Blood Investigation

7/30/2019 Blood Investigation

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Blood Tests

Complete Blood Count (CBC) which

includes:- Hemoglobin

• Hgb test is a measure of the total amount of hemoglobin in the blood

Hematocrit

• Hct measures the percentage of red blood cellsin the total blood volume



RBC count

• The number of RBC per cubic millimeter

(mm3) of whole blood

WBC or leukocyte

• The number of circulating WBC per cubic

millimeter of whole blood



Serum Electrolytes

• Ordered as a screening test for electrolyte andacid – base imbalance.

• The most commonly ordered serum tests arefor “ sodium, potassium, chloride , and bicarbonate”

• Evaluate renal function “ Urea, Creatinine” • Urea, the end product of protein metabolism ismeasured as BUN. Creatinine is produced inrelatively constant quantities by the muscles

and is excreted by the kidneys.



Serum Osmolality

• Serum Osmolality: is a measure of the solute

concentration of the blood. The particlesincluded are sodium ions, glucose, and urea.

• It is estimated by doubling the serum sodium

• Serum Osmolality values are used to evaluatefluid balance

• Normal values are 280-300 mOsm/kg.

• An increase in Osmolality indicates a fluid

volume deficit



Drug monitoring

Is conducted when the client is taking a

medication with narrow therapeutic range suchas digoxin.

• This includes monitoring drawing blood

samples for peak and trough levels todetermine if the blood serum levels of aspecific drug are at a therapeutic level and nota sub therapeutic or toxic level.

• Peak level: the highest concentration of thedrug in the blood serum

• Trough level: lowest concentration



Arterial Blood Gases “ABGs”

• Take specimen of the ABG from the radial, Brachial,

femoral arteries.

• Need to apply pressure to the puncture side for about

5-10 minutes after removing the needle.



Blood Chemistry

• Certain enzymes such as Lactic dehydrogenase“LDH”, Creatine Kinase “CK” , serumglucose, hormones such as thyroid hormone,cholesterol and triglycerides.

• A common test is the glycosylate hemoglobin“HbA1C”, which is a measurement of bloodglucose that is bound to hemoglobin. HbA1C

is reflection of how well blood glucose levelshave been controlled during the prior 3 to 4months.



Capillary Blood Glucose

• Measure blood glucose when frequent tests are

required or a veinpuncture cannot be performed.

• Less painful, easily performed



Specimen Collection

Nurses always assume the responsibility for specimen

collection depending on the type of specimen and

skill required.



Nursing responsibilities with specimencollection

• Explain the purpose of specimen collection

and the procedure for obtaining the specimen.• Provide client comfort, privacy, and safety.

• Use the correct procedure for obtaining the

specimen collection.• Note relevant information on the laboratoryrequisition slip such as medication the client istaking that may affect the results.

• Transport the specimen to the laboratory promptly to have more correct results.

• Report abnormal results to the health care provider



The CBC interpretation are useful in

the diagnosis of various types of anemias.

It can reflect acute or chronic

infection, allergies, and problemswith clotting.



• Component of the CBC:

• Red Blood Cells (RBCs)

• Hematocrit (Hct) • Hemoglobin (Hgb) • Mean Corpuscular Volume (MCV) • Mean Corpuscular Hemoglobin

Concentration (MCHC)- Red cell distribution width (RDW)

• White Blood Cells (WBCs)

• Platelet



• RBC (varies with altitude):

– M: 4.7 to 6.1 x10^12 /L

– F: 4.2 to 5.4 x10^12 /L• Biconcave disc shape with diameter

of about 8 µm

• Function: - transport hemoglobinwhich carries oxygen from the lung tothe tissues

-acid –base buffer.

• Life span 100-120 days.



Hemoglobin :

M: 13.8 to 17.2 gm/dL

F: 12.1 to 15.1 gm/dL

Hematocrit : (packed cell volume)

It is ratio of the volume of red cell tothe volume of whole blood.

