容积二氧化碳图及其指标诊断慢性阻塞性肺疾病患者换气功能的评价

目的 评价容积二氧化碳图(VCap)及其指标诊断慢性阻塞性肺疾病(COPD)患者换气功能障碍的临床应用价值.方法 比较分析COPD组92例与对照组48例VCap及其11项指标[Bohr测定法死腔(VD-B)、呼气末最大CO2浓度(CO2max)、呼出气CO2浓度为25%～50%时的容量(Vm25-50)、呼出气CO2浓度为50%～75%时的容量(Vm50 75)、潮气量(VT)、VD-B/VT、Vm25-50/VT、Vm50-75/VT、Ⅱ期斜率(dC/dV2)、Ⅲ期斜率(dC/dV3)和Ⅲ期斜率/Ⅱ期斜率× 100(SR23)]的差别.结果 COPD组与对照组CO2 max、Vm50-75、VT、VD-B/VT、Vm25 50/VT、Vm50-75/VT、dC/dV2、dC/dV3和SR23等9项指标差异有统计学意义(P＜0.05).在COPD组中,Ⅱ级与Ⅲ级的VD-B/VT、Vm25-50/VT、dC/dV3和SR23等4项指标差异有统计学意义(P＜0.05);Ⅱ级与Ⅳ级的dC/dV2、dC/dV3和SR23等3项指标差异有统计学意义(P＜0.05);Ⅲ级与Ⅳ级dC/dV3和SR23等2项指标差异有统计学意义(P＜0.05).结论 COPD组VCap曲线形态有异常改变,dC/dV3和SR23可作为最佳诊断指标.VCap检测技术具有无创性和价廉等优点,是诊断COPD换气功能状况的好方法.

Abstract：

Objective To evaluate on volumetric capnography ( VCap) change of patients with chronic obstructive pulmonary diseases (COPD), diagnosing their dysfunction of ventilation. Methods Compard the differences between the 92 patients of COPD group and 48 healthly people of control group on VCap and its indices ( VD-B, CO2max, Vm25-50, Vm50-57 , VT, VD-B/VT, Vm25-50/VT, Vm50-57/VT,dC/dV2 ,dC/dV3 and SR23). Results There were significant differences ( P ＜0. 05) between COPD group and control group on VCap and its indices (CO2max, Vm50 75 ,VT,VD-B/VT,Vm25-50/VT, Vm50-57/VT,dC/dV2 ,dC/dV3 and SR23), between COPDⅡ and COPD Ⅲ on VCap indices (VD-B/VT, Vm25 50/VT,dC/dV3 and SR23), between COPD Ⅱ and COPDIV on VCap indices (dC/dV2 ,dC/dV3 and SR23),between COPDⅢ and COPDIV on dC/dV3 and SR23. Conclusions The shape of VCap curve of the COPD group were significant different from the control group. For diagnosing dysfunction of ventilation COPD patient, the dC/dV3 and SR23 were the best indices, and the VD-B/VT, Vm25-50/VT and Vm50-75/VT were more significant than the VD-B,CO2 max, Vm25-50 and Vm50-75.     

慢性阻塞性肺疾病容积二氧化碳图的改变

二氧化碳图是无创监测呼出气CO2水平的方法,其中容积二氧化碳图(VCap)以呼出气CO2分压或浓度为纵轴,呼出气容积为横轴(图1),仅体现呼气过程中CO2水平随呼出气体积增加的变化,其参数分析及解释较为复杂,但可以提供较多的信息.为探讨VCap参数在COPD诊治方面的意义,我们对66例COPD患者进行了肺通气功能、肺容量指标和VCap测定.     

气道高反应性在COPD和哮喘的比较

目的探讨慢性阻塞性肺疾病(chronic obstructive pulmonary diseases,COPD)和支气管哮喘(简称哮喘)患者在组胺支气管激发试验中气道高反应性(airwayhyperresponsiveness,AHR)的不同。方法将我院2008～2010年间诊断为COPD和哮喘的并经随访一年处于稳定期的患者共80例,其中COPD组39例,哮喘组41例,均行支气管组胺激发试验,观察FEF25%～75%/FVC(肺活量为25%～75%时最大呼气流量与用力肺活量的比值)在两组患者的变化。结果 COPD组FEF25%～75%和FEF25%～75%/FVC均明显低于哮喘组(P值均<0.01);以激发试验阳性的两组患者为对象分别进行简单相关分析,在COPD组和哮喘组中FEF25%～75%/FVC与Log10DRS呈负相关(r分别为-0.510和-0.466,P<0.05),与PD20FEV1呈正相关(r分别为0.518和0.487,P<0.05),说明相对于肺容积而言,气道容积越小,气道收缩性越强,反应性越高。随后在以气道收缩性指标Log10DRS为因变量,以年龄、体表面积、FEV1%及FEF25%～75%/FVC为自变量进行线性回归分析,在COPD组FEV1%对Log10DRS较FEF25%～75%/FVC影响大(P<0.05),而哮喘组不存在这情况。结论在COPD中AHR患者并不少见,其发生机制与哮喘是不同的。     

