Anemia is a reduced level of circulating hemoglobin. It can be classified based on red blood cell size and color. Common causes of anemia include iron deficiency, blood loss, vitamin deficiencies, and chronic diseases. Surgical patients are often anemic due to blood loss or chronic illness. Investigating anemia involves considering potential causes through history, physical exam, blood tests, and imaging. Management depends on severity and cause but may include iron supplementation, vitamin replacement, treating underlying conditions, or blood transfusions in severe or emergency cases. Transfusion requirements differ for anemic versus acutely bleeding patients.
3. Introduction
Anemia is defined as a reduced level of circulating Hb
Composition
Total blood volume – 5.5 litres
Divided into Plasma & cells
Three main types of cells
Erythrocytes
Hematocrit
Leukocytes
Thrombocytes
4. Plasma
A protein-rich solution
Carries the blood cells
Transports nutrients, metabolites, antibodies
and other molecules between organs.
5. All blood cells originate from pluripotentstem
cells in the bone marrow.
Divide lymphoid stem cells and myeloid stem
cells
6.
7. Erythrocytes
Transport oxygen via haemoglobin
Biconcave disc shape
Contain no nucleus or organelles
Reticulocytes (immature erythrocytes) contain residual RNA
Average lifespan is 120 days
Broken down by macrophages within the spleen, liver
and bone marrow
Synthesis stimulated by erythropoietin
8. Leucocytes
Neutrophils
Most abundant leucocyte (40–70%)
Spend 14 days in the bone marrow but have
a half-life of only 7 hours in the
blood
Lymphocytes
Second most common leucocyte (20–50%)
Important for specific immune response
9. Monocytes
These account for 15% of leucocytes
Largest leucocyte, mobile phagocytic cell Important in
inflammatory reactions.
Eosinophils
Make up 5% of leucocytes
Important defence against parasitic infections
Basophils
Thrombocytes
10.
11. Anaemia
Anaemia is the reduction in the
concentration of circulating haemoglobin
below the expected range for age and sex:
Adult male: <13 g/dl
Adult female: <11.5g/dl
12. Acute or Chronic
Causes
Decreased production
Increased loss
20. Clinical effectsof anaemia
A slowly falling haemoglobin level allow for tissue acclimatisation –
Palpitations, angina, ear buzzing
Tachycardia
Asthenia, Lethargy, fatigue
Increased cardiacoutput
Reticulocytosis
Can anemia be beneficial? Increased blood flow across capillaries:
critical illness
21. Surgical haematology
Changes in haematology as a response to major surgery
Leucocytosis (usually due to increase in neutrophil count
relative to lymphocytes)
Relative anaemia:
Chronic illness
Blood loss
Impaired erythropoiesis
Decreased serum iron
Relative thrombocytosis
Increased acute phase reactants includingerythrocyte
sedimentation rate (ESR) and C-reactive protein (CRP)
22. Investigating anaemia
History
Acute or chronic blood loss (e.g menorrhagia, per
rectal bleeding or change in bowel habit)
Insufficient dietary intake of iron and folate (e.g elderly
people, poverty, anorexia, alcohol problems)
Excessive utilisation of importantfactors (e.g pregnancy,
prematurity)
Malignancy Chronic disorders(e.g malabsorption states affecting
the small bowel)
Drugs (e.g phenytoin, antagonises folate)
24. Investigating anaemia
Folate levels – Red cell folate levels > Serum folate
Iron studies
Vitamin C & iron
Investigate for causes of blood loss
Upper & Lower GI endoscopy
IVU, Cystoscopy
25. Management
Emergency Surgery
Transfusion
Elective surgery – Reversible causes should be corrected
Mildly anemic – may tolerate GA and sedation
Profound Anemia – Transfusion & Iron supplementation
ACD does not respond to hematinics; requires blood
transfusion
26. Blood transfusion requirements for the anemic
patient are very different from those of the patient
with acute blood loss.
During transfusion – caution with circulatory overload
and CCF
Red cell concerntrates should be <14 days as these
have near normal levels of 2,3DPG
28. Conclusion
Blood – is composed of Plasma and cells
All blood cells originate from a hematopoietic stem cell.
Major surgery can result in hematologic changes
Anemia is not a diagnosis – Must be classified, investigated and
treated appropraitely
Anemia can be beneficial in critical illness
Transfusion methods differ per patient and red cell concentrates <14
days are preferred