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Type 1 Renal Tubular Acidosis

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Type 1 Renal Tubular Acidosis, Type I Renal Tubular Acidosis, Type I RTA, Distal RTA, Distal Renal Tubular Acidosis, Classic RTA

  • See Also
  1. Renal Tubular Acidosis
  • Pathophysiology
  1. Distal Tubule fails to excrete ammonium
  • Causes
  1. Autosomal Dominant inherited disorder
  2. Acquired causes
    1. Systemic Lupus Erythematosus
    2. Sickle Cell Anemia
    3. Nephrocalcinosis related disorders
      1. Hyperparathyroidism
      2. Medullary sponge Kidney
    4. Medications and Toxins
      1. Amphotericin B
      2. Lithium
      3. Toluene
  • Signs
  1. Musculoskeletal weakness
  2. Recurrent Nephrolithiasis
  • Labs
  1. Arterial Blood Gas (ABG)
    1. Non-Anion Gap Metabolic Acidosis
  2. Urine pH
    1. Elevated >5.5 despite Metabolic Acidosis
  3. Serum Potassium
    1. Low or normal
  4. Fractional Excretion of Bicarbonate
    1. FE-HCO3 <5%: Distal RTA
    2. FE-HCO3 >15%: Proximal RTA
      1. Assumes serum bicarbonate >20 meq/L
  1. Dose: 1-2 meq/kg/day
  2. Goal: Serum bicarbonate > 22 meq/L
  3. Corrects Hypokalemia