Cleveland Family Study
2.7 Blood Pressure Readings
The observer should proceed to carry out the first BP reading. The systolic value (1st phase Korotkoff) can be identified as the pressure level where the first of 2 or more sounds are heard in the appropriate rhythm. The diastolic value (5th phase Korotkoff) can be identified as the pressure level where the last of these rhythmic sounds is heard.
Note: A single sound heard in isolation (i.e., _not in rhythmic sequence_) before the first of the rhythmic sounds (systolic) or following the last of the rhythmic sounds (diastolic) does not meet these criteria for the systolic or diastolic endpoints. _If the sounds are heard all the way to 0 mm Hg, record the 4th phase DBP. The measurement should be recorded as Korotkoff 1/Korotkoff 4/ Korotoff 5 (e.g., 122/60/0 on the physioform in the margin, just to bring it to our attention)._
The American Heart Association (1980) defines the K-sounds as follows. (American Heart Association. Recommendation for Human Blood Pressure Determination by Sphygmomanometer. Dallas, American Heart Association, 1980).
- Phase I: The point marked by the first appearance of faint, clear tapping sounds that gradually increase in intensity.
- Phase IV: The point marked by the distinct, abrupt muffling of sound so that a soft, blowing quality is heard.
- Phase V: The point at which the sound disappears.
2.7.1 Procedure
Once the cuff and device are connected, as required beforehand for determination of the peak inflation level, the steps in measurement are as follows:
- Make sure the participant’s is position appropriately.
- Sitting BP – Taken with participant in chair or on edge of bed with feet and ankles are uncrossed.
- Supine BP – Taken with participant after participant has been in supine position for at least 10 minutes.
- Wait at least 30 seconds after complete deflation of the cuff following any preceding inflation.
- Place the earpieces of the stethoscope, with the tips turned forward, into the ears.
- Apply the bell of the stethoscope over the brachial artery, just between the elbow crease and the lower edge of the cuff, but not touching the cuff or tubing. The brachial artery is usually found at the crease of the arm, slightly toward the body.
- By closing the thumb valve and the squeezing the bulb, inflate the cuff at a rapid but smooth continuous rate to the peak inflation level.
- By opening the thumb valve slightly, and maintaining a constant rate of deflation at approximately 2mm per second, allow the cuff to deflate, listening throughout the entire range of deflation, from the peak inflation pressure past the systolic reading (the pressure where the first regular sound is heard), until 10 mm Hg below the level of the diastolic reading (that is, 10 mm Hg below level where the last regular sound is heard).
- The cuff is then fully deflated by opening the thumb valve, and is disconnected; the stethoscope earpieces are removed from the ears; and the systolic and diastolic readings are entered in the spaces provided on the form.
- The subject’s arm is raised, passively, overhead for 15 seconds. The arm is then lowered gently.
- The BP measurements are repeated exactly as before two more times. The observed SBP and DBP values are recorded on the Nursing Assessment Form (data sheet).
- Remove the cuff and store the equipment safely after the last reading.
2.7.2 Ways to Emphasize Sound
- Rapidly inflate the cuff (standard technique).
- Inflate the cuff while the arm is elevated straight up.
- Open and close the fist several times rapidly after the cuff has been inflated above the systolic level.