Effects of ventilation mode and manual chest compression on flow bias during the positive end- and zero end-expiratory pressure manoeuvre in mechanically ventilated patients: a randomised crossover trial.

OBJECTIVES: To investigate the effects of ventilation mode and manual chest compression (MCC) application on the flow bias generated during positive end-expiratory pressure-zero end-expiratory pressure (PEEP-ZEEP) in mechanically ventilated patients. PEEP-ZEEP is an airway clearance manoeuvre with the potential to exceed the flow bias required to remove secretions. However, the ventilation mode applied during the manoeuvre has not been standardised. DESIGN: Randomised crossover trial. PARTICIPANTS: Nineteen mechanically ventilated patients. INTERVENTIONS: Patients were randomised to receive PEEP-ZEEP in volume-controlled and pressure-controlled modes, and with or without MCC. MAIN OUTCOME MEASURES: The difference in flow bias - assessed by the peak expiratory flow (PEF) and peak inspiratory flow (PIF) ratio and difference - between PEEP-ZEEP applied in both ventilation modes, and with and without MCC. RESULTS: The expiratory flow bias was significantly higher in the volume-controlled mode than the pressure-controlled mode. This result was caused by a lower PIF in the volume-controlled mode. PEEP-ZEEP applied in the pressure-controlled mode did not achieve the PEF-PIF difference threshold to clear mucus. Moreover, in the majority of cycles of PEEP-ZEEP applied in the pressure-controlled mode, an inspiratory flow bias was generated, which might embed mucus. PEF was 8l/minute higher with MCC compared with without MCC, which increased the PEF-PIF difference by the same amount. No haemodynamic or respiratory adverse effects were found. CONCLUSIONS: If applied in the volume-controlled mode, PEEP-ZEEP can achieve the flow bias needed to expel pulmonary secretions. However, this is not the case in the pressure-controlled mode. MCC can augment the flow bias generated by PEEP-ZEEP, but its application may be dispensable. CLINICAL TRIAL REGISTRATION: http://www.ensaiosclinicos.gov.br/rg/RBR-223xv8/.

Acute Effects of Oscillatory PEP and Thoracic Compression on Secretion Removal and Impedance of the Respiratory System in Non-Cystic Fibrosis Bronchiectasis.

BACKGROUND: Bronchiectasis is characterized by abnormal and permanent dilatation of the bronchi, caused mainly by the progression of inflammatory processes and loss of the ability to remove mucus. Techniques to clear the airways are essential for the treatment of these patients. In this study, we aimed to evaluate the acute effects of oscillatory PEP and thoracic compression on both the clearance of secretions and impedance of airways in subjects with bronchiectasis. METHODS: This was a randomized crossover single-blinded study that involved both subjects with bronchiectasis and healthy subjects evaluated by using an impulse oscillometry system, which assessed resistance at 5 Hz and resistance 20 Hz, reactance at 5 Hz, reactance area, and resonant frequency, before, after, and 30 min after oscillatory PEP, chest compression, or control sessions. Dry and total weights, adhesiveness, purulence of the expectorated secretions, the dyspnea scale score, the acceptability and tolerance scale score, pulse oximetry, and difficulty in expectoration were also assessed. RESULTS: The dry and total weights of secretions were higher after the use of the oscillatory PEP technique than those in a control session (P = .005 and P = .039, respectively). In the bronchiectasis group, there was a decrease after oscillatory PEP in total airway resistance (P = .04), peripheral resistance (P = .005), and reactance area (P = .001). After compression, there was a decrease in peripheral resistance Hz (P = .001) and reactance area (P = .001). In the healthy group, there was an increase in resistance at 5 Hz (P = .02) after oscillatory PEP. There were no differences in acceptability and tolerance, dyspnea, and oxygen saturation. CONCLUSIONS: The oscillatory PEP technique was effective for the removal of secretions and in decreasing total and peripheral respiratory system resistance; thoracic compression had comparable positive effects on the peripheral resistance. Both techniques were safe and well tolerated by the subjects with bronchiectasis. ClinicalTrials.gov registration NCT02509637.).

Oscilometria de impulso e espirometria em escolares submetidos ao teste de caminhada de seis minutos / Impulse oscillometry and spirometry in schoolers submitted to the six-minute walk test

RESUMO Objetivo: Verificar as repercussões do teste de esforço submáximo na mecânica respiratória e na função pulmonar de escolares. Métodos: Estudo transversal com escolares de 7 a 14 anos submetidos à avaliação da mecânica respiratória por sistema de oscilometria de impulso (IOS) e da função pulmonar pela espirometria. Realizou-se também o teste de caminhada de seis minutos (TC6), todos segundo os padrões da Sociedade Torácica Americana. O TC6 foi executado duas vezes com intervalo de 30 minutos entre cada teste. O IOS e a espirometria foram feitos antes do primeiro TC6 (pré-TC6) e repetidos imediatamente após o primeiro TC6 (pós-TC61) e após o segundo TC6 (pós-TC62). A comparação dos resultados nos três tempos do estudo se deu por análise de variância para medidas repetidas (teste post-hoc de Bonferroni) ou teste de Friedman, sendo significante p≤0,05. Resultados: Participaram 21 sujeitos; 53% masculinos e idade média de 10,9±2,3 anos. Encontraram-se diferenças entre resistência total (R5) e resistência central das vias aéreas (R20) nos 3 tempos do estudo (p=0,025 e p=0,041, respectivamente). A análise post-hoc indicou aumento de resistência R5 entre pré-TC6 e pós-TC61 (R5=0,540±0,100 versus 0,590±0,150 kPa/L/s, p=0,013; e R20=0,440±0,800 versus 0,470±0,100 kPa/L/s, p=0,038). A única variável espirométrica com alteração no decorrer do tempo foi o fluxo expiratório forçado 25-75% (FEF25-75%) (p=0,003). Conclusões: As repercussões encontradas foram: aumento da resistência total e da resistência central das vias aéreas e redução do FEF25-75% após o TC6 em escolares, sugerindo a necessidade de mais atenção na realização de testes submáximos em crianças com alguma predisposição a alterações das vias aéreas.

