2. PRELOAD
• Refers to the amount of stretch on the ventricular
myocardium prior to contraction.
• Starling’s law
Increase of volume in the ventricle at the end of diastole
results in increase in volume of blood pumped out
(cardiac output).
• Factors affecting preload
Aortic insufficiency
Circulating blood volume
Mitral valve disease
3.
4. AFTERLOAD
• Resistance that the heart must overcome in order to
eject the blood volume from the left ventricle.
• Factors affecting afterload
Aortic stenosis
Hypertension
5.
6. OXYGEN COMSUMPTION
Myocardial oxygen consumption depends
on,
Systolic wall stress
Intra ventricular pressure
Afterload
End diastolic volume
Wall thickness
7. INTRA AORTIC BALLOON PUMP
• Mechanical device that increases myocardial oxygen
perfusion while at the same time increases cardiac
output.
Cardiac output coronary blood flow
myocardial O2 delivery
•Temporary support for the left ventricle by
mechanically displacing blood within the aorta
9. WORKING OF IABP
A flexible catheter is inserted into the descending aorta.
A balloon is at the tip of the catheter.
When inflated, balloon blocks 85 – 90% of aorta. This balloon
displaces the blood in the aorta. This is known as counter
pulsation.
This sudden inflation moves blood superiorly and inferiorly to
the balloon.
When balloon is suddenly deflated, the pressure within the
aorta drops quickly.
10.
11. HELIUM
Low density
Easy to push in and pull out of the
balloon
Soluble
Helium will dissolve very quickly in
the blood if the balloon were to leak
some into the circulation.
12. IABP – INFLATION (diastolic augmentation)
• 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, and the aortic valve is
closed.
• The pressure wave that is created by inflation, forces blood
superiorly into the coronary arteries. This helps perfuse the
heart.
• Blood is also forced inferiorly increasing perfusion to distal
organs (brain, kidneys, etc.)
14. IABP – DEFLATION (systolic unloading)
• The balloon remains inflated throughout the
diastole.
• At the onset of systole, the balloon is rapidly
deflated. The sudden loss of aortic pressure
caused by deflation reduces afterload.
15. • The left ventricle does not have to
generate as much pressure to
achieve ejection since the balloon
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.
17. INDICATIONS
• Unstable angina
• Acute myocardial infarction
• Cardiogenic shock
• Complications of acute MI
• LV failure
• Adjunct to cardiac
catheterization
• Bridge to cardiac
transplantation
• High risk CABG – pre
and post OP
• Weaning from cardio
pulmonary bypass
18. CONTRA - INDICATIONS
ABSOLUTE
•Thoracic or abdominal
aortic aneurysm
•Occluded aorta
•Aortic stents
•Significant aortic
regurgitation
RELATIVE
• Severe aortic
insufficiency
• Severe peripheral
vascular disease
• Uncontrolled
sepsis
21. IABP – KIT CONTENTS
• Introducer needle
• Guide wire
• Vessel dilators
• Sheath
• IABP (34 or 40cc)
• Gas tubing
• 60 ml syringe
• 3 – way stop cock
22. BALLOON SIZING
BALLOON SIZE HEIGHT
50 cm3 > 6 feet
40 cm3 5 feet 4 inch to 6 feet
34 cm3 5 feet to 5 feet 4 inch
25 cm3 < 5 feet
Sizing based on patients height. 4 common sizes used.
Balloon length & diameter increases with larger size.
23. PRINCIPAL PARTS
A flexible catheter – 2 lumen
• For distal aspiration/ flushing or pressure
monitoring
• For periodic delivery and removal of helium
gas to a closed balloon.
A mobile console
• System for helium transfer with pump.
• Computer for control of the inflation and
deflation cycle.
24.
25. INSERTION TECHNIQUE
• Connect ECG.
• Set up pressure lines.
• Femoral access – followed by insertion of the
supplied sheath.
• J shaped guide wire to the level of the aortic arch.
• Take the entire catheter and T handle as one unit.
• Remove stylet/ aspirate/ flush.
26.
27. • Insert the balloon only over the guide wire.
• Hold the catheter close to skin insertion point.
• IABP should advance freely.
• Many vascular complications occur during insertion
itself.
• Resistance during insertion - dissection.
• Kinking of IABP results in improper inflation and
deflation
28. POSITIONING
• The end of the balloon
should be just distal (1-
2cm) to the take off of
the left subclavian
artery.