FeNO、IgE在COPD和ACOS鉴别诊断中的价值分析

目的探讨呼出气一氧化氮(FeNO)、血清总IgE在诊断气管哮喘-慢性阻塞性肺疾病(哮喘-慢阻肺)重叠综合征(ACOS)与慢性阻塞性肺疾病(COPD)的价值。方法回顾性分析我院2015年8月至2017年9月收治的55例ACOS患者、66例COPD患者及32例哮喘患者的临床资料。比较三组患者的肺功能、呼出气一氧化氮(FeNO)和血清总免疫球蛋白E(IgE)表达水平。分析FeNO与血清总IgE在鉴别诊断COPD和ACOS中的价值及两者与ACOS疾病严重程度的关系。结果 ACOS组、COPD组和哮喘组FEV_1占预计值%、FEV_1/FVC、FeNO和血清总IgE水平比较,差异均具有统计学意义(P均0. 05),且两两比较,差异显著(P均0. 05)。FeNO、血清总IgE诊断ACOS均具有较高的诊断价值。ACOS患者FeNO与IgE均成正相关,与FEV_1占预计值%和FEV_1/FVC均无明显相关性(P 0. 05)。FeNO与IgE随着ACOS患者严重程度的加重,其水平呈升高的趋势,四组间两两比较差异有统计学意义(P 0. 05)。结论 FeNO、血清总IgE在ACOS和COPD患者中差异化表达,在ACOS诊断中具有较高价值并且与ACOS严重程度存在关系。     

老年哮喘-慢性阻塞性肺疾病重叠综合征患者呼出气一氧化氮及过敏原检测的临床价值

目的探讨呼出气一氧化氮(FeNO)和过敏原检测在老年哮喘-慢性阻塞性肺疾病(COPD)重叠综合征(ACOS)患者中诊疗价值。方法老年ACOS40例、哮喘35例、COPD40例及非呼吸系统疾病患者40例均进行FeNO、过敏原、肺通气功能检测,分析4组FeNO、过敏原阳性率、第1秒用力呼气量(FEV1)/pred%、FEV1/肺活量(FVC)的差异。结果老年ACOS组的FeNO值明显高于COPD组及非呼吸系统疾病组(P<0.05),低于哮喘组但两组差异无统计学意义(P>0.05)。老年ACOS组过敏原阳性率显著高于COPD组和非呼吸系统疾病组,差异有统计学意义(P<0.05),低于哮喘组但两组比较差异无统计学意义(P>0.05)。老年ACOS组肺通气功能FEV1/pred%、FEV1/FVC明显低于非呼吸系统疾病组和哮喘组(P<0.05),高于COPD组,但差异无统计学意义(P>0.05)。结论联合FeNO与过敏原、肺通气功能检测有助于ACOS的诊断及ACOS与其他慢性阻塞性气道疾病的鉴别诊断;老年ACOS患者FeNO及过敏原阳性率明显增高。     

气道高反应性在COPD和哮喘的比较

目的 探讨慢性阻塞性肺疾病(chronic obstructive pulmonary diseases,COPD)和支气管哮喘(简称哮喘)患者在组胺支气管激发试验中气道高反应性(airway hyperresponsiveness,AHR)的不同.方法 将我院2008～2010年间诊断为COPD和哮喘的并经随访一年处于稳定期的患者共80例,其中COPD组39例,哮喘组41例,均行支气管组胺激发试验,观察FEF25％～75％/FVC(肺活量为25％～75％时最大呼气流量与用力肺活量的比值)在两组患者的变化.结果 COPD组FEF25％～75％和FEF25％～75 ％/FVC均明显低于哮喘组(P值均＜0.01);以激发试验阳性的两组患者为对象分别进行简单相关分析,在COPD组和哮喘组中FEF25％～75％/FVC与Log10DRS呈负相关(r分别为-0.510和-0.466,P＜0.05),与PD20FEV1呈正相关(r分别为0.518和0.487,P＜0.05),说明相对于肺容积而言,气道容积越小,气道收缩性越强,反应性越高.随后在以气道收缩性指标Log10DRS为因变量,以年龄、体表面积、FEV1％及FEF25％～75 ％/FVC为自变量进行线性回归分析,在COPD组FEV1％对Log10DRS较FEF25％～75％/FVC影响大(P＜0.05),而哮喘组不存在这情况.结论 在COPD中AHR患者并不少见,其发生机制与哮喘是不同的.     