ABSTRACT Objective: To verify repercussions of submaximal exercise testing on respiratory mechanics and pulmonary function in schoolchildren. Methods: Cross-sectional study, with children aged 7 to 14 years, who had their respiratory mechanics assessed by impulse oscillometry (IOS), and pulmonary function by spirometry. They performed the six-minute walk test (6MWT), as per the standards by the American Thoracic Society. The 6MWT was performed twice with a 30-minute interval. IOS and spirometry were performed before the first 6MWT (Pre-6MWT) and immediately after the first (Post-6MWT1) and second walking tests (Post-6MWT2). The results in these three phases were compared by analysis of variance for repeated measures (post-hoc Bonferroni test) or by the Friedman's test, with p≤0.05 considered significant. Results: Twenty-one subjects participated in the study: 53% were males and mean age was 10.9±2.3 years. There were differences between total resistance (R5) and central airway resistance (R20) at the three phases of assessment (p=0.025 and p=0.041, respectively). Post-hoc analysis indicated increase in R5 when Pre-6MWT and Post-6MWT1 were compared (R5=0.540±0.100 versus 0.590±0.150 kPa/L/s, p=0.013; and R20=0.440±0.800 versus 0.470±0.100 kPa/L/s, p=0.038). Forced expiratory flow 25-75% (FEF25-75%) changed over time (p=0.003). Conclusions: Repercussions were: increase in central and total airway resistance and reduction of FEF25-75% after 6MWT in schoolchildren, suggesting that greater attention should be given to submaximal tests in children with predisposition to airways alterations.

IMPULSE OSCILLOMETRY AND SPIROMETRY IN SCHOOLERS SUBMITTED TO THE SIX-MINUTE WALK TEST. / OSCILOMETRIA DE IMPULSO E ESPIROMETRIA EM ESCOLARES SUBMETIDOS AO TESTE DE CAMINHADA DE SEIS MINUTOS.

OBJECTIVE: To verify repercussions of submaximal exercise testing on respiratory mechanics and pulmonary function in schoolchildren. METHODS: Cross-sectional study, with children aged 7 to 14 years, who had their respiratory mechanics assessed by impulse oscillometry (IOS), and pulmonary function by spirometry. They performed the six-minute walk test (6MWT), as per the standards by the American Thoracic Society. The 6MWT was performed twice with a 30-minute interval. IOS and spirometry were performed before the first 6MWT (Pre-6MWT) and immediately after the first (Post-6MWT1) and second walking tests (Post-6MWT2). The results in these three phases were compared by analysis of variance for repeated measures (post-hoc Bonferroni test) or by the Friedman's test, with p≤0.05 considered significant. RESULTS: Twenty-one subjects participated in the study: 53% were males and mean age was 10.9±2.3 years. There were differences between total resistance (R5) and central airway resistance (R20) at the three phases of assessment (p=0.025 and p=0.041, respectively). Post-hoc analysis indicated increase in R5 when Pre-6MWT and Post-6MWT1 were compared (R5=0.540±0.100 versus 0.590±0.150 kPa/L/s, p=0.013; and R20=0.440±0.800 versus 0.470±0.100 kPa/L/s, p=0.038). Forced expiratory flow 25-75% (FEF25-75%) changed over time (p=0.003). CONCLUSIONS: Repercussions were: increase in central and total airway resistance and reduction of FEF25-75% after 6MWT in schoolchildren, suggesting that greater attention should be given to submaximal tests in children with predisposition to airways alterations.

