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Board Review nephrology


BOARD REVIEW NEPHROLOGY Karen Estrella-Ramadan Case A 4mo M infant presents with a hx of poor wt gain and irritability. FT, NSVD, Bwt:3.5kg. He was BF for 3 months ... – PowerPoint PPT presentation

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Title: Board Review nephrology

Board Review nephrology
  • Karen Estrella-Ramadan

Question 1
  • You are seeing a 10-year-old girl who has SLE for
    a WCC. You diagnosed SLE when she was 8y/o, based
    on an initial presentation of idiopathic
    thrombocytopenic purpura and a positive ANA test
    and the subsequent development of arthritis and a
    positive anti-double-stranded DNA test. She is
    currently doing well in school and has no
    concerns about her memory or problem-solving
    skills. The only finding of note on her physical
    examination is a slight erythematous rash in a
    malar distribution.
  • Of the following, the MOST useful screening test
    for other organ involvement in this girl is

Of the following, the MOST useful screening test
for other organ involvement in this girl is
  1. Coombs test
  2. erythrocyte sedimentation rate
  3. magnetic resonance imaging of the brain
  4. Urinalysis
  5. Venereal Disease Research Laboratory (VDRL)

SLE patients have high mortality from Renal and
CNS disease
  • Renal do a U/A to screen , initially may be
  • Renal disease occurs in 75 to 80 of children
    who have SLE, usually within 2 years of
    diagnosis. Renal manifestations are not typically
    apparent at diagnosis most patients present with
    fever, rash, arthritis, and mucositis
  • Typical screening besides U/A, include urine
    protein-to-creatinine ratio, and serum creatinine
    and albumin.
  • Renal manifestations can range from asymptomatic
    hematuria and proteinuria to overt nephritis
    (gross hematuria, azotemia, and hypertension),
    nephrotic syndrome, or hypertension.
  • Patients in whom proteinuria (gt1 on a dipstick
    or urine protein-to-creatinine ratio gt0.2
    mg/mg) is discovered need Renal referral for
    assessment and possible renal biopsy.
  • CNS MRI if pt develops seizures, psychosis,
    headaches, difficulty with concentration, or
    memory problems.
  • Other organs
  • Hem hemolytic anemia? pallor, do Coombs
  • ESR non specific VDRL false positive

Question 2
  • An 8-year-old boy presents with cola-colored
    urine without blood clots. He was well until 2
    days ago, when he developed a sore throat with
    upper respiratory tract infection symptoms. He
    denies any dysuria, frequency, urgency, flank
    pain, or trauma. On physical examination, his
    temperature is 37.8C, heart rate is 84
    beats/min, respiratory rate is 18 breaths/min,
    and blood pressure is 118/78 mm Hg. He has no
    costovertebral tenderness, abdominal tenderness,
    or edema.
  • Labs show
  • Urine Specific gravity, 1.025, pH, 6.0, 3
    blood, 3 protein, 1 leukocyte esterase,
    Nitrite, negative
  • Microscopy shows more than 100 RBC/hpf and 5-10
  • BUN 24 mg/dL (8.6 mmol/L)
  • Creatinine, 0.9 mg/dL (79.6 mcmol/L)
  • C3 140 mg/dL (normal, 80 to 200 mg/dL)
  • C4 30 mg/dL (normal, 16 to 40 mg/dL)
  • ANA negative

Of the following, the most likely diagnosis is
  1. acute pyelonephritis
  2. immunoglobulin A glomerulonephritis
  3. postinfectious glomerulonephritis
  4. Urolithiasis
  5. viral cystitis

Dx acute glomerulonephritis?cola-colored urine,
hematuria/proteinuria, and mild azotemia
  • Things to differentiate
  • Urine color
  • bright red Lower tract bleeding? viral
    hemorrhagic cystitis or stones often accompanied
    by clots.
  • Cola-colored urine without clots ?glomerular
  • Yellow but on UA dipstick RBC, do a UA and
    likely for myoglobin,
  • Time
  • Very recent URI of but not specific for
    immunoglobulin A (IgA) glomerulonephritis.
  • 7-21 days later PSGN

