduled hospitalisations for chest infection or acute exacerbation of chronic respiratory failure were not reported and physical function and quality of life were reported in one (ALS) trial.Amyotrophic lateral sclerosis (ALS)Three trials compared RMT versus sham training in ALS. Short-term (8 weeks) effects of RMT on lung capacity in ALS showed no clear difference in the change of the per cent predicted forced vital capacity (FVC%) between EMT and sham EMT groups (mean difference (MD) 0.70, 95% confidence interval (CI) -8.48 to 9.88; N = 46; low-certainty evidence). The mean difference (MD) in FVC% after four months' treatment was 10.86% in favour of IMT (95% CI -4.25 to 25.97; 1 trial, N = 24; low-certainty evidence), which is larger than the minimal clinically important difference (MCID, as estimated in people with idiopathic pulmonary fibrosis). There was no clear difference between IMT and sham IMT groups, measured on the Amyotrophic Lateral Sclerosis Functional Rating Scale (ALFRS; range of possible scores 0 = best to 40 = worst) (MD 0.85, 95% CI -2.16 to 3.85; 1 trial, N = 24; low-certainty evidence) or quality of life, measured on the EuroQol-5D (0 = worst to 100 = best) (MD 0.77, 95% CI -17.09 to 18.62; 1 trial, N = 24; low-certainty evidence) over the medium term (4 months). One trial report stated that the IMT protocol had no adverse effect (very low-certainty evidence).Duchenne muscular dystrophy (DMD)Two DMD trials compared RMT versus sham training in young males with DMD. In one study, the mean post-intervention (6-week) total lung capacity (TLC) favoured RMT (MD 0.45 L, 95% CI -0.24 to 1.14; 1 trial, N = 16; low-certainty evidence). In the other trial there was no clear difference in post-intervention (18 days) FVC between RMT and sham RMT (MD 0.16 L, 95% CI -0.31 to 0.63; 1 trial, N = 20; low-certainty evidence). One RCT and three cross-over trials compared a form of RMT with no training in males with DMD; the cross-over trials did not provide suitable data. Post-intervention (6-month) values showed no clear difference between the RMT and no training groups in per cent predicted vital capacity (VC%) (MD 3.50, 95% CI -14.35 to 21.35; 1 trial, N = 30; low-certainty evidence).Becker or limb-girdle muscular dystrophyOne RCT (N = 21) compared 12 weeks of IMT with breathing exercises in people with Becker or limb-girdle muscular dystrophy. The evidence was of very low certainty and conclusions could not be drawn.Myasthenia gravisIn myasthenia gravis, there may be no clear difference between RMT and breathing exercises on measures of lung capacity, in the short term (TLC MD -0.20 L, 95% CI -1.07 to 0.67; 1 trial, N = 27; low-certainty evidence). Effects of RMT on quality of life are uncertain (1 trial; N = 27).Some trials reported effects of RMT on inspiratory and/or expiratory muscle strength; this evidence was also of low or very low certainty.

AUTHORS' CONCLUSIONS

RMT may improve lung capacity and respiratory muscle strength in some NMDs. In ALS there may not be any clinically meaningful effect of RMT on physical functioning or quality of life and it is uncertain whether it causes adverse effects. Due to clinical heterogeneity between the trials and the small number of participants included in the analysis, together with the risk of bias, these results must be interpreted very cautiously.

Maximum inspiratory pressure as a clinically meaningful trial endpoint for neuromuscular diseases: a comprehensive review of the literature

Respiratory muscle strength is a proven predictor of long-term outcome of neuromuscular disease (NMD), including amyotrophic lateral sclerosis, Duchenne muscular dystrophy, and spinal muscular atrophy. Maximal inspiratory pressure (MIP), a sensitive measure of respiratory muscle strength, one of several useful tests of respiratory muscle strength, is gaining interest as a therapeutic clinical trial endpoint for NMD. In this comprehensive review we investigate the use of MIP as a measure of respiratory muscle strength in clinical trials of therapeutics targeting respiratory muscle, examine the correlation of MIP with survival, quality of life, and other measures of pulmonary function, and outline the role of MIP as a clinically significantly meaningful outcome measure. Our analysis supports the utility of MIP for the early evaluation of respiratory muscle strength, especially of the diaphragm, in patients with NMD and as a surrogate endpoint in clinical trials of therapies for NMD.

