CARDIOPULMONARY BYPASS ;;FOR PERFUSION STUDENTS.

1. MANU JACOB
PERFUSIONIST
KMCT MCH

4. Cardiopulmonary bypass is the diversion of the flow of
blood to the aorta, via a pump& oxygenator; avoiding
both the heart & lungs

9. GOALS OF CPB
• Oxygenation and carbon dioxide elimination
• Circulation of blood
• Systemic cooling and re-warming
• Diversion of blood from the heart to provide
a bloodless surgical field

11. COMPONENTS OF CPB

12. Operational Parts of CPB
1. Pump Takes over the function of heart
2. Oxygenator Gas exchange function of lung
3. Circuits Direct venous blood to
oxygenator and return to
systemic circulation.
4. Prime Fluid used to prime oxygenator
and circuits prior to CPB

13. Scheme of CPB Circuit
• Pump
• Oxygenator
• Heat exchanger
• Reservoir
• Filter
• Sucker & vent
• Cardioplegic solution
delivery system

14. Venous blood is intercepted as it returns
to the RA and diverted through the
venous line of the CPB circuit to a
venous reservoir.
Cardiopulmonary Bypass

15. Cardiopulmonary Bypass
The arterial pump functions as an artificial heart
by withdrawing blood from the reservoir and
propelling it through a heat exchanger, an
artificial lung (the oxygenator), and an
arterial line filter before returning it through
the arterial line to the patient's arterial
system.

16. Additional pumps and components are used to
assist in the operation to manage shed blood
(the pump sucker), decompress the heart
(vent), and deliver cardioplegia solution
Cardiopulmonary Bypass

17. • The CPB circuit performs the function of
heart and lungs
• The blood is drained from the right side of
the heart and returned to the systemic
circulation through the aorta
Cardiopulmonary Bypass

18. Blood Tubing
• The tubing used to connect the various
components and divert blood into and out of
the patient's vascular system
• Newer generation of PVC tubing has surface
coating with heparin

19. TUBINGS
• The tubings which
are used for CPB
are made of PVC’s.
• There are 4
standard tubing
sizes which are
commonly used on
CPB circuit.
• a)3/16” b) ¼” c)
3/8” d) ½”

20. TUBINGS
• According to the
height and weight of
the patient the size
of the tube varies.
• The length of the
tubing should be as
minimum as
possible, which
reduces the priming
volume and
haemolysis.

21. Venous Reservoirs
• Positioned between
the venous line and
the arterial pump
• Blood reservoirs may
be clear plastic hard-
shelled containers.
• Accomodates large
volume of blood out
of the circulation

22. Arterial Pumps
• The pumping device used to replace the
function of the heart
• Two primary technologies: a roller pump or a
centrifugal pump

23. Arterial Pumps
Both pump technologies are traumatic to the
blood cells; however centrifugal pumps are
thought to be less traumatic than roller
pumps

25. Roller pumpsRoller pumps are positive-
displacement pumps that
function by occluding a point
in a piece of tubing and then
rolling the occlusive point of
contact along a length of the
tubing. This forces the fluid in
the tubing to move forward
in front of the occlusive point
while simultaneously drawing
in fluid behind the occlusive
point.

26. Centrifugal pumps
Centrifugal pumps, in contrast, are
nonocclusive kinetic pumps that generate
flow by magnetically coupling the high-speed
revolution of a reusable motor to the plastic
plates, fins, or channels inside a disposable
cone.

27. Centrifugal pumps
• Centrifugal pumps, in
contrast, are nonocclusive
kinetic pumps that
generate flow by
magnetically coupling the
high-speed revolution of
a reusable motor to the
plastic plates, fins, or
channels inside a
disposable cone.

29. Heat Exchanger
• Facilitate management of the patient's blood
temperature
• The heat exchangers may be used to reduce
the temperature of the blood on initiation of
CPB and then to warm the blood before the
termination of CPB.
• Reduces the temperature of the cardioplegia
blood to the required level

31. Oxygenator
The oxygenator substitutes for the patient's
native lungs and performs the essential
function of gas exchange.

34. Oxygenator
• Oxygen and CO2 diffuses
across a membrane in
the oxygenator. The
membrane is usually
made from microporous
polypropylene.
• The oxygenator has
separate gas inlet and
outlet ports

35. Arterial Line Filter
These filters are
placed in the arterial
line as the last
component through
which blood passes
before it returns to
the patient.

36. Arterial Line Filter
With pore sizes of
20 to 40 µm,
arterial line filters
increases patient
safety by removing
particulate and
gaseous
microemboli.

