Renal Flashcards
A protein to creatinine ratio (PCR) of 1 is equivalent to?
1 g of protein on a 24 hour urine
Most accurate test to determine protein excretion
Eosinophils on UA think?
Allergic or acute interstitial nephritis (AIN)
UA with false positive for blood? What will you see on microscopic exam?
Due to hemoglobin or myoglobin, but no RBCs on microscopic exam of urine
Urinary sodium and FENa prerenal azotemia
Both LOW
UNa: less than 20
FENa less than 1%
Decreased BP or intravascular volume will increase Aldo, which increases sodium reabsorption so it is low in urine
However more water is reabsorbed due to ADH, so urine is actually concentrated
Urine osmolality and sodium excretion in ATN
UNa above 20 – Wastes sodium
UOsm below 300– Inappropriately low (should be above 500) cannot concentrate
Inability to reabsorb sodium and water
Manifestation of sickle cell trait
Isosthenuria: defect in renal concentrating ability, will produce inappropriately dilute, high volume of urine despite dehydration
Causes of ATN and timing
Aminoglycosides, ampohotericin, nsaids, cisplatin, cyclosporine, Acyclovir
contrast media, prolonged ischemia, hemoglobin and myoglobin – rhabdo
Tumor lysis syndrome, ethylene glycol poisoning, Ben’s Jones proteins
Contrast has a very rapid onset, creatinine may rise the next day
Other toxins need 5 to 10 days
What else is use besides IV hydration to prevent contrast induced nephrotoxicity, with little evidence to support their use
N – acetylcysteine, bicarbonate
Causes of renal papillary necrosis
SAAD papa Sickle cell disease Analgesics- NSAIDs Acute pyelo Diabetes
Electrolyte changes in rhabdo
Hyperkalemia, hyperuricemia, Hyperphosphatemia due to release from cells
LOW calcium as more calcium binds to damaged muscles
In contrast, hemolysis does not cause hyperuricemia because RBCs do not have nuclei butt muscle cells do
How to treat rhabdo
IV hydration, mannitol – osmotic diuretic, bicarb – drives potassium back into cells and may prevent myoglobin precipitation in the kidney tubules
What specific findings with cholesterol emboli
Eosinophilia/uria, elevated ESR, Low complement, preferable pulses are normal as they’re too small to accrued large arteries
Drugs implicated in AIN
Penicillin, cephalosporin, sulfas (Lasix, thiazides), phenytoin, rifampin, quinolones, allopurinol, PPIs
These meds also cause drug allergy, rash, SJS, TEN, hemolysis (skin, kidney, RBCs)
Also SLE, sarcoidosis, infections
Diagnosis of papillary necrosis
UA shows RBCs and wbc’s, may show necrotic kidney tissue
Best test: CT scan, shows abnormal internal structure of kidney from loss of the papilla
Abdominal pain, stroke or MI in a young person, digital gangrene
Elevated ESR and CRP
Polyarteritis nodosa
Systemic vasculitis of small and medium arteries that most commonly affects the kidneys, may affect virtually every organ except the lung, associated with hepatitis B
