ChatGPT’s Answer

1. Pre-Procedure Preparation

Team Communication & Role Assignment: Ensure all team members (surgeon, perfusionist, anesthesiologist, and nursing staff) are aware of the plan. Clarify roles and responsibilities.

Backup Equipment Check: Confirm that a replacement (backup) oxygenator is available, properly primed, and has been checked for integrity according to manufacturer and institutional guidelines.

Review Patient Status: Confirm that the patient is stable and that the indication for oxygenator exchange (e.g., clot formation, malfunction, or performance issues) is clearly understood.

Review the CPB Circuit Schematic: Understand the circuit’s configuration to plan where clamps, connectors, and lines will be managed.

2. Circuit Preparation

Stabilize CPB Flow: If possible, adjust flows and pressures to minimize turbulence and risk during the exchange. Some teams may briefly lower the flow if the situation allows while maintaining adequate tissue perfusion.

Ensure Air Removal: Confirm that both the existing circuit and the replacement oxygenator are de-aired to prevent embolism.

3. Isolating the Oxygenator

Clamp the Circuit: Using the appropriate clamps, isolate the oxygenator from the rest of the circuit. This step minimizes the risk of air entry and loss of priming fluid.

Monitor Pressures and Flows: Constantly observe circuit pressures and flows during clamping to detect any issues early.

4. Disconnecting the Faulty Oxygenator

Secure Connections: Make sure all tubing and connectors leading to the oxygenator are securely clamped and identified.

Disconnect Carefully: Remove the malfunctioning oxygenator from the circuit, taking care to avoid introducing air into the system.

5. Connecting the Replacement Oxygenator

Inspect the Replacement Device: Double-check that the new oxygenator is intact, correctly primed, and oriented properly per manufacturer guidelines.

Attach the Oxygenator: Connect the new oxygenator to the CPB circuit, ensuring that all connectors and tubing are firmly secured.

De-air the New Oxygenator: Use the recommended de-airing techniques (e.g., venting via designated ports) to ensure no air remains in the device or connecting tubing.

6. Reintegrating and Restarting the Circuit

Remove Clamps Gradually: Once the new oxygenator is securely connected and de-aired, carefully remove the clamps to allow blood flow to resume. This should be done slowly while watching for air bubbles.

Monitor Circuit Parameters: Immediately observe circuit pressures, flows, and gas exchange performance. Look for any signs of leaks, emboli, or abnormal pressures.

Functional Checks: Verify that the new oxygenator is effectively oxygenating the blood by checking oxygenator performance metrics and blood gas analyses.

7. Post-Exchange Management

Team Huddle and Documentation: Communicate with the team regarding the successful exchange. Document the procedure in detail including the indication, steps taken, and any issues encountered.

Continuous Monitoring: Keep close observation on the CPB circuit and the patient’s hemodynamics. Be prepared to troubleshoot if any problems arise with the new oxygenator.

Post-Procedure Review: Once the patient is stabilized, a review meeting should be held to evaluate the exchange process and identify any improvements for future procedures.

Important Considerations

Institutional Protocols & Training: Every institution will have specific guidelines and checklists for such procedures. Always adhere to your local protocols and training.

Manufacturer Guidelines: Refer to the oxygenator and CPB circuit manufacturer’s instructions for specific details on de-airing, clamping, and connection procedures.

Safety First: If there is any doubt or technical difficulty during the procedure, pause and reassess with your team. Patient safety is paramount.

Perfusion Mind’s Answer

The steps to change out the oxygenator during cardiopulmonary bypass (CPB) are as follows:

1. Inform the surgical team that you think it is necessary to change out the oxygenator.

2. Depending on the circumstances and how soon it will be before it is necessary to change out the oxygenator, consider cooling the patient and increasing the FiO₂ to 100% in order to decrease the patient's metabolism and increase the patient's pO₂, respectively, in preparation for the cessation of perfusion.

3. Prepare to change out the oxygenator by collecting the necessary supplies including:

• A new, primed oxygenator with 3/8" tubing connected to the new oxygenator's blood inflow and outflow and 3/8-3/8" connectors on the ends of the tubing (the tubing should be clamped to keep the new oxygenator primed);
• Tubing clamps;
• Normal saline-filled bulb syringes (or another means to create a wet-to-wet connection);
• Chlorohexidine sticks (to clean the original 3/8" tubing);
• Sterile scissors.

4. Prep the part of the lines that will be cut with chlorohexidine sticks or alcohol swabs.

5. When the surgeon has indicated that he/she is ready for you to turn off the pump, close all shunts and announce to the room that you are coming off bypass, then turn off the pump and clamp the arterial line.

6. Using two tubing clamps, clamp the old oxygenator's inflow tubing (separating the clamps by approximately 3-5 inches) and cut between the two tubing clamps.

7. Using a bulb syringe, make a wet-to-wet connection between the heart-lung machine's arterial pump's outflow and the 3/8" connector attached (by the small segment of tubing) to the new oxygenator's blood inlet.

8. Apply 1 more clamp to the (already-clamped) arterial line (approximately 3-5 inches away) and cut between the clamps.

9. Using a bulb syringe, make a wet-to-wet connection between the arterial line and the 3/8" connector which is attached to the new oxygenator's outflow.

10. Attach the oxygen line to the new oxygenator.

11. After ensuring there is no air in the system, remove all clamps and resume flow to the patient.

12. When it is safe to do so and if necessary, make connections from all of the new oxygenator's purge lines and cardioplegia line to the original reservoir and cardioplegia circuit, respectively.