Nephrology Flashcards
Most common form of Nephrotic Syndrome - key features + x2 complications
Minimal change disease = <6 years old at presentation, no HTN, normal renal function + complement, no hematuria
- Peritonitis (S. pneumo, E.coli), hyper-coagulable
x5 criteria for SIADH
- HypoNa with reduced serum osmolality
- Urine osmolality elevated (compared to serum)
- Urinary Na concentration excessive for extent of hypoNa
- Absence of volume depletion
- Normal renal, adrenal, and thyroid function
Causes and investigations for urolithiasis
Causes: HyperCa, hypocitraturia, hyperoxaluria, infection, polycystic kidneys, RTA, endo (hypothyroidism, hyperparathyroid, excess adrenocorticoid), drugs (loop diuretics, excess vitamin D), bone metabolism (rickets, immobilization)
Imaging: US/CT/XR, lytes, renal function, UA +/- UCx, 24 urine collection, stone analysis, TSH/PTH/vit D
x3 types of RTA and characteristics
Type I: Distal. Inability to secrete H+. HypoK, urine pH >5.5.
Type II: Proximal. Decreased ability to reabsorp bicarb. HypoK, urine pH <5.5.
Type IV: Aldosterone deficiency. HyperK, urine pH <5.5.
When to consider RTA (clinical signs/symptoms/acid-base result)?
- HyperCl metabolic non-AG acidosis
- Growth failure
- Emesis, dehydration
- Polyuria, polydipsia
- think DKA but not
Differences between primary and secondary adrenal insufficiency - clinical presentation, hormones
Primary: Abnormality of adrenal gland = dec cortisol, inc ACTH (hyperpig), +/- mineralocorticoid deficiency (hypoNa, hyperK).
Secondary: Hypothalamic + pituitary dysfunction = dec cortisol, N/low ACTH (no hyperpig), normal mineralocorticoid.
SIADH vs cerebral salt wasting
SIADH = Intravascular euvolemic or overload. Fluid restriction leads to increase in serum Na. CSW = Intravascular volume depletion. Fluid restriction will NOT increase Na and will further impair intravascular volume.
DI - clinical presentation (no Ix)
Dehydration, polyuria, nocturia, polydipsia
Glomerular hematuria - history, exam, and UA
- Hx: tea/coca-cola urine, flank pain, systemic c/o (edema, fatigue, pharyngitis, fever, rash, arthralgia), recent infection, fmhx (hearing loss, renal failure)
- PEx: HTN, edema, systemic features, sx of infection
- UA: brown/tea/cola urine, proteinuria, dysmorphic RBCs, red cell casts
Causes (x2) of heme positive UA but RBC absent
Free hemoglobin - hemolysis
Myoglobin - rhabdomyolysis
Most common cause of hereditary type 2 RTA?
Cystinosis
Most common type of stone
Calcium carbonate
Eagleton Barrett Syndrome - classic triad?
Minimal abdo muscles, undescended testes, CAKUT
IgA nephropathy - natural history of initial presentation
-Synpharyngitic hematuria –> following URTI by 1-2 days
Glomerulonephritis with low C3 (x5)
- Post-infectious GN
- Membranoproliferative GN
- Lupus nephritis
- C3 glomerulopathy
- aHUS
Nephrotic syndrome - classic 4 features
- Proteinuria
- Hypoalbuminemia
- Edema
- Hypercholesterolemia
Pollakuria - what is this, typical age range, most common cause?
