Arterial cannulation, puncture

Question 1

Indications for arterial cannulation

Answer 1

Beat-to-Beat BP monitoring
- shock syndrome, cardiac arrest, HTN crisis
Multiple ABG analysis
- resp failure, sepsis

Question 2

Complications from arterial cannulation

Answer 2

Infection
Hemorrhage -> hematoma
Ischemia -> gangrene & necrosis (perform Allen's test)
Thromboembolization
Air emboli
A-V fistula
Vasovagal response
Vasospam
intra-arterial drug administeration
nerve injury

Question 3

Possible sites for arterial cannulation

Answer 3

Radial
Brachial
Femoral
Ulnar
Dorsalis pedis
Axillary

Question 4

What is direct/invasive BP monitoring based on?

Answer 4

Pressure

Question 5

What is indirect/non-invasive BP monitoring based on?

Answer 5

Flow

Question 6

Is there a difference in measurements between Direct and Indirect measurements? If so, by how much?

Answer 6

Yes, direct will be 5-20mmHg greater than the cuff

if direct is 20-30 mmHg greater than cuff then there is an issue with the equipment or the pt is very vasocontricted

Question 7

What width and height does the cuff/bladder need to be?

What will happen to the BP reading if the cuff is too small?

Answer 7

20-50% of the circumference
60% coverage in length of arm

If too small, the reading will be falsely high

Question 8

Regarding the fluid filled in the tubing, what variables can affect the accuracy of the waveform readings?

Answer 8

If tubing too long, can cause lag time

If HR is rapidly increasing or decreasing, the system will have a hard time keeping up with the changes

Question 9

Describe overdamping (blunted - undershoot)

Answer 9

machine NF < pulse NF
low systolic
high diastolic
not exceeding below baseline
no ringing

Question 10

Describe underdamping (exaggerated - overshoot)

Answer 10

machine NF = pulse NF
spiked systolic
low diastolic
increased ringing
difficult to read waveform

Question 11

What is a Square Wave Test?

Answer 11

To determine if system is under or overdamped

Question 12

What is a Dynamic Response Test?

Answer 12

Assessing the NF of the machine

Question 13

Name the fluid system factors that may affect the NF

Answer 13

Tubing length
Air bubbles, blood clot
Compliance of tubing
Size of catheters

Question 14

Name the pt related factors that may affect the NF

Answer 14

Hyperdynamic circulation
Hypertension
Atherosclerosis
Tachycardia

Question 15

Name the phases of an arterial pressure waveform

Answer 15

Phase I: Anacrotic Rise
Phase II: Volume displacement
- anacrotic notch
- dicrotic notch
Phase III: Late systole and diastole

Question 16

Troubleshoot: getting abnormally high or low arterial cannulation waveforms. What is the cause and treatment?

Answer 16

Transducer placement is not at reference level

Place transducer at mid-axillary line/right atrium/phlebostatic axis/4th intercostal space

Question 17

Complications from Arterial PUNCTURE

Answer 17

arteriospasm
pain
vasovagal response
hemorrhage
hematoma
infection
air emboli
thrombus/embolus
allergic response to lidocaine
trauma to the vessel
arterial occlusion

Question 18

What errors could occur when drawing an ABG?

Answer 18

Air in sample
Venous admixture
Metabolic component