Flashcards in Nephrology q-bank Deck (67):
What is the definition of hypertension?
A systolic +/- diastolic blood pressure that is >/= 95% for age, sex and height on >3 occasions.
Difference between primary and secondary hypertension? Causes?
Primary- no known cause, most adults.
Secondary- secondary to other issue, in kids 90% is secondary to renovascular hypertension and renal issues (chronic GN, reflux or obstructive nephropathy, HUS, polycystic or dysplastic renal disease)
Explain the evaluation for a child with hypertension
History and physical :)
*sleep, FamHx, RFs (diet, habits)
urinanalysis, urine culture
BUN, creat, electrolytes
Other investigations to perform if confirmed hypertension?
(as per Nelson's)
Echocardiogram (evaluate for LVH etc..)
Retinal exam (retinal vascular changes)
What kind of stones should you think of associated with a gram negative rod UTI?
(magnesium ammonium PO4)
What is the most common palpable abdominal mass in a newborn?
A hydronephrotic kidney is most common,
then a multicystic kidney
What is the best test to evaluate vesicoureteral reflux in kids with hydronephrosis?
What is the best test to evaluate if renal scarring in present in a kid with posterior urethral valves?
(nuclear renal scan)
What should you suspect with a flank mass, hematuria and thrombocytopenia?
Renal vein thrombosis
What are risk factors for renal vein thrombosis?
older kids (4)
cyanotic heart disease
Hyperchloremia, hypokalemia, chronic non-AG metabolic acidosis and hypercalciuria are features of what?
Distal Renal Tubular Acidosis (type 1)
- impaired hydrogen ion secretion distally
- urine pH >5.5 (N 6.5-8) + urine AG
- non-anion gap metabolic acidosis
Chronic non-AG metabolic acidosis, acidic urine and hypokalemia are features of what?
Proximal Renal Tubular Acidosis (type 2)
-impaired bicarbonate reabsorption proximally
- urine pH >5.5 initially then <5.5 + urine AG
- usually a part of Fanconi syndrome (proteinuria, glucosuria, phosphaturia & prox RTA)
Hyperkalemia, non-AG metabolic acidosis are features of what?
Renal tubular Acidosis type 4, aldosterone deficiency or resistance
-urine pH <5.5 + urine AG
Urine anion gap suggests what?
Renal tubular acidosis!
Urine pH >5.5 suggests what?
or RTA2 early on
What is the best single antibody titer to document previous streptococcal infection?
anti-DNAse B level
Indications for renal biopsy in post-streptococcal GN?
- if hematuria, proteinuria, low C3 or diminished renal function persist for >2 months
- acute renal failure
Management of post-streptococcal GN?
treating acute effects and preventing spread
-10 days antibiotics
-diuresis, initially furosemide
-hypertension txt with CCB, ACE-i, vasodilators
What types of glomerulonephritis present with low C3?
Post-streptococcal (+antiDNAseB Ab)
Lupus (+anti-DNA Ab)
What types of glomerulonephritis present with anti-GBM autoantibodies?
Goodpastures's syndrome (lung hemorrhage)
What types of glomerulonephritis present with anti-neutrophil cytoplasmic antibodies? (ANCA)
Eosinophilic polyangiitis (asthma, allergies)
Microscopic polyangiitis (systemic necrotizing arteritis)
Wegener's Granulomatosis with polyangiitis (cANCA +anti-PR3)
What test can help you distinguish between acute kidney disease and chronic kidney disease?
large in acute
small in chronic
What conditions are associate with Fanconi syndrome?
Glycogen storage disease type 1
Dent's, Lowe, GRACILE, Fanconi-Bickel...
What does hypokalemia, alkalosis, hyperaldosteronism, hypercalciuria, salt wasting fit with?
Excessive Lasix ingestion or Barter's!
presents early in life, polyhydramnios
What does hypokalemia, alkalosis, hypomagnesemia, hypocalciuria, salt wasting look like?
Excessive Hydrochlorothiazide ingestion or Gitelman's!
What is the triad of HUS?
Name an infectious and genetic etiology.
MAHA, thrombocytopenia, renal insufficiency
E. coli 0157H7
A boy with a hearing impairment and microscopic hematuria exacerbated within 1-2 days of URTI (or proteinuria or nephrotic syndrome) most likely has what?
type IV collagen gene mutation
they also have anterior lenticonus
Name two severe complications of PSGN
encephalopathy secondary to uncontrolled hypertension
heart failure secondary to hypertension and hypervolemia
Approach to asymptomatic microscopic hematuria?
Repeat u/a weekly x2, no exercise before
If persists, urine culture
If persists, then urine spot calcium:creatinine ratio + Hgb electrophoresis if black
IF hx & p/e remain normal, can follow for 1 year before:
-test parent's urine
-serum creatinine and electrolytes
-refer to Nephrologist
What is the management of simple renal cysts?
Complex renal cysts?
Follow up simple renal cysts.
Complex renal cysts need additional work-up because of their higher likelihood of malignancy. CT or MRI, then consider surgery.
What is the earliest that you should perform an US to evaluate antenatal VUR?`
fluid shifts occurring postnatally may artificially underestimate the degree of VUR
How do you manage a post-natal confirmation of bilateral VUR grade 4-5?
Order VCUG with antibiotic prophylaxis until testing.
IF confirmed VUR IV-V (or positive reflux acc to Nelson's), continue abx prophylaxis and order functional renal scan.
IF VUR 1-III, no abx and F/up US q3months
What antibiotics are recommended for prophylaxis in VUR?
Amoxil for first month of life (Hamilton)
Septra or Nitrofurantoin thereafter
1/3-1/4 of normal daily dose
Aim for only 3-6 months
What are dynamic radionuclear scans and what are they used for?
