1. EHES Training Material
Blood pressure measurement by mercury sphygmomanometer - background information
EHES Training Material

2. Hypertension as a cardiovascular risk factor

3. What is blood pressure?
Systolic blood pressure (higher value), represents the pressure while the heart contracts to pump blood to the body
First appearance of a clear repetitive sounds (Phase I)
Diastolic blood pressure (lower value), represents the pressure when the heart relaxes between beats
Disappearance of the repetitive sounds (Phase V)

4. Risk factors of elevated blood pressure
Salt intake
Obesity
Alcohol use
Sedentary lifestyle
Smoking
Fat contents of the food

5. Factors affecting blood pressure levels
Measurement environment
Noise, temperature
Factors related to the participant
Factors related to the measurer
Measurement device
Cuff size

6. 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

7. Average magnitude of the effects (1/3)
Systolic bp (mmHg)
Diastolic bp (mmHg)
Full bladder
 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
 mmHg
 14 mmHg
Back / feet unsupported
 5-15 mmHg
 6 mmHg
Supine posture instead of sitting posture
 3-10 mmHg
 1-5 mmHg

8. Average magnitude of the effects (2/3)
Systolic bp (mmHg)
Diastolic bp (mmHg)
Legs crossed
 5-8 mmHg
 3-5 mmHg
Participant talks during the measurement
 mmHg
 6-10 mmHg
Arm below heart level
 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

9. Average magnitude of the effects (3/3)
Systolic bp (mmHg)
Diastolic bp (mmHg)
Diaphragm of the stethoscope instead of bell
 2 mmHg
 0-2 mmHg
Cuff too small
 3-12 mmHg
 2-8 mmHg
Cuff too large
 mmHg
Cuff over clothing
 up to 5 mmHg

10. Three categories of observer error
Systematic error that leads to both intra-observer and inter-observer error
Terminal digit preference, which results in the observer rounding of the pressure reading to a digit of his or her choosing, most often to zero
Observer prejudice or bias, whereby the observer adjust the pressure to meet his or her preconceived notion of what the pressure should be
Rose G et al. Lancet 1965; 1: 673-4

11. Acknowledgements
Slides
Hanna Tolonen