Fresenius Medical Care 2008K Operator's Manual page 100

Chapter 4—Monitoring the Treatment
Table 21 – The BVM Screen Features
RBV RBV
% %
100 100
90 90
80 80
100
The Relative Blood Volume (RBV) is the relation of the
current blood volume and the blood volume on the start of
dialysis expressed in %. Thus, RBV is always 100% in the
beginning. If at the end of the dialysis, RBV is e.g. 80%, the
blood volume has been reduced by 20%. There can also be
values of above 100%.
The Trend Indicator is an arrow, which roughly shows the
current direction and intensity of blood volume change. On
the display the arrow is shown to the right of the measured
value for RBV. The arrow symbols have the following
meanings:
The red blood cells (erythrocytes) are responsible for the
transport of gases in the blood (oxygen and carbon dioxide).
Hemoglobin, an iron compound giving the erythrocytes their
red color, is the active component in this process.
The hematocrit (HCT) is the packed cell volume (almost
exclusively of erythrocytes) in the blood volume.
This button allows to set a patient individual Alert Level for
RBV. The range is 70% to 100%. Entering zero deactivates
the alert function.
If RBV reaches the Alert Level, the machine will give an
audible warning and will stop ultrafiltration. Press RESET
to turn the Ultrafiltration pump back on. This alarm occurs
only once if the user does not set another Alert Level.
This graph shows the Relative Blood Volume
in red. During time periods when the BVM
can't determine RBV (e.g. saline flush) the red
line will continue dotted with the last
transferred value. The yellow dotted line
shows the alert level. The vertical dotted line
indicates the scheduled end of treatment.
: significant increase
: moderate increase
: nearly constant
: moderate decrease
: significant decrease
2008K Operator's Manual rev. K