If you have any doubt about the reading accuracy, check the patient's vital signs first before checking
the Monitor's functions.
When unexpected values are measured, check the potential causes, such as
- the incorrect cuff size was used or the cuff is not placed at heart level.
- excessive patient movement.
- measurement over-range.
12.3 Measurement Restrictions
The oscillometric method has some restrictions depending on the patient’s condition. The oscillometric method
detects the regular pulse wave generated by arterial pressure. If the patient’s condition makes it difficult to detect
such waves, the measured value is unreliable, and the cuff inflation time increases. In the following cases, the NIBP
measurement is impossible:
1) Patient Movement
If the patient is moving, trembling or under cramps, which may affect the detection of arterial pressure pulse, the
NIBP measurement is unreliable or impossible and the pressure measurement time will increase.
2) Arrhythmia
If the patient has irregular heartbeats due to arrhythmia, the NIBP measurement is unreliable or impossible and
measurement time increases.
3) Heart-lung Machine
Do not perform the NIBP measurement if the patient is connected to a heart-lung machine.
4) Pressure Changes
If the patient’s blood pressure changes rapidly within a certain time when the monitor analyzes the arterial pressure
pulse for measurement purpose, the NIBP measurement is unreliable or impossible.
5) Severe Shock
If the patient is under severe shock or hypothermia, the NIBP measurement is unreliable as the reduced blood flow
to the periphery will cause lower arterial pulse.
6) Extreme HR
Do not perform the NIBP measurement if the HR is lower than 40bpm (beats per minute) or higher than 240bpm.
7) Obese Patient
Due to the thick fat layer of the limb, the vibration from the artery fails to reach the cuff, which causes lower
measurement accuracy than in normal weight cases.
8) Patient with Hypertension
To measure the NIBP of a patient with hypertension accurately, follow the steps below:
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