支气管哮喘患者呼出气一氧化氮、肺功能、ACQ7评分之间的相关性研究

目的 探讨呼出气一氧化氮(FeNO)、肺通气功能及支气管哮喘(简称哮喘)控制水平的相关关系,寻找适用于哮喘患者的气道炎症监测及管理的方法.方法 按GINA 2008标准入选我院门诊2010年3月至2011年6月就诊65例确诊为哮喘的患者 进行FeNO测定 同时测定肺功能 记录第1秒用力呼气容积(FEV1)、第1秒用力呼...     

死腔测定在支气管哮喘中应用价值的研究

目的 探讨容积二氧化碳图(volumetric capnography,VCap)技术死腔测定在支气管哮喘(简称哮喘)中的应用价值及临床意义.方法 对52例急性发作期哮喘患者及35名健康志愿者的常规肺功能指标及Langley 死腔(VDL)、Fowler死腔(VDF)、Wolff死腔(VDW)进行测定分析.结果 本研究显示:哮喘组中VDL、VDF及VDW均较对照组显著减小(P<0.01,0.01,0.01).相关分析显示:VDL、VDF和VDW分别与FEV1占预计值%、FEV1/FVC%、PEF占预计值%、FEF25占预计值%、FEF50占预计值%、FEF75占预计值%、MMEF占预计值%呈负相关(P<0.05),与RV占预计值%、TLC占预计值%、RV/TLC%呈正相关(P<0.05).结论 VCap死腔测定患者易于配合,对哮喘的辅助诊断及进一步了解其病理生理改变具有一定的临床价值和意义.     

呼出气一氧化氮在间质性肺疾病诊疗中的应用

间质性肺疾病(ILD)作为一组以急慢性炎症导致肺间质慢性炎症及进行性纤维化的疾病,其发病机制及诊治并未完全清楚。呼出气一氧化氮(eNO)作为一种气道炎症分子标志物已成功应用于哮喘等气道炎症性疾病的诊疗中,但其对于 ILD 的诊治价值尚未明确。本文通过学习 eNO对 ILD 研究的相关文献探讨 eNO 对 ILD 诊治的临床价值。     

死腔测定在支气管哮喘中应用价值的研究

目的 探讨容积二氧化碳图(volumetric capnography,VCap)技术死腔测定在支气管哮喘(简称哮喘)中的应用价值及临床意义.方法 对52例急性发作期哮喘患者及35名健康志愿者的常规肺功能指标及Langley死腔(VDL)、Fowler死腔(VDF)、Wolff死腔(VDW)进行测定分析.结果 本研究显示:哮喘组中VDL、VDF及VDW均较对照组显著减小(P<0.01,0.01,0.01).相关分析显示:VDL、VDF和VDW分别与FEV1占预计值%、FEV1/FVC%、PEF占预计值%、FEF25占预计值%、FEF50占预计值%、FEF75占预计值%、MMEF占预计值%呈负相关(P<0.05),与RV占预计值%、TLC占预计值%、Rv/TLC%呈正相关(P<0.05).结论 VCap死腔测定患者易于配合,对哮喘的辅助诊断及进一步了解其病理生理改变具有一定的临床价值和意义.     

The Ability of Volumetric Capnography to Distinguish between Chronic Obstructive Pulmonary Disease Patients and Normal Subjects

Purpose

The aim of our study was to evaluate volumetric capnography (VCap) in the differentiation between chronic obstructive pulmonary disease (COPD) patients and normal subjects.

Patients and Methods

Thirty-nine healthy male volunteers and 60 male COPD patients were enrolled. Regression equations between VCap indices and age, weight, height, and tidal volume in healthy volunteers were established by stepwise regression analysis. Predicted normal values of VCap indices in COPD patients were calculated. A paired t test was used to compare the difference between observed and predicted values for VCap indices in COPD patients. Receiver operating characteristic (ROC) curve analysis was used to evaluate the power of each VCap index alone in differentiating COPD patients and normal subjects. The power of the combination of VCap indices was assessed by discriminant analysis.

