Nephrology/Urology

Question 1

hypertension in children

Answer 1

• know your normal values
  
  • newborn average systolic BP 70-75
  • 1 year old average systolic BP 90
  • 5 year old average systolic BP 95
  • 12 year old average systolic BP 100-105
  • hypertension is BP >95^th percentile for age, gender & height
  • Severe hypertension is >95^th %-ile + 12mmHg (or 140/90)
• hypertension is more often secondary than primary (“essential”) in children
• consider renal disease, endocrine disease first
• early hypertension in children is a precursor to serious adult hypertension

Question 2

hypertension in children - differential diagnosis

Answer 2

• renal disease
  
  • pyelonephritis
  • renal parenchymal disease
  • congenital anomalies
  • reflux nephropathy
  • acute glomerulonephritis
  • Henoch-Schönlein purpura
  • renal trauma
  • hydronephrosis
  • hemolytic-uremic syndrome
  • renal stones
  • nephrotic syndrome
  • Wilms tumor
  • hypoplastic kidney
  • polycystic kidney disease
• endocrine
  
  • hyperthyroidism
  • congenital adrenal hyperplasia
  • Cushing syndrome
  • primary aldosteronism
  • primary hyperparathyroidism
  • diabetes mellitus
  • hypercalcemia
  • Pheochromocytoma
  • Adrenogenital syndrome
• neurologic
  
  • increased ICP
  • Guillain-Barre syndrome
• pyschologic causes
  
  • mental stress
  • anxiety
• vascular causes
  
  • renal artery abnormalities
  • renal vein thrombosis
  • coarctation of the aorta
  • patent ductus arteriosus
  • arteriovenous fistula
• drugs
  
  • anabolic steroids
  • corticosteroids, OCPs
  • PCP, cocaine
• other
  
  • pain
  • collagen vascular disease
  • neurofibromatosis

Question 3

evaluation of hypertension

Answer 3

• history
  
  • CNS - headache, seizures
  • hearing impairment
  • CV - palpitations
  • renal - edema, UTI, urine output
  • medications
  • neonatal history
    
    • history of central catheter
  • early CV disease
• cause
  
  • intracranial hypertension
  • Alport syndrome
  • catecholamine
  • nephropathy (HUS, SLE, GN, tumor, ADPKD, etc.)
  • OCPs
  • renal artery or aortic stenosis
  • obesity, essential hypertension
• Physical
  
  • Abdominal bruit
  • Diminished leg BP/pulse in
  • Café au lait spots
  • Abdominal mass
  • Opsoclonus myoclonus
  • Tachycardia/flushing
  • Striae, buffalo hump, acne
  • Early puberty
• cause
  
  • Renal vascular disease
  • Coarctation of the aorta
  • neurofibromatosis
  • Wilm’s Tumor
  • Neuroblastoma
  • pheochromocytoma
  • Cushing’s
  • Adrenogenital syndrome

Question 4

workup of HTN in children

Answer 4

• BP measurements with appropriate cuff size on different visits
• Work UP
  
  • Baseline etiology assessment- Urinalysis, Electrolytes, BUN, Cr, renal ultrasound
  • If Clinical Suspicion- plasma metanephrines , thyroid studies, vascular imaging (renal Doppler studies)
  • Target Organ- Echocardiogram
  • Cardiovascular Risk Factors- Lipids, Fasting Glucose, Uric Acid

Question 5

HTN tx in children

Answer 5

• treatable causes must first be ruled out
  
  • much more common to have a treatable cause in children than in adults
• exercise
• diet changes to address obesity and co-morbidities
• medical therapy
  
  • diuretics
  • ACE inhibitors
  • β-blockers
  • calcium channel blockers
• Hypertensive emergencies (encephalopathy, CHF with hypertension AND hypertensive urgency (Extreme elevations of BP without symptoms) require immediate management often require hospitalization.
• The chronicity of the process affects the rate that the BP is safely lowered.

