Hematopoietic stem cell (HSC) collection for patients with sickle cell disease (SCD) isn’t the only protocol that presents particular clinical and procedural considerations. Other challenges can range from facility-specific factors to biospecimen or research provider requirements to protocol-specific policies. In this article, we zero in on using the continuous mononuclear cell collection (CMNC) procedure to collect white blood cells (WBCs). Read on for guidelines that can help smooth this process.
Input accurate data to enhance procedure efficiency
The Spectra OptiaTM Apheresis System uses patient data and laboratory data — such as complete blood count, WBC count (including white blood cell differential), and platelet count — to set up the initial interface. Accurate data entry positions you for an efficient procedure, and the anticoagulant (AC) infusion rate and pump flow rates are based on this information.
Assess options to optimize vascular access
The optimal vascular access is the one that the patient can tolerate and that will provide an adequate inlet flow rate to process the necessary volume without multiple alarms. Some patients have adequate peripheral access, while others may require central line access. If you are targeting peripheral access, you may find it helpful to perform a vein assessment, talk with a vascular access specialized team, and
review these tips.
Evaluate inlet pump flow rate to minimize alarms
Maintaining a steady inlet pump flow rate allows for a stable interface position and optimal collection of targeted cells. This can help minimize the occurrence of pressure alarms and pump pauses, allowing the system to maintain the interface and resulting in a more efficient procedure.
Access alarms can occur during a procedure whether you are using peripheral or central line access. Excessive access alarms will extend the time of the procedure and may impact the volume that is collected. For example, an access pressure alarm can increase your procedure time by 90 to 120 seconds for each occurrence. Slowing down the inlet pump flow rate can help maintain a steady flow of blood, which may reduce access alarms.
Monitor inlet:AC ratio to mitigate clumping
Check the inlet:AC ratio to ensure optimal blood flow through the device. Remember that platelet clumping is difficult to predict since it is not dependent on a specific platelet count and will vary by patient and diagnosis.
Monitor for signs of clumping by looking at the connector through the view port and by observing the collect port image on the Collection Status or Main Run screen.
If clumping is observed or suspected,
immediately decrease the inlet:AC ratio to 8:1 until the clumping has resolved. Process at least 100 mL through the inlet pump. Then, if the clumping has resolved, consider increasing the ratio to 10:1. Continue with this ratio as you process 500 mL to 1,000 mL of inlet volume and then reassess the collection. It may be possible to increase the ratio back to 12:1, or the procedure may need to be completed at a 10:1 ratio.
Continue to reassess the connector throughout the procedure and adjust the inlet:AC ratio if needed to maintain proper anticoagulation in the connector.