  • Piuria gt 10WBC/hpf
  • Hematuria gt3 RBC/hpf in2 centrifugated samples
    of fresh urine
  • Proteinuria gt3.5 gr/day

Evaluation of a child with suspected AGN
  • Follow up Blood pressure and creatinine levels
  • If HTN, or rising creatinine levels ? renal bx
  • Follow serologic markers C3 and C4, ANA and
  • The combination of a normocomplementemic GN and a
    synpharyngitic pattern IgA nephropathy
  • Can also present with asymptomatic hematuria or
    hematuria/proteinuria. Patients who have gross
    hematuria have a better prognosis.
  • Treatment usually consists of steroids, ACE
  • Alternative diagnostic include
  • Alport renal, sensorineural hearing loss, ocular
  • Membranoproliferative glomerulonephritis low C3
    low C4
  • PIAGN strep infection, low C3, normal C4
  • Focal glomerulonephritis (HIV) normal complement

Question 3
  • A 17-year-old sexually active girl presents for a
    follow-up evaluation after her third episode of a
    urinary tract infection. She is currently
    asymptomatic. The results of renal
    ultrasonography and voiding cystourethrography
    are negative. She asks you how to prevent further

Of the following, you are MOST likely to advise
her to
  1. drink cranberry juice frequently
  2. increase her daily water intake
  3. make sure to void after intercourse
  4. self-medicate with antibiotics for 3 days when
  5. use single-dose postcoital antibiotic prophylaxis

She hasacute cystitis
  • gt common in girls, gt 3 UTI in a yr
  • Best preventive measure ( even after 5y of use)
  • symptoms with sexual intercourse? postcoital
    antibiotic prophylaxis (taken within 2 hours of
  • nitrofurantoin 50 mg, TMP-SMX 40/200 mg, or
    cephalexin 500 mg
  • Those who fail, UTI not associated with a
    modifiable cause or at risk of complicated UTI
    give continuous
  • TMP-SMX (40/200 mg daily at bedtime or 3 times
    per week)
  • nitrofurantoin (50 to 100 mg daily at bedtime or
    3 times per week),
  • norfloxacin (200 mg daily at bedtime or 3 times
    per week)
  • and cephalexin (250 mg daily).
  • Stop meds after 6-12 months trial, if fails,
    restart abx
  • Self-medication when symptomatic with a 3-day
    regimen is another option
  • Women with one to two UTI per year).
  • IF UTI after sexually active no imaging
  • Behavior changes proper wiping, avoid tight
    pants, avoid urge-initiated voiding, postcoital
    voiding, increased fluid intake, and the daily
    consumption of cranberry juice

Question 4
  • You are examining a newborn who has wrinkling of
    the abdominal wall skin. His mother recalls her
    obstetrician mentioning that her fluid was low.
    The infant was born at 37 weeks gestation, and
    his birthweight was appropriate for gestational

Of the following, the MOST likely additional
findings expected in this infant are
cryptorchidism and
  1. bilateral hydronephrosis
  2. Hypospadias
  3. Nephrocalcinosis
  4. polycystic kidney disease
  5. unilateral renal agenesis

BL hydroureteral nephrosis absence of
abdominal wall musculature undescended testicle
prune-belly syndrome
  • PBS ? obstructive uropathy
  • Associated with renal dysplasia BUT NOT renal
    agenesis, nephrocalcinosis, cystic renal disease,
  • almost exclusively in males
  • 30 of affected patients eventually develop
    end-stage renal disease


