55 yo man with SC disease and membranous nephritis. He is taking an ACE inhibitor to decrease his urine protein and delay progression of renal disease. We saw these labs
| Electrolyte panel | |||||
|---|---|---|---|---|---|
| Na | 133 | Cl | 107 | BUN | 27 |
| K | 5.1 | HCO3 | 19 | creat | 1.2 |
This was the last day of my tour at the VA. So instead of making this a puzzle, I will tell you what we did. You can consider your options before you read what follows:
Serum osms 283
Urine osms 351
Urine Na 101
Urine K 13
Urine Cl- 96
We did not obtain an ABG because we felt the diagnosis was crystal clear.
TTKG was low at 2.1 confirming low aldosterone effect
Urine anion gap was positive +18 confirming renal acidosis
ACTH stim test was normal
So we made a diagnosis of type IV RTA. We consulted renal, and they decided to withhold the ACE inhibitor for 2 weeks, checking a urine protein/creatinine now and then. They will reassess this complex problem at that time, i.e., the patient needs and ACE-I to decrease proteinuria, but the ACE-I induces a type IV RTA.
I hope my nephrology readers will provide a commentary on how they would handle this problem.
{ 4 comments… read them below or add one }
People with sickle cell disease can get tubular hyperkalemia even without an ACE-I. This being said, I personally would not consider a K of 5.1 a good enough reason to stop the ACE-I. I would put the patient on oral sodium bicarbonate tablets or Shohl's solution, and add furosemide or torsemide if necessary, in order to keep the ACE-I.
I think the need for decreasing proteinuria with ACEi trumps the mild hyperkalemia and acidosis from IV RTA. Never seen someone die from that.
The Potassium is within normal range and the sodium and bicarb are very minimally down.
Why do anything other than continue meds?
The labs don't seem worrisome. You have clear evidence ACE-I prevents progression of renal disease in proteinuric states, his acidosis is minimal, and there seem to be no clinical problem with his electrolyte abnormality. Membanous nephropathy can lead to dialysis with close to 20% mortality in the first year; type IV RTA almost never leads to severe life threatening acidosis or severe hyperkalemia leading to dysrhythmia.. Are you treating the patient, or treating yourself?