Neurologic Causes of Acute Respiratory Dysfunction

Many neurologic diseases can cause acute respiratory decompensation, therefore a familiarity with these diseases is critical for any clinician managing patients with respiratory dysfunction. In this article, we review the anatomy of the respiratory system, focusing on the neurologic control of respiration. We discuss general mechanisms by which diseases of the peripheral and central nervous systems can cause acute respiratory dysfunction, and review the neurologic diseases which can adversely affect respiration. Lastly, we discuss the diagnosis and general management of acute respiratory impairment due to neurologic disease.

Current issues in the respiratory care of patients with amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis is a progressive neuromuscular disease, resulting in respiratory muscle weakness, reduced pulmonary volumes, ineffective cough, secretion retention, and respiratory failure. Measures as vital capacity, maximal inspiratory and expiratory pressures, sniff nasal inspiratory pressure, cough peak flow and pulse oximetry are recommended to monitor the respiratory function. The patients should be followed up by a multidisciplinary team, focused in improving the quality of life and deal with the respiratory symptoms. The respiratory care approach includes airway clearance techniques, mechanically assisted cough and noninvasive mechanical ventilation. Vaccination and respiratory pharmacological support are also recommended. To date, there is no enough evidence supporting the inspiratory muscle training and diaphragmatic pacing.

Respiratory muscle training for respiratory deficits in neurodegenerative disorders: a systematic review

BACKGROUND

Studies of the impact of respiratory muscle training (RMT) on central neurodegenerative pathologies have been aimed at improving pulmonary function. However, there is no certainty about the effectiveness of RMT in patients affected by these groups of disorders. The purpose of this review was to assess the evidence regarding the efficacy of inspiratory muscle training (IMT) and expiratory muscle training (EMT) on respiratory function in patients with neurodegenerative disorders of the CNS.

METHODS

A comprehensive search from 1990 to September 2012 on MEDLINE, Physiotherapy Evidence Database (PEDro), PubMed, Cochrane Library, and Cumulative Index to Nursing and Allied Health Literature (CINAHL) databases was made. Studies reporting on IMT and EMT in patients with neurodegenerative diseases were included. The selected studies were abstracted using a standardized data collection instrument and were assessed by a quality checklist created and adapted from CONSORT (Consolidated Standards for Reporting Trials) and TREND (Transparent Reporting of Evaluation with Nonrandomized Designs).

RESULTS

Twenty-four studies were identified by the search strategy. Only 19 studies met the criteria for full review. Ten studies met all the inclusion criteria and were included in the final analysis. Of the 16 parameters present in the quality assessment checklist, only six were achieved for the studies analyzed.

CONCLUSIONS

There is some evidence that RMT improves a number of respiratory function parameters in patients with Parkinson disease and multiple sclerosis; however, the number of studies and their quality are not sufficient to conclude whether IMT or EMT is effective in improving respiratory function in patients with neurodegenerative disorders of the CNS.

