First of all we must use a properly calibrated machine. (Mercury column spectrophotometer)
Step 1
The blood pressure is taken in the (right) arm with the patient relaxed and comfortable.
Step 2
The spectrophotometer cuff is wrapped around the upper arm with the inflation bag placed over the brachial artery.
Step 3
The cuff is inflated until the pressure exceeds the arterial pressure when the radial pulse is no longer palpable.
Step 4
The diaphragm of the stethoscope is positioned over the brachial artery just below th cuff.
Step 5
The cuff pressure is slowly reduced until sounds (Korotkoff sounds) can be heard (phase1). This is the Systolic pressure.
Step 6
The pressure is allowed to fall further until the Korotkoff sounds become suddenly muffled (phase 4)
Step 7
The pressure is allowed to fall still further until they disappear (phase5)
More details - http://www.sumanasinc.com/webcontent/animations/content/bloodpressure.html
Reference - Clinical medicine, Kumar and clark's, 7th edition, page 691
Step 1
The blood pressure is taken in the (right) arm with the patient relaxed and comfortable.
Step 2
The spectrophotometer cuff is wrapped around the upper arm with the inflation bag placed over the brachial artery.
Step 3
The cuff is inflated until the pressure exceeds the arterial pressure when the radial pulse is no longer palpable.
Step 4
The diaphragm of the stethoscope is positioned over the brachial artery just below th cuff.
Step 5
The cuff pressure is slowly reduced until sounds (Korotkoff sounds) can be heard (phase1). This is the Systolic pressure.
Step 6
The pressure is allowed to fall further until the Korotkoff sounds become suddenly muffled (phase 4)
Step 7
The pressure is allowed to fall still further until they disappear (phase5)
The diastolic pressure is usually taken as phase 5 because this phase is more reproducible and nearer to the intramuscular diastolic pressure. The Korotkoff sounds may disappear (phase2) and reappear (phase3) between the systolic and diastolic pressures. Do not mistake phase 2 for the diastolic pressure or phase 3 for the systolic pressure.
More details - http://www.sumanasinc.com/webcontent/animations/content/bloodpressure.html
Reference - Clinical medicine, Kumar and clark's, 7th edition, page 691
