肺栓塞患者运动耐力的评估

目的:探讨心肺运动试验(CPET)与6min步行实验(6MWT)、左室射血分数(LVEF)评估肺栓塞(PE)患者运动耐受能力的相关性。方法:17例确诊断为PE的患者经最佳治疗后,出院前给予CPET、6MWT以及超声心动图。结果:(1)6min步行距离与峰值氧耗(VO2peak)明显相关(r=0.667,P0.01);6min步行距离与无氧阈值氧耗(VO2AT)、二氧化碳通气斜率(VE/VCO2slope)均无相关性(r=0.458,r=-0.456,P0.05)。(2)LVEF与VO2peak、VO2AT、VE/VCO2slope均无相关性(r=0.435,r=0.357,r=-0.426,P0.05)。结论:6MWT能准确可靠地评估PE患者的运动耐受能力。     

CPET评估制定运动处方指导下的有氧运动对COPD患者心肺功能的影响

目的探讨应用心肺运动试验评估制定的运动处方指导下的有氧运动对稳定期慢性阻塞性肺病(chronic obsturctive pulmonary disease,COPD)患者心肺功能的影响。方法入选220例COPD患者,分为对照组100例和观察组120例,入组评估心肺运动试验(cardiopulmonary exercise testing,CPET)和6分钟步行试验(6 minute walk test,6MWT)。测得6分钟步行距离(6MWD)、最大摄氧量(VO_2max)、最大代谢当量(METs)、无氧阈(AT)、功率负荷(Work rate,WR)、用力肺活量(FVC)、第1秒用力呼气容积(FEV1)、FEV1/FVC、FEV1/pre%等指标。对照组常规药物治疗和日常活动,观察组在此基础上,根据CPET评估,制定运动处方,根据AT值确定运动强度,训练12周后复查上述指标。结果观察组康复训练12周后,各项指标结果与干预前比较显示:6MWD增加105.56m,VO_2max增加253.99ml/min,代谢当量增加1.25METs,AT值增加148.15ml/min,WRmax增加19.34W,上述各项值与干预前比较均有统计学意义(P0.05)。肺功能指标均有统计学意义(P0.05)。结论应用CPET评估心肺功能,制定个体化运动处方,指导稳定期COPD患者康复运动训练,能有效改善患者心肺功能。     

心肺运动试验对合并营养风险的老年COPD病人心肺功能的评估研究

目的采用心肺运动试验(CPET),探讨合并营养风险的老年慢性阻塞性肺疾病(COPD)病人的心肺功能。方法根据营养风险筛查2002(NRS-2002)标准,对入选的68例中重度COPD病人进行营养风险评估,分为无营养风险组(n=30)及有营养风险组(n=38)。采用CPET及6 min步行试验(6MWT)评估2组病人心肺功能,观察2组间最大分钟通气量(VE max)、第1秒用力呼气容积(FEV1)、第1秒用力呼气容积占预计值的百分比(FEV1%pre)、FEV1/用力肺活量(FVC)、峰值摄氧量(VO_2peak)、最大代谢当量(METs)、无氧阈(AT)、最大功率负荷(WR max)、氧脉搏(O2pulse)、每公斤体质量最大摄氧量(VO_2max/kg)、6 min步行距离(6MWD)等指标是否有差异。结果有营养风险组VO_2peak、METs、AT、O_2pulse、WRmax等指标均显著低于无营养风险组(P0. 05); 2组间VEmax、FEV1、FEV1/FVC、6MWD差异无统计学意义(P0. 05)。结论 CPET评估合并有营养风险的老年COPD病人,能早期了解病人的心肺功能,为老年COPD病人制定营养处方提供依据,以便早期帮助COPD病人心肺功能康复,同时,CPET评估较6MWT更为灵敏。     

运动心肺功能参数对轻度慢性阻塞性肺疾病患者康复治疗的指导作用

目的探讨运动心肺功能参数指导轻度慢性阻塞性肺疾病(COPD)康复治疗的价值。方法选择轻度COPD患者85例,随机分为运动康复组45例和常规康复组40例。运动康复组根据检查参数选择适当运动康复方案,常规康复组根据自身情况进行锻炼,疗程为半年。治疗前后两组行静态或运动心肺功能、心脏彩超检查,比较两组第1秒用力肺活量(FEV1)、用力肺活量(FVC)、左室射血分数(LVEF)、最大摄氧量(VO2max)、6 min步行距离(6 min WD)、最大负荷功率(LPmax)的差异。结果半年后两组FEV1/FVC、LVEF比较差异无统计学意义(P均>0.05);运动康复组VO2max、LPmax、6 min WD较常规康复组均明显改善(P均<0.05)。结论轻度COPD患者基于运动心肺试验参数指导下的康复治疗可以明显改善心肺功能。     