Pathophysiology of muscle dysfunction in COPD

Muscle dysfunction often occurs in patients with chronic obstructive pulmonary disease (COPD) and may involve both respiratory and locomotor (peripheral) muscles. The loss of strength and/or endurance in the former can lead to ventilatory insufficiency, whereas in the latter it limits exercise capacity and activities of daily life. Muscle dysfunction is the consequence of complex interactions between local and systemic factors, frequently coexisting in COPD patients. Pulmonary hyperinflation along with the increase in work of breathing that occur in COPD appear as the main contributing factors to respiratory muscle dysfunction. By contrast, deconditioning seems to play a key role in peripheral muscle dysfunction. However, additional systemic factors, including tobacco smoking, systemic inflammation, exercise, exacerbations, nutritional and gas exchange abnormalities, anabolic insufficiency, comorbidities and drugs, can also influence the function of both respiratory and peripheral muscles, by inducing modifications in their local microenvironment. Under all these circumstances, protein metabolism imbalance, oxidative stress, inflammatory events, as well as muscle injury may occur, determining the final structure and modulating the function of different muscle groups. Respiratory muscles show signs of injury as well as an increase in several elements involved in aerobic metabolism (proportion of type I fibers, capillary density, and aerobic enzyme activity) whereas limb muscles exhibit a loss of the same elements, injury, and a reduction in fiber size. In the present review we examine the current state of the art of the pathophysiology of muscle dysfunction in COPD.

Effect of training frequency on maximum expiratory pressure

PURPOSE

To determine the effects of expiratory muscle strength training (EMST) frequency on maximum expiratory pressure (MEP).

METHOD

We assigned 12 healthy participants to 2 groups of training frequency (3 days per week and 5 days per week). They completed a 4-week training program on an EMST trainer (Aspire Products, LLC). MEP was the primary outcome measure used to determine the effect of training frequency.

RESULTS

Participants who trained 3 days per week produced equivalent amounts of improvement in MEP compared with participants who trained 5 days per week. An overall improvement in MEP over the 4-week training period indicated a 33% increase when the data was collapsed across the 2 training groups.

CONCLUSION

The effects occurring with respiratory muscle strength training in healthy young adults are likely to be different from those occurring in patient populations. Therefore, the results of the present study suggest exploring the variable of training frequency in patient populations. Such knowledge will be informative for designing clinical protocols that are effective and may result in improved treatment compliance for those suffering from expiratory muscle weakness.

Respiratory diseases and muscle dysfunction

Many respiratory diseases lead to impaired function of skeletal muscles, influencing quality of life and patient survival. Dysfunction of both respiratory and limb muscles in chronic obstructive pulmonary disease has been studied in depth, and seems to be caused by the complex interaction of general (inflammation, impaired gas exchange, malnutrition, comorbidity, drugs) and local factors (changes in respiratory mechanics and muscle activity, and molecular events). Some of these factors are also present in cystic fibrosis and asthma. In obstructive sleep apnea syndrome, repeated exposure to hypoxia and the absence of reparative rest are believed to be the main causes of muscle dysfunction. Deconditioning appears to be crucial for the functional impairment observed in scoliosis. Finally, cachexia seems to be the main mechanism of muscle dysfunction in advanced lung cancer. A multidimensional therapeutic approach is recommended, including pulmonary rehabilitation, an adequate level of physical activity, ventilatory support and nutritional interventions.

Diaphragmatic adaptation following intra-abdominal weight changing

BACKGROUND

The diaphragm, the major respiratory muscle, contains three types of muscular fibers in dynamic balance between them. The fiber ratios vary in time in function of conditions, such as aging, hypoproteinemia, exercise, and chronic respiratory load. The diaphragmatic adaptation following abdominal conditions remains an unexplored field. This experimental study aims to identify the changes of the diaphragm due to chronic abdominal weight load. This may find application in conditions such as pregnancy, ascites, visceromegaly, large masses, and morbid obesity.

METHODS

Thirty rabbits were divided into control (A) and study (B) groups. Group B was loaded with weight for 2 months. The left costal hemidiaphragm were stained with H&E and ATPase (fiber typing), while the right underwent biochemical analysis (prooxidative-antioxidative balance, lipid peroxidation, superoxide dismutase, glutathione reductase and peroxidase activities, total glutathione, and protein carbonylation).

