HEME Lab exam 1

What test is good for Hematology tubes and cell counts?

What test is good for Hematology tubes and cell counts?

EDTA

What are the benefits of lithium heparin tubes (chemistry testing?

• preserves RBC integrity best

• best suited for tests where prevention of RBC lysis is important

What are the cons of lithium heparin tubes?

• harsh on cell morphology

What tube is good for coagulation testing?

• sodium citrate because Factors V and VIII are happy

Order of draw

• sodium citrate tubes

• serum tubes

• lithium heparin tubes

• EDTA tubes

• Fluoride (glucose) tube

What causes Hemolysis?

• vigorous mixing

• bore of needle and forcing blood through

• remnant of alcohol

• prologued use of tourniquet (causes hemolysis)

• dermal stick (squeezing skin to obtain blood, it can cause plt clumps)

What does hematocrit measure?

percent area that is RBC

What is hemoglobin (Hgb)

the actual gas carrying dissolved pigment

What is the rule of three for Hgb?

the Hgb value is equal to three times the RBC count

What is the rule of three for hematocrit?

the Hematocrit value is equal to three times the Hgb value

sources of error for hematocrit

• incomplete sealing of hematocrit tubes

• inadequate centrifuging

• excess coagulant

what does MCV measure?

the size of the RBC

Normal ranges for MCV

80-100 FL

MCH normal values

27-32 pg

MCHC normal range

32-36%

What reagent is used for the Hgb test (cyanmethemoglobin method)?

Drabkin’s reagent

increased MCV

macrocytic

decreased MCV

microcytic

normal MCV

normocytic

MCV is increased in…

• Macrocytic anemia

• B12 and folate deficiency

• increased reticulocytes

MCV is decreased in…

• iron deficiency anemia

• thalassemia

MCH is increased in…

macrocytic anemias (b12 and folate deficiencies)

MCH is decreased in…

microcytic anemias (iron deficiency)

high MCHC

hyperchromic

low MCHC

hypochromia

normal MCHC

normochromic

MCV equation

Hematocrit (%) X 10 / RBC (coefficient)

MCH equation

Hemoglobin x 10 / RBC (coefficient)

MCHC equation

hemoglobin (g/dL) X 100 / hematocrit

What form does blood take during ESR?

Rouleau formation

ESR measures what?

non-specific inflammation

what plasma protein related factors increase ESR rate?

• high molecular weight proteins

• pathological paraproteins

• decrease in albumin

What plasma protein related factors decrease ESR?

• too much anti-coagulant

• inability to produce acute phase proteins

What RBC related factors decrease ESR?

• sickle cell

• spherocytosis

• microcytes

What RBC related factors increase ESR?

• macrocytosis

• severe anemia

• low hematocrit

• antibody coating of RBCs

What technical related factors decrease ESR?

• increase in anticoagulant/blood ratio

• low temp

What technical related factors increase ESR?

• rack not leveled

• vibration

• large change in room temp

• standing more than 60 min

normal ESR values for male <50

0-15mm/hr

normal ESR values for male >50

0-20 mm/hr

normal ESR values for female <50

0-20 mm/hr

normal ESR value for female >50

0-30 mm/hr

children normal ESR value

0-10 mm/hr

sources of error in ESR

• incompletely filled blood tube

• air bubbles

• fibrin clots

• storage of blood

• failing to set up test within 4 hours

• including buffy coat in reading

• direct sunlight

• drafts

what are the layers of the spun hematocrit?

• plasma

• buffy coat (white blood cells and platelets)

• RBCs

what percentage of spun blood is plasma?

55%

what percentage of spun blood is buffy coat?

1%

what percentage of spun blood is RBCs?

45%

Hgb function

transport oxygen from lungs to tissue and carbon dioxide from tissue to lungs

how is carboxyhemoglobin produced

• produced by the combination of Hgb and carbon monoxide (CO)

• it carries carbon monoxide

how can carboxyhemoglobin be increased?

individuals who smoke or are exposed to high levels of CO

how much of carboxyhemoglobin is normally found in RBC?

the concentration in a RBC is very low

how is methemoglobin formed

forms when ferrous iron of heme (Fe+2) becomes oxidized to ferric state (Fe+3)

what happens when methemoglobin is present in the RBC?

