ANAEMIA

ANAEMIA;

 Classification, Pathogenesis, Pathophysiology

 Objectives

1.      Overview of Haematopoiesis

2.      Anaemia definition

3.      Classification

4.      Pathogenesis of Anaemia

5.      Pathophysiology of Anaemia

6.      Clinical Presentation

7.      Investigation

8.      Treatment

 

HAEMATOPOIESIS

Hemato – Blood Cells

Poiesis: Production

 

ERYTHROPOIESIS

RBCs Maturation

 

ANAEMIA

Reduction in the hemoglobin concentration/red cell mass of the blood below normal range for age and sex

WHO: Adult Male < 13g/dl, Female < 12g/dl,Neonates < 14g/dl, 2yrs to puberty < 11g/dl

Prevalence: 33% of the Global population

Prevalence greater in females than males at all ages

Most frequent in Pre-school Children (under-fives)

 

Pathological Classification of Anaemia…

a)      Inadequate Production

b)      Stem Cells destruction

c)      Inherited – Fanconi Anaemia ( Pancytopenia)

d)     Acquired – Aplastic Anaemia (Pancytopenia), drug induced myelosuppression (eg Chemotherapies/radiotherapy), Chronic Inflammations (ACD), Marrow infiltration (Leukaemias, Lymphoma, Metastasis)

e)      Nutritional

f)       Dietary Deficiency: Fe, F.A, Vit B 12

g)      Malabsorption: Gastrectomy, Lack of Intrinsic Factor (Pernicious)

h)      Increased demands: Pregnancy, Growth Period

i)        Decreased/Absent Erythropoietin: CKD A 3 yr old with FA

j)        Blood Loss

k)      Acute: Trauma etc

l)        Chronic: Eg. GI losses - PUD, Intestinal parasites, colon Ca

m)    Increased Destruction (Intravascular/Extravascular)

n)      Inherited: Hemoglobinopathies, enzymopathies, membrane defects

o)      Acquired: Infections, drugs, immune mediated, hypersplenism (Pancytopenia), Mismatched transfusions

 

Normal RBC Morphology

Morphological Classification Of Anaemia

Pathophysiology of Anaemia

Tissue Oxygen Delivery

Oxygen Tissue Consumption

 

 

 

Clinical Presentation

Depends on:

a)      Speed of Onset

b)      Rapidly progressive causes more symptoms than slow onset

c)      Severity Above 9g/dl, there may be no symptoms

d)     Age

e)      Cardiovascular compensation impaired

 

Symptoms of Anaemia

a)      Easy fatigue and body weakness

b)      Shortness of Breath esp on Exertion

c)      Increased awareness of Heart beats

d)     Headaches/dizziness/fainting

e)      Fluid congestion if Heart failure has developed

f)       Other depending on the cause such as PICA in Iron def

 

Signs of Anemia

a)      Pallor of mucous membrane and nail beds

b)      Hyperdynamic circulation with tachycardia, bounding pulse, Apex beat shift if cardiomegaly present, systolic flow murmur

c)      Low blood pressure

d)     Signs of failure may be present-bilateral LL edema, Elevated JVP, Congested tender liver, Bilateral fine crackles at lung bases

 

Investigations of a Patient with Anaemia

 Anaemia is NOT A DIAGNOSIS, it is a manifestation of an underlying pathology

a)      Full Blood Picture – Automated Counts + Peripheral Film

b)      Reticulocyte count

c)      Iron Studies:

d)     Serum Fe

e)      Serum Ferritin

f)       Transferrin Saturation

g)      TIBC

h)      Serum Vitamin B12

i)        Serum Folate

j)        Bone Marrow Aspiration/Trephine Biopsy

k)      Markers  of Hemolysis

l)        LDH

m)    Bilirubin – Total and Direct (Increased Indirect reflects Hemolysis)

n)      Serum Haptoglobulin

o)      DAT (Coombs Test)

p)      Hemoglobinuria

q)      Assessment of GI Bleeding – Stool for Occult blood, OGD, Colonoscopy

r)       Renal Function -  Serum Creatine, BUN

s)       Liver Function & Enzymes – PT,PTT, INR, AST & ALT

 

 

 

Management

Find the cause and Treat

 

Supportive:

Depending on Severity of Anaemia – Blood Transfusion may be required and Life Saving

Severe < 7g/dl

Very Severe </= 4g/dl Fe, F.A, Vit B 12