PROTOCOL TO REPLACE AN OXYGENATOR WITHOUT INTERRUPTING CPB.

Michael A. Hart C.C.P.

1. Open and inspect new oxygenator.

2. Attach the ends of a two foot length of 3/8” tubing to the blood inlet and outlet ports of the new oxygenator.

3. About two inches from the blood inlet of the oxygenator, aseptically cut the tubing and insert a 3/8”x 3/8” straight connector with a leur port. Make the connection closest to the oxygenator as tight as possible. The connection to the long part of the tubing should only be over the first ridge on the connector since it will be removed later during the change-out. Attach a stopcock to the luer port on the connector.

4. Repeat the process about two inches from the blood outlet.

5. Band both connections on the inlet and outlet of the oxygenator and both connections on the oxygenator side of the 3/8” connectors.

6. Place a clamp in the middle of the long section of tubing, and then hang the oxygenator from the pump mast.

7. Do not remove the gas inlet cap. Attach a CO2 flush line to the lower of the two stopcocks and open the higher one to vent. Turn on the CO2 to four or five L/M. Flush for about one minute then disconnect and close the stopcocks.

8. About four inches from the unbanded connection, cut the tubing and plug the four inch piece with a 5ml syringe plunger to seal it. Repeat the process at the other unbanded connection.

9. At this time additional volume may be added to the circuit to compensate for the static priming volume of the new lung.

10. Rearrange any brackets that will be in the way when you are handling the old lung and cutting the bypass line. Be careful not to kink any lines.

11. Clamp the shunt line around the bad oxygenator with three additional clamps. When this is done you should have two clamps about 1 inch apart then an 8 inch section of tubing to bend in half and cut later, then two more clamps about 1 inch apart. It should look like this: ------/-/--------/-/------ (If you squeeze the center section and collapse the tubing with your hand while applying the last two clamps, when you release your grip, there will be negative pressure in this section and it will squirt less when cut.)

12. place the new oxygenator close to the old one with the ports in the same orientation.

13. Divide the eight inch section of tubing between the two sets of clamps.

14. Remove the short piece of tubing with the syringe plunger in it from the 3/8” connector and attach one half of the divided shunt line to the connector. Repeat with the other end.

15. Turn the new oxygenator so that the inlet is at the bottom and the outlet is on top. Connect a purge line to the stopcock on the 3/8” connector at the outlet and attach the other end to the cardiotomy reservoir.

16. Remove the two clamps on the inlet side of the shunt line connected to the new oxygenator.

17. Open the stopcock/purge line and the new lung will slowly prime. Your MAP will sag a bit since some of your flow is diverted to the new oxygenator. Just increase the RPM’s until the pressure is normalized.

18. After the new lung is primed, manipulate the short section of tubing on the outlet, distal to the connector to send any trapped air out the purge line.

19. Remove the first clamp on the outlet side and look for any air bubbles that may have been trapped under the clamp.

20. Attach the O2 line to the new lung and remove the vent cap. Ventilate it for about sixty seconds to blow off the excess CO2 while recirculating through the purge line.

21. Slowly remove the last clamp. Now you have flow through both oxygenators and the purge line. Turn off the purge line and clamp the inlet and outlet of the old oxygenator. Adjust flow.

22. Switch water lines from the old, to the new lung. Band all new connections.

23. Take a deep breath, wait two minutes and draw a blood gas to document that the new oxygenator is functioning.

The exchange is now complete. All blood flow is now through the new oxygenator to the patient. At no time during this exchange was patient blood flow interrupted. The only blood loss was the volume in the eight inches of shunt tubing that was cut, about 20ml. The volume in the old oxygenator is recoverable at the end of the case when the circuit is drained.

Michael A. Hart C.C.P.