Question 6

Hematuria

Answer 6

• red urine without urinalysis evidence of blood
  
  • red dye, food, medication or chemical excreted in urine
• red urine with urinalysis evidence of blood but no RBC on microscopy
  
  • free hemoglobin
    
    • hemolysis, DIC
  • free myoglobin
    
    • crush injury, burns, myositis, asphyxia
• red urine with urinalysis and microscopy evidence of blood but no RBC casts
  
  • bleeding from urinary tract distal to renal tubules
• red urine with blood and casts in urine
  
  • glomerular disease
    
    • immunologic disease (e.g., post-streptococcal glomerulonephritis)
    • inherited disease (e.g., Alport syndrome)
    • vascular injury (e.g., ATN, cortical necrosis, etc.)

Question 8

hematuria work-up

Answer 8

• history and physical exam
• confirm true hematuria
  
  • if microscopic with benign H&P => recheck
  • if repeatedly positive or positive H&P => workup

Question 9

hematuria ddx

Answer 9

• urinary tract infection/cystitis/urethritis
• hypercalciuria
• urolithiasis
• trauma
• post-streptococcal glomerulonephritis
• IgA nephropathy
• HSP (Henoch Schönlein purpura)
• systemic lupus erythematosus
• nephrotic syndrome (20% of cases also have hematuria)
• membranoproliferative glomerulonephritis
• Alport syndrome (sensorineural deafness, progressive renal failure)
• sickle cell trait/disease
• structural abnormality
• renal or urinary tract tumor
• benign
  
  • benign familial hematuria
  • post-exercise

Question 10

workup for hematuria

Answer 10

• Phase I
  
  • urinalysis with microscopic examination
  • CBC
  • urine culture
  • chem 8 (including BUN, Cr)
  • 24 hour urine collection for creatinine, protein, calcium
  • serum C3 level
  • renal ultrasound
• phase II
  
  • ANA titer
  • throat culture for Streptococcus pyogenes
  • ASO titer or DNAse B titer or streptozyme
  • urine erythrocyte morphology
  • coagulation studies
  • sickle cell screen
  • VCUG
• renal biopsy indicated for
  
  • persistent high grade microscopic hematuria
  • microscopic hematuria and
    
    • diminished renal function
    • proteinuria exceeding 150mg/24 hours
    • second episode of gross hematuria

Question 11

post-streptococcal glomerulonephritis

Answer 11

• clinical presentation: NephrITIC syndrome
  
  • 5-21 days (average 10) after streptococcal infection
  • gross hematuria (65% of cases)
  • edema (75% of cases)
  • hypertension (headache, visual changes) – 50% of cases
• laboratory
  
  • elevated ASO titer
  • group A beta-hemolytic streptococcal infection
  • decreased C3 level
• treatment
  
  • antibiotic for Streptococcus pyogenes
  • supportive care for renal function
    
    • reduce salt intake
    • treatment with diuretics
    • anti-hypertensive drugs

Question 12

IgA nephropathy

Answer 12

• pathogenesis
  
  • glomerulonephritis with IgA immunoglobulin in mesangial deposits
  • absence of systemic disease
• clinical manifestations
  
  • episode of gross hematuria 1-2 days after a viral upper respiratory infection
  • may be picked up by urinalysis showing microscopic hematuria
• treatment
  
  • usually resolves with minimal intervention in children
  • some progress to have
    
    • hypertension
    • diminished renal function
    • proteinuria
• 25% of adults progress to end-stage renal disease

Question 13

systemic lupus erythematosus

Answer 13

• clinical manifestations
• systemic symptoms
  
  • 1. malar rash
  • 2. discoid rash
  • 3. photosensitivity
  • 4. oral ulcers
  • 5. arthritis
  • 6. serositis
  • 7. renal disorder
  • 8. neurologic disorder
  • 9. hematologic disorder
  • 10. Immunologic
  • 11. positive ANA
• renal disease - variable
  
