Blood Values and Indices Dr Mohammed Jeelani Specific

Blood Values and Indices Dr Mohammed Jeelani

Specific learning outcomes �List types of hemoglobin and its normal values �Describe functions and clinical significance of hemoglobin �List the different types of WBCs �Give the normal value of each type of WBCs and its clinical significance �Describe the normal value of platelets and its clinical significance �Describe the normal values and indices of RBCs and their clinical significance

Types of haemoglobin �Adult haemoglobin or haemoglobin A ◦ Haemoglobin A [Hb. A (α 2β 2)]. ◦ Haemoglobin A 2 [Hb. A 2 (α 2δ 2)]. - 2. 5% of Hb. A �Fetal haemoglobin or haemoglobin F [Hb. F (α 2γ 2)]

Functions of Haemoglobin �Transport of O 2 from lungs to tissues �Transport of CO 2 from the tissues to the lungs �Control p. H of the blood: six times the buffering capacity as compared to the

WHITE BLOOD CELLS

Leucocytosis increase in total WBC count above 11, 000/μL. Physiological causes 1. Exercise, 2. After food intake, 3. Mental stress, 4. Pregnancy and 5. Exposure to low temperature. Pathological causes 1. Acute bacterial infections especially by the pyogenic organisms, 2. Acute haemorrhage, 3. Burns, 4. Post-operative period, 5. Tuberculosis and 6. Glandular fever.

Leucopenia decrease below 4000/μL. 1. Infections by the non-pyogenic bacteria, especially typhoid fever and paratyphoid fever. 2. Viral infections, such as influenza, smallpox, mumps, etc. 3. Protozoal infections. 4. Starvation and malnutrition. 5. Aplasia of bone marrow. 6. Bone marrow depression due to: � Drugs, such as chloromycetin and cytotoxic drugs � Repeated exposure to X-rays or radiations. � Chemical poisons like arsenic, dinitrophenol and antimony.

Platelets �Normal count: 150, 000 to 450, 000/μL with an average of 2. 5 lac/μL.

Thrombocytosis. increase in the number of platelets more than 4. 5 lac/μL 1. After splenectomy 2. After: � Haemorrhage, � Severe injury, � Major surgical operation and � Parturition. 3. In myeloproliferative disorders such as: � Chronic myeloid leukaemia, � Polycythaemia vera and � Myelofibrosis.

Thrombocytopenia. Decrease in the number of platelets below 1. 5 lac/μL 1. Idiopathic thrombocytopenic purpura 2. Bone marrow depression 3. Acute leukaemia or secondary deposits of malignancy in the bone marrow. 4. In infections like smallpox, chickenpox, typhoid and dengue fever. 5. In hypersplenism. 6. In toxaemia, septicaemia and uraemia.

Red cell indices �Used for diagnosis of Type of anaemia �Include �Mean corpuscular volume �Mean cell haemoglobin concentration �Colour index

Mean corpuscular volume (MCV): �average �Normal volume of a single RBC value of the MCV is 90 μm 3 (range 78– 94 μm 3) �Decreased value of the MCV occurs in microcytosis. �Increased value of the MCV occurs in macrocytosis

Mean cell haemoglobin (MCH) �average weight of the Hb contained in each RBC �Normal 33) pg. value of MCH is 30 (range 27–

Mean cell haemoglobin concentration (MCHC) �amount of Hb expressed as a percentage of the volume of a RBC. �Normal value of MCHC is 33. 3% (range 30– 38%). �In hypochromic RBCs the values of MCHC are less than the normal, as is seen in the iron deficiency anaemia. � Hyperchromic : rare (RBCs cannot hold Hb beyond the saturation point).

Colour index (CI) �ratio of Hb to RBC. �For calculating CI, Hb of 14. 8 g/d. L is taken as 100% and RBC count of 5 million/μL is taken as 100%. �Normal values of CI vary from 0. 85 to 1. 15. �CI is insignificant because normal range of RBC is very wide.

Reference �Medical physiology for UG, Indu khurana, 1 st edition, Elsevier publication chapter 3. 2 page 101 -102, 109 -111, chapter 3. 3 page 121 -122, chapter 3. 5 page 150 -151

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