Passport® - Mindray

NIBP Monitoring NIBP Measurements
7.4.11 Recommendations for Automatic Blood Pressure Measurements
7.4.12 Cuff Size
The following practices are recommended when making automatically cycled blood pressure
measurements:
Position and support the limb in such a way as to minimize stretching of and weight
exertion on affected nerves
Avoid cuff placement that applies pressure on the ulnar nerve. Cuff tubing should not
exit the cuff over the course of the ulnar nerve at the elbow
Select a measurement interval that provides adequate venous drainage during cuff
deflation
Periodically inspect the limb bearing the cuff in order to detect venostasis
If necessary move cuff to another limb to relieve single-limb stress
Using a narrow cuff gives erroneously high pressure readings. If a standard cuff is applied to
an obese patient or a patient with large biceps, the extra tissue and fat will dissipate the
applied pressure requiring an additional pressure increase to collapse the artery. On the
other hand, over-wrapping a slender arm gives erroneously low pressure readings because
too much force per unit area is exerted. This requires less pressure to collapse the artery.
7.4.13 Other Factors
An accurate determination of blood pressure by the Passport V can be difficult if cardiac
rhythm is irregular. Irregular cardiac rhythm changes the stroke volume from beat to beat.
This changing stroke volume may increase the time it takes the Passport V to take a
measurement. The Passport V makes up to four successive attempts to obtain a
measurement. If a measurement cannot be taken after four tries, the numeric displays are
zeroed.
7.4.14 User Verification of Passport V Blood Pressure Measurements
Regular service to blood pressure equipment will help ensure accurate measurements.
Consult your Service Manual for appropriate information. If you question the accuracy of the
Passport V, verify the blood pressure with a manometer.
Auscultatory verification can be made at the same time the Passport V is taking a
measurement. Apply a bell stethoscope over the brachial artery. Do not allow the
stethoscope to touch either the patient’s clothing or the pressure cuff.
7.4.15 Newborn NIBP Technique
Newborn patients present unique obstacles to NIBP measurement. Their vital signs can
change from moment to moment, and their tiny physiological signals are very prone to noise
interference. The following suggestions will help you to obtain the best possible NIBP
measurement:
1. Try to measure infants when they are calm. A kicking/crying baby may disturb or jiggle
the cuff, causing noise within the system and resulting in unstable blood pressure
readings. If necessary, hold the cuffed limb steady, without impeding circulation. Do not
hold onto the cuff and do not pat the cuffed limb to comfort the child.
Passport V Operating Instructions 0070-10-0704-02 7 - 11