不同程度的慢性阻塞性肺疾病对支气管舒张试验的反应性差异

目的 探讨不同严重程度的慢性阻塞性肺疾病( COPD)患者对支气管舒张试验的反应性差异.方法 入选Ⅰ～Ⅳ级COPD稳定期患者共411例,采用支气管舒张试验比较支气管舒张前后第1秒用力呼气容积(FEV1)、用力肺活量(FVC)和深吸气量(IC)的改变值和改变率.结果 支气管舒张试验后,COPD患者的FEV1、FVC和IC均有增加,比试验前差异有统计学意义(P＜0.01).随着COPD严重程度的增加,FEV1的改变值逐渐减少,而FVC和IC改变值却逐渐增加.结论 随着COPD的严重程度加重,吸入支气管舒张剂后,FVC和IC改变值越大,FVC和IC是重度COPD患者对支气管舒张剂反应性的指标.     

呼吸疾病研究所呼气相气道内负压法检测呼气流速受限在支气管哮喘患者中的应用

目的 探讨支气管哮喘(简称哮喘)患者呼气流速受限(EFL)与呼吸困难严重程度的相关性,观察吸入支气管扩张剂对哮喘患者EFL的影响.方法 采用呼气相气道内负压法(NEP)检测65例哮喘患者支气管扩张试验前、后(吸入沙丁胺醇400 μg)EFL情况.结果 65例哮喘患者中有26例(40%)出现EFL,其中11 例仅仰卧位时出现,15例仰卧位及坐位均出现.EFL和无EFL者(N-EFL)第一秒用力呼气容积占预计值百分比(FEV1占预计值%)分别为(52±15)%、( 77±18)%,两组比较差异有统计学意义(t＝5.822,P＜0.01).仅仰卧位有EFL(S-EFL)者和仰卧位、坐位均有EFL(SS-EFL)者FEV1占预计值%分别为(64±10)%、(43±12)%,两组比较差异有统计学意义(t值分别为2.283、6.694,P分别＜0.01、＜0.05).3分法和5分法EFL均与FEV1占预计值%呈负相关(r值分别为-0.637、-0.630,P均＜0.01).第一秒用力呼气容积(FEV1)与加拿大医学研究委员会推荐的呼吸困难严重程度分级标准(MRC评分)呈负相关(r=-0.501,P＜0.01),3分法和5分法EFL均与MRC评分呈正相关(r值分别为0.627、0.636,P均＜0.01).17例FEV1占预计值%＜70%并存在EFL的患者吸入沙丁胺醇后,9例EFL完全消失,5例从SS-EFL变为S-EFL,吸入沙丁胺醇后3分法和5分法EFL评分均较吸入前差异有统计学意义(t值分别为6.769、6.010,P均＜0.01).结论 与FEV1比较,EFL与哮喘患者呼吸困难严重程度相关性更强,可作为评价患者呼吸困难严重程度更可靠的客观指标.哮喘患者EFL可被吸入支气管扩张剂逆转,即表现为可逆性EFL.     