• Position should be
confirmed by CXR.
29. CONNECTING TO CONSOLE
• Connect helium gas tube to the console via a long
extender.
• Open helium tank.
• The central lumen of the catheter is flushed and
connected to pressure tubing with three way and
then to a pressure transducer to allow for
monitoring of central aortic pressure.
• Zero the transducer.
30.
31. INITIAL SETUP
• Once connected properly, the console would show
ECG and pressure waveforms.
• Make sure the setting is at auto mode.
32.
33.
34.
35. OPERATION MODES
AUTOMATIC TRACKS CARDIAC CYCLE, CARDIAC
RHYTHM AND ADJUSTS
AUTOMATICALLY.
SEMI-
AUTOMATIC
OPERATOR MUST ADJUST INFLATION
AND DEFLATION.
MANUAL OPERATOR MUST ADJUST INFLATION
AND DEFLATION , CAN SET FIXED RATE.
36.
37. TRIGGER
• Event the pump uses to identify the onset of cardiac cycle.
(systole)
• Pump must have consistent trigger in order to provide patient
assist.
• If selected trigger not detected, counter pulsation will be
interrupted.
ECG
The slope of QR segment to detect triggering points.
Arterial pressure wave
Systolic upstroke of arterial pressure waveform is the trigger.
38.
39.
40. During cardiac arrest, IABP can provide very
effective perfusion in conjunction with external
compression.
Since there is no ECG signal and no arterial
pressure wave to trigger the pump, an internal
trigger is selected.
This trigger detects the flow of blood caused by
compressions and inflates the balloon providing
improved circulations.
Good and consistent compressions are a must for
this to work.
42. INTRA AORTIC BALLOON COUNTERPULSATION
TIMING OF INFLATION
First identify the dicrotic notch.(when the aortic
valve closes)
43. If inflation is too early, the balloon inflates before the aortic
valve closes and pumps blood backward into the left
ventricle and increases left ventricular end diastolic volume
and left ventricular end diastolic pressure, increased left
ventricular wall stress or afterload and aortic regurgitation.
44. If inflation is too late, there will be sub optimal coronary
perfusion.
47. If deflation is too late, the balloon remains inflated too long, causing
increased afterload because the heart is trying to pump against inflated
balloon.
50. HOW TO CHECK WAVEFORM IS ACCEPTABLE?
• First change from 1:1 to 1:2 augmentation.
• Check dicrotic notch.
• See if augmentation starts at that point. This should
produce a sharp V at inflation.
• Check if diastolic augmented wave is > systolic wave.
• Confirm if end diastolic wave following the augmented
wave is less than an non-augmented wave.
51. MANAGEMENT AND MAINTENANCE CARE
• Anti coagulation – maintain apTT at 50 – 70s.
• CXR daily – to check IAB migration.
• Check lower limb pulses – 2 hourly.
• Ankle flexion and extension – 2 hourly.
If pulse not palpable – vascular obstruction, thrombus or
embolus.
• Hip flexion is restricted, head of the bed should not be
elevated beyond 30º.
• Use pressure relieving mattress.
52. • Change ECG electrodes daily.
• Change occlusive dressing daily.
• Secure balloon catheter at several points along the limb.
• Never leave in standby mode for more than 20 minutes –
thrombus formation.
• Check routine
Hb – risk of bleeding or hemolysis
Platelet count – risk of thrombocytopenia
Renal function – risk of AKI secondary to distal
migration of IABP catheter
• Wean off the IABP as early as possible as longer duration is
associated with higher incidence of limb complications.
53. OBSERVATIONS
• Observe hourly at catheter insertion site.
For signs of bleeding
Signs of infection
• If blood or brown dust is observed within the lumen,
immediately place the IABP in standby. The catheter
will have to be removed immediately.
• Check hourly for the radial pulse.
54. • Put SaO2 probe and check saturation.
• One hourly observe and record peripheral pulse,
capillary refill time, skin, temperature.
• Observe waveform to ascertain that the timing is
correct.
55. WEANING OF IABP
• Timing of weaning
oPatient should be stable for 24 – 48 hours.
• Decreasing inotropic support.
• Decreasing pump ratio
oFrom 1:1 to 1:2 to 1:3
• Decrease augmentation.
• Monitor patient closely
oIf patient becomes unstable, weaning should be
immediately discontinued.
56. IABP REMOVAL
• Discontinue heparin 6 hrs prior.
• Check platelet and coagulation factor.
