The Diagnosis Value and Its Implication of Impulse Oscillometry in Obstructive Sleep Apnea Syndrome Patients

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.

Is there a correlation between the changes in airway inflammation and the changes in respiratory mechanics after vaping in patients with asthma?

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.

Assessment of Respiratory lmpedance During Deep Slow Breathing with lmpulse Oscillometry in Patients with Chronic Obstructive Pulmonary Disease

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.

The applicable value of respiratory impedance for the stage 0 of chronic obstructive pulmonary disease

Objective ：To evaluate the applicable value of respiratory impedance for the stage 0 of chronic obstructive pulmonary disease （COPD）. Methods：Respiratory impedance was measured by impulse oscillometry （lOS） in 41 cases at stage 0 of COPD （NHLBI/WHO, 2001 Standard） and their conventional pulmonary function values were compared with 42 healthy subjects. Both groups had no significant deviation in age, stature and avoirdupois, etc. Master-Screen pulmonary function test system （Jaeger Co, Germany） were used to determine IOS parameters including viscous resistance of 5Hz, 20 Hz and 35Hz （R5, R20, R35）, reactance of 5Hz, 35 Hz （X3, X35）, resonant frequency （Fres） ,total respiratory impedance （Zrs） and routine pulmonary function values including forced expiratory volume in one second to predicted value （FEV1 % ）, forced expiratory volume in one second to forced vital capacity ratio（ FEV1/ FVC% ）, maximal mid expiratory flow （MMEF%）,V23% and V50%. Results：Both groups had no significant deviation in FEV1%, FEV1/FVC% and X35（P〉0.05）. It was increased significantly in viscous resistance of 5Hz, 20 Hz and 35Hz （R5, R20, R35） in COPD group than that in healthy group （P〈0.01）. So were Fres and Zrs （P〈0.01）. MMEF%,V25%,V50% and reactance of 5Hz （X5） in COPD group were marked lower than that in healthy group （P〈0.01）. The sensitivity of MMEF%, V25%,V50% was higher than others, but its specificity was lower. In parameters of IOS, Fres was the most sensitive index for diagnosis of the small airway function and its specificity was higher than that of MMEF%, V25% ,V50%. Conclusion：In the risk case at the stage 0 of COPD, MMEF%, V25% and V50% could be decreased, but Fres, R5 ,R5-20 could be increased in spite of FEV1% and FEV1/FVC% in normal range.

氣道阻力與常規肺功能測試在慢性阻塞性肺病診斷中的對比研究

目的探討氣道阻力在慢性阻塞性肺病(COPD)診斷中的臨床價值。方法對108例COPD患者及22例正常成人應用脈沖振蕩肺功能測定氣道阻力,並與常規肺功能進行比較,分析它們對COPD的診斷價值。結果COPD各組及對照組間常規肺功能指標FEV1、FEV1/FVC%、FEV1/Pre%、PEF、PEF/Pre%均有統計學意義;COPD組Z5、R5、(R5-R20)、RF、Rp、R5(A/P%)、Z5(A/P%)明顯高於對照組,且隨COPD嚴重程度增加而升高;X5、X20 COPD組顯著低於對照組,且隨COPD嚴重程度增加而降低;Z5、R5、(R5-R20)、RF、Rp、R5(A/P%)、Z5(A/P)%分別與FEV1、FEV1/FVC%、FEV1/Pre%、PEF、PEF/Pre%呈顯著負相關,與X5、X20呈顯著正相關,其中RF的相關性最爲密切;IOS各指標ROC曲線分析顯示,R5(A1/P%)正常值取值爲136時,約登指數最高;Z5(A1/P%)正常值取值爲100時,約登指數最高;RF正常值取值爲18.23時,X5正常值取值爲-0.24時,X20正常值取值爲0.005時,各約登指數最高。結論脈沖振蕩肺功能對COPD具有診斷價值,其指標與病情嚴重程度相關;與常規肺功能指標有顯著相關性。但其預計值方程式及正常值範圍值得進一步研究。