AHA Issues Scientific Statement on Accurate Blood Pressure Readings

Body Position and BP Measurement

• Compared with the seated position, systolic BP (SBP) may be 3-10 mm Hg higher in the supine position
• Compared with the seated position, diastolic BP (DBP) may be 1-5 mm Hg higher in the supine position
• If the patient is in the supine position with their arm resting on the bed, their arm is below heart level
• The cuffed arm should be supported with a pillow if BP is measured for a patient in the supine position
• The right atrium level is the midpoint of the sternum or the 4^th intercostal space in the seated position
• SBP and DBP may increase by 5-15 and 6 mm Hg, respectively, if the patient’s back is not supported
• If a patient’s legs are crossed, this may raise SBP by 5-8 mm Hg and DBP by 3-5 mm Hg
• Readings will be too high if the upper arm is below the level of the right atrium

Proper Seated BP Measurement in the Office

• Step 1: Properly prepare the patient
  • The patient should relax and sit in a chair with feet flat on the floor and back supported. They should be seated for 3-5 minutes without talking or moving before recording the first BP measurement
  • The patient should avoid caffeine, exercise, and smoking for ≥ 30 minutes before measurement
  • The patient should empty their bladder before measurement.
  • Neither the patient or clinician should talk during the rest period or during measurement
  • Remove clothing covering the location of cuff placement.

• Step 2: Use proper techniques
  • Use a validated, calibrated upper-arm cuff BP measurement device.
  • Support the patient’s arm
  • Position the middle of the cuff on the patient’s upper arm at the level of the right atrium
  • Use the correct cuff size so that the bladder encircles 75%-100% of the arm
  • Use the stethoscope diaphragm or bell for auscultatory readings

• Step 3: Take the proper measurements needed for diagnosis and treatment of elevated BP/hypertension
  • On the first visit, record BP in both arms. Then use the arm that gives the higher initial reading for subsequent readings
  • Wait 1-2 minutes between repeated measurements
  • For auscultatory determinations, use a palpated estimate of radial pulse obliteration pressure to estimate SBP. Inflate the cuff 20-30 mm Hg above that level for an auscultatory determination of BP
  • Deflate the cuff pressure 2 mm Hg/s and listen for Korotkoff sounds for an auscultatory reading

• Step 4: Properly document accurate BP readings
  • Record SBP and DBP to the nearest even number
  • Note the time that the patient had most recently taken BP medication before the reading

• Step 5: Average the readings
  • Use an average of ≥2 readings from ≥2 occasions.

• Step 6: Provide BP readings to patient
  • Provide SBP/DBP readings both verbally and in writing, and help the patient interpret the results

This article originally appeared on The Cardiology Advisor