=extraordinary daytime urinary frequency (up to 50x/day)
- in 5-6 years olds typically
- context of recent death or life-threatening event
- benign or self-limited (lasting ~6 months)
Bladder capacity - equation and amount for >12 yo
= 30 + (age x 30)
-390mL
Nocturnal enuresis - prevalence
- 5 yo = 20%
- 7 yo = 10%
- Resolves at rate of 15% per year
- 15 yo = 1-2 %
- M>F
Nocturnal enuresis - causes/theories
- Delayed maturation
- Decreased secretion of ADH at night
- Genetic influence
- Small bladder capacity
- Difficulty waking from deep sleep
Nocturnal enuresis - treatment options
- Dry bed training + lifestyle modifications
- Enuresis alarms
- Desmopressin
Causes of hyperK
- Increased intake: IV fluids
- Abnormal excretion: pseudohypoaldosteronism (CAH, adrenal insufficiency, drugs), renal impairment, decreased circulating volume, impaired tubular excretion
- Intracellular shifts: metabolic acidosis, B blockers, cellular damage (hemolysis, rhabdo, TLS)
- PseudohyperK: hemolyzed sample, leukocytosis/thrombocytosis
Treatment options for hyperK
- Stabilize cardiac membrane: Ca gluconate
- Intracellular shifts: sodium bicarb, ventolin, insulin
- Increased removal: kayexylate, diuretics
Causes of hypoNa
- Hypovolemic: low urine Na (GI losses, pancreatitis, skin losses, lung losses), high urine Na (RTA, diuretics, adrenal insufficiency)
- Euvolemic: SIADH, DI, adrenal insufficiency
- Hypervolemic: low urine Na (cirrhosis, CHF, renal failure), high urine Na (renal failure)
Indications for dialysis
- A: acid-base problems
- E: electrolyte abnormality
- I: intoxication
- O: overload fluid
- U: sx of uremia (pericarditis, encephalopathy, seizures, bleeding)
When do neonatal Cr levels hit + stay at 20?
Approximately 2-3 months
Equation to calculate eGFR
36.5 x height / serum Cr
Equation to calculate FeNa
% = (urine Na x plasma Cr) / (urine Cr x plasma Na) x100%
KDIGO stages of AKI
- Cr 1.5-1.9x, UO <0.5 x6-12h
- Cr 2.0-2.9x, UO <0.5 x>12h
- Cr >3.0x, UO <0.3 x>24h or anuria x12h
Post-renal AKI causes
- UPJ obstruction
- Ureteric obstruction
- Inflammatory
- Malignancy
- Bladder obstruction
- Neurogenic bladder
- Interstitial cystitis
- Urethral obstruction
- Congenital stricture
Renal AKI causes
- Tubules/interstitium: ischemic tubular injury, nephrotoxic AKI acute interstitial nephritis
- Glomerular: post-infectious GN, HUS
- Vascular: renal vein thrombosis
Pre-renal AKI causes
- Bleeding: GI losses
- Cardiac: decreased CO
- Sepsis
- Nephrotic syndrome
- Impaired renal autoregulation: hyperCa, ACEi, NSAIDs, calcineurin inhibitors
Definition of Chronic Kidney Disease
x3 months of:
- At least 1 marker of kidney damage: albuminuria, ACR >30mg/g, urine sediment abnormalities, electrolye abnormality, histological findings, structural abnormalities on US, hx of transplantation
- Decreased GFR to <60
Stages of Chronic Kidney Disease
- GFR >90
- GFR 60-90
- GFR 30-60
- GFR 15-30
- GFR <15 or dialysis
In order the most common causative categories (x5) for chronic kidney disease?
- Renal dysplasia +/- obstruction and reflux
- Glomerulopathy
- Cystic kidney disease
- Ischemic - ATN
- Others - nephrotoxins, interstitial nephritis, Wilm’s tumor
x8 roles of the kidney with associated complications during renal failure
- Salt/water balance: oliguria/overload/dehydration
- Removal of toxins: uremia
- Potassium balance: hyperK
- Ca/PO4/vit D: hypoCa/hyperPO4/hyperPTH
- Nutrition/growth: FTT, inadequate nutrition
- BP: HTN
- Hb: normocytic anemia
- Acid-base: metabolic acidosis
What x2 important features to look for in multicystic dysplastic kidney disease?
- Contralateral kidney compensatory hypertrophy
- Reflux
What is worse autosomal dominant polycystic kidney disease or autosomal recessive polycystic kidney disease?
- ADPKD = no major issues in childhood
- ARPKD = high morbidity/mortality
Clinical presentation of ARPKD
- Oligohydramnios, Potter’s sequence
- Large echogenic kidneys
- HTN
- UTIs
- Tubular dysfunction
- Pulmonary hypoplasia
- Hepatic involvement (varices, HSM, cholangitis)
Features of Potter’s sequence
- From oligohydramnios
- Deep set eyes, beaked nose, micrognathia, low set ears, extremity contractures
Non-blood and non-renal causes of a query hematuria presentation
- Non-blood: Food = beets, blackberries, Free Hb, myoglobin, urate crystals, Drugs = rifampin
- Non-renal: Fever, drugs, exercise, menses, coagulopathy
Renal causes of hematuria
- Glomerular: Post-infectious GN, IgA nephropathy, HSP, HUS, SLE, ANCA vasculitis, Anti-GBM disease, Thin basement membrane disease, Alport syndrome
- Non-glomerular: hyperCa, Nephrolithiasis, Sickle cell disease/trait, Renal cysts
Glomerular vs non-glomerular hematuria clues on investigations
- Glomerular: brown/tea, RBC/cellular casts, proteinuria, dysmorphic RBCs
- Non-glomerular: red-pink, blood clots, no proteinuria, normal RBCs
Glomerular causes of hematuria based on C3 and renal/systemic?
