ETSU PT Program - PHYT 6541

Blood Pressure Lab

I. The Determination Of The Proper Size Of Blood Pressure Cuff For Your Patient

Take the blood pressure cuff and lay it out flat on the table. With a tape measure, measure the width and length of the air bladder of the cuff in centimeters (cm).

Next, measure the circumference of your group members right arm in centimeters over the biceps brachii muscle midway between the acromion process and the olecranon process. Convert the inches readings into centimeters (cm).

Finally, take the bladder width and divide that number by the arm circumference recording the percentage value on your sheet. Do the same for the cuff bladder length and the arm circumference values and record the values on your sheet. Remember to convert inches to centimeters.

Convertion of inches into centimeters : 1 inch = 2.54 centimeters.

  • Cuff bladder width (cm) :
  • Cuff bladder length (cm) :
  • Patient's arm circumference (cm) :
  • The American Heart Association has recommended that the width of the air bladder inside the cuff equal 40% of the circumference of the limb being measured and that the length of the air bladder be equal to 80% of the arm circumference or two times the recommended width of the air bladder.

    What % values do you come up with for the following calculations ?

    Cuff Bladder Width (cm)
    Arm Circumference (cm) =

    Cuff Bladder Length (cm)
    Arm Circumference (cm) =

    Question : Is your cuff the correct size ?

    Recommendations From The American Heart Association On Cuff Size :

    Cuff Type
    Arm Circumference (cm)
    Bladder Width (cm)
    Bladder Length (cm)
    5.0 - 7.5
    7.5 - 13.0
    13.0 - 20.0
    Small Adult
    17.0 - 26.0
    24.0 - 26.0
    Large Adult
    32.0 - 42.0
    42.0 - 50.0

    Questions :

    1. What would happen to your BP reading if you used a cuff that was too large ?

    2. What would happen to your BP reading if you used a cuff that was too small ?

    II. The Effect Of The Valsalva Manuever On Blood Pressure

    Please work in groups of 3 individuals. Place the blood pressure cuff on the right arm. Find the individual's pulse in the antecubital space. Place the diaphragm firmly over the artery and pump up the cuff to 200 mm Hg. While subject performs the Valsalva manuever in supine, slowly release the cuff pressure and listen for the first Karotkoff sound. This will be the systolic blood pressure. Continue listening to the heart beats until you notice either a complete cessation of beats or a change in the pitch of the beat. This will be the diastolic blood pressure. Record the systolic and the diastolic readings that you hear. Perform this 2-3 times for each person.

    Questions :

    What were your readings ?

    What explanations can you give for your findings ?



    How does blood normally return to the right side of the heart from the periphery ?


    What implications does performing a Valsalva maneuver have for the elderly and those individuals with known cardiovascular disease ?

    III. Take the individuals blood pressure first on the right arm and then on the left arm.

    Questions :

    1. What were your readings ?
    2. Where there any differences side to side ?
    3. Should you note differences in side-to-side BP in the patient's chart ?

    IV. Monitor the blood pressure while walking with your "patient" down the hall.

    Questions :

    1. What were your readings ?
    2. Did you have any difficulty in measuring the blood pressure during dynamic gait ?
    3. How important is it for you to obtain an accurate blood pressure during dynamic exercise ?

    V. Monitor the subject's blood pressure while walking on a treadmill at the end of the following stages : 1) at 2.0 mph at 0% grade for 3 minutes; 2) at 3.0 mph with a 5% grade for 3 minutes; 3) at 3.5 mph at 10% grade for 3 minutes. Record your data.

    If the treadmill is occupied, you can do this section of the lab on a bicycle ergometer. If you use a bicycle ergometer, simply start at a low work at 300 Kpm intensity at 60 rev/min advancing it to 600 Kpm for stage 2 and then to 900 KPM for stage 3. Record the blood pressure and heart rate at the end of each three minute stage before increasing the treadmill speed or bicycle workload. Multiply the heart rate and systolic BP to obtain the "double product" or the "rate-pressure product".

    Questions :

    1. What were your BP and heart rate readings at each of the 3 minute stages ?
    2. Stage I :

      Stage II :

      Stage III :

    3. Why is the rate-pressure product a significant biological parameter for you to monitor in the elderly, frail elderly, in patients with cardiovascular disease or in people who are performing a GXT ?
    4. What were the patient's double product values for each of the three minute stages ?
    5. Stage I :

      Stage II :

      Stage III :

    6. What did you notice about the readings for the double product over the three stages of the treadmill walk ?
    7. If the double product does not change over the various stages, would this have any medical significance ?