Gambro Cobe Spectra, Справочник по основам

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Fluid Volumes
9-4 COBE
®
Spectra™ Apheresis System • Essentials Guide
Fluid Shifts
The amount of extracorporeal whole blood present in the Spectra system is
different from the amount of fluid outside the patient during the apheresis
procedure. At the beginning of the Run mode (see Figure 9-1), the system
has not drawn blood so the patient has no fluid volume deficit. As blood is
pumped into the system, saline from the channel is diverted to a waste bag.
At the end of Run divert, the patient fluid balance is decreased. In TPE and
RBCX procedures, if 100% fluid balance is selected, the patient remains at
this level throughout the procedure. In collection procedures (platelet and
WBC), fluid shifts are associated with the volume of product collected and
the amount of anticoagulant used. The Spectra system does not manage the
fluid balance during platelet and WBC procedures.
At the end of the procedure, the system returns RBCs to the patient. The
physician may choose to return only some of the RBCs in the channel to
avoid administering too much fluid. Table 9-2 shows the volume of blood
and saline the system returns at the end of each state of Rinseback mode.
Figure 9-1: Patient fluid shifts during TPE procedures
250
200
150
100
50
0
-50
-100
-150
-200
-250
Fluid Shif
t (m
L)
After Run divert
Pre-Run
Run
Pre-Rinseback
Post-Rinseback
Pre-Run: The system primes the tubing set with saline but has not drawn blood from
the patient.
After Run divert: Saline is diverted to the waste bag before blood/saline returns to the
patient.
Run and pre-Rinseback: The fluid shift does not change. This example assumes a
fluid balance of 100% for TPE and RBCX procedures. Collect and AC volumes are not
accounted for in platelet and WBC procedures.
Post-Rinseback: The fluid shift increases as saline is used to rinse the channel.