STRESS TEST AND HEMODYNAMICS Lois Rowland, MS, RRT-NPS, RPFT, FAARC Objective: Prepare NBRC candidate for CRT and WRT Content Outline Perform, evaluate patient response to, interpret results from: Stress testing e.g. ECG, pulse oximetry Hemodynamic assessment 1
STRESS TESTS / EXERCISE TESTING Test Indications DOE, angina, fatigue 2
Test Indications DOE, angina, fatigue Ventilatory limitations to work Cardiovascular limitations to work Test Indications DOE, angina, fatigue Ventilatory limitations to work Cardiovascular limitations to work Conditioning or deconditioning 3
Test Indications DOE, angina, fatigue Ventilatory limitations to work Cardiovascular limitations to work Conditioning or deconditioning Maximum tolerable workload Disability assessment Appropriate levels of supplemental O 2 Outcomes following treatment Test Contraindications These are relative contraindications, case-by-case: MI within 4 weeks Unstable angina 2 nd or 3 rd degree heart block Rapid arrythmias Orthopedic impairment Severe aortic stenosis CHF Uncontrolled HTN Severe pulmonary HTN Dissecting/ventricular aneurysms Limiting neurologic disease Thrombophlebitis or intracardiac thrombi Recent systemic or pulm.embolus Acute pericarditis PaO 2 < 40 mmhg on RA PaCO 2 > 70 mmhg FEV1 < 30% predicted 4
Test Equipment Treadmill Cycle Ergometer Workload measured in METs MET: multiples of the resting O 2 uptake, usu. 3.5 ml/kg Primary Indication Equipment Measurements Test End 6 Minute Walk Test (6MWT) pre- and post-tx evaluation Hallway 100+ ft. distance walked, O 2 setting and how transported (optional SpO 2 ) walk as far as possible X 6 minutes, signs ischemia 5
Primary Indication Equipment Measurements Test End 6 Minute Walk Test (6MWT) pre- and post-tx evaluation Hallway 100+ ft. distance walked, O 2 setting and how transported (optional SpO 2 ), dyspnea score walk as far as possible X 6 minutes, signs ischemia Interpretation: serial, comparative Primary Indication Equipment Cardiac Stress CAD evaluation Treadmill, cycle ergometer, pharmacologic Measurements BP, HR, ECG Test End End protocol, sustained Vtach, signs ischemia 6
Primary Indication Equipment Measurements Test End Cardio- Pulmonary Testing (CPET) Cardiac &/or pulm exercise in/ tolerance Treadmill, cycle ergometer BP, HR, ECG, RR, SpO 2 or ABG, expired gases (O 2, CO 2, volumes) Predetermined HR or VO 2 max, exhaustion, signs ischemia Image courtesy of MEDGRAPHICS CPET (CPX) Collection and analysis: tidal volume, RR, minute ventilation VO 2 : O 2 consumption or O 2 uptake VCO2: CO 2 production AT: anaerobic threshold, when ventilation disproportionately to VO 2 60-70% pred. VO 2 max 7
AT: ventilation increases disproportionately to O 2 uptake Cardiac disease: AT occurs at <40% of VO 2 max Deconditioning: AT occurs at <pred. VO 2 max, no s/s cardiovascular disease VCO 2 Anaerobic Threshold (AT) VO 2 40% VO 2 pred AT: ventilation increases disproportionately to O 2 uptake Ventilatory limitation: AT not met VCO 2 Anaerobic Threshold (AT) not met VO 2 8
Test Interpretation Normal Cardiac Disease Ventilatory Disease Deconditioning VO 2 max 80% pred VEmax < 70% MVV N > 90% MVV N AT 60-70% pred achieved, low VO 2 not achieved achieved, low VO 2 HR 220 age (target usu. 85%) N ECG signs of ischemia none Present &/or chest pain N N SaO 2 or SpO 2 > 90% N N Primary Indication Equipment Measurements Test End bronchial challenge EIB Treadmill, cycle ergometer During: BP, ECG, SpO 2 (optional ABG) Pre & post spirometry 85% pred max HR X 6-8 min. FEV 1 after exercise 1 minute 2 minutes Every 5 minutes 9
Primary Indication Equipment Measurements Test End bronchial challenge EIB Treadmill, cycle ergometer During: BP, ECG, SpO 2 (optional ABG) Pre & post spirometry 85% pred max HR X 6-8 min. FEV 1 after exercise 1 minute 2 minutes Every 5 minutes Interpretation: 10-15% from pre-exercise FEV1: airway hyperreactivity Primary Indication Measurements Interpretive value 6 Minute Walk Test (6MWT) pre- and post-tx evaluation distance walked, O 2 setting and how transported (optional SpO 2 ), dyspnea score comparative Cardiac Stress CAD evaluation BP, HR, ECG presence or severity of CAD Cardio- Pulmonary Testing (CPET) Cardiac &/or pulm exercise in/ tolerance BP, HR, ECG, RR, SpO 2 or ABG, expired gases (O 2, CO 2, volumes) Differential dx of cardiac and/or pulmonary conditions; evaluate exercise tolerance, endurance bronchial challenge EIB During: BP, ECG, SpO 2 (optional ABG) Pre & post spirometry Presence or severity of airway hyperreactivity, responsiveness to bronchodilator therapy 10
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References American Thoracic Society/American College of Chest Physicians. ATS/ACCP Statement on cardiopulmonary exercise testing. Am J Respir Crit Care Med 2003; 167: 211-277. American Thoracic Society. ATS Statement: Guidelines for the six-minute walk test. Am J Respir Crit Care Med 2002; 166: 111-117. Pilbeam, S. P., & Cairo, J. M. (2006). Mechanical ventilation: Physiologic and clinical applications. (4th ed.). St. Louis, MO: Mosby Elsevier. Ruppel, G. (2003). Manual of pulmonary function testing. (8th ed.). St. Louis, MO: Elsevier Saunders. Wilkins, R. L., Stoller, J. K., & Kacmarek, R. M. (2009). Egan's fundamentals of respiratory care. (9th ed.). St. Louis, MO: Mosby Elsevier. 19