- Low C3/renal: PSGN, MPGN, C3 glomerulopathy
- Low C3/systemic: SLE, shunt nephritis, subacute bacterial endocarditis
- Normal C3/renal: IgA nephropathy, anti-GBM disease, ANCA-associated vasculitis, hereditary nephritis
- Normal C3/systemic: IgA vasculitis, granulomatosis with polyangiitis, Goodpasture’s, Alport’s
Work-up for GN
- Renal function
- Albumin
- CBC
- Complement - C3, C4, +/- CH50
- Inflammatory - ANA, dsDNA, ANCA, immunoglobulins
- Infectious - throat swab, ASOT, +/- anti-DNAse B, hep B, hep C
- UA + urine microscopy
- Renal ultrasound with doppler
When does PSGN present following infection?
- Pharyngitis: 1-2 weeks
- Skin infection: 3-6 weeks
Management for PSGN
- Fluids/salt restriction
- Furosemide 1-2 mg/kg/day
- Short + long-acting anti-hypertensives
- AKI management
- Continue to follow HTN + C3 until normal
When would you reconsider your diagnosis of PSGN?
If C3 does not normalize by 8-12 weeks
What does monitoring look like for IgA vasculitis/nephritis?
- Weekly UA + BP until rash resolves
- Then monthly for total of 6 months until hematuria resolves
What hereditary GN is progressive and often leads to kidney failure?
Alport Syndrome
Associated findings (x2) with Alport Syndrome
- Anterior lenticonus
- SNHL
Triad for HUS
- Thrombocytopenia
- MAHA
- AKI
Trick to remember threshold for abnormal + nephrotic range proteinuria based on method of investigation
- C-P-A = 4-20-30
- x10 for nephrotic range
What is the best way to test for orthostatic proteinuria?
- First AM void = should be negative
- Urine 3-4 hours after ambulation = should be +
- PCR can be used
Dosing of steroids for initial therapy of classic nephrotic syndrome
60 mg/m2 x6 weeks, then 40 mg/m2 x6 weeks
Complications of nephrotic syndrome + when to consider admission?
- Severe edema: resp distress, massive ascites, inability to move
- Impaired renal function
- Symptomatic HTN
- Thrombosis
- Infection
x2 most common causes of nephrotic syndrome in children
- Minimal change disease
- Focal segmental glomerulosclerosis
x4 criteria for dx of nephrotic syndrome
- Proteinuria
- Edema
- Hyperlipidemia
- Hypoalbuminemia
What will happen if you correct hypoNa too quickly?
Osmotic demyelination syndrome
What will happen if you correct hyperNa too quickly?
Cerebral edema
What is the definition of chronic hypoNa?
> 48 hours
Management of SIADH?
- R/o thyroid + adrenal cause
- Fluid restriction
- +/- lasix + salt supplementation
Water deficit equation
§ Water deficit = [(pt Na - desired Na) / desired Na)] x TBW
Characteristics of proximal/type 2 RTA
- Unable to resorb bicarb (but distal tubule picks up the slack) = pH <5.5
- HypoK
- Often will grow out of it
- Fanconi syndrome (decreased absorption of a.a., glucose, and PO4)
Causes of proximal/type 2 RTA
- Drugs
- Fanconi Syndrome
- Primary genetic
Characteristics of distal/type 1 RTA
- Unable to acidify urine secondary to H+ loss = pH >5.5
- HypoK
- Nephrocalcinosis
- Generally do not grow out of it
Causes of distal/type 1 RTA
- Primary genetic (SNHL)
- Autoimmune (SLE)
- Drugs
- Cirrhosis
Management of proximal RTA
-High doses of bicarb (because proximal tubule in the primary site for bicarb absorption)
Management of distal RTA
-Smaller doses of bicarb
Characteristics of type 4 RTA
- Aldosterone deficiency
- HyperK
- pH <5.5
What RTA is most likely to have stones
Distal or type 1
Management of type 4 RTA
- Volume expansion
- K restriction
- K wasting diuretics
What diuretic mimics Bartter Syndrome vs Gitelman Syndrome?
