Efeitos da pressão positiva expiratória nas vias aéreas sobre a atividade eletromiográfica da musculatura acessória da inspiração em portadores de DPOC

Breathing better: A tech-monitored study of positive expiratory pressure and reading aloud for chronic obstructive pulmonary disease

BACKGROUND

Breathing exercises, such as diaphragmatic breathing and positive expiratory pressure (PEP), relieve breathlessness in people with chronic obstructive pulmonary disease (COPD).

AIM

This study aimed to investigate the effects of breathing exercises with PEP and reading aloud on vital signs, fatigue level, severity of dyspnoea and respiratory function parameters in patients with COPD.

DESIGN

The study followed a randomized controlled trial of COPD patients from a single hospital in eastern Turkey.

METHODS

The study included 103 patients who were randomly assigned to receive pre-reading exercises, breathing exercises with a PEP device or no intervention for 8 weeks.

RESULTS

The use of a PEP device improved oxygen saturation, forced expiratory volume in 1 s (FEV1 ) and FEV1 /forced vital capacity (FVC) values and reduced fatigue and dyspnoea severity. Reading aloud lowered the mean arterial pressure and reduced fatigue and dyspnoea severity.

CONCLUSION

The study concludes that PEP devices and reading aloud can improve respiratory function in patients with COPD. Additionally, reading aloud is an accessible, easy-to-implement and economically feasible method for treating COPD symptoms.

Surface electromyography in inspiratory muscles in adults and elderly individuals: A systematic review

INTRODUCTION

Electromyography (EMG) helps to evaluate disorders and pulmonary behavior, as impairments in respiratory muscle function are associated with the development of diseases. There is a wide range of methods and protocols used to record and analyze EMG obtained from respiratory muscles, demonstrating a lack of standardization.

OBJECTIVE

To identify the most common procedures used to record surface EMG (sEMG) of inspiratory muscles in adults and elderly individuals through a systematic review (primary), and to evaluate the quality of the report presented by the studies (secondary).

METHOD

Studies published from January 1995 until June 2018 were searched for in the Web of Science, PubMed, LILACS, EBSCO and Embase databases. Only studies evaluating sEMG of inspiratory muscles were included.

RESULTS

The electronic search retrieved a total of 6697 titles and 92 of them were included. A great variability on the methods applied to both recording and processing/analyzing data was found. Therefore, the synthesis of practical/clinical evidence to support immediate recommendations was impaired. In general, the descriptions presented by the studies are poor.

CONCLUSION

The most common procedures used for sEMG were identified. Methodological studies with objective comparisons were fundamental for improving standardization, given the impossibility of recommendations from this review.

CPAP and EPAP elicit similar lung deflation in a non-equivalent mode in GOLD 3-4 COPD patients

INTRODUCTION

Lung hyperinflation is associated with inspiratory muscle strength reduction, nocturnal desaturation, dyspnea, altered cardiac function and poor exercise capacity in advanced COPD.

OBJECTIVES

We investigated the responses of inspiratory capacity (IC) and inspiratory muscle strength (PImax), comparing continuous positive airway pressure (CPAP) and expiratory positive airway pressure (EPAP) with the main hypothesis that there would be similar effects on lung deflation.

METHODS

Eligible patients were submitted to 10 cmH₂ O CPAP and EPAP on different days, under careful ECG (HR) and peripheral oxygen saturation (SpO₂ ) monitoring.

RESULTS

Twenty-one eligible COPD patients were studied (13 male/8 female, FEV₁ % predicted of 36.5 ± 9.8). Both CPAP and EPAP demonstrated significant post-pre (Δ) changes for IC and PImax, with mean ΔIC for CPAP and EPAP of 200 ± 100 mL and 170 ± 105 mL (P = .001 for both) in 13 and 12 patients (responders) respectively. There were similar changes in % predicted IC and PImax (∼7%, P = .001 for both) for responders and poor responder/non-responder agreement depending on CPAP/EPAP mode (Kappa = .113, P = .604). There were no differences in CPAP and EPAP regarding intensity of lung deflation (P =.254) and no difference was measured regarding HR (P = .235) or SpO₂ (P = .111)_. CONCLUSIONS: Both CPAP and EPAP presented a similar effect on lung deflation, without guaranteeing that the response to one modality would be predictive of the response to the other.

