Nephrology / Urology Flashcards
1
Q
What is the typical age of onset for post-strep glomerulonephritis?
A
5-12-years old (rare <3yo)
2
Q
What are reasons to consider a renal biopsy in PSGN to look for an alternative diagnosis?
A
- Presence of acute renal failure, nephrotic syndrome, absence of evidence of strep infection, normal complement levels
- Or when hematuria + proteinuria is present and: diminished renal function and/or lo C3 level persists more than 2mo after onset
- Alternative dx: lupus nephritis, endocarditis, membranoproliferative GN
3
Q
What are the 4 most common causes if high grade congenital hydronephrosis?
A
- UPJO: Ureteropelvic junction obstruction
- High grade VUR: high grade vesicoureteral reflux *
- UVJO: ureterovesical junction obstruction *
- PUV: posterior urethral valves *
*dilated kidney & hyroureter -> can look identical
4
Q
What is the most common enzyme defect in CAH?
A
21-hydroxylase (enzyme) deficiency (95% of cases)
5
Q
What is the differential diagnosis for acute glomerulonephritis and decreased serum complement levels (C3, C50)?
A
- Systemic diseases: Lupus nephritis, subacute endocarditis, shunt nephritis, essential mixed cryoglobulinemia, visceral abscess
- Renal disease: acute PSGN, membranoproliferative GN Type 1
6
Q
What is the differential diagnosis for acute glomerulonephritis and normal serum complement levels (C3, C50)?
A
- Systemic diseases: polyarteritis nodosa, hypersensitivity vasculitis, Wegener’s granulomatous disease, HSP, Goodpasture’s
- Renal disease: IgA nephropathy, Idiopathic rapid progressive GN (Type 1, 2, 3), post-infectious NG (non-streptococcal)
7
Q
What is the treatment for post-strep glomerulonephritis?
A
- 10 day course of Penicillin (does not alter course but limits spread)
- Sodium restriction
- Diuresis with IV lasix
- HTN - Ca channel blockers, vasodilators, ACEi
8
Q
What is the recommended investigations for a child with confirmed hypertension?
A
- Tests for underlying etiologies - renal (Cr/Urea/lytes, UA, AUS), CBC (CKD)
- Tests for comorbidities (fasting lipid panel, fasting glucose); sleep study & drug screen if indicated by hx
- Target organ damage (echo for LVH & R/O coarctation, retinal exam, albumin-Cr ratio)
8
Q
What is the recommended investigations for a child with confirmed hypertension?
A
- Tests for underlying etiologies - renal (Cr/Urea/lytes, UA, AUS), CBC (CKD)
- Tests for comorbidities (fasting lipid panel, fasting glucose); sleep study & drug screen if indicated by hx
- Target organ damage (echo for LVH & R/O coarctation, retinal exam, albumin-Cr ratio)
9
Q
What are factors that suggested a diagnosis OTHER than idiopathic MCNS in nephrotic syndrome?
A
- Age <1y (probably congenital NS) or >10y (more likely membranous, SLE, etc.)
- Black race (more likely SLE, FSGS)
- FHx of kidney disease
- Chronic disease of another organ or systemic disease
- Sx due to intravascular volume expansion (hypertension, pulmonary edema)
- Kidney failure
- Active urine sediment (RBC casts)
- Other red flags: failure to respond to 4wk steroid tx, macrohematuria, microhematuria with HTN in remission
- Low complement levels
10
Q
What is the treatment for typical nephrotic syndrome?
A
Steroids 2mg/kg (max 60mg) PO x6wk with a 4wk taper
NS & Fluid restriction
11
Q
What are the complications of nephrotic syndrome?
A
- AKI
- Thromboembolic disease (e.g. DVT, PE) - due to loss of AT3, protein C/S and increased fibrinogen
- Infection - due to loss of IgG, e.g. spontaneous bacterial peritonitis (esp. pneumococcus)
- Hypercholesterolemia
- Side effects of steroids
12
Q
What are the 4 most common causes of high grade congenital hydronephrosis?
A
- UPJO
- High grade VUR
- UVJO
- PUV
13
Q
What is the most reliable imaging test to detect nephrolithiasis
A
Most reliable: CT KUB (but this is second line)
1st line: renal ultrasound (may miss small ureteric stones)
14
Q
What are the most likely pathologies to cause AKI in children?
A
- Pre-renal AKI (especially due to hypovolemia)
- HUS (R/O early)
- ATN (usually post-hypotensive episode in OR, MVA)
- PSGN
- SLE PMGN
- HSP
15
Q
What are the atypical features for nephrotic syndrome?
A
- Age < 1yo
- Persistent HTN (BP > 95th %)
- Persistently decreased renal function (eGFR < 90)
- Significant or gross hematuria (>50 RBCs/HPF)
- Steroid resistant NS
16
Q
What is the definition of steroid resistant in nephrotic syndrome? What are the different types of non minimal change NS?