Question 5
  • A 6y/o girl presents for a WCC that was scheduled
    as a follow-up appointment after she had an
    elevated blood pressure at an urgent care
    facility during an evaluation for abdominal pain.
    Her abdominal pain has resolved. Her mother
    recalls the blood pressure in the urgent care
    center as 135/90 mm Hg. The girl has had 2 UTI
    with fever in the past, and her father had
    hypertension diagnosed at age 45 years.
  • On physical examination, the girls temperature
    is 37.3C, heart rate is 90 beats/min,
    respiratory rate is 20 breaths/min, and blood
    pressure is 146/86 mm Hg. A repeat blood pressure
    reading is 142/88 mm Hg. The four limb blood
    pressures are 142/88 mm Hg in the right arm,
    144/84 mm Hg in the left arm, 156/100 mm Hg in
    the right leg, and 160/96 mm Hg in the left leg.
    You find no cardiac murmurs, abdominal bruits, or
    edema. Femoral pulses are 2 and symmetrical
  • Renal ultrasonography shows the left kidney to be
    8.5 cm with normal corticomedullary
    differentiation and the right kidney to be 5.5 cm
    with increased echogenicity.

Of the following, the MOST likely cause for this
patients elevated blood pressure is
  1. coarctation of the aorta
  2. essential hypertension
  3. renal artery stenosis
  4. renal hypoplasia/dysplasia
  5. renal scarring from prior pyelonephritis

  • HTN, hx of UTIs and US findings (increased
    ecogenicity)? renal scaring from pyelonephritis
  • ()VUR HTN in 20 of pts
  • Up to 8 yrs to develop
  • ()HTN 30-40 had scarring Hypertension can
    occur in up to 20 of patients who have ()VUR
  • Patients usually respond well to ACEIs
  • caution in female patients of childbearing age
    due to risks of teratogenicity.
  • If BL stenosis or on monorenal ptDONT USE
    ACEIs? will worsen renal failure due to
    inhibition contraction of efferent arteriole that
    will maintain glomerular filtration

Why not?
  • Coartation of the aorta femoral pulses are
    present and blood pressures are higher in the
    legs than in the arms
  • Essential HTN is a diagnosis of exclusion? mild
    hypertension in adolescent patients who are
    overweight and have a positive family history of
  • Renal artery stenosis is rare, associated with
    abdominal bruits on examination and a small
    kidney on ultrasonography.
  • Renal hypoplasia/dysplasia can be associated with
    an isolated small kidney, BUT hypertension is
    uncommon in this setting.

(No Transcript)
Question 6
  • You are called to attend the delivery of a
    newborn male who had been monitored carefully
    prenatally for moderate oligohydramnios. Prenatal
    ultrasonography suggested bilateral cystic
    dysplastic kidneys, with no other congenital
    anomalies identified.

Of the following, the MOST likely immediate
life-threatening problem in this infant is
  1. bladder outlet obstruction
  2. cardiac arrhythmias
  3. liver failure
  4. renal failure
  5. respiratory failure

  • The most immediate? possibility of respiratory
    failure from pulmonary hypoplasia.
  • due to decreased amniotic fluid volume, which may
    lead to reduced fetal respiratory excursion which
    impedes pulmonary development.
  • Potter sequence (oligohydramnios with pulmonary
    hypoplasia, clubfeet, and flattened facies)

Question 7
  • A 1-year-old girl presents for a health
    supervision visit. Her father underwent kidney
    transplantation for end-stage renal disease due
    to autosomal dominant polycystic kidney disease.
    The parents request assessment of the child's
    kidney function. Her serum creatinine measurement
    is normal for age.

Of the following, the MOST correct statement
about serum creatinine measurements in the
pediatric patient is that
  1. serum creatinine value of 0.6 mg/dL (53.1
    mcmol/L) is considered normal for a 1-year-old
  2. healthy preterm infants (lt36 weeks' gestation)
    typically have lower serum creatinine values than
    term infants
  3. males and females have similar serum creatinine
    values up to 17 years of age
  4. newborns in the first few days after birth have
    lower serum creatinine concentrations than those
    seen in 2-month-old infants
  5. serum creatinine values are related more closely
    to patient height than to patient age in children

