Arterial pressure monitoring Flashcards
What are the sites for art line placement?
Radial, dorsalis, femoral, brachial
What are the pros / cons of radial art line?
Pros: Superficial, easy to locate and cannulate, can perform allens test for collateral circulation
Cons: Thrombus with long term use, sometimes difficult to palpate, contraindicated in arm with AV fistula, decrease accuracy with peripheral constriction
What are the pros / cons of dorsalis art line?
Used when radial not accessible, easy
Cons: Usually inaccurate d/t small artery, risk of occlusion, pt unable to ambulate
What are the pros / cons of femoral art line?
Used in cardiac arrest, shock states when peripheral pulses not palpable
Cons: Prone to kinks, risk of infection, hemorrhage, needs to be sutred in
What are pros / cons of brachial art line?
Easy to access in OR, good collateral vessels
Cons: Rarely used, hard to stabilize, risk of brachial nerve damage
How much pressure should the pressure device be inflated to?
250-300mm Hg
Where is the art line transducer leveled at?
With the right atrium, at the phlebostatic axis (4th ICS, midaxillary line)
What happens if the transducer is above the phlebostatic axis?
False decreased BP
What happens if the transducer is below the phlebostatic axis?
False elevated BP
What are the 3 pressures the art line is exposed to?
1) Blood pressure
2) Atmospheric pressure
3) Hydrostatic pressure
What are the characteristics of a normal art line waveform?
Smooth upscale (systole) and diacrotic notch (beginning of diastole) quick downwards slope
What does a dampened waveform look like, and what causes it?
Waveform appears smaller in amplitude, loss of diacrotic notch.
Can be caused by kink in the catheter, air in transducer, inaccurate leveling, pressure in pressure bag, clots. CHECK MANUAL CUFF to confirm pressure.
Arrythmias can cause irregular, dampened waveforms
What is pulsus parodoxus?
Decrease of > 10mmhg SBP between inspiratory and expiration
Decrease on inspiration, increase on expiration
What causes pulsus parodoxus?
Hypovolemia, pericardial tamponade
What is the square wave test?
Pulling the flush cable should cause quick rise up, square shape, sharp fall down and 1 oscillation.
Checks integrity of transducer accuracy.
What does an over-dampened square wave test look like and what does it represent?
No oscillations, square has slope downwards (not sharp), doesn’t go below baseline.
Results in false low BP
What does an over-sensitive / under-dampened square wave test look like and what does it represent?
Many oscillations, pressure very peaked
Results in false high BP
What are complications of art line?
Hemorrhage, hematoma (can occlude blood flow, causing ischemia), infection, air emboli, ischemic limb
What are some ways to prevent air emboli in art line?
Check integrity of all ports, stopcocks, tubing, connection sites. Air should be aspirated out of NS bag prior to pressurizing
What should be checked prior to art line removal?
Coag studies, platelet count
How long should pressure be maintained on the site after art line removal?
5-20 mins
Troubleshooting: Dampened arterial waveform
Check manual BP Possible air in line or transducer Kink in catheter Decreased pressure in flush bag? BRoken transducer? Potential clot
Troubleshooting: Art line has a clot
Aspirate clot, do not fast flush
Troubleshooting: Flat line
Stopcock turned incorrectly?
Catheter out of artery?
Complete occlusion / clot?
Troubleshooting: No waveform
Check connection to monitor
Troubleshooting: Unable to aspirate blood
Possible arterial spasm –> aspirate slowly and gently
Catheter against vessel wall –> Reposition limb
Kinked at site –> Redress, inspect catheter
