Pulmonary Capillary Wedge Pressure Flashcards
The ____ is also used to measure the pulmonary capillary wedge pressure (PCWP) (also called pulmonary artery wedge pressure).
pulmonary artery catheter
___ is measured by slowly inflating the balloon via the balloon inflation port on the pulmonary artery catheter.
PCWP
As the balloon inflates, the pulmonary arterial waveform on the monitor will change to the ____ .
wedged pressure waveform
Proper inflation of the balloon usually requires no more than ___ ( ____depending on size of balloon) of air.
1.5 mL (0.75 to 1.5 mL
The balloon is ___ as soon as the reading of PCWP is obtained.
deflated
The ____ reading is typically taken at end-expiration for both spontaneous breathing and mechanically ventilated patients
PCWP
This practice should be done consistently for consistent ____ measurements and meaningful interpretation of hemodynamic data.
PCWP
____ reflects the left ventricular preload.
PCWP
The components of the ____ waveform are similar to the CVP or right atrial wave- form.
PCWP
the ___ wave of the PCWP waveform reflects left atrial contraction
a
____ downslope represents the decrease in left atrial pressure following contraction.
x
The ____ wave, if present, is seen along the x downslope, and it occurs during closure of the mitral valve.
c
The ____ wave indicates left ventricular contraction and passive atrial filling.
v
The ___ downslope is due to the decrease in blood volume and pressure following the opening of the mitral valve
y
Increased PCWP measure- ments are often observed in conditions where ____ or ____ is present in the left heart
partial obstruction / excessive blood flow
Two common changes in the PCWP waveform are the ___ and ___ waves.
a and v waves
The __ wave of the PCWP waveform may be increased in conditions leading to higher resistance to left ventricular filling.
a
The a wave of the PCWP waveform may be increased in conditions leading to higher resistance to left ventricular filling. Some examples are _____, ______, and ______.
mitral valve stenosis,
left ventricular hypervolemia or failure,
and decreased left ventricular compliance.
The ____ wave of the PCWP waveform may be increased due to mitral valve insufficiency.
v
The v wave of the PCWP waveform may be increased due to mitral valve insufficiency. This condition leads to ____ (backward flow) of blood from the left ventricle to the left atrium through the incompetent mitral valve.
regurgitation
The normal range for PCWP is from ____.
8 to 12 mm Hg
______ can affect wedge pressure readings since over distension of the alveoli com- presses the surrounding capillaries and raises the capillary and arterial pressures.
Positive pressure ventilation or PEEP
A higher than normal wedge pressure may also be seen in ______.
left ventricular dysfunction
This is because _____ causes backup of blood flow in the left heart and pulmonary circulation.
left ventricular failure
A PCWP reading of _____along with a near- normal PAP suggests presence of left ventricular dysfunction or left heart failure.
≥18 mm Hg
The ___ measurement may be used to distinguish cardiogenic and noncardio- genic pulmonary edema.
PCWP
____ that is caused by left ventricular failure, the PCWP is usually elevated (≥18 mm Hg) along with a near-normal PAP.
pulmonary edema
In pulmonary edema where the PCWP is normal, the cause may be ______ or an increase in ____ (e.g., ARDS).
acute pulmonary hypertension / capillary permeability
~Increase in pulmonary blood flow Left heart pathology
~Mechanical factor
Give examples of
PCWP Increase /
Hypervolemia
Left ventricular failure;
Mitral valve disease Overwedging of balloon
Mechanical ventilation
Decrease in pulmonary blood flow
PCWP Decrease /
PEEP
Hypovolemia
Since ___ or ___ waveform may occur during inflation of the balloon, and it resembles that of a wedged pressure tracing, using the PCWP tracing alone on the monitor to verify the wedged position may not be always reliable.
artifact or dampened
Three methods are available to confirm a properly wedged pulmonary artery catheter:
(1) PAP diastolic-PCWP gradient;
(2) postcapillary-mixed venous PO2 gradient; and
(3) postcapillary-mixed venous O2 saturation gradient.
Under normal conditions, the PAP diastolic value is about _____ higher than the average wedge pressure of the same individual (PAP Diastolic-PCWP Gradient)
1 to 4 mm Hg
However, the PAP diastolic value may be lower than actual with _____.
forceful spontaneous inspiratory efforts
The PCWP may be higher than actual if there is significant downstream obstruction such as _____
mitral valve disease
The PO2 of a blood gas sample from the distal opening of a properly wedged catheter should be at least ____ than that from a systemic artery.
19 mm Hg higher
The PCO2 should be at least _____.
11 mm Hg lower
These differences are expected because a ___ wedged catheter does not allow mixing of shunted venous blood with the postcapillary (oxygenated) blood.
properly
This procedure may not be feasible for a hypovolemic patient because up to ___ of waste (mixed venous) blood sample may be required before reaching the postcapil- lary blood sample
40 mL
This procedure may not be feasible for a hypovolemic patient because up to 40 mL of waste (mixed venous) blood sample may be required before reaching the postcapil- lary blood sample
Postcapillary-Mixed Venous PO2 Gradient.
If the pulmonary artery catheter is capable of monitoring oxygen saturation by the oximetry method, the oxygen saturation value of a properly wedged catheter should be about ____ than the one recorded with the balloon deflated
20% higher
If the pulmonary artery catheter is capable of monitoring oxygen saturation by the oximetry method, the oxygen saturation value of a properly wedged catheter should be about 20% higher than the one recorded with the balloon deflated
Postcapillary-Mixed Venous O2 Saturation Gradient.
