Nephrology Flashcards
Poststreptococcal glomerulonephritis
Subepithelial IgG immune complex depositions
MC in children
1-3 weeks after strep infection
Findings: HTN Edema Brown urine - tea color, cola color high ASO titer Anti-DNAse B
EM: subepithelial “humps”, hypercellular glomeruli
Tx: supportive, self limited
"PHARAOH" Proteinuria hematuria Azotemia RBC casts Anti Strep/Anti DNAseB Oliguria Htn
Lupus nepritis
Mesangial
Membranous
Focal nephritis
Diffuse nephritis - MC and worse
SLE -> variable changes
-Immune deposits, proliferation of mesangial cells, thickening of GBM
Findings: Proteinuria ANA Anti-DNA Ab LM - endothelial deposits cause "wire loops"
Tx: glucocorticoids ACE-I statin Immunosuppressant - cyclophosphamide or mycophenolate mofetil
Granulomatosis with polyangiitis (Wegener’s)
Granulomatous vasculitis - kidneys, lungs, upper airwas
Findings: Microscopic hematuria Pulmonary nodules/infiltrates Saddle nose, sinus disease, pallet granuloma/ ulcers c-ANCA
Tx:
glucocorticoids
cyclophophamide
Goodpasture’s syndrome
IgG antibodies against the glomerular basement membrane
Findings: Proteinuria and hematuria Cough/hemoptysis Pulmonary infiltrates IF: linear deposits
Tx:
Plasmapheresis
Glucocorticoids
IgA nephropathy (Berger dz)
IgA immune complexes in the mesangium
Mesangial proliferation
Findings:
URI/tonsillitis
children with Henoch-Schonlein purpura
EM/IF: mesangial deposits - dark/dense
Tx:
ACE-I
Glucocorticoids
cyclophosphamide
Alport syndrome
X linked - type IV collagen synthesis
Defective basement membranes - splitting BM
Findings:
Cataracts
Nephritis
High frequency hearing loss
Tx:
Ace I
renal transplant
Pauci-immune rapidly progressive glomerulonephritis (RPGN)
Cresent-shaped fibrin deposits int he glomeruli
Scarce immune complex deposits
Findings:
microscopic hematuria
proteinuria
p-ANCA
Tx:
rapid progression to ESRD - weeks to months
Glucocorticoid
Cyclophosphamide
Nephrotic syndrome
proteinuria >3.5 g/24 hrs
hypoalbuminemia less than 3
peripheral edema
Hypercoagulability hld htn Ascites foamy urine
Minimal change disease
Effacement of podocyte foot processes
MC children
Findings: proteinuria hypoalbuminemia edema - periorbital, sacral, scrotal HTN
Tx: glucocorticoids
Focal segmental glomerular sclerosis
Sclerosis is focal - less than half of glomeruli, darker pink
Segmental - only part of each glomerulus
MC cause of nephrotic sn in adults
higher in AA, latinos, HIV
Tx: glucocorticoids ACE-I Statin \+/- cyclosporine
Membranous nephropathy
Thickinging of BM
Spike and dome
Idiopathic or secondary to SLE or Hep B
Proteinuria MC than hematuria
Tx:
ACE-I
statin
+/- Cyclophosphamide + steroid
Membranoproliferative glomerulonephritis
train track appearance
Subendothelial humps of IgG along GBM -> formation of second GBM
Mesangial cells proliferate between GBMs
Mesangial immune deposits
Assoc with:
SLE
Subacute bacterial endocarditis
Hep C
Tx:
underlying cause
glucocorticoids
+/- cyclophosphamide
Diabetic nephropathy
Thickening of the GBM
Kimmelstiel-Wilson nodules - aceullular eosinophilic nodules in the mesangium
Expansion of the mesangium
proteinuria more common than hematuria
Tx:
Aggressive glycemic control
Aggressive BP control
ACE-I or ARB
Renal Amyloidosis
Abnormal amyloid proteins deposit in tissues - kidney, heart, liver, muscles, brain
Expansion of mesangial matrix
Congo red stain: amyloid proteins apple-green birefringence
May be due to: Plasma cell dyscrasia (Ig light chains) Chronic inflammatory diseases - RA, spondyloarthropathy, IBD hemodialysis heritabile amyloidosis
Tx:
mephalan - suppress BM
Hematopoietic cell transplant
Hyaline casts
Concentrated urine - low flow urine, diuretics, dehydrated
RBC casts
Glomerular bleeding - nephritis, vasculitis
WBC casts
Tubular interstitial disease, acute pyelo, other glomerular dz
Epithelial cells casts
ATN, acute interstitial nephritis, glomerulonephritis
Granular casts
ATN (MC)
Muddy brown casts
Acute interstitial nephritis
Causes:
MC - drugs: B-lactams, sulfonamides, aminoglycosides, NSAIDs, allopurinol, PPIs, diuretics
Infections - strep, TB, EBV, CMV, E. coli, candida
Autoimmune: SLE, sarcoidosis, Sjogren
Presentation: Rash Fever Elevated creatinine Eosinophilia - serum and urine
Dx: renal bx
Tx: stop offending agent
Refractory - corticosteroids
Hydrate, supportive
Complications: acute tubular necrosis, ESRD
Pyelonephritis
Organisms:
E. coli, S. saprophyticus, klebsiella, Proteus
Candida - immunocompromised
Risk: Urinary obstruction BPH Cancer Previous pyelonephritis Diabetes Indwelling catheter Pregnancy
Presentation: Suprapubic/ flank pain Fever/ chills N/V Urinary frequency, dysuria, and urgency
