Specimen Name Result Units Range
Plasma Sodium 141 mmol/L (135-145)
Potassium 1.7 mmol/L (3.5-5.5)
Chloride 111 mmol/L (100-109)
Bicarbonate 15 mmol/L (22-32)
Anion Gap 17 mmol/L (7-17)
Glucose 12.5 mmol/L (3.8-5.5)
Urea 7.7 mmol/L (2.7-7.2)
Creatinine 120 μmol/L (60-110)
Osmolality 284 mmol/kg (275-295)
Urine Sodium 38 mmol/L (> 20)
Chloride 27 mmol/L
Potassium 27 mmol/L
pH 7.28 (4.4-8.0)

58yo RAH patient.
Renal Tubular Acidosis

Type I - Distal or "Classic":

  • autosomal dominant (+ variable penetrance)
  • usually presents in childhood
  • inability to acidify urine
  • H+ retained with Cl-
  • hyperchloraemic-hypokalaemic acidosis

Diagnosis:

  • low AG / hyperchloraemic metabolic acidosis
  • urine pH > 5.4 following an acid load (100mg/kg NH4Cl)
  • absence of urinary infection
  • hyperchloraemia / hypokalaemia

Management:

  • NaHCO3 ≈ 0.5-2.0 mg/kg/day
  • K+-supplement : usually not large
  • can use Na/K-citrate

Complications:

  • ↑Ca++ excretion : 2° hyperparathyroidism, nephrocalcinosis, renal stones
  • Vit-D deficiency : osteomalacia, ricketts

 

Renal Tubular Acidosis

Type 1 Type 2 Type 4
Location DT & CT
α-intercalated cells		 PT Adrenal
Acidaemia Yes → Severe Yes ≈ mild Mild
Potassium Hypokalaemia Hypokalaemia Hyperkalaemia
Pathology Failure of
H+↔K+ exchange		 Failure of
HCO3- reabsorption		 ↓ Aldosterone
(hypo-/pseudo-)
Indicence Congenital (AD)
50:million		 Congenital (AD)
Acquired*
NB : *type 2
  • acquired most common → recovery phase ATN!
  • AutoD : deToni-Fanconi-Debris synd → aminoaciduria / phosphaturia