Hgb is unable to combine with O2 in this state

how much of methemoglobin is normally present

normally present in amounts of 1-2%

how can methemoglobin be increased?

ingestion or absorption of certain drugs / chemicals

how is sulfhemoglobin formed?

hemoglobin combining with sulfur

what is the production of sulfhemoglobin the result of?

ingestion of oxidizing drugs and can also be associated with chronic constipation

how much of sulfhemoglobin is normally present?

it is not normally present, however, when it is, it will last for the entire life of the RBC because of its good stability (this is not the case in a normal RBC)

which form of Hgb is not converted to cyanmethemoglobin?

sulfhemoglobin

what is hemoglobin composed of?

• heme (iron + protoporphyrin IX) + protein (globin)

• each Hgb has 4 heme groups and 4 globin chains

Hgb A

2 alpha, 2 beta chains

Hgb F

2 alpha, 2 gamma chains

Hgb A2

2 alpha, 2 delta chains

normal Hgb in a newborn (1-3 days)

14.5 - 22.5 g/dL

normal Hgb in children (2-12 years)

10.5 - 16 g/dL

normal Hgb in adult male

14-18 g/dL

normal Hgb in adult female

12-16 g/dL

sources of error due to technique for Hgb test

• improper pipetting

• failure to wash out pipet

• dirty/scratched cuvettes

• Drabkin's solution deterioration (not kept in dark)

sources of error due to patient condition for Hgb test

• lipemic samples

• elevated WBC counts

• presence of Hgb S or Hgb C (RBCs are resistant to lysis)

• elevated protein in serum that may precipitate (multiple myeloma)

what reagent is used for ESR

sodium citrate

what stain is used on body fluid?

wrights stain

what are the common body fluids used?

• pleural fluid

• pericardial fluid

• peritoneal fluid

• synovial fluid

• cerebrospinal fluid

dilution for clear body fluid

none

dilution for hazy body fluid

1/2

dilution for cloudy body fluid

1/5

dilution for bloody body fluid

1/10 with saline

normal synovial fluid RBC count

< 2000 / uL

normal synovial fluid WBC count

< 200 / uL

normal synovial differentials

• monocytes / macrophages 50-70%

• lymphocytes 20-40%

• neutrophils 5-15%

clinically significant differentials for synovial fluid

• increased neutrophils

• increased eosinophils

• increased RBCs

Normal seminal fluid RBC count

none

normal seminal fluid WBC count

some

Normal differential for seminal fluid

• some WBC

• some urethral epithelial

clinically significant differentials for seminal fluid

• > 1 million WBC / mL

• any RBC and bacteria

normal CSF RBC count

none

normal CSF WBC count

0-10 lymph or mono cells / uL

normal CSF differential

• neutrophils 0-6%

• monocytes 15-45%

• lymphocytes 40-80%

clinically significant differentials for CSF

• > 200 WBC / mL

• > 400 RBC / mL

• increased neutrophils, lymphocytes, RBCs, and bacteria

normal Pleural RBC count

< 100 RBCs /uL

normal pleural WBC count

< 1000 WBCs /uL

normal pleural differentials

• lymphocytes

• monocytes

• macrophages

• mesothelial lining cells

clinically significant Pleural differentials

• increased neutrophils

• increased eosinophils

• increased RBCs

normal Peritoneal WBC count

< 300 uL

normal Peritoneal differentials

• lymphocytes

• monocytes

• macrophages

• mesothelial lining cells

clinically significant Peritoneal differentials

• increased neutrophils

• increased RBCs

• increased eosinophils

what is the dilution used for the leuko-tik system for the manual WBC count?

sometimes 1:10, usually 1:20

what diluent is used for manual WBC count

• 2% acetic acid solution

• 1% HCL solution

universal formula for WBC count

#of cells counted x depth (10) x dilution factor (20) / area counted (4)

normal WBC values in adults

4.5 - 11 10^9 / L

normal WBC values in newborns

13-38 10^9 /L