microscopic of the urine Flashcards
purpose is to detect and to identify insoluble materials present in the urine.
microscopic examination
contribute formed elements to the urine.
blood, kidney, lower genitourinary tract, and external contamination
To enhance the cost-effectiveness of urinalysis, many laboratories have developed protocols whereby microscopic examination of the urine sediment is performed only on specimens meeting specified criteria.
Macroscopic Screening
Specimens should be examined while?
fresh or adequately pre-
served
Formed elements—primarily RBCs, WBCs, and hyaline casts—disintegrate rapidly, particularly in
dilute alkaline urine
may cause precipitation of amorphous
urates and phosphates and other non-pathologic crystals that can obscure other elements in the urine sediment
refrigeration
Warming the specimen to __ prior to centrifuging may dissolve some
of these crystals.
37°C
minimizes external contamination of the sediment
midstream clean-catch specimen
prior to decanting a portion into a centrifuge tube.
thoroughly mix the specimen
standard amount of urine, usually between _____ is centrifuged in a ___ tube.
10 and 15 mL, conical
frequently used because multiparameter reagent strips are easily immersed in this volume, and capped centrifuge tubes are often calibrated to this volume.
12-mL volume
If obtaining a ___ , as with pediatric patients, the volume of the specimen used should be noted on the report form.
12-mL specimen is not possible
speed of the centrifuge and the length of time the specimen is centrifuged should be
consistent
produces an optimum amount of sediment with the least chance of damaging the elements.
centrifugation for 5 minutes at a RCF of 400
should be routinely performed
centrifugation calibration
to slow the centrifuge causes disruption of the sediment prior to decantation and should not be used.
braking mechanism
To prevent biohazardous aerosols, all specimens must be
centrifuged in ___
capped tubes
