Advanced Hemodynamics - Orlando Health

Advanced Hemodynamic Monitoring
for gas exchange to occur. Otherwise, if the pressure becomes too high, the intravascular fluid is
forced into the alveoli which results in impaired gas exchange and pulmonary edema.
Reading
obtained
from the
PA-
Catheter
Once the PAC is inserted, the pulmonary artery pressures can be continuously measured. More
specifically, the pulmonary artery systolic (PAS) and the pulmonary artery diastolic (PAD) will be
displayed. The PAS pressure reflects the amount of pressure necessary to open the pulmonic valve
and eject the blood into the pulmonary circulation. The PAD pressure reflects the amount of
resistance in the lungs between heart beats.
As previously mentioned, the PAS and PAD both reflect right-sided pressures. When elevated, this
indicates a problem with the lungs. In addition, assessment of the PA pressures can also help in
distinguishing between a primary lung problem and a lung problem caused by the heart. The
pulmonary artery pressures will increase whenever the blood vessels in the lungs are constricted.
This is also known as increased pulmonary vascular resistance (PVR). PVR is considered the
afterload of the right ventricle. Conditions such as pulmonary hypertension, chronic hypoxemia, or
pulmonary embolus can result in an increased PVR leading to elevated pulmonary artery pressures.
As previously mentioned, once the PAC is inserted the tip rests in the pulmonary artery. An
electronic signal is sent to the monitor which will display a waveform. This waveform may vary
with respirations and the monitor will average this variation in its readings. This is why it is
imperative that the clinician print out a copy of the wave form display to properly assess the value.
The measurement should always be assessed at end expiration. In a spontaneously breathing patient
the intrapulmonary pressures decrease slightly on inspiration, and increase on expiration. The
opposite is true for a mechanically ventilated patient. In a patient that is mechanically ventilated the
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