lab practical

two patients have the same inflammatory response condition

patient a hct = 30%

patient b hct = 50%

which patient is expected to have the higher esr, assuming all other factors are equal?

a. patient b

b. both equal

c. patient a

d. cannot be determined

c. patient a

during the 1-hr sedimentation period, the esr rack is placed next to a centrifuge that causes vibration

what is the most likely impact on the esr result

a. incr rouleaux formation

b. no effect

c. falsely low esr

d. falsely high esr

c. falsely low esr

which condition would be expected to have the lowest esr?

a. rheumatoid arthritis

b. multiple myeloma

c. pregnancy

d. sickle cell disease

d. sickle cell disease

an incr in fibrinogen, a decrease in albumin, and anemia are all present. what combine effect would these have on esr?

a. lower esr

b. no change in esr

c. significantly incr esr

d. unpredictable esr

c. significantly incr esr

why is esr considered a non-specific test?

a. it only detects autoimmune diseases

b. it varies by age and sex

c. it cannot be automated

d. it indicates inflammation but does not identify its cause

d. it indicates inflammation but does not identify its cause

you perform two spun hematocrit tests on the same patient and obtain 39% and 44%. what should you do according to proper procedure?

a. report the first result (39%)

b. report the second result (44%)

c. average two results and report (41.5%)

d. repeat the procedure

d. repeat the procedure

a patient’s microhematocrit reads 85%. this suggests:

a. normal hematocrit

b. polycythemia

c. severe amemia

d. hemolysis

b. polycythemia

in a capillary tube:

• x = distance from sealant / rbc interface to rbc / plasma interface

• y = distance from sealant / rbc to plasma / air interface

if x is 30mm and y is 50mm, what is the hematocrit?

a. 50%

b. 60%

c. 60% (hct = x / y x 100 = 30 / 50 × 100)

d. 30%

c. 60% (hct = x / y x 100 = 30 / 50 × 100)

a technician aligns the black vertical line at the top of the rbc slant instead of the midpoint. what is the effect?

a. falsely low hct

b. falsely high hct

c. no effect

d. only affects plasma measurement

b. falsely high hct

after centrifugation, within what time should the hematocrit be read?

a. within 10 mins

b. within 1 min after removal from rotor

c. after 5 mins

d. any time, as lomg as the tube is intact

b. within 1 min after removal from rotor

a smear is too short and thick. which mathematical adjustment would most likely improve the smear?

a. incr agnel from 30 → 45

b. incr speed by 50%

c. decr angle from 45 → 30 and slow the spread

d. decr blood drop size only

c. decr angle from 45 → 30 and slow the spread

a lavender top contains spray-dried edta (no dilution). a blue top contains 0.5mL liquid citrate added to 4.5 mL blood. what is the approximate percent dilution caused by citrate?

a. 5%

b. 10%

c. 15%

d. 20%

b. 10%

a patient’s pt and aptt are both significantly prolonged. the technologist notices that the blue top is only filled halfway. what is the most likely explanation for these results?

a. heparin contamination

b. excess plasma volume

c. excess citrate due to underfilling, falsely prolonging clotting times

d. clotting factor deficiency

c. excess citrate due to underfilling, falsely prolonging clotting times

a lab technologist accidentally collects a serum specimen instead of a blue top citrate tube and runs a pt and aptt (coagulation tests). which of the following is the most likely outcome?

a. clotting times will be accurate because calcium is added back during the assay

b. clotting times will be falsely prolonged or fail to clot because clotting factors have been consumed during clot formation

c. clotting times will be falsely shortened due to the absence of fibrinogen

d. there will be no effect on coagulation results bc serum is clear like plasma

b. clotting times will be falsely prolonged or fail to clot because clotting factors have been consumed during clot formation

a smear shows prominent rouleaux formation. which clinical condition is most commonly associated with this finding?

a. iron deficiency anemia

b. acute leukemia

c. multiple myeloma

d. hemophilia

c. multiple myeloma

the x-axis of a differential scattergram represents

a. cell size

b. hemoglobin content

c. cell granularity / internal complexity

d. cell count

c. cell granularity / internal complexity

two peaks on an rbc histogram may indicate

a. spherocytosis

b. iron deficiency anemia only

c. recent transfusion

d. platelet clumping

c. recent transfusion

at 50x oil, you average 9 wbcs per field in 10 fields. the analylzer reports 28,000uL.

i) calculate the smear estimate

ii) does this correlate within ± 30%

i) 9 × 3000 = 27,000 uL

30% of 28,000 = 8,400

acceptable range = 19,600 - 36,400
ii) yes

total wbc = 7.2 K / uL

differential:

• neutrophils 58%

• lymphocytes 30%

• monocytes 10%

• eosinophils 2%

calculate the absolute monocyte count

7.2 × 0.10 = 0.72 K / uL

a patient has the following cbc results:

• hemoglobin 9.2 g/dL (low)

• hematocrit 30% (low)

• mcv 72 fL (low)

• mch 22 pg (low)

• mchc 29 g/dL

based on these findings, what would you expect to see on the peripheral blood smear when assessing rbc morphology?

a. normocytic, normochromic rbcs

b. macrocytic rbcs with hyperchromia

c. spherocytes with incr mchc

d. microcytic, hypochromic rbcs

d. microcytic, hypochromic rbcs