Results

All regression equations were significant (P < 0.01) as were the differences between the observed and predicted normal VCap indices in COPD patients (P < 0.001). ROC curve analysis showed that the volume between 25 and 50 % of F CO2et (Vm25-50), slope of Phase II (dC2/dV), and slope of Phase III (dC3/dV) were valuable predictors. Nearly all (90.9 %) subjects were correctly classified by discriminant analysis.

Conclusion

Vm25-50, dC2/dV, or dC3/dV alone are valuable for differentiating COPD patients and normal subjects, but more powerful are the combinations of Vm25-50, dC2/dV, and dC3/dV, the ratio of dC2/dV to dC3/dV (SR23), dead space according to the Bohr method (VDB), and dead space according to the Wolff and Brunner methods (PIE).     

Exhaled nitric oxide in chronic obstructive pulmonary disease: relationship to pulmonary function.

The following study was undertaken in order to determine how exhaled nitric oxide (eNO) levels in former smokers with chronic obstructive pulmonary disease (COPD) compared to eNO levels in patients with asthma and in healthy nonsmoking volunteers. The study also aimed to determine any relationship between eNO levels in COPD and: 1) conventional measures of lung function; and 2) inhaled corticosteroid (ICS) use. In former smokers with COPD, nonsmokers with asthma and volunteers, eNO levels, spirometry, lung volumes, carbon monoxide diffusion capacity of the lung (DL,CO) and resting oxygen saturation (Sa,O2) were measured. Median eNO was significantly higher among patients with COPD than among healthy volunteers (p = 0.003) but lower than among patients with asthma (p < 0.01). There was no significant difference in eNO levels between COPD patients using ICS and those not using ICS. By contrast, eNO was lower among asthma patients who used ICS (median 32 parts per billion (ppb); 25-75% range 16-54) than among asthma patients who did not (51 ppb; 32-87) (p = 0.034). Among patients with COPD, eNO was inversely correlated with forced expiratory volume in one second, DL,CO and Sa,O2, and was positively correlated with the residual lung volume/total lung capacity ratio. Among patients with asthma, no significant correlations were found. Exhaled nitric oxide is increased in patients with chronic obstructive pulmonary disease, an increase that is influenced by structural abnormalities of tobacco-induced lung damage.     

Relationship between extent of pulmonary emphysema by high-resolution computed tomography and lung elastic recoil in patients with chronic obstructive pulmonary disease

We investigated the relationship between the extent of pulmonary emphysema, assessed by quantitative high-resolution computed tomography (HRCT), and lung mechanics in 24 patients with chronic obstructive pulmonary disease (COPD). The extent of emphysema was quantified as the relative lung area with CT numbers < -950 Hounsfield Units (HU). Patients with COPD had severe airflow obstruction (FEV(1) 35 +/- 15% pred) and severe reduction of CO diffusion constant (DCO/VA 37 +/- 19% pred). Maximal static elastic recoil pressure (Pst(max)) averaged 54 +/- 24% predicted, and the exponential constant K of pressure-volume curves was 258 +/- 116% predicted. Relative lung area with CT numbers < -950 HU averaged 21 +/- 11% (range 1 to 38%). It showed a highly significant negative correlation with DCO/VA (r = -0.84, p < 0.0001), a weak correlation with FEV(1)% predicted, and no correlation with either Pst(max) or constant K. A significant relationship was found between the natural logarithm of K and the full width at half maximum of the frequency distribution of CT numbers, taken as an index of the heterogeneity of lung density (r = 0.68, p < 0.0005). We conclude that currently used methods of assessing the extent of emphysema by HRCT closely reflect the reduction of CO diffusion constant, but cannot predict the elastic properties of the lung tissue.     