OBJETIVO: Verificar as repercussões do teste de esforço submáximo na mecânica respiratória e na função pulmonar de escolares. MÉTODOS: Estudo transversal com escolares de 7 a 14 anos submetidos à avaliação da mecânica respiratória por sistema de oscilometria de impulso (IOS) e da função pulmonar pela espirometria. Realizou-se também o teste de caminhada de seis minutos (TC6), todos segundo os padrões da Sociedade Torácica Americana. O TC6 foi executado duas vezes com intervalo de 30 minutos entre cada teste. O IOS e a espirometria foram feitos antes do primeiro TC6 (pré-TC6) e repetidos imediatamente após o primeiro TC6 (pós-TC61) e após o segundo TC6 (pós-TC62). A comparação dos resultados nos três tempos do estudo se deu por análise de variância para medidas repetidas (teste post-hoc de Bonferroni) ou teste de Friedman, sendo significante p≤0,05. RESULTADOS: Participaram 21 sujeitos; 53% masculinos e idade média de 10,9±2,3 anos. Encontraram-se diferenças entre resistência total (R5) e resistência central das vias aéreas (R20) nos 3 tempos do estudo (p=0,025 e p=0,041, respectivamente). A análise post-hoc indicou aumento de resistência R5 entre pré-TC6 e pós-TC61 (R5=0,540±0,100 versus 0,590±0,150 kPa/L/s, p=0,013; e R20=0,440±0,800 versus 0,470±0,100 kPa/L/s, p=0,038). A única variável espirométrica com alteração no decorrer do tempo foi o fluxo expiratório forçado 25-75% (FEF25-75%) (p=0,003). CONCLUSÕES: As repercussões encontradas foram: aumento da resistência total e da resistência central das vias aéreas e redução do FEF25-75% após o TC6 em escolares, sugerindo a necessidade de mais atenção na realização de testes submáximos em crianças com alguma predisposição a alterações das vias aéreas.

The Role of Multidetector Computed Tomography and the Forced Oscillation Technique in Assessing Lung Damage in Adults With Cystic Fibrosis.

BACKGROUND: With increased survival rates and the consequent emergence of an adult population with cystic fibrosis (CF), developing novel tools for periodic evaluations of these patients has become a new challenge. Thus, we sought to determine the contribution of lung-volume quantification using multidetector computed tomography (CT) in adults with CF and to investigate the association between structural changes and functional abnormalities. METHODS: This was a cross-sectional study in which 21 adults with CF and 22 control subjects underwent lung-volume quantification using multidetector CT. Voxel densities were divided into 4 bands: -1,000 to -900 Hounsfield units (HU) (hyperaerated region), -900 to -500 HU (normally aerated region), -500 to -100 HU (poorly aerated region), and -100 to 100 HU (non-aerated region). In addition, all participants performed pulmonary function tests including spirometry, body plethysmography, diffusion capacity for carbon monoxide, and the forced oscillation technique. RESULTS: Adults with CF had more non-aerated regions and poorly aerated regions with lung-volume quantification using multidetector CT than controls. Despite these abnormalities, total lung volume measured by lung-volume quantification using multidetector CT did not differ between subjects and controls. Total lung capacity (TLC) measured by body plethysmography correlated with both total lung volume (rs = 0.71, P < .001) and total air volume (rs = 0.71, P < .001) as measured with lung-volume quantification using multidetector CT. While the hyperaerated regions correlated with the functional markers of gas retention in the lungs (increased residual volume (RV) and RV/TLC ratio), the poorly aerated regions correlated with the resistive parameters measured by the forced oscillation technique (increased intercept resistance and mean resistance). We also observed a correlation between normally aerated regions and highest pulmonary diffusion values (rs = 0.68, P < .001). CONCLUSIONS: In adults with CF, lung-volume quantification using multidetector CT can destimate the lung volumes of compartments with different densities and determine the aerated and non-aerated contents of the lungs; furthermore, lung-volume quantification using multidetector CT is clearly related to pulmonary function parameters.

Correlations between forced oscillation technique parameters and pulmonary densitovolumetry values in patients with acromegaly.

The aims of this study were to evaluate the forced oscillation technique (FOT) and pulmonary densitovolumetry in acromegalic patients and to examine the correlations between these findings. In this cross-sectional study, 29 non-smoking acromegalic patients and 17 paired controls were subjected to the FOT and quantification of lung volume using multidetector computed tomography (Q-MDCT). Compared with the controls, the acromegalic patients had a higher value for resonance frequency [15.3 (10.9-19.7) vs 11.4 (9.05-17.6) Hz, P=0.023] and a lower value for mean reactance [0.32 (0.21-0.64) vs 0.49 (0.34-0.96) cm H2O/L/s2, P=0.005]. In inspiratory Q-MDCT, the acromegalic patients had higher percentages of total lung volume (TLV) for nonaerated and poorly aerated areas [0.42% (0.30-0.51%) vs 0.25% (0.20-0.32%), P=0.039 and 3.25% (2.48-3.46%) vs 1.70% (1.45-2.15%), P=0.001, respectively]. Furthermore, the acromegalic patients had higher values for total lung mass in both inspiratory and expiratory Q-MDCT [821 (635-923) vs 696 (599-769) g, P=0.021 and 844 (650-945) vs 637 (536-736) g, P=0.009, respectively]. In inspiratory Q-MDCT, TLV showed significant correlations with all FOT parameters. The TLV of hyperaerated areas showed significant correlations with intercept resistance (rs=-0.602, P<0.001) and mean resistance (rs=-0.580, P<0.001). These data showed that acromegalic patients have increased amounts of lung tissue as well as nonaerated and poorly aerated areas. Functionally, there was a loss of homogeneity of the respiratory system. Moreover, there were correlations between the structural and functional findings of the respiratory system, consistent with the pathophysiology of the disease.

