HEMOGLOBINOMETRY Flashcards
most common anticoagulant for routine hematology testing
ethyldiaminetetraacitic acid (edta)
what tests has minimal effects on blood cell morphology
complete blood count
differential count
how long does CBC testing should be stored if it is stored at RT and if it is stored at 4’C
6hrs - RT
24hrs - 4’C
why peripheral blood films should be prepared within 3hrs?
reduce cell detoriation and morphology artifacts
may be necessary to use manual methods when counts exceed the linearity of an instrument
manual cell count
equipment used in manual cell count
hemacytometer
purpose of platelet count
to count the platelets in a 1 liter of blood
lyses the nonnucleated rbcs in the specimen to prevent interference in the count
diluting fluid
purpose of wbc count
to count the wbc’s in a 1 liter of blood
diluting fluid used in wbc count
1% buffered ammonium oxalate
ratio of platelet to diluting fluid
1:100
they are small and can be confused easily with dirt or debris
platelet
ratio of wbc to diluting fluid
1:20
diluting fluid used in platelet count
1% ammonium oxalate
the adherence of platelets found around neutrophils, producing a ring or satellite effect. what anticoagulant is used in this phenomenon.
platelet satellitosis; edta
what anticoagulant should correct the platelet satellitosis
sodium citrate
more accurate manual rbc procedures
hematocrit
hemoglobin concentration
rarely performed because of the innacuracy of the count and questionable necessity
red blood cell count
commercially available for wbc and platelet counts
capillary pipette
diluent reservoir systems
carry oxygen to and carbon dioxide to the tissues
hemoglobin
it consists of a capillary pipette that fits into a plastic reservoir containing 1.98% ml of 1% buffered ammonium oxalate
Leuko Chek
what is the absorbance of cyanmethemoglobin and is it direct or indirectly proportional to the hemoglobin concentration
540nm; directly proportional
this reagent is sensitive to light and it should be stored in a brown bottle
cyanmethemoglobin reagent
what ingredient of the hemoglobin reagent is highly toxic and must be used cautiously
cyanide
volume of packed rbcs that occupies a given volume of whole blood
hematocrit
this instrument uses precalibrated capillary tubes and has built-in hematocrit scales, which eliminates the need for separate reading devices
READACRIT centrifuge
This rule applies only to specimens that have normcytic normochromic rbcs
rule of three
what are the redd blood cell indices
mean cell volume
mean cell hemoglobin
mean cell hemoglobin concentration
eliminates the use of sealants
SUREPREP capillary tubes
average volume of rbcs expressed in femtoliters
mean cell volume
average weight of hemoglobin in a RBC, expressed in picograms
mean cell hemoglobin
average concentration in each individual rbc. the units used are grams per deciliter
mean cell hemoglobin concentration
last immature rbc stage
reticulocyte
precipitated hemoglobin, usually appear round or oval, and tend to adhere to the cell membrane
heinz bodies
round nuclear fragments and usually singular
howell-jolly bodies
iron in the mitochondria whose presence can be confirmed with an iron stain, such as prussian blue
pappenheimer bodies
reticulocytes that are released from the marrow prematurely
shift reticulocytes
useful in detecting early hematopoietic activity after chemotheraphy or hematopoietic stem cell transplantation
Immature Reticulocyte Fraction (IRF)
useful to detect early iron deficiency
reticulocyte hemoglobin
tests to detect and monitor the course of inflammatory conditions such as rheumatid arthritis, infections,or certain malignancies
erythrocyte sedimentation rate
not a specific test for inflammatory diseases and is elevated in many other conditions also it is not recommended as a screening test to detect inflammatory conditions in asymptomatic individuals
erythrocyte sedimentation rate
most commonly used method today that the taller column height allows the detection of highly elevated esrs
modified westergren erythrocyte sedimentation rate
offers the ability to produce rapid and accurate results that facilitate faster treatment, which can decrease hospital length of stay
point -of-care testing
this method uses oxalate-anticoagulated whole blood
wintrobe erythrocyte sedimentation rate
means that regardless of where the diagnostic testing is performed or who performs the test, all testing sites must follow the same regulatory requirements based on the complexity of the test
testing site neutrality
useful in selecting equipment that best covers the patient population for the institution
patient correlation studies
use the conductivity method to determine the hematocrit
i-STAT 1 and Epoc
instrument that eliminates the interference from turbidity in the specimen and what is its waveleghths
HemoCue hemoglobinometer; 570nm and 880nm
used to detect indirectly evaluate the oxygen carrying capacity of the blood
hemoglobin estimation
physiological factors in hemoglobin estimation
age
gender
pregnancy
physical activity or exercise
pathological factors in hemoglobin estimation
testosterone deficiency
renal deficiency
myelodysplasia
diminished erythrocyte
bone marrow suppresion
blood loss
most accurate method for estimation of hb
cyanmethemoglobin method
specimens used in cyanmethemoglobin method
edta anticoagulated blood
capillary blood
this method is based on the capacity of hemoglobin to combine with the same maximum volume of carbon dioxide as of oxygen
gasometric method
this method or technique of measuring hemoglobin is not routinely performed except as a method of screening blood donors
gravimetric method
hydrochloric acid and hemoglobin produces what and what is its color
acid hematin; brown hematin
