BLOOD INVESTIGATIONS

IN

DENTAL PRACTICE

Presented by:

Dr.Ayesha Taha

JR I

Department of Pedodontics

and Preventive Dentistry

SPPGIDMS, Lucknow

CONTENT

INTRODUCTION

HAEMOSTASIS

SIGNIFICANCE OF BLOOD INVESTIGATION

COLLECTION OF BLOOD SAMPLE

TYPES OF HEMATOLOGICAL INVESTIGATIONS

•Complete Blood Count

•WBC count

•Differential Leukocyte count

•Hemoglobin

•Hematocrit

•Erythrocytes indices

•Platelets

•Bleeding time

•Capillary Fragility Test

•Clotting Time

•Erythrocyte Sedimentation Rate

HEMATOLOGICAL INVESTIGATIONS (not so

frequent in dentistry)

•Prothrombin Time

•Partial Thromboplastin Time

•INR

OTHER BLOOD TESTS

DENTAL MANAGEMENT OF BLEEDING DISORDER

CONCLUSION

Various laboratory Investigations are sometimes required

for diagnosis and treatment planning of disorder related to

oral cavity.

These can detect abnormalities such as

• Infection

•Anaemia

•Allergies

Blood is also examined for grouping and cross-matching

INTRODUCTION

A NORMAL TEST result is just as significant as an abnormal

result.

A normal result does not mean that the test was unnecessary.

When a result is normal, it not only helps to rule out diseases,

but it also establishes a baseline for the clinician.

Either whole blood is used to count blood cells, or the blood cells

are separated from the fluid that contains them. This fluid is called

Plasma or Serum.

• Blood to be separated for serum

samples is collected in a plain clotting

tube (containing beads treated with a

clotting activator).

•Blood NOT to be separated for serum

samples is collected in a tube containing

lithium heparin (or beads treated with

lithium heparin).

1. Vascular phase :Vasoconstriction, immediately

2. Platelet phase : Adhesion & aggregation,Platelet plug

formation.

3. Coagulation phase : later, contains extrinsic & intrinsic

pathways

4. Metabolic (fibrinolytic) phase: release antithrombotic

agents.

HAEMOSTASIS

SIGNIFICANCE OF BLOOD INVESTIGATION

Blood investigation helps in diagnosing

• Leukopenia

• Thrombocytopenia

• Myeloma

•Anemia *Iron deficiency

*Aplastic

*Sickle cell anemia

• Thalassemia

•Acute and Chronic leukemia

• liver disease

• Myxedema

•Diabetes

COLLECTION OF BLOOD SAMPLE

•CAPILLARY BLOOD

SPECIMENS: The specimen is

obtained by pricking the patient`s

finger .

•VENOUS BLOOD SPECIMEN:

Most Commonly used method.

Venipuncture is usually performed

in ANTECUBITAL vein.

•WBC count

•Differential

Leukocyte count

•RBC count

•Hemoglobin

•Hematocrit

•Erythrocytes indices

•Platelet Count

•Bleeding time

•Capillary Fragility Test

•Clotting Time

•Erythrocyte Sedimentation Rate

TYPES OF HEMATOLOGICAL INVESTIGATIONS

Complete Blood Count

COMPLETE BLOOD COUNT

Complete blood count (CBC) is one of the most commonly ordered

blood tests.

The complete blood count is the calculation of the cellular (formed

elements) of blood.

What are the components of the complete blood count (CBC)?

The complete blood count, or CBC, lists a number of many

important values. Typically, it includes the following:

• White blood cell count (WBC or leukocyte count)

• WBC differential countWBC

• Red blood cell count (RBC or erythrocyte count)

• Hematocrit (Hct)

• Hemoglobin (Hbg)

• Mean corpuscular volume (MCV)

• Mean corpuscular hemoglobin (MCH)

• Mean corpuscular hemoglobin concentration (MCHC)

RBC

• Platelet countPLATELET

•White blood cell count (WBC) is the number of white

blood cells in a volume of blood.

•This can also be referred to as the Leukocyte Count

•It can be expressed in international units =

4.3 to 10.8 x 109 cells per liter.

• Normal range of WBC=

4,500 - 10,000 cells/mm3 of blood.

•Number of cells are usually counted with the help of

Neubauer’s counting chamber

WBC/Leukocyte Count

A high white blood cell count usually indicates:

1. An increased production of white blood cells to fight an

infection

2. A reaction to a drug that increases white blood cell

production

3. A disease of bone marrow, causing abnormally high

production of white blood cells

4. An immune system disorder that increases white blood cell

production.