- Bartter = lasix
- Gitelman = HCTZ
How do we make BP measurement the most accurate?
- BP cuff of appropriate size = bladder width 40% and length 80-100% of arm circumference
- Lower end of cuff 2-3cm above antecubital fossa
- Right arm
- Avoid stimulants, caffeine, smoking prior
- Resting for 3-5 minutes, straight legs
Definitions for HTN in children 1-13 years old
- Normal = <90th%tile
- Elevated BP = 90-95th%tile
- Stage 1 HTN = 95-95th%tile +12
- Stage 2 HTN = >95th%tile + 12
Definitions for HTN in children >13 years old
- Normal = <120/80
- Elevated BP = 120/80-129/89
- Stage 1 HTN = >130/90
- Stage 2 HTN = >140/90
When to start measuring pediatric BP
At age of 3 or if RF’s before that
What risk factors would make you consider measuring BP prior to age 3
- History of prem, SGA, or VLBW
- Neonatal complications (lines)
- CHD (repaired or unrepaired)
- Recurrent UTIs, hematuria, proteinuria
- Known renal disease or urologic malformations
- Fmhx of congenital renal disease
- Solid organ transplant
- Malignancy or BM transplant
- Tx with drugs known to raise BP
- Other systemic illness associated with HTN (SCD, NF, TSC)
- Evidence for elevated ICP
Examples of end organ damage associated with HTN
- Coronary ischemia
- Hypertensive encephalopathy
- Papilledema
- Stroke
- Intracerebral hemorrhage
- CHF
- Pulmonary edema
- Kidney failure
Most common etiologies for HTN in newborn
- Renovascular
- Congenital or acquired renal abnormalities
- Cardiac
- Neuro
- Meds
Most common etiologies for HTN in 1-18 years
- Renal parenchymal
- Renovascular
- Coarctation
- Essential
- Meds/iatrogenic
- Endo
Initial investigations with HTN
- UA, ACR
- US with doppler
- Echo
- Retinal exam
- Labs: lytes, renal function, fasting BG, TSH, lipid/cholesterol panel
Goal of HTN therapy
-Reduce to <90th%tile or <130/80 in children >13 years old
Top 3 choices for anti-hypertensive therapies
- CCB
- Diuretics
- ACEi/ARB
Definition of hypertensive urgency vs emergency
- Urgency = severe elevation in BP without end organ damage
- Emergency = end organ damage
What to think of with undescended testes, abdo laxity, and abdo masses (+what is the cause of the masses)?
Prune Belly Syndrome - hydronephrosis
What should you do to differentiate epididymitis from torsion?
Cremasteric reflex - absent in torsion
Bugs associated with epididymitis
- Younger, non-sexually active children: E.coli, viruses (mycoplasma)
- Older: C+G
Treatment for epididymitis
- Rest
- Testicle support
- NSAIDs
- Abx - empiric if clinical evidence for an associated UTI or if urine culture demonstrates associated UTI
- If bacterial = arrange for urology consultation + VCUG
When to treat HTN with pharmaceuticals?
- If stage 1 HTN and no improvement x6 months
- If stage 2 HTN or above
- If evidence for end-organ involvement
- If symptomatic HTN
If a child with high grade VUR has urinary bugs that are resistant to septra + nitrofurantoin what should you do?
Discontinue prophylaxis - using a broader spectrum Abx carries the risk of causing more resistance
Tx for testicular appendix
NSAIDs + scrotal support
What side does UPJ obstruction occur on typically?
left (60%)
What x2 imaging studies would you do after confirming an ipsilateral UPJ obstruction US?
- VCUG (10-15% have ipsilateral reflux)
- MAG3 = diuretic renogram (Hamilton lecture said this one)
What should you think about in a neonate with glucosuria?
Cystinosis
When would you consider removal of kidney stone?
Septic stone
Single kidney
Obstructed stone
>6mm