  • Kidney function is assessed best by measurement
    of the glomerular filtration rate (GFR
  • The serum creatinine is the most frequently used
    agent to assess GFR clinically.
  • Skeletal muscle metabolism, high values during
  • The GFR in the pediatric patient increases
    throughout the first postnatal year before
    reaching adult values by approximately 18 months
    of age.
  • Newborn high values-represent maternal value,
    declines after 10 days
  • Preterms have higher values
  • 1y/o lt0.4 mg/dl

Question 8
  • A parent requests referral to a urologist for her
    7-year-old son because of his bedwetting problem.
    He has no urinary incontinence during the day and
    is otherwise healthy. Physical examination
    reveals normal growth parameters and normal
    genitalia with a circumcised phallus. Dipstick
    urinalysis results are normal, with a specific
    gravity of 1.025.

Of the following, the MOST appropriate next step
  1. a complete blood count
  2. psychological evaluation
  3. reassurance and a follow-up visit in 6 months
  4. referral to a urologist
  5. renal/bladder ultrasonography

Nocturnal enuresis
  • Involuntary passage of urine during sleep in
    children gt5 y/o and occurs in approximately 15
    of children at age 5 and 1 of teens at age 15.
    There is a male predominance and often a positive
    family history.
  • Child with NO daytime wetting, NO dysuria and
    normal UA renal very unlikely
  • reassurance and a follow-up visit in 6 months
  • Child with BOTH daytime and nighttime wetting,
    older than 6y/o, enuresis encopresis, or
    urinary symptoms? further eval
  • assess genitourinary anatomy, exclude trauma from
    sexual abuse, detect lumbosacral spine anomalies,
    and exclude bladder dilatation or abdominal mass.
  • Older children and children for whom nocturnal
    enuresis is related to social dysfunction, family
    stress, or poor self-esteem may benefit from
    therapy to target those effects.
  • The use of a bedwetting alarm has the highest
    rate of success in young children.

Question 9
  • You are examining an asymptomatic adolescent male
    for his annual health supervision visit. Genital
    examination reveals genitalia at Sexual Maturity
    Rating 5 and a nontender mass in his left scrotum
    that extends from the inguinal canal to the upper
    pole of the testis The mass decreases in size
    when he lies down.

Of the following, the MOST likely diagnosis is
  1. direct inguinal hernia
  2. Hydrocele
  3. Spermatocele
  4. testicular tumor
  5. varicocele

  • Develops slowly
  • usually asymptomatic
  • gt15-25y/o
  • gt left side (drain to renal vein)
  • vary in size, can extend from the testis to the
    inguinal canal, and feel like a "bag of worms"
  • INCREASE in size with standing or valsalva
  • REDUCE when lying down
  • If a varicocele develops suddenly, does not
    reduce in the supine position, or is on the right
    side, a cause for obstruction of the spermatic
    vein should be sought.

Pampiniform plexus
Why not?
  • Inguinal hernias painless, intermittent groin
    masses that appear with straining and usually
    reduce spontaneously.
  • They may increase in size and become obstructed,
    resulting in a painful scrotal mass.
  • Hydrocele fluid within the tunica vaginalis that
    surrounds the testis rather than being distinct
    from it.
  • Transilluminates
  • Spermatoceles are cystic lesions within the
    spermatic cord that are above and distinct from
    the testis and transilluminate.
  • Testicular tumors are painless solid masses
    within the testicle that do not transilluminate.

Question 10
  • The attending neonatologist notifies you that she
    is caring for a newborn boy in your practice who
    has multiple congenital anomalies. The baby was
    transferred from the newborn nursery to the
    intensive care unit due to cyanosis.
    Echocardiography reveals findings consistent with
    tetralogy of Fallot. The infant has a cleft
    palate. Chest radiographs show multiple thoracic
    hemivertebrae. Renal ultrasonography documents
    unilateral renal agenesis. On physical
    examination, the infant has hypoplastic thumbs.
    The baby is normally grown and vigorous.

