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An intra-aortic balloon pump (IABP) is an electrocardiogram (ECG)
synchronized endovascular balloon that inflates in the proximal
descending aorta (Figure 40-1) during cardiac diastole, acting both
to augment coronary perfusion and cardiac output, and deflates during
systole, permitting cardiac ejection.
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Definitions and Terms
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- ▪ Counterpulsation: Rhythmic mechanical pumping synchronized
with the heartbeat.
- ▪ Systole: The phase of the heartbeat during which cardiac
muscle contracts actively ejecting blood through the open aortic
valve.
- ▪ Diastole: The phase of the heartbeat during which the left
ventricle fills with blood from the left atrium through the open
mitral valve, and during which the majority of coronary perfusion
occurs.
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- ▪ Indications:
- —Unstable angina
- —Cardiogenic shock
- —Cardiac insufficiency following cardiac surgery
- —Mechanical cardiac support in the setting of certain
cardiac lesions such as acute mitral insufficiency or intracardiac
shunt
- ▪ Contraindications:
- —Aortic dissection
- —Aortic insufficiency
- —Severe atherosclerotic disease of the aorta
- —Aortic aneurysm
- —Aortic graft
- ▪ Prior to procedure, obtain patient consent, prep and
drape, and perform universal protocol as described in Section I.
- ▪ The IABP is almost invariably placed through one of the
femoral arteries.
- ▪ Preparation:
- —Skin: The Center for Disease Control and Prevention
(CDC) recommends preparation of the cannulation site with a 2% aqueous
chlorhexidine-gluconate solution, which has been associated with
lower blood stream infection rates than povidone-iodine or alcohol-based
preparations. The skin and tissue around the vessel should be infiltrated
with 1% lidocaine solution, except in patients with a known
allergy to lidocaine, in whom alternative local anesthetics can
be used.
- —Hygiene: The operator should observe proper hand-hygiene
and use maximal barrier precautions including gown, mask and gloves,
and a large sterile drape or multiple drapes covering a large area.
- ▪ Methods (see Chapter 34 on vessel cannulation):
- —Direct cannulation.
- —Transfixion.
- —Seldinger technique is used as an adjunct for catheter
exchange with either of the above cannulation techniques.
- —Ultrasound guided vessel location can be used for
femoral cannulation.
- ▪ Following access to the vessel, the IABP is inserted
to a premeasured depth so as to lie in the proximal descending aorta
(Figures 40-2, 40-3, 40-4, and 40-5).
- ▪ Balloon inflation is timed to occur during diastole, and
gated to the ECG or arterial pulse wave (Figure 40-6).
- ▪ The pumping ratio is typically 1:1, although it may be
reduced to 1:2 and/or 1:3 prior to removal.
- ▪ A confirmatory chest x-ray is used to identify the location
of the tip of the balloon.
- ▪ Complications are varied, and include:
- —Leg ischemia or compartment syndrome
- —Aortic dissection
- —Embolization of debris to the brain and/or
visceral organs
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