Blood pressure measurement by

automated devices- background information

EHES Training Material

Hypertension as a cardiovascular risk factor

What is blood pressure?

• Systolic blood pressure (higher value) represents the pressure while the heart contracts to pump blood to the body

• Diastolic blood pressure (lower value) represents the pressure when the heart relaxes between beats

Risk factors of elevated blood pressure

• Salt intake• Obesity• Alcohol use• Sedentary lifestyle• Smoking• Fat contents of the food

Factors affecting blood pressure levels

• Measurement environment • Noise, temperature

• Factors related to the participant• Factors related to the measurer• Measurement device

• Cuff size

Factors related to the participant

• Emotions – white coat hypertension• Exercise• Eating before measurement• Smoking• Use of caffeine containing drinks• Alcohol use• Full bladder• Pain• Daily variation• Medication

Average magnitude of the effects (1/3)

Effect Systolic bp (mmHg) Diastolic bp (mmHg)

Full bladder 10-15 mmHg, even up to 50 mmHg if bladder uncomfortably distended

10 mmHg, even up to 40 mmHg if bladder uncomfortably distended

Not resting 3 to 5 minutes before measurement

10-20 mmHg 14 mmHg

Back / feet unsupported

5-15 mmHg 6 mmHg

Supine posture instead of sitting posture

3-10 mmHg 1-5 mmHg

Average magnitude of the effects (2/3)

Effect Systolic bp (mmHg) Diastolic bp (mmHg)

Legs crossed 5-8 mmHg 3-5 mmHg

Participant talks during the measurement

10-15 mmHg 6-10 mmHg

Arm below heart level

10 mmHg 10 mmHg

Physical exercise before measurement

22 mmHg 7-8 mmHg

Left arm instead of right arm

1-3 mmHg 1 mmHg

Arm unsupported during the measurement

1-7 mmHg 5-11 mmHg

Average magnitude of the effects (3/3)

Effect Systolic bp (mmHg) Diastolic bp (mmHg)

Cuff too small 3-12 mmHg 2-8 mmHg

Cuff too large 10-30 mmHg 10-30 mmHg

Cuff over clothing up to 5 mmHg

Acknowledgements

• Slides• Hanna Tolonen