Exercise testing

Indications for Exercise Testing
Chief complaint of on exertion
To determine ventilator to work
To determine limitations to work
To determine workloads for developing or adjusting exercise plan or
Purposes

Contraindications
PaO2 < on RA
PaCO2 >
FEV1 <%
Recent
Unstable
2nd or 3rd degree block
ventricular or atrial
Orthopedic problems that impairs activity
Severe Aortic
CHF
HTN
Neurological Disorders
Dissecting
Severe Pulmonary

Normal response to stress Test
Heart rate will linearly with increased workload
Increased heart rate without ECG changes indicates
ST depressions > mm for seconds indicates ischemia
PVCs with exercise are associated with ischemia if > per
If systolic blood pressure rise, cardiac output is not
Respiratory rate, tidal volume and minute volume will during testing
VCO2 and VO2 will rise together to keep RER near
pH will initially but will at anaerobic threshold
VD/VT will because of increased
Pulmonary Artery pressure will remain in normal patients.

Limitations to Exercise testing

Ventilatory Limitations @ low/mod workload:
Maximum minute ventilation = FEV1 x
Ve/VO2 > L/LO2
Respiratory
Increased
Decrease in O2 Sat
PAP
Normal and HR

Limitations to Exercise testing
Cardiac Limitation @ low/mod workload:
Significant Changes
Diastolic Pressure
Systolic Pressure does not
O2 pulse
Vt, RR, Ve is less than % of MMV

Limitations to Exercise testing

Poor Conditioning
Present with HR and low/mod workloads with normal ECG and Vt, RR, Ve <% MMV

Poor Effort
Present when ECG, SaO2 and HR are and anaerobic threshold is achieved and Ve <% MMV

Workload: Amount of being generated by patient during exercise. Measure in kilopond meters (kpm)

Power: Amount of per minute. Measure in . 1 watt = 6.12 kpm/min

Metabolic Equivalents (METS) – Unit that measures O2 per kg of body weight. 1 met = 3.5 mL/O2/kg (normal at rest) VO2 is measured during test and by pt weight in kg, then divided by 3.5 to get METS.

Anaerobic Threshold – Level of exercise or VO2 at which metabolism will begin to supplement aerobic metabolism. Lactic acid increases, pH decreases, HR is stable, Ventilatory equivalent for O2 and CO2 changes.

O2 Max – continues to increase but does not.

Steady State Vs Multistage Testing
Steady State – Pt is exercised at level for 5-8 minutes at 50-% of max load.
(220-age = max HR)
Once that target is reached, timing begins, measurements are made during final - minutes.

Multistage – Workloads are and measurement made at the end of each (increase at 15 watts/min)
<50 watts –
50-100 watts –
>100 watts –
200 watts high for stress testing.
Can be changed every - minutes by increasing , grade, or .

To verify treadmill is at a 10% incline – take a ” carpenter’s level and place on treadmill. The High end should be ” above the low end.
3” Rise / 30” run = 10
Set workload at – watts/min to reach 100 -150 watts in 10 min.

Stress Test without Gas Analysis (Multistage)
Prepare Patient: 12 lead – resting. Hx and physical exam. Informed consent
Equipment: Treadmill, cycle or step
Pt is stressed until HR achieved or pt develops that indicate to stop.
Workload should gradually be and pt monitored until vitals return to

Stress testing with Gas Analysis (Steady State)
Pt is prepared and stressed at maximal level for 5-8 minutes
Expired gas is collected near of each stage and during final – minutes of testing
Collected using: Volume Spirometer, pneumotach, or breath by breath analysis.
Measurement Includes: Exhaled , Temperature, Time of collection, respiratory , O2, CO2
Allows for calculation of: ventilation, Vt, , CO2 Production, Respiratory Exchange , VE/VO2, VE/VCO2

Stress Testing with Gas Analysis and ABG
ABG is performed time as gas analysis
Inability to stabilize arm for is a problem. Arterial line would be
Indicated for patients with primary problems
Additional measurements: Physiologic , , VD/Vt, Output

Bruce Protocol: Workload is increased every minutes.

Borg Scale: Scale of 1 – .

Modified Borg Scale: 1 –

Specific Reasons for ending exercise test
mm elevation in segment
Inverted waves
Presence of large waves
Vtach or
Multifocal
2nd or 3rd degree heart block
Exercise induced right or left bundle branch block
that progresses with testing
Sweating and pallor
Systolic pressure > or diastolic >
Systolic Pressure does not or falls as workload increases
Lightheadedness
Cyanosis
Nausea
Muscle
Hyperventilation

Tidal Volume Loops
Plotted on top of loop
during exercise is used to position the loop on top of loop
Normal response to exercise will demonstrate a decrease in and in order to increase Vt and Ve

Pt with Hypoxemia
Monitor titration with pulse ox
If resting SpO2 is low do O2 titration at before exercise titration

6 Minute Walk test
Pt is to walk as far as possible in minutes
Pt can slow down or rest if needed.
Record Symptoms and SpO2 during stop
Terminate test if significant , mental confusion or SpO2 <%

Safety
Do a HX for , Physical , and