2S [LAB]: HCT Flashcards
Hematocrit is also known as ___
Packed cell volume (PCV) or Erythrocyte volume fraction (EVF)
Hematocrit method commonly used in the laboratory
Adam’s microhematocrit method
Coagulant of choice in HCT determination
Heparin/ EDTA
Color of the ring of capillary tube that is heparinized
Red
Color of the ring of capillary tube that is non-heparinized
Blue
How much of the capillary tube should be filled in HCT determination?
2/3 or 3/4
Which end of the capillary tube is sealed using sealing clay?
Colored ring eng
The sealing clay should be at least how many mm thick?
4 mm
Centrifuge conditions used in HCT determination
10 000 g - 15 000 g for 4-5 mins
In HCT determination, the duplicate should agree within how many percent?
1%
Uses precalibrated capillary tubes and has built-in hematocrit scales, which eliminates the need for separate reading devices
READACRIT centrifuge
Reference range of HCT in males
40-54%
Reference range of HCT in females
35-49%
Identify the effect of the following on HCT reading:
Improper sealing of the capillary tube
Decreased
Identify the effect of the following on HCT reading:
Short draw
Decreased
Identify the effect of the following on HCT reading:
Specimen was not mixed properly
Decreased or increased
Identify the effect of the following on HCT reading:
Insufficient centrifugation
Increased
Identify the effect of the following on HCT reading:
Delay in reading results
Increased
Identify the effect of the following on HCT reading:
Buffy coat of the specimen was included in the reading
Increased
Identify the effect of the following on HCT reading:
Microhematocrit reader is not used properly
Increased or decreased
Identify the effect of the following on HCT reading:
Trapped plasma
Increased by 1-3%
In automation, how is HCT computed?
RBC x MCV
Amount of plasma that still remains in the RBC portion after the microhematocrit has been spun
Trapped plasma
Identify the effect of the following on HCT reading:
Blood loss
Temporarily low
Identify the effect of the following on HCT reading:
Fluid loss associated with dehydration
False increase
Identify the effect of the following on HCT reading:
Improper flushing of an IV catheter
Decreased
Which calibration of Wintrobe tube is used for HCT determination?
10-0
Centrifuge conditions in HCT determination using Wintrobe tube
3000 rpm for 30 mins
Anticoagulant used in Haden’s modification
1.1% sodum oxalate
Centrifuge conditions in HCT determination using Haden’s modification
3000 rpm for 20 mins
When using the Haden’s modification and the blood is at least 5mL, the shortcut factor is ___
20
An HCT determination method that uses a tube with bulb and calibration of 1-10cm
Van Allen method
Anticoagulant used in Van Allen method of HCT determination
1.6% sodium oxalate
Centrifuge conditions in HCT determination using Van Allen method
2500 rpm for 15-30 mins
Anticoagulant used in Sanford-Magath method of HCT determination
1.3% sodium oxalate
In HCT determination, this method uses a tube that is about 5 inches long and a funnel-like mouth
Sanford-Magath
Anticoagulant of choice used in Bray’s method of HCT determination
Heparin
An HCT determination method that uses a tube similar to Wintrobe tube
Bray’s method
An HCT determination that is stand at a vertical position for 1 hour
Bray’s method