慢性阻塞性肺疾病患者深吸气量与生命质量的关系

目的 探讨COPD患者深吸气量等肺功能指标与生命质量的关系.方法 2006年1月至2007年3月北京大学第三医院门诊的COPD稳定期患者62例,其中男55例,女7例;年龄43～79岁,平均年龄(66±8)岁.均进行肺容量、肺通气功能和小气道功能检查,并经圣乔治呼吸问卷(SGRQ)评分,采用Pearson直线相关分析SGRQ的分值与总分、SGRQ评分与肺功能指标之间的相关性.结果 62例COPD稳定期患者的SGRQ总分为(43±17)分,其中呼吸症状分值为(54±23)分,活动受限分值为(54±19)分,疾病影响分值为(33±20)分;肺功能检查结果中FEV_1占预计值%为(43±13)%,FEV_1/FVC为(52±11)%,残气量占预计值%为(194±50)%,残气量/肺总量为(166±31)%,深吸气量占预计值%为(74±21)%.深吸气量占预计值%、残气量占预计值%、残气量/肺总量、FEV,占预计值%、FEV./FVC、呼气峰流量、用力呼出50%肺活量时呼气流量(FEF_(50%))、用力呼出25%肺活量时呼气流量(FE_(25%))和最大呼气中段流量(MMEF)与SGRQ总分均呈负相关,其中通气功能指标的相关系数为-0.336～-0.479,小气道功能指标的相关系数为-0.368～-0.411,而深吸气量占预计值%和SGRQ的3个能区分值和总分相关性最好,相关系数为-0.418～-0.521,均P＜0.05.SGRQ的3个能区分值中呼吸症状和肺功能无显著相关性.结论 肺功能检查中肺容量测定、肺通气功能和小气道功能均与COPD患者的生命质量相关,深吸气量占预计值%和FEV_1占预计值%应联合作为临床评价COPD患者的客观指标.     

呼气相气道内负压法检测呼气流速受限在慢性阻塞性肺疾病中的应用

目的探讨慢性阻塞性肺疾病(COPD)患者呼气流速受限(EFL)与呼吸困难严重程度的相关性,并观察吸入支气管扩张剂对 COPD 患者 EFL 的影响。方法采用呼气相气道内负压法(NEP)检测33例 COPD 患者支气管扩张试验前、后(吸入沙丁胺醇400μg)EFL 情况,其中男31例,女2例,年龄46～78岁,平均年龄(63±8)岁。结果 33例 COPD 患者中23例(70%)出现 EFL,其中11例(33%)仅仰卧位出现 EFL,12例(36%)仰卧位及坐位均出现 EFL。无 EFL 患者与 EFL 患者第一秒用力呼气容积占预计值百分比(FEV_1占预计值%)分别为(66±16)%和(31±10)%,差异有统计学意义(t=7.601、P<0.01),仰卧位及坐位均出现 EFL 患者的 FEV_1占预计值%最低[(24±7)%]。3分法和5分法 EFL 均与 FEV_1呈显著负相关(r=-0.836和-0.818,P 均<0.01)。3分法和5分法 EFL 均与医学研究委员会(MRC)推荐的呼吸困难严重程度分级评分标准(简称 MRC 呼吸困难评分)呈显著正相关(r=0.903和0.912,P均<0.01)。多元回归分析结果显示,5分法 EFL 和FEV_1对 MRC 呼吸困难评分的预测性均有统计学意义(标准化偏回归系数分别为0.679、-0.265,P分别为<0.01、0.029),但5分法 EFL 比 FEV_1对 MRC 呼吸困难评分的预测性更强。23例吸入沙丁胺醇前存在 EFL 患者,吸入后全部患者 EFL 仍然存在。结论与 FEV_1比较,EFL 对 COPD 患者呼吸困难严重程度预测性更强,可作为评价 COPD 患者呼吸困难严重程度更可靠的客观指标。COPD 患者的 EFL 不能被吸入支气管扩张剂逆转,即表现为 EFL 的不可逆性。     

慢性阻塞性肺病患者肺功能与心腔大小及心功能不全的相关性

目的研究慢性阻塞性肺病(COPD)患者肺功能与心腔大小及心功能不全的相关性。方法选择COPD患者120例,全球阻塞性肺病创议(GOLD)肺功能分级Ⅰ~Ⅳ级,评估其肺功能:第1秒用力呼气量/用力肺活量(FEV1/FVC)、FEV1占预计值百分比、残气量占预计值百分比、深吸气量/肺总量(IC/TLC)、一氧化碳弥散量(DLCO)占预计值百分比,并通过超声心动图检查对心腔大小、左室收缩与舒张功能、右室收缩和舒张的整体功能(Tei指数)及舒张期肺动脉压进行评估。结果随着COPD患者GOLD肺功能分级的升高,所有心腔均缩小(P0.05)。肺功能相关变量与心腔大小高度相关。与气道阻塞或DLCO相比,静态充气过度(IC/TLC)与心腔大小之间的相关性最好。对体表面积进行调整后,IC/TLC是心腔大小的独立预测因素。相比于IC/TLC0.25的患者,IC/TLC≤0.25的患者左心室舒张功能明显受损(P0.05),右室Tei指数明显升高(P0.05)。结论随着COPD严重程度的增加,会出现心腔缩小,使左室舒张功能和右室整体功能受损。     

