Gambro Cobe Spectra, Справочник по основам

Страница: 107 / 245

Anticoagulation
COBE
®
Spectra™ Apheresis System • Essentials Guide 8-5
Gambro BCT has not validated ratios higher than 15:1. Higher ratios
may cause interface instability and platelet aggregates to form in the
extracorporeal circuit and/or collection bag, and may affect cellular
viability. The amount of AC stored with the product (during platelet or
WBC procedures) influences the storage environment of the collected
cells. Using inadequate amounts of anticoagulant may result in the
formation of microaggregates or clots in the product.
You should configure an inlet:AC ratio which
•
Prevents the blood from clotting during separation and collection.
•
Establishes a pH and ionized calcium environment that helps
prevent platelets from clumping.
•
Establishes the initial pH necessary for appropriate storage of
platelets or cellular components.
Platelet Collection Procedures
You may configure a custom inlet:AC ratio (in which you specify a
different inlet:AC ratio for different portions of the procedure) or choose
an automatic ratio. If you chose one of the three automatic ratios (low,
medium, or high), the system uses the donor Hct to calculate the
inlet:AC ratio. The inlet:AC ratio varies with the donor Hct because the
pH buffering capabilities of the blood in an extracorporeal circuit is
directly related to the donor Hct.
The system calculates the inlet pump flow rate based on the the AC
pump flow rate and inlet:AC ratio.
Example:
AC Pump Rate X Inlet:AC Ratio = Inlet Pump Flow Rate
5 mL/min X 9:1 = 45 mL/min
When concurrently collecting plasma and platelets, you process more
blood, increasing the platelet yield by 5% to 20%.
Increasing the inlet pump flow rate does not result in an equivalent
increase of ACD-A to the donor because some of the ACD-A flows to
the plasma collection bag. The Spectra system automatically increases
the inlet pump flow rate based on the donor data and the amount of
ACD-A removed to the plasma collection bag.
Managing Symptomatic Hypocalcemia
ACD-A can cause symptomatic hypocalcemia in certain patients or
donors. Mild forms of this condition are generally recognized by
peripheral paresthesia, tingling sensations in the extremities, and/or
restlessness. Severe forms of this condition can result in significant
cardiac dysfunction. Gambro BCT recommends that the condition of
the donor or patient be assessed frequently throughout the apheresis
procedure.
If symptomatic hypocalcemia occurs, pause the Spectra system and
notify the physician. To continue the Run mode, decrease the inlet
pump flow rate. The inlet:AC ratio remains the same, but the AC pump
flow rate decreases. This effectively lowers the rate of anticoagulant
infusion to the donor/patient and should alleviate the symptoms. If it
does not alleviate the symptoms, stop the procedure and administer
appropriate medical treatment.
Caution: Patients or donors with impaired or abnormal citrate
and/or calcium metabolism (e.g., liver and renal diseases) can
present an increased risk of citrate sensitivity. The attending
physician should assess the appropriateness of such patients or
donors for apheresis and prescribe how they should be monitored
during the apheresis procedure.