Specific causes of Leukocytosis:

1. Infection- Acute and Chronic

2. Leukaemia

3. Polycythemia

4. Trauma

5. Exercise , Stress and fear

6. After general anesthesia

7. Allergy

8. Drugs, such as corticosteroids and epinephrine

9. Rheumatoid arthritis

10. Smoking

Specific causes of Leukopenia:

1. Aplastic anaemia

2. Influenza, measles and Respiratory tract infection

3. Catarrhal Jaundice

4. Early Leukaemia

5. Depression of Bone marrow

6. Drug and chemical toxicity

7. Shock

WBC

Granulocytes

Neutrophils Eosinophils Basophils

Agranulocytes

Lymphocytes Monocytes

White blood cell (WBC) differential count:

White blood cells are comprised of several different types of

cells that are differentiated, or distinguished, based on their size

and shape.

Differential Count WBC

Normal values:• Granulocytes (or polymorphonuclears)

Neutrophils:2.0–7.0×109/l (40–80%)

Eosinophils: 0.02–0.5×109/l (1–6%)

Basophils: 0.02–0.1×109/l (< 1–2%)

• Agranulocytes (or mononuclear)

Lymphocytes: 1.0–3.0×109/l (20–40%)

Monocytes: 0.2–1.0×109/l (2–10%)

CLINICAL SIGNIFICANCENeutrophils

INCREASES in: DECREASES in:

Inflammatory disease Aplastic Anaemia

Stress Cyclic Neutropenia

Exercise Malignant Neutropenia

Pregnancy Early Leukemia

Infection

Excitement

Eosinophils

INCEASES in: DECREASES in:

Parasitic infections Immune defect

Hypersensitivity/ Acute stress

Allergic responses Typhoid Fever

Scarlet Fever Aplastic Anaemia

Basophils

INCREASES in: DECREASES in:

Chronic leaukemia Acute Infection

Myelofibrosis Severe injury

Polycythemia

Lymphocytes

INCEASES in: DECREASES in:

Lymphocytic Leukemia Aplastic Anaemia

Mumps

Whooping Cough

Chronic Infection

•Monocytes

INCREASES in: DECREASES in:

Hodgkin disease Aplastic Anaemia

Monocytic Anaemia Acute Leukemia

Malaria – Kala Azar

SABE

TB

RBC Count

•Red Blood cell count (RBC) signifies the number of red blood

cells in a volume of blood.

• Normal range : 4.2 to 5.9 million cells/cmm.

• This can also be referred to as the Erythrocyte count

• It can be expressed in international units:4.2 to 5.9 x 1012 cells

per liter.

•An increase in red blood cell mass is known as Polycythemia.

•Polycythemia Vera is a disease of unknown origin that results in an

abnormal increase in red blood cells.

•CAUSES:

•Normal physiological increases in the RBC count occurs at high

altitudes or after strenuous physical training.

• Drugs: Gentamicin

Methyldopa

•Smokers also have a higher number of red blood cells than non-

smokers.

INCREASE in RBC Count

DECREASE in RBC Count

•Massive RBC loss, such as acute hemorrhage

• Abnormal destruction of red blood cells

• Lack of substances needed for RBC production

• Chemotherapy or radiation side effects from treatment of bone

marrow malignancies such as leukemia can result in bone marrow

suppression.

HEMOGLOBLIN

Hemoglobin is the protein molecule within red blood cells that

carries oxygen and gives blood its red color.

•Normal range =13-18 grams per dl for men and

12-16 grams per dl for women

•International units= 8.1 to 11.2 millimoles/L for men

7.4 to 9.9 milimoles/L for women

Increase in Hb

*Benign neoplasm of brain and CNS*Carcinoma of the kidney* Cholera*Diarrhoea*Pheochromocytoma*Polycythemia vera

Decrease in Hb

*Aplastic anaemia

*Anti-retroviral drugs for HIV infection Cirrhosis

*Hodgkin's lymphoma

*Hypothyroidism

*Kidney disease

*Lead poisoning

*Leukaemia

*Multiple myeloma

*Vitamin deficiency

anaemia

A low haemoglobin count can also be due to blood loss

Diseases and conditions that cause the body to destroy red

blood cells faster than they can be made:

• Enlarged spleen (splenomegaly)

• Sickle cell anemia

• Thalassemia

• Vasculitis

•It is a measure of volume percent of packed red blood cells to

that of whole blood.

