CPET心肺运动试验培训课件_002

CPET心肺运心肺运动试验动试验OutlineDescription of CPETWho should and who should not get CPETWhen to terminate CPETExercise physiologyDefine terms:respiratory exchange ratio,ventilatory equivalent,heart rate reserve,breathing reserve,oxygen pulsePattern of CPET results COPD vs CHFRationale for Exercise TestingCardiopulmonary measurements obtained at rest may not estimate functional capacity reliablyClinical Exercise Tests6-min walk testSubmaximalShuttle walk testIncremental,maximal,symptom-limitedExercise bronchoprovocationExertional oximetryCardiac stress testCPETKarlman WassermanCoupling of External Ventilation and Cellular MetabolismAdaptations of Wassermans GearsGeneral Mechanisms of Exercise LimitationPulmonaryVentilatoryRespiratory muscle dysfunctionImpaired gas exchangeCardiovascularReduced stroke volumeAbnormal HR responseCirculatory abnormalityBlood abnormalityPeripheralInactivityAtrophyNeuromuscular dysfunctionReduced oxidative capacity of skeletal muscleMalnutritionPerceptualMotivationalEnvironmentalWhat is CPET?Symptom-limited exercise testMeasure airflow,SpO2,and expired oxygen and carbon dioxideAllows calculation of peak oxygen consumption,anaerobic thresholdComponents of Integrated CPETSymptom-limitedECGHRMeasure expired gasOxygen consumptionCO2 productionMinute ventilationSpO2 or PO2 Perceptual responsesBreathlessnessLeg discomfortModified Borg CR-10 ScaleIndications for CPETEvaluation of dyspneaDistinguish cardiac vs pulmonary vs peripheral limitation vs otherDetection of exercise-induced bronchoconstrictionDetection of exertional desaturationPulmonary rehabilitationExercise intensity/prescriptionResponse to participationPre-op evaluation and risk stratificationPrognostication of life expectancyDisability determinationFitness evaluationDiagnosisAssess response to therapyMortality in CF PatientsNixon et al;NEJM 327:1785;1992.Followed 109 patients with CF for 8 yrs from CPETPeak VO2 81%predicted:83%survivalPeak VO2 59-81%predicted:51%survivalPeak VO2 14 ml/kg/min:1-yr survival 94%2-yr survival 84%Peak VO2 14 ml/kg/min:1-yr survival 47%2-yr survival 32%CPET to Predict Risk of Lung Resection in Lung CancerLim et al;Thorax 65:iii1,2010Alberts et al;Chest 132:1s,2007Balady et al;Circulation 122:191,2010Peak VO2 15 ml/kg/minNo significant increased risk of complications or deathPeak VO2 15 ml/kg/minIncreased risk of complications and deathPeak VO2 10 ml/kg/min40-50%mortalityConsider non-surgical management Absolute Contraindications to CPETAcute MIUnstable anginaUnstable arrhythmiaAcute endocarditis,myocarditis,pericarditisSyncopeSevere,symptomatic ASUncontrolled CHFAcute PE,DVTRespiratory failureUncontrolled asthmaSpO2 200/120)Significant pulmonary HTNTachyarrhythmia,bradyarrhythmiaHigh degree AV blockHypertrophic cardiomyopathyElectrolyte abnormalityModerate stenotic valvular heart diseaseAdvanced or complicated pregnancyOrthopedic impairmentIndications for Early Exercise TerminationPatient requestIschemic ECG changes2 mm ST depressionChest pain suggestive of ischemiaSignificant ectopy2nd or 3rd degree heart blockBpsys 240-250,Bpdias 110-120Fall in BPsys 20 mmHgSpO2 1(CO2 production O2 consumption).Carbon dioxide regulates ventilation.Ventilation will disproportionately increase at lactate threshold to eliminate excess CO2.Increase in ventilatory equivalent for oxygen demarcates the anaerobic threshold.Lactate ThresholdDetermination of AT from RER Plot(V Slope Method)Determination of AT from Ventilatory Equivalent PlotWasserman 9-Panel PlotOxygen Consumption:Fick EquationFick Equation:Q=VO2/C(a-v)O2VO2=Q x C(a-v)O2VO2=SV x HR x C(a-v)O2Heart diseaseHeart diseaseLung diseaseMuscle diseaseDeconditioningAnemiaLung disease(low SaO2)Arterial oxygen content=(1.34)(SaO2)(Hgb)Venous oxygen content=(1.34)(SvO2)(Hgb)Oxygen PulseOxygen Pulse:“.the amount of oxygen consumed by the body from the blood of one systolic discharge of the heart.”Henderson and PrinceAm J Physiol 35:106,1914Oxygen Pulse=VO2/HRFick Equation:VO2=SV x HR x C(a-v)O2VO2/HR=SV x C(a-v)O2 Oxygen Pulse SVInterpretation of CPETPeak oxygen consumptionPeak HRPeak workPeak ventilationAnaerobic thresholdHeart rate reserveBreathing reserveHeart Rate ReserveComparison of actual peak HR and predicted peak HR=(1 Actual/Predicted)x 100%Normal 30%Comparison CPET results Normal CHF COPDPredicted Peak HR150150150Peak HR150140120MVV10010050Peak VO22.01.21.2AT1.00.61.0Peak VE604049Breathing Reserve40%60%2%HR Reserve0%7%20%Borg Breathlessness548Borg Leg Discomfort885Cardiac vs Pulmonary LimitationHeart DiseaseBreathing reserve 30%Heart rate reserve 15%Pulmonary DiseaseBreathing reserve 15%CPET Interpretation Peak VO2 HRR BR AT/VO2max A-aNormal 80%30%40%normalHeart disease 80%30%40%normalPulm vasc dis 80%30%40%increasedPulm mech dis 15%40%increasedDeconditioning 15%30%40%normalSUMMARYCardiopulmonary measurements obtained at rest may not estimate functional capacity reliably.CPET includes the measurement of expired oxygen and carbon dioxide.The Borg scale is a validated instrument for measurement of perceptual responses.CPET may assist in pre-op evaluation and risk stratification,prognostication of life expectancy,and disability determination.SUMMARYCycle ergometer permits direct power calculation.Peak VO2 is higher on treadmill than cycle ergometer.Peak VO2 may be lower than VO2max.Absolute contraindications to CPET include unstable cardiac disease and SpO2 20 mmHg is an indication to terminate CPET.1 glucose yields 36 ATP in slow twitch fiber,and 2 ATP+2 lactic acid in fast twitch fiber.RER=CO2 produced/O2 consumedSUMMARYAbove the anaerobic threshold,CO2 production exceeds O2 consumption.Ventilation will disproportionately increase at lactate threshold to eliminate excess CO2.AT may be determined graphically from V slope method or from ventilatory equivalent for CO2.Derived from the Fick equation,Oxygen Pulse=VO2/HR,and is proportional to stroke volume.In pure heart disease,BR is 30%and HRR 15%.In pure pulmonary disease,BR is 15%.