What is the proper technique for measuring blood pressure in a patient, particularly those with a history of hypertension or cardiovascular disease?

How to Measure Blood Pressure Properly

Blood pressure should be measured with the patient seated quietly for at least 5 minutes with feet flat on the floor, back supported, arm supported at heart level, using a validated automated device with the correct cuff size, taking at least 2 readings separated by 1-2 minutes, and averaging these readings. 1

Patient Preparation (Critical First Step)

Before any measurement, ensure the following conditions are met:

• Have the patient sit in a chair with feet flat on the floor and back supported for >5 minutes 1
• The patient must avoid caffeine, exercise, and smoking for at least 30 minutes before measurement 1
• Ensure the patient has emptied their bladder 1
• Neither you nor the patient should talk during the rest period or during measurement 1
• Remove all clothing covering the cuff placement location 1

Common pitfall: Measurements taken while the patient sits or lies on an examining table do NOT fulfill proper criteria and will yield inaccurate readings. 1

Equipment and Positioning

Device Selection

• Use only a validated automated oscillometric device that is calibrated periodically 1
• Upper arm cuff devices are strongly preferred over wrist monitors 1
• Wrist monitors are not recommended for routine clinical use due to poor accuracy 1, 2

Cuff Size (Critical for Accuracy)

• The cuff bladder must encircle 80% of the patient's arm circumference 1
• Using a standard cuff on patients with arm circumference ≥30 cm overestimates BP by 6-9/5-7 mmHg 3
• Note if a larger- or smaller-than-normal cuff size is used in the documentation 1

Arm Positioning

• Support the patient's arm (resting on a desk or table) 1
• Position the middle of the cuff on the upper arm at the level of the right atrium (midpoint of the sternum) 1
• For auscultatory technique, either the stethoscope diaphragm or bell may be used 1

Measurement Technique

Initial Visit Protocol

• At the first visit, record BP in both arms 1
• Use the arm that gives the higher reading for all subsequent measurements 1

Taking the Readings

• Separate repeated measurements by 1-2 minutes 1
• For auscultatory method: palpate radial pulse obliteration pressure to estimate systolic BP, then inflate the cuff 20-30 mm Hg above this level 1
• Deflate the cuff at 2 mm Hg per second while listening for Korotkoff sounds 1

Recording Values

• Record systolic BP as the onset of the first Korotkoff sound 1
• Record diastolic BP as the disappearance of all Korotkoff sounds 1
• Round to the nearest even number 1
• Note the time of the most recent BP medication taken before measurements 1

Averaging and Documentation

• Use an average of ≥2 readings obtained on ≥2 occasions to estimate the individual's BP level 1
• Provide patients with their systolic/diastolic readings both verbally and in writing 1

Special Considerations

Automated Unattended Measurements

Unattended and attended automated office BP measurements yield similar results when core recommendations are followed, allowing staff to initiate measurement, leave the room, and return to document readings. 1

Home Blood Pressure Monitoring

When instructing patients on home monitoring:

• Use a validated automatic upper arm device with memory storage 4
• Measure after 5 minutes of seated rest, before medication, food, or vigorous exercise 4
• Record BP for 7 days (5 days minimum) in the morning and evening with 2 readings each time 4
• Average all readings except the first day; home BP ≥135/85 mmHg indicates hypertension 4
• Have patients bring their device to the office to verify technique and accuracy annually 1

Contraindications to Automated Measurement

Oscillometric devices may not work accurately in patients with atrial fibrillation or frequent ectopic beats—verify accuracy against auscultatory method in these patients. 1

Key Pitfalls to Avoid

• Do not measure BP with the patient on an exam table 1
• Do not use wrist monitors for routine clinical practice 1
• Do not use a standard cuff on patients with large arms (≥30 cm circumference) 3
• Do not allow talking during the rest period or measurement 1
• Do not rely on a single reading—always average multiple readings from multiple visits 1