Nephrology Flashcards
What is the most common cause of severe obstructive uropathy in Prune-Belly Syndrome?
Posterior urethral valves
What are the electrolyte changes seen in cystinosis?
Pure proximal tubular disorder
- Losses of sodium, potassium, citrate, bicarb, phosphate, vitamin D, copper and carnitine
What clinical features are seen in cystinosis?
- Presents usually in first 6 months of life
- Renal findings first
- Eye findings (cysteine crystal deposition)
- Bones become infiltrated with cysteine crystal laden granulomas - fractures, rickets, bony pain, genu valgus
- Chiari 1 malformation
- Premature skin aging
What is the gold standard for confirming cystinosis?
HPLC mass spec forleucocyte cystine content
Can also do genetic screen for mutations in CTNS gene
What treatment is available for children with cystinosis?
Supportive measures:
○ Substitution of urinary lost compounds
○ Nutritional support - prevention of rickets and improvement of growth
§ Free access to water, Na, K, citrate or bicarb, P, vitamin D, Cu, Carnitine
§ goal: 130% of recommended daily intake
○ Hormonal replacement therapy
§ Growth hormone
§ Levothyroxine for hypothyroidism
§ Insulin
○ ACE-i for proteinuria
Treatment: Cystine-depleting therapy by use of cysteamine (PO or topical)
What is the most common manifestation of end-organ damage as a result of hypertension?
LVH
Will also likely see increased carotid intima-media thickness, hypertensive retinopathy, microalbuminuria
What are some common renovascular causes of hypertension in children?
- Fibromuscular dysplasia
- Syndromic → NFI, TS, Williams syndrome, Marfan syndrome
- Vasculitis → Takayasu disease, Polyarteritis nodosa, Kawasaki disease
- Other → radiation therapy, UAC, trauma, congenital rubella syndrome, transplant renal artery stenosis
How do you ensure an accurate BP measurement?
- Appropriate size cuff has bladder that take up 40% of arm circumference and should cover ⅔ of upper arm length and 80-100% of its circumference
- Child should be seated, quiet and in no distress
What is the diagnostic criteria for hypertension in a child?
SBP and / or DBP ≥ 95th percentile for age, sex, and height on ≥ 3 occasions
For children aged 1-13 y
- Normal BP: <90th percentile
- Elevated BP: ≥90th percentile to <95th percentile or 120/80 mm Hg to <95th percentile (whichever is lower)
- Stage 1 HTN: ≥95th percentile to <95th percentile +12 or 130/80 to 139/89 mm Hg (whichever is lower)
- Stage 2 HTN: ≥95th percentile +12 or 140/90 (whichever is lower)
For children aged ≥13 y
- Normal BP: <120/<80 mm Hg
- Elevated BP: 120/<80 to 129/<80 mm Hg
- Stage 1 HTN: 130/80 to 139/89 mm Hg
- Stage 2 HTN: ≥140/90 mm Hg
How often should BP be checked in children?
• At least once a year in all children 3 or older
• At every health visit if the child has known or suspected diabetes, renovascular disease, CKD, or a predisposing condition linked to HTN
- in some cases, this may also involve checking for ketones and/or proteinuria
Can children with hypertension take part in competitive sports?
Children and adolescents with HTN may participate in competitive sports once hypertensive target organ effects and cardiovascular risk have been assessed
Children and adolescents with HTN should receive treatment to lower BP below stage 2 thresholds before participation in competitive sports
What tests should be done to assess renal function in the case of hypertension?
- For all children with hypertension:
• Blood chemistry (sodium, potassium, chloride, total CO2, and creatinine)
• Urinalysis
• Renal ultrasound - For children with HTN who need evaluation of cardiovascular risk:
• Fasting blood glucose
• Serum total cholesterol and high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triglycerides - For children with HTN who need assessment for target organ damage:
• Echocardiogram
• Retinal examination
• Albumin/creatinine ratio (first morning)
What are the clinical features of Denys-Drash syndrome?
- Risk of developing Wilm’s tumours
- Early-onset nephrotic syndrome
- Progressive renal insufficiency
- Ambiguous genitalia
In what conditions would you expect a decreased C3 level?
“MAPLES”
Membranoproliferative glomerularnephritis
Atypical HUS
Post-infectious glomerulonephritis (No. 1 most common)
Lupus
Endocarditis
Shunt nephritis
What are the 4 hallmark clinical findings of Henoch Schonlein Purpura?
Small vessel vasculitis, characterized by IgA deposition and leukocytoclastic vasculitis
1) Palpable purpuric rash
2) Joint pain
3) Renal disease (proteinuria/hematuria)
4) GI involvement
How long should you be monitoring a child with HSP for renal complications?
Throughout illness and up to 1-2 months afterwards: BP and urinalysis q weekly
Up to 6-12 months post recovery: q monthly
What treatment do you offer for children with HSP?
Mostly supportive management - may consider prednisone (short course, 1-2 mg/kg/day) in those with severe GI disease
What are some potential surgical complications of HSP?
- Intussusception
- Mesenteric ischemia
- Intestinal perforation
- Orchitis
- Testicular torsion
- Pulmonary hemorrhage
What is the definition of nephrotic range proteinuria?
• Proteinuria
○ > 40 mg protein/m2/hr or >1000mg/m2/day
○ >3+ protein on dipstick
○ >3-3.5 g in a 24 hr urine sample
○ >2.5-3 urine protein to creatinine ratio in a random sample
Nephrotic syndrome patients will also have:
• Hyperlipidemia cholesterol >200 mg/dL
• Edema
• Hypoalbuminemia ≤2.5 g/dL
What is orthostatic proteinuria?
- Increased urinary protein excretion during the day in tall, active, slender adolescents, which usually resolves when first morning sample is collected (disappears with supine position after at least 2 hours)
- Accounts for 60% of proteinuria in adolescents
- Benign condition
- Should be tested for proteinuria on a yearly basis
• If protein-creatinine ratio is >0.2 in a first morning urine, it is abnormal and indicates renal pathology
What are some benign causes for proteinuria?
- Febrile illness
- Seizures
- Extreme cold
- Stress
- Epinephrine administration
- CHF
- Abdominal surgery
- Strenuous exercise