VI. Checking for Leaks
After approximately 1 minute has elapsed, the flow rate should be observed at the drip chamber
to ensure that the continuous flush device is operating properly. A visual inspection for leaks
should also be made since a small leak can misrepresent the actual continuous flow through the
catheter. A protocol should be established according to the hospital standard of care for routinely
checking the system for proper fluid source pressure, flow rate and leaks.
VII. In the MR Room
In the MR room, ensure that the transducer is level with the heart that the transducer interface
cabling is not looped or touching the patient (refer to the Warnings on pages 8‐3 and 8‐4), and
then re‐zero the transducer; see page 8‐16.
Non-physiological pulsatile P1 (or P2) waveform (for example, those found during intra-
aortic balloon pump use) can lead to inaccurate blood pressure readings. If questionable
values are observed, recheck the patient's pressures by alternate means before administering
medication or therapy.
Expression MR400 Instructions for Use
Be certain not to introduce air into the system during connection procedure.
If this product is used with fat emulsions, they must be introduced through the lipid
compatible stopcock that is distal to the flush transducer assembly to avoid cracking of the
The IBP transducer must not be allowed past the 5,000 gauss line, or transducer
failure, inaccurate readings, noisy MRI images or patient burn may result.
Never place the pressure transducer's stopcocks or port covers within 8 cm (3.2
inches) of the field of view of the MR bore as inaccurate readings or noisy MRI images
An offset occurs when the pressure transducer is repositioned in the magnetic field.
The transducer must be zeroed prior to the MRI examination after the transducer is in
its final setup position. Moving the transducer after zeroing may cause a measurement
offset to occur.
Monitoring Invasive Blood Pressure 8‐15