Correlations between forced oscillation technique parameters and pulmonary densitovolumetry values in patients with acromegaly

The aims of this study were to evaluate the forced oscillation technique (FOT) and pulmonary densitovolumetry in acromegalic patients and to examine the correlations between these findings. In this cross-sectional study, 29 non-smoking acromegalic patients and 17 paired controls were subjected to the FOT and quantification of lung volume using multidetector computed tomography (Q-MDCT). Compared with the controls, the acromegalic patients had a higher value for resonance frequency [15.3 (10.9-19.7) vs 11.4 (9.05-17.6) Hz, P=0.023] and a lower value for mean reactance [0.32 (0.21-0.64) vs 0.49 (0.34-0.96) cm H2O/L/s2, P=0.005]. In inspiratory Q-MDCT, the acromegalic patients had higher percentages of total lung volume (TLV) for nonaerated and poorly aerated areas [0.42% (0.30-0.51%) vs 0.25% (0.20-0.32%), P=0.039 and 3.25% (2.48-3.46%) vs 1.70% (1.45-2.15%), P=0.001, respectively]. Furthermore, the acromegalic patients had higher values for total lung mass in both inspiratory and expiratory Q-MDCT [821 (635-923) vs 696 (599-769) g, P=0.021 and 844 (650-945) vs 637 (536-736) g, P=0.009, respectively]. In inspiratory Q-MDCT, TLV showed significant correlations with all FOT parameters. The TLV of hyperaerated areas showed significant correlations with intercept resistance (rs=−0.602, P<0.001) and mean resistance (rs=−0.580, P<0.001). These data showed that acromegalic patients have increased amounts of lung tissue as well as nonaerated and poorly aerated areas. Functionally, there was a loss of homogeneity of the respiratory system. Moreover, there were correlations between the structural and functional findings of the respiratory system, consistent with the pathophysiology of the disease.

Analysis of acoustic frequency and wave amplitude generated by the Oscillatory Thoracic Thixotropic Device (Diottix(r)) in human chest / Análisis de la frecuencia acústica y amplitud de las ondas sonoras generadas por el Dispositivo Oscilatorio Torácico Tixotrópico (Diottix(r)) en el tórax humano / Análise da frequência acústica e amplitude das ondas sonoras geradas pelo Dispositivo Oscilatório Torácico Tixotrópico (Diottix(r)) no tórax humano

Diottix(r) was calibrated at 25 Hz to achieve the frequency indicated in literature as being effective to mobilize the airways secretions. However, the amplitude and frequency of the waves generated by the equipment in different regions of the chest still need to be investigated. The objective of this study was to analyze the frequency and amplitude of waves generated by Diottix(r) in chests of healthy subjects. Diottix(r) was used in the anterior and posterior regions of the chest. The mechanical waves were captured using stethoscopes connected to electret microphones, which were connected to a digital oscilloscope. Frequency and amplitude data were recorded by the stethoscope, positioned in six points in the anterior region and six in the posterior region of the chest, following the positions commonly used in pulmonary auscultation. Signals were recorded and transferred to a computer with software for their analysis. The frequency of waves did not present a significant change (from 24.9 to 26.4 Hz). The wave amplitude in the anterior versus the posterior region in each area of the lung, the upper, middle and lower, had differences. Diottix(r) produces frequencies in the chest according to the calibrated; thus, it can be a complementary resource to bronchial hygiene maneuvers. The amplitudes of waves seem to be affected by other structures like bone parts and heart.

Diottix(r) fue calibrado en 25 Hz para alcanzar la frecuencia indicada en la literatura como eficaz para movilizar secreciones de las vías aéreas. La amplitud y frecuencia de ondas generadas por el equipamiento en las diferentes regiones del tórax aun necesitan de más investigaciones. El objetivo de eso estudio fue analizar la frecuencia y amplitud de ondas generadas por el Diottix(r) en el tórax de sujetos saludables. La aplicación del Diottix(r) fue realizada en las regiones anterior y posterior del tórax. Las ondas mecánicas fueron captadas utilizándose estetoscopios ligados a micrófonos de electret, los cuales estaban ligados a uno osciloscopio digital. Los datos de frecuencia y amplitud fueron captados por lo estetoscopio posicionado en seis puntos en la región anterior y seis en la posterior del tórax, siguiendo las posiciones comúnmente utilizadas en la ausculta pulmonar. Los sígnales fueron registrados y transferidos para una computadora a través de un programa para su análisis de datos. La frecuencia de ondas no presentó variación significativa (del 24,9 al 26,4 Hz). La amplitud de onda en la región anterior versus posterior en cada segmento del pulmón, tercio superior, medio e inferior, presentó diferencia. Lo Diottix(r) produce frecuencias en el tórax según el calibrado. Por lo tanto, puede ser uno recurso complementar a las manobras de higiene de los bronquios. Las amplitudes de ondas parecen ser afectadas por otras estructuras, las cuales incluyen partes óseas y el corazón.

