P2portal

IABP

Intra Aortic Balloon Pump or Intra aortic balloon counter pulsation
A flexible catheter is inserted into the femoral artery and passed into the descending aorta.
Temporary support for the left ventricle by mechanically displacing blood within the aorta.
Increases myocardial oxygen perfusion while at the same time increasing cardiac output.
Increasing cardiac output increases coronary blood flow and therefore myocardial oxygen delivery.
Correct positioning is critical in order to avoid blocking off the subclavian, carotid, or renal arteries.

Preload: The ventricular wall tension at the end of diastole that often approximated by the end-diastolic volume or end-diastolic pressure. (referred to as filling pressure)
Afterload: The ventricular wall tension during contraction; the resistance that must be overcome in order for the ventricle to eject its contents that often approximated by the systolic ventricular (or arterial) pressure.
Stroke Volume: Volume of blood ejected from the ventricle in systole (= end-diastolic volume - end-systolic volume).
Cardiac Output: Volume of blood ejected from the ventricle per minute (= stroke volume X heart rate).

Inflation of the balloon occurs at the onset of diastole. At that point, maximum aortic blood volume is available for displacement because the left ventricle has just finished contracting and is beginning to relax, the aortic valve is closed, and the blood has not had an opportunity to flow systemically.
The pressure wave that is created by inflation forces blood superiorly into the coronary arteries that helps perfuse the heart.
Blood is also forced inferiorly increasing perfusion to distal organs (brain, kidneys, tissues, etc.)
The balloon remains inflated throughout diastole. At the onset of systole, the balloon is rapidly deflated.
The sudden loss of aortic pressure caused by the deflation reduces afterload so:
- The left ventricle does not have to generate as much pressure to achieve ejection since the blood has been forced from the aorta.
- This lower ejection pressure reduces the amount of work the heart has to do resulting in lower myocardial oxygen demand.

A flexible catheter (2 lumen) with a balloon (cylindrical polyethylene) at the distal tip
- for distal aspiration/flushing or pressure monitoring
- for the periodic delivery and removal of helium gas to a closed balloon.

A mobile console containing a pump
- system for helium transfer
- computer for control of the inflation and deflation cycle

The shaft of the balloon catheter contains 2 lumens:

one allows for gas exchange from console to balloon

second lumen:

Balloon is made of a long polyurethane membrane mounted on a vascular catheter (10-20 cm)
Various catheter sizes - usually 7.5 F with the balloon size chosen according to height (25–50cc capacity)
May be sheathed or sheath-less
Optimal 80-90% of aorta occluded (not 100%)
Helium is used to inflate the balloon as its low viscosity means there is little turbulent flow so the balloon can inflate fast and deflate slowly. It is also relatively benign and eliminated quickly if there is a leak or the balloon ruptures

Based on patients height, Balloon length and diameter increases with each larger size
Pediatric balloons also available : sizes 2.5, 5.0, 12.0 and 20 cm³