Philips IntelliVue MX800 - Calculating Pulse Pressure Variation

11 Monitoring Invasive Pressure
189
9
Reconnect the patient and start measuring again.
Troubleshooting the Pressure Calibration
The status line lists the probable cause of an unsuccessful calibration.
Calculating Cerebral Perfusion
The monitor can calculate the difference between mean arterial pressure and the intracranial pressure.
The difference is labeled CPP.
1 In the Main Setup menu, select Measurements.
2 In the Setup CPP menu, select one of the listed pressures as the arterial pressure source.
Calculating Pulse Pressure Variation
Note: Pulse Pressure Variation can be calculated in two different ways on this monitor - directly from
the pressure measurement or in conjunction with the CCO measurement. Refer to the Cardiac Output
chapter for information on PPV from CCO. Only one PPV can be active at a time.
Pulse Pressure Variation (PPV) is calculated from beat-to-beat arterial pressure values. Pulse pressure
is the difference between the systolic and the diastolic pressure values for a single beat. Pulse pressure
variation is defined as the maximal pressure less the minimum pressure divided by the average of these
two pressures. The average variation in pulse pressure is calculated over periods of 32 seconds.
WARNING
• This monitor can calculate PPV from beat-to-beat values of any arterial pulsatile pressure. The
circumstances under which the calculation of a PPV value is clinically meaningful, appropriate and
reliable must be determined by a physician.
• The clinical value of the derived PPV information must be determined by a physician. According
to recent scientific literature, the clinical relevance of PPV information is restricted to sedated
patients receiving controlled mechanical ventilation and mainly free from cardiac arrhythmia.
• PPV calculation may lead to inaccurate values in the following situations:
– at respiration rates below 8 rpm
Message Corrective Action
unable to calibrate - equipment
malfunction
Contact your service department. The pressure hardware is
faulty.
unable to calibrate - out of range Make sure that you have selected the value for Cal. Press that
you are applying to the transducer, and repeat the calibration.
unable to calibrate - no
transducer
Make sure that the transducer is connected and try again.
unable to calibrate - unstable
signal
Make sure there are no disturbances to the transducer, and
repeat the calibration.
unable to calibrate - perform
zero first
No valid zero. Zero the transducer.