The pt Cardiopulmonary Bypass (CPB).pptx

It is about the cardiopulmonary bypass in the body of peads

1. Cardiopulmonary Bypass (CPB) 1

2. Cardiopulmonary Bypass: A Bridge to Cardiac Repair Definition: A temporary substitute for heart and lung function during cardiac surgery. It diverts blood away from the heart and lungs, allowing the surgeon to operate on a motionless, bloodless field. Historical Context: Developed in the mid-20th century. Its evolution was critical for enabling complex repairs of congenital heart defects. Purpose: Cardioplegia : To stop the heart's electrical and mechanical activity for a precise surgical environment. Hemodynamic Stability: To maintain systemic circulation and oxygenation while the heart is not beating. Temperature Management: To induce hypothermia for organ protection during the procedure. 2

3. Indications for CPB in Pediatric Patients Congenital Heart Disease (CHD): The primary indication in pediatrics. CPB is essential for the repair of complex defects like Tetralogy of Fallot , transposition of the great arteries, and hypoplastic left heart syndrome. Pediatric Heart Transplantation: CPB is used during the explantation of the native heart and implantation of the new donor heart. Repair of Great Vessel Anomalies: For procedures on the aorta or pulmonary artery. Clinical Considerations: The decision to use CPB is complex, weighing the risks of the bypass itself against the necessity of the surgical repair. 3

4. Preoperative Assessment 4

5. Patient Preparation and Pre-op Assessment Comprehensive History & Physical: Focus on the specific congenital heart defect, patient's growth and nutritional status, and any comorbidities. Diagnostic Studies: Echocardiography: Gold standard for defining cardiac anatomy and function. Cardiac Catheterization: May be required to provide detailed hemodynamic data or perform interventional procedures. Blood work: Baseline labs, including CBC, electrolytes, and coagulation studies, are essential. Anticipated Challenges: Identify potential issues like complex anatomy, pulmonary hypertension, or ventricular dysfunction that may complicate the bypass run or weaning. Clinical Pearl: A thorough preoperative assessment is the most important step in mitigating complications during and after CPB. 5

6. The Components of the CPB Circuit 6

7. Patient-Specific CPB Planning Circuit Customization: The CPB circuit is built to the specific needs of the patient, accounting for their weight, size, and surgical requirements. Fluid Management Strategy: Decide on the prime fluid composition to initiate bypass. This is often a crystalloid-based solution with colloid and blood products. Hypothermia Strategy: Determine the target temperature for the procedure. Mild hypothermia ( 32−35 ∘C ): For shorter, less complex procedures. Moderate hypothermia ( 25−32 ∘C ): For most routine pediatric cases. Deep hypothermia ( 18−25 ∘C ): For complex repairs, often with periods of circulatory arrest. 7

8. The Components of the CPB Circuit Venous Reservoir: Collects deoxygenated blood drained from the patient. Oxygenator: The core of the circuit where oxygen is added to the blood and carbon dioxide is removed. Heat Exchanger: Regulates the blood temperature for hypothermia or rewarming. Arterial Pump: Propels the oxygenated blood back to the patient. Cannulae : Specialized tubes inserted into the patient to connect them to the circuit. Clinical Pearl: The perfusionist is the expert who manages this complex circuit, continuously monitoring all parameters to ensure patient safety. 8

9. In the Operating Room 9

10. Cannulation Sites Venous Cannulation: Drains deoxygenated blood from the patient. Common sites are the right atrium, SVC, and IVC. Arterial Cannulation: Returns oxygenated blood to the patient. The most common site is the ascending aorta. Cardioplegia Cannulation: Delivers the cardioplegia solution to the heart muscle, typically via the aortic root or coronary sinus. 10

11. Initiating CPB Anticoagulation: High doses of heparin are administered to prevent clotting in the circuit. Cannulation: The surgeon places the cannulae into the chosen vessels. Initiation: The perfusionist slowly starts the pump, gradually taking over the heart and lungs' function. This is a critical transition period requiring careful monitoring of blood pressure, CVP, and oxygen saturation. Cardioplegia : Once on bypass, a cold, potassium-rich solution is delivered to stop the heart. 11

12. Management and Monitoring on Bypass Hemodynamic Management: The perfusionist manages blood flow, pressure, and temperature. Blood Gas and Electrolyte Monitoring: Frequent blood tests are performed to ensure adequate oxygenation, ventilation, and acid-base balance. Organ Protection: Strategies like hypothermia and pulsatile flow help to protect vital organs from injury. Clinical Pearl: The team continuously monitors the patient and the machine, ready to respond to any deviation from the planned course. 12

13. Weaning from CPB Rewarming: The patient is slowly rewarmed to prevent post-operative complications. De-airing: The heart is meticulously checked for any air bubbles before allowing it to start pumping. Trial of Wean: The perfusionist gradually reduces the CPB flow, allowing the heart to resume pumping on its own. Decannulation : Once the heart and lungs are functioning effectively, the patient is fully separated from the CPB circuit and the cannulae are removed. Clinical Pearl: The weaning process is a critical phase, requiring close collaboration between the surgeon, anesthesiologist, and perfusionist . 13

14. Physiological Monitoring: During weaning, continuous monitoring is critical. This includes: Hemodynamics: Close watch on blood pressure, central venous pressure, and pulmonary artery pressures. Blood Gases: Frequent blood draws to check for proper oxygenation and ventilation. ECG: To monitor for any arrhythmias as the heart resumes its own rhythm. Complications of Weaning: Hypotension: The most common complication, often requiring inotropic support. Arrhythmias: The heart may be irritable as it recovers, leading to irregular rhythms. Ventricular Dysfunction: The heart may not be strong enough to pump effectively, requiring the team to go back on bypass. 14

15. Cerebral Monitoring During CPB Importance: The brain is highly sensitive to changes in blood flow and oxygenation. Cerebral monitoring is crucial to prevent neurological injury. Near-Infrared Spectroscopy (NIRS): A non-invasive technology that measures regional cerebral oxygen saturation ( rSO2 ​). A decline in rSO2 ​ indicates reduced cerebral perfusion or oxygen delivery. It provides a real-time, continuous assessment of the brain's oxygenation. Electroencephalogram (EEG): Monitors the brain's electrical activity. Changes in EEG patterns can indicate cerebral ischemia or seizure activity. Clinical Pearl: Cerebral monitoring with NIRS is standard practice in pediatric CPB. It allows the team to adjust blood flow, pressure, and temperature to optimize cerebral perfusion. 15

16. Modified Ultrafiltration (MUF) Definition: A technique used to remove excess water and inflammatory mediators from the blood at the end of the CPB run. Procedure: The patient's blood is passed through a hemofilter , where water and small molecules are removed under pressure. It is performed after the patient is off bypass. Benefits: Hemoconcentration : Increases the hematocrit and protein concentration, improving oxygen-carrying capacity. Reduction of Edema: Decreases total body water, which can help to reduce fluid accumulation in the lungs and other tissues. Removal of Inflammatory Mediators: Helps to mitigate the systemic inflammatory response syndrome (SIRS) that is often associated with CPB. Clinical Pearl: MUF is a key strategy for improving a patient's hemodynamic stability and respiratory function in the immediate post-operative period. 16

17. THANKS 17