Specimen Name Result Units Range
Plasma Sodium 137 mmol/L (135-145)
Potassium 1.7 mmol/L (3.5-5.5)
Chloride 120 mmol/L (100-109)
Bicarbonate 8 mmol/L (22-32)
Anion Gap 11 mmol/L (7-17)
Glucose 4.5 mmol/L (3.8-5.5)
Urea 8.4 mmol/L (2.7-7.2)
Creatinine 180 μmol/L (60-110)
Urine Sodium 43 mmol/L (> 20)
Chloride 92 mmol/L
pH 7.00 (4.4-8.0)

Young child with failure to thrive.

Chronic weakness - worse recently.
Renal Tubular Acidosis - Type 1
  • profound hypokalaemia → weakness
  • HCO3- : metabolic acidosis + normal AG
  • moderate AKI - especially for a child
  • failure to acidify urine → RTA

Complications:

 

Hyperchloraemia:

  1. any hypernatraemic state
  2. respiratory alkalosis
  3. normal AG metabolic acidosis:
    • renal - RTA, CA inhibitors, early uraemia
    • non-renal - hypoadrenalism, diarrhoea, ureterosigmoidoscopy, treated DKA

 

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!
  • Auto-D variant: deToni-Fanconi-Debris syndrome
    → aminoaciduria & phosphaturia