Urology/ Nephro Flashcards
most common cause of congenital obstructive uropathy
ureteropelvic junction (UPJ) obstruction
Most common causes of UTIs in boys
vesiculoureteral reflux
When is hypertonic 3% saline indicated
- Serum sodium concentration < 120 mEq/L
- patients with associated neurologic manifestations such as headaches, seizures, behavioral changes, obtundation, coma, and respiratory arrest
Alport Syndrome
pathophys & clinical clues
Inherited disorder of basement membrane collagen
persistent microscopic hematuria (with RBC casts) with proteinuria
family history of renal disease and deafness
X-linked dominant AS
Increased urinary excretion of ____, ___, ___ is associated with decreased risk of renal stone formation
citrate, magnesium, pyrophosphate
Urinary metabolic evaluation process
24-hour urine collection, needs to be at home without IVF
hyper_____ is the most commonly identified metabolic cause of renal stones
hypercalciuria
Boy with proteinuria on UA x2 instances, 6 months apart. What is the next evaluative step?
First-Morning urinalysis
(Urine protein/Creatinine ratio >0.2 in first-morning sample is abnormal.)
Then Renal US if proteinuria is confirmed
(don’t really do 24-hour urine collection for proteinuria in adults or kids)
Cut off for urine dipstick to make protein appear positive
300 mg/day
Normal
What is benign proteinuria?
Orthostatic proteinuria (when active), and disappears when patient is supine/asleep for at least 2 hours (first-morning sample)
Potter syndrome
Autosommal Recessive PKD
- oligohydramnios
- pulmonary hypoplasia
- facial appearance (pseudoepicanthus, flattened ears and nose, recessed chin)
- skeletal abnormalities (hemivertebrae, sacral agenesis)
- ophthalmologic malformations (cataracts, lens prolapse)
- limb abnormalities (club feet, hip dislocation)
Ultrasonographic findings of Potter Syndrome
Large echogenic kidneys with decreased corticomedullary differentiation
hepatic echogenicity is possible
Causes of asymptomatic gross hematuria in adolescent boys
Usually there is an obvious underlying cause
Trauma
Familial nephritis
HSP
Ddx and Workup of gross hematuria in children
detailed H&P, urinalysis, workup of infection, renal US
Ddx: meatal/prineal irritation, calciuria (crystalluria), nephrolithiasis, cystitis, congenital renal anomalies, bladder mass
Most common extra-renal manifestation of ADPKD, other manifestations, and pathophys
cerebral aneurysm
Others include: hepatic, pancreatic and seminal vesicle cyst; cardiac valve disease (MVP, Aortic Regurge); colonic diverticulal abd wall hernia
Pathophys: defective epithelial cell differentiation or extracellular matrix function associated with genetic abnormality in ADPKD
First dx test to check if children have ADPKD (if they have positive family hx)
Renal US (to look for cysts): need 3 unilateral or bilateral kidney cysts. PPV 100%, sensitivity 82-96%.
If there is a murmur: need echo
Most common manifestation of ARPKD and how to diagnose
liver abnormalities (congenital hepatic fibrosis, portal HTN, perilobular fibrosis and ‘Caroli Syndrome’)
Dx: antenatal US at 24wks gestation
Causes of UTI in prepubertal girl >2yo
posterior urethral valves
+ foreign body or labial adhesions
Most common pathogen causing lower urinary tract infections
E. Coli
Bartter Syndrome
Syndrome caused by defect in NaCl reabsorption in medullary thick ascending limb of loop of Henle
Similar to chronic furosemide therapy
Presents as growth restriction, hypoK, metabolic alkalosis and polyuria
volume depletion from salt wasting
Gitelman Syndrome
Syndrome cause by mutation in gene coding for thiazide-sensitive NaCl transporter in DISTAL TUBULE
Causes hypo K, polyuria, polydipsia
Presents in late in childhood or adulthood with muscle cramps
Reduced urinary calcium and hypomagnesemia
** volume depletion** from salt wasting
Gordon Syndrome
Syndrome causing pseydohypoaldosteronism (decrease Na reabsorption and K secretion) low Na, high K, high H+
in DISTAL TUBULE
- Diminished renin secretion
metabolic acidosis
Liddle Syndrome
Syndrome causing pseudoaldosteronism (increased Na reabsorption and K secretion) high Na, low K in COLLECTING TUBULES
AD
Most likely cause of bilateral hydronephrosis, dilated bladder, thickened bladder wall, and dilated posterior urethra
Posterior Urethral Valves
Initial serum creatinine concentration reflects maternal serum level. When does it normalize? (preterm vs. FT)
7-10 days FT
1 month preterm
Difference between ARPKD and multicystic dysplastic Kidney (MCDK)
MCDK = usually ONE kidney
MCDK involves the whole kidney. On US shows unilateral multiple noncommunicating cysts of varying sizes with intervening dysplastic renal tissue. This kidney will not be functional. The other might have complications
Vesicoureteral reflux
- age of presentation (dx)
- complications
Dx and age: prenatally on maternal US screening, after episode of UTI (6-7yo)
- can be secondary with high pressures in bladder (2/2 posterior urethral valves or closed urethral sphincter)
- Increased risk of pyelonephritis
Management of VUR
- Abx ppx
- surgical correction
Prognosis of Cesicoureteral reflux
- grade I-II have high rates of resolution
grade III-IV only 10-20% self resolution
Grade V rarely resolves spontaneously
If dx before age 1 yo, favorable association with spontaneous resolution
FeNA formula
[Urine Na x serum Cr] / [Serum Na x urine Cr] x100
Winters formula (assess respiratory compensation for metabolic acidosis)
pCO2 = (1.5x HCO3) + 8
(+/- 2)
What is the delta-delta ratio and what does it assess?