性别差异对中重度慢性阻塞性肺疾病患者运动耐力的影响

目的 比较中重度慢性阻塞性肺疾病(COPD)患者运动耐力的性别差异.方法 本研究对151例中、重度COPD患者的肺功能(PFT)和功率递增心肺运动试验(CPET)结果进行了分析.将患者分为Ⅱ级COPD组和Ⅲ级COPD组.并选择43例年龄、性别、身高、体质量相匹配的正常人作为对照组.本研究测定第1秒用力呼气容积(FEV1)、用力肺活量(FVC)、峰值运动功率(Peak Load)、峰值摄氧量(Peak (V)O2)、峰值心率(Peak HR)、峰值氧脉搏(Peak(V)O2/HR)、最大分钟通气量(M(V)E)、气促指数(M(V)E/MVV)等指标.本研究分别在不同COPD分级和性别之间分析比较了上述指标的差异.结果 Ⅱ级COPD组和Ⅲ级COPD组的女性患者的Peak (V)O2实/预％和Peak (V)O2/HR实/预％较同组男性更高(P值均＜0.05).Ⅲ级COPD男性患者的运动耐力较Ⅱ级有明显降低(P＜0.0001),然而,Ⅲ级、Ⅱ级COPD女性患者之间运动耐力差异无统计学意义(P=0.246).结论 在中、重度COPD患者中,男性运动耐力下降较女性更为严重,吸烟可能是造成这一差异的重要因素.     

戒烟时间对稳定期重度慢性阻塞性肺疾病患者运动耐力的影响

目的 通过比较重度慢性阻塞性肺疾病(COPD)男性患者戒烟6个月时与戒烟12个月时两次测得相关肺功能指标及心肺运动试验(cardiopulmonary exercise test,CPET)结果,探讨戒烟时间对稳定期重度COPD患者运动耐力的影响.方法 随访52例处于稳定期的重度COPD男性患者,分别于其戒烟6个月时及戒烟12个月时两次进行静态常规肺功能(pulmonary function test,PFT)及CPET,测定相关肺通气功能参数、心肺运动功能参数,并将两次测得数据进行配对样本t检验.结果 ①此52例COPD患者于戒烟6个月时和戒烟12个月时两次测得的PFT结果显示,FEV1、FEV1％pred、FEV1/FVC、D(1.)CO两组间比较差异无统计学意义(P＞0.05).戒烟12个月时的IC[(2.21±0.62)L]高于戒烟6个月时的IC[(1.83±0.47)L],差异有统计学意义(P＜0.05).戒烟12个月时的RV[(4.02±0.82)L]、TLC[(7.30±1.21)L]、RV/TLC[(51.43±7.67)％]均低于戒烟6个月时的RV[(4.75±0.26) L]、TLC[(7.71±0.84)L]、RV/TLC[(56.33±8.79)％],差异均有统计学意义(P＜0.05);②CPET测定结果显示,此52例COPD患者戒烟12个月时的Peak Load[(91.21±15.12)W]、Peak(v)O2[(1 327.21±281.42) ml/min]、Peak(v)O2 ％pred[(63.07±17.15)％]、Peak(v)O2/kg[(21.58±4.13)ml·min-1·kg-1]、Peak(v)E[(38.33±8.79)L/min]、dO2/dW1[(8.67±0.73)ml·min-1·watt-1]、Peak O2 pulse[(10.62±2.67)ml/beat]均高于戒烟6个月时的Peak Load[(81.26±16.32)w]、Peak (v)O2 [(1075.18±276.45) ml/min]、Peak(v)O2 ％pred[(54.13±16.14)％]、Peak(v)O2/kg[( 17.49±4.37)ml·min-1·kg-1]、Peak(v)E[(34.29±7.12)L/min]、dO2/dW1[(8.51±0.72)ml·min-1·watt-1]、Peak O2 pulse[(9.57±2.47)ml/beat],差异有统计学意义(P＜0.05)；戒烟12个月时的Lowest(v)E/(v)CO2[(28.38±3.4)]低于戒烟6个月时的Lower(v)E/(v)CO2[(31.5±3.21)],差异有统计学意义(P＜0.05);③PFT中IC改善值与CPET中Peak(v)O2、Peak(v)O2/kg、Peak(v)E、Lowest(v)E/(v)CO2的改善值有良好的相关性,而FEV1的改善值与上述CPET的参数改善无显著相关.结论 戒烟时间的长短能影响COPD患者综合心肺能力和运动耐量,戒烟对于重度COPD患者仍有较大意义.IC值对于预估COPD患者的运动耐力受损程度有较大意义.     

