Nephrology Flashcards
Glomerular testing
- large protein proteinuria (albuminuria) or urine albumin or PCR
- hematuria/casts on microscopy
- Cr, BUN, GFR, lytes, PO4, Ca, VBG (usually high levels of K, PO4 in serum) (anemia nad high PTH may be seen)
Imaging: DTPA-GFR nuclear med scan
Tubular testing
Urine: mild, small protein proteinuria, tubular indices: glucosuria, aminoaciduria, phosphaturia, Na, K etc
Blood: Cr, BUN, GFR, lytes, PO4, Ca, VBG (usually low levels of K and PO4)
Nephritic syndrome
4 cardinal features
- hematuria
- proteinuria
- hypertension
- renal dysfunction
Post-infection GN
- features
- 10-14 days after infection (strep)
- C3 level is low (normal within 8-12 weeks)
- ASOT is high
- proteinuria should disappear by 6 months
HSP GN
- features
- IgA mediated small vessel vasculitis
- skin, joints, GI, kidneys
- 40% of HSP develop nephritis (within 6 months)
- symptomatic control
- possible steroids for severe skin/GI/renal involvement
IgA nephropathy
- features
= red flags
- URTI trigger
- gross hematuria 1-2 days after URTI
- only lasts a few voids/days
Tx = ACEi or ARB or steroids if severe
Red flags: First Nations, male, persistent proteinuria, renal dysfunction at dx, evidence of frank nephritic/nephrotic
Low complement GN
- SLE nephritis - low C3 and C4
- MPGN - low C3 that persists
- PIGN - low C3 resolves in 8-12 weeks
Nephrotic syndrome
4 cardinal features
- proteinuria
- hypoalbuminemia
- edema
- hypercholesterolemia
Complications of nephrotic syndrome
- infections (loss of IgG, complement factors)
- clots - loss of antithrombin III, protein C + S, hemoconcentrated/high fibrinogen
- shock, IV volume depletion
- hypercholesterolemia
Red flags for nephrotic syndrome (7)
- African Canadian
- age < 1 yr, or pubertal
- renal failure
- gross hematuria
- unresponsive to 4 weeks of steroids
- HTN
- features of SLE, malignancy, infection
Benign orthostatic proteinuria
- seen in up to 5% of teen population
- positive orthostatic test (first am urine PCR normal, afternoon is elevated)
- will outgrow by age 20-30
- may need to monitor
Wide anion gap metabolic acidosis
differential
MUDPILES
- methanol
- uremia
- DKA
- propylene glycol, paraldyhyde
- iron, isoniazid
- lactic acid
- ethyanol, ethylene glycol
- solvents, saliculates
Non-anion gap metabolic acid
- DDX
Renal: RTA, renal failure
GI: diarrhea, pancreatic fistula
Renal tubular acidosis - proximal
Proximal RTA (type 2)
- acidosis
- renal K wasting (possibly hypokalemia)
- renal Na wasting (possible hyponatremia)
- renal PO4 wasting (posisbly hypoP and renal rickets)
- aminoaciduria
- high urine alpha-1MG
- glucosuria
RTA
- distal
Distal RTA (type 1)
- alkalotic urine (despite metabolic acidosis)
- hypercalciuria usually present
- hypocitraturia
RTA - type 4
RTA type 4 = alodsterone issues
- decreased aldosterone secretion
- HYPERkalemia
- hyponatremia
Nephrolithiasis - most common stones
- Calcium
other causes = struvite, uric acid, metabolic - cystinuria, xanthinuria etc
Treatment of calcium stones
- high fluid intake
- low Na intake
- citrate therapy
- HCTZ for hypercalciuria
- treat hypercalcemic states
- rarely: ESWL shock wave lithotripsy or surgery
Struvite stones features
- staghorn calculi
- urease-splitting organisms e.g. proteus
- often in urology pts with complex systems
Tubulointerstitial nephritis (TIN)
- presentation
- causes
- sterile pyuria
- AKI
- renal tubular wasting
Causes:
- infection, drugs, collagen vascular disease, idiopathic
Bartters
= genetic form of lasix (loop of henle)
- low Na, low K, low Cl, alkalosis, normal BP, high renin
Gittelman
= genetic form of HCTZ (convoluted tubule)
- low Na, low K, low MAGNESIUM, alkalosis, high renin
Nephrogenic diabetes insipidus
inheritance
90% = x-linked 10% = AR
Alport’s features
- X-linked 85% (rarely AD or AR)
- mutation in type 4 collagen (GBN)
- hematuria and proteinuria, renal dysfunction over time
other manifestations: hearing loss, ocular (anterior lenticonus), lyomeiyoma
HUS triad
- AKI (oliguric)
- anemic - coomb’s negative hemolytic anemia, shistoctyes on smear
- thrombocytopenia