Hemodynamic monitoring Flashcards
What is the ideal length of the bladder size of a BP cuff? Width?
Length - 80%
Width - 40%
If the cuff is too small, what will the BP read?
Overestimates because it takes more pressure
If the cuff is too large, what will the BP read?
Underestimates because it takes less pressure
Where is the widest pulse pressure when measuring BP?
Foot
SBP is the highest
DBP is the lowest
Where is the narrowest pulse pressure when measuring BP?
Aortic root
If the BP cuff is above the heart, the BP reading will be;
Falsely decreased
If the BP cuff is below the heart, the BP reading will be;
Falsely increased
Over dampened or under dampened? SPB is overestimated and DPB is underestimated?
Under dampened
** many oscillations
What causes an under dampened art line?
Stiff, non compliant tubing
Catheter whip
Over dampened or under dampened? SPB is underestimated and DPB is overestimated?
Over dampened
** no oscillations
What causes an over dampened art line?
Air bubble
Clot
Low pressure bag pressure
Kinks
Loose connection
Is the MAP accurate with an over or under dampened art line?
YES
How far should a central line be advanced through the R IJ to achieve correct placement?
15 cm
What is at increased risk when placing a Left central line?
Puncturing the thoracic duct
When are dysrhythmias most common to occur? Treatment?
While obtaining access
Pull back
When does the indcidence of infection increase?
After three days
When shouldn’t you float a PAC?
A patient with a LBB because it floating the PAC may trigger a RBB which would put the patient into complete heart block
What is the classic presentation for pulmonary artery rupture?
Hemoptysis
What increases the risk of a pulmonary rupture?
Anticoagulation
Hypothermia
Advanced age
Using liquid in the balloon
Chronic inflation of balloon
Unrecognized wedging
Distances of catheter insertion ***
What is the A wave on the cvp pressure waveform?
RA contraction
First upstroke
What is the c wave on the cvp pressure waveform?
Tricuspid closure - RV contraction
Second upstroke
What is the x wave on the cvp pressure waveform?
RA relaxation
first major downslope
What is the v wave on the cvp pressure waveform?
Ra passive filling
What is the y wave on the cvp pressure waveform?
RA empties into RV through open tricuspid valve
What increases RA pressures
Low transducer
Hypervolemia
Tricuspid stenosis or regug
VSD
PEEP
Tamponade
Constrictive pericarditis
RV failure
Pulmonic stenosis
When should CVP be measured? Where?
End expiration
4th intercostal space, mid anteroposterior level
What is a normal CVP?
1-10
What is CVP measurement a function of?
Intravascular volume
Venous tone
RV compliance
Factors that decrease CVP?
High transducer
Hypovolemia
When is the a wave lost on a CVP?
Afib
V pacing if the underlying rhythm is asystole
What increases the amplitude of the a wave on the CVP?
Tricuspid stenosis
Diastolic dysfunction
myocardial ischemia
Lung disease
AV dissociation
Junctional rhythm
V pacing - asynchronous
PVCs
What causes a large V wave?
Tricuspid regurg
Acute increase in volume
RV papillary muscle ischemia
What changes do you see when the PA catheter enters the RV?
Systolic pressure increases
Diastolic is equal to CVP
What changes do you see when the PA catheter enters the Pulmonary artery?
Systolic stays the same
Diastolic pressure rises
Dicrotic notch is seen
What changes do you see when the PA is wedged?
Same waveform as the CVP but with the L side of the heart
What are the pressures in the RVP?
15-30
0-8
What are the pressures in the PAP
25/10
What are the pressures in the PAOP (wedge)
5-15
Which lung zone should the tip of the PA catheter be in?
Zone 3
What suggests the PA tip is not in zone 3?
Can’t draw blood because it is wedged
Nonphaseic PAOP tracing
PAOP > PA end diastolic
What causes PAOP to underestimate LVEDV?
aortic valve insufficiency
What causes PAOP to overestimate LVEDV?
Everything but aortic valve insufficiency and correct placement
Which situation underestimates cardiac output obtained by thermodilution ?
High injectate volume or cold
When can thermodilution not predict ?
Intracardiac shunt
Tricuspid regurgitation
Where and how should the thermodilution be administered?
5% dextrose or NS through the proximal port in under 4 seconds
When should thermodilution be used versus continuous cardiac output?
in unstable patients
Why is a PA catheter necessary to measure SvO2?
Need a collection of all venous blood
SVC
IVC
Coronary sinus
What is a normal SvO2? What is needed to measure?
65-75%
CO
VO2
Hgb
SaO2
What is pulse contour analysis? How does it work?
Indicator on how the patient will respond to a 250mL bolus of fluid
Measures the stroke volume variation during the respiratory cycle
or
the change in intrathoracic pressure
If the SVV is >13% will the patient respond to a 250mL bolus? <13%?
yes they will respond if the SVV is > than 13%
What limits the use of SVV?
Spontaneous Ventilation
PEEP
Dysrhythmias
Open chest
RV dysfunction
Small Tv
What are contraindications to using esophageal doppler?
Esophageal disease
How much will the BP change for every 10cm? every inch?
10cm - 7.5mm
Inch - 2mm
What does the upstroke on an Aline tell you?
the contractility
What does the dicrotic notch tell you on an Aline?
closure of the Aortic valve
How is the pulse pressure calculated on an Aline?
Peak - trough
How does the cvp waveform correlate to the electrical activity of the heart
