Hematocrit & Erythrocyte Sedimentation rate

Test 2

what does ESR test measure

the rate at which RBCs settle out of diluted human plasma over a certain period of time

what units of measurement are used to report ESR

mm/Hr

When should an ESR be set up following collection

within 3 hours

how long should the ESR tube sit before reading (Westergren manual method)

60 minutes

what is formed in the ESR column that help with the settling of RBCs

Rouleaux

what term indicates a high fibrinogen level in the blood

hyperfibrinogenemia

what term indicates a high immunoglobulin level in the blood

hyperimmunoglobulinemia

why can you not subtract and get the difference in an ESR reading

because RBCs dont fall at a constant rate, they fall faster at the beginning and slow down over time

sample type for ESR test

freshly collected in EDTA via venipuncture

safety rule when plunging the ESR tube into the reservoir

use both hands to control the blood flow up the tube

patients with elevated ESR levels

temporal arthritis, rheumatoid arthritis, chronic infections, some anemias, pregnancy

example of rouleaux forming conditions

multiple myeloma

diseases with abnormal red cell morphology that are associated with decreased ESR levels

iron deficiency anemia, sickle cell anemia, spherocytes

is ESR a specific or nonspecific test

non-specific

what is used to diagnose temporal arthritis

ESR

what method is used to measure ESR

Westergren/Winterobe ESR method

if doing an automated ESR method, what colour tube is used

black stopper

what additive is in black topped tubes

Na citrate anticoagulant

how is blood stored

blood can be kept at RT for up to 24 hours (can be refrigerated but warmed up before use)

commercial kit that measures ESR

MiniCube by Diesse

what tube is used in thte MiniCube and how many samples at once

uses EDTA tubes, 4 samples at one time

what is a better, more sensitive alternative to ESR

C-Reactive Protein (CRP)

why is it better to use CRP than ESR

because it is a more sensitive and accurate reflection of inflammation

what does CRP measure

it measures the level of the C reactive protein in the blood to help detect inflammation and monitor conditions that cause it

what does agglutination in the latex agglutination test indicate

visible agglutination indicates the presence of CRP in serum

what are the downsides to latex agglutination test

the test does not specify the cause or location of the inflammation

how does the latex agglutination test work

latex particles are coated with CRP specific antibodies, when latex particles are mixed with serum containing CRP, an agglutination reaction happens

half life of CRP

stable half life of 19 hours

what kind of inflammation is ESR most useful for

chronic inflammation and general indication of inflammatory status

what kind of inflammation is CRP most useful for

detection and monitoring of acute inflammation

in the first 24 hours of disease progress, the ESR may be ____ and the CRP may be ____

ESR is normal while CRP is elevated

what produces CRP

the liver (in response to inflammation)

define hematocrit

the volume of packed red blood cells that occupies a specific volume of whole blood

what is another name for hematocrit

packed cell volume (PCV)

what are the units of measurement for hematocrit

L/L

what end of the capillary tube faces towards the outside of the centrifuge for manual hematocrits

the clay end points towards the outside

what is HCT a good indicator for

RBC volume (oxygen carrying capacity)

Low HCT

anemia

high HCT

polycythemia or dehydration

what quality control is in place to ensure you are reporting an accurate manual HCT

running tubes in duplicate

what is the calculation for HCT

(RBC) x (MCV/1000) = HCT (in L/L)

what is the rule of 3

Hematocrit value should be 3 times the value of hemoglobin

what should you do if the rule of 3 does not agree

rerun, if the same then report

when does the rule of 3 apply

only to specimens that have normocytic and normochromic RBCs

how to find HGB if you have a HCT value

divide HCT by 3

how to find HCT if you have a HGB value

multiply HGB by 3

what is reported as a number in the hundreds (or high tens)

HGB

what is reported as a decimal number (to 3 decimals)

HCT

the HCT is 0.450 L/L, what is the HGB

HGB = 150 g/L

if an EDTA tube was used for an ABO, then an HCT was added on, how would the HCT result be

falsely increased (because some plasma was removed in ABO, causing more concentrated red cells)

percent certainty in manual HCT

1-2%

what does the buffy coat contain, and is it included in a hematocrit determination

the buffy coat contains WBCs and PLTs and is excluded in the hematocrit determination