BACKGROUND Electronic cigarettes(ECs)have been promoted as alternatives to traditional cigarettes.To investigate ECs’effects on respiratory system,especially in patients with respiratory diseases.METHODS We randomly ...BACKGROUND Electronic cigarettes(ECs)have been promoted as alternatives to traditional cigarettes.To investigate ECs’effects on respiratory system,especially in patients with respiratory diseases.METHODS We randomly selected 25 smokers with stable moderate asthma and matched them with 25 healthy smokers.All were subjucted to pulmonary function tests(PFTs),impulse oscillometry(IOS),fraction exhaled Nitric Oxide(FeNO),exhaled breathe condensate(EBC)and biomarker measurements before and after vaping one nicotinecontaining EC.RESULTS The increase in FeNO 30 minutes after EC,reflecting airway inflammation,significantly correlated with increase of residual volume(RV),total lung capacity,respiratory impedance at 5 Hz(Z5Hz)and respiratory resistance at 5 and 20 Hz(R5Hz and R20Hz).No significant correlations were found between EBC biomarkers'changes and respiratory mechanics.CONCLUSION This is the first study demonstrating that the changes in airway inflammation caused by EC have direct effects in respiratory mechanics of asthmatic patients.展开更多
Background:The aim of this review is to summarize the current evidence regarding small airway disease in asthma,focusing on recent advances in small airway pathophysiology,assessment and therapeutic implications.Metho...Background:The aim of this review is to summarize the current evidence regarding small airway disease in asthma,focusing on recent advances in small airway pathophysiology,assessment and therapeutic implications.Methods:A search in Medline was performed,using the keywords“small airways”,“asthma”,“oscillometry”,“nitrogen washout”and“imaging”.Our review was based on studies from adult asthmatic patients,although evidence from pediatric populations is also discussed.Results:In asthma,inflammation in small airways,increased mucus production and airway wall remodelling are the main pathogenetic mechanisms of small airway disease.Small airway dysfunction is a key component of asthma pathophysiology,leading to increased small airway resistance and airway closure,with subsequent ventilation inhomogeneities,hyperresponsiveness and airflow limitation.Classic tests of lung function,such as spirometry and body plethysmography are insensitive to detect small airway disease,providing only indirect measurements.As discussed in our review,both functional and imaging techniques that are more specific for small airways,such as oscillometry and the multiple breath nitrogen washout have delineated the role of small airways in asthma.Small airways disease is prevalent across all asthma disease stages and especially in severe disease,correlating with important clinical outcomes,such as asthma control and exacerbation frequency.Moreover,markers of small airways dysfunction have been used to guide asthma treatment and monitor response to therapy.Conclusions:Assessment of small airway disease provides unique information for asthma diagnosis and monitor-ing,with potential therapeutic implications.展开更多
The change of measurements of impulse oscillometry (105) in obstructive sleep apnea syn- drome (OSAS) patients and its mechanism were observed. The respiratory impedance was measured by using IOS technique and polyso...The change of measurements of impulse oscillometry (105) in obstructive sleep apnea syn- drome (OSAS) patients and its mechanism were observed. The respiratory impedance was measured by using IOS technique and polysomnography (PSG) was monitored synchronously in 36 OSAS pa- tients,14 patients with chronic obstructive pulmonary disease (COPD) and 12 normal controls. Re- sults showed that R20 in OSAS group was significantly higher than in COPD group and control group (P<0.01). R5-R20 in OSAS group was lower than that in COPD group, but significantly higher than that in control group(P<0. 01). The levels of R20 and R5-R20 were positively correlated with severity degree of the disease. In addition, apnea-hyponea index (AHI) was positively correlated with R5 and R20 with the correlation index (r)being 0. 66 and 0. 86 respectively. The lowest SO2 was negatively correlated with R5 and R5-R20, with r being-0. 66 and- 0. 79 respectively. The mean SO2 was negatively correlated with R5 and R5-R20 with r being-0. 81 and-0. 69 respectively. IOS technique could be used as a valuable tool for assessing the degree of upper airway obstruction in the patients with OSAS, and could help to explore its pathological mechanism.展开更多