  • spectrum from minimal renal involvement to end-stage renal

Question 14

proteinuria

Answer 14

• normal children – spot protein to creatinine ratio <0.2
  
  • definition
  • urinary protein loss of 50mg/kg per 24 hours
  • may be result of normal activity
    
    • exercise
    • febrile illness
    • upright posture
  • Non-renal causes include
    
    • drug and heavy metal intoxication
    • processes that increase glomerular filtration
      
      • physical damage
      • abnormal hemodynamics

Question 15

nephrotic syndrome

Answer 15

• clinical diagnostic criteria
  
  • generalized edema
  • hypoproteinemia (<2.5 g/dL)
  • urinary protein/creatinine ratio > 2
  • hypercholesterolemia (>250 mg/dL)
• pathophysiology
  
  • loss of basement membrane sialoproteins
    
    • loss of normal negative charge
  • allows glomerular permeability to proteins
  • protein loss in urine
    
    • hypoalbuminemia
    • loss of plasma oncotic pressure – fluid shifts from vascular to interstitial compartment
    • increases risk of thromboembolism
    • hepatic lipoprotein synthesis stimulated by hypoproteinemia
• most often presents with sudden onset of pitting edema, weight gain or ascites
• differential diagnosis
  
  • transient proteinuria (with fever, dehydration, etc.)
    
    • protein to creatinine ratio reveals mild proteinuria, ratio <1
  • postural (orthostatic) proteinuria
    
    • benign condition of moderate proteinuria while upright
    • rationale for 1^st morning samples
  • glomerular proteinuria
    
    • associated with acute illnesses involving kidney
  • minimal change disease (typical nephrotic syndrome)
  • congenital nephrotic syndrome
  • focal segmental glomerulosclerosis
  • mesangial nephropathy
  • membranous nephropathy
• epidemiology
  
  • onset < 6 years of age
• clinical findings
  
  • edema
  • periorbital swelling
  • oliguria
  • fluid shifts
    
    • ascites
    • pleural effusion
    • scrotal/labial edema
• laboratory
  
  • low albumin
  • urinalysis (proteinuria)
    
    • 1+ or greater proteinuria on 2 or more random specimens warrants quantitative measure or proteinuria
      
      • first a.m. void spot protein/Cr ratio
      • ratio >0.5 prompts lab and radiographic workup
    • C3 level
      
      • a low C3 level is the most sensitive & specific test to imply a presence OTHER than minimal change disease
    • renal biopsy
      
      • generally unremarkable
      • foot processes of glomerular basement membrane fused
• treatment
  
  • corticosteroids
    
    • 80% of patients respond
  • low sodium diet to prevent massive fluid shifts
  • if steroid not working, may try immunosuppressive agents
  • renal biopsy if no response after steroids and immunosuppressive agents
    
    • biopsy would typically precede steroids if C3 level was low (implying disease other than minimal change disease)
• complications
  
  • infection
    
    • peritonitis
    • bacteremia/sepsis
      
      • S. pneumoniae
      • E. coli
    • cellulitis
  • hypercoagulability
  • pleural effusion
  • renal insufficiency - blood pressure instability

Question 16

urinary tract abnormalities

Answer 16

• 3-4% of all infants have some urinary tract abnormality
• unilateral renal agenesis is present in 1:2900 births
• ADPKD (1:1000) and ARPKD (1:10k-40k)
  
  • ADPKD can present in infancy and childhood
• urinary tract obstruction is an important cause of nephropathy
  
  • ureteropelvic junction (UPJ) obstruction
  • posterior urethral valves (1:50,000 boys)
    
    • poor urine stream
    • UTI more common due to stasis of urine
    • urethra dilates, VUR may develop, kidneys swell and become dysplastic
    • rupture of the renal pelvis may cause urinary ascites
      
      • most common cause of newborn ascites
    • hopefully caught on fetal ultrasound (as urinary obstruction)
    • Renal ultrasound indicated if UTI occurs < age 2.

