iabp when , why and how ?

When to use this !

Ongoing ischemia refractory to medical therapy.

Prophylactic placement for high-risk patients with critical coronary

disease

High-risk patients undergoing off-pump surgery to maintain

hemodynamic stability during lateral wall or posterior wall grafting.

Unloading for cardiogenic shock or mechanical complications of

myocardial infarction (acute mitral regurgitation, ventricular septal

rupture).

Postcardiotomy low cardiac output syndrome unresponsive to

moderate doses of multiple inotropic agents.

Postoperative myocardial ischemia.

Acute deterioration of myocardial function to provide temporarysupport or serve as a bridge to transplantation.

*2 Primary Benefits of IABP

The primary purpose of the IABP is to increase Coronary

Oxygen Supply during Diastole.

The next purpose of the IABP is to Decrease Coronary

Oxygen Demand during Systole.

*Secondary Benefits of IABP

Decreased Heart Rate

Decreased Blood Pressure

Increased Cardiac Output.

Superior

Vena

Cava

Inferior

Vena

Cava

Aorta

Pulmonary

Artery

Right

Atrium

Left

Atrium

Right

Ventricle

Left

Ventricle

Blood

moves by

pressure

gradient

Inferior

Vena

Cava

Cardiac Anatomy

Cardiac Output = Stroke Volume x Heart Rate

normal: 4 – 8 L/min

Cardiac Index =

normal: 2.5 – 4.0 L/min/m 2

CO

BSA

Hemodynamics

CO = HR x SV

HRSinus Node

Endocrine

CNS

Baroreceptors

SV

Preload

Afterload

Contractility

Myocardial Oxygen Balance

Preload

Afterload

Heart Rate

Contractility

O2 Extraction

Diastolic Time

Diastolic Pressure

Coronary Artery Flow

Demand Supply

Principle of Counterpulsation

*Counterpulsation

Synchronization of the pumping of the IABP with diastole

(Inflation) and Systole (Deflation) is called

counterpulsation.

Balloon Placement

To pump

Left Subclavian

Descending

Thoracic

Aorta

Kidney

Deflated Inflated

90%

Occlusive

IAB OCCLUSIVITY

Balloons exert their hemodynamic effect by

volume displacement

*Inflation during Diastole

The primary purpose of the IABP is to increase Coronary Oxygen

Supply during Diastole.

Benefits of Inflation

• Increased coronary blood flow

• Increased diastolic pressure

• Potential for increased coronary

collateral circulation

• Increased systemic perfusion

Deflation at Onset of Systole

*Deflation During Systole

The next purpose of the IABP is to Decrease Coronary Oxygen

Demand during Systole

Benefits of Deflation

• Decreased Afterload

• IVC Phase Shortened

• Increased Stroke Volume

• Enhanced Forward Cardiac

Output

Signs of Improved Clinical Condition

Increased cardiac output, 0.5 – 1 L/min

Increased urine output

Decreased preload

Decreased pulmonary congestion

Improved mentation

Decreased heart rate

Decreased lactic acidosis

Increased pulse pressure and pulse rate

Inflation Deflation

ECG

Electrical Event

Arterial

Pressure

Mechanical Event

Cardiac Cycle

Absolute Contraindications

• Aortic Insufficiency

• Dissecting Aortic Aneurysm

Relative Contraindications

• End-Stage Cardiomyopathy in a patient not

a candidate for transplant

• End-stage Terminal Disease

• Abdominal Aortic Aneurysms, not resected

Complications

Increased Complication Risk

PVD

Female Gender

Diabetes

Hypertension

Nicotine Use

Obesity

Shock

SVR

Complications

Aortic WallDissection

Rupture

Local Vascular Injury

EmboliThrombus

Plaque

Air

Complications

IAB RuptureHelium Embolus

Catheter Entrapment

Compromised circulation due to catheter

– Limb ischemia– compartment syndrome

In nearly all circumstances the IABP will be inserted via the Femoral

Artery.

Pre-Insertion Assessment

1. Skin color of both legs

2. Skin temperature of both legs

3. Capillary refill ability of both legs

4. Quality of pulses in both arms & legs

5. Baseline sensation and movement of both legs

6. Complete neuro check

Adult IAB Sizing Recommendations

DiastoleSystole

<162cm

<5’4”

<1.8m2

<182cm

<6’0”

>1.8m2

>182cm

>6’0”

Height

BSA

30cc 40cc 50cc

Access Femoral Artery

May be done

with or

without a

syringe

Timing

How is proper timing achieved?

• Always performed using the arterial

pressure waveform as the guide

Arterial Pressure Waveform

PSP

Dicrotic Notch

PSP

Dicrotic Notch

AVOAVO

AEDP

IVC

25% SV75% SV

XX

Patient

Aortic

End

Diastolic

Pressure

Dicrotic

Notch

Assisted

Peak

Systolic

Pressure

Peak

Systolic

Pressure

Balloon

Aortic End

Diastolic

Pressure

Augmentation

APSP

AUG

PSP

PAEDP

BAEDP

DN

Arterial Pressure Waveform

Without IABP

With IABP

assist 1:2

Assist Ratios

1:1

1:2

1:3

DN DN

Correct Inflation: Just prior to DN

When inflation timing is correct there

should be a sharp “V” shape at the

dicrotic notch.