•This is usually measured by spinning down a sample of blood

in a test tube, which causes the red blood cells to pack at the

bottom of the tube.

Normal results :

Male: 40.7 - 50.3%

Female: 36.1 - 44.3%

Hematocrit (Hct)

High Hematocrit may be due to:

•Congenital heart disease

•Cor pulmonale

•Dehydration

•Erythrocytosis

•Low blood oxygen levels (hypoxia)

•Pulmonary fibrosis

•Polycythemia vera

Low Hematocrit may be due to:

•Anaemia

Erthrocytes Indices

•To evaluate the nature of Anaemia, assistance is obtained by

calculating standard indices relating to the size of RBCs.

•By measuring these indices we can classify anaemia as

Microcytic, Macrocytic And Normocytic and Hypochromic

and Normochromic.

Types

MCH MCHC MCV

The Haemoglobin content of erythrocyte is referred to as the Mean

Corpuscular Haemoglobin(MCH) expressed in picogram of

haemoglobin per cell.

MCH = Haemoglobin concentration (g/dl) × 100

RBC in million/mm3

Mean Corpuscular Haemoglobin (MCH)

The concentration of Haemoglobin in the erythrocyte is referred to

as the Mean Corpuscular Haemoglobin Concentration.(MCHC)

expressed in picogram of haemoglobin per cell.

MCHC = Haemoglobin concentration (g/dl) × 100

Hematocrit

Mean Corpuscular

Haemoglobin Concentration (MCHC)

The average red cell volume is referred to as the Mean Corpuscular

Volume(MCV) .

It is expressed in cubic microns per cell.

MCHC = Hematocrit × 100

RBC in million /mm3

Mean Corpuscular Volume (MCV)

Different types of Anaemia and Indices

Types of

Anemia

MCV MCH MCHC

Microcytic

Hypochromic

Decreased Decreased Decreased

Macrocytic

Normochromic

Increased Increased Normal

Normocytic

Normochromic

Normal Normal Normal

The common causes of Microcytic & Hypochromic Anemia

(decreased MCV and MCH) are:

•Iron deficiency anemia

•Anemia of chronic disease

•Thalassemia

•Sideroblastic anemia

The common causes of Macrocytic Anemia (increased MCV

and MCH) are as follows:

•Folate or Vit B12 deficiency anemia

•Liver disease

•Hemolytic or Aplastic anemias

•Hypothyroidism

•Excessive alcohol intake

•Myelodysplastic syndrome

The common causes of Normocytic And Normochromic

Anemia (normal MCV, MCH and MCHC) are:

•Anemia of chronic disease

•Acute blood loss

•Hemolytic anemia, such as autoimmune hemolytic anemia,

hereditary spherocytosis, or nonspherocytic congenital hemolytic

anemia (G6PD deficiency, other)

•Anemia of renal diseases.

PLATELET/THROMBOCYTE COUNT

The number of platelets in a specified volume of blood.

Platelets play a vital role in Haemostasis.

Normal range (Adult) =150,000 to 400,000/ cmm of blood.

(150 to 400 x 109/ L)

Normal range(Children) =150,000-450,000 /cmm of blood.

(150-450 x 109/L)

Interpretation of Platelet count

THROMBOCYTOSIS:

Post operative phase

Pregnancy

Post partum phase

Haemolytic Anemia

Trauma

Polycythemia vera

Chronic myelocytic leukemia

THROMBOCYTOPENIA:

Acute leukemia

Idiopathic thrombocytopenic

purpura

Aplastic anemia

Effect of chemotherapy

Hypersplenism

It Measures the time required for hemostatic plug to form.

Lack of any clotting factor or platelet abnormalities will

prolong the bleeding time.

It is used to screen disorders of platelet function and

thrombocytopenia

Normal Bleeding Time: 2 - 6 minutes

Methods are: Duke method and Ivy’s method

Bleeding Time

An abnormal Bleeding time- It is usually the result of

abnormalities in the structure / abilities of capillaries to contract

or abnormalities in the number (Thrombocytopenia) and

functional integrity of platelets.

Interpretation of bleeding time

•It is the test of the ability of superficial capillaries of the skin

and forearm and hands to withstand an increased intraluminal

pressure and a certain degree of hypoxia.

