User manual

User Manual for Multi-parameter Patient Monitor
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4. The studies have shown that the Korotkoff Sound Method has the worst accuracy when it comes to
measurement of hypotension, while the oscillating method has worse accuracy when it comes to
measurement of controlled hypertension relief.
7.3.2 Points to be Noted in Measurement of Blood Pressure
Like common non-invasive blood pressure measurement, improper operation may cause inaccurate or blank result
or misunderstanding of the measuring information when the oscillating method is used to take the measure of
blood pressure. This point needs particular attention of the operators.
1. Requirements of the cuff:
1) Appropriate cuff should be selected according to the age of the subject. For more information, see
Chapter 3.
2) Remember to empty the residual air in the cuff before the measurement is commenced.
3) Locate the cuff in such a way that the “φ” mark is at a location where the clearest pulsation of brachial
artery is observed.
4) The cuff should be tightened to a degree where insertion of one finger is allowed.
5) The lower end of the cuff should be 2cm above the elbow joint.
2. The subject should lie on the back so that the cuff and the heart are in a horizontal position and the most
accurate measure is taken. Other postures may lead to inaccurate measurement.
3. Do not speak or move before or during the measurement. Care should be taken so that the cuff will not be
hit or touched by other objects.
4. The measures should be taken at appropriate intervals. Continuous measurement at too short intervals may
lead to pressed arm, reduced blood flow and lower blood pressure, and resulting inaccurate measure of
blood pressure. It is recommended the measure be taken at intervals of more than two minutes.
5. With the oscillating method, when blood pressure is measured, the inflation pressure of the cuff will be
automatically adjusted according to the previous measure. Generally, the initial inflation pressure is
180mmHg (for the adult mode) or 100mmHg (for the infant mode) or 80 mmHg (for the neonate mode)
when it is powered on. Following that, 50mmHg (for the adult mode) or 30mmHg (for infant mode) or
10mmHg (for the neonate mode) will be added on the basis of the last measurement of systolic pressure.
In this way, when the blood pressure rises or the subject is changed, the blood pressure meter may fail in
giving the result after the first-time inflation. This monitor will automatically adjust the inflation pressure
until the measure is taken, after that, up to four measures will be allowed.
6. When an adult subject is monitored, the machine may fail in giving the blood pressure measure if the
infant or neonate mode is selected.
7.3.3 Clinical Limitations
1. Serious angiospasm, vasoconstriction, or too weak pulse.
2. When extremely low or high heart rate or serious arrhythmia of the subject occurs. Especially auricular
fibrillation will lead to unreliable or impossible measurement.
3. Do not take the measurement when the subject is connected with an artificial heart-lung machine.
4. Do not take the measurement when the subject uses diuresis or vasodilator.
5. When the subject is suffering from major hemorrhage, hypovolemic shock and other conditions with
rapid blood pressure change or when the subject has too low body temperature, the reading will not be
reliable, for reduced peripheral blood flow will lead to reduced arterial pulsation.