Delta ratio = [measured AG - normal AG]/[normal bicrb - measured bicarb]
If delta ratio >1 pure increased AG acidosis
If delta ratio <1, mixed increased AG and normal AG metabolic acidosis
Tyle 1 RTA (location, channel effected, lab findings)
H+ problem (1st element in periodic table)
Distal
Inability to acidify urine
Urine pH >5.5
Labs:
Low K
+ Urine AG
Hyper Ca + nephrolithiasis (phosphate kidney stones)
(causes: Lithium, SLE, amphoterecin B)
Type 2 (location, channel effected, lab findings)
2 = bi = bicarbonate
Problem reabsorbing bicarb in proximal tubule
pH <5.5
Low to normal K
May be associated with Fanconi syndrome, Multiple myeloma
Type 4 (location, lab findings)
4 (kind of looks like K)
Distal
Low aldosterone/ aldosterone insensitivity
Labs:
LOW K
Causes: bactrim, Gordon sd, CAH
FSGS tx
ACE/ARB
Preventative care for patients with nephrotic syndrome
PPSV23
Difference between poststreptococcal GN and IgA GN
postreptococcal timing is at least 1wk post infection to 3-6wk post skin infection (ASO negative in skin strep infection)
IgA GN is 2 DAYS after infection
MPGN Labs
low C3
Normal C4 (type 2)
Low C4
Post GN after infective endocarditis complement levels
low C3, low C4
Painless gross hematuria concurrent with illness (URI). Dx and how to evaluate
Dx: IgA GN
Biopsy to diagnose.
C3 is normal, IgA can be elevated but not always.
key is concurrence
Non-thrombocytopenic palpable purpura, arthritis, GI sx, nephritis. Dx and Tx?
HSP
often self limited
ACE/ARB if proteinuria >0.5g/day
Steroids if nephritis continues on ARB/ACEi
Anti C1q ab in serum in patient with renal disease
think Lupus nephritis
Infectious association of membrenoproliferative GN
Hep B
Hep C
cryoglobulinemia
lupus (not infective)
First line treatment for nephrotic syndrome
prednisolone/prednisone
ACE-i is adjunctive
No need to give furosemide unless clinically with HTN or crackles on lung exam
First line for Poststreptococcal GN
furosemide if HTN
Supportive care
If need be, CCB would be the preferred anti-hypertensive med (or nicardipine, nitro gtt, labetalol in hospital settings)
- no steroids or ACE-i
When must you get a Renal US and VCUG
Renal US after UTI treated or >48h if no improvement for evaluation of renal abscess or pyonephrosis
- urine with 50,000 or more cfu of single organism (suprapuic aspirate)
- Voided urine sample or bag, >100,000 cfu
- <24mo
VCUG if there is hydronephrosis, scarring or other signs of urinary obstruction
FeNa and how to interpret
Urine Na x serum cr /
serum Na x urine cr
<1% prerenal
>2% renal (also urine to plasma osm is <1.5, SG <1.010)
When do you repeat a BP for patients with elevated BP?
If >95th +112 mmHg (stage 2), in 1 week, then if still high, start diagnostic eval
If > 95th percentile (stage 1), must be in 1-2 weeks, then if still high, in 3 mo for the 3rd
If >90th percentile, in 6 mo, then 6 mo
Diagnostic evaluation of child with HTN
urinalysis
CMP
lipid profile
renal ultrasound
When does maternal creatinine get cleared in term vs. preterm neonates
1-2 weeks
Preterm: 1-2 mo
When does maternal creatinine get cleared in term vs. preterm neonates
1-2 weeks
Preterm: 1-2 mo
When does GFR reach adult values
2 yo