不同HRCT表型的COPD患者对长效β2受体激动剂/吸入型糖皮质激素的治疗应答性比较

目的:探讨不同高分辨CT(HRCT)表型的慢性阻塞性肺疾病(COPD)患者对长效β_2受体激动剂/吸入型糖皮质激素治疗的应答性。方法:选取217例COPD患者,根据HRCT表现分为A型72例、E型80例和M型65例,观察3组治疗前、后肺功能情况[第1秒用力呼气容积占预计值百分比(FEV_1%预计值)、残气量占预计值百分比(RV%预计值)、深吸气量占预计值百分比(IC%预计值)、FEV_1/FVC、肺总量百分比(TLC%预计值)、第1秒用力呼气容积(FEV_1)、肺总量(TLC)、深吸气量(IC)、残气量(RV)]。结果:M型体重指数(BMI)为(20.12±3.22)kg/m~2,明显低于A型和E型组(P0.05);M型组FEV_1%预计值和RV%预计值分别为(47.52±9.80)%和(138.89±52.29)%,明显低于A型和E型组(均P0.05),IC%预计值为(87.71±13.26)%,明显高于A型和E型组(P0.05)。治疗后A型组FEV_1、TLC、IC和RV改善值分别为(0.35±0.09)L、(-0.53±0.12)L、(0.17±0.06)L和(-0.60±0.11)L,明显优于E型和M型组(均P0.05)。结论:不同HRCT表型的COPD患者对长效β_2受体激动剂/吸入型糖皮质激素的治疗存在差异,其中A型COPD的疗效较好,肺功能改善明显。     

呼气流速受限在支气管舒张试验中的可行性

1994年Valta等首次提出了不需患者主动配合用力呼吸而仅在潮气呼吸下进行的呼气相气道内负压（NEP法）检测呼气流速受限（EFL）的方法，目前采用NEP法检测慢性阻塞性肺疾病（COPD）和支气管哮喘（简称哮喘）患者EFL的相关研究结果提示，EFL比第一秒用力呼气容积（FEV1）能更敏感反映COPD和哮喘患者呼吸困难和病情的严重程度。但目前有关NEP法检测EFL在支气管舒张试验中的可行性尚不明确。我们采用NEP法检测COPD和哮喘患者吸入支气管舒张剂沙丁胺醇前、后EFL的变化，并与常规FEV1判断指标进行比较，探讨NEP法检测EFL在支气管舒张试验中的可行性。     

稳定期慢性阻塞性肺疾病患者的气道阻力与运动相关呼吸困难肺功能参数的关系

目的观察稳定期慢性阻塞性肺疾病(COPD)患者的各项气道阻力(Raw)参数与运动相关呼吸困难肺功能参数的相关关系。方法前瞻性纳入上海交通大学附属胸科医院和第一人民医院门诊稳定期COPD患者180例,根据慢性阻塞性肺疾病全球倡议(GOLD 2017版)制订的肺功能诊断标准分为Ⅰ-Ⅳ级4组,受试前8 h内均未应用支气管舒张剂。所有患者在吸入沙丁胺醇400μg后接受常规肺功能和气道阻力测试。同期选择42例成年健康体检者作为对照组。结果Ⅱ级以上COPD患者的第1秒用力呼气容积和呼出50%肺活量时流量均显著低于健康成年人和Ⅰ级COPD患者,总气道阻力、有效气道阻力、吸气阻力和呼气阻力则呈进行性增高。Ⅲ-Ⅳ级COPD患者的深吸气量占预计值百分比(IC%pred)<80%,同时改良英国医学研究委员会呼吸困难量表评分超过2分;7例Ⅲ级(13.2%)和14例Ⅳ级COPD患者(33.3%)的吸气分数(IC/TLC)≤25%,而仅有1例Ⅱ级COPD患者的IC/TLC≤25%(1.9%)。结论稳定期中重度COPD患者呼出气流受限趋于加重,Raw各项参数中呼气阻力增高尤为显著。Ⅲ-Ⅳ级COPD患者更易出现运动相关呼吸困难症状,且IC/TLC≤25%。     

