Treatment:
Except in drug induced cases of RTA, the disease is always
persistent and needs permanent treatment.- First treat hypokalaemia and hypocalcaemia.
- Then give sodium bicarbonate to correct acidosis.
After correction of acidosis no need to give potassium
supplementation. - Treatment of infection or obstruction if present.
Proximal RTA
Normally all the filtered bicarbonate is reabsorped unless the
concentration of bicarbonate in the glomerular filtrate is above the
HCO3Tmax which is 25 mmol/L. 80% of reabsorption of HCO 3 occurs in
the proximal tubules through H+ pump. In Proximal RTA, there is a degree
of weakness in H+ pump resulting in a decrease in its HCO 3 reabsorption
capacity and a new steady state is settled in which Tmax of HCO 3 is
decreased (e.g. to 10 mmol/L or 14 mmol/L). All HCO 3 filtered above this
level will be lost in urine (bicarbonaturia) and blood level of HCO 3 will be
decreased.
The HCO 3 reaching the distal nephron will turn the urine alkaline.
This will interfere with ammonium ion and titratable acids excretion and
consequent retention of H+ in the body.
In this phase, the condition is characterized by metabolic acidosis,
hyperchloraemia (excess reabsorption of CL- by PCT on expense of
HCO 3 ), alkaline urine, decrease titratable acids and ammonium ion
excretion.