Acute effects of Expiratory Positive Airway Pressure (EPAP) on different levels in ventilation and electrical activity of sternocleidomastoid and parasternal muscles in Chronic Obstructive Pulmonary Disease (COPD) patients: a randomized controlled trial

Objective

To investigate the acute effects of EPAP on the activity of sternocleidomastoid (SCM), parasternal muscles and ventilatory parameters in COPD patients.

Method

Twenty-four patients with COPD were studied using surface electromyography (sEMG) and a ventilometer. Patients were randomly assigned to EPAP 10 cmH₂O-EPAP₁₀ or 15 cmH₂O-EPAP₁₅ for 20 minutes.

Results

The parasternal muscle sEMG activity increased during EPAP₁₀ and EPAP₁₅; however, a greater and significant increase was observed with EPAP₁₀ (mean between-group difference: 12.5% RMS, 95% CI: 9.5 to 15.4, p<0.001). In relation to the baseline, at 10 and 20 minutes and upon recovery, respectively parasternal activity increased by 23.9%, 28.9% and 19.1% during EPAP₁₀ and by 10.7% at 10 and 20 minutes and upon recovery, respectively, 11.4% and 6.9% during EPAP₁₅ at 10 and 20 minutes and upon recovery, respectively. The sEMG activity of SCM muscle showed an opposite pattern, increasing with EPAP₁₅ and decreasing with EPAP₁₀ (mean between-group difference: 15.5% RMS, 95% CI: 12.6 to 18.4, p<0.001). SCM muscle activity during EPAP₁₅, increased by 4.8% and 6.1% at 10 and 20 minutes and decreased by -4.0% upon recovery compared to decreases of –5.6%, –20.6% and –21.3% during EPAP₁₀ at 10, 20 minutes, and recovery. Ventilation at both EPAP intensities promoted significant reductions in respiratory rate (RR) and dyspnea, more pronounced in EPAP₁₅: RR (mean between-group difference: –3,8bpm, 95%CI: –7,5 to –0,2, p=0,015) and dyspnea (mean between-group difference: –1.01, 95%CI: –1.4 to –0.53, p=0.028) .

Conclusion

In COPD patients, the use of EPAP₁₀ was more effective in reducing accessory inspiratory activity and increasing parasternal activity, which was accompanied by an improvement in ventilation and a reduction in dyspnea.

Pressão expiratória positiva nas vias aéreas não reproduz as respostas de frequência cardíaca à manobra de Valsalva em homens jovens saudáveis

A pressão expiratória positiva nas vias aéreas (EPAP) é um recurso terapêutico que compreende uma inspiração seguida de expiração contra resistência. Sua aplicação promove ajustes no sistema cardiovascular, de maneira similar ao observado durante a manobra de Valsalva (MV). O objetivo deste estudo foi analisar a resposta da frequência cardíaca (FC) à MV e às diferentes formas de aplicação de EPAP a fim de identificar se e em qual condição esta técnica reproduz a resposta da FC observada na MV, em homens jovens aparentemente saudáveis. Foram estudados 10 sujeitos (24±3 anos; 25±3 kg/m²) que realizaram os procedimentos de MV e EPAP, aleatoriamente em dias diferentes. Na MV o esforço expiratório foi sustentado por 15 s (pressão oral de 40 mmHg [53,4 cmH2O]). Empregou-se duas técnicas de EPAP (isolada e terapêutica) contra 3 níveis de pressão (10, 15 e 20 cmH2O), aplicados aleatoriamente. As manobras foram repetidas três vezes com intervalo de cinco minutos. Considerou-se o maior valor de variação da FC (DFC) de cada manobra para análise. Empregou-se o teste Shapiro-Wilk para verificar a distribuição dos dados e ANOVA para medidas repetidas, com post-hoc de Fisher, considerando-se α<0,05. Os valores de DFC observados na MV foram maiores (p<0,05) que os encontrados nas diferentes técnicas de EPAP, independentemente do nível pressórico empregado. A aplicação de EPAP, nos três níveis pressóricos, gera menor sobrecarga cardíaca e não reproduz as respostas da FC observadas na MV.