O Diottix(r) foi calibrado a 25 Hz para atingir a frequência indicada na literatura como eficaz a fim de mobilizar secreções de vias aéreas. A amplitude e a frequência das ondas geradas pelo equipamento nas diferentes regiões do tórax ainda precisam ser investigadas. O objetivo de estudo foi analisar a frequência e a amplitude das ondas geradas pelo Diottix(r) no tórax de indivíduos saudáveis. A aplicação do Diottix(r) foi realizada nas regiões anterior e posterior do tórax. As ondas mecânicas foram captadas utilizando estetoscópios conectados a microfones de eletreto, os quais estavam ligados a um osciloscópio digital. Os dados de frequência e amplitude foram captados pelo estetoscópio, posicionado em seis pontos na região anterior e seis na posterior do tórax, seguindo as posições comumente utilizadas na ausculta pulmonar. Os sinais foram registrados e transferidos para um computador por meio de um software para análise deles. A frequência das ondas não apresentou variação significativa (24,9 a 26,4 Hz). A amplitude de onda na região anterior versus posterior em cada segmento do pulmão, terço superior, médio e inferior, apresentou diferença. O Diottix(r) produz frequências no tórax de acordo com o calibrado; desta forma, pode ser um recurso complementar às manobras de higiene brônquica. As amplitudes de ondas parecem ser afetadas por outras estruturas, que incluem as partes ósseas e o coração.

Use of air stacking and abdominal compression for cough assistance in people with complete tetraplegia.

STUDY DESIGN: Cross-sectional. OBJECTIVE: To assess cough using air stacking (AS) to assist inspiratory volume with abdominal compression (AC) during expiration in patients with American Spinal Injury Association Impairment Scale (AIS) A. SETTING: Large tertiary hospital in Chile. METHODS: Peak cough flow (PCF) was measured during four different interventions: spontaneous maximal expiratory effort (MEE); MEE while receiving AC (MEE-AC); MEE after AS with a manual resuscitation bag (AS-MEE); and MEE with AS and AC (AS-MEE-AC). RESULTS: Fifteen in-patients with complete tetraplegia (C4-C6) were included. Median age was 33 years (16-56). PCF during the different interventions was PCF for MEE was 183±90 l min(-1); PCF for MEE-AC was 273±119 l min(-1); PCF for AS-MEE was 278±106 l min(-1) and PCF for AS-MEE-AC was 368±129 l min(-1). We observed significant differences in PCF while applying MEE-AC and AS-MEE compared with MEE (P=0.0001). However, the difference in PCF value was greater using the AS-MEE-AC technique (P=0.00001). CONCLUSION: Patients with spinal cord injury (SCI) presented an ineffective cough that constitutes a risk factor for developing respiratory complications. The application of combined techniques (AS-MEE-AC) can reach near normal PCF values. This is a low-cost, simple and easily applied intervention that could be introduced to all patients with tetraplegia.

Effects of manual chest compression and descompression maneuver on lung volumes, capnography and pulse oximetry in patients receiving mechanical ventilation / Efeitos da manobra de compressão e descompressão torácica nos volumes pulmonares, capnografia e oximetria de pulso em pacientes submetidos à ventilação mecânica

OBJECTIVES: The aims of this study were to evaluate whether there are changes in lung volumes, capnography, pulse oximetry and hemodynamic parameters associated with manual chest compression-decompression maneuver (MCCD) in patients undergoing mechanical ventilation (MV). Method: A prospective study of 65 patients undergoing to MV after 24 hours. All patients received bronchial hygiene maneuvers and after 30 minutes they were submitted to ten repetitions of the MCCD during 10 consecutive respiratory cycles in the right hemithorax and than in the left hemithorax. The data were collected before the application of the maneuver and after 1, 5, 10, 15, 20, 25, 30, 35 and 40 minutes following application of the maneuver. RESULTS: There were statistical significant (p<0.0001) improvements in the following parameters after MCCD maneuver during all phases of data collection until 40 minutes: inspiratory tidal volume (baseline: 458.2±132.1 ml; post 1 min: 557.3±139.1; post 40 min: 574.4±151), minute volume (baseline: 7.0±2.7 L/min; post 1 min: 8.7±3.3; post 40 min: 8.8±3.8), and pulse oximetry (baseline: 97.4±2.2%; post 1 min: 97.9±1,8; post 40 min: 98.2±1.6; p<0.05). There was a reduction in CO2 expired (baseline: 35.1±9.0 mmHg; post 1 min: 31.5±8.2; post 40 min: 31.5±8.29; p<0.0001). There was no statically significant changes in heart rate (baseline: 94.5±20.5 mmHg; post 1 min: 94.7±20.5; post 40 min: 94.92±20.20; p=1) and mean arterial pressure (baseline: 91.2±19.1 bpm; post 1 min: 89.5±17.7; post 40 min: 89.01±16.88; p=0.99). The variables were presented in terms of means and standard deviations. CONCLUSION: The MCCD maneuver had positive effects by increasing lung volume and pulse oximetry and reducing CO2 expired, without promoting hemodynamic changes in patients undergoing mechanical ventilation.

