COPD患者6MWT下指脉氧特点及运动耐力相关因素分析

The characteristics and correlative factors of pulse oxygen saturation and exercise tolerance of COPD patients in 6MWT

目的:研究慢性阻塞性肺疾病(chronic obstructive pulmonary disease,COPD)稳定期患者在6 min步行试验(6-minute walk test,6MWT)下脉搏血氧饱和度(pulse oxygen saturation,SpO_(2))和运动耐力的特点及相关因素,为COPD患者提供简便有效的客观评估方法。方法:纳入COPD稳定期患者58例和对照组患者21例,收集一般资料、改良版英国医学研究委员会呼吸困难问卷(modified medical research council dyspnoea scale,mMRC)评分、COPD自我评估测试(COPD assessment test,CAT)评分、肺功能参数(如FEV1%Pred、FVC%Pred、D_(L)CO%Pred、DLCO/VA%Pred)和6MWT相关参数,分析SpO_(2)和运动耐力指标的组间差异及其与COPD常用评估指标的相关性。结果:COPD患者在6MWT出现运动SpO_(2)下降,表现为运动性低氧(exercise-induced de-saturation,EID),最低SpO_(2)(SpO_(2min))和平均SpO_(2)(SpO_(2mean))下降,运动SpO_(2)低于88%、90%、92%的时间百分比(T88、T90、T92)和低氧面积(desaturation area,DA)增加;6 min步行距离占预计值百分比(6MWD%Pred)和低氧距离比(desaturation distance ratio,DDR)在组间有差异;SpO_(2mean)、DA、DDR、6MWD%Pred均分别与mMRC评分、FEV1%Pred、FVC%Pred、静息SpO_(2)(SpO_(2)rest)相关,DDR还与D_(L)CO%Pred、DLCO/VA%Pred相关,但是,多因素线性回归分析显示只有mMRC评分、D_(L)CO%Pred和SpO_(2)rest与DDR独立相关。结论:稳定期COPD患者6MWT同步持续脉搏指脉氧检测,其检测参数SpO_(2mean)、DA、DDR和6MWD%Pred能有效反映COPD患者肺功能和症状,提示该评估方法有效,有助于COPD患者的评估和管理。

Objective:To study the characteristics and correlative factors of pulse oxygen saturation(SpO_(2))and exercise tolerance during the 6-min walk tes(t 6MWT)in the stable chronic obstructive pulmonary disease(COPD)patients,aiming to provide a simple and effective objective assessment method for COPD patients.Methods:A total of 58 stable COPD patients and 21 control subjects were enrolled.General data,modified Medical Research Council dyspnoea scale(mMRC)score,COPD assessment tes(t CAT)score,pulmonary function parameters(such as FEV1%Pred,FVC%Pred,D_(L)CO%Pred,DLCO/VA%Pred),and 6MWT-related parameters were collected.The study analyzed the differences in SpO_(2)and exercise tolerance indicators between groups,and their correlation with commonly used COPD assessment indicators.Results:COPD patients exhibited a decline in exercise SpO_(2)during the 6MWT,characterized by the occurrence of exercise-induced desaturation(EID),a decline in minimum SpO_(2)(SpO_(2min))and mean SpO_(2)(SpO_(2mean)),an increase in the percentage of time with SpO_(2)below 88%,90%,and 92%(T88,T90,T92)and desaturation area(DA).There were differences in the 6-minute walk distance(6 MWD)as a percentage of the predicted value(6MWD%Pred)and the desaturation distance ratio(DDR)between the two groups.SpO_(2mean),DA,DDR and 6MWD%Pred were correlated with mMRC scores,FEV1%Pred,FVC%Pred,and resting SpO_(2)(SpO_(2)rest).DDR was also correlated with D_(L)CO%Pred and DLCO/VA%Pred.However,multivariable linear regression analysis showed that only mMRC scores,D_(L)CO%Pred,and SpO_(2)rest were independently associated with DDR.Conclusion:Continuous SpO_(2)monitoring during the 6MWT,with parameters such as SpO_(2mean),DA,DDR,and 6MWD%Pred,can effectively reflect pulmonary function and symptoms of stable COPD patients,suggesting its efficacy in assessment and management of COPD patients.