about iabp

1. Intra-aortic Balloon Pump
(IABP)
By David Kloda

2. 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

3. Background
 Preload
 Afterload
 Coronary flow
 Myocardial oxygen consumption in the
heart is determined by:
– Pulse rate
– Transmural wall stress
– Intrinsic contractile properties

5. Myocardial Oxygen
Consumption
 Has a linear relationship to:
– Systolic wall stress
– Intraventricular pressure
– Afterload
– End diastolic volume
– Wall thickness

7. 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

9. IABP in Myocardial Infarction
and Cardiogenic Shock
 Improves diastolic flow velocities after
angioplasty
 Allows for additional intervention to be
done more safely

10. 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

12. 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

13. 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

14. Contraindications to IABP
 Severe aortic insufficiency
 Aortic aneurysm

15. Insertion Techniques
 Percutaneous
– sheath less
 Surgical insertion

16. 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

18. Timing of Counterpulsation
 Electrocardiographic
 Arterial pressure tracing

20. Weaning of IABP
 Decreasing inotropic support
 Decreasing pump ratio

21. 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

22. 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

23. Cardiopulmonary Bypass
The heart lung machine
The pump
The bypass machine

24. 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

25. The Apparatus
 Pumps
– Simple roller pump
– Centrifugal pump
 Venous reservoir
 Oxygenator
 Heat exchanger
 Other

26. Venous Reservoir
 Siphons blood by gravity
 Provide storage of excess volume
 Allows escape of any air bubbles returning
with the venous blood

27. Oxygenator
 Provides oxygen to the blood
 Removes carbon dioxide
 Several types
– Bubble oxygenator
– Membrane oxygenator
– Microporous hollow-fiber oxygenators

28. Heat Exchanger
 Also called the heater / cooler
 Controls perfusate temperature
– Warm and cold

29. 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

30. 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

31. 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)

32. 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

33. Myocardial Protection
 Cold hyperkalemic solutions
– Produces myocardial quiescence
– Decreases metabolic rate
– Provides protection for 2-3 hours
– Blood vs. crystalloid

34. Termination of Perfusion
 Systemic rewarming
 Flowrates are decreased
 Hemodynamic parameters
 Venous line clamping
 Pharmacologic support
 Neutralization of heparin

35. Complications of Cardio-
Pulmonary Bypass
– Post perfusion syndrome
– Duration of bypass
– Age
– Anemia
– Other