•It is a clinical diagnostic method to determine hemorrhagic tendency.

It is done by occluding the upper veins of the upper arm

with a blood pressure cuff for five minutes.

Also known as Tourniquet Test/ Rumpel Leede Test

Positive result: unequivocal petechiae seen distal to cuff.

Negative result: If only 1 or 2 petechiae seen distal to cuff.

Capillary Fragility Test

Time required for coagulation to occur in a sample of whole

blood outside the body is known as Clotting Time.

Normal time- 3 to 7 minutes

Method are:

• Capillary tube method

• Le and white’s test tube method

Clotting Time

An abnormal Clotting time- It is usually prolonged in diseases

affecting stages of coagulation.

It is also increased in:Cirrhosis

Hemophilia A and B

Factor XI deficiency,

Hypofibringenemia and

Heparin & Dicumarol therapy.

Interpretation of Clotting time

•It is the measure of the rate at which RBCs sediments in

a period of one hour.

•Also called as Sedimentation Rate or Westergren ESR

•It is a common haematology test.

•It is a non-specific measure of inflammation.

•Also helpful in following progress of some chronic

infections (TB and Osteomylelitis)

•Done in Westergren pipette

Normal ESR

Male: 2-5 mm per hr

Female: 10- 15 mm per hr

Erythrocyte Sedimentation Rate (ESR)

Interpretation of ESR

ESR increased:

Tuberculosis

Osteomyelitis

Rheumatic fever

Myocardial infarction

Rheumatoid arthritis

Chronic lung abscess

Hodgkin's disease

Leukaemia

ESR decreased:

Congestive cardiac failure

Polycythemia

Severe dehydration like cholera

Physiologic condition where

ESR is increased: Pregnancy: After intake of full meal

HEMATOLOGICAL INVESTIGATIONS

(not so frequent in dentistry)

•Prothrombin Time

•Partial Thromboplastin Time

•INR

It is the time in seconds that is required for fibrin threads to

form in citrated or oxalated plasma.

It is used to check the extrinsic pathway factor (F 7) and the

common pathway ( F 5, 10 , prothrombin and fibrinogen).

Normal range: 11 to 15 seconds

Prolonged time indicates abnormal or prolonged Prothrombin

time.

It gets prolonged when plasma level of any factor is below

10% of its normal value

PROTHROMBIN TIME

It is the time in seconds that is required for a clot to form in a

sample of oxalated plasma.

It is used to check the intrinsic system (8, 9, 11, 12) and the

common pathways (5, 10, prothrombin and fibrinogen).

Normal range: 25-35 seconds

If PTT is prolonged it indicates deficiency of factor 8 or 10

PARTIAL THROMBOPLASTIN TIME

INR:

INTERNATIONAL NORMALIZED RATIO

The International Normalised Ratio (INR) is a laboratory

measurement of how long it takes blood to form a clot. It is

used to determine the effects of oral anticoagulants on the

clotting system.

It is the ratio of Patient’s Prothrombin Time to that of normal

Prothrombin time.

INR= Patient`s PT

Normal PT

It should be noted that INR is used to monitor Anti

coagulant therapy & NOT be used as coagulation screening

test

INR values of 5.0 or greater indicate a serious risk of

spontaneous bleeding episodes.

NORMAL RANGE: 0.8-1.2 (No anticoagulant therapy)

02-03 (On anticoagulant therapy)

• Infiltration anesthesia , scaling and root planning

INR <3

• Block anesthesia , minor surgery , extraction

INR <2

• Major surgeryINR <1.5

OTHER BLOOD TESTS

RENAL TEST

Creatinine is a chemical molecule that is present in the

serum of the blood.

It's produced from another molecule, Creatine, which is a

component of muscle.

The amount of Creatinine the body produces each day

depends on the person's muscle mass.

The normal serum Creatinine range for Men= 0.5-1.5 mg/dL.

Women is 0.6-1.2 mg/dL

SIGNIFICANCE:When the kidneys are functioning normally, the amount of

Creatinine in the serum should remain even.

When they're not working properly, the serum Creatinine

level increases.

•Blood Urea Nitrogen (BUN) is another measure of wastes

(urea) in the blood.

•Urea is produced from the breakdown of protein already in

the body and protein in your diet.

The normal BUN level = 7-20 mg/dL in adults and

= 5-18 mg/dL in children.

Blood Urea Nitrogen (BUN)

SIGNIFICANCE:

•A high BUN usually means that kidney function is less than

normal, but other factors may affect the BUN level.

