Cardiopulmonary Exercise Test To Assess The Severity Of The Chronic Obstructive Emphysema

Background:Chronic obstructive pulmonary disease (COPD) is divided into two kinds of phenotypic, chronic bronchitis and emphysema, chronic bronchitis model is mainly due to the inherent airway stenosis caused by;emphysema is due to pulmonary emphysema type elastic retraction force weakened or lost.In clinic we often encounter by high resolution CT scanning has obvious emphysema and pulmonary nonemphysema patients have the same static FEV1value this kind of cases, and some will appear normal lung function in patients with severe emphysema. Emphysema forced expiratory when motion the elasticity of the medium and small airway retraction force decrease and small airway collapse, making high FEV1values assessed the degree of airflow is limited.Traditional methods for the assessment of emphysema is through the static lung function in the RV/TLC to diagnose the severity of emphysema and evaluation of emphysema.Emphysema is a pathological definition, with the continuous development of CT technology, especially the emergence of high-resolution computed tomography (CT) in spatial resolution to improve performance, can show similar to the pathologic specimens or slice of anatomical structures.Application of high resolution CT study emphysema also gradually become the research hot spot.Main methods are that using high resolution CT of emphysema patients at the end of deep inspiration and deep breath at the end of the whole lung scanning, through image reconstruction, recognition and quantitative lung low attenuation area (at the end of deep inspiration below-950HU, deep breath at the end of the below-910HU) to assess the existence of emphysema and through lung volume index, mean lung density value, pixel index, the index of voxel index to evaluate the severity of emphysema or emphysema.Cardiopulmonary exercise test (CPET) or exercise Cardiopulmonary function test is refers to the determination of aerobic exercise test, is a comprehensive assessment of heart and lung, and under a certain power load is to measure oxygen uptake and metabolism indexes such as carbon dioxide discharge amount, ventilation index and electrocardiogram (ECG) changes. CPET is to evaluate cardiovascular system and respiratory system’s response to the same stress situation by measuring gas exchange. At the same time in the determination of gas exchange, it also evaluated the patients in the exercise ECG, heart rate and blood pressure change, and the recovery after exercise blood pressure and heart rate. It is important to cardiovascular and gas exchange was conducted at the same time and related. This relationship can be reaction of gas exchange dimension, because the determination results is related to the actual energy consumption when motion, not just rely on indirect estimation of energy consumption. CPET also can be used to measure cardiac every output when specific movement power provided by the amount of oxygen and heart beat when motion reaction conditions.Gradually in recent years, the cardiopulmonary exercise testing was used to determine the specific organs of the limit of gas transportation system, thus to further track Movement limited ventilation function of lung diseases, in particular, sports limited ventilation function is defined as the extreme sports in1994when the breathing reserve significantly reduced or run out, the most representative of chronic lung disease is chronic obstructive pulmonary disease (COPD).In recent years research for CPET in COPD show mainly in the following two aspects:first, it is mainly used for exercise tolerance of COPD assessment to the severity of COPD;Second, COPD of different phenotype show different exercise tolerance.For the use of cardiopulmonary exercise testing to assess emphysema is only confined to the relationship between V02max and emphysema,and no studies use other cardio parameters to evaluate the severity of emphysema, especially these indicators affected by gas trap in movement time:Such as VTmax/FEV1;reaction ventilation efficiency△VE/A VCO2and VE/VCO2max,PETCO2.Oxygen uptake efficiency is more and more attention in recent years.The oxygen uptake efficiency is reflecting the oxygen uptake and minute ventilation relationship of an index, oxygen uptake efficiency platform refers to the slope of oxygen uptake efficiency near the anaerobic threshold no longer increases, the emergence of a platform. Foreign