BRUCE PROTOCOL: MEASURE OF FUNCTIONAL CAPACITY OF THE INDIVIDUAL

BRUCE PROTOCOL MEASURES THE EXERCISE CAPACITY OF THE INDIVIDUAL. THIS HELPS IN CALCULATION OF VO2, MO2 AND HEART RATE MAX AND ULTIMATELY MEASURES THE EXERCISE CAPACITY OF THE INDIVIDUAL.

1. functional diagnosis and physiotherapeutic skill

2. Dr. Sachin Chaudhary principal cum professor datta meghe college of physiotherapy, nagpur BRUCE PROTOCOL

3. The bruce protocol is a diagnostic test used in the evaluation of cardiac function, developed by Robert A Bruce Equipment required: treadmill ,stopwatch, 12 leads ECG machine & leads, sticking tapes, clips

4. Pre test: Explain the test procedure to the subject. Perform screening of health risks and obtained informed consent. Prepare forms and record basic information such as age , height, body weight, gender Perform an appropriate warm up ,attach ECG leads if required

5. As exercise progresses , skeletal muscle blood flow is increased O2 extraction increases by as much as threefold Total calculated peripheral resistance decreases Systolic blood pressure, mean arterial pressure and pulse pressure increases Diastolic blood pressure does not change

6. VO2 Total body or ventilatory oxygen uptake-amount of 02 extracted from air as the body performs work Determinants of vo2 -cardiac output -peripheral AV oxygen difference Maximal AV difference is constant 15 to 17ml/dl Vo2-estimate of maximal cardiac output

7. VO2 can be estimated from treadmill speed and grade V02=(MPHX2.68)X[1+(GRADEX1.8)]+3.5 VO2 can be converted to METS by dividing by 3.5

8. MO2 Myocardial oxygen uptake is the amount of oxygen consumed by the heart muscle Determinantes of mo2-Intramyocardial wall tension ,contractility &HR Mo2-estimated by HR and SBP (double product) Exercise-induced angina often occurs at the same mo2 Higher double product-better myocardial perfusion

9. MAXIMUM HEART RATE Maximum heart rate (MHR):220-age MHR decreased in older person Age predicted maximum heart rate is a useful measurement for safety reasons

10. METABOLIC EQUIVALENT Refers to a unit of oxygen uptake in a sitting resting person Common biologic measure of total body work is the oxygen uptake One MET is equated with the resting metabolic rate (3.5 ml of o2/kg/min) MET value achieved from an exercise test is a multiple of the resting metabolic rate

11. METS associated with activity = measured 3.5( both in ml o2/kg/ min) Measured directly ( as oxygen uptake) or estimated from the maximal workload achieved using standardized equation

12. CALCULATION OF METs ON THE TREADMILL METs= speed x [0.1+( Grade x1.8] +3.5/3.5 Calculated automatically by device

13. CLINICALLY SIGNIFICANT METABOLIC EQUIVALENT FOR MAXIMUM EXERCISE 1 MET RESTING 2MET LEVEL WALKING AT 2 MPH 4MET LEVEL WALKING AT 4 MPH <5MET POOR PROGNOSIS: PEAK COST OF BASIC ACTIVITIES OF DAILY LIVING 10 MET PROGNOSIS WITH MEDICAL THERAPY AS GOOD AS CABG 13 MET EXCELLENT PROGNOSIS 18 MET ELITE ENDURANCE ATHLETES 20 MET WORLD CLASS ATHELETS

14. EXERCISE TEST MODALITIES Isometric ,dynamic and a combination of two Isometric exercise-constant muscular contraction without movement Moderate increase in cardiac output and only a small increase in vo2 Dynamic exercise-rhythmic muscular activity resulting in movement

15. EXERCISE PROTOCOLS Dynamic protocols are most frequently used to assess cardiovascular reserve Should include a low intensity- intensity warm up and a recovery or cool down period Optimal for diagnostic and prognostic purposes

16. TREADMILL PROTOCOL Bruce Modified Bruce Noughton and weber Balke

17. TREADMILL PROTOCOL BRUCE MULTISTAGE MAXIMAL TREADMILLPROTOCOL 3 minutes periods to achieve steady state before workload is increased Limitation –relatively large increase in vo2 between stages Modified Bruce protocol- older individuals or those whose exercise capacity is limited Modified by two 3 min warm up stages at 1.7mph 0% grade 1.7mph 5% grade

18. PROCEDURE Exercise is performed on a treadmill if required the leads of ECG are placed on the chest wall. The treadmill is started at 1.7mph and at a gradient or incline at of 10% At three minutes intervals the incline of the treadmill increases by 2% and speed increases The test should be stopped when the subject cannot continue due to fatigue or pain or due to other medical conditions

19. MODIFIED BRUCE PROTOCOL

20. The modified Bruce protocol starts at a lower work load than the standard test and is typically used for elderly or sedentary patients The first two stage of the modified Bruce test are performed at 1.7 mph and 0% grade and 1.7 mph and 5% grade and the third stage corresponds to the first stage of the standard Bruce test protocol

21. QUESTIONS Explain Bruce protocol? Different theoretical basis of protocols for exercise testing? Modified Bruce protocol ?

22. THANK YOU