AnemiaAnemia

Clinical Pathology Kristin Canga, RVT

Reading Assignment

• Page 68 – Lab Pro book• ‘Clinical Application’ box (Iron

Deficiency Anemia) on pg. 12 of A&P book

• Pages 55 – 57 Lab Pro book (about counting reticulocytes)

Anemia• Literally means “no blood” but clinically means

an ______________ ____________________below normal in any of the following values:– ________________________________________– ________________________________________– ________________________________________

• In other words, anemia is a condition of reduced oxygen carrying capacity of RBCs– Rate of RBC ______________________ = decreased– Rate of RBC ______________________ = increased

Aiding in Classification and Diagnosis of Anemia

• A thorough ___________ must be obtained.– This helps the doctor know: what the patient has been

____________ /____________, where they have been, how long they have been suffering, and possibly _________ the anemia has occurred.

• A physical exam should be completed.– Put your ____________ on the animal! – Look for _____________, _____________,

_____________, active bleeding, elevated heart/respiratory rates, etc…

• A complete _____________evaluation is a MUST.

Petechia

Ecchymosis

PATIENT HISTORY1. __________________________of clinical signs

– ______________ onset suggests acute _________________ or ______________

– ______________ onset suggests chronic ______________ or bone marrow depression

2. Evidence of blood loss– ______________ – ______________ – ______________ – Blood in ______________

PATIENT HISTORY3. ____________________________ 4. Existence of an underlying condition or prior illness

– ____________________________ – ____________________________ – ____________________________

5. Exposure to drugs - human ______________ , ______________

6. Exposure to toxic ______________ in the ______________ - ______________ , poisonous _________, ______________

PHYSICAL EXAMINTION1. ______________

– Suspect: infection, leukemia, hemorrhage, or hemolysis

2. Character of ___________________:– ______________ – ______________ – liver disease or hemolysis– ______________ + ______________ = hemolysis– ______________ - hypoxia– ______________ or ______________ = platelet or

vascular defect

PHYSICAL EXAMINATION3. Palpation

– ______________ – ______________ – ______________ – ______________

4. ______________ signs of underlying disease5. External wounds

– ______________ – ______________ – ______________

Classification and Dx of Anemia• Classification is to aid in discovering the _______________

and to help guide __________________.• Remember: Anemia is not a __________________, but a

sign of an underlying health concern.• Anemia may be considered ___________________ or

________________________ and is generally classified/diagnosed in one of two different ways:

1. By RBC ________ and ____ concentrationa. RBC ____________________ (MCV, MCHC)

2. By bone marrow responsea. ________________________________b. ________________________________

LABORATORY EVALUATIONInitial laboratory tests to evaluate the anemic patient

include (but not limited to):1. ______________ (and color of supernatent plasma)2. Total ______________ protein3. Examination of ______________ and

____________________________ 4. Total ______________ count5. ______________ estimation6. ______________ concentration7. Total ______________ count8. ______________ **9. ______________ evaluation **

PCV: Test yourself

• What is it measuring?• Normal ranges for dogs?• Normal ranges for cats• Plasma (supernatent) colors?

Plasma Protein

• What is it measuring?• How is it measured?• What is normal range for dogs and cats?

How Many Cells should you have?• As a rule, the following values should be considered:

– RBC total numbers should be in the ______________ . (106/μL)

– Plt total numbers should be in the ______________ of ______________ . (200,000 – 500,000/μL)

– WBC total numbers should be in the ______________ to ____________________________ . (6,000 – 17,000/μL)

• Neutrophils: 60 – 77%• Lymphocytes: 12 – 30%• Monocytes: 3 – 10%• Eosinophils: 2 – 10%• Basophils: rare (<2%)

In dogs and cats

Blood Film Evaluation and WBC Differential

• What area are you evaluating?• How are cells arranged?• Are RBCs normal?• How many WBCs are counted?• How many fields are counted for plt.

estimation?• What is calculation for plt. estimation?

Total WBC Count

• Overall count should be in ______________ to ____________________________ . (6,000-17,000)

• Total count calculated by machineManual hemacytometer is rare in clinic and diluent is no

longer available.

• Increased WBCs = ______________ • Decreased WBCs = ______________

Hemoglobin Calculation

• Done by machine.• Aids us in calculating average

______________ of RBCs (_______)• Aids us in calculating average ______

concentration within RBCs (_______) • Can aid in calculating average

______________ of Hb within average RBC. (_______) *** MCH is LEAST accurate***

Classifying Anemia by RBC indices• MCV: ____________________________• MCHC: ____________________________• MCH: ____________________________

Rules of Thumb (ROTs):• Hb concentration is ~_______ of PCV (in g/dL)• Total RBCs are ~_______ of PCV (in millions)

Classification by RBC Indicies• Recall that MCV (mean corpuscular volume)

describes the average volume of the individual RBC– Normal MCV = _____________________– Increased MCV = _____________________– Decreased MCV = _____________________

FORMULA: (PCV / Total RBC) X 10 = MCV (femtoliters)

Normal MCV = canine: 60 – 77 fl. feline: 40 – 55 fl.