50例咳嗽变异型哮喘肺功能临床分析

对比分析典型哮喘患者40例与正常组健康人40例和咳嗽变异型哮喘患者50例的第一秒用力呼气量(FEV1)、用力肺活量(FVC)、第一秒用力呼气量FEV1占FVC比值(FEV1/FVC)、最高呼气流速(PEF)、残气量(RV)及残气量/肺总量(RV/TLC)指标。结果 FEV1、FVC、FEV1/FVC及PEF等肺通气功能指标:正常组最高,咳嗽变异型哮喘次之,而典型哮喘最低,(P0.05),在激发试验前后咳嗽变异型哮喘患者肺功能存在明显可逆性改变。结论咳嗽变异型哮喘存在可逆性气流受限,确诊需要完善肺功能及支气管激发试验(BPT)或支气管舒张试验(BDT)试验。(当患者FEV1≥70%预计值时,可进一步作支气管激发试验;FEV170%预计值提示有气道阻塞时,宜作支气管舒张试验)~([1])     

不同表型的COPD患者对长效b2受体激动剂/吸入型糖皮质激素的治疗应答性比较

【】目的 探讨不同表型的慢性阻塞性肺疾病(COPD)患者对长效b2受体激动剂/吸入型糖皮质激素治疗的应答性。方法 选取2014年2月至2016年10月在我院治疗的COPD患者217例,其中肺气肿型COPD患者94例,慢性支气管炎型COPD患者123例,观察两组治疗前后肺功能情况。结果 慢性支气管炎型组体重指数(BMI)为(24.13±3.72)kg/m2,明显高于肺气肿型组(p＜0.05);肺气肿型组第1秒用力呼气容积占预计值百分比(FEV1%预计值)和残气量占预计值百分比(RV%预计值)分别为(47.52±9.80)%和(138.89±52.29)%,明显低于慢性支气管炎型组(p＜0.05),而深呼气量占预计值百分比(IC%预计值)为(87.71±13.26)%,明显高于慢性支气管炎型组(p＜0.05);慢性支气管炎型组治疗前后第1秒用力呼气容积(FEV1)、肺总量(TLC)、深吸气量(IC)和残气量(RV)改善值分别为(0.35±0.09)L、(-0.53±0.12)L、(0.17±0.06)L和(-0.60±0.11)L,明显优于肺气肿型组(p＜0.05)。结论 不同表型的COPD患者对长效b2受体激动剂/吸入型糖皮质激素的治疗存在差异,其中慢性支气管炎型COPD的治疗效果较好,肺功能改善明显。     

Dynamic hyperinflation and flow limitation during methacholine-induced bronchoconstriction in asthma.

