Page 645 - First Aid for the USMLE Step 1 2020, Thirtieth edition [MedicalBooksVN.com]_Neat
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Renal ` RENAL—PAthoLogy Renal ` RENAL—PAthoLogy SeCTIOn III 601
Acute kidney injury
Prerenal azotemia Intrinsic renal failure Postrenal azotemia
EtioLogy Hypovolemia Tubules and interstitium: Stones
cardiac output Acute tubular necrosis BPH
effective circulating volume (ischemia, sepsis, infection, Neoplasm
(eg, HF, liver failure) nephrotoxins) Congenital anomalies
Acute interstitial nephritis
Glomerulus:
Acute glomerulonephritis
Vascular:
Vasculitis
Malignant hypertension
TTP-HUS
PAthoPhysioLogy RBF GFR In ATN, patchy necrosis Outflow obstruction (bilateral)
reabsorption of Na /H O debris obstructing tubules
+
2
and urea and fluid backflow GFR
In ATN, epithelial/granular
casts
URiNE osmoLALity (mosm/kg) >500 <350 <350
URiNE Na (mEq/L) <20 >40 Varies
+
FE <1% >2% Varies
Na
sERUm bUN/Cr >20 <15 Varies
Acute interstitial Also called tubulointerstitial nephritis. Acute Associated with fever, rash, hematuria, pyuria,
nephritis interstitial renal inflammation. Pyuria and costovertebral angle tenderness, but can be
(classically eosinophils) and azotemia asymptomatic.
occurring after administration of drugs that Remember these 5 P’S:
act as haptens, inducing hypersensitivity Pee (diuretics)
(eg, diuretics, NSAIDs, penicillin derivatives, Pain-free (NSAIDs)
proton pump inhibitors, rifampin, quinolones, Penicillins and cephalosporins
sulfonamides). Less commonly may be 2° to Proton pump inhibitors
other processes such as systemic infections RifamPin
(eg, Mycoplasma) or autoimmune diseases Sulfa drugs
(eg, Sjögren syndrome, SLE, sarcoidosis).
FAS1_2019_14-Renal.indd 601 11/7/19 5:42 PM