Let’s do the math:• The MCV of a patient with a PCV of 12% is:

– Step 1: Recall the formula:• (_______/ ______________) X 10 = MCV (femtoliters)

– Step 2: Remember the ROT• total RBC ≅ _______ PCV so:• ______________ = ______________

– Step 3: plug in the numbers• ___________________________________• Is this normal for k9/fel? • How would you classify this RBC?

Possible Causes of Abnormal MCV• Possible causes of Increased MCV:

– Increased _____________________activity = #1• Reticulocytosis

– Congenital (___________&_________________)– Cats with _______ (+/- anemia)

• Possible causes of Decreased MCV:– ______________ deficiency = #1– Congenital disorder (_______and ______________)

Classification by RBC Indicies

• MCHC (mean corpuscular hemoglobin concentration):– Describes the ratio of the _______of hemoglobin to

the ______________in which it is contained (concentration of hemoglobin in the avg. RBC)

– Normal MCHC = ______________– Decreased MCHC = ______________– High MCHCs = artifact WHY???

Formula

(______ / ______) X ______= MCHC (g/dL)

Normal MCHC = canine: ______________g/dL feline: ______________g/dL

• Remember the ROTs?• If you calculate MCHC by estimating Hb, the

values will always come out the same.• Lets do the math!

Using the ROT• The MCHC of a patient with a PCV of 33% is:

– Step 1: Recall the formula• (_______ / _______) X _______= MCHC (g/dL)

– Step 2: Remember the ROT• Hb ≅ _______ of PCV so:• _______= _______• Step 3: Plug in the numbers• __________________________________________

Using actual numbers

• The patient’s Hb is 9g/dL, and their PCV is 30% • Formula: (_______/_______) x _______• SO: _______________________=_____g/dL

• Is this normal for k9? Fel?• How would it classify the RBC?

Low MCHC usually results from:

• Severe _______deficiency• Marked, regenerative anemia

– ____________________________RBCs that do not yet have their full complement of Hb.

MCHC increase:• Presence of ______________, ______________,

and ___________ can interfere with tests and ______________increase MCHC

• True _____________________anemia cannot exist; the erythrocyte cannot be oversaturated with ______.

Morphologic Classification of Anemia by RBC Indicies

MCHC normal MCHC decreased

MCV normal NormocyticNormochromic

NormocyticHypochromic

MCV increased MacrocyticNormochromic

MacrocyticHypochromic

MCV decreased MicrocyticNormochromic

MicrocyticHyprochromic

Normocytic ; Normochromic

Macrocytic Microcytic Hyperchromic Hypochromic

Calculating MCH• You will need to know HOW to do this for VTNE,

even though it is the _______accurate of the indices.

• Calculates the average _______of Hb contained in average RBC.

• (_______/_______) x _______= MCH in picograms (pg)– Normal ranges:

• K9: _______pg• Fel: _______pg

Let’s do the Math• The MCH of a patient with a PCV of 54% is:• Step 1: Remember the formula

– (_______/_______) x _______= MCH

• Step 2: Remember the ROT– Hb ≅ _______ PCV and RBCs ≅_______ PCV

• _______ = _______ and _______ = _______

• Step 3– Plug in the numbers:

• _____________________pg

Diagnosis of Anemia According to Bone Marrow Response

• Most applicable way to differentiate between:– ________________________ and

________________________ anemia

Bone Marrow Response

Regenerative anemia– Characterized by evidence of increased ______________

and delivery of new erythrocytes into ______________ (usually within 2-4 days).

– Usually suggests bone marrow is responding appropriately to either:

• _____________________ (acute or chronic; internal or external) or

• _____________________ (intravascular or extravascular)– Involves determining whether absolute

_____________________ numbers are increased in the blood.

Bone Marrow Response

Non-regenerative anemia– Lack of circulating ______________ RBCs in the face

of _______ indicates a nonregenerative anemia and likely results from bone marrow ______________.

• Either reduced erythropoiesis or defective erythropoiesis

– No response evident in ______________blood. (usually ______________; ______________)

– _____________________examination may be helpful with the diagnosis.

Regenerative Anemia1.1. Blood Loss Anemia Blood Loss Anemia

Acute _____________________– relatively large amount of blood lost in a brief period. (______________; ______________)

– PCV initially = ______________– Reticulocytes should appear ~_______ hrs (peak

within ~ 1 week)– Causes:

a. ______________– Internal or external– Accidental or surgical

b. ______________disordersc. Bleeding ______________ or large ______________

Regenerative AnemiaChronic blood loss (_______Deficiency Anemia) – lost

______________and ______________for a period of time.a. Parasites

– ______________, _______, blood-sucking _______, coccidia spp.

b. GI ulcers and neoplasmsc. Inflammatory bowel diseased. Overuse of ______________donors

• Note: neonates can become iron deficient due to lack of adequate dietary _______ intake.

Iron Deficiency Anemia• Body compensates for anemia by lowering _______-

_______ affinity, preferential shunting of blood to vital _______, increased ______________output (tachycardia), and increased levels of _____________________.

