Nephrology / Urology Flashcards
What is the typical age of onset for post-strep glomerulonephritis?
5-12-years old (rare <3yo)
What are reasons to consider a renal biopsy in PSGN to look for an alternative diagnosis?
- 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
What are the 4 most common causes if high grade congenital hydronephrosis?
- 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
What is the most common enzyme defect in CAH?
21-hydroxylase (enzyme) deficiency (95% of cases)
What is the differential diagnosis for acute glomerulonephritis and decreased serum complement levels (C3, C50)?
- Systemic diseases: Lupus nephritis, subacute endocarditis, shunt nephritis, essential mixed cryoglobulinemia, visceral abscess
- Renal disease: acute PSGN, membranoproliferative GN Type 1
What is the differential diagnosis for acute glomerulonephritis and normal serum complement levels (C3, C50)?
- 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)
What is the treatment for post-strep glomerulonephritis?
- 10 day course of Penicillin (does not alter course but limits spread)
- Sodium restriction
- Diuresis with IV lasix
- HTN - Ca channel blockers, vasodilators, ACEi
What is the recommended investigations for a child with confirmed hypertension?
- 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)
What is the recommended investigations for a child with confirmed hypertension?
- 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)
What are factors that suggested a diagnosis OTHER than idiopathic MCNS in nephrotic syndrome?
- 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
What is the treatment for typical nephrotic syndrome?
Steroids 2mg/kg (max 60mg) PO x6wk with a 4wk taper
NS & Fluid restriction
What are the complications of nephrotic syndrome?
- 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
What are the 4 most common causes of high grade congenital hydronephrosis?
- UPJO
- High grade VUR
- UVJO
- PUV
What is the most reliable imaging test to detect nephrolithiasis
Most reliable: CT KUB (but this is second line)
1st line: renal ultrasound (may miss small ureteric stones)
What are the most likely pathologies to cause AKI in children?
- Pre-renal AKI (especially due to hypovolemia)
- HUS (R/O early)
- ATN (usually post-hypotensive episode in OR, MVA)
- PSGN
- SLE PMGN
- HSP
What are the atypical features for nephrotic syndrome?
- Age < 1yo
- Persistent HTN (BP > 95th %)
- Persistently decreased renal function (eGFR < 90)
- Significant or gross hematuria (>50 RBCs/HPF)
- Steroid resistant NS
What is the definition of steroid resistant in nephrotic syndrome? What are the different types of non minimal change NS?
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
What is the formula for calculating free water deficit?
Free water deficit = total body water (TBW) x ([current plasma Na+/140] - 1)
What are the potential complications of PSGN?
- 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)
What are features that can be used to differentiate testicular torsion from torsion of the testicular appendix?
- 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
What are the definitions of pre-HTN, Stage HTN?
- 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 %
What are the pediatric populations at greater risk of hypertension? How often should children + children with RFs be screened?
- 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
What is the work-up for confirmed hypertension?
- 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)
What are risks associated with having a horseshoe kidney?
- 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
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
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
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
What are the indications for doing a VCUG?
- SFU III-IV CH
- 2nd febrile UTI work-up (also consider if poor growth, hypertension, atypical organism)
- Suspicion of PUV
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
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
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
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
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
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
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
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
What findings on a screening AUS would prompt ordering a VCUG?
- Hydronephrosis, hydroureter
- Small kidneys
- Thick walled bladder
- Renal parenchyma abnormal - scars, cysts
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
What are the most common causes of CKD in children?
Renal dysplasia / Congenital structural disease
