18
5.
Carrying out a measurement
5.1. Before the measurement:
•
Avoid eating, smoking as well as all forms of exertion directly
before the measurement. All these factors influence the mea-
surement result. Try and find time to relax by sitting in an arm-
chair in a quite atmosphere for about ten minutes before the
measurement.
•
Measure always on the same wrist (normally left).
•
Attempt to carry out the measurements regularly at the same
time of day, since the blood-pressure changes during the course
of the day.
5.2. Common sources of error:
Note:
Comparable blood-pressure measurements always re-
quire the same conditions! These are normally always
quiet conditions.
•
All efforts by the patient to support the arm can increase the
blood-pressure. Make sure you are in a comfortable, relaxed po-
sition and do not activate any of the muscles in the measure-
ment arm during the measurement. Use a cushion for support if
necessary.
•
If the wrist artery lies considerably lower (higher) than the
heart, an erroneously higher (lower) blood-pressure will be mea-
sured! (Each 15cm difference in height results in a measure-
ment error of 10mmHg!)
•
A loose cuff causes false measurement values.
•
With repeated measurements, blood accumulates in the respec-
tive arm, which can lead to false results. Correctly executed
blood-pressure measurements should therefore first be re-
IB BP 3BU1-5 VarB 0702.qxd 13.08.2002 8:41 Uhr Seite 18