OBJETIVOS: Avaliar a presença de alterações nos volumes pulmonares, oximetria de pulso, capnografia e alterações hemodinâmicas associadas à intervenção da manobra de compressão e descompressão torácica (MCDT) nos pacientes submetidos à ventilação mecânica (VM). Método: Tratou-se de um estudo prospectivo em que foram incluídos 65 pacientes em VM há mais de 24 horas. O protocolo consistiu na aplicação de manobras de higiene brônquica e, após 30 minutos, os pacientes eram submetidos a dez repetições da MCDT em dez respirações consecutivas no hemitórax direito e, posteriormente, no hemitórax esquerdo, coletando os dados antes e após a aplicação da manobra nos tempos 1, 5, 10, 15, 20, 25, 30, 35 e 40 minutos. RESULTADOS: Constatou-se aumento significante (p<0,001) do volume corrente inspiratório (pré: 458,2±132,1 ml; pós 1 minuto: 557,3±139,1; pós 40 minutos: 574,4±151), volume minuto corrente (pré: 7,0±2,7 L/min; pós 1 minuto: 8,7±3,3; pós 40 minutos: 8,8±3,8) e oximetria de pulso (pré: 97,4±2,2%; pós 1 minuto: 97,9±1,8; pós 40 minutos: 98,2±1,6; p<0,05). Ocorreu redução no CO2 expirado (pré: 35,1±9,0 mmHg; pós 1 minuto: 31,5±8,2; pós 40 minutos: 31,5±8,29; p<0.0001). Não houve alteração significante da frequência cardíaca (pré: 94,5±20,5 mmHg; pós 1 minuto: 94,7±20,5 e pós 40 minutos: 94,9±20,2; p=1) e pressão arterial média (pré: 91,2±19,1 bpm; pós 1 minuto: 89,5±17,7 e pós 40 minutos: 89,0±16,8; p=0,99). As variáveis foram expressas em média e desvio-padrão. CONCLUSÃO: A MCDT possibilita a otimização dos volumes pulmonares, da oximetria de pulso e a redução do CO2 expirado sem promover alterações hemodinâmicas significantes nos pacientes submetidos à ventilação mecânica.

Effects of manual chest compression and descompression maneuver on lung volumes, capnography and pulse oximetry in patients receiving mechanical ventilation.

OBJECTIVES: The aims of this study were to evaluate whether there are changes in lung volumes, capnography, pulse oximetry and hemodynamic parameters associated with manual chest compression-decompression maneuver (MCCD) in patients undergoing mechanical ventilation (MV). METHOD: A prospective study of 65 patients undergoing to MV after 24 hours. All patients received bronchial hygiene maneuvers and after 30 minutes they were submitted to ten repetitions of the MCCD during 10 consecutive respiratory cycles in the right hemithorax and than in the left hemithorax. The data were collected before the application of the maneuver and after 1, 5, 10, 15, 20, 25, 30, 35 and 40 minutes following application of the maneuver. RESULTS: There were statistical significant (p<0.0001) improvements in the following parameters after MCCD maneuver during all phases of data collection until 40 minutes: inspiratory tidal volume (baseline: 458.2±132.1 ml; post 1 min: 557.3±139.1; post 40 min: 574.4±151), minute volume (baseline: 7.0±2.7 L/min; post 1 min: 8.7±3.3; post 40 min: 8.8±3.8), and pulse oximetry (baseline: 97.4±2.2%; post 1 min: 97.9±1,8; post 40 min: 98.2±1.6; p<0.05). There was a reduction in CO2 expired (baseline: 35.1±9.0 mmHg; post 1 min: 31.5±8.2; post 40 min: 31.5±8.29; p<0.0001). There was no statically significant changes in heart rate (baseline: 94.5±20.5 mmHg; post 1 min: 94.7±20.5; post 40 min: 94.92±20.20; p=1) and mean arterial pressure (baseline: 91.2±19.1 bpm; post 1 min: 89.5±17.7; post 40 min: 89.01±16.88; p=0.99). The variables were presented in terms of means and standard deviations. CONCLUSION: The MCCD maneuver had positive effects by increasing lung volume and pulse oximetry and reducing CO2 expired, without promoting hemodynamic changes in patients undergoing mechanical ventilation.

The influence of Flutter®VRP1 components on mucus transport of patients with bronchiectasis.

BACKGROUND: The Flutter(®)VRP1 combines high frequency oscillation and positive expiratory pressure (PEP). OBJECTIVE: To separately evaluate the effect of the Flutter(®)VRP1 components (high frequency oscillation and PEP) on mucus transportability in patients with bronchiectasis. METHODS: Eighteen patients with bronchiectasis received sessions with the Flutter(®)VRP1 or PEP for 30 min daily in a randomized, crossover study. The treatment duration was four weeks with one of the therapies, one week of a "wash-out" period and followed by four more weeks with the other treatment. Weekly secretion samples were collected and evaluated for mucociliary relative transport velocity (RTV), displacement in a simulated cough machine (SCM) and contact angle measurement (CAM). For the proposed comparisons, a linear regression model was used with mixed effects with a significance level of 5%. RESULTS: The Flutter(®)VRP1 treatment resulted in greater displacement in SCM and lower CAM when comparing results from the first (9.6 ± 3.4 cm and 29.4 ± 5.7°, respectively) and fourth weeks of treatment (12.44 ± 10.5 cm and 23.28 ± 6.2°, respectively; p < 0.05). There was no significant difference in the RTV between the treatment weeks for either the Flutter(®)VRP1 or PEP. CONCLUSION: The use of the Flutter(®)VRP1 for four weeks is capable of altering the respiratory secretion transport properties, and this alteration is related to the high frequency oscillation component.