RESULTS

In H&E, all fibers were within normal range. ATPase analysis demonstrated reduction of type I (p = 0.019) and an increase of the type ΙΙ(Α) fibers ratio (p < 0.001) in group B, while the type ΙΙ(Β/X) fibers ratio remained stable. The above suggest remodeling of type I fibers into type II(A). Concerning biochemical analysis, difference was observed in glutathione peroxidase activity (p < 0.001).

CONCLUSIONS

Chronically loaded abdomen leads to morphological adaptations of the costal diaphragm, but with minor oxidative stress. These diaphragmatic morphological changes are equivalent to heart failure or severe COPD, showing that this remodeling makes the muscle more efficient towards work load, but more vulnerable to fatigue.

Management of chest wall reconstruction after resection for cancer: a retrospective study of 22 consecutive patients

AIM

In this study, we report our experience on immediate reconstruction after resection of primary or metastatic chest wall tumors, to restore protective function and elasticity of chest or sternum.

METHODS

Between 2005 and 2009, 22 patients underwent reconstruction using a free or pedicled flap combined, or not, to alloplastic materials (Goretex®) in order to cover full-thickness defects of the chest wall after cancer surgery. Reconstruction was immediate in all cases.

RESULTS

Mean follow-up was 27 months. Of these, 18 patients were alive at the end of the study (81.5%). Eighteen patients had malignant tumors (82%); within these patients, 12 were alive without recurrence at the end of the study (67%). The average size of the chest wall defect was 255 cm². Goretex® Mesh was used in 8 patients. All patients benefited from reconstruction with a flap: pedicled or free latissimus dorsi flap (n = 15), pedicled great omentum (n=3), deep inferior epigastric perforator free flap (n = 3), and parascapular pedicled flap (n=1).

CONCLUSION

In this series, we were able to achieve long-term palliation and even cure in some patients by resecting full-thickness chest wall in local primary or recurrence of breast cancer without increasing morbidity. The same process was used successfully in association with adjuvant treatment in other tumors like skin sarcoma. We have followed a surgical algorithm according to the tumor localization and etiology.

Força muscular respiratória de mulheres obesas mórbidas e eutróficas

A obesidade mórbida é uma condição clínica que afeta a capacidade funcional, sendo a musculatura respiratória igualmente comprometida. Objetivou-se avaliar a força muscular inspiratória e expiratória de mulheres obesas mórbidas (MO) e eutróficas (ME). Estudo transversal com amostra composta por 21 mulheres (14 MO e 7 ME), pareadas pela idade e altura. A avaliação da força muscular inspiratória e expiratória foi realizada por meio da verificação das pressões inspiratória e expiratória por manovacuometria. Quando comparadas as pressões respiratórias estáticas máximas obtidas com os valores preditos para ME e MO, constata-se que as do primeiro grupo apresentam valores de P Imáx=119,14±1,9 cmH2O (152% do predito) e P Emáx=141,1±10,2 cmH2O (98,5% do predito) dentro dos limites de normalidade ou acima, enquanto no grupo de obesas mórbidas os valores de P Imáx=66±18,7 cmH2O (84,3% do predito) e P Emáx=78,4±14,2 cmH2O (54,3% do predito) foram inferiores aos preditos. Comparando-se as pressões respiratórias estáticas máximas obtidas de MO com ME, observa-se diferença significativa tanto para os valores de P Imáx (66±18,7 versus 119±1,9 cmH2O) como P Emáx (78,4±14,2 versus 141,14±10,20) com significância estatística de 0,001. Conclui-se que a força muscular respiratória é marcadamente diminuída em MO, quando comparadas a ME.