Of the following, the MOST likely diagnosis for
this infant is
  1. CHARGE syndrome
  2. Fanconi anemia
  3. trisomy 18
  4. 22q11 deletion syndrome
  5. VACTERL association

  • CHARGE syndrome
  • C coloboma
  • H heart
  • A atresia choanae
  • R retardation of growth and/or development
  • G genital anomalies
  • E ear anomalies

  • Fanconi anemia
  • AR
  • thumb hypoplasia, short stature, microcephaly,
    abnormal ears, epicanthal folds, site of ureteral
    reimplantation, congenital dislocated hips
  • bone marrow failure
  • more common among persons of Ashkenazi Jewish

  • V vertebral anomalies
  • A anal atresia
  • TE tracheoesophageal fistula
  • R renal anomalies
  • C cardiac defects
  • L (radial)limb anomalies

  • The combination of tetralogy of Fallot,
    hypoplastic thumbs, cleft palate, and a renal
    abnormality ?22q11 deletion syndrome

Recent studies have shown that tetralogy of
Fallot with pulmonary atresia belongs to a
spectrum of conotruncal cardiac malformations
that are often associated with monosomy 22q11.
The clinical presentation of monosomy 22q11
includes patients with conotruncal anomaly face
syndrome, velo-cardio-facial syndrome, and
DiGeorge syndrome. More recently these syndromes
have been incorporated as a group under the
acronym catch 22 (cardiac defect, abnormal face,
thymic hypoplasia, cleft palate, hypocalcaemia,
and microdeletion 22q11)
Question 11
  • You are evaluating a newborn in whom intrauterine
    renal US results are abnormal. The child appears
    very edematous, but requires resuscitation with
    fluids for initial respiratory distress and
    hypotension. One day later, the child appears
    more edematous.
  • He has an excellent urine output. Measurements of
    his serum electrolytes reveal
  • Na 127mEq/L
  • K 4.6mEq/L
  • Cl 92mEq/L
  • HCO3 27 mEq/L
  • BUN 10mg/dL
  • Creatinine 0.7 mg/dl
  • Albumin 0.9g/dl
  • UA no blood, but (4) protein with a random
    urine protein to creatinine ratio of 43.5.

Of the following, the MOST likely cause of this
childs clinical status is
  1. Acute glomerulonephritis
  2. Congenital nephrotic syndrome
  3. Diffuse mesangial sclerosis
  4. Focal segmental glomerulosclerosis
  5. Membranous nephropathy

Congenital nephrotic syndrome
  • Cystic formation sec to mutation in nephrin
    (BM)? leakage
  • Massive proteinuria? decrease oncotic pressure?
  • By 2 months kidneys enlarged with loss of
    coticomedullary differentiation
  • By 12 mo decrease in size with
    hyperechogenicity? fibrosis/ glomerular
    sclerosis? failure

  • Rarely in newborn period
  • Acute glomerulonephritis
  • Membranous nephropathy
  • Focal segmental glomerulosclerosis

Question 12
  • A 3 mo old boy is admitted to the hospital for
    evaluation of FFT. His bwt was at 50 and length
    at 75. Currently, his wt is below the 5 and
    length is at 25, His VS and PE are otherwise
  • He appears well hydrated.
  • Measurement of serum electrolytes reveals
    Na139, K 4.7, Cl 114, bicarbonate 12, BUN
    8, creatinine 0.3.
  • A consulting nephrologist recommends measurement
    of urine pH (which is 7.5) and urine ammonium
    (which is 12000 mcm/Lnormal is gt 60000)

Of the following the MOST likely cause of childs
acidosis is?
  1. Inborn error of metabolism
  2. Lactic acidosis
  3. Type I (distal renal tubular) acidosis
  4. Type II (proximal renal tubular) acidosis
  5. Type IV (renal tubular acidosis)

Step 1
  • Calculate anion gap? help you narrow your
  • HIGH
  • severe CRF
  • Ketoacidosis diabetic, alcoholic, starvation
  • Lactic acidosis
  • Poisonings salycilates, methanol, ethylene
  • Renal tubular acidosis
  • Diarrhea
  • Carbonic anhydrase inhibitors
  • Hyperalimentation with TPN