Fisioterapia respiratória na fibrose cística / Respiratory physiotherapy in cystic fibrosis

A fisioterapia torácica convencional (FTC) foi introduzida na década de 1950 como padrão-ouro nos cuidados dos pacientes com fibrose cística (FC), no entanto há poucas evidências para que seu uso seja mantido na rotina diária. Neste trabalho, revisamos a evolução das condutas fisioterapêuticas em pacientes portadores de FC, bem como as novas opções de tratamento, com base nas evidências descritas na literatura nos últimos anos. Na últimas décadas, a fisioterapia respiratória modificou-se consideravelmente introduziu-se novas abordagens, tais como técnicas ativas, os pacientes são mantidos em posições mais confortáveis, que se mostram mais eficazes do que as convencionais. Entre elas, destacamos a pressão expiratória positiva (PEP), PEP oscilatória, ciclo ativo da respiração, aumento do fluxo expiratório, drenagem autógena e drenagem autógena modificada. O paciente deve conhecer e eventualmente participar, juntamente ao profissional, da definição da técnica mais apropriada a seu caso. Para tal, uma boa relação fisioterapeuta-paciente é de fundamental importância.

Conventional chest physiotherapy (CCP) started to be used in the 1950s as the gold standard in the care of patients with cystic fibrosis (CF). However, there is little evidence that its use is maintained in the daily routine. The present review of the literature presents the evolution of the practice of physical therapy in patients with CF, as well as new treatment options based on the evidence described in recent years. In the last decades respiratory physiotherapy has changed considerably. By means of new approaches, such as active techniques, patients are offered more comfortable positions, which are more effective than the conventional ones. Among these techniques, the following are highlighted: positive expiratory pressure (PEP), oscillatory PEP, active cycle of breathing, expiratory flow increase, autogenic drainage, and modified autogenic drainage. Patients must understand the therapy and help the physical therapist to define the most appropriate technique for their cases. A good physical therapistpatient relationship is crucial so that such objective can be achieved.

Mechanical analysis of an oscillatory positive expiratory pressure device used in respiratory rehabilitation.

This article aims to characterize the mechanical behavior of the Acapella Blue, a respiratory rehabilitation device designed to aid sputum clearance. In this scope, the present study initially describes in detail the peak-to-peak oscillation amplitude (App) and peak frequency (fp) behavior, as well as positive pressure level (Ppl), in the flow range more comonly found in practice. The parameters were evaluated in all 5 adjustment levels of the equipment in intervals of 50 mL/s. The device characterization has shown fp up to 23 Hz, App from 0.2 to 2.8 cmH(2)O and Ppl ranging from 1.2 to 13.5 cmH(2)O. The studied device may produce oscillation in the ranges of ciliary movements and respiratory system resonance frequency of patients with respiratory diseases. Data obtained in this work may help to optimize the use of the Acapella Blue device in respiratory rehabilitation. Suggestions for the practical use of the device are also presented.

Air stacking and chest compression increase peak cough flow in patients with Duchenne muscular dystrophy.

OBJECTIVE: To evaluate cough efficiency using two manually-assisted cough techniques. METHODS: We selected 28 patients with Duchenne muscular dystrophy. The patients were receiving noninvasive nocturnal ventilatory support and presented FVC values < 60% of predicted. Peak cough flow (PCF) was measured, with the patient seated, at four time points: at baseline, during a spontaneous maximal expiratory effort (MEE); during an MEE while receiving chest compression; during an MEE after air stacking with a manual resuscitation bag; and during an MEE with air stacking and compression (combined technique). The last three measurements were conducted in random order. The results were compared using Pearson's correlation test and ANOVA with repeated measures, followed by Tukey's post-hoc test (p < 0.05). RESULTS: The mean age of the patients was 20 + or - 4 years, and the mean FVC was 29 + or - 12%. Mean PCF at baseline, with chest compression, after air stacking and with the use of the combined technique was 171 + or - 67, 231 + or - 81, 225 + or - 80, and 292 + or - 86 L/min, respectively. The results obtained with the use of the combined technique were significantly better than were those obtained with the use of either technique alone (F[3.69] = 67.07; p < 0.001). CONCLUSIONS: Both chest compression and air stacking techniques were efficient in increasing PCF. However, the combination of these two techniques had a significant additional effect (p < 0.0001).

Comparison of the effects that two different respiratory physical therapy techniques have on cardiorespiratory parameters in infants with acute viral bronchiolitis.

OBJECTIVE: To compare the expiratory flow increase technique (EFIT) and vibration accompanied by postural drainage (PD) in terms of their effects on the heart rate (HR), respiratory rate (RR) and SpO(2) of infants with acute viral bronchiolitis (AVB). METHODS: Infants with clinical and radiological diagnosis of AVB were analyzed. The HR, RR and SpO(2) were registered at four time points: prior to the procedure; and at 10, 30 and 60 min after the procedure. The patients were divided into three groups: submitted to the EFIT; submitted to vibration/PD; and control. RESULTS: We included 81 infants, 27 per group, with a mean age of 4.52 years and a mean weight of 6.56 kg. Using ANOVA, we found that the EFIT and vibration/PD groups presented no significant differences in relation to the control group in terms of the mean values for HR, RR or SpO(2) (p > 0.05). Considering only the four time points evaluated, the mean RR was significantly lower in the EFIT and vibration/PD groups than in the control group (p < 0.05). CONCLUSIONS: In terms of overall improvement of cardiorespiratory parameters, neither the EFIT nor vibration/PD provided any benefit to infants with BVA. However, over time, respiratory physical therapy seems to contribute to decreasing the RR in these patients.

