Cardiopulmonary Bypass Machine: A Comprehensive Guide for Medical Students and Professionals Overview: The Cardiopulmonary Bypass (CPB) Machine, commonly referred to as the Heart-Lung Machine, is a life-saving device used in cardiac surgeries. It temporarily replaces the functions of the heart and lungs, ensuring continuous circulation and oxygenation of the blood while the heart is stopped. This allows surgeons to perform delicate and complex procedures like open-heart surgery, valve replacement, and coronary artery bypass grafting (CABG) with precision and safety. Key Topics Covered in This Presentation: >History of CPB >Components of CPB >Working Mechanism >Indications for CPB >Monitoring During CPB >Complications & Risks >Cardioplegia Solution >Initiation & Weaning Process >Comparison Between CPB & ECMO >Understanding the Cardiopulmonary Bypass Machine: How CPB Works Venous Drainage Oxygenation & CO₂ Removal Temperature Control Pump Circulation Arterial Return Cardioplegia Administration >Why CPB Is Important in Cardiac Surgery >Potential Complications & Risks of CPB >Comparison: CPB vs. ECMO (Extracorporeal Membrane Oxygenation) Final Thoughts The Cardiopulmonary Bypass Machine is one of the most significant innovations in modern cardiovascular medicine. By allowing open-heart surgeries to be performed safely, it has saved millions of lives and continues to evolve with advanced perfusion technologies. This detailed presentation is designed for: 📌 Medical students learning about cardiac surgery techniques. 📌 Surgical technologists & perfusionists working with heart-lung machines. 📌 Cardiologists & anesthesiologists seeking a refresher on CPB principles. 📌 Researchers & healthcare professionals exploring advancements in extracorporeal circulation. 💾 Download now to gain valuable insights into one of the most essential technologies in cardiac surgery! By H. Hoda (BSc. OT Technologist)

1. Cardio Pulmonary
Bypass
H.Hoda (BSc. OT Technologist)
M a c h i n e

2. Overview
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History
Intoduction
Components
Mechanism
Indications
Monitoring
Complications
Process of Initiating
Process of Wearing Off
Cardioplegia Solution
ECMO
12
Circuit

3. Experiments in the Revival of Organisms
History
Sergei Brukhonenko, a Soviet scientist, created
the autojektor, an early version of a heart-lung
machine, which he used in experiments on
severed dog heads in the 1920s–30s. While his
work was crude, it was among the first
demonstrations of artificial circulation.
The primary inventor of the heart-lung
machine was Dr. John Gibbon, an American
surgeon. He successfully developed the machine
and performed the first successful open-heart
surgery using it in 1953.
Dr. John Gibbon

4. Introduction
It's a technique used in cardiac surgery to divert
blood away from the heart and lungs
temporarily, allowing surgeons to operate on the
heart while keeping the patient's circulation and
oxygenation maintained through a heart-lung
machine.
This procedure is crucial for performing
complex surgeries on the heart, such as coronary
artery bypass grafting (CABG) or valve
replacements.

5. Circuit

6. Components
Venous & Arterials Cannulas
Reservoir
Oxygenation
Heat Exchanger
Main Pumps
Arterial Filter
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07 Heparin Pump

7. Mechanism
01 Venous Reservoir: The blood is drained from the right
atrium or superior & inferior vena cava and also from
the left ventricle via venous cannulas.

8. Mechanism
02 Oxygenator: Oxygenator acts as a artificial lung, the
blood from the reservoir enters to the oxygenator
through the gas-permeable (silicone) membrane,
oxygen and anesthestic agent get diffuse into the blood.

9. Heat Exchanger: The heat exchanger uses water from the
heater-cooler unit (HCU) to regulate blood temperature.
Cold or warm water flows through a membrane, adjusting
blood temperature.
Mechanism
03

10. Mechanism
Pump: CPB typically has two types pumps:
Roller Pump: It consists of a rotating head with
rollers that compress a flexible tubing, pushing
blood forward in a pulsatile manner.
Centrifugal pump: It uses a spinning impeller to
create a pressure gradient, moving blood forward in
a continuous, non-pulsatile manner.
04

11. Main Pumps: CPB typically has four main pumps:
Arterial pump: Pumps oxygrnated blood from the
oxygrnator back into the patient's systemic
circulation.
Veneous drainage pump: Drains deoxygenated
blood form the body into the reservoir.
Cardioplagia pump: Delivers cold cardioplagia
solution into the coronary arteries to induce and
maintain cardiac arrest during surgery.
Cardiotomy suction pump: Collects and returns shed
blood from the surgical field to the venous reservoir.
Mechanism
01