Although persistent activation of the inspiratory muscles and narrowing of the glottic aperture during expiration have been indicated as relevant mechanisms leading to dynamic hyperinflation in acute asthma, expiratory flow limitation (EFL) has recently been proposed as a possible triggering factor for increasing endexpiratory lung volume (EELV). To establish whether the attainment of maximal flow rate during tidal expiration could elicit dynamic elevation of EELV, breathing pattern, change in EELV by measuring inspiratory capacity (IC) and occurrence of EFL by the negative expiratory pressure (NEP) method were monitored in 10 stable asthmatic subjects during methacholine-induced, progressive bronchoconstriction in seated position. Change in dyspnoea was scored using the Borg scale. At maximum response forced expiratory volume in one second (FEV1) fell on average by 45+/-2% (p<0.001 versus control), while IC decreased 29+/-2%, (by 0.89+/-0.07 L, (p<0.01 versus control)). Only 2 subjects exhibited EFL at the end of methacholine challenge. In 7 subjects EELV started to increase before the occurrence of EFL. Dyspnoea, which increased from 0.2+/-0.1 to 5.5+/-1.0 (Borg scale) at maximum response (p<0.001), was significantly related to the level of bronchoconstriction as assessed by change in (delta)FEV1 (r=0.72; p<0.001) and to dynamic hyperinflation as measured by deltaIC (r=0.50; p<0.001). However, for both deltaFEV1 and deltaIC the slope of the relationship with increasing dyspnoea was highly variable among the subjects. It is concluded that in acute methacholine-induced bronchoconstriction, dynamic hyperinflation may occur in the absence of expiratory flow limitation and that expiratory flow limitation does not represent the triggering factor to generate dynamic hyperinflation. In these circumstances, dyspnoea appears to be related to the increase in end-expiratory lung volume and not to the onset of expiratory flow limitation.     

COPD和哮喘患者支气管舒张实验用力肺活量和呼气容积的变化

目的 探讨COPD和哮喘患者支气管舒张实验用力肺活量和呼气容积变化.方法 随机选取COPD急性加重期78例和哮喘急性发作期64例,采用支气管舒张实验比较COPD和哮喘患者实验前后用力肺活量(FVC)、一秒用力呼气容积(FEV1)的增加量和增加率.结果 支气管舒张实验后,COPD患者的用力肺活量(FVC)的增加量191 ml,较舒张前增加12.93%,而一秒用力呼气容积(FEV1)的增加量63 ml,较舒张前增加10.01%;哮喘患者的用力肺活量(FVC)的增加量363 ml,较舒张前增加15.34%,而一秒用力呼气容积(FEV1)的增加量289 ml,较舒张前增加23.57%.结论 COPD患者支气管舒张试验后用力肺活量的增加幅度大于呼气容积的增加幅度,而哮喘患者正好相反,因此用力肺活量可鉴别COPD和哮喘患者病情的客观指标.     

Inspiratory capacity and forced expiratory volume in the first second in exacerbation of chronic obstructive pulmonary disease

Object: Periodic exacerbations of symptoms are the major cause of morbidity, mortality and health care costs in patients with chronic obstructive pulmonary disease (COPD). Dyspnea is the major factor affecting the comfort of patients in the exacerbation of COPD. In this study, we aimed to compare the value of forced expiratory volume in the first second (FEV₁) and inspiratory capacity (IC) measured before and after treatment in exacerbations and in the improvement in dyspnea. Methods: Eighty‐seven patients (male/female, 80/7; mean age, 63 ± 7) with COPD exacerbation were included in this study. All subjects underwent spirometric tests on the first day and at the end of treatment. The subjects were asked to quantify the sensation of dyspnea that was described to them as a nonspecific discomfort associated with the act of breathing. The patients quantified dyspnea by pointing to a score on a large Borg scale from 0 to 10 arbitrary units. In the beginning and at the end of treatment, forced vital capacity (FVC), FEV₁, forced expiratory flow rate between 25% and 75% of FVC (FEF25–75), peak expiratory flow rate (PEF), IC and Borg score (BS) values were compared. Results: After treatment of COPD exacerbations, FEV₁, FEF25–75, PEF and IC significantly increased, and the BS significantly decreased compared to the initial values. The increase in IC was more significantly correlated with the improvement in BS compared with FEV₁. Admission and discharge day BS was negatively correlated with FEV₁, FEF25–75 and IC. Conclusion: We have shown a more dramatic improvement in IC compared with FEV₁ in patients treated as a result of acute exacerbation of COPD. These data suggest that IC may be more useful than FEV₁ during acute exacerbation of COPD. Moreover, IC better reflects the severity of dyspnea in these patients. Please cite this paper as: Yetkin O and Gunen H. Inspiratory capacity and forced expiratory volume in the first second in exacerbation of chronic obstructive pulmonary disease. The Clinical Respiratory Journal 2008; 2: 36–40.     