慢性心力衰竭病人6 min步行试验与代谢当量的相关性

目的:探讨慢性心力衰竭(CHF)病人6 min步行距离(6MWD)与代谢当量(MET)的相关性。方法:纳入符合射血分数降低标准的CHF病人60例,进行心肺运动试验(CPET)与2次6 min步行试验(6MWT)。采集2次6MWD、峰值摄氧量(VO₂peak)、无氧阈下代谢当量(METs-AT)、血氧饱和度(SpO₂)、心率等数据,采用线性回归分析建立6MWD与METs-AT之间的回归方程模型。结果:正式6MWT中6MWD、VO₂peak、METs均较预行6MWT显著提高,分别增加5.02%、7.83%及8.61%,差异有统计学意义(P<0.05),2次6MWT过程中,病人的心率、Borg评分、SpO₂变化趋势基本一致;正式6MWD与METs-AT相关存在线性关系(r=0.78),方程式中决定系数R2和常量均具有统计学差异(P<0.05);试验过程中未出现严重不良事件。结论:正式6MWT结果可作为评估运动耐量的准确测量指标,根据6MWT建立回归模型推导METs-AT适用于CHF病人的评估。     

70岁以上慢性阻塞性肺疾病患者运动训练的康复效果研究

目的探讨70岁以上老年慢性阻塞性肺疾病(COPD)患者运动训练前、后肺功能、6 min步行试验(6MWT)及症状评分的变化。方法选择34例稳定期COPD患者,进行运动训练,包括呼吸训练、上肢肌力训练及全身有氧耐力训练,康复治疗前和6个月后分别测定用力肺活量(FVC)、第一秒用力肺活量(FEV1.0)、最大通气量(MVV)、残气量(RV)、肺总量(TLC)及6MWT运动距离;并进行症状评价。结果(1)运动训练后,6MWT运动距离[(357．5±16．6)m]较运动训练前[(326．2±19．3)m]提高,其差异有非常显著统计学意义(P=0．002);(2)与运动训练前相比, FVc、FEV1.0、MVV等指标有所改善,但差异无统计学意义(P>0．05);(3)运动训练后,咳嗽、咳痰、呼吸困难症状均有所改善。结论对70岁以上老年COPD患者进行低强度、简单的运动训练,可提高运动耐力,减轻症状,但不能显著提高患者的肺通气功能。     

慢性阻塞性肺疾病伴肺动脉高压对运动中气体交换的影响

目的:通过比较中重度慢性阻塞性肺疾病相关肺动脉高压(COPD-PH),与慢性阻塞性肺疾病无肺动脉高压(COPD-non PH),在运动中气体交换及运动耐量的差异,旨在为COPD-PH临床诊断、鉴别诊断、评估提供一定参考价值。方法:对54例处于稳定期的中重度慢性阻塞性肺疾病(COPD)患者依据肺动脉收缩压(PASP)分为两组,比较两组间血气分析、常规肺功能(PFT)、心肺运动试验(CPET)。结果:血气分析:COPD-PH的动脉氧分压(Pa O2)明显低于COPD-non PH(P0.01)。PFT:COPD-PH的第一秒用力呼气量(FEV1)、第一秒用力呼气量占预计值的百分比(FEV1%pred)及一氧化碳弥散量(DLco)均低于COPD-non PH(P0.05)。CPET:COPD-PH的峰值功率(Peak Load)、峰值摄氧量(Peak VO2)、峰值公斤摄氧量(Peak VO2/kg)、峰值分钟通气量(Peak VE)、Peak VE%pred及峰值氧脉搏(Peak O2pulse)均明显低于COPD-non PH(P0.01)。COPD-PH的峰值摄氧量占预计值的百分比(Peak VO2%pred)低于COPD-non PH(P0.05)。Pearson相关分析:PASP与DLco、Pa O2、Peak Load、Peak VO2及Peak O2pulse均呈负相关(P0.01)。结论:COPD-PH会导致患者肺换气功能明显受损、运动耐力明显下降,其降低程度与PASP存在相关性。对COPD行CPET,有助于早期发现COPD-PH。     

