Renal Tübüler Asidoz (RTA)

 

Renal Tübüler Asidoz (RTA)

Distal (Tip 1 ) RTA :

– For adult patients with a serum bicarbonate <16 mEq/L, a reasonable starting dose is 30 mEq of bicarbonate or citrate (which is a bicarbonate precursor) four times daily (120 mEq total per day). If the initial serum bicarbonate is >16 mEq/L, a reasonable starting dose is 40 mEq of bicarbonate or citrate twice daily (80 mEq total per day). There are multiple options for attaining this dose of alkali therapy .

The serum bicarbonate should be measured at approximately one week. The dose can then be titrated up or down depending upon the initial response, rechecking the bicarbonate at weekly intervals until a maintenance dose is attained (with a goal serum bicarbonate concentration of 22 to 24 mEq/L). This maintenance dose of bicarbonate (or citrate) is generally between 30 and 50 mEq twice daily.

Proksimal (Tip 2) RTA :

Management

Patients with Fanconi syndrome — Treatment of the metabolic acidosis is more difficult in proximal RTA than in distal RTA because raising the serum bicarbonate concentration will increase the filtered bicarbonate load above the proximal tubule's reduced reabsorptive capacity, resulting in a marked bicarbonate diuresis. Thus, in contrast to the 1 to 2 mEq/kg per day of alkali therapy required for treatment of distal RTA, alkali doses in proximal RTA are higher. The amount of bicarbonate required will vary in different patients depending upon the extent to which the reclamation process is impaired. As in patients with distal RTA, the goal of therapy is to achieve a normal serum bicarbonate concentration (22 to 24 mEq/L), but this goal is often unattainable. In such cases, raising the serum bicarbonate to as near to normal as possible should be the goal.

We initially prescribe 10 to 15 mEq/kg per day of alkali, given in divided doses, in patients with proximal RTA to overcome urinary bicarbonate losses and raise serum levels

The treatment goal is to achieve and maintain a normal serum bicarbonate level (ie, 22 to 24 mEq/L).