Does expiratory flow limitation predict chronic dyspnoea in adults with cystic fibrosis?

Tidal expiratory flow limitation (EFL) may promote dynamic hyperinflation and contribute to chronic dyspnoea. The purpose of this study was to assess the contribution of EFL to chronic dyspnoea in adults with cystic fibrosis (CF). The presence of EFL was determined in 102 adults with stable CF (forced expiratory volume in one second (FEV1) 17.3-91.5% predicted) and 20 age-matched control subjects using the negative expiratory pressure technique. Measurements of inspiratory capacity (IC) and spirometry were performed, and chronic dyspnoea was evaluated using the modified Medical Research Council scale. EFL was present in 34 subjects (33%), with 18 subjects flow limited in the sitting position and 16 subjects flow limited only in the supine position. Flow limitation in the sitting position was associated with older age and lower FEV1 compared with flow-limited supine position and non-flow-limited subjects. A significant reduction in IC accompanied EFL in both the sitting and supine positions. Flow limitation in the sitting position was associated with significantly higher levels of chronic dyspnoea. Ordinal regression analysis indicated that EFL was the best predictor of chronic dyspnoea in a model that included FEV1 % pred. Expiratory flow limitation in cystic fibrosis is associated with reduced forced expiratory volume in one second, older age and dynamic hyperinflation. Expiratory flow limitation significantly contributes to chronic dyspnoea in cystic fibrosis.     

Reproducibility of the negative expiratory pressure technique in COPD

BACKGROUND: Tidal expiratory flow limitation (EFL) contributes to chronic dyspnea and exercise intolerance in COPD patients. It can be assessed with the negative expiratory pressure (NEP) technique and is expressed as either the percentage of the tidal volume over which EFL occurs (EFL%Vt) or according to more detailed three-point or five-point scoring systems. The aim of this study was to evaluate the reproducibility of the NEP technique in COPD patients. METHODS: Tidal EFL was evaluated with NEP in 18 subjects with stable COPD (FEV(1) range, 18 to 75% predicted) on two occasions (mean retest interval, 8.2 days) by the same rater. Agreement between testing occasions was assessed with the kappa statistic for the 3-point and 5-point EFL scores, and with the coefficient of repeatability for EFL%Vt. RESULTS: On the first testing occasion, nine subjects had no EFL, four subjects had EFL in the supine position, and five subjects had EFL in the sitting and the supine position. Using the 3-point score, agreement was present in 14 of 18 subjects at time 2 (kappa = 0.66), indicating substantial agreement. Using the 5-point score, agreement was seen in 13 of 18 subjects (kappa = 0.61), also indicating substantial agreement. The reproducibility of EFL%Vt measurements was lower than that required to reliably detect clinical change in both the sitting and supine positions (coefficient of repeatability, 37% and 58%, respectively). CONCLUSIONS: The 3-point and 5-point scores provide a reproducible assessment of EFL in COPD patients. The classification of EFL as a percentage of tidal volume is less reproducible, and large changes are required to be confident that real clinical change has occurred.     

Lung function in patients with chronic airflow obstruction due to tuberculous destroyed lung

Lung function in cases of chronic airflow obstruction (CAO) due to tuberculous destroyed lung, which is still common in Korea, has not been objectively investigated. We evaluated lung functions and postbronchodilator responses in 21 CAO patients with a forced expiratory volume in 1 s (FEV1) of 30-65% of the predicted value, and compared some of these results with those of age-, sex- and FEV1% predicted-matched patients with chronic obstructive pulmonary disease (COPD). In addition, we analyzed the lung functions of CAO patients with respect to wheezing. The forced vital capacity (FVC) (P < 0.05) and postbronchodilator FEV1 of CAO patients were lower than those of COPD patients (P < 0.05). When a positive bronchodilator response was defined as an absolute change of FEV1 (FEV1 delta(abs)) of more than 0.2 l (P < 0.05) and a percentage of initial FEV1 (FEV1 delta%init) of more than 12%, the positive rates in CAO patients were lower than in COPD patients (P < 0.05). Among the CAO patients, patients with wheezing showed lower forced expiratory flow 25%-75% (FEF(25-75%)) (P < 0.05) and higher airway resistance than those without wheezing (P < 0.05). CAO patients with wheezing were more responsive to bronchodilator than those without wheezing. Although the pathophysiology of CAO differs from that of COPD, bronchodilator therapy could be useful for treating CAO, especially in cases presenting with wheezing.     

