Clumping in any exchange procedure can lead to many issues if not addressed. If it occurs in the connector of an exchange set, clumping is fairly simple to identify because you see a change in the interface, where plasma and red cells meet during an exchange.
The interface inside the connector should appear like the edge of a knife, with layers clearly separated. If, instead, you see an unstable interface — sometimes described as “ocean waves in the connector” — that is the most common indication of clumping.
Clumping in the inlet line trap, on the other hand, is difficult to see and may not even be visible. Instead, it may be indicated by inlet alarms, the need for repeated inlet flushing, or the appearance of “stringy stuff” in the inlet line or port.
If there is no fluid visible in the line beyond the inlet line trap, then the inlet line trap is occluded.
- Total occlusion of the inlet line trap may result in an “Inlet Pressure Sensor Malfunctioned” alarm (version 12 alarm #3017). One possible cause of total occlusion is an obstructed inlet line trap. If this alarm occurs more than once, you should discontinue the procedure.
- Partial occlusions are a challenge to assess because it is difficult to see clumping in the inlet line trap. (Keep reading for helpful tips to keep in mind when assessing possible clumping in the inlet line trap, even when you cannot see it.)
If you are concerned about possible clumping in the inlet line trap, these points can help you assess the situation:
- Multiple inlet alarms that result in pumps pausing. If pumps are paused, the Spectra Optia screen instructs you to open the inlet saline roller clamp for a saline drip. This prevents stagnant blood — whole blood that is not yet anticoagulated and sits in the inlet line between the manifold and the patient connection, where it can begin to clump. If this happens and the procedure resumes, the clump will move up the inlet line and get caught in the inlet line trap. In this situation, consider decreasing the inlet:AC ratio to 8:1 while troubleshooting the issues with the inlet line access.
- Multiple low-pressure alarms or repeated flushing. If the inlet access works well at the beginning of the procedure, but then has multiple inlet pressure low alarms or needs to be flushed repeatedly to clear the alarm, clots may be present in the inlet line trap or sensor.
- “Stringy stuff” in the inlet line or port when it is flushed. If this material is visible in the inlet line or port, it is most likely also in the inlet line trap and/or the inlet line sensor. This clot may be difficult to clear, and you may need to discontinue the procedure.
When assessing potential clumping issues, remember the exchange procedure flow path. If there is no fluid visible in the line after the inlet line trap, then the inlet line trap is likely occluded. Keep these points in mind:
- You can try decreasing the inlet:AC ratio to 8:1. But once the inlet line trap is occluded, it may be too late to correct the problem, and you may need to discontinue the procedure.
- If there is no fluid in the line after the inlet line trap, then no fluid is being pumped into the centrifuge. That will create additional alarms — for example, low-level reservoir alarms or centrifuge pressure exceeds limit alarms.
- If no fluid is reaching the centrifuge, it can also cause negative pressure in the channel, preventing red blood cells (RBC) from leaving the channel. This may cause a high interface and alarms from the automated interface management (AIM) system indicating that RBC are seen near the top of the channel.
- Clumping may also be a challenge with red blood cell exchange (RBCX) for sickle cell disease (SCD) patients. SCD patient blood can be very viscous and have high platelet counts. It is most important to assess for clumping when performing RBCX procedures on SCD patients to avoid negative pressure in the centrifuge. If your facility’s standard operating procedures allow, consider starting the inlet:AC ratio lower at the beginning of the procedure.
If you have questions or want to learn more, please email us at or call 877.339.4228.
Sources:
Terumo Blood and Cell Technologies. Concepts of Anticoagulant Management. Training Presentation. 2022. Part number TS-OPTI-01105.
Terumo Blood and Cell Technologies. Red Blood Cell Exchange (V12 RBCX) Rx Only Procedure Training (Including Single-Needle Option). 2023. Part number TS-OPTI-00799.
Terumo Blood and Cell Technologies. Therapeutic Plasma Exchange (TPE). Spectra Optia Apheresis System. Training Presentation. 2023. Part number TS-OPTI-01918.