scholar’s research indicated that the slope of oxygen uptake efficiency and the oxygen uptake efficiency platform is cardiopulmonary reserve a good indicator of an assessment, and confirmed that the oxygen uptake efficiency platform and the severity and prognosis of heart failure have strong correlation. It has been reported for oxygen uptake efficiency and the correlation of chronic obstructive pulmonary disease movement endurance by Sun Xingguo team, and confirmed that it is closely relative to oxygen uptake efficiency and exercise tolerance;emphysema negative correlation with the severity of the exercise tolerance.so we speculated that the severity of emphysema and oxygen uptake efficiency is related, but for the correlation of the severity of emphysema and oxygen uptake efficiency has not been reported. Objective:Firstly,it is to investigate the safety of cardiopulmonary exercise testing in chronic obstructive pulmonary emphysema. Sencondly,it is for searching for cardio parameters related to the severity of emphysema.Thirdly, it is to research the relationship between the severity of emphysema and hese indicators.Methods:Subjects:Cases selected group of patients in June2012to July2013in guangdong province people’s hospital of respiratory medicine clinic on the stability of COPD patients, all patients were in line with the2011GOLD guide criteria for the diagnosis of COPD. Normal group is derived from the normal people in guangdong province people’s hospital of respiratory medicine clinics,and,patients with pulmonary peripheral benign nodules in the thoracic surgery and pulmonary medicine from June2012to July2013. Inclusion criteria:(1) Cases patients in the diagnosis of COPD in2011GOLD guidance standards.(2) Normal group patients all conform to the conditions that physical examination is normal, in preoperative evaluation in addition to the small peripheral pulmonary nodules, the rest of the index is normal.(3) Sign the informed consent.(4) And tolerance can be fully compatible with the static lung function and patients with cardiopulmonary exercise test. Exclusion criteria:(1) Can’t cooperate with static lung function and except the patients with cardiopulmonary exercise test.(2) The patients is ruled out the research who is with heart failure, anemia, uncontrolled high blood pressure (systolic blood pressure is greater than200mmHg, diastolic pressure is greater than100mmHg), diabetes, coronary heart disease, aneurysms, neuromuscular disease, mental patients with severe mental illness and thyroid function hyperfunction.(3) The patients is ruled out the research if seizures need continuous treatment with drugs.(4) The patients is ruled out the research if nearly four weeks the patients have big haemoptysis.(5) The patients is ruled out the research if patients is with severe anemia.(6) Is set by the American thoracic society contraindications of cardiopulmonary exercise test (acute myocardial infarction, unstable angina, uncontrolled arrhythmia, limited movement of bone disease in patients with and without oxygen blood oxygen saturation below85%) except.(7) The patients is ruled out the research if the test is be early termination, in the exercise test, because chest tightness, high blood pressure (systolic blood pressure is greater than220mmHg or diastolic blood pressure greater than110mmHg), dizziness, limb weakness, and the patients do not meet the anaerobic threshold.(8) The patients is ruled out the research if people don’t agree. In order to evaluate the experimental lung function in patients with damage and screening of normal control group, all patients were all needs to do the following check. The determination of static lung function parameters:Using lung function test that maded in the company called MasterScreen, before accurate recording participants’height, weight, age, gender, with reference to the ATS/ERS lung function instrument quality control standards, is todetermine the static lung function parameters.①A breath method is used to determination of pulmonary ventilation function.②The determination of pulmonary ventilation function:the amount of dispersion of carbon monoxide diffusion at a stretch.