13 Monitoring Invasive Pressure
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Determining a Pressure's Most Recent Zero
The monitor displays the most recent zero on the status line. If this has "timed-out" after you have
performed a zero, redisplay the information in the status line by entering the pressure's setup menu.
Zeroing a Pressure Measurement
WARNING
Invasive pressure alarms (and pulse alarms, if derived from invasive pressure) are temporarily
suppressed until 30 seconds after the transducer finishes zeroing.
1 Turn off the stopcock to the patient.
2 Vent the transducer to atmospheric pressure, to compensate for the static and atmospheric
pressure exerted on the transducer.
3 In the setup menu for the pressure, select Zero <Press Label>.
4 When you see the message <Press Label> zero done at <Date and Time> on the status line, close
the stopcock to atmospheric pressure, and open the stopcock to the patient.
CAUTION
When using high frequency ventilation, ensure that the tubing from the ventilator does not touch the
arterial line, or connect with it indirectly, while zeroing the pressure. This could cause small pressure
variations which can interfere with the zero procedure.
Zeroing All Pressures Simultaneously
WARNING
Before zeroing all pressures, make sure that all pressure transducers are vented to atmospheric
pressure.
If you are measuring pressures with more than one measuring device, using the Zero Press SmartKey to
initiate the zeroing calls up a list of all active pressures. Select the pressure you want to zero or select
All
Press
to zero all pressures simultaneously.
Troubleshooting the Zero
The status line lists the probable cause of an unsuccessful zero:
Message Corrective Action
<Press Label> can't zero;
equipment malf.
The hardware is faulty. Contact your service personnel.
<Press Label> can't zero;
excessive offset
Make sure the transducer is vented to air and try again. If this fails, the
hardware may be faulty. Replace the adapter cable and try again. If it fails,
replace the transducer and try again. If it still fails, contact your service
personnel.
<Press Label> can't zero
- unstable signal