Hemodynamic monitors and equipment 2 Flashcards
What is the approximate distance from the vena cava/right atrial junction to the right atrium?
0-10 cm
What is the approximate distance from the vena cava/right atrial junction to the right venticle?
10-15 cm
What is the approximate distance from the vena cava/right atrial junction to the pulmonary artery?
15-30 cm
What is the approximate distance from the vena cava/right atrial junction to the PAOP position?
25-35 cm
The CVP waveform reflects
the pressure inside the right atrium
The CVP waveform has ____________ peaks and ______ troughs
three peaks (A, c, v) and two troughs (x, y)
The A wave is equivalent to the
RA contraction
The C wave is equivalent to the
tricuspid valve elevation into the RA
The X decent is equivalent to the
downward movement of the contracting RV
The V wave is equivalent to the
passive filling of the RA
The CVP waveform is a reflection of the
pressure inside the right atrium
What is the electrical event associated with the A wave of the CVP waveform?
just after P wave (atrial depolarization)
What is the electrical event associated with the C wave of the CVP waveform?
Just after QRS complex (ventricular depolarization)
What is the electrical event associated with the X descent of the CVP waveform?
ST segment
What is the electrical event associated with the V wave of the CVP waveform?
Just after T wave begins (ventricular depolarization)
What is the electrical event associated with the Y descent of the CVP waveform?
after T wave ends
Central venous pressure is:
a. falsely increased by placing the transducer above the zero point
b. increased by PEEP
c. decreased by pericardial tamponade
d. unchanged by a ventricular septal defect
b. increased by PEEP
The CVP should be zeroed at the
fourth ICS at the mid anteroposterior level (phlebostatic axis)
The CVP measurement is best taken at
the end-expiration
The normal CVP in the adult is
1-10 mmHg
The CVP is not a great monitor of
real-time intravascular volume assessment
Factors that increase CVP include
hypervolemia
tricuspid stenosis or regurgitation
pulmonary hypertension
cardiac tamponade
PEEP
VSD
constrictive pericarditis
pulmonic stenosis
RV failure
A low CVP is almost always caused by
hypovolemia or if the transducer is moved above the zero point
A CVP transducer placed above the zero point will
underestimate CVP
Central venous pressure is a function of
intravascular volume
venous tone
right ventricular compliance
Which conditions increase the amplitude of the a wave on the CVP waveform? (select 2)
a. tricuspid stenosis
b. atrial fibrillation
c. diastolic dysfunction
d. tricuspid regurgitation
a. tricuspid stenosis
c. diastolic dysfunction
Select causes of a missing a wave include
atrial fibrillation & V-pacing if the underlying rhythm is asystole
Select causes of a large a wave include
tricuspid stenosis, diastolic dysfunction, myocardial ischemia, chronic lung disease leading to RV hypertrophy, junctional rhythm, PVCs, & AV dissociation
Select causes of a large v wave include
tricuspid regurgitation, acute increase in intravascular volume, & RV papillary muscle ischemia
The diastolic pressure __________ as the tip of the PAC catheter moves beyond the pulmonic valve
rises
______________- is formed during pulmonic valve closure during diastole with a PAC.
The dicrotic notch
The pulmonary artery occlusion pressure is an estimate of
left ventricular end diastolic pressure
When the PAC is in the right ventricle, the waveform changes in the following ways:
the systolic pressure increases
the diastolic pressure is equal to CVP
The waveform of the pulmonary artery occlusion pressure (wedge pressure) is akin to the
CVP of the left heart
The a wave of the pulmonary artery occlusion pressure is caused by
left atrial systole
The c wave of the pulmonary artery occlusion pressure is caused by
mitral valve elevation into the LA during LV systole
The v wave of the pulmonary artery occlusion pressure is caused by
passive left atrial filling
Normal systolic right ventricular pressure is
15-30 mmHg
Normal diastolic right ventricular pressure is
0-8 mmHg
Normal systolic pulmonary artery pressure is
15-30 mmHg
Normal diastolic pulmonary artery pressure is
5-15 mmHg
Normal pulmonary artery occlusion pressure is
5-15 mmHg
In which lung zone should the tip of the pulmonary artery catheter be placed?
zone 3
Zone 3 is the _______ region of the lung
dependent
Things that suggest that the tip of the PA catheter is NOT in zone 3 include:
PAOP>pulmonary artery end-diastolic pressure
non-phasic PAOP tracing
inability to aspirate blood from the distal port when the balloon is in the wedged position
Why should the tip of the PA catheter be positioned in zone 3?
continuous column of blood between the tip of the PAC and the left ventricle (LVEDP reflects back through the pulmonary circulation)