老年慢性阻塞性肺疾病患者心肺功能运动实验的安全性

目的 探讨老年慢性阻塞性肺疾病(COPD)患者进行心肺功能运动试验的安全性.方法 老年COPD组35人,成年对照组19人,老年对照组12人.受试者均进行静态肺功能和踏车下连续递增负荷心肺功能运动试验(CPET),测定经皮血氧饱和度(SpO2)、血压(BP)、呼吸频率(RR)等,并进行动态心电图监测,呼吸困难评分采用Borg评分.结果 所有受试者均能完成检查过程.老年COPD组主要因呼吸困难停止运动,74.29％的患者出现了SpO2下降超过4％,Ⅲ至Ⅳ级的患者下降较明显.少部分病人运动中可见心律失常及ST-T压低,无危及生命的心血管事件发生.半数以上患者可达到次级量以上心率.结论 稳定期老年COPD患者能够耐受症状限制性的最大运动量,老年COPD患者在严格监测生理学指标的情况下进行心肺功能运动试验是相对安全的.     

6-minute walk testing is more sensitive than maximal incremental cycle testing for detecting oxygen desaturation in patients with COPD

STUDY OBJECTIVES: Some respiratory patients exhibit oxygen desaturation during rehabilitative walking but not during maximal cardiopulmonary exercise testing (CPET). We evaluated exercise-induced desaturation during 6-min walk testing (6MWT) in comparison with CPET in patients with COPD and determined the reproducibility of the phenomenon. PATIENTS: We tested 80 consecutive patients with COPD (FEV(1), 62.4 +/- 2% predicted) and 10 patients with supplementary COPD (FEV(1), 59.1 +/- 5% predicted) [mean +/- SEM] to determine the reproducibility. MEASUREMENTS AND RESULTS: First, patients with COPD performed cycle CPET (first CPET [CPET-1]). Three days later, they performed two 6MWTs (first 6MWT [6MWT-1] and second 6MWT [6MWT-2]). Pulse oximetric saturation (SpO(2)) was recorded every minute in both tests. Three groups emerged: desaturation at 6MWT not observed at CPET (DND) [n = 23], desaturation in both tests (n = 16), and no desaturation in either test (n = 41). Second, to evaluate reproducibility, 10 additional subjects with COPD who exhibited desaturation during two successive 6MWTs but not in CPET performed a second CPET (CPET-2) and a single-bout 6MWT (6MWT-3) in a supplementary trial. When two CPETs were performed, lack of O(2) desaturation was noted in both. O(2) desaturation was confirmed in 6MWT-2 and 6MWT-3 (7.4 +/- 1% and 7.4 +/- 1.5%, respectively). CONCLUSION: Twenty-eight percent of patients with COPD presented DND. The phenomenon was reproducible and not protocol dependent, emphasizing the clinical interest of the 6MWT.     

Six-minute walking test in cystic fibrosis adults with mild to moderate lung disease: comparison to healthy subjects

