Sunday, May 13, 2012

Renal tubular acidosis

 common USMLE topic

Non anion gap metabolic acidosis

Type 1:
Distal RTA
Failure of H+ secretion by the α intercalated cells of distal tubes
There's hypokalaemia
Met. acidosis is severe, more alkaline urine >5.3
May be associated with urolithiasis , rickets

Type 2:
Proximal RTA.
e.g Fanconi syndrome (prox tubular cell dysfunction)
Failure of  HCO3 reabsorption from the urine by the proximal tubular cells
There's hypokalaemia. Also associated with rickets
Met acidosis is less severe because distal tubular function is normal. urine PH<5.3

Type 4:
No aldosterone (Addisson's disease,ACEIs,ARBs,DM nephropathy,Sickle cell nephropathy)
Na/K pump not responding to aldosterone (NSAID nephropathy,CKD,)
There's hyperkalaemia, hyponatremia, hyperchloraemia
urine PH<5.3. . Met. acidosis is mild

1 comment:

  1. this is a great little summary, to the point! thanx for this :)