• Deflate the balloon.
• Apply manual pressure above and below IABP insertion site.
• Remove balloon while alternating pressure above and below
insertion site to expel clots.
• Apply constant pressure to the insertion site for a minimum of
30 minutes.
• Check distal pulse frequently.
59. ECMO
• Technique of providing respiratory and cardiac
support; the blood is circulated through an
artificial lung consisting of two compartments
separated by a gas permeable membrane, with
the blood on one side and ventilating gas on the
other, it was originally used exclusively in new
borns but is now being used more and more in
adults.
60. • Instituted in an
emergency or
urgent situation
after failure of
other treatment
modalities.
• It is used as
temporary
support, usually
awaiting recovery
of organs.
61. PRINCIPLE
• Desaturated blood is drained via a venous
cannula.
• CO2 is removed, O2 is added through an “extra
corporeal” device.
• The blood is then returned to systemic circulation
via another vein (VV ECMO) or artery (VA
ECMO)
62.
63.
64. BRIDGING THERAPY
BRIDGE TO RECOVERY
Buying time for patient to
recovery.
BRIDGE TO DECISION
Provide temporary support to patients
and allow clinicians to decide on the next
step.
BRIDGE TO TRANSPLANT
Provide support to patient while
awaiting suitable donor organ.
66. VENO – ARTERIAL (VA ECMO)
• Used to support patients with
severe cardiac failure with or
without respiratory failure.
• Blood is drawn from a central vein,
pass through an ECMO machine
and then returned back via a
central artery. (usually femoral
artery & vein)
67. VENO – VENOUS (VV ECMO)
• Used to support patients with
severe respiratory failure
refractory to conventional
therapies. Provides
oxygenation. Only
respiratory support.
• Blood is drawn from a central
vein, pass through an ECMO
machine and then returned
back via a central vein.
68. CONFIGURATIONS OF VV ECMO
1. Femoro – Femoral
2. High flow
3. Femoro – Jugular
4. Double lumen - single cannula
In all cases, ECMO blood flow travels from vena cavae to the
atria (cavo – atrial) to minimise recirculation.
69. FEMORO – FEMORAL
Two long venous
cannulae are used.
Direction of flow is
cavo – atrial.
Access cannula is
inserted via the
femoral vein. Usual
sizes are 21 – 25F.
70. Return cannula is inserted via
the contra lateral femoral vein
with the tip sited within the right
atrium. Usual size 21 – 25 .
The tip of the access cannula is
positioned 10 – 15cm lower than
the tip of the return cannula to
minimise recirculation.
71. ADVANTAGES
• Quick and safe to insert.
• Easy to secure cannulae.
DISADVANTAGES
• Limited maximum flow rates so often
requires conversion to a high flow
configuration.
• Patient remains bed bound.
72. HIGH – FLOW
Uses the same bi-femoral
cannulation as Femoro –
femoral
An additional short access
cannula is inserted via the
right internal jugular vein
with the tip sited in the
superior vena cava.
Direction of flow is bi – cavo
atrial.
73. ADVANTAGES
• Allows higher circuit blood flow
as two access cannulae draw
patient blood from the great
veins.
• Can provide maximal oxygen
delivery if configured correctly.
DISADVANTAGES
• Occupies 3 veins. Complex to
secure and dress the jugular
cannula.
• Patient remains bed bound.
74. FEMORO – JUGULAR
Access cannula is inserted via
the femoral vein with the tip
sited just below the inferior
cavo – atrial junction. Usual
size is 21 – 25F.
Return short cannula is
inserted into the right internal
jugular vein with the tip sited
in the lower superior vena
cava. Usual size is 19 – 23F.
Direction of flow is cavo –
atrial.
75. ADVANTAGES
• Nearly can always provide
adequate support (5 – 7L/min)
without large recirculation.
• Only 2 veins occupied.
DISADVANTAGES
• Requires 2 sterile fields during
ECMO cannulation.
• Patient remains bed bound.
76. DOUBLE LUMEN – SINGLE CANNULA
Single cannula with 2 lumens for access and
return, inserted via the right internal jugular
vein.
Two access stages (SVC & IVC).
Return post emerges between 2 access ports.
Positioned at the level of tricuspid valve.
Direction of flow is bi – cavo atrial.
77.
78. ADVANTAGES
• Single vein
cannulation.
• Allows movement from
bed and potentially
ambulation.
DISADVANTAGES
• Care on insertion to
avoid right ventricular
placement or rupture.
