Filter
Top Products
12 Monitoring Invasive Pressure Measuring Pulmonary Artery Wedge Pressure
158
• 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.
To select an arterial pressure as PPV source:
1 In the Main Setup menu, select Measurements.
2 In the Setup PPV menu, select ABP, ART, Ao, BAP, P or FAP as the arterial pressure source.
CAUTION Older measurement servers cannot supply a beat-to-beat arterial pressure value. In this case the
monitor shows a NO PPV FROM <Server> INOP.
At respiration rates below 8 rpm, PPV calculation may lead to inaccurate values.
Measuring Pulmonary Artery Wedge Pressure
Pulmonary Artery Wedge Pressure (PAWP) values, used to assess cardiac function, are affected by:
•Fluid status
• Myocardial contractility
• Valve and pulmonary circulation integrity
Obtain the measurement by introducing a balloon-tipped pulmonary artery flotation catheter into the
pulmonary artery. When the catheter is in one of the smaller pulmonary arteries, the inflated balloon
occludes the artery allowing the monitor to record changes in the intrathoraic pressures that occur
throughout the respiration cycle. The pulmonary wedge pressure is the left ventricular end diastolic
pressure (preload).
The most accurate PAWP values are obtained at the end of the respiration cycle when the intrathoraic
pressure is fairly constant. Use the ECG waveform to determine the waveform of the wedge pressure.
You can use the respiration waveform as a reference when assessing the PAWP waveform, to ensure
constant measurement timing relative to the respiratory cycle. The monitor displays the PAWP value
for up to 48 hours or until you admit a new patient.
WARNING The pressure receptor in the catheter records pressure changes that occur only in front of the
occlusion. Even though the catheter tip is in the pulmonary artery, the receptor records pressure
changes transmitted back through the pulmonary circulation from the left side of the heart.
While performing the wedge procedure, the monitor switches off the pressure alarms for pulmonary
artery pressure (PAP).
Due to a slight measurement delay, you should not use Microstream (sidestream) CO
2
as a direct
reference for determining the end expiratory point in the pressure curve.
To start the Wedge procedure,
1 In the Main Setup menu, select Wedge to display the wedge procedures window.
2 Prepare and check the pressure line according to your hospital policy. If the PAP waveform scale is
set to
Optimum prior to the wedge procedure, it is possible that after wedging the catheter, the
resulting pressure waveform will fall below the lower scale. In this case, the wedge waveform will