③Body tracing box method is used to determine the residual gas and lung volume. Record the following parameters:The first second forced expiratory volume (FEV1), The percentage of the first second forced expiratory volume over expected value (FEV1%), forced vital capacity(FVC), The percentage of forced vital capacity over expected value(FVC%), FEV1over FVC(FEV1/FVC),50%VC, suction flow rate ratio (MEF50/MIF50). Amount of dispersion (DLCO), deep inspiratory capacity(IC), residual capacity(RV) and lung volume(TLC)and the percentage of residual capacity and lung volume over their expected value. Exercise cardiopulmonary function parameter determination:Using Exercise cardiopulmonary function that maded in the company called MasterScreen, we choose to take seat treadmill exercise and1minute stepwise increasing power movement scheme. Every morning to calibration, including capacity, flow rate and gas calibration.①Inform patients of the possible risk exercise cardiopulmonary test.②Before exercise collection and arterial blood gas analysis:is the radial artery.③Wasserman incremental scheme adopted by increasing power. Specific as follows:according to the patient’s height, weight, age at the time of peace movement (physiological load of exercise and movement) and static lung function is to select the increasing power per minute. Through the weight estimate no-load oxygen uptake(the no-load oxygen uptake per minute (ml/min))=150+6xweight (Kg). Estimate the peak oxygen uptake by age and height(Peak oxygen uptake per minute(ml/min)=(height-age)x20(Non-manual men); Peak oxygen uptake per minute (ml/min)=(height-age)×14(Non-manual women), Finally we will be calculate peak oxygen uptake increment per minute in10minutes that is expected to(the increasing power per minute(W)=(Peak oxygen uptake per minute(ml/min)-the no-load oxygen uptake per minute (ml/min))/100). According to patients’movement and static lung function, on the basis of the increasing power per minute, it is appropriate to increase or decrease1/2or2/3.④Clean patients chest and back wall of the skin, connect twelve ECG lead when patients seat, wear the mask which is tightness and not leak, and instruct patients on shoe covers.⑤Request patients to be on the treadmill, adjust the height of the seat and the armrest, let the patient in a comfortable state, connect the blood pressure cuff and the blood oxygen monitor.⑥Began to determine:resting for3minutes, warming up for3minutes in0W, according to given power stepwise increasing power patients start to (maintain speed60rpm) be treadmill. Oral encourage patients to try their best to exercise in the test. If patients can’t maintain speed, bosom frowsty, the area before the heart pain, dizziness, weakness of lower limbs, severe arrhythmia, ECG ST segment down more than2mm, systolic blood pressure been greater than220mmHg, or end diastolic blood pressure been greater than110mmHg instant test.⑦After treadmill stepping on the collection arterial blood gas again, the above method as follows, and then let the patients be res at least30minutes,if he or she is without discomfort,they can be back to the ward or left the hospital.⑧Anaerobic threshold manually adjust:according to the anaerobic threshold V-slope method.⑨Record the following parameters:maximum oxygen uptake (V02max,ml/min), the most powerful (Wmax, W), the biggest breathing rate(BF, times/min), the largest per minute ventilation(VEmax, L/min), the biggest movement when carbon dioxide equivalent of ventilation(VE/VcO2max), at the end of the biggest sports moisture CO2partial pressure(PETCO2max), The slope of VE over VCO2from unloaded pedalling to peak exercise(△VE/△VCO2),the tide volume(VTmax, L), the biggest sports artery CO2partial pressure(PaCO2max, mmHg), Respiratory reserve (BR) is equal to the ratio the FEV1multiplied by the40over the biggest movement of VE, Die cavity quantity (VD/VT).And calculate the follow as:△IC=IC at the biggest sports-IC at rest,△VT/IC=VT/IC at the biggest sports-VT/IC at rest, APaCO2=PaCO2at the biggest sports-PaCO2at rest, AVD/VT=VD/VT at the biggest sports-VD/VT at rest,the oxygen uptake efficiency:according to the following formula:Oxygen uptake=the slope of oxygen uptake efficiency(OUES) multiplied by the1gVE+b,b is the constant. Oxygen uptake efficiency platform(OUEP)=VO2/VE is an average in the vicinity of a plateau at AT. oxygen uptake efficiency at AT=the average of VO2/VE within60s before anaerobic threshold. High resolution CT examination:Using Philips offerings64row CT scanners, patients must go through breathing exercises before the inspection, learning at the end of the suction breathless. Set the scan parameters:Tube voltage:120kv, effective tube current:250mas, scanning collimating:128x0.625, the