Laboratory evaluation of the Acapella device: pressure characteristics under different conditions, and a software tool to optimize its practical use.

BACKGROUND: The Acapella is a respiratory rehabilitation device designed to aid sputum clearance. When the patient exhales through this device, continuous and oscillatory pressure levels are produced. The adequate practical use of the Acapella is critically dependent on the characteristics of the produced pressure, which include the production of a mean pressure>or=10 cm H2O and a matching of the oscillation frequency with the respiratory-system resonance frequency, and/or with the frequency of ciliary movement (approximately 13 Hz). The development of a dedicated software tool would contribute to optimize the clinical application of this device. Thus, the aim of this study was 2-fold: to characterize the mechanical behavior of the Acapella, and to develop a software tool to ease the practical use of this device. METHODS: An experimental setup was assembled in order to study mean pressure, oscillation frequency, and the oscillation amplitudes produced by 3 Acapella devices (model green) in the whole range of instrument adjustments and under air flow rates ranging from 200 mL/s to 800 mL/s. In order to increase flexibility, allowing the fast integration of further information obtained in future studies, the software was developed in a graphical environment. RESULTS: The device characterization showed an oscillation frequency varying from 8 Hz to 21 Hz, mean pressure ranging from 3 cm H2O to 23 cm H2O, and oscillation amplitude from 4 cm H2O to 9 cm H2O. These parameters increased with flow and instrument adjustment. A user-friendly software was developed, incorporating the current knowledge concerning secretion removal. After the introduction of the desired frequency and the patient air flow by the user, the software automatically calculates the necessary instrument adjustment, as well as mean pressure and oscillation amplitude. CONCLUSIONS: The Acapella device may produce clinically adequate values of mean pressure and oscillation frequency. However, it depends on its use at optimized conditions. The user-friendly software proposed in this study could help the user to achieve these conditions.

Empilhamento de ar e compressão torácica aumentam o pico de fluxo da tosse em pacientes com distrofia muscular de Duchenne / Air stacking and chest compression increase peak cough flow in patients with Duchenne muscular dystrophy

OBJETIVO: Avaliar a eficiência da tosse através do uso de duas manobras manuais de auxílio à tosse. MÉTODOS: Foram selecionados 28 pacientes portadores de distrofia muscular de Duchenne em uso de ventilação mecânica não-invasiva noturna e CVF < 60 por cento do previsto. O pico de fluxo da tosse (PFT) foi medido, com o paciente sentado, em quatro momentos: com esforço expiratório máximo (EEM) de forma espontânea (basal), EEM associado à compressão torácica, EEM após empilhamento de ar com bolsa de ventilação e EEM com o uso dessas duas técnicas (técnica combinada). As três últimas medições foram realizadas em ordem aleatória. Os resultados foram comparados usando o teste de correlação de Pearson e ANOVA para medidas repetidas, seguido do teste post hoc de Tukey (p < 0,05). RESULTADOS: A idade média dos pacientes foi de 20 ± 4 anos, e a CVF média foi de 29 ± 12 por cento. A média de PFT basal, com compressão torácica, com empilhamento de ar e com o uso da técnica combinada foi 171 ± 67, 231 ± 81, 225 ± 80, e 292 ±86 L/min, respectivamente. Os resultados com o uso da técnica combinada foram maiores que aqueles com o uso das duas técnicas separadamente [F(3,69) = 67,07; p < 0,001]. CONCLUSÕES: As técnicas de compressão torácica e de empilhamento de ar foram eficientes para aumentar o PFT. No entanto, a combinação dessas manobras teve um efeito aditivo significativo (p < 0,0001).

OBJECTIVE: To evaluate cough efficiency using two manually-assisted cough techniques. METHODS: We selected 28 patients with Duchenne muscular dystrophy. The patients were receiving noninvasive nocturnal ventilatory support and presented FVC values < 60 percent of predicted. Peak cough flow (PCF) was measured, with the patient seated, at four time points: at baseline, during a spontaneous maximal expiratory effort (MEE); during an MEE while receiving chest compression; during an MEE after air stacking with a manual resuscitation bag; and during an MEE with air stacking and compression (combined technique). The last three measurements were conducted in random order. The results were compared using Pearson's correlation test and ANOVA with repeated measures, followed by Tukey's post-hoc test (p < 0.05). RESULTS: The mean age of the patients was 20 ± 4 years, and the mean FVC was 29 ± 12 percent. Mean PCF at baseline, with chest compression, after air stacking and with the use of the combined technique was 171 ± 67, 231 ± 81, 225 ± 80, and 292 ± 86 L/min, respectively. The results obtained with the use of the combined technique were significantly better than were those obtained with the use of either technique alone (F[3.69] = 67.07; p < 0.001). CONCLUSIONS: Both chest compression and air stacking techniques were efficient in increasing PCF. However, the combination of these two techniques had a significant additional effect (p < 0.0001).