Fresenius Medical Care 2008T Operator's Manual page 278

Glossary
Flow Indicator—A clear, cylindrical section of the dialyzer supply line that allows observation of the
dialysate flow. When the dialysate flow is on, a small float inside the cylinder bobs up and down in
rhythm to the dialysate pump. When the flow is off, the float sinks to the bottom of the cylinder.
Hard Limits—Unchangeable limits that are hard coded in the software and define the maximum and
minimum, alarm-window values for the arterial, venous, and transmembrane pressures, and the dialysate
temperature and conductivity. Hard limits are not apparent unless the user attempts to set a value outside
the hard limit range.
Hemolysis—Rupture of red blood cells. This may be caused by hyponatremia (low blood sodium),
dialysate that is too hot or too dilute (hypotonic), chloramines, copper, or nitrates in dialysate water,
bleach in the dialysate, low dialysate conductivity, too-high arterial pressure or kinked blood tubing.
Idle Mode—When dialysis is first entered after a long power down, if a water alarm (temperature or
conductivity) exists, the dialysate flow will be 800 ml/min until the machine is up to temperature and
conductivity. The dialysate flow then drops to 300 ml/min while the machine is "idle". The machine will
also enter Idle Mode after a treatment is finished (RTD = 0, blood not sensed, and Blood Pump stopped,
and the dialysate flow rate > 300 ml/min). This mode is terminated when treatment is started (RTD > 0 or
blood sensed by the optical detector) or the dialysate flow rate is changed manually.
Kecn—Effective Clearance as determined with conductivity measurements. The calculated clearance
based on the change in conductivity of the pre-dialyzer versus post dialyzer dialysate. Kecn appears in
OLC Data subscreen of the "Kt/V AF" screen.
Keys—Are located on the control panel, outside the display screen. Keys are used to enter numbers,
confirm selections on the display screen, and activate certain functions.
KoA—Overall mass transfer coefficient multiplied by surface area of a dialyzer.
Kt/V—A measure of therapy delivered to the patient. (K = clearance rate, t = time, V = urea distribution
volume). The Kt/V value shown are Single Pool Values (spKt/V). The OLC system is used to determine
the effective dialyzer clearance used for this determination.
KUF—An ultrafiltration coefficient that describes how permeable a dialyzer is to water. It is a direct
function of surface area and is defined as the number of millimeters of fluid per hour that are transferred
across the membrane per mmHg TMP.
Long Power Down—The act of turning off the machine for longer than two minutes. Certain
information stored in memory is lost after two minutes, and some treatment parameters are reset to their
default settings. Power failures are not the same as long power downs, and treatment data are saved when
power to the machine is interrupted in such instances. (See short Power Down and Power Failure
recovery)
Numeric KoA—See KoA.
OLC (Online Clearance)—This is an optional system that can determine the effective conductive
clearance of a dialyzer up to six times during dialysis.
Override—All protective systems are in operation during treatment. During a blood leak alarm, the user
has the option to temporarily suspend (override) a protective system by pressing and holding the RESET
key for three seconds. During a blood leak override, the machine's blood leak monitor is inactive for
three minutes. The Status Box will indicate a blood leak override is in effect.
Peracetic acid—A disinfectant used in the Chemical/Rinse program to disinfect the hydraulic system.
278 2008T Machine Operator's Manual P/N 490122 Rev N