diffusion
movement of dissolved PARTICLES across a semipermeable membrane from the side of HIGHER concentration TO side of LOWER concentration (across
... [Show More] concentration gradient).
at equilibrium, no net transport takes place & dialysis fluid needs to be exchanged.
ultrafiltration
removes water from the blood by PUSHING it across the semipermeable membrane from the blood side within the dialyzer's hollow fibers to the dialysate side; pressure is added to the dialyzer to get the fluid out.
TMP
transmembrane pressure; pressure in dialyzer. (+ TMP can show a clot).
osmosis
movement of WATER across a semipermeable membrane from the side of LOWER solute concentration to the side with the HIGHER solute concentration, until equilibrium is reached.
osmotic pressure gradients drive ultrafiltration.
when drawing the post-BUN sample at the completion of the treatment...
1) turn off the UFR
2) decrease the dialysate flow rate to 300 ml/min or place the machine in bypass
3) reduce BFR to 50 ml/min
4) then wait 15 seconds
5) draw the BUN blood sample from arterial sample port (venous port can give falsely low readings).
the post-BUN blood sample is related to the patient's _____ reading
Kt/V
two possible causes in inaccurate Kt/V results include:
1) blood sample was drawn before correct time interval and access recirculation makes the Kt/V falsely high.
2) blood sample was drawn after correct time interval was completed, urea rebound makes the Kt/V falsely low.
optimal dialysate temperature
36.6
maximum recirculation time after a machine has been set up prior to tx cannot exceed:
2 hours
why do limit recirculation time?
limiting bacterial growth in machine
what is the procedure for blood strikethrough of an external transducer protector?
finish pt tx, remove machine from floor and take to biomed, fill out an REM.
if bleach and peracetic acid are mixed, a chemical reaction occurs, producing:
toxic gas
what are the two requirements that must be met prior to initiating water system disinfection?
1) tx floor is free of pts.
2) no other processes are using dialysis water.
what must be done to indicate the presence of disinfectant in the machines during water system disinfection?
test strips
the dialysate is a mixture of:
1) dialysis quality water,
2) acetic acid concentrate with electrolytes,
3) bicarbonate concentrate solution
electrolytes present in the acid concentrate:
sodium, calcium, magnesium, chloride, potassium, and glucose.
if dialysate conductivity is out of range, it causes:
serum electrolytes to increase or decrease to non-physiological levels & HEMOLYSIS OCCURS.
if the dialysate temperature becomes too hot:
it can hemolyze RBCs
arterial pressure (AP) must be:
NEGATIVE, because it is pulling blood from vascular access.
blending valve (water tx)
mixes hot and cold water to allow the RO system to function at the most efficient temperature (77 F, but definitely between 60-85 F).
backflow preventer (water tx)
prevents pre-treated water and disinfectants from backing up into the city water supply.
booster pump (water tx)
"boosts"
increases incoming water flow and pressure, maintains water pressure needed for components operation, and eliminates wide pressure fluctuations.
multimedia or depth filter (water tx)
filters out suspended particles like silt and sand in the water and traps solutes and other substances.
water softener (water tx)
"softens" hard water by removing calcium and magnesium from the incoming water. Works with the brine tank (salt) to prevent hard mineral deposits from accumulating and potentially damaging the RO membranes.
replaces Ca & Mg with Na.
carbon tanks (water tx)
essential for removing chlorine/chloramines from the city water.
carbon tanks are installed in pairs for a primary and backup secondary.
sample port for water testing is located right after second tank.
RO pre-filter (water tx)
removes fine carbon particles, resin beads and other debris; is placed just before the RO unit.
RO unit (water tx)
purification of water by removing bacteria, viruses, endotoxins, salt, particles, and other solutes, resulting in dialysis-quality water.
RO membranes are very permeable to water but not to chemicals are solutes; 90-99% of solutes are rejected from the water.
observations and test results listed on the Daily Water Treatment Log are entered each facility day _____ to the start of dialysis tx.
prior
who reviews the Daily Water Treatment Log for completeness and verifies that all parameters are within specified limits?
RN
total chlorine testing is done on a daily basis prior to the first pt tx and every ____ hours until all use of dialysis water is done for the day.
4
limit for chlorine/chloramine testing (aka an acceptable result):
≤0.1 mg/L(ppm)
all chlorine samples are to be drawn only after the water system has been operating for at least _____ minutes.
15
hardness testing is done on water leaving the water softener at the ______ of tx day
end
hardness testing results that are greater than _______ must be reported to biomed and FA to initiate corrective actions.
1 grain/gal [Show Less]