A
Persistence of proteinuria after six weeks of daily prednisone therapy (urine dipstick 1+, U/A 0.3g/L+, or urine PCR 25mg/mmol+ on a 1st morning urine sample)
Focal segmental glomerulosclerosis (FSGS), membranoproliferative glomerulonephritis (MPGN), membranous nephropathy
17
Q
What is the formula for calculating free water deficit?
A
Free water deficit = total body water (TBW) x ([current plasma Na+/140] - 1)
18
Q
What are the potential complications of PSGN?
A
- CHF due to HTN or hypervolemia
- HTN encephalopathy → change in LOC, seizures, blurred vision, HAs
- Nephrotic syndrome (occurs in <5% of cases)
- Acute renal failure
- Electrolyte imbalances (hyper-K/P, Hypo-Ca, uremia, acidosis)
19
Q
What are features that can be used to differentiate testicular torsion from torsion of the testicular appendix?
A
- Pain → more severe (typically) + sudden onset
- N/V → often (occasionally seen in appendix)
- Testis position → +/- high riding, +/- transverse lie
- Testis tenderness → throughout
- Cremasteric → often absent
- Blue dot → NEVER present
20
Q
What are the definitions of pre-HTN, Stage HTN?
A
- HTN: avg sBP and/or dBP that is ≥ 95th % for age, sex & height on ≥ 3 occasions
- Stage 1 HTN: 95-99th + 5mmHg -> if asymptomatic, non-urgent
- Stage 2 HTN: >99th + 5 mmHg -> urgent evaluation & therapy
- Pre-HTN: avg sBP and/or dBP that is ≥ 90th % but < 95th %
21
Q
What are the pediatric populations at greater risk of hypertension? How often should children + children with RFs be screened?
A
- Obesity
- Sleep disordered breathing
- CKD
- Prematurity
- 3yo + RFs: every visit
- 3yo + no RFs: every year
- Meds to consider RF: caffeine, decongestants, NSAID, ADHD, OCP, steroids, TCA
22
Q
What is the work-up for confirmed hypertension?
A
- Tests for underlying etiologies
- Hx/OE - sleep, FHx, diet, habits, substances
- RFTs, lytes, UA, urine culture
- CBC (anemia in CKD, as indicated by history)
- Renal US
- Tests for comorbidity
- Fasting lipid panel (TC, LDL, HDL, TG), fasting glucose
- Drug screen (as indicated by history)
- Polysomnography (OSA) (as indicated by history)
- If obesity:
- HbA1c, ALT/AST, fasting lipid profile
- Target organ damage:
- Echo (for LVH & R/O coarctation)
- Retinal exam
- Albumin-Cr ratio (morning)
- Additional as indicated:
- Ambulatory BP monitoring (white coat, when BP pattern is needed)
- In Canada, limited availability, to be ordered by expert in HTN
- TSH → as indicated by history
- Plasma renin determination (low renin -> indicated mineralocorticoid related disease)
- Indication: young children with stage 1 HTN + any child or teen with stage 2
- Renal scan -> same indication as above
- Plasma & urine steroid levels -> “
- Plasma & urine catecholamines -> “
- Ambulatory BP monitoring (white coat, when BP pattern is needed)
23
Q
What are risks associated with having a horseshoe kidney?
A
- Wilms much more common
- MCDK more likely
- Increased risk of UPJO (urine must drain up & over the renal parenchyma, most relevant if hydronephrosis)
- Stone disease and HN more likely
24
What investigations should be sent in persistent proteinuria?
* Serum renal function indices
* Serum albumin and cholesterol
* C3/C4 complement, ANA, ESR
* Consider ASOT, anti-DNAase, throat culture if clinically indicated
* HCV, HBV, HIV serology
24
What investigations should be sent in persistent proteinuria?
* Serum renal function indices
* Serum albumin and cholesterol
* C3/C4 complement, ANA, ESR
* Consider ASOT, anti-DNAase, throat culture if clinically indicated
* HCV, HBV, HIV serology
25
What are the indications for a renal biopsy for persistent proteinuria?
* Dixed, asymptomatic proteinuria, \>1g/day
* Persistent hematuria and cellular casts
* Renal insufficiency
* Persistently low complement levels
* HTN
* SLE
* FHx of kidney disease or autoimmune disease
* Corticosteroid-resistant nephrotic syndrome
26
What are the indications for doing a VCUG?
1. SFU III-IV CH
2. 2nd febrile UTI work-up (also consider if poor growth, hypertension, atypical organism)
3. Suspicion of PUV
27
What is the management for low grade and high grade VUR?