12. Mechanism
Arterial Filter: It is a placed in the arterial line before
the blood re-enters the patient's circulation to remove
air embolism, particulate debris, preventing
complications like stroke and organ damage.
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13. Indicatons
Coronary artery bypass graft (CABG)
Valve repair & replacement
Congenital heart defect repairs
Arotic aneurysm
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The CPB is used in cardiac surgeries that require a still
and bloodless heart such as:
05 Open heart Surgeries

14. Monitoring
Arterial blood pressure
Oxygen saturation
PaCo2
Hemoglobin & Hematocrit levels
Electrolytes & Acid-Base balance
Temperature regulation
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07 Anticoagulation (Activated clotting time )

15. Complications
Systemic Inflammatory Response Syndrome (SIRS)
Hemolysis
Coagulopathy
Hypothermia related problems
Neurological complications (stroke, cognitive impairment)
Air embolism
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07 Kidney dysfunction

16. Process of Initiating
01 Preoperative Preparation:
Check & Prime the CPB machine:
Perfusionist ensures the CPB machine is properly assembled and
functioning.
The CPB circuit is primed with fluids like crystalloids, colloids to
prevent embolism.
HCU is ready for temperature management.
Anesthesia & Patient monitoring:
The patient is given general anesthesia.
Invasive monitoring line, central venous line, and pulmonary
artery catheter.
A Trans-esophageal Echocardiogram (TEE) is often used to check
cannula positioning & heart function.

17. Heparin is administered to prevent clotting in the CPB circuit.
Activated Clotting Time (ACT) is checked.
02 Check Opening and Cannulation:
Sternotomy:
A median sternotomy is performed, sternum is divided, and a rib
speader is used to open the chest.
The pericardium is open and sutured to the chest wall to keep it
open.
Process of Initiating
Heparinisation:

18. Process of Initiating
Cannulation:
The surgeon places two major cannulas:
Venous cannula (a single right atrial cannula or bicaval cannulation) is
used to drains deoxygenated blood from the body to the reservoir by
gravity or vacuum-assisted drainage .

19. Process of Initiating
Cannulation:
Arterial cannula is placed in the ascending aorta to deliver oxygrnated
blood from CPB to the body.

20. Process of Initiating
03 Initiating CPB:
Venous drainage
Blood oxygrnator & filtration
Temperature control
Pump circulation
Cardioplagia administration
# Once the heart is arrested and CPB is running, the surgeon proceeds with the
cardiac procedure.

21. Process of Wearing Off
01 Reversing Cardioplegia & Restarting the Heart:
Warming the patient:
The heat exchanger gradually warms the blood to restore normal
body temp. and rapid warming is avoided to prevent gas
embolism.
Once the surgery is complete, the patient must be carefully removed from the
CPB machine.
Flushing Out Cardioplegia:
Warm blood is perfused through the heart to wash out
cardioplegia solution and allow the heart to regain function.
Restarting the heart:
The surgeon may use pacing wires, electrical defibrillation, or
medications (epinephrine, dopamine) to restart and stabilize the heart.

22. Process of Wearing Off
02 Gradual wearing from CPB:
Gradually reduce CPB flow:
The surgeon clamps the venous line to return blood flow to the
patient’s heart.
Monitor Hemodynamics:
BP, Cardiac output, and heart rhythm are closely monitored.
Assess Lung Function & Resume Ventilation:
The anesthesia team restarts mechanical ventilation as lung
function is restored.
Vasoactive drugs (dopamine, non-epinephrine) may be given if
needed

23. Process of Wearing Off
03 Decannulation & Reversing Heparin:
Remove venous & arterial cannulas:
The surgeon removes venous & arterial cannula, ensuring no air
bubbles or clot enter circulation.
Protamine Administration(Reversing heparin):
Protamine sulfate is given to reverse heparin restoring normal
clotting.
Check for Bleeding & Close the Chest:
Hemostasis is confirmed before closing the sternum.
Chest tubes are placed to drain excess blood and fluids.
ACT is monitored to ensure clotting has normalized.

