- Most commonly affects children
- Proximal Tubule defect of bicarbonate reabsorption
- Results in bicarbonate wasting
- Initially distal tubule attempts to reabsorb
- Later distal tubule mechanisms overcome
- Medications
- Fanconi's Syndrome
- Medullary cystic disease
- Multiple Myeloma
- Nephrotic Syndrome
- Renal Transplantation
- Failure to Thrive
- Growth retardation
- Vomiting
- Dehydration
- Lethargy
-
Arterial Blood Gas
- Mild to moderate Non-Anion Gap Metabolic Acidosis
- Serum bicarbonate decreased
- Usually not lower than 15 meq/L
-
Urine pH
- Exceeds 5.5 except in severe Metabolic Acidosis
-
Fractional Excretion of Bicarbonate
- FE-HCO3 exceeds 15% if serum bicarbonate >20 meq/L
- FE-HCO3 <5% in Distal RTA
- XRay
- Children: Rickets
- Adults: Osteopenia
- High dose Bicarbonate Supplementation
- Oral Bicarbonate 10-25 meq/kg/day
- Observe for Hypokalemia
- Treat Osteomalacia in adults
- Treat Rickets in children
- Vitamin D Supplementation
- Sodium phosphate 1.6 grams per day