RTA is classified into 4 major forms: distal, proximal, hyperkalemic and combined RTA. Distal RTA is associated with reduced urinary acid secretion, proximal RTA ( pRTA ) is characterized by impaired bicarbonate (HCO3_) reabsorption, hyperkalemic RTA is an acid-base disturbance generated by aldosterone deficiency or resistance and combined RTA is due to carbonic anhydrase II deficiency. Electrolyte and acid-base disturbances are key components of each disorder .