Haematology Watch


Absolute leukocyte count = Differential Leukocyte Count % x TLC

Body Surface Area (Mosteller formula) in square metre = under root (height in cm x weight in kg / 3600)

Corrected Calcium = S. Calcium mg/dL + [0.8 x (Normal Albumin - Patient's Albumin)]

in other words, each 1 g/dL decrease of albumin will decrease 0.8 mg/dL in measured serum Ca and thus 0.8 must be added to the measured Calcium to get a corrected Calcium value.

Calcium in mg/dL = 4 x Calcium in mmol/L

Corrected Creatinine Clearance = (Urinary creatinine/Plasma creatinine x Volume of urine in mL per minute) x (1.73/Body Surface Area)

Corrected reticulocytes count or Reticulocytes Index = (Patient's Hct/Normal Hct) x Reticulocyte % 

Corrected TLC = [100 / (100+NRBC)] x TLC

Fall in Serum Ferritin per venesectio= 25 ng/mL

Iron requirement = (repletion of iron stores) + (repletion of circulating iron)

                            = (1000 mg) + (weight in kg x Desired increment in Hb in g/dL x 2.2)

Malarial Parasite Index (Thin film) = Number of Trophozoites & Schizonts in 1000 RBCs / 10

One drop of blood = 50 uL

Platelet count (in 10^3/uL)= 

     Indirect Method 1 (more accurate)=(Number of platelets per 1000 RBC) x TRBC x 1000

     Indirect Method 2 (more easy)=(Number of platelets in a field having 50% red cells in triplets using x100 lens) x 10 fields x 1000

rpm = under root [ (g x 105) / (1.118 x radius of rotor) ]

Red cell replacement in children 

     = Desired increment in Hb in g/dL x Weight in kg x 3/Hct of the blood bag

Stem cell dose = Absolute mononuclear cells in peripheral blood x Amount of harvest in mL / recipient's weight in kg

Total leukocyte count = [Average number of WBC in 10 fields using x40 objective in morphology area] x 3