The six-minute walking test (6MWT) has been widely utilized to evaluate global exercise capacity in patients with cystic fibrosis. The aim of this study was to assess the exercise capacity by 6MWT, measuring four outcome measures: walk distance, oxygensaturation and pulse rate during the walk, and breathlessness perception after the walk, in a group of cystic fibrosis adults with mild to moderate lung disease, and in healthy volunteers, as the control group. Moreover, the study examined the relationship between 6MWT outcome measures and pulmonary function in patients. Twenty-five adults (15 females, age range 18-39 years) with cystic fibrosis and 22 healthy volunteers (14 females, age range 20-45 years) performed a 6MWT following a standard protocol. Walk distance, oxygen saturation (SpO2) and pulse rate at rest and during walk, and breathlessness perception after walk assessed by visual analogue scale (VAS) were measured. Cystic fibrosis patients did notdiffer from healthy volunteers in walk distance (626 +/- 49 m vs. 652 +/- 46 m) and pulse rate. Patients significantly differed from healthy volunteers in SPO2 during the walk (mean SpO2) (P < 0.0001) and VAS (P < 0.0001). In patients, SPO2 during the walk significantly correlated with forced expiratory volume in 1 sec (FEV1) (P < 0.0001), residual volume (RV) (P < 0.001), resting SPO2 (base SpO2) (P < 0.001), and inspiratory capacity (IC) (P < 0.01). In addition, VAS significantly correlated with resting SPO2 (P < 0.01) and IC (P < 0.01).On the basis of regression equations by stepwise multiple regression analysis, SpO2 during walk was predicted by FEV1 (r2 = 0.60) and VAS by IC (r2 = 0.31), whereas walk distance was not reliably predicted by any assessed variables. This study showed that cystic fibrosis adults with mild to moderate lung disease covered a normal walk distance with unimpaired cardiac adaptation, but experienced a significant fall in oxygen saturation and an increased breathlessness perception during exercise. Resting pulmonary function was related to oxygen saturation and breathlessness perception during walk, but contributed significantly only tothe prediction of oxygen saturation. We suggest that 6MWT could be valuable for identifying patients who might experience oxygen desaturation and dyspnoea during demanding daily activities.     

摄氧量平均反应时间在重度慢性阻塞性肺疾病患者心肺功能评估中的应用研究

目的 探讨重度慢性阻塞性肺疾病(COPD)患者在心肺运动试验(cardiopulmonary exercise test,CPET)检测零负荷热身期中的摄氧量动力学改变特点,研究零负荷热身期间摄氧量平均反应时间(mean response time,MRT)与COPD患者心肺功能及常规肺功能的相关性,探讨MRT值评价重...     

Effects of Pulmonary Hypertension on Exercise Capacity in Patients With Chronic Obstructive Pulmonary Disease

IntroductionThe impact of pulmonary hypertension (PH) on exercise tolerance in chronic obstructive pulmonary disease (COPD) has not been fully elucidated. It is necessary to characterize pulmonary hemodynamics in patients with moderate to severe COPD in order to improve their management. The aim of the study was to determine whether in COPD the presence of PH is associated with reduced exercise tolerance in a cohort of stable COPD patients.MethodsCross-sectional analysis of 174 COPD patients clinically stable: 109 without PH and 65 with PH (COPD-PH). We assessed socio-demographic data, lung function, quality of life, dyspnea, cardiopulmonary exercise testing (CPET), constant workload endurance time (CWET), and six-minute walk test (6MWT). We elaborated a logistic regression model to explore the impact of PH on exercise capacity in COPD patients.ResultsCOPD-PH patients showed lower exercise capacity both at maximal (CPET) (43(20) versus 68(27) Watts and 50(19)% versus 71(18)% predicted peak oxygen consumption (VO₂peak), COPD-PH and COPD, respectively), and at submaximal tests (6MWT) (382(94) versus 486(95) m). In addition, the COPD-PH group had lower endurance time than the non-PH COPD group (265(113) s and 295(164) s, respectively).ConclusionsThe presence of PH is an independent factor that impairs exercise capacity in COPD.     

The body weight-walking distance product as related to lung function, anaerobic threshold and peak VO2 in COPD patients.