rotation time:0.5s, pitch:0.915, bed speed:146.4mm/s, layer thickness:1mm, once interval:1mm. The specific methods is as follows. The supine position, use the lift on the arms, the from head to foot scanning, at the end of a patients breathe in the lungs, pointed to the end of the lungs from the whole lung scan. Patients will scan data to the post-processing workstation (Extended offerings workspace TM. The PHILIPS) and set the parameters of CT value is less than the area of-950hu to emphysema area, window width50HZ, a window-975HZ. To organize the pixel emphysema brighten up, and then volume representation technology (UR) to remove the surrounding tissue, trachea, esophagus, lung blood vessels, such as record total lung volume and total volume of emphysema, and calculate the emphysema index El=total volume/total pulmonary emphysema volume. Statistical analysis method:all data be processed using SPSS13.0software.Measurement data is said as mean±standard deviation, count data is said as using several (rate);For normal distribution and variance together with the measurement data with group t test, non-normal distribution or (and) variance of data, by using two independent samples to compare the t test of approximate Satterthwaite;Comparison of three groups of measuring data using the single factor analysis of variance (One-Way ANOVA);Rate or forming than comparison using chi-square test;Correlation analysis using bivariate correlation analysis, if it is a double variable normal distribution data, selects the product moment correlation coefficient (Pearson correlation coefficient), if is a bivariate normal distribution data choose Kendall correlation coefficient or rank correlation coefficient (Spearman correlation coefficient).P<0.05(double side) said the difference was statistically significant.Results:According to the inclusion criteria and exclusion criteria included in120patients, including normal group of36people,84cases (EI)>50%:48人, EI≦50%group:36人). All patients with cardiopulmonary exercise testing can be performed very smoothly.The main reason for the patients in the normal group terminated testing is that patients with lower limb weakness can’t meet the requirements of speed.The main reason for the termination of test group cases is difficult to breathe,especially in EI>50%group.There is a patient to be died.In EI>50%group,there is a patient after motion due to breathing difficulties, blood oxygen saturation below83%to stop exercise,but after rescuing patients blood oxygen saturation can be up to94%.①Cases in the group,44.0%of the patients with VTmax/FEV1is greater than1, EI≦50%in the group with one person VTmax/FEV1is greater than1, in EI>50%groups,100%of patients VTmax/FEV1is greater than1.Through the compare of normal control group, EI≦50%group and El>50%,there are relations beween V02max, VTmax/FEV1,△VE/A VCO2, VE/VCO2max, PETCO2max and oxygen uptake efficiency and the severity of emphysema.③Emphysema severity and the relationship between above index:El and V02max negative correlation (r=0.422, p=0.025).EI and VTmax/FEV1into positive correlation (r=0.668, p=0.0001).EI and VE/VCO2max negative correlation (r=0.54, p=0.003).EI and△VE/△VCO2negative correlation (r=0.565, p=0.002).EI and PETCO2max into positive correlation (r=0.545, p=0.003).EI and OUES negative correlation (r=0.413, p=0.032), El and OUEP negative correlation (r=0.482, p=0.01), EI and OUES@AT negative correlation (r=0.491, p=0.008).To Enter method (forced into law, namely ordinary regression analysis, all the selected independent variables into the equation.)Straight line is adopted to establish the regression equation is as follows: EI=75.315+12.102VTmax/FEV1-0.323VO2max-0.440VE/Vco2max-0.298△VE/△VCo2+0.837PETCO2max-4.638OUES-1.210OUEP-0.470OUES@AT.(deter mination coefficient R2=0.797), the equation to F=4.147, P=0.005).By the regression coefficient of the visible cardio parameter’s influence on the index of emphysema have big to small is:VTmax/FEV1,△VE/△VCO2, VE/VCO2max, V02max, PETCO2max, OUES@AT, OUEP, OUES.Conclusion:Firstly,for patients with COPD, cardiopulmonary exercise testing is a safe means of checking.Sencondly,cardio parameters associated with chronic obstructive pulmonary disease in the indicators are:the VO2max, VTmax/FEV1, VE/VCO2max,△VE/A VCO2, PETCO2max, oxygen uptake efficiency. Thirdly,the VO2max, VTmax/FEV1, VE/VCO2max,△VE/A VCO2, PETCO2max, oxygen uptake efficiency can be used as a predictor of severity of emphysema.