MAG-3 or DTPA
used to evaluate renal function and to diagnose urinary tract obstruction in infants with hydronephrosis
What is seen in nephrotic syndrome?
Proteinuria (>3.5g/day), edema, hypoalbuminemia
Increased susceptibility to infections
*note urine loss of Ig's and complement make more susceptible to infection, loss of coagulation factors
Recurrent hematuria around URTIs and within 1-2 days of symptom onset is suggestive of what?
What is the most common chronic glomerular disease?
How to diagnose?
What is seen?
- IgA nephropathy
- diagnose with biopsy
- predominance of IgA immunoglobulin with mesangial glomerular deposits in the absence of systemic disease
Name 5 common causes of gross hematuria
What measurement distinguishes mild to moderate hydronephrosis from severe?
What tests can be used to distinguish between pre-renal and intrinsic acute kidney injury?
Fractional excretion of sodium:
(UNa/SeNa) / (UCr/SeCr) = %
FeNa <1%= prerenal, almost all filtered sodium is reabsorbed, which is a natural response to decreased perfusion
FeNa > 2%= ATN, kidneys are failing to handle properly
>20 = prerenal AKI , BUN avidly reabsorbed in PT but this test isn't reliable because of known alternative causes that elevate BUN like TPN, catabolism, GI bleeding
How do you calculate an anion gap?
What is the normal value?
Na - (Cl + HCO3)
12 +/-4 meq/L
What organ systems are affected in Cystinosis?
Describe the findings in infantile cystinosis?
aka Nephropathic cystinosis
-present in first 2 yrs with severe tubular dysfxn and growth failure
-ESRD by end of 1st decade of life
-Fanconi syndrome with polyuria, polydipsia, FTT, rickets
-fair skinned and blond
-can also develop hypotTh, HSM, delayed sexual maturation
How to diagnose cystinosis?
Cystine crystals in the cornea
Measurement of increased leukocyte cystine content
Prenatal testing available
Treatment with cysteamine, converts to cysteine facilitating lysosomal transport and decreasing tissue concentrations
What is the triad associated with Prune Belly Syndrome?
Abdominal muscle deficiency
Severe urinary tract abnormalities
Bilateral cryptorchidism in males
30% of survivors develop ESRD
What electrolyte concentrations are suggested for ORT solutions?
Na -Cl: 45-60mmol/L
What % of dehydration is associated with mild, moderate and severe? What is the recommended volume of ORT?
Mild: <5% ; 50mL/kg over 4 hrs
Moderate: 5-10%; 100mL/kg over 4 hrs
Severe: >10%; IV 20-40mL/kg NS or RL over 1hr
Always replace ongoing losses, age appropriate diet after rehydration.
What lab anormalities are associated with hypernatremia?
What is the maximum rate of correction for hypernatremia?
-max 12meq/L in 24hrs, unless symptomatic
Prerenal or AKI?
ATN or hypovolemia?
When to refer an undescended testes?
It won't spontaneously descend after 4 months, surgery should be performed no later than 15 months.
What are consequences of cryptorchidism?
testicular malignancy - pathologic changes by 6-12mo!
torsion of the high testis
psychological effects of empty scrotum
Does the risk of germ cell malignancy go down after orchidopexy?
The jury is out!
While riding high the risk is 2-4x higher than the general population (1/80 with unilat, 1/40-50 with bilat)
Early descent is associated with better outcomes (<2yo)
Which primary kidney disorders are classically associated with hypertension?
Autosomal recessive polycystic kidney disease (ARPKD)
Autosomal dominant PKD (ADPKD)
List causes of elevated anion gap metabolic acidosis
Methanol, Uremia, DKA, Paraldehyde/Propylene glycol, Iron/INH, Lactate, Ethanol, Salicylates
A seizing hyponatremic patient, how to manage?
Hypertonic saline 3% 4-6mL/kg
Describe hypernatremic dehydration approach to IVF
1) Maintenance fluids (4-2-1 rule)
2) Free water deficit correction = .6 x kg x ((SeNa/140)-1)
which can be given with 0.45NS (ie: NS=N, D5W not good to infuse, meet halfway with 0.45NS so giving 1/2 free water, therefore need 2x as much)
3) replace ongoing losses 1:1
Follow electrolytes closely, min q6hrs
How to diagnose hypercalciuria?
Best: 24hr urine calcium excretion >4mg/kg
Screening test: random urine calcium to creatinine ratio, >0.2 suggests hypercalciuria in an older child
How to diagnose nephrolithiasis?
Plain x-ray and ultrasound to start
Weigh risks and benefits of CT (the gold standard) but ++ radiation
What can cause transient proteinuria?
What is the most common cause of persistent proteinuria in school-aged children and adolescents?
How to confirm?
First morning urine sample x3
If no protein seen or UrineProtein:UrineCreatinine ration <0.2, diagnosis is confirmed.
When should inguinal hernias be repaired in the following groups?
<1yr: repair quickly! High likelihood of incarceration before 11 months (70%!)
NICU: before discharge from unit
What is your differential diagnosis for a neonate with hyponatremia and hyperkalemia?
Defects in aldosterone production or function
Adrenal damage or dysfxn (hemorrhage, absence, infection, insufficiency)
Type IV RTA
Defects in cholesterol biochemistry
What urine specific gravity do you see in dehydration? In a fluid replete individual?
Urine >1.03 is concentrated
Urine <1.01 is dilute
Give an example of a calcium channel blocker & its side effect
Give an example of a beta blocker & its side effect
very short acting so constant infusion preferred,
may cause bradycardia