Ch 14 IABP

Question 1

What are the 8 indications for IABP?

Answer 1

• Unstable angina
• Acute MI
• Cardiogenic Shock
• Mechanical Complications following MI
• Adjunct to Percutaneous Transluminal Coronary Angioplasty (PTCA)
• Adjunct to cardiac cath
• BTT
• Operative (pre, intra, and post) support

Question 2

What are 5 contraindications to IABP?

Answer 2

ABSOLUTE:

• Thoracic / Abdominal Ao Aneurysm
• Occluded Aorta

RELATIVE:

• AI
• Severe PVD
• Disease not amenable to definitive therapy

Question 3

What are 7 complications to IABP ?

Answer 3

• Limb Ischemia
• Thromboembolism
• Aortic Dissection
• Vascular Injury (laceration, false aneurysm, hematoma)
• Infection
• Balloon Rupture
• Thrombocytopenia

Question 4

What medication must be given when initiating IABP therapy?

Answer 4

Heparin 5,000 units IV

Question 5

Before you remove the IAB from the holder, what kind of preparation must be done to the IAB?

Answer 5

Negative pressure applied to the IAB with the one-way valve in place.

Question 6

Inflation of the IAB causes what?

Answer 6

Increase in diastolic pressure due to the displacement of volume.

Question 7

When the IAB inflates, it causes an increase in diastolic pressure, what is the benefit of this?

Answer 7

Increased coronary perfusion

Question 8

If the IAB inflates too EARLY, what can we assume?

Answer 8

Causes the following:
1.) Resistance to systolic ejection > Reduction of LV
emptying > ↓ Cardiac Output
2.) Greatly increased afterload.
3.) Premature closure of the Aortic Valve
4.) Increased cardiac workload and oxygen consumption

** DETRIMENTAL**

Question 9

If the IAB inflates too LATE, what can we assume?

Answer 9

Inflation would be late in the diastolic portion of the cardiac cycle, therefore; this limits

• Amount of augmentation that can be achieved
• Reduces coronary perfusion

Question 10

In relation to the IAB waveform, what are the following waveform characteristics from left to right at 1:1 ?

1. ) Upward wave #1
2. ) Upward wave #2
3. ) Downward wave #3
4. ) Upward wave #4

Answer 10

1. ) Unassisted Systole
2. ) Assisted diastolic augmentation
3. ) Assisted AEDP
4. ) Assisted Systole

Question 11

When the IAB deflates just prior to systole, there is a sudden decrease of pressure within the Aorta; this causes what?

Answer 11

1.) ↓ AEDP > ↓ Afterload = ↓Myocardial work, ↓ O2 consumption, ↑ Cardiac Output

Question 12

What does conventional timing refer to ?

Answer 12

Based on the duration of inflation during diastole, R to R interval on the EKG or peak to peak interval of the arterial pressure wave.

Question 13

Real timing of the IAB is based on?

Answer 13

Balloon deflation corresponding to systole.

Question 14

The delay between the QRS complex and the Aortic valve opening is called what?

Answer 14

Pre-ejection period (PEP)

[Relatively constant]

Question 15

The period of time between the opening and closing of the Aortic valve is referred to as?

Answer 15

Ejection Time (ET)

[Relatively constant]

Question 16

PEP + ET + ( ) = Contraction

Answer 16

Ventricular Diastole, the remaining period where changes with irregular rates and rhythms occur.

Question 17

1. ) How long does it take for the counterpulsation event to reach the subclavian artery?
2. ) How long does it take for the counterpulsation event to reach the Aortic Root?
3. ) Approximately, what is the total delay ?

4.) Therefore, how do you compensate for this delay when timing inflation of the IABP?

Answer 17

1. ) 25 msec
2. ) 25 msec
3. ) One small block (40 msec) on standard EKG paper at a speed of 25 mm/sec.

4.) Time inflation 1 block left of the dicrotic notch.

Question 18

How do you determine deflation of the IABP?

Answer 18

1.) Evaluate the Assisted AEDP, it should be less than
the Unassisted AEDP.
2.) Make sure the Assisted Systole following augmentation is less than

Question 19

Deflation, when using conventional timing is set to occur at ?

Answer 19

The End if Diastole during isovolumetric contraction

Question 20

REAL TIMING DEFLATION occurs at what point?

Answer 20

At each QRS complex

Question 21

EARLY Deflation results in ?

Answer 21

1. ) Lesser level Reduction in AEDP
2. ) Decreased Afterload Reduction
3. ) Retrograde flow in the Aorta > Angina

Question 22

LATE Deflation results in ?

Answer 22

Causes the IAB to remain inflated into the next systolic ejection, this causes the heart to work much harder.

1. ) ↑ Myocardial Work
2. ) ↑ MvO2
3. ) ↓ Cardiac Output

DETRIMENTAL

Question 23

What is the correct order in FRQUENCY RATIO WEANING?

Answer 23

1:1, 1:2, 1:3,

Question 24

What is VOLUME WEANING?

Answer 24

Volume decreased by a small portion 20-25% of the total volume. If tolerated, additional volume may be reduced NOT to go below 20% of its total volume.

Question 25

What type of weaning does NOT cause rapid changes in afterload reduction and therefore the heart is not required to respond to as with frequency ratio weaning?

Answer 25

Volume Weaning

Question 26

At what time frame should Heparin be stopped?

Answer 26

4 hrs. prior to removal