Airway dimensions and pulmonary function in chronic obstructive pulmonary disease and bronchial asthma

Background and objective: COPD and bronchial asthma are chronic airway diseases with a different pathogenesis. Comparisons of differences in airway calibre by bronchial generation between these diseases and their importance to pulmonary function have not been fully studied. We investigated airway calibre and wall thickness in relation to pulmonary function in patients with asthma, COPD, asthma plus emphysema and normal subjects using CT. Methods: Sixty‐three asthmatic patients, 46 COPD, 23 patients with asthma plus emphysema and 61 control subjects were studied cross‐sectionally. We used a software with curved multiplanar reconstruction to measure airway dimensions from 3rd‐ to 6th‐generation bronchi of the right lower posterior bronchus. Results: Patients with COPD had increased wall thickness, but the airway was not narrow from the 3rd‐(subsegmental) to 6th‐generation bronchi. Mean bronchial inner diameter (Di) of 3rd‐ to 6th‐generation bronchi in patients with asthma or asthma plus emphysema was smaller than that of COPD patients and normal subjects. Airway luminal area (Ai) of 5th‐generation bronchi most closely correlated with pulmonary function in patients with stable asthma. Although Di was similar in patients with asthma and asthma plus emphysema, the Ai of 6th‐generation bronchi correlated significantly with pulmonary function in patients with asthma plus emphysema. Conclusions: Airway calibre in asthma may be smaller than in COPD. Airflow limitations correlated more closely with peripheral Ai in patients with asthma plus emphysema than in patients with asthma alone.     

Similarity and differences in elderly patients with fixed airflow obstruction by asthma and by chronic obstructive pulmonary disease

BACKGROUND: Epidemiologic studies have demonstrated that elderly patients with fixed airflow obstruction can be affected by asthma or chronic obstructive pulmonary disease (COPD). METHODS: We studied 49 consecutive elderly outpatients, presenting fixed airflow obstruction, by clinical history (smoking), pulmonary function tests, blood gas analysis, and induced sputum. RESULTS: The age was not different in patients with COPD (n=28) and asthma (n=21) (70.2+/-3.9 years vs. 69.6+/-3.7 years), also the degree of fixed airflow obstruction was similar (FEV1: 58.3+/-1.5% vs. 59.0+/-1.4% of predicted). Patients with asthma had significantly more eosinophils in peripheral blood (0.43+/-0.05x10(-3)microL vs. 0.27+/-0.1x10(-3)microL, P<0.0001), and in induced sputum (5.0% [(p25th and p75th) 5.0-6.0%] vs. 1.0% [(p25th and p75th) 0.01-1.0%]; P<0.0001), as well as serum ECP (18.6+/-4.9ng/mL vs. 7.7+/-4.7ng/mL, P<0.0001) and ECP in the induced sputum (31.6+/-2.9ng/mL vs. 5.6+/-4.9ng/mL, P<0.0001). Finally, in induced sputum the eosinophils EG2+ were higher in patients with asthma than in patients with COPD (40.5 [(p25th and p75th) 39.3-44.3] MFI vs. 3.9 [(p25th and p75th) 0-11.4] MFI, P<0.0001). They also had significantly higher diffusing capacity, and a greater reversibility to steroids, after 14-day course of therapy, whereas the reversibility to 400microg of salbutamol was similar. CONCLUSION: Despite similar fixed airflow obstruction, elderly patients with asthma have distinct characteristics compared with patients with COPD.     

Respiratory drive in patients with chronic obstructive pulmonary disease

Respiratory drive (deltaP 0.1/deltaPCO2) and ventilatory response (deltaVE/deltaPCO2) to CO2 has been estimated in 20 normal subjects and 28 patients with chronic obstructive pulmonary disease (COPD). In patients with COPD, drive and ventilatory response to CO2 were diminished, but no statistical correlation with FEV1, MBC, TLC, FRC, RV/TLC was found. A statistically negative correlation was found between blood bicarbonate and drive or ventilatory response to CO2. Patients with emphysema and normal PaCO2 demonstrated normal deltaP 0.1/deltaPCO2. In contrast, patients with chronic bronchitis with the same pulmonary function abnormalities and hypercapnia had significant diminution of the deltaP 0.1/deltaPCO2. Therefore, we feel that pulmonary function abnormalities alone cannot explain the deltaP 0.1/deltaPCO2 decrease; in most cases there sould coexist a diminished respiratory sensitivity.     

Underdiagnosis of chronic obstructive pulmonary disease in Northern Sweden.