Evaluation of bronchodilator responses in patients with "irreversible" emphysema.

Given the emerging physiological and clinical rationale for pharmacological lung-volume reduction, assessment of volume responses to bronchodilators is likely to be highly relevant in chronic obstructive pulmonary disease (COPD). The authors examined the magnitude of lung-volume reduction after acute bronchodilator treatment in patients with advanced emphysema. Eighty-four stable patients with emphysema (mean+/-SEM forced expiratory volume in one second (FEV1): 32+/-1% predicted) performed spirometry and body plethysmography before and 15-30 min after 200 microg salbutamol. Only irreversible patients with a postbronchodilator change in FEV1 <10% pred were considered in this study. Postsalbutamol, the majority of subjects (83%) had significant improvements in one or more lung volumes: on average, residual volume (RV), functional residual capacity (FRC), inspiratory capacity (IC), forced vital capacity and slow vital capacity changed by -18+/-2, -10+/-1, 8+/-1, 9+/-1 and 7+/-1% pred (p<0.0005 each). Total lung capacity (TLC) decreased 0.12+/-0.04 L (p<0.01). Change in IC reflected change in FRC (r=-0.60, p<0.0005), but more strongly in the 57% of patients with no significant change in TLC (r=-0.93, p<0.0005). The magnitude and frequency of volume responses were greatest in patients with the most severe COPD; for example, RV decreased by 0.51+/-0.09 L (23+/-4% pred) and 0.27+/-0.04 L (14+/-2% pred) in severe and moderate subgroups, respectively. Significant reductions in lung hyperinflation occurred in the absence of a change in forced expiratory volume in one second after low-dose salbutamol in a majority of patients with advanced emphysema; the greatest changes occurred in those with the most severe disease.     

Effect of indacaterol on dynamic lung hyperinflation and breathlessness in hyperinflated patients with COPD

Indacaterol is a novel, inhaled once-daily ultra long-acting β2-agonist for the treatment of COPD. This randomised, double-blind, placebo-controlled, two-period crossover study evaluated the effect of two-week treatment with indacaterol 300 μg on peak and isotime exercise inspiratory capacity (IC) in patients with COPD. Patients (40-80 years) with post-bronchodilator forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) < 70%, percent predicted FEV1 ≥ 40% and ≤ 80%, smoking history ≥ 20 pack-years and functional residual capacity > 120% of predicted normal were randomised to receive indacaterol 300 μg or placebo once-daily via a single-dose dry powder inhaler. Following 14 days of treatment, IC at peak and isotime during constant-load (80% of maximum workload) cycle ergometry was analysed using linear mixed-effects models. Safety and tolerability were also monitored. Twenty-seven patients (67% male; mean age, 61.3 years) were randomised; 24 completed the study. On Day 14, indacaterol showed statistically significant improvements over placebo in peak (317 mL [95% CI: 118-517]; p < 0.01) and isotime IC (268 mL [95% CI: 104-432]; p < 0.01). Statistically significant improvements were observed with indacaterol versus placebo on Day 14 for the following secondary endpoints: resting IC, trough FEV1, dyspnoea (BDI/TDI and Borg CR10 scale at isotime) and exercise endurance time. Indacaterol was well tolerated, with no serious adverse events or deaths. In conclusion, indacaterol 300 μg administered once-daily showed a clinically relevant increase in IC after 14 days of treatment, reflecting a reduction in dynamic hyperinflation.