PA Lines Flashcards
What are indications for the placement of PA line?
cardiogenic shock, pulmonary HTN, pre/post cardiac surgery management
What are normal values for CVP/RA pressures? What does this information tell us?
2-6/0-8 mmHg. Tell us about R heart preload.
When would we see RV pressures? What are normal ranges?
Seen during insertion only. RV systolic 20-30, RV diastolic 0-6.
What are normal PAS pressures? What does this number tell us?
20-30 mmHg. Tell us about pulmonary systolic pressures.
What are normal PAD pressures? What does this number tell us?
8-15 mmHg. Preload of L heart.
What are normal PA mean pressures?
10-20 mmHg
What are normal PCWP? What does this number tell us?
8-12 mmHg. Preload L heart.
What are normal SVR numbers? What does this tell us?
900-1400 dynes. Afterload of L heart. SYSTEMIC vascular resistance.
What are normal PVR numbers? What does this tell us?
50-150 dynes. Afterload of R heart. PULMONARY vascular resistance.
What are normal CO ranges?
4-8 lpm
What are normal CI ranges?
2.5 - 4 lpm
PCWP should always be below PADP by how much?
1-4 mmHg
Why is PADP used to estimate LV preload instead of PCWP routinely?
PCWP measurements increase risk of trauma and rupture to pulmonary artery. As long as PADP and PCWP correlate well (within 1-4 mmHg of eachother) then PADP can be used to determine LV preload
If the PADP is >4 mmHg than PCWP, what does this signify?
Patient is expereincing significant lung pathology
Can PCWP be higher than PADP?
no it is physically impossible
When obtaining a PCWP what are some safety things to consider?
- only inject amount of air required to obtain a PCWP waveform (even if it is less than 1.5 cc)
- observe PCWP waveform for 2-3 resp cycles and at end-respiration
- disconnect syringe and allow balloon to deflate passively
How is a patient positioned when obtaining PCWP?
HOB elevated <45 degrees, supine
Why is it important to read PCWP values at end-expiration?
Minimizes influence of intrathoracic pressure fluctuations
What are important steps to remember when obtaining cardiac outputs from a PA line?
- injectate must be 10 degrees colder than blood
- inject smooth and fast (no longer than 4 seconds)
- must obtain 3 COs and discard values that are >10% different from eachother. all three values must be within 10 % of eachother
What will a high CO produce when injectate is injected?
Quick rise to peak and a quicker return to baseline (less area under curve) as fluid passes the thermistor more quickly
What will a low Co produce when injectate is injected?
Cure will have lower peak and will occur over a longer period of time as it takes more time for the cold fluid to pass the thermistor. Larger SA will be seen under curve.
What is CI?
CO calculated with BSA
When is it important to obtain a hemodynamic profile?
- baseline
- any acute changes
- to assess specific interventions (fluid, vent setting changes, med titrations)
- determine optimal PEEP
- determine optimal FB
- unit policy
What needs to happen if the PAC is spontaneously wedging?
PAC needs to be pulled back. Nursing can pull back under direction from doc, but not allowed to advance.
What are risks associated with spont wedging?
occluding BF and ischemia
What could be causes of dampened PA waveform?
- air in system, clot, catheter kinked, pressure bag <300, crack in transducer, incorrect stop-cock placement, blood in tubing
What could be causes of PCWP pressure tracing unobtainable?
balloon ruptured, cath no longer in place
what could be the cause of spont wedging in waveform? what should you do?
catheter is in too far. deep breathe/cough, position change (roll side to side), call doc as cath needs repositioning.
what could be the cause of RV waveform appearing?
cath slipped back into RV
What PAC value will tell us about CO/EOP?
Mixed venous O2 sat (SVO2)
What PAC values will tell us about preload?
RA/CVP, PCWP
What PAC values will tell us about afterload?
MAP, SVR, PVR
What PAC values will tell us about contractility?
CO, CI