OBJECTIVE: To assess underdiagnosis of chronic obstructive pulmonary disease. MATERIAL AND METHODS: Two cross-sectional studies of respiratory symptoms and diseases in two population samples of the same age living in the same areas in northern Sweden were performed 6 years apart. In 1986, 5698 (86%) out of 6610 subjects aged 35-36, 50-51 and 65-66 years responded to a postal questionnaire. In 1992 an identical study was performed, and 5617 subjects (87%) out of 6434 responded. Lung function measurements were performed in stratified samples. RESULTS: Of the subjects diagnosed with chronic bronchitis only 25% in 1986 and 23% in 1992 had been diagnosed prior to the study as having chronic bronchitis, emphysema or chronic obstructive pulmonary disease (COPD). Chronic airflow limitation (CAL), used as a surrogate variable for COPD and defined as FEV1/VC <70% and FEV1 <80% of predicted value, was found in 171 subjects in 1986-1987 (12% of the examined subjects), and 166 subjects in 1993-1994 (11%). In 1986-1987, 26% of the subjects with CAL had been diagnosed as having chronic bronchitis or emphysema prior to the survey, while a diagnosis of either asthma, chronic bronchitis or emphysema, or use of asthma medicines, was found in 58%. The corresponding figures in 1993-1994 were 31% and 63%, respectively. The great majority of the subjects with CAL had recurrent wheeze, dyspnoea and chronic productive cough. CONCLUSION: Approximately 60% of the subjects with chronic airflow limitation had been diagnosed prior to the survey as having asthma, chronic bronchitis or emphysema, or were using asthma medicines. The results were similar in 1986-1987 and 1993-1994.     

210例入院诊断为慢性阻塞性肺疾病患者的PaO_2/PaCO_2分析

目的:分析入院第一诊断为慢性阻塞性肺疾病(COPD)患者的血气结果,探讨动脉血氧分压/动脉血二氧化碳分压(PaO2/PaCO2)比值在临床诊断与鉴别诊断中的价值。方法:回顾性分析了以第一诊断为COPD急性加重入院210例患者的临床资料,按出院第一诊断分为COPD急性加重组、肺血栓栓塞症(PTE)组、阻塞性睡眠呼吸暂停低通气综合征(OSAHS)组、哮喘组及间质性肺疾病组,将COPD急性加重组与其余4组患者吸氧前后的PaO2/PaCO2比值及PaCO2分别进行比较,观察2个指标在COPD急性加重组与其余4组间的差异是否有统计学意义。结果:1·210例中,出院第一诊断为COPD急性加重者154例(74%),PTE21例(10%)、OSAHS11例(5%)、哮喘15例(7%)、间质性肺疾病9例(4%),即:非COPD急性加重56例(26%)。2·COPD组与其他组比较显示:吸氧前及吸氧后,COPD组的PaO2/PaCO2比值明显低于PTE组与哮喘组,差异具有统计学意义;COPD组与间质性肺疾病组比较,PaCO2明显升高,有统计学意义。3·若取PaO2/PaCO2比值≤1·0同时PaCO2值≥45mmHg,则PTE组及哮喘组均为0例,即:可除外PTE及哮喘。结论:吸氧前后测定PaO2/PaCO2比值并联合PaCO2值对鉴别COPD与PTE、哮喘有一定的临床意义,但与OSAHS、间质性肺疾病的鉴别意义有限。PaO2/PaCO2比值计算方法简便,对临床有借鉴价值。     

Increased oxygen pulse after lung volume reduction surgery is associated with reduced dynamic hyperinflation

Stroke volume augmentation during exercise is limited in chronic obstructive pulmonary disease patients because of decreased preload from dynamic hyperinflation (DH). We hypothesised that oxygen pulse and pulse pressure (PP) improve following lung volume reduction surgery (LVRS), and the magnitude of improvement correlates with reduction in DH. We compared 16 emphysema patients undergoing LVRS with six emphysema patients not undergoing LVRS. Oxygen pulse and PP were calculated from maximal cardiopulmonary exercise tests at baseline and 6 months. End-expiratory lung volume (EELV)/total lung capacity (TLC) represented DH. Comparisons were made between baseline and 6 months at metabolic isotimes (per cent maximal carbon dioxide production (V'(CO(2),max))). At baseline, the LVRS group was older with higher forced expiratory volume in 1 s, but had similar hyperinflation to the non-LVRS group. At 6 months, oxygen pulse (50%, 75%, and 100% V'(CO(2),max)) and PP (50% and 75% V'(CO(2),max)) increased in the LVRS, but not in the non-LVRS group. Baseline functional residual capacity/TLC inversely correlated with resting oxygen pulse (r= -0.449, p=0.04). Decreased EELV/TLC correlated with increased oxygen pulse at 75% (r= -0.487, p=0.02) and 100% V'(CO(2),max) (r= -0.548, p=0.008). LVRS led to increased oxygen pulse and PP during exercise at metabolic isotimes 6 months following surgery. Reductions in DH correlated with increases in oxygen pulse during exercise. Reducing lung volume may improve stroke volume response to exercise by decreasing DH.