In the most common version of an oscillometric blood pressure monitor, the output from the pressure transducer, Y(t), is split into two parts, and used for separate determinations of the pressure inside the pneumatic ...In the most common version of an oscillometric blood pressure monitor, the output from the pressure transducer, Y(t), is split into two parts, and used for separate determinations of the pressure inside the pneumatic cuff and its fluc-tuating part;the latter is derived by sending Y(t) to a high-pass filter (HPF) and amplifying the fil-tered part to obtain the oscillometric signal O(t). Using a typical HPF-amplifier combination, we show that if p(t), the pulsatile part of the cuff pressure, is defined to be a train of positive-going pulses, O(t) turns out to be rather close but not identical to dp/dt, and to demonstrate that one can easily retrieve p(t) from a record of O(t). This means that, with a small modification, the instrument can provide both p(t) and dp/dt;the practical advantages of this demonstration are pointed out.展开更多
A noninvasive method for monitoring blood pressure, based on the principles established by Riva-Rocci and Korotkoff (K), is described;it furnishes, after a single compression-deflation cycle of the arm-encircling cuff...A noninvasive method for monitoring blood pressure, based on the principles established by Riva-Rocci and Korotkoff (K), is described;it furnishes, after a single compression-deflation cycle of the arm-encircling cuff, values of sys-tolic and diastolic blood pressures as well as the contours of the brachial arterial pulse and the corresponding volume pulse. K-sounds are detected by a single microphone situated in the cubital fossa, and the time-varying cuff pressure P(t) is read by a piezoresistive pressure sensor. The behavior of P(t) during deflation is resolved into two parts, P(t)=p(t)+b(t);p is a train of posi-tive going pulses (arising from arterial pulsa-tions), whereas b is a slowly changing baseline. Noise pulses in the microphone output are re-jected by using the observation that the first few K-sounds are emitted when p is close to a maxi-mum, and the last few when dp/dt is close to a maximum. The performance of the instrument is illustrated by showing how it copes with ambi-ent noise and involuntary manual perturbations of P, and by presenting contours of various pulses.展开更多
Objective: To observe the relationship of deep slow respiratory pattern and respiratory impedance(RI) in patients with chronic obstructive pulmonary disease (COPD). Methods: RI under normal respiration and during deep...Objective: To observe the relationship of deep slow respiratory pattern and respiratory impedance(RI) in patients with chronic obstructive pulmonary disease (COPD). Methods: RI under normal respiration and during deep slow respira tion was measured one after the other with impulse oscillometry for 8 patients with COPD and for 9 healthy volunteers as control. Results: When r espiration was changed from normal pattern to the deep slow pattern, the tida l volume increased and respiratory frequency significantly decreased in both gro ups , the total respiratory impedance (Z respir) showed a decreasing trend in COPD group, but with no obvious change in the control group. No chang e in the resonant frequency (fres) was found in both groups, and the respiratory viscous resistance obviously decreased in the COPD group(R5: P =0.0168 ; R20: P =0.0498; R5—R20: P =0.0388),though in the control group it was unchanged. Conclusion: IOS detection could reflect the response he terogeneity of different compartments of respiratory system during tidal breathi ng. During deep slow respiration, the viscous resistance in both central airw ay and peripheral airway was decreased in patients with COPD. RI measurement by impulse oscillometry may be a convenient pathophysiological method for studying the application of breathing exercise in patients with COPD.展开更多
