Essential Hypertension: Diagnosis [Clinical Review Discussion]

Establishing a diagnosis of hypertension (HT) or pre-hypertension (PHT) would seem to be a relatively straight forward task.  Although it is easy to take a blood pressure and check a chart, the measurement of blood pressure itself is fraught with potential for significant error.  Both under measurement and over measurement can expose the patient to unnecessary risk.  An accurately measured blood pressure is essential to best serve the patient (1).  The following synopsis comes from the National Guidelines Clearinghouse (2)

The reader is encouraged to visit this site for a more comprehensive overview. 

Proper protocols for measurement of blood pressure:

1.  All monitors should be tested for accuracy
 
2.  Patient should remove all clothing that covers the location of cuff placement.
 
3.  The patient should be comfortably seated, with legs uncrossed and the back and arm supported.  The middle of the cuff is placed at the level of the right atrium.
 
4.  At the initial visit blood pressure should be taken in both arms.
 
5.  The measurement should be taken 5 minutes after the patient sits down for the measurement.
 
6.  The cuff size should be proper for the size of the patient.

• For arm circumference of 22 to 26 cm, the cuff should be "small adult" size: 12X22 cm
• For arm circumference of 27 to 34 cm, the cuff should be "adult" size: 16X30 cm
• For arm circumference of 35 to 44 cm, the cuff should be "large adult" size: 16X36 cm
• For arm circumference of 45 to 52 cm, the cuff should be "adult thigh" size: 16X42 cm

7.  Two readings should be taken 1 minute apart and the readings averaged.  If there is greater than 5 mm difference between the readings additional readings (1 or 2) should be taken and averaged.

Failure to comply with these procedures can result in significant error in measurement according to the National Clearinghouse.