M: 40.7 to 50.3 %

F: 36.1 to 44.3 %



– MCV = mean corpuscular volumeHCT/RBC count= 80-100fL• small = microcytic

• normal = normocytic

• large = macrocytic

– MCHC= mean corpuscular hemoglobinconcentration HB/RBC count= 26-34%• decreased = hypochromic

• normal = normochromic



• MCH (mean corpuscular hemoglobin)

HB/HCT = 27-32 pg

• RDW (red cell distribution width)

• It is correlates with the degree of anisocytosis

_ Normal range from 10-15%



• This important value is needed in the evaluationof any anemia.

• Normal range 1-2%

• Retic count goes up with

– Hemolytic anemia

• Retic goes down with – Nutritional deficiencies

_ Diseases of the bone marrow itself



Definition of Anaemia

• Decrease in the number of circulating red blood

cell mass and there by O2 carrying capacity

• Most common hematological disorder by far• Almost always a secondary disorder

• As such, critical for all practitioners to know

how to evaluate / determine its cause / treat



Types of Anaemia



Screening Tests – Anaemia

• Clinical Signs and symptoms of Anaemia

• Look for bleeding – all possible sites

• Look for the causes for anemia

• Routine Hemoglobin examination

• Cut off marks for Hb –

– US < 13.5 g WHO < 12.5 g

– Subcontinent Less than 12 g%



Clinical Signs to be looked for

• Skin / mucosal pallor,

• Skin dryness, palmar creases

• Bald tongue, Glossitis

• Mouth ulcers, Rectal exam

• Jaundice, Purpura

• Lymphadenopathy

• Hepato-splenomegaly• Breathlessness

• Tachycardia, CHF

• Bleeding, Occult Blood



PCV or Hematocrit

• 57% Plasma

• 1% Buffy coat – WBC

• 42% Hct (PCV)



The Three Basic Measures

Measurement Normal

Range

A. RBC count 5 million 4 to 6

B. Hemoglobin 15 g% 12 to 17

C. Hematocrit 45 38 to 50

A x 3 = B x 3 = C - This is the rule of thumbCheck whether this holds good in given results

If not -indicates micro or macrocytosis or

hypochromia.



Causes of Anaemia

1. Decreased production of Red Cells

- Hypoproliferative, marrow failure

2. Increased destruction of Red Cells

- Hemolysis (decreased survival of RBC)

3. Loss of Red Cells due to bleeding

- Acute / chronic blood loss (hemorrhagic)



Anaemia – First Test

RETICULOCYTE COUNT %

Normal

Less than 2%

• „RBC to be‟ or Apprentice RBC • Fragments of nuclear material

• RNA strands which stain blue



Reticulocytes

Leishman’s Supravital



Anaemia

Hypoproliferative Hemolytic

Retics < 2 Retics > 2

Hb% < 12, Hct < 38%



Workup – Second Test

• The next step is ‘What is the size of RBC’ ?

• MCV indicates the Red cell volume (size)

• Both the MCH & MCHC tell Hb content of RBC• If the Retic count is 2 or less

• We are dealing with either

– Hypoproliferative anaemia (lack of raw material) – Maturation defect with less production

– Bone marrow suppression (primary/ secondary)



Mean Cell Volume (MCV)

• RBC volume (rather) is measured by

• The Mean Cell Volume or MCV and RDW

Microcytic

< 80 fl

MCV

Normocytic Macrocytic

80 -100 fl > 100 fl

< 6.5 µ 6.5 - 9 µ > 9 µ



Anaemia Workup - MCV

Microcytic

MCV

Normocytic Macrocytic

Iron Deficiency IDA

Chronic Infections

Thalassemias

Hemoglobinopathies

Sideroblastic Anemia

Chronic disease

Early IDA

Hemoglobinopathies

Primary marrow disorders

Combined deficiencies

Increased destruction

Megaloblastic anemias

Liver disease/alcohol

Hemoglobinopathies

Metabolic disorders

Marrow disorders

Increased destruction



Red cell Distribution Width - RDW

Normal

Population

Uniform

RDW

High

Population

Double



Anaemia Workup - 4th Test

Peripheral Smear Study

• Are all RBC of the same size ?

