PAC Flashcards
2 indications for PAC monitoring in ICU?
diagnosis of respiratory failure or shock
indications for PAC monitoring in OR?
poor EF, valve disorders, separation from CPB
How do you calculate O2 delivery?
CaO2 x CO
End diastolic volume is?
preload
Calculated measurements from PAC?
PVR, SVR, SV, O2 delivery
Normal value PAP?
25/10
Normal value PAOP?
8-12
Normal value SvO2?
60-75%
Normal CI?
2.5-4 L/min
Normal SVR?
900-1200 dynes/sec/cm5
Normal PVR?
50-140
Normal SV?
50-100 mL
Normal SV index?
25-45
How do you calculate SVR?
[80x (MAP-RAP)/CO]
How do you calculate PVR?
[80 x (meanPAP-LAP)/pulmonary blood flow}
Some relative contraindications to inserting PAC?
large PE, coagulopathy, ventricular ectopy, LBBB, PM, ICD, severe pulmonary artery HTN
BBB complication of PAC?
RBBB
Easier side to float from for an IJ, for a SC?
RIJ; LSC
W femoral PAC placement, you risk what 2 things mainly?
infection and DVT
What is the length to RA, RV, PA, and PAOP if inserting a RIJ?
RA- 15-20; RV-30; PA- 40; PAOP-45-50
When inserting a PAC from the femoral vein, how far is the RA?
40-45
Do you flush and 0 the PAC prior to insertion?
yes
When should you have the catheter sheath in your hand?
before you give up the cordis tray
Once the catheter tip is in the RA, you should do what?
advance the tip w the balloon inflated
How do you withdraw the PAC?
with balloon deflated
With what speed do you advance the PAC in the RV?
quickly
When do you start advancing the catheter tip slowly?
once distal tip is in the PA
Do you want the PAC tip to be in the distal or middle PA?
middle
How is LA pressure measured w a PAC?
When wedging the PAC, blood flow is stopped at that site in the PA and therefore pressure from the LA is transmitted back up to that catheter tip
The tip of the PA catheter should be seen where on a chest xray?
no more than 3-5 cm from midline
Pressures in West Zone I, II, and III look like?
I: A>a>v; II: a>A>v; III: a>v>A
PAC should be in which zone?
III
RA waveform looks like?
CVP w c, a, v upstrokes
RV waveform looks like?
brisk upstroke and downstroke
PA waveform?
brisk upstroke and downstroke flatten out and see notching
PAOP waveform?
flattened waveform
During PAC insertion, CVP pressure is measured with which part of the catheter?
when tip floats in to RA
After PAC placement, CVP is measured with what?
proximal lumen of catheter
When do a, c, and v waves occur?
a: atrial contraction; c: closure of tricuspid valve; v: blood filling atrium when tricuspid valve is closed
When does x descent occur during a CVP waveform?
fall in right atrial pressure following atrial contraction
When does y descent occur during CVP waveform?
fall in right atrial pressure following opening of tricuspid valve and passive ventricular filling
When do the EKG waveforms occur in relation to the a, c, and v waves of CVP?
a right after p wave, c right after QRS, v right at ST segment
mean RA pressure is roughly equivalent to what other pressure?
RVEDP
Some causes of elevation of RAP?
hypervolemia, PE, RV infarction, impaired RV contraction, pul HTN, pulmonic stenosis, tricuspid valve disease, left to right shunts, cardiac tamponade
Most stunning change in waveform as you go from the RV to the PA?
diastole increases
PA systolic pressure is roughly equivalent to?
RV systolic
PAOP waveform has which 2 waves?
a and v
The mean PAOP is close to which value?
PAD
If you think you are overwedging what action should you take?
put balloon down and withdraw catheter 1-2 cm
Why does overwedging occur?
the PA is completely occluded so there is no sense of LA pressure
PAEDP is equivalent to what 2 values?
PAOP and LVEDP
The PAOP a wave is always where in relation to the EKG? And what does the a wave reflect?
at the end of the QRS; reflects LA contracting, LV filling, and MV open
The PAOP v wave occurs where in relation to the EKG? And reflects what?
after T; reflects LA filling, MV closure, and LV contraction
Using the PAOP waveform, how could you estimate PAOP?
locate the a wave just prior to the pressure decline and take the average a wave value
What do inspiration and expiration do to the PAP during spontaneous ventilation and mechanical vent?
- pressure during inspiration during spontaneous breathing causes decrease in PAP, exhalation during spontaneous breathing is typically active and causes increase in PAP; on a ventilator O2 is delivered under + pressure so during inspiration the PAP increases, whereas the PAP decreases on expiration bc it is typically passive
PAP values are approximately the same at which point in the respiratory cycle and for that reason, that is when you should measure PAP?
end expiration
How should you measure a CVP reading for a spontaneously breathing pt?
find the a wave just prior to the decline and average the a wave as the mean CVP value
How do you measure a PAOP waveform in spontaneously breathing pt?
find beginning of pressure decline and locate a wave and take the mean value
How do you measure a CVP or PAOP waveform w large a waves?
locate the a wave and average it
When would you see large a waves/w what conditions?
noncompliant ventricle, mitral or tricuspid stenosis
How do you measure the CVP/PAOP when there are large a waves and a dysrhythmia?
find a normal a wave and measure the value after the QRS or if there are no normal a waves, measure the pressure value at the end of the QRS complex
Under what conditions would you not see a waves? And how would you measure the CVP/PAOP?
if the pt has a PM; measure the pressure value at the end of the QRS complex
What are some cases that would cause large V waves?
tricuspid regurg, ventricular ischemia, ventricular failure, hypervolemia
Early rapid filling comprises what % of RV filling?
60%
Slow phase filing comprises what % of RV filling?
25%
How would you detect a left to right shunt?
detection of an O2 saturation step up (>10% rise in O2 sat)
When your RAP = RVED= PCWP, that is an ominous sign and what are the 3 possibilities of what is happening?
tamponade, constrictive pericardial disease, and restrictive cardiomyopathy
To measure CO, saline is injected through which port on a PAC?
proximal
What characteristics do you want to see on a CO curve?
smooth even upstroke and downstroke
The area under a CO curve is inversely proportional to what?
rate of blood flow past the PA
CO curves should not differ by more than what % to obtain a mean CO?
10
Some physical problems that decrease the accuracy of thermodilution CO?
tricuspid regurg, septal defects
How does continuous thermodilution CO work?
theres a thermal filament located 15-25 cm from the catheter tip and it generates low energy head pulses transmitted to surrounding blood
