Download Intra-Aortic Balloon Pump (IABP)

Intra-aortic Balloon Pump
(IABP)
By David Kloda
History

Realization that coronary perfusion mainly
occurs during diastole -1950s
 Aspiration of arterial blood during systole
with reinfusion during diastole decreased
cardiac work without compromising
coronary perfusion – Harkin-1960s
 Intravascular volume displacement with
latex balloons - early 1960s
Background

Preload
 Afterload
 Coronary flow
 Myocardial oxygen consumption in the
heart is determined by:
– Pulse rate
– Transmural wall stress
– Intrinsic contractile properties
Myocardial Oxygen
Consumption

Has a linear relationship to:
– Systolic wall stress
– Intraventricular pressure
– Afterload
– End diastolic volume
– Wall thickness
Indications for IABP

Cardiac failure after a cardiac surgical
procedure
 Refractory angina despite maximal medical
management
 Perioperative treatment of complications
due to myocardial infarction
 Failed PTCA
 As a bridge to cardiac transplantation
IABP in Myocardial Infarction
and Cardiogenic Shock

Improves diastolic flow velocities after
angioplasty
 Allows for additional intervention to be
done more safely
IABP During or After Cardiac
Surgery

Patients who have sustained ventricular
damage preoperatively and experience
harmful additional ischemia during surgery
 Some patients begin with relatively normal
cardiac function an experienced severe, but
reversible, myocardial stunning during the
operation
IABP As a Bridge to Cardiac
Transplantation

15 to 30 % of endstage cardiomyopathy
patients awaiting transplantation need
mechanical support
 May decrease the need for more invasive
LVAD support
Other Indications for IABP

Prophylactic use prior to cardiac surgery in
patients with:
– Left main disease
– Unstable angina
– Poor left ventricular function
– Severe aortic stenosis
Contraindications to IABP

Severe aortic insufficiency
 Aortic aneurysm
Insertion Techniques

Percutaneous
– sheath less

Surgical insertion
Positioning

The end of the balloon should be just distal
to the takeoff of the left subclavian artery
 Position should be confirmed by
fluoroscopy or chest x-ray
Timing of Counterpulsation

Electrocardiographic
 Arterial pressure tracing
Weaning of IABP

Decreasing inotropic support
 Decreasing pump ratio
Complications

Limb ischemia
– Thrombosis
– Emboli

Bleeding and insertion site
– Groin hematomas





Aortic perforation and/or dissection
Renal failure and bowel ischemia
Neurologic complications including paraplegia
Heparin induced thrombocytopenia
Infection
IABP Removal







Discontinue heparin six hours prior
Check platelets and coagulation factors
Deflate the balloon
Apply manual pressure above and below IABP
insertion site
Remove and alternate pressure to expel any clots
Apply constant pressure to the insertion site for a
minimum of 30 minutes
Check distal pulses frequently
Cardiopulmonary Bypass
The heart lung machine
The pump
The bypass machine
History

Concept of diverting the circulation to an
extracorporeal oxygenator – 1885
 Mechanical pump oxygenators – 1953
 Controlled cross circulation – 1954
 First series of intracardiac operations using
a pump oxygenator – 1955
The Apparatus

Pumps
– Simple roller pump
– Centrifugal pump

Venous reservoir
 Oxygenator
 Heat exchanger
 Other
Venous Reservoir

Siphons blood by gravity
 Provide storage of excess volume
 Allows escape of any air bubbles returning
with the venous blood
Oxygenator

Provides oxygen to the blood
 Removes carbon dioxide
 Several types
– Bubble oxygenator
– Membrane oxygenator
– Microporous hollow-fiber oxygenators
Heat Exchanger

Also called the heater / cooler
 Controls perfusate temperature
– Warm and cold
Cardiopulmonary Bypass

Heparinization
 Total bypass
 Partial bypass
 Flowrates 2-2.5 l/min. per square meter
– Flowrates depend on body size
– Flowrates depend on cannula sizes

Hypothermia
Shed Blood

Is aspirated with a suctioning apparatus,
filtered and return to the oxygenator
 A cell saving device may also be utilized
during and after bypass
Blood Pressure

Decreases sharply with onset of bypass
(vasodilatation)
 Mean arterial pressure needs to the above
50-60 mm Hg.
 After 30 minutes perfusion pressure usually
increases (vasoconstriction)
Oxygen and Carbon Dioxide
Tensions

Concentrations are periodically measured in
both arterial and venous lines
 Arterial oxygen tension should be above
100 mm Hg
 Arterial carbon dioxide tensions should be
30-35 mm Hg
 A drop in venous oxygen saturation
suggests underperfusion
Myocardial Protection

Cold hyperkalemic solutions
– Produces myocardial quiescence
– Decreases metabolic rate
– Provides protection for 2-3 hours
– Blood vs. crystalloid
Termination of Perfusion

Systemic rewarming
 Flowrates are decreased
 Hemodynamic parameters
 Venous line clamping
 Pharmacologic support
 Neutralization of heparin
Complications of CardioPulmonary Bypass
– Post perfusion syndrome
– Duration of bypass
– Age
– Anemia
– Other