The product of walking distance and body weight (D x W) mimics the work of walking. We hypothesized the superiority of D x W to walking distance (D) alone in any correlation with lung function, anaerobic threshold (AT) and maximal oxygen uptake (VO2max). We further hypothesized that the D x W product for a 6-min walk test (6 MWT) would correlate with the AT and VO2max because all three are markers of exercise ability. Thirty-three male chronic obstructive pulmonary disease (COPD) patients with mean forced expiratory volume in 1 sec (FEV1) of 1.2+/-0.4 l (range 0.58-1.86 l) were enrolled. Six patients were excluded due to inability to achieve a maximal test. Lung function and self-assessed every-day activities using a oxygen-cost diagram were evaluated before entry of the study. A maximal effort ramp-pattern cardiopulmonary exercise test (CPET) and a 6 MWT were conducted in random order. Borg score, heart rate, and O2 saturation with pulse oximetry (SpO2) were measured during both exercise tests. VO2 AT and minute ventilation were also measured during the CPET. Correlations were sought between the distance covered in the 6 MWT, and the D x W product with AT, VO2max and other variables. The average D and D x W were 456 m and 27.5 kg km(-1), respectively. D x W was superior to D alone when correlated with the VO2max and AT determined from the CPET, while modestly correlated with the change (delta) in Borg score and delta SpO2 in the 6 MWT and self-assessed every-day activities. Distance x weight product was correlated with the AT and VO2max. In addition, D x W was better correlated with diffusing capacity for carbon monoxide and vital capacity than D alone. We conclude that D x W mimics the work of walking better than D and is suggested as a parameter for evaluation of patients' fitness if gas exchange measurements are not available.     

Six‐minute walk test: observed adverse events and oxygen desaturation in a large cohort of patients with chronic lung disease

Background: The 6‐min walk test (6MWT) is widely used to assess patients with chronic lung disease (CLD). Anecdotal reports and studies in small numbers of patients with CLD suggest that complications associated with the 6MWT are rare. This study reports the incidence of observed adverse events during the 6MWT in patients referred to an outpatient pulmonary rehabilitation service. Methods: Seven hundred and forty‐one patients with stable CLD (chronic obstructive pulmonary disease (COPD), n= 572) completed the 6MWT in accordance with a standardized protocol that included continuous monitoring of oxygen saturation (SpO₂) and heart rate (Polar). Results: Adverse events occurred in 43 tests (6%). One 6MWT was terminated by the tester because of chest pain and one patient developed persistent tachycardia and irregular pulse immediately following the test. In 35 tests, the tester instructed the patient to stop walking because of profound oxygen desaturation (SpO₂ < 80%). Six patients prematurely terminated the 6MWT because of symptoms. Forty‐seven per cent (n= 345) of patients exhibited significant oxygen desaturation (≥4% fall in SpO₂ to <90%). Pre‐exercise SpO₂ was a significant predictor of desaturation in the COPD (1.79, 1.54–2.08, adjusted odds ratio (OR), 95% confidence intervals) and ILD (OR 1.40, 1.11–1.77) cohorts with FEV₁ (forced expiratory volume in 1 s) also a predictor in COPD (OR 3.02, 1.77–5.15). Conclusion: Profound oxygen desaturation is the most common adverse event observed during the 6MWT in patients with stable ILD and COPD. We propose that the American Thoracic Society 6MWT guidelines are revised to recommend continuous monitoring of SpO₂ during the 6MWT in patients with ILD and COPD.     

Inaccuracy of Estimating Peak Work Rate from Six-Minute Walk Distance in Patients with COPD

Abstract

Introduction. The cardiopulmonary exercise test (CPET) and the 6-minute walk test (6MWT) are used to prescribe the appropriate training load for cycling and walking exercise in patients with chronic obstructive pulmonary disease (COPD). The primary aims were: (i) to compare estimated peak work rate (Wpeakestimated) derived from six existing Wpeak regression equations with actual peak work rate (Wpeakactual); and (ii) to derive a new Wpeak regression equation using six-minute walk distance (6MWD) and conventional outcome measures in COPD patients. Methods. In 2906 patients with COPD, existing Wpeak regression equations were used to estimate Wpeak using 6MWD and a new equation was derived after a stepwise multiple regression analysis. Results. The 6 existing Wpeak regression equations were inaccurate to predict Wpeakactual in 82% of the COPD patients. The new Wpeak regression equation differed less between Wpeakestimated and Wpeakactual compared to existing models. Still, in 74% of COPD patients Wpeakestimated and Wpeakactual differed more than (±) 5 watts. Conclusion. In conclusion, estimating peak work load from 6MWD in COPD is inaccurate. We recommend assessment of Wpeak using CPET during pre-rehabilitation assessment in addition to 6MWT.     