• Are all RBC of the same normal discoid shape ?

• How is the colour (Hb content) saturation ?

• Are all the RBC of same colour/ multi coloured ?

• Are there any RBC inclusions ?

• Are intra RBC there any hemo-parasites ?

• Are leucocytes normal in number and D.C ?

• Is platelet distribution adequate ?



Microcytic Hypochromic - IDA



IDA – Special Tests

Iron related tests Normal IDA

Serum Ferritin (pmo/L) 33-270 < 33

TIBC (µg/dL) 300-340 > 400

Serum Iron (µg/dL) 50-150 < 30

Saturation % 30-50 < 10

Bone marrow Iron ++ Absent



IDA Summary

• Microcytic MCV < 80 fl, RBC < 6 µ

• RDW Widened with low MCV

• Hypochromic MCH < 27 pg, MCHC < 30%

• RI < 2

• Serum ferritin Very low < 30 (p mols/L)

• TIBC Increased > 400 (µg/dL)

• Serum Iron Very low < 30 (µg/dL)• BM Fe Stain Absent Fe

• Response to Fe Rx. Excellent



IDA- Some Nuggets

• Look for occult blood loss – 2 days non veg. free• Pica and Pagophagia – Ice sucking

• Absorption of Haem Iron > Fe ++ > Fe+++

• Food, Phytates, Ca, Phosphate, antacids↓absorption

• Ascorbic acid↑absorption

• Oral iron Rx. always is the best, ? Carbonyl Fe

• FeSO4 is the best. Reserve parenteral Rx.

• Packed cell transfusion in emergency• Continue Fe Rx at least 2 months after normal Hb

• 1 gram↑in Hb every week can be expected

• Always supplement protein for the Globin component



Microcytic Anaemias

MCV < 80 flSerumIron

TIBC BM Perls stain

Iron Def. Anemia

↓↓ ↑↑

0

Chronic Infection ↓↓ ↓↓ + +

Thalassemia ↑↑ N + + + +

Hemoglobinopathy N N + + Lead poisoning N N + +

Sideroblastic ↑↑

N + + + +



Macrocytic Anaemias

A. Megaloblastic Macrocytic – B12 and Folate↓ B. Non Megaloblastic Macrocytic Anaemias

1. Liver disease/alcohol

2. Hemoglobinopathies

3. Metabolic disorders, Hypothyroidism

4. Myelodystrophy, BM infiltration

5. Accelerated Erythropoesis -

↑destruction6. Drugs (cytotoxics, immunosuppressants, AZT,

anticonvulsants)



Anemia - Macrocytic (MCV > 100)

Premature gray hair – consider MBA

Macrocytic anemias may be asymptomatic until

the Hb is as low as 6 gramsMCV 100-110 fl

must look for other causes of macrocytosis

MCV > 110 flalmost always folate or B12 deficiency



Macrocytosis -MBA



HSN - MBA



Basophilic Stippling - MBA

BS occurs in Lead poisoning also



MBA - BM



Pernicious Anaemia - Tongue

Bald, smooth, lemonyellowish red tongue



Normocytic Anaemias

1. Chronic disease

2. Early IDA

3. Hemoglobinopathies

4. Primary marrow disorders

5. Combined deficiencies

6. Increased destruction

7. Anaemia of investigations -ICU



Anaemia of Chronic Disease

• Thyroid diseases

• Malignancy

• Collagen Vascular Disease – Rheumatoid Arthritis

– SLE

– Polymyositis – Polyarteritis Nodosa

• IBD

– Ulcerative Colitis

– Crohn‟s Disease

• Chronic Infections

– HIV, Osteomyelitis

– Tuberculosis• Renal Failure

‘Di hi ’ A i



‘Dimorphic’ Anaemia

• Folate & Fe deficiency (pregnancy, alcoholism)

• B12 & Fe deficiency (PA with atrophic gastritis)

• Thalassemia minor & B12 or folate deficiency• Fe deficiency & hemolysis (prosthetic valve)

• Folate deficiency & hemolysis (Hb SS disease)

• Peripheral smear exam is critical to assess these• RDW is increased very much

RBC Si A i t i



RBC Size – Anisocytosis

Different sizes of RBC

P ikil t i



Poikilocytosis

Different Shapes of RBC



Polychromasia - Spherocytosis



Target Cells

1. Liver Disease

2. Thalassemia

3. Hb D Disease

4. Post splenectomy



• WBCs are involved in the immune response.

