• Briefly, outline the concepts behind intra-aortic balloon counterpulsation (IABCP)
  • Identify the points labelled A-F on the following intra-aortic balloon pump pressure-time trace?

  • What methods can be used to check that the IABCP catheter is in the correct position, both during and after insertion?
  • What methods can be used to trigger the IABCP?
  • Blood is seen in the tubing connected to the gas lumen of the IABCP catheter. What problem do you suspect, and what action should be taken? 

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College Answer

a) Concepts behind intra-aortic balloon counterpulsation (IABCP)

Classic concept of intra-aortic balloon counter pulsation involves inflation in synchrony with aortic valve closure at the onset of isovolumic diastole and the appearance of the dicrotic notch

This displaces blood comparable to the balloons volume into the peripheral circulation during diastole

To accomplish further unloading and to prevent interference with left ventricular ejection, balloon deflation starts prior to opening of the aortic valve and the onset of LV ejection

The classic response is thus is a lowering of the systolic pressure and augmentation of the diastolic pressure

The main benefits are a decrease in afterload and increased coronary artery perfusion with secondary improvements in hemodynamics

b)

A = Assisted systole

B = Diastolic augmentation

C = Unassisted systole

D = Unassisted aortic end-diastolic pressure

E = Dicrotic notch

F = Assisted aortic end-diastolic pressure

  • Methods
  • Image intensifier screening during insertion
  • Length of catheter inserted should be distance from insertion point to umbilicus, plus distance from umbilicus to sternal angle
  • Position on TOE should be 2 cm distal to L subclavian
  • CXR to confirm position - Just above the level of the left main bronchus or 2nd or 3rd intercostal space

e) Methods can be used to trigger the IABCP

  • ECG
  • BP
  • Pacing

e) Problem

• Balloon rupture should be suspected. IABCP catheter should be disconnected from console. It should then be removed (and replaced if it is still needed).

Discussion

IABP is discussed in greater detail elsewhere.

  • Briefly, outline the concepts behind intra-aortic balloon counterpulsation (IABCP)
    • The balloon inflates in diastole, displacing aortic blood both into the systemic circulation and into the coronary arteris.
    • The ballon deflates before systole, decreasing aortic pressure
    • Diastolic augmentation thus improves coronary blood flow
    • Systolic augmentation this decreases afterload and LV workload
  • Identify the points labelled A-F on the following intra-aortic balloon pump pressure-time trace?

labelled diagram of IABP trace

  • What methods can be used to check that the IABCP catheter is in the correct position, both during and after insertion?
    • Measurement of the length of insertion: from insertion point to umbilicus, plus distance from umbilicus to sternal angle
    • Fluoroscopy-guided insertion
    • TOE
    • CXR

Alternatively (and dangerously) one can retract the IABP until it no longer causes diminished left subclavian bloodflow.

  • What methods can be used to trigger the IABCP?
    • Blood pressure
    • ECG
    • Pacemaker
  • Blood is seen in the tubing connected to the gas lumen of the IABCP catheter. What problem do you suspect, and what action should be taken?
    • This means the balloon has ruptured. The IABP tends to stop pumping on its own when this happens - loss of helium pressure triggers the off-valve. The next step is to remove it.

References

References

Insertion of the IABP: a manual by MAQUET

Moulopoulos, Spyridon D., Stephen Topaz, and Willem J. Kolff. "Diastolic balloon pumping (with carbon dioxide) in the aorta—a mechanical assistance to the failing circulation." American heart journal 63.5 (1962): 669-675.

SOROFF, HARRY S., et al. "Assisted circulation II. Effects of counterpulsation on left ventricular oxygen consumption and hemodynamics." Circulation 27.4 (1963): 722-731.

Hanlon-Pena, Patricia M., and Susan J. Quaal. "Intra-aortic balloon pump timing: review of evidence supporting current practice." American Journal of Critical Care 20.4 (2011): 323-334.

Krishna, Murli, and Kai Zacharowski. "Principles of intra-aortic balloon pump counterpulsation." Continuing Education in Anaesthesia, Critical Care & Pain9.1 (2009): 24-28.

Nanas, J. N., and S. D. Moulopoulos. "Counterpulsation: historical background, technical improvements, hemodynamic and metabolic effects." Cardiology 84.3 (1994): 156-167.