Cardiac - Intraaortic Balloon Pumps

Question 1

Define counterpulsation in IABP therapy.

Answer 1

Inflation during diastole, deflation just before systole to assist cardiac output.

Question 2

What is the main goal of IABP therapy?

Answer 2

Increase myocardial oxygen supply and decrease myocardial oxygen demand.

Question 3

What gas is used in IABP and why?

Answer 3

Helium; low density allows rapid inflation/deflation and quick absorption if rupture occurs.

Question 4

Which researcher first described diastolic augmentation in animals?

Answer 4

Kantrowitz.

Question 5

How does IABP inflation affect diastolic pressure?

Answer 5

Increases diastolic pressure, improving coronary perfusion.

Question 6

What is the Diastolic Pressure Time Index (DPTI)?

Answer 6

A measure of myocardial oxygen supply enhanced by balloon inflation.

Question 7

What is the Tension Time Index (TTI)?

Answer 7

A measure of myocardial oxygen demand; reduced by balloon deflation.

Question 8

How does IABP deflation help reduce myocardial oxygen demand?

Answer 8

Reduces LV afterload at the start of systole.

Question 9

What ratio indicates improved myocardial viability with IABP?

Answer 9

Increase in DPTI/TTI ratio (Endocardial Viability Ratio, EVR).

Question 10

Name two absolute contraindications to IABP.

Answer 10

Aortic dissection; significant aortic regurgitation.

Question 11

How does aortic compliance affect IABP efficiency?

Answer 11

High compliance or low SVR reduces augmentation effectiveness.

Question 12

What are common complications of IABP?

Answer 12

Limb ischemia, thromboembolism, infection, balloon rupture.

Question 13

Why must the IABP balloon never be turned off while in situ?

Answer 13

Risk of thrombus formation inside the static balloon.

Question 14

When should you suspect juxta-renal positioning of the balloon?

Answer 14

If urine output falls after IABP insertion.

Question 15

What should be monitored during IABP therapy?

Answer 15

Timing of inflation/deflation, perfusion status, haemodynamics.

Question 16

What is the optimal IABP inflation point based on ECG?

Answer 16

Middle of the T wave (start of diastole).

Question 17

What happens with early inflation of the IABP?

Answer 17

Potential premature aortic valve closure; increased LV afterload.

Question 18

What happens with late inflation of the IABP?

Answer 18

Suboptimal coronary perfusion due to missed timing.

Question 19

What is the typical size of an IABP catheter?

Answer 19

8.0–9.5 French.

Question 20

How do you adjust balloon volume for patient height?

Answer 20

Smaller balloons for patients <152 cm; larger for >183 cm.

Question 21

Name two triggers used for IABP inflation.

Answer 21

ECG signal or arterial pressure waveform.

Question 22

What is the ideal position of the IABP tip?

Answer 22

2–3 cm distal to the origin of the left subclavian artery.

Question 23

Which vascular access site is most common for IABP?

Answer 23

Femoral artery.

Question 24

How is IABP weaning performed?

Answer 24

Gradual reduction of assist ratio (1:1 → 1:2 → off).

Question 25

Why is helium preferred over CO2 or air for balloon inflation?

Answer 25

Lower density; faster movement; safer absorption if rupture.

Question 26

What are risks associated with improper IABP deflation timing?

Answer 26

Reduced afterload unloading, impaired stroke volume.

Question 27

What is compartment syndrome in the context of IABP?

Answer 27

Ischemic limb complication due to balloon-related obstruction.

Question 28

What is the role of IABP in cardiogenic shock?

Answer 28

Temporary haemodynamic support until recovery or definitive therapy.

Question 29

In what cardiac surgery situation is IABP commonly used?

Answer 29

To assist weaning from cardiopulmonary bypass when LV function is poor.

Question 30

What arrhythmias can affect IABP function?

Answer 30

Atrial fibrillation; frequent ectopics; ventricular tachycardia.

Question 31

What haemodynamic effect does IABP have on preload and afterload?

Answer 31

Decreases both preload and afterload.

Question 32

What should you suspect with haemolysis during IABP use?

Answer 32

Mechanical RBC damage due to balloon action.

Question 33

What is diastolic augmentation in IABP waveforms?

Answer 33

Second pressure peak higher than native systolic pressure, representing balloon inflation.

Question 34

What major vascular complications are associated with IABP?

Answer 34

Aortic dissection, false aneurysm, bleeding.

Question 35

How does IABP assist during unstable angina?

Answer 35

Improves coronary perfusion, stabilises haemodynamics before PCI or surgery.

Question 36

How often should full blood count be checked during IABP use?

Answer 36

Twice daily to monitor haemoglobin and platelets.

Question 37

What parameter should be optimized during balloon insertion?

Answer 37

Correct balloon positioning relative to the aortic arch.

Question 38

Name two relative contraindications to IABP use.

Answer 38

Uncontrolled sepsis; severe peripheral vascular disease.

Question 39

What is the typical recommended anticoagulation approach with IABP?

Answer 39

Heparin infusion to prevent thrombosis.