Effect of three exercise programs on patients with chronic obstructive pulmonary disease

We compared the effect of three different exercise programs on patients with chronic obstructive pulmonary disease including strength training at 50_80% of one-repetition maximum (1-RM) (ST; N = 11), low-intensity general training (LGT; N = 13), or combined training groups (CT; N = 11). Body composition, muscle strength, treadmill endurance test (TEnd), 6-min walk test (6MWT), Saint George's Respiratory Questionnaire (SGRQ), and baseline dyspnea (BDI) were assessed prior to and after the training programs (12 weeks). The training modalities showed similar improvements (P > 0.05) in SGRQ-total (ST = 13 +/- 14%; CT = 12 +/- 14%; LGT = 11 +/- 10%), BDI (ST = 1.8 +/- 4; CT = 1.8 +/- 3; LGT = 1 +/- 2), 6MWT (ST = 43 +/- 51 m; CT = 48 +/- 50 m; LGT = 31 +/- 75 m), and TEnd (ST = 11 +/- 20 min; CT = 11 +/- 11 min; LGT = 7 +/- 5 min). In the ST and CT groups, an additional improvement in 1-RM values was shown (P < 0.05) compared to the LGT group (ST = 10 +/- 6 to 57 +/- 36 kg; CT = 6 +/- 2 to 38 +/- 16 kg; LGT = 1 +/- 2 to 16 +/- 12 kg). The addition of strength training to our current training program increased muscle strength; however, it produced no additional improvement in walking endurance, dyspnea or quality of life. A simple combined training program provides benefits without increasing the duration of the training sessions.

Maximal respiratory static pressures in patients with different stages of COPD severity

BACKGROUND

In this study, we analyzed maximal inspiratory pressure (MIP) and maximal expiratory pressure (MEP) values in a stable COPD population compared with normal subjects. We evaluated the possible correlation between functional maximal respiratory static pressures and functional and anthropometric parameters at different stages of COPD. Furthermore, we considered the possible correlation between airway obstruction and MIP and MEP values.

SUBJECT AND METHODS

110 patients with stable COPD and 21 age-matched healthy subjects were enrolled in this study. Patients were subdivided according to GOLD guidelines: 31 mild, 39 moderate and 28 severe.

RESULTS

Both MIP and MEP were lower in patients with severe airway impairment than in normal subjects. Moreover, we found a correlation between respiratory muscle function and some functional and anthropometric parameters: FEV1 (forced expiratory volume in one second), FVC (forced vital capacity), PEF (peak expiratory flow), TLC (total lung capacity) and height. MIP and MEP values were lower in patients with severe impairment than in patients with a slight reduction of FEV1.

CONCLUSION

The measurement of MIP and MEP indicates the state of respiratory muscles, thus providing clinicians with a further and helpful tool in monitoring the evolution of COPD.

Relationship between peak expiratory flow rate and shoulders posture in healthy individuals and moderate to severe asthmatic patients

INTRODUCTION

Asthma overloads respiratory muscles causing changes in posture.

OBJECTIVES

To evaluate shoulder position in asthmatics and its correlation to the peak expiratory flow rate (PEFR).

METHODS

A cross-sectional study involving 19 asthmatics (study group) and 20 healthy volunteers (control group). Assessment of PEFR was used to determine airway obstruction. Shoulder position was quantified as the ratio between the front and back measurements, in centimeters, of the distance between the two outermost points of each scapula. Shoulder position measurement (SPM) ratio data from both groups were compared and correlated to PEFR.

RESULTS

The asthmatics presented lower PEFR (279 +/- 64 L/min) and SPM (0.88: range 0.83-0.9) than did control subjects (555 +/- 100 L/min and 0.97: range 0.95-1, respectively) (p < 0.001). There was a correlation between PEFR and SPM (asthmatics r = 0.8; controls r = 0.5).

CONCLUSION

Determining SPM ratios allowed us to identify those postural alterations that correlated with pulmonary function in asthmatics and in healthy individuals. Further investigation is needed before SPM can be used as a tool for clinical evaluation of asthma patients.