Labs:
Elevated WBCs
WBC casts
positive urine cx >100000 bacteria
CT/US to r/o obstruction
Tx: Inpatient - empiric antibiotics IV Ceftriaxone Cefepime Levofloxacin Ciprofloxacin astreanam
Polycystic kidney disease
AR - kids, early death w/o transplant
AD - adults, MC
Presentation: Asx until advanced Flank pain Chronic UTIs Gross hematuria Palpable kidneys Hypertension
Labs:
elevated BUN, Cr
Anemia - low epo
Hematuria, proteinuria
US and CT - large multicystic kidneys
Tx:
ACE/ARB to control htn
statins
vasopressin receptor antagonists (tolvaptan) to decrease cAMP and decrease cysts
Complications: ESRD Hepatic cysts Intracranial aneurysms MVP AR
Renal cell carcinoma
MC primary malignant neoplasm of renal parenchyma
Risk factors:
Smoking
Exposure to cadmium and asbestos
Increase stage
Presentation: Flank pain Weight-loss Abdominal/ flank mass Hypertension Fever Hematuria Scrotal varicocele
Labs:
Renal failure
Polycythemia - elevated epo activity
Dx:
Biopsy not necessary - risk seeding peritoneum
Imaging adequate
Tx:
Nephrectomy or renal sparing resection with LN dissection
Immunotherapy
Radiation, chemo
Poor prognosis if not caught early
Acute kidney injury criteria
Abrupt increase in creatinine >0.3 in 48 hrs
>50% increase in Cr
Oliguria of less than 0.5 ml/kg/hr for more than 6 hrs
Causes of acute kidney injury
Prerenal: Hypovolemia - acute hemorrhage Systolic heart failure NSAIDs Septic shock
Intrarenal:
Glomerular disease
Acute tubular necrosis
Poly cystic kidney disease
Postrenal:
Prostate disease
Metastatic cancer
obstruction
Presentation of acute kidney injury
Elevated creatinine Edema Hypertension Low urine output Fatigue Anorexia Vomiting Altered mental status Seizures
Fractional excretion of sodium
FEna = (Una/SerumNa)/(Ucr/Serumcr)
Less than 1%: prerenal - retaining sodium and fluid
> 2% intrinsic renal disease - post renal
Chronic kidney disease
MC causes: htn, DM
Presentation:
Fluid overload: hypertension, edema
Uremia: encephalopathy
Decreased epo: anemia
Labs:
Elevated creatinine, potassium, phosphate
Decreased sodium
Vit D deficiency
Increased urine Micro albumin (DM, HTN) - early sign, start ACE/ARB
Tx: Stop smoking Aggressive BP control -loop diuretic, ACE/ARB -b-blockers reduce CAD risk -Nifedipine, amlodipine - risk LE edema
DM: aggressive control - avoid metformin Aggressive lipid control - Statins Iron and Epo Vit D replacement Phosphate binders - Phos-lo Daily ASA 81 mg - reduce endothelial injury and CAD risk
Indications for dialysis
Severe hyperkalemia Severe metabolic acidosis Fluid overload Uremic syndrome CKD - Cr over 12, BUN over 100 Severe overdose or toxic exposure
Staging of chronic kidney disease
by 30s
Stage 1 - GFR over 90 Stage 2 GFR 60-89 Stage 3 a GFR 45-59 Stage 3b GFR 30-44 Stage 4 GFR 15-29 Stage 5 GFR less than 15
DDx for hypovolemic hyponatremia
Urine sodium less than 10 - extra renal losses
- GI losses - V/D, NG tube
- Fluid sequestration - peritonitis, pancreatitis
- Insensible loses - sweating, extensive burns
Urine sodium greater than 20 - renal losses
Diuretics - thiazides
Salt losing renal disease
Partial urinary tract obstruction
Adrenal insufficiency - inadequate mineralocorticoid, Addison
DDX for hypervolemic hyponatremia
Urine sodium less than 10 -
CHF
Cirrhosis
Nephrotic syndrome
Urine sodium over 10
Renal failure
SIADH
Causes:
CNS disease - Head trauma, brain tumor, stroke, CNS infection, pituitary surgery
Pulmonary disease - pneumonia, tumors - small cell
Drugs: NSAIDs, antidepressants, antipsychotics, antineoplastic agents, carbamazepine, ecstasy, vasopressin, DDAVP
Other: HIV/AIDS, major domino or thoracic surgery
Labs: Hyponatremia Low serum osmolality High urine osmolality Urine sodium > 20
Pseudohyponatremia
Serum volume is expanded by substance -lipid or protein (multiple myeloma)
Sodium per volume of serum may decrease even though amount of sodium per unit of water is appropriate
Treatment of hyponatremia
Treat underlying condition Restrict free water Loop diuretic Hypertonic saline if severe Vasopressin receptor antagonists (conivaptan, tolvaptan)
Central pontine myelinolysis
Occurs when sodium is corrected by more than 12-20 over 24 hours or overcorrected to above 140
Sxs irreversible - delayed 2-6 days after correction of hyponatremia
Dysarthria Dysphasia Paraparesis or quadriparesis Behavioral disturbances Lethargy Coma
CT/MRI 4 weeks after event - areas of demyelination
Hypernatremia
Causes:
Dehydration
Osmotic diuresis
Diabetes insipidus
Presentation: oliguria Thirst Weakness, lethargy Mental status changes Seizures
Tx:
Correct the volume status
Reduce sodium by no more than 12/day to avoid cerebral edema
