DR Medhat MRCP

- Reabsorption of HCO3 - (85% in PCT & 15% IN DCT) & hence regeneration of
blood HCO3 (Alkali reserve).
3) Role of the liver
o Transform ammonia (NH3 + ) into urea (natural substance).
o Transform lactic acid into glycogen.
o Conjunction & detoxification of many substances.
H + α
PH = Log
Metabolic Acidosis
o Is decrease blood PH < 7.35 due to decrease blood bicarbonate level .
o commonly classified according to the anion gap (i.e difference between
unmeasured anions (-ve charged ions) & unmeasured cations (+ve charged ions).
o Normally blood is electromechanically neutral i.e anions = cations
Measured
Unmeasured
Total
ANIONS (mmol/L)
Bicarbonate (24)
Chloride (104)
Proteins (15)
Phosphate (2)
Sulphate (1)
Organic acids (5)
CATIONS (mmol/L)
Sodium (140)
Potassium (4.5)
(Anion gap)
Calcium (5)
Magnesium (1.5)
(151) (151)
Unmeasured anions + measured anions = unmeasured cations + measured cations
So, Unmeasured anions - unmeasured cations = measured cations - measured anions
i.e (Anion gap) = measured cations - measured anions
=(Na + + K + ) - (Cl - + HCO - 3).
Since K + is numerically low, so it can be neglected in the equation :
(Anion gap) = Na + - [HCO3 - + Cl - ]. Normally = 10-18 mmol/L.
o NB: If a question supplies the chloride level then this is often a clue that the
anion gap should be calculated.
85