37. Management before
Cardiopulmonary Bypass
• Anticoagulation
• Cannulation of the heart
• Careful monitoring
• Protection of the heart
• Preparation for cardiopulmonary bypass

38. Physiologic parameters of CPB
• Perfusion pressure
• Pump flow
• Temperature management
• Central nervous system monitoring
• Pulsatility

39. Sequence of Events
• Circuit selection and priming
• Anticoagulation
• Cannulation
• Initiation and maintenance of CPB
• Myocardial protection
• Weaning and termination from CPB.

40. Fluid Management
• Crystalloid solutions lead to decreased
colloid osmotic pressure with a resultant
increase in extracellular water retention,
irrespective of the osmolarity of the pump
prime.
• Albumin, can decrease the interaction of
blood components with the bypass circuit by
coating the fluid pathway surfaces

41. Priming
• “prime volume” is the volume of balanced
electrolyte solution necessary to completely
de-air the circuit
• Main cause of the hemodilution associated
with CPB
• This increased volume of distribution dilutes
all of the proteins, coagulation factors and
formed elements of the blood
• Dilutes plasma levels of drugs

42. Anticoagulation
• Heparin is a heterogeneous, heavily sulfated
polysaccharide compound derived from pig
intestinal mucosa or bovine lung.
• It binds antithrombin III, profoundly
facilitating its native ability to inhibit plasma
coagulation, most prominently through
inhibition of factors IIa (thrombin) and Xa

43. Anticoagulation
• Anticoagulation with heparin for CPB can be
monitored by measuring clotting times or
whole blood heparin concentrations
• Most commonly test used for CPB are the ACT
• Heparin resistance: AT III concentrate or FFP

44. Protamine, a polycationic protein derived
from salmon sperm contains two active
sites
– It neutralizes heparin
– It exerts a mild anticoagulant effect independently
of heparin
Anticoagulation

46. CANNULAS
• The cannulas are the catheters which
are used to connect the patients
circulation to the extracorporeal circuit.
• There are three types of cannulations
involved in CPB.
– Arterial,
– Venous
– Cardioplegia cannulation.

47. Cannulation
• The target for venous cannulation is generally
the RA.
• Target for the arterial cannula is ascending
aorta
Aortic
Cannulas

48. Cannulation
• The target for venous cannulation is generally
the RA.
• Target for the arterial cannula is ascending
aorta
Aortic
Cannulas

49. Arterial Cannulation
• Oxygenated blood is returned to the
patient via the arterial cannulae.
• Before arterial cannulation heparin is given
IV. 1st dose: 3mg/ kg to achieve an ACT above
480 seconds.
• Anticoagulation is monitored by ACT at
regular intervals and supplementary doses
given according to the requirements.

52. Venous Cannulation
• Systemic venous blood is diverted to the
oxygenator through two flexible plastic
cannulae which are inserted into the superior
and inferior venacavae.
• Otherwise a single cannulae inserted into RA
through RA appendage.

53. Venous Cannulation
• There are two types of
venous cannulation.
– Single stage venous
cannulation: Cannula is
inserted directly into the IVC
and SVC
– Double stage venous
cannulation: inserted into the
RA

54. Venous Cannulation
Blood flows freely into
the oxygenator under
the influence of
Gravity Siphon.

55. CARDIOPLEGIA CANNULA
THESE
CANNULAS ARE
USED TO
DELIVER
CARDIOPLEGIA
TO THE PATIENTS

56. Myocardial Protection
• To provide a motionless field for the surgeon,
the heart is arrested in diastole by the
administration of a potassium-enriched
cardioplegia solution to the heart.
• Potassium-induced arrest alone reduces the
heart's myocardial oxygen consumption by
90%.

57. Myocardial Protection
• The combined influence of potassium arrest
and myocardial temperatures lower than
22°C reduces myocardial oxygen
consumption by 97% and enables the tissue
to withstand complete interruption of blood
flow for periods of 20 to 40 minutes

59. CARDIOPLEGIA
• Antegrade cardioplegia is delivered through a
small cannula in the aortic root or via
handheld cannulas directly into the coronary
ostia when the aortic valve is exposed
• Retrogradecardioplegia is delivered through a
cuffed catheter insertedblindly into the
coronary sinus

60. Temperature
• Deliberate hypothermia is a reliable method
of neuroprotection and is often used during
routine CPB.
• Temp can be estimated from tympanic,
nasopharyngeal, esophageal, rectal, bladder,
skin surface, pulmonary arterial, or jugular
venous bulb temperature

61. HEATER COOLER UNIT
• The heater cooler unit
commonly known as
Haemotherm (or)
Temperature control unit
• Used to warm or cool
and to maintain the
temperature during CPB

62. SUCTIONS
Blood accumalating in the surgical
field is collected in the reservoir in
CPB Machine and returned to the
body.

63. Complications of Cardio- Pulmonary
Bypass
–Duration of bypass
–Age
–Cardiac function

64. End Organs That Can Be Adversely
Affected by CPB
• Heart
• Brain
• Kidneys
• Gastrointestinal tract
• Endocrine system