Background: CHF (Congestive Heart Failure) is one of the most important causes of mortality and morbidity in the world. Diuretics such as spironolactone can decrease pulmonary congestion and reduce the amount of fibro...Background: CHF (Congestive Heart Failure) is one of the most important causes of mortality and morbidity in the world. Diuretics such as spironolactone can decrease pulmonary congestion and reduce the amount of fibrosis in CHF patients. The goal was to assess whether spironolactone can decrease air way resistance and can we follow up the effect of diuretic therapy in patients of heart failure quantitatively by means of impulse oscillometry. Methods: It was clinical trial which performed in Ahvaz teaching hospital. 24 patients with congestive heart failure (CHF) which was classified as functional class II-IV and had EF Result: The age of patient was 61 ± 10 and the age of control was 57 ± 7 years old. The data of oscillometry before and after spironolactone were X5 (−0.14 ± 0.05 vs −0.14 ± 0.05, P: 0.93), R5 (0.39 ± 0.21 vs 0.39 ± 0.15, P: 0.35), X20 (−0.04 ± 0.06 vs −0.06 ± 0.06, P: 0.37), R20 (0.04 ± 0.03 vs 0.06 ± 0.06, P: 0.37), Zrs (0.39 ± 0.21 vs 0.39 ± 0.15, P: 0.35). Conclusion: There was a trend toward reduction of peripheral airway resistances in CHF patients than controls with use of 1 month of spironolactone. Although there was not significant change in the number of X5, R5, X20, R20 occurred the trend toward reduction of number triggers the point that oscillometry can be used for quantitative follow up of CHF patients.展开更多
Superior vena cava syndrome (SVCS) patients sometimes show signs of obstructive sleep apnea (OSA). However, the mechanism causing hypoxia during sleep in SVCS patients is still uncertain. The aim of this study was to ...Superior vena cava syndrome (SVCS) patients sometimes show signs of obstructive sleep apnea (OSA). However, the mechanism causing hypoxia during sleep in SVCS patients is still uncertain. The aim of this study was to elucidate 1) the changes in central and peripheral respiratory resistance with SVCS, and 2) interpret the mechanism underlying the development of hypoxia during sleep in patients with SVCS related to OSA. Ten SVCS patients related to a neoplasm were recruited for this study. The degree of apnea hypopnea index (AHI) for OSA was evaluated by portable diagnosing device before and after SVCS treatment. We also analyzed the airway resistance and reactance quantitatively in the supine position by Master Screen impulse oscillometry system (MS-IOS?). After SVCS treatment, mean values of AHI were significantly decreased from 30.9 to 16.9 (/hour) (p = 0.001). Central respiratory resistance (R20) also decreased significantly from 0.40 to 0.33 kPa/L/s (p = 0.025) in the supine position. In contrast, peripheral respiratory resistance (R5-R20) and distal capacitive reactance (X5) did not change significantly. It is thought that the exacerbation of OSA due to SVCS is caused by increasing upper airway resistance related to reversible edema of the upper airway mucous or tissue. In contrast, SVCS may not cause peripheral respiratory tract and lung parenchyma edema.展开更多
文摘BACKGROUND Electronic cigarettes(ECs)have been promoted as alternatives to traditional cigarettes.To investigate ECs’effects on respiratory system,especially in patients with respiratory diseases.METHODS We randomly selected 25 smokers with stable moderate asthma and matched them with 25 healthy smokers.All were subjucted to pulmonary function tests(PFTs),impulse oscillometry(IOS),fraction exhaled Nitric Oxide(FeNO),exhaled breathe condensate(EBC)and biomarker measurements before and after vaping one nicotinecontaining EC.RESULTS The increase in FeNO 30 minutes after EC,reflecting airway inflammation,significantly correlated with increase of residual volume(RV),total lung capacity,respiratory impedance at 5 Hz(Z5Hz)and respiratory resistance at 5 and 20 Hz(R5Hz and R20Hz).No significant correlations were found between EBC biomarkers'changes and respiratory mechanics.CONCLUSION This is the first study demonstrating that the changes in airway inflammation caused by EC have direct effects in respiratory mechanics of asthmatic patients.
基金DT is a recipient of a Long-Term Research Fellowship from the Eu-ropean Respiratory Society.