• Difficult to position
return port towards the
tricuspid valve.
79. INDICATIONS
VA ECMO
• Cardiogenic shock – AMI &complications –
refractory to conventional therapy; IABP
• Post cardiac surgery – unable to wean
safely from cardio pulmonary bypass using
conventional supports.
• Drug overdose with profound cardiac
depression.
• Myocarditis
• Early graft failure - post heart lung
transplant
80. OTHER INDICATIONS
• Pulmonary embolism
• Massive haemoptysis/ pulmonary
haemorrhage
• Acute anaphylaxis
• Bridge to transplant
81. INDICATIONS
VV ECMO
• Severe pneumonia
• ARDS
• Acute lung failure
after transplant
• Pulmonary contusion
OTHER
• Smoke inhalation
• Status asthmaticus
• Airway obstruction
• Aspiration syndrome
Optimal ventilation
(consider
recruitment, prone,
inhaled prostacyclin)
PaO2/FiO2<60 or
PaO2/FiO2<100,
PaCO2>100mmHg>
1hr
83. INCLUSION CRITERIA
Presence of any 2 of the criteria from the following observed
over a period of 4 to 6 hours after maximum medical
resuscitation.
PaO2/FiO2 < 75%
Oxygen index > 40%
Murrays score > 3
a – A gradient > 600
Hypercapnia with pH < 7.2 observed over more
than 3 hours.
Lung compliance < 0.5 cc/cmH2O/kg
84. EXCLUSION CRITERIA
• Primary disease is irreversible (disseminated malignancy)
• Age > 75 years
• On ventilator > 15 days
• Irreversible / indeterminate neurological prognosis
• Immunosuppressed state
• Multi – organ failure
• Severe pulmonary HTN
• Severe aortic regurgitation
85. COMPLICATIONS
• Bleeding
• Thrombo embolism
• Cannulation related(perforation with bleeding, incorrect
location)
• Heparin induced thrombocytopenia
• Neurological complications (subarachnoid haemorrhage,
unexplained coma, brain death)
• Harlequin syndrome (asymmetric sweating and flushing on the
upper thoracic region of chest, neck, face.)
86.
87. ECMO TEAM
Two intensivists and/or cardio thoracic surgeons – cannulation
One medical officer – monitor cannula position by ECHO
One medical officer – clinical management
Perfusionist – ECMO priming & maintenance
Respiratory therapist – lung protective management, ventilator
settings
Nurses
Radiology technician
89. INITIATION
Once it has been decided to initiate ECMO,
the patient is anti coagulated with IV heparin
and cannulae are inserted according to
ECMO configuration.
Following cannulation, patient is connected
to ECMO circuit, the pump is started with the
flow of 20ml/kg/min and gradually
increased every 5 – 10 min by 10 ml/kg/min
to reach the desired flow.
Gas flow to blood flow ratio is adjusted to
0.5:1 & start with FiO2 of 21%to 100%.
Once the desired flow is achieved, ventilator
settings are brought down to baseline.
90. MAINTENANCE AND MONITORING
Once the initial respiratory and
hemodynamic goals have been achieved,
blood flow is maintained at that rate.
Continuous oximetry, pressure
monitoring (MAP, pre – pump P, pre &
post oxygenator P), vital parameters (HR,
RR, Temp), neurological status has to be
monitored.
Anti coagulation is sustained during
ECMO with a continuous infusion.
91. AVERAGE DAYS ON ECMO
VV ECMO – 14 to 21
days
VA ECMO – 5 to 14
days
92. DISCONTINUATION AND WEANING
For patients with respiratory failure;
improvements in CXR, pulmonary
compliance, arterial oxy – Hb saturation.
( gas exchange is able to be
maintained with a low FiO2<30%)
( RR & PEEP set on ventilator are
not too high: < 25bpm &
<15cmH2O respectively)
93. With cardiac failure; enhanced aortic pulsatility
correlates with improved left ventricular output.
( increasing blood pressure, return or increasing
pulsatility on arterial pressure waveform)
One or more trials of taking the patient off of ECMO
should be performed prior to discontinuing ECMO
permanently.
Early inflation will increase afterload as the heart must eject blood against the inflated balloon. This in turn will result in increased myocardial wall stress and left ventricular end diastolic pressure thereby increasing left ventricular work, reducing cardiac output.
If deflation is too early, there will be inadequate afterload reduction and sub optimal coronary perfusion.