Arterial pressure monitoring

Question 1

What are the sites for art line placement?

Answer 1

Radial, dorsalis, femoral, brachial

Question 2

What are the pros / cons of radial art line?

Answer 2

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

Question 3

What are the pros / cons of dorsalis art line?

Answer 3

Used when radial not accessible, easy

Cons: Usually inaccurate d/t small artery, risk of occlusion, pt unable to ambulate

Question 4

What are the pros / cons of femoral art line?

Answer 4

Used in cardiac arrest, shock states when peripheral pulses not palpable

Cons: Prone to kinks, risk of infection, hemorrhage, needs to be sutred in

Question 5

What are pros / cons of brachial art line?

Answer 5

Easy to access in OR, good collateral vessels

Cons: Rarely used, hard to stabilize, risk of brachial nerve damage

Question 6

How much pressure should the pressure device be inflated to?

Answer 6

250-300mm Hg

Question 7

Where is the art line transducer leveled at?

Answer 7

With the right atrium, at the phlebostatic axis (4th ICS, midaxillary line)

Question 8

What happens if the transducer is above the phlebostatic axis?

Answer 8

False decreased BP

Question 9

What happens if the transducer is below the phlebostatic axis?

Answer 9

False elevated BP

Question 10

What are the 3 pressures the art line is exposed to?

Answer 10

1) Blood pressure
2) Atmospheric pressure
3) Hydrostatic pressure

Question 11

What are the characteristics of a normal art line waveform?

Answer 11

Smooth upscale (systole) and diacrotic notch (beginning of diastole) quick downwards slope

Question 12

What does a dampened waveform look like, and what causes it?

Answer 12

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

Question 13

What is pulsus parodoxus?

Answer 13

Decrease of > 10mmhg SBP between inspiratory and expiration

Decrease on inspiration, increase on expiration

Question 14

What causes pulsus parodoxus?

Answer 14

Hypovolemia, pericardial tamponade

Question 15

What is the square wave test?

Answer 15

Pulling the flush cable should cause quick rise up, square shape, sharp fall down and 1 oscillation.

Checks integrity of transducer accuracy.

Question 16

What does an over-dampened square wave test look like and what does it represent?

Answer 16

No oscillations, square has slope downwards (not sharp), doesn’t go below baseline.

Results in false low BP

Question 17

What does an over-sensitive / under-dampened square wave test look like and what does it represent?

Answer 17

Many oscillations, pressure very peaked

Results in false high BP

Question 18

What are complications of art line?

Answer 18

Hemorrhage, hematoma (can occlude blood flow, causing ischemia), infection, air emboli, ischemic limb

Question 19

What are some ways to prevent air emboli in art line?

Answer 19

Check integrity of all ports, stopcocks, tubing, connection sites. Air should be aspirated out of NS bag prior to pressurizing

Question 20

What should be checked prior to art line removal?

Answer 20

Coag studies, platelet count

Question 21

How long should pressure be maintained on the site after art line removal?

Answer 21

5-20 mins

Question 22

Troubleshooting: Dampened arterial waveform

Answer 22

Check manual BP
Possible air in line or transducer
Kink in catheter 
Decreased pressure in flush bag?
BRoken transducer?
Potential clot

Question 23

Troubleshooting: Art line has a clot

Answer 23

Aspirate clot, do not fast flush

Question 24

Troubleshooting: Flat line

Answer 24

Stopcock turned incorrectly?
Catheter out of artery?
Complete occlusion / clot?

Question 25

Troubleshooting: No waveform

Answer 25

Check connection to monitor

Question 26

Troubleshooting: Unable to aspirate blood

Answer 26

Possible arterial spasm –> aspirate slowly and gently

Catheter against vessel wall –> Reposition limb

Kinked at site –> Redress, inspect catheter