• The normal range: 4 – 11x10^9 /L

• Two types of WBC:

1) Granulocytes consist of: – Neutrophils: 50 - 70%

– Eosinophils: 1 - 5%

– Basophils: up to 1%

2) Agranulocytes consist of:- Lymphocytes: 20 - 40%

– Monocytes: 1 - 6%



The type of cell affected depends upon its primary

function:

In bacterial infections, neutrophils are most

commonly affected

In viral infections, lymphocytes are most

commonly affected

In parasitic infections, eosinophils are most

commonly affected.



• polymorphneuclear leukocytes(PMN,s)

• Nucleus 3-5 lobes.

• Diameter 10-14 µm

• 50-70% WBC

=2.5-7.5x10^9/ L

• Function: Phagocytosis of bacteriaand cell debris

• Numbers rise with all manner of

stress, especially bacterial infections



• Neutrophil disorders

– Neutrophilia – an increase in neutrophils

– Conditions associated with neutrophilia are:

1-Bacterial infections (most common cause)

2-Tissue destruction

e.g. tissue infarctions, burns.

3- leukemoid reaction

4-Leukemia



– Neutropenia – this may result from

1-Decreased bone marrow production

e.g. BM hypoplasia.

2-Ineffective bone marrow production

– E.g. megaloblastic anemias and

myelodysplastic syndromes.

3- post acute infection

_ e.g. typhoid fever, brucellosis.



• Bilobed nucleus

• 1-5% of WBC

=0.04-0.4x10^9/L

• Diameter about 10-14 µm

• Function: Involved in allergy, parasiticinfections

• Contains: eosinophilic granules



– Eosinophilia may be found in

• Parasitic infections

• Allergic conditions andhypersensitivity reaction



• No specific granules

• 20-40% of WBC

=1.55-3.5x10^9/ L

• Diameter 8-10 µm

• T cells: cellular

• (for viral infections)

• B cells: humoral(antibody)

• Natural Killer Cells



• Lymphocytosis – may indicate _ Viral infection

e.g. Infectious mononucleosis, CMV or pertussis.

_ Bacterial infectione.g. TB

• Lymphopenia – caused by

_Stress.

_Steroid therapy

_ Irradiation



• (Leukocytosis) may indicate: _ Infectious diseases

_Inflammatory disease (such as rheumatoidarthritis or allergy)

_Leukemia _Severe emotional or physical stress

_Tissue damage (e.g. necrosis,or burns)

• (Leukopenia) may result from: _ Decreased WBC production from BM.

_ Irradiation.

_ Exposure to chemical or drugs.



• Fever • Malaise

• Weakness

• Others depend on each system which is involved

e.g. » chest: cough, SOB and chest pain» abdomen: diarrhea, vomiting,dehydration.

»CNS: headache, visual disturbance,

Neck stiffness

and so 0n.



• Infection of the mouth and throat.

• Painful skin ulceration.• Recurrent infection.

• Septicemia.



•Small granular non-nucleated

discs.

•Diameter about 2-4 µm

•Normal range; 150-300x10^9 /L•Destroyed by macrophage cells in

the spleen.

•Function; involved in coagulation

and blood haemostasis.

•Life span 7-10 days



• Numbers of platelets – Increased (Thrombocythemia)

• Pregnancy.

• Exercise.

• High attitudes.• splenectomy

– Decreased (Thrombocytopenia)• Menstruation.

• Haemorrhage.

• Bone marrow destruction or suppression e.g. leukemia

• The values have to fit the clinical situation.



• Petechial hemorhage.

• Easy bruising.

• Mucosal bleeding

e.g. _ epistaxes.

_ gum bleeding

Blood Investigation

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