•Sometimes a low BUN may also mean that not enough intake

of protein.

BLOOD GLUCOSE

Normal Blood Sugars Level:

•A normal fasting (no food for eight hours) 70 and 99 mg/dL

•Post Prandial (two hours after eating) upto140 mg/dL

•Random Blood sugar level: 70-140mg/dl

Diabetes is diagnosed by any one of the following:

•Two consecutive fasting blood glucose tests that are equal to or

greater than 126 mg/dL

•Any random blood glucose that is greater than 200 mg/dL

•A 2-hr Oral glucose tolerance test value over 200 mg/dL

Complications of High Blood glucose level include:

•Poor wound healing

•Infection

•Electrolyte imbalance

•Diabetic ketoacidosis

Complications of Low Blood glucose level include:

•Loss of consciousness(syncope)

•Seizure

The most common HIV test, the Enzyme-Linked Immuno

Sorbent Assay, or ELISA (also called EIA), is used to detect

HIV antibodies in a sample of the blood.

HIV TEST

Although HIV tests are very sensitive, they can produce

false-positive results.

So ELISA HIV tests must be confirmed with another HIV

test, such as a Western blot or Indirect

immunofluorescence assay (IFA).

Antibodies won't show up in the blood or body fluid

immediately after infection.

There is a "window period" of six to 12 weeks, and

sometimes several months, before the body starts

producing antibodies to the virus. So even if tested

negative within a few weeks of being exposed to HIV, one

should get tested again at three months and six months.

TEST FOR HEPATITIS B

It is important to identify the type of hepatitis virus causing

infection to prevent its spread and choose the proper treatment

since it is transmitted through infected body fluids.

It also can be transmitted from a pregnant woman to her child

at or near the time of birth.

There are several different HBV tests

• Hepatitis B surface Antigen (HBsAg) - this tests is done

directly for the presence of virus. `

•Hepatitis B core Antibody (HBcAb or anti-HBc)

•Hepatitis B surface Antibody (HBsAb or anti-HBs)

Dental Management of

Bleeding Disorder

Haemostatic agents

LOCAL

Mechanical Thermal Chemical

SYSTEMIC

LOCAL HAEMOSTATIC MEASURES

MECHANICAL METHODS:

•Pressure

•Use of Haemostats

•Suture and Ligations

•Embolization of vessels using steel coils, polyvinyl

alcohol foam, gel foam, silicon spheres, and

methyl methacrylate.

THERMAL METHODS:

•Cautery

•Electrocautery

•Cryosurgery

•Argon beam coagulators

•Lasers

CHEMICAL METHODS:

•Astringent agents: Monsel solution and Tannic acid

•Bone wax

•Thrombin

•Gelfoam

•Oxycel

•Surgicel

•Fibrin glue

•Adrenaline

SYSTEMIC HAEMOSTATIC MEASURES

•Whole Blood

•Platelet rich plasma: one unit can raise the platelet count

by 7000-10,000 cells/cmm of blood

•Fresh frozen plasma: It contain all the coagulation factors.

•Cryoprecipitate: Contain factor VIII, XIII and vWB

•Adrenochrome monosemicarbazon and ethamsylate

90% of inherited haemostatic disorder consist of

Haemophilia A,B and Von Wilibrand’s disease.

MANAGEMENT OF HAEMOPHILIA A and B

PATIENTS:

Replacement therapy :

1. Platelet concentrate

2. Fresh frozen plasma

3. Factor VIII,IX concentrate : Hemophilia A

4. Factor IX concentrate : Hemophilia B

5. Desmopressin

Antifibrinolytic therapy:

1. Epsilon-aminocaproic acid (EACA, Plaslloid)

2. Tranexamic acid (AMCA, Transamin)

MANAGEMENT OF PATIENTS WITH VON

WILLEBRAND DISEASE:

Desmopressin

Replacement therapy

1. Platelet concentrate

2. Fresh frozen plasma

Antifibrinolytic therapy:

1. Epsilon-aminocaproic acid (EACA, Plaslloid)

2. Tranexamic acid (AMCA, Transamin)

CONCLUSION

Reviewing clinical laboratory test results about a patient's condition can provide valuable information for

Diagnosis and management of orofacial conditions

Guidance on assessing the patient's ability to tolerate the proposed dental treatment

A prognosis based on a particular treatment

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2003

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publications. 2003.

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