Augmentation should be higher than PSP unless:

1. Patient’s SV significantly greater than

balloon volume

2. Balloon is positioned too low

3. Hypovolemia

4. Balloon is too small

5. Improper timing

6. Partial obstruction of gas flow

PSP AUG

APSP < PSP

CORRECT DEFLATION : BAEDP < PAEDP

PSPAPSP

BAEDP

PAEDP

Timing Errors

• Early Inflation

• Late Inflation

• Early Deflation

• Late Deflation

Early Inflation

Early Inflation Correct Timing

move inflation

AUG

DN

Late Inflation

Late Inflation Correct Timing

move inflation

AUG

DN

Early Deflation

Early Deflation Correct Timing

move deflation

PSP APSP

Late Deflation

Late Deflation Correct Timing

move deflation

BAEDP

PAEDP

# 1

Inflation is Good

Deflation is early

# 2

Inflation Is early

Note that the Dicrotic Notch on inflation appears higher than

non-inflation

Deflation is normal

# 3

Inflation is Good

Deflation is Good

# 4

Appears Good but we really cannot make comparisons on 1:1

timing.

# 5

Inflation is Early

Deflation is Early

# 6

Inflation is late

Deflation is good

Helium Delivery

Balloon Inflation

0

transducer

pumphelium

BPW

compressor

Vacuum /

compressor

system

Balloon Deflation

0

transducer

pumphelium

BPW

vacuum

Vacuum /

compressor

system

Heart Rate Variations

BPW in Irregular Diastole (Afib)

Pressure Variations

Fill Failure

Pump did not fill adequately with helium to establish the

balloon pressure waveform baseline

Verify helium tank not empty, all catheter connections intact

Gas Loss

0

300

Classic BPW of an IAB too large for the aorta

Triggering

Definition

Options

FOR GOOD, CONSISTANT TRIGGERING IT IS IMPORTANT TO

PROVIDE THE PUMP WITH A GOOD ECG SIGNAL

Good Choices –

Unidirectional QRS with minimal

artifact

Poor Choices –

Biphasic QRS, tall T or P waves, wandering baseline, artifact

present

This lead will give you both

triggering and timing problems

ECG

Newer Systems will automatically initiate

Arrhythmia Timing when several irregular

diastolic intervals occur.

Arrhythmia Timing allows for more

consistent and appropriate deflation of the

IAB during irregular rhythms.

Timing with Irregular Rhythms

Arrhythmia Timing

Conventional Timing

V Pacer

Arterial Trigger

The IABP will detect changes in arterial pressure to

initiate inflation and deflation.

It is the trigger of choice when CPR is in progress.

Internal

The balloon inflates and deflates at a

preset rate regardless of the patient’s

cardiac activity.

This mode is only to be used when there

is no cardiac output and no ECG but

many newer systems can detect pressure

differences from CPR

Cardiac Arrest

What do you do with the IABP?

Augmentation

Augmentation refers to how full we fill the IABP balloon during operation.

During normal operation the IABP will be operated at 100% augmentation

The IABP should never be operated below 50% augmentation.

Low augmentation can result in the peak diastolic

augmentation being lower than unassisted systole and

the wave form will look irregular.

Augmentation is frequently used in conjunction with

timing to wean the patient from the IABP.

Other Complications Of IABP

Balloon Rupture

Balloon Rupture can allow a large gas embolism to enter the body.

The IABP must never be operated if a Balloon rupture is suspected.

The classic sign of a balloon rupture is rust colored specs inside the

IABP helium tubing in conjunction with loss of helium pressure.

It the rupture is large it may be RED.

Gas Loss

Transducer Position

The transducer should be placed in line with the phlebostatic axis.

During transport it is critical that the transducer be secured at a fixed

point on the patient.

For every inch variance to the phlebostatic axis there is a 2 mm/HG

inverse change in pressure.

Increase height by 4 inches and pressure reads 8 mm/HG lower

All of the transducer connections must be tight to prevent rapid

blood loss.

There must not be any air in the transducer lines.

weaning

Criteria for weaning

Ratio , augmentation and heparin

weaning

IABP support can be withdrawn when the cardiac output is satisfactory

on minimal inotropic support (usually 1 mg/min of epinephrine or 5

mg/kg/min of either dopamine or dobutamine). However, earlier

removal may be indicated if complications develop, such as leg

ischemia, balloon malfunction, thrombocytopenia, or infection.

weaning

Weaning is initiated by decreasing the inflation ratio from 1:1 to 1:2

for about 2– 4 hours, and then to 1:3 or 1:4 for 1–2 more hours.

Once it is determined that the patient can tolerate a low inflation

ratio with stable hemodynamics, the IABP should be removed.

If there is an anticipated delay in removal of more than a few hours

for manpower reasons or because of the need to correct a

coagulopathy, the ratio should be increased to at least 1:2 to

prevent thrombus formation.

Removal of the ballon

Hussein Khairy ElkhayatLecturer (consultant) of Cardiothoracic Surgery

Faculty of Medicine, Assiut university,

Assiut,Egypt.

P.Box 71526

Mobile : + 2 010 0 55 49 6 53

Work : + 2 088 241 37 73

Fax : +2 088 2333327

Website: http://www.aun.edu.eg/membercv.php?M_ID=4489

For more information , please contact me : dr_khayat@Hotmail.com

Thank you