Relationship of Upper-Limb and Thoracic Muscle Strength to 6-min Walk Distance in COPD Patients

STUDY OBJECTIVES

This study was developed to investigate the influence of thoracic and upper-limb muscle function on 6-min walk distance (6MWD) in patients with COPD.

DESIGN

A prospective, cross-sectional study.

SETTING

The pulmonary rehabilitation center of a university hospital.

PATIENTS

Thirty-eight patients with mild to very severe COPD were evaluated.

MEASUREMENTS AND RESULTS

Pulmonary function and baseline dyspnea index (BDI) were assessed, handgrip strength, maximal inspiratory pressure (Pimax), and 6MWD were measured, and the one-repetition maximum (1RM) was determined for each of four exercises (bench press, lat pull down, leg extension, and leg press) performed on gymnasium equipment. Quality of life was assessed using the St. George Respiratory Questionnaire (SGRQ). We found statistically significant positive correlations between 6MWD and body weight (r = 0.32; p < 0.05), BDI (r = 0.50; p < 0.01), FEV(1) (r = 0.33; p < 0.05), Pimax (r = 0.53; p < 0.01), and all values of 1RM. A statistically significant negative correlation was observed between 6MWD and dyspnea at the end of the 6-min walk test (r = - 0.29; p < 0.05), as well as between 6MWD and the SGRQ activity domain (r = - 0.45; p < 0.01) and impact domain (r = - 0.34; p < 0.05) and total score (r = - 0.40; p < 0.01). Multiple regression analysis selected body weight, BDI, Pimax, and lat pull down 1RM as predictive factors for 6MWD (R(2) = 0.589).

CONCLUSIONS

The results of this study showed the importance of the skeletal musculature of the thorax and upper limbs in submaximal exercise tolerance and could open new perspectives for training programs designed to improve functional activity in COPD patients.

Management of Oropharyngeal and Tracheobronchial Secretions in Patients with Neurologic Disease

BACKGROUND

Neurologic disorders may impair the normal clearance of secretions. Effective palliation requires the management of excessive oral, pharyngeal and/or tracheobronchial secretions. This requires an understanding of underlying mechanisms and familiarity with the many available medical and surgical treatment options.

OBJECTIVES

The authors intend to review the relevant anatomy and physiology along with the available medical, surgical and physical therapies available to treat this commonly encountered problem.

DESIGN

A review of current management and the supporting literature.

CONCLUSIONS

Clinicians have many effective therapeutic options to choose from when managing the excessive oral, pharyngeal and/or tracheobronchial secretions caused by neurologic disorders. Treatment choices that are predicated upon pathophysiologic causes and patient status are the most likely to succeed.

Breathing type and body position effects on sternocleidomastoid and suprahyoid EMG activity

The objective of this study was to determine the effects of breathing type and body position on sternocleidomastoid and suprahyoid electromyographic (EMG) activity. The sample included 18 subjects with upper costal breathing type (study group) and 15 subjects with costo-diaphragmatic breathing type (control group). All individuals had natural dentition and bilateral molar support. EMG recordings at rest and while swallowing saliva were carried out by placing surface electrodes on the left sternocleidomastoid and left suprahyoid muscles. EMG activity was recorded while standing, seated upright, and in the lateral decubitus position. Upper costal breathing type subjects showed a significantly higher suprahyoid EMG activity at rest than costo-diaphragmatic subjects in all body positions studied (mixed model with unstructured covariance matrix). In the lateral decubitus position, both breathing types showed a significantly higher sternocleidomastoid EMG activity at rest and while swallowing saliva. The suprahyoid muscles demonstrated a significantly higher EMG activity at rest as well as in the lateral decubitus position (mixed model with unstructured covariance matrix). These results are relevant because sternocleidomastoid and suprahyoid muscles play an important role in controlling the head posture and mandible dynamics. The neurophysiological mechanisms involved are discussed.