• With decreasing _______ stores, erythropoiesis is limited and RBC’s become ______________and deficient in _______ (______________and _____________________).– Hallmark of iron deficiency anemia is decreased _______.

• Keratocytes & schistocytes • Clinical signs include: lethargy, weakness, decrease Clinical signs include: lethargy, weakness, decrease

exercise tolerance, anorexia, lack of grooming, mild exercise tolerance, anorexia, lack of grooming, mild systolic murmursystolic murmur..

Regenerative Anemia• 2. _____________________: increased rate of

erythrocyte _______________________ within the body.a. Immune-mediated

-_____________________-_____________________- Incompatible _____________________

a. Blood Parasites-Hemotrophic Mycoplasmas- ______________________spp.- ________________________

Cytauxzoon felis inclusions

Regenerative Anemia

c. Heinz body anemia– Plants

• Onions*, garlic– ______________________

– Drugs or Chemicals• (______________________, Propylene glycol, Zinc,

Copper, Methylene blue, Naphthalene, ______________________, phenothiazine, benzocaine

– Diseases (in cats)• Diabetes mellitus• Hyperthyroidism• Lymphoma

Regenerative Anemia

d. ______________________ induced hemolysisRBC glycolysis is inhibited by hypophosphatemia;

no glycolysis = no ATP (energy) for RBC = cell lysis

• Diabetic cats• Enteral alimentation

Regenerative Anemiae. Other Microorganisms

– ______________________• Clostridium spp. and Leptospirosis (cattle)

– ______________________• ______________________

f. ______________________intoxication (usually calves)– can also occur as a result of inappropriate administration of

______________________ therapy.g. ______________________ RBC defects

– ______________________ (shortened RBC lifespan)– RBC membrane transport defects– Chronic intermittent hemolytic anemia (Abyssinian and

Somali cats)

Regenerative Anemia

h. Miscellaneous– Metabolic disorders (anything that interferes with

synthesis of ______________________, RBC, etc. or anything that interferes with ______________________processes of RBC)

Non-regenerative Anemia• Most non-regenerative anemias are

______________________• Further sub-classified based on whether

______________________ (neutrophil production) and ______________________ (platelet production) are also affected.

• Animals with non-regenerative anemia in conjunction with ______________________ (neutropenia and thrombocytopenia) usually have ____________ cell injury.– Possible causes: drugs, toxins, viruses (FeLV), radiation,

and immune-mediated stem cell injury.

Non-regenerative Anemia1. Reduced ______________________

a. Chronic ______________________ diseaseb. Endocrine deficienciesc. Inflammation and neoplasiad. Cytotoxic damage to the

______________________• Estrogen toxicity• Cytotoxic cancer drug therapy• Chlormphenicol (cats)• Radiation• Other drugs

Non-regenerative Anemiae. Infectious agents

– FeLV– ______________________ spp.– ______________________

f. Immune-mediated – Continued treatment with recombinant erythropoietin– ______________________ aplastic anemia

g. Congenital/inheritedh. ______________________ and other

______________________ disorders

Non-regenerative Anemia2. Defective ______________________

a. Disorders of ___________ synthesis– Iron, copper, and pyridoxine deficiencies; lead toxicity; drugs

b. Folate and ____________ deficienciesc. Abnormal ______________________

• can be inherited, drug-induced or idiopathic

Reticulocyte Count

• Probably the most important diagnostic tool used in the evaluation of anemia.

• Fewer _____________ erythrocytes are present in anemic animal; more ______________________are present.

• Expressed as a _____ of the RBCs present.• The lifespan of a normal RBC is about 110 days

(dogs) and 68 days (cats).– Bone marrow should replace ___ % of the RBCs daily

so the reticulocyte count should be _____-______%.

Reticulocyte Count

1. Gently mix 4 drops of blood with 4 drops of new methylene blue in a test tube.

2. Let mixture stand for 15 minutes3. Use 1 drop of mixture to prepare a diagnostic

blood film and observe under high-power, oil-immersion field.

4. Count 1,000 RBCs while separately keeping track of the number of reticulocytes (only aggregate form)

5. Divide the reticulocyte number by 1,000 and convert to a percentage. (Multiply by 100)

Example Reticulocyte count

• If you see 10 retics on slide 1 and 15 on slide 2, your total is 25 reticulocytes.

• 25/1000 = 0.025 x 100 = 2.5%

Corrected Reticulocyte Count• Performed to take in account the reduced number of circulating

RBC’s in the anemic animal.– Called CRC or Corrected Reticulocyte Count– FORMULA:

• Observed retics % x PCV / normal PCV• (Normal PCV: use 45% for dogs and 35% for cats)

Ex: 2.5% X 30% / 45% = 1.67%

Note: This calculation is necessary because the reticulocyte count is misleading in anemic patients. The problem occurs because the reticulocyte count is not really a count but rather a percentage: it reports the number of reticulocytes as a percentage of the number of red blood cells. In anemia, the patient's red blood cells are reduced, creating an elevated reticulocyte count.