文摘Background:The aim of this review is to summarize the current evidence regarding small airway disease in asthma,focusing on recent advances in small airway pathophysiology,assessment and therapeutic implications.Methods:A search in Medline was performed,using the keywords“small airways”,“asthma”,“oscillometry”,“nitrogen washout”and“imaging”.Our review was based on studies from adult asthmatic patients,although evidence from pediatric populations is also discussed.Results:In asthma,inflammation in small airways,increased mucus production and airway wall remodelling are the main pathogenetic mechanisms of small airway disease.Small airway dysfunction is a key component of asthma pathophysiology,leading to increased small airway resistance and airway closure,with subsequent ventilation inhomogeneities,hyperresponsiveness and airflow limitation.Classic tests of lung function,such as spirometry and body plethysmography are insensitive to detect small airway disease,providing only indirect measurements.As discussed in our review,both functional and imaging techniques that are more specific for small airways,such as oscillometry and the multiple breath nitrogen washout have delineated the role of small airways in asthma.Small airways disease is prevalent across all asthma disease stages and especially in severe disease,correlating with important clinical outcomes,such as asthma control and exacerbation frequency.Moreover,markers of small airways dysfunction have been used to guide asthma treatment and monitor response to therapy.Conclusions:Assessment of small airway disease provides unique information for asthma diagnosis and monitor-ing,with potential therapeutic implications.
文摘The change of measurements of impulse oscillometry (105) in obstructive sleep apnea syn- drome (OSAS) patients and its mechanism were observed. The respiratory impedance was measured by using IOS technique and polysomnography (PSG) was monitored synchronously in 36 OSAS pa- tients,14 patients with chronic obstructive pulmonary disease (COPD) and 12 normal controls. Re- sults showed that R20 in OSAS group was significantly higher than in COPD group and control group (P<0.01). R5-R20 in OSAS group was lower than that in COPD group, but significantly higher than that in control group(P<0. 01). The levels of R20 and R5-R20 were positively correlated with severity degree of the disease. In addition, apnea-hyponea index (AHI) was positively correlated with R5 and R20 with the correlation index (r)being 0. 66 and 0. 86 respectively. The lowest SO2 was negatively correlated with R5 and R5-R20, with r being-0. 66 and- 0. 79 respectively. The mean SO2 was negatively correlated with R5 and R5-R20 with r being-0. 81 and-0. 69 respectively. IOS technique could be used as a valuable tool for assessing the degree of upper airway obstruction in the patients with OSAS, and could help to explore its pathological mechanism.
文摘In the most common version of an oscillometric blood pressure monitor, the output from the pressure transducer, Y(t), is split into two parts, and used for separate determinations of the pressure inside the pneumatic cuff and its fluc-tuating part;the latter is derived by sending Y(t) to a high-pass filter (HPF) and amplifying the fil-tered part to obtain the oscillometric signal O(t). Using a typical HPF-amplifier combination, we show that if p(t), the pulsatile part of the cuff pressure, is defined to be a train of positive-going pulses, O(t) turns out to be rather close but not identical to dp/dt, and to demonstrate that one can easily retrieve p(t) from a record of O(t). This means that, with a small modification, the instrument can provide both p(t) and dp/dt;the practical advantages of this demonstration are pointed out.
文摘A noninvasive method for monitoring blood pressure, based on the principles established by Riva-Rocci and Korotkoff (K), is described;it furnishes, after a single compression-deflation cycle of the arm-encircling cuff, values of sys-tolic and diastolic blood pressures as well as the contours of the brachial arterial pulse and the corresponding volume pulse. K-sounds are detected by a single microphone situated in the cubital fossa, and the time-varying cuff pressure P(t) is read by a piezoresistive pressure sensor. The behavior of P(t) during deflation is resolved into two parts, P(t)=p(t)+b(t);p is a train of posi-tive going pulses (arising from arterial pulsa-tions), whereas b is a slowly changing baseline. Noise pulses in the microphone output are re-jected by using the observation that the first few K-sounds are emitted when p is close to a maxi-mum, and the last few when dp/dt is close to a maximum. The performance of the instrument is illustrated by showing how it copes with ambi-ent noise and involuntary manual perturbations of P, and by presenting contours of various pulses.