Impaired Respiratory and Skeletal Muscle Strength in Patients Prior to Hematopoietic Stem-Cell Transplantation

STUDY OBJECTIVES

The primary aim was to determine if respiratory and skeletal muscle strength and submaximal exercise capacity were reduced in subjects prior to sibling- or unrelated-donor hematopoietic stem-cell transplantation (HSCT).

DESIGN

Prospective observational study.

SETTING

Tufts-New England Medical Center, a tertiary referral center in Boston, MA.

PATIENTS

All patients (n = 56) undergoing either sibling- or unrelated-donor HSCT from January 1, 2002, to December 31, 2002.

MEASUREMENTS

Demographic data, chemotherapy burden, pulmonary function tests (PFTs), maximal inspiratory muscle strength (PImax), maximal expiratory muscle strength (PEmax), dominant hand grip strength (GS), 6-min walk test (6MWT), and survival as of May 21, 2004.

RESULTS

PImax was reduced to < 80% predicted in 42% of subjects and to < 60% predicted in 18% of subjects. PEmax was reduced to < 80% predicted in 89% of subjects and to < 60% of predicted in 80% of subjects. A significant correlation was observed between PImax and PEmax (r = 0.65, p < 0.0001). GS was reduced to < 80% predicted in 39% of subjects and < 60% predicted in 15% of subjects. The 6MWT was reduced to < 80% predicted in 58% of subjects and to < 60% predicted in 9.6% of subjects. Diffusing capacity of the lung for carbon monoxide (Dlco) was the only PFT that was significantly correlated with 6MWT distance (r = 0.44, p = 0.015). The mean calculated load of chemotherapy was 14.8 +/- 16.5 U (+/- SD). The mean time elapsed from date of hematologic diagnosis to date of HSCT was 874 +/- 1,109 days. The median survival of the cohort was 374 days (95% confidence interval, 177 to 665 days). Respiratory or skeletal muscle strength, 6MWT distance, or calculated burden of chemotherapy did not predict survival.

CONCLUSIONS

Respiratory and skeletal muscle strength and submaximal exercise capacity are reduced in a significant percentage of patients prior to undergoing HSCT. These observations may help explain musculoskeletal weakness that has been reported in the posttransplant period.

Functional magnetic stimulation of expiratory muscles: a noninvasive and new method for restoring cough

The purpose of this study was to assess the effectiveness of functional magnetic stimulation (FMS) for producing expiratory function in normal human subjects. Twelve able-bodied normal subjects were recruited for this study. FMS of the expiratory muscles was performed by using a magnetic stimulator and placing the magnetic coil along the lower thoracic spine. Results showed that peak expired pressure, volume, and flow rate generated by FMS at the end of normal inspiration (102.5 +/- 13.62 cmH2O, 1.6 +/- 0.16 liters, and 4.8 +/- 0.35 l/s, respectively) were comparable to their voluntary maximal levels (P > 0.1). The optimal coil placement was between T7 and T11, and the optimal stimulation parameters were a frequency of 25 Hz and 70-80% of maximal intensity. We conclude that 1) FMS of the lower thoracic nerves in normal subjects resulted in a significant expiratory function comparable to their voluntary maximum; 2) FMS was noninvasive and was well tolerated by all subjects; and 3) FMS may be useful to produce cough in patients in critical care or perioperative settings, or in patients with neurological disorders.

[Diaphragm paralysis as a complication of internal jugular vein puncture]

Rare complications of using the internal jugular vein for vascular access are related to puncture of neighboring organs or other structures. We report the atypical case of a 55-years-old woman with unilateral diaphragm paralysis attributed to accidental damage of the phrenic nerve during an attempt to canalize the internal jugular vein. Other more common causes were ruled out. The severe restrictive ventilatory changes produced had only minor clinical and gasometric repercussions, as previous function was normal and no acute or chronic respiratory disease was present. When ventilation is already compromised, however, this event could seriously worsen the patient's condition.