* *Grade I and II VUR* → observation, minimizing risk of UTI by behavioural modification (timed voiding, avoiding constipation, increased fluid intake)
* Spontaneous resolution occur in Grade I to III VUR
* *Grade IV and V VUR* → daily antibiotic prophylaxis
* Constipation management
* Circumcision in males can decrease risk of UTIs
* Indications for surgical correction:
* Persistent high-grade VUR, especially in females (concern for UTI/pyelonephritis during pregnancy)
* Worsening renal function or new scarring
* Recurrent UTIs/pyelonephritis
28
A 18 month old M is diagnosed with his 1st febrile UTI. RBUS shows bilateral SFU II HN. A VCUG was ordered and shows bilateral grade III VUR and a normal posterior urethra.
Management, as per the CPS recommendations, is:
A) Parental counseling regarding signs of recurrence
B) Prophylactic antibiotics for 3 months
C) Referral to a Pediatric Nephrologist or Urologist
D) Repeat cystogram (VCUG or NC) in 6 months
Answer: A
## Footnote
**Observation alone is recommended for VUR I-III (bilateral or unilateral) identified following a single febrile UTI**
No antibiotic prophylaxis for **VUR I-III**, even w/ hx of febrile UTI
Referral/discussion w/ Urologist or Nephrologist for **VUR IV-V** or significantly abnormal RBUS findings
Repeat cystogram will not alter management if child remains UTI-free off prophylactic antibiotics
29
Which children \< 3yo should have their BPs checked annually + at every visit?
* Neonate issues (prematurity \< 32wk, SGA, VLBW, UVC, NICU)
* CHD
* Recurrent UTI / hematuria / proteinuria
* Known increased BP
* Renal or urological disease
* FHx of congenital renal disease
* Solid-organ transplant
* Malignant or bone marrow transplant
* Hx aortic arch obstruction
* Diabetes
* Obesity
* Treatments known to raise BP
* Systemic illness associated with HTN (NF1, TS, SCD)
* Signs of increased ICP
30
What is the differential diagnosis for NAGMA? (USED CRAP)
* U = ureteric diversion
* S = sigmoid fistula
* E = excess saline (resolving DKA)
* D = diarrea
* C = carbonic anhydrase inhibitor
* A = addisons
* R = RTA
* P = pancreatic fistula
31
As per the CPS statement, what is the recommended treatment for UTIs?
* Most experts recommend:
* Oral antibiotics first for febrile UTI in non-toxic children with no known underlying abnormality
* Limited evidence for 2-3mo old infants, so some experts recommend IV
* Start empirical based on local susceptibility patterns
* Most areas: Cefixime
* In-patients: Gentamicin +/- Ampicillin
* Other option: Ceftriaxone / Cefotaxime —\> less nephrotoxic
* Length: 7-10 days for febrile UTIs
* Cystitis
* Typical presentation: girls, non-febrile, post-pubertal
* Likely 2-4 day course of oral antibiotics is likely to be sufficient
32
What is the recommendation for screening AUS for renal anomalies?
* Children \< 2 years of age should be investigated _within 2 weeks_ after their first febrile UTI with a renal and bladder ultrasound (RBUS) to identify significant renal abnormalities and grade IV or V VUR.
* A voiding cystourethrogram (VCUG) is not indicated with a first febrile UTI when the RBUS is normal.
* Febrile UTI = to confirm child had pyelonephritis or whether severe VUR or structural anomalies are present
* Should be done when would change management
33
What are signs of a complicated UTI?
* When to be concerned:
* Hemodynamically unstable patients
* Elevated serum creatinine at any time
* Bladder or abdominal mass
* Poor urine flow
* Not improving clinically after 24h of fever
* Fever not downtrending within 48h
* Investigation:
* Start with renal & bladder ultrasound —\> to identify obstruction or abscess
* If complicated identified, give IV until the child is clearly improving
34
What findings on a screening AUS would prompt ordering a VCUG?
* Hydronephrosis, hydroureter
* Small kidneys
* Thick walled bladder
* Renal parenchyma abnormal - scars, cysts
35
In nephrotic syndrome, what are the definitions of: steroid responsive, steroid resistance, frequently relapsing, and steroid dependent?
* Steroid responsive - responsive to prednisone within 4 weeks
* Steroid resistance - proteinuria at 8 weeks (SK says 4wk, often with viral illness, may not develop edema)
* Frequently relapsing - 2 relapses within 6mo of initial presentations or 4 relapses within any 1 year period
* Steroid dependent - relapse while on alternate day steroid therapy or within 28d of stopping steroids
* SK definition: 2 consecutive relapses durings steroid therapy OR within 2 weeks of stopping therapy, relapses on maintenance therapy
36
What are the most common causes of CKD in children?
Renal dysplasia / Congenital structural disease