Use of the 15-steps climbing exercise oximetry test in patients with idiopathic pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is often associated with exercise-induced hypoxemia. Although maximal oxygen consumption (VO2(max)) is considered the gold-standard index of functional capacity in IPF, its measurement requires sophisticated equipment and trained personnel. The aim of the present study was to investigate the value of the simple 15-steps climbing exercise oximetry test in patients with IPF. The 15-steps climbing test was administered to 51 patients with IPF. Pulmonary function tests (PFTs), cardiopulmonary exercise test (CPET), and the 6-min walk distance (6MWD) test were performed in the same session. Oxygen saturation in the 15-steps climbing test was measured by continuous oximetry, and quantified oxygen desaturation was determined by calculating the area under the curve of oxygen saturation from the beginning of exercise through the lowest desaturation point until recovery to baseline ("desaturation area"). There was a statistically significant correlation between all parameters of the 15-steps climbing test and both VO2(max)) on the CPET (lowest saturation, p=0.002, r=0.43; saturation difference, p=0.02, r=-0.33; recovery time, p=0.02, r=-0.32; and desaturation area, p=0.005, r=-0.39), and carbon dioxide diffusion in the lungs (DLCO) on the PFTs (lowest saturation, p=0.0001, r=0.52; saturation difference, p=0.0002, r=-0.50; recovery time, p=0.0001, r=-0.53; and desaturation area, p=0.0001, r=-0.53). On stepwise linear regression analysis, independent significant predictors of VO2(max) were lowest saturation on the 15-steps test and the 6MWD. We concluded that the 15-steps oximetry test is a simple and accurate bedside tool for the evaluation of functional capacity in patients with IPF.     

Six minute walk test: a simple and useful test to evaluate functional capacity in patients with heart failure

In heart failure survival is closely related to functional capacity. Peak O(2) consumption at cardiopulmonary exercise test (CPET) is considered the gold standard for the evaluation of exercise tolerance. Since >70% of patients with heart failure, usually elderly or with significant comorbidities, are referred to Departments of Internal Medicine where facilities for cardiopulmonary test are rarely available, CPET may be performed in <5% of the patients. Six-minute walk test (6MWT) has been proposed as a simple, inexpensive, reproducible alternative to CPET. The 6MWT reproduces the activity of daily life and this is particularly relevant in elderly patients who usually develop symptoms below their theoretical maximal exercise capacity. Despite some limits 6MWT is attractive for patients referred to Departments of Internal Medicine allowing an objective evaluation of exercise tolerance, a better prognostic evaluation and a guide to evaluate response to medical treatment.     

Six‐minute walk distance and work relationship with incremental treadmill cardiopulmonary exercise test in COPD

Introduction: Cardiopulmonary exercise testing (CPET) is increasingly used to evaluate the overall impact of the illness on patients with chronic obstructive pulmonary disease (COPD). While laboratory tests of exercise performance are costly, the 6‐min walk test (6‐MWT) can be more easily performed. Although the main outcome commonly used in this field test is the distance walked in 6 min (6‐MWD), this measure does not account for differences in body weight. Previous studies showed a good correlation between the work performed during the 6‐MWT with incremental cycling CPET, an exercise modality more associated with quadriceps fatigability and with lower peak oxygen consumption than incremental walking tests. Objective: Evaluate the correlation between the 6‐MWD and its derivative body weight–walking distance product, an estimation of the work performed during the 6‐MWT, with peak from a treadmill CPET. Methods: Thirty COPD patients [forced expiratory volume in 1 s (FEV₁) = 39 ± 13%; peak predicted] performed CPET to the limit of tolerance on a treadmill and 6‐MWT, 48 h apart.6‐MWD and work were correlated to resting and exercise functional variables. Results: The work of walking during the 6‐MWT provided greater associations with peak than observed with 6‐MWD. This was the case for FEV₁, forced vital capacity, inspiratory capacity, lung diffusion capacity for carbon monoxide, peak , carbon dioxide output, minute ventilation and double product (r = 0.57, r = 0.57, r = 0.73, r = 0.7, r = 0.75, r = 0.65, r = 0.51 and r = 0.4, respectively; all P < 0.05). Conclusion: A better association was found between the work estimated from the 6‐MWT and peak achieved during CPET, in this case with a treadmill, than the 6‐MWD alone. Please cite this paper as: Poersch K, Berton DC, Canterle DB, Castilho J, Lopes AL, Martins J, Oliveira AR and Teixeira PJZ. Six‐minute walk distance and work relationship with incremental treadmill cardiopulmonary exercise test in COPD. Clin Respir J 2013; 7: 145–152.