文摘Objective: To observe the relationship of deep slow respiratory pattern and respiratory impedance(RI) in patients with chronic obstructive pulmonary disease (COPD). Methods: RI under normal respiration and during deep slow respira tion was measured one after the other with impulse oscillometry for 8 patients with COPD and for 9 healthy volunteers as control. Results: When r espiration was changed from normal pattern to the deep slow pattern, the tida l volume increased and respiratory frequency significantly decreased in both gro ups , the total respiratory impedance (Z respir) showed a decreasing trend in COPD group, but with no obvious change in the control group. No chang e in the resonant frequency (fres) was found in both groups, and the respiratory viscous resistance obviously decreased in the COPD group(R5: P =0.0168 ; R20: P =0.0498; R5—R20: P =0.0388),though in the control group it was unchanged. Conclusion: IOS detection could reflect the response he terogeneity of different compartments of respiratory system during tidal breathi ng. During deep slow respiration, the viscous resistance in both central airw ay and peripheral airway was decreased in patients with COPD. RI measurement by impulse oscillometry may be a convenient pathophysiological method for studying the application of breathing exercise in patients with COPD.
文摘Background: CHF (Congestive Heart Failure) is one of the most important causes of mortality and morbidity in the world. Diuretics such as spironolactone can decrease pulmonary congestion and reduce the amount of fibrosis in CHF patients. The goal was to assess whether spironolactone can decrease air way resistance and can we follow up the effect of diuretic therapy in patients of heart failure quantitatively by means of impulse oscillometry. Methods: It was clinical trial which performed in Ahvaz teaching hospital. 24 patients with congestive heart failure (CHF) which was classified as functional class II-IV and had EF Result: The age of patient was 61 ± 10 and the age of control was 57 ± 7 years old. The data of oscillometry before and after spironolactone were X5 (−0.14 ± 0.05 vs −0.14 ± 0.05, P: 0.93), R5 (0.39 ± 0.21 vs 0.39 ± 0.15, P: 0.35), X20 (−0.04 ± 0.06 vs −0.06 ± 0.06, P: 0.37), R20 (0.04 ± 0.03 vs 0.06 ± 0.06, P: 0.37), Zrs (0.39 ± 0.21 vs 0.39 ± 0.15, P: 0.35). Conclusion: There was a trend toward reduction of peripheral airway resistances in CHF patients than controls with use of 1 month of spironolactone. Although there was not significant change in the number of X5, R5, X20, R20 occurred the trend toward reduction of number triggers the point that oscillometry can be used for quantitative follow up of CHF patients.
文摘Superior vena cava syndrome (SVCS) patients sometimes show signs of obstructive sleep apnea (OSA). However, the mechanism causing hypoxia during sleep in SVCS patients is still uncertain. The aim of this study was to elucidate 1) the changes in central and peripheral respiratory resistance with SVCS, and 2) interpret the mechanism underlying the development of hypoxia during sleep in patients with SVCS related to OSA. Ten SVCS patients related to a neoplasm were recruited for this study. The degree of apnea hypopnea index (AHI) for OSA was evaluated by portable diagnosing device before and after SVCS treatment. We also analyzed the airway resistance and reactance quantitatively in the supine position by Master Screen impulse oscillometry system (MS-IOS?). After SVCS treatment, mean values of AHI were significantly decreased from 30.9 to 16.9 (/hour) (p = 0.001). Central respiratory resistance (R20) also decreased significantly from 0.40 to 0.33 kPa/L/s (p = 0.025) in the supine position. In contrast, peripheral respiratory resistance (R5-R20) and distal capacitive reactance (X5) did not change significantly. It is thought that the exacerbation of OSA due to SVCS is caused by increasing upper airway resistance related to reversible edema of the upper airway mucous or tissue. In contrast, SVCS may not cause peripheral respiratory tract and lung parenchyma edema.