24. Cardioplegia Solution
For proper surgical access surgeon requires cardiac stand still, this is
achieved by injecting cardioplegia solution in the heart (a potassium rich
chemical solution which arrests myocardial electrical and mechanical
activity).
Composition:
Potassium
Magnesium
Calcium
Sodium
Bicarbonate or Buffer
Glucose, Glutamate, & Aspartate
Mannitol
Procaine, Lidocaine
(<140mEq/l) induces cardiac arrest by depolarizing cells.
(1.5- 15 mmol/l) stabilizes cell membranes and prevents calcium overload.
( 0.7-1.2mmol/l) helps maintain myocardial integrity.
(<140Eq/l) maintains ionic balance.
(maintains pH and prevent acidosis.)
(provides energy.)
(Act as an osmotic diuretic to reduce myocardial edema.)

25. Cardioplegia Solution
Types:
Based on temp.
Cold: (4-10C
1.
Based on composition
Crystalloid
1.
Based on delivery method
Antigrade
1.
-Reduce O2 +demand by 90%
-Provides excellent myocardial protective
-Mimic physiological conditions
-Faster recovery
2. Retrograde
-E.g. St. Thomas’ solution
-Easy to use
2. Blood
-E.g. Del Nido
-Contains oxygen, nutrients
3. Combined
-Delivered via the arotic root into coronary
arteries
-Mimics normal blood flow
2. Wram
-Delivered through coronary veins
-Use in case of arotic insufficiency or
blockage
-Used for optimal myocardial protection in
prolonged surgeries

26. Cardioplegia Solution
Complications:
Hyperkalemia
Myocardial edema
Acidosis
Inadequate myocardial protection

27. ECMO
ECMO is an advanced life support system that provides cardiac
and/or respiratory support when the heart or lungs fail to function
properly. It acts as an artificial heart-lung machine, similar to CPB,
but is used for long-term support (days to weeks) rather than short-
term surgical procedures.
(Extracorporeal Membrane Oxygenation)

28. ECMO
Types of ECMO:
Veno-Arterial ECMO (VA-ECMO) – Heart & Lung Support
Veno-Venous ECMO (VV-ECMO) – Lung Support Only
(Extracorporeal Membrane Oxygenation)
Components of ECMO:
ECMO uses components similar to a CPB machine but is designed
for prolonged use.
Centrifugal Pump – Moves blood through the ECMO circuit.
Oxygenator (Membrane Lung) – Adds oxygen and removes CO₂.
Heat Exchanger – Regulates blood temperature.
Cannulas – Tubes inserted into veins/arteries for blood flow.
Blender & Gas Line – Controls oxygen and air mixture.
Heparin Infusion – Prevents clot formation in the circuit.

29. ECMO
Indications for ECMO:
VA-ECMO (Cardiac & Respiratory Support)
(Extracorporeal Membrane Oxygenation)
VV-ECMO (Respiratory Support Only)
Cardiogenic shock (MI, myocarditis, heart failure)
Cardiac arrest (bridge to recovery or heart transplant)
Post-cardiotomy heart failure
Pulmonary embolism with RV failure
Acute Respiratory Distress Syndrome (ARDS)
COVID-19 pneumonia with respiratory failure
Lung trauma or post-lung transplant complications

30. ECMO
Why Use VV-ECMO Instead of an Artificial Ventilator?
(Extracorporeal Membrane Oxygenation)
VV-ECMO is used instead of a ventilator when the lungs are too
damaged to support gas exchange, even with high ventilator settings.
It directly oxygenates blood and removes CO₂, preventing ventilator-
induced lung injury (VILI) and allowing the lungs to heal.
Complications of ECMO:
Bleeding & Clotting Issues (due to anticoagulation)
Infections (prolonged catheterization increases risk)
Hemolysis (blood damage from the pump)
Thrombosis & Stroke (clots in the circuit)
Limb Ischemia (in VA-ECMO, due to femoral artery cannulation)

31. Feature ECMO CPB (Cardiopulmonary Bypass)
Primary Use Long-term life support (days to weeks) Short-term surgical support (hours)
Heart Function
VA-ECMO bypasses the heart, VV-ECMO does
not
CPB fully bypasses the heart
Lung Function VV-ECMO fully bypasses lungs CPB fully bypasses lungs
Cannulation Sites Large veins and/or arteries Aorta and right atrium
Pump Type Centrifugal pump Roller or centrifugal pump
Anticoagulation Continuous heparinization needed Heparin during surgery, reversed post-bypass
Mobility Can be used in ICU & transport Limited to the OR
Risk of Complications Bleeding, infection, thrombosis Clotting, bleeding, air embolism
Duration of Use Days to weeks Few hours
Key Differences: ECMO vs. CPB

32. Thank
You
H.Hoda (BSc. OT Technologist)