Question 17

penile disorders

Answer 17

• hypospadias – ventral malposition of urethral meatus
  
  • 1 in 500 newborn boys
  • severe cases prompt suspicion of congenital adrenal hyperplasia and masculinization of female genotype
  • often associated with chordee (ventral curve in penile shaft)
  • testes undescended in 10% of boys with hypospadias
• phimosis – unretractable foreskin
  
  • 90% of boys can retract foreskin by age 16
  • remaining 10% have phimosis
  • treated with serial stretching or steroid cream
  • circumcision in severe cases
• paraphimosis – trapped retracted foreskin
  
  • trapping of retracted tight foreskin in coronal sulcus
  • foreskin becomes swollen, red and *extremely* painful
  • reduced manually with lubrication and plenty of analgesia
  • rarely proceeds to circumcision

Question 18

acute scrotum

Answer 18

• testicular torsion
• torsion of the epididymal appendix (appendix testis)
• epididymitis

Question 19

testicular torsion

Answer 19

• torsion of the testis twists the spermatic cord, causing vascular compromise of involved testicle
• acute onset of severe scrotal and testicular pain
  
  • May be reported as abdominal pain.
• nausea
• vomiting
• swelling and color change of scrotum
• transverse lie of testicle
• Absent cremasteric reflex
• vascular flow absent in scrotal ultrasound
• 90% of testes addressed in the first 6 hours of symptoms survive
• surgical
  
  • detorsion
  • orchiopexy

Question 20

torsion of the appendix testis

Answer 20

• appendix of the epididymis may torse and undergo vascular compromise
• signs & symptoms
  
  • more insidious onset of pain compared to testicular torsion
  • nausea, vomiting
  • “blue dot” sign- pain at upper pole of testicle with appearance of blue dot
  • point tenderness at epididymis
  • minimal swelling
  • torsion of testis needs to be ruled out if pain is moderate or severe

Question 21

epididymitis

Answer 21

• inflammation of the epididymis usually secondary to infection or inciting agent
  
  • sexually transmitted infection
  • urinary tract infection/structural anomaly
  • trauma
  • chemical inflammation
  • often with antecedent sexual activity or UTI
• clinical presentation
  
  • pain and swelling of the epididymis
  • frequency, dysuria, urethral discharge
  • fever
• physical exam
  
  • normal vertical lie of testis
  • normal cremasteric reflex
  • scrotal edema, redness
• laboratory
  
  • urinalysis, urine culture
  • urine nucleic acids for N. gonorrhoeae, C. trachomatis
  • Gram stain and culture of urethral discharge
  • consider screening for other UTIs in high risk patients
• treatment
  
  • antibiotics to address UTI or sexually transmitted disease
  • further work up if age or circumstances suggest a structural anomaly
    
    • scrotal or renal ultrasound
    • VCUG

Question 22

hydrocele

Answer 22

• trapped fluid around the testis located in the tunica vaginalis
• two types
  
  • communicating
    
    • precursor to inguinal hernia
  • non-communicating
• treatment
  
  • observation - first two years of life
  • earlier if
    
    • underlying problem (adjacent testis becomes inflamed)
    • not resolving
    • compromise to the testicle

Question 23

undescended testes (cryptorchidism)

Answer 23

• Present in 3.4% of newborn boys
• Remain in 0.7% at 1 year of age
• More common in infants born premature
• If no descent by age 1 year, testes are located (if present) and surgically corrected (orchidopexy) or removed
• Need to be distinguished from retractile testes
  
  • retract from scrotum when cold
  • present in scrotum by parent’s report
• Testes retained in the abdomen are at higher risk for progression to testicular cancer
  
  • infertility rates are higher for patients with even one undescended testis
  • rates of torsion also higher in undescended testis