  • 3 types
  • Type 1 distal
  • Type 2 proximal
  • Type 4 distal
  • NO TYPE 3

Type 2-proximal
  • Inability to reabsorb HCO3? Very very alkaline
  • If distal is normal, will compensate a little by
    excreting H and the urine is 6
  • K is low or normal
  • Fanconi sd
  • Acetazolamide, 6 mercaptopurine
  • Heavy metals lead, copper, mercury, cadmium
  • Disorders in protein, CHO, AA
  • Multiple myeloma

Type 1-distal
  • Inability to excrete hydrogen, as well as
    ammonium secretion
  • Urine very very alkaloticgt7.5 with a low urine
  • hypokalemic
  • RENAL STONES-obstruction / hypercalciuria
  • Amphotericin
  • Toluene (glue sniffing)
  • Lithium
  • SLE
  • Sjogren
  • Chronic active hepatitis

Type 1
Type 4-distal
  • Affects Na/K/H exchange
  • Hyperkalemic
  • Hyperchloremic
  • Obstructive uropathy
  • Interstitial renal disease
  • Multicystic renal disease
  • Type 1 pseudohypoaldosteronism
  • Diabetic nephropathy
  • 21-OH deficiency
  • Renal transplant

Type 4
Type 1
Dont forget.
  • Anion gap Na(Cl-HCO3)
  • In RTA
  • lost of bicarbonate will actually increase
    absorption of chloridetherefore, there is a
    balance in the equation

Question 13
  • A 6y/o F had been noted by her gral pediatrician
    to have symptomatic, persistent hematuria for 2
    yrs. Her initial UA and microscopic analysis in
    your office show moderate blood, with 25-50
    RBC/hpf. Results of her renal US were normal, as
    was her urine calcium-to-creatinine ratio. Serum
    electrolytes were normal in 2 occasions.
  • Over the next 2 yrs, you ordered 4 concurrent UA,
    all of which showed moderate blood with 25-50
    RBC/hpf, without proteinuria.
  • She comes to clinic after being lost to follow up
    for 3 yrs.

Of the following, the clinical symptom or
laboratory result MOST consistent with
progression of renal disease in this child will
  1. Abdominal pain
  2. Leukocyturia
  3. Proteinuria
  4. Recurrent gross hematuria
  5. Urinary RBC casts

  • Hematuria proteinuria renal disease

Proteinuria-important facts
  • False positives highly concentrated, alkaline
  • Fixed proteinuria (day/night) requires further
  • Random urine protein/creatinine ratio gt 0.5
  • 24 hrs urine protein excretion gt 3.5 gr/day
  • Transient hematuria in fever, strenuous exercise
    and CHF
  • Benign orthostatic proteinuria higher during
    growth spurt
  • Females
  • When lying down none, when up positive
  • Microalbuminuria DM
  • gt 300 nephropathy

Question 14
You are evaluating a 10y/o boy who has
intermittent urinary incontinence. Voiding
cystourethrography detects a urethral
stricture. Of the following, the most likely
cause of this bodys urethral stricture is?
  1. Carcinoma
  2. Chronic narrowing
  3. Congenital narrowing
  4. Intermittent urolithiasis
  5. Trauma

Urethral strictures
  • Mostly secondary to trauma pelvic fx
  • gt rare instrumentation, infection(gonorrhea),
    congenital, complication of balanitis, cancer
  • SYMPTOMS Straining to urinate, decrease in size
    and force of urine stream, persistent sense of
    bladder fullness, urine dribbling, and freq and
    urgency of urination
  • lt2cm endoscopic dilatation

Question 15
  • A 10y/o F presents to the ER with a 1 day hx of
    brown urine. She reports no dysuria, urgency or
    abdominal or flank pain. Her VS T 98.8, BP
    165/97, HR 84, RR 20. On PE, moderate
    periobital edema is evident, but here are no
    other abnormalities. UA reveals moderate blood,
    and 4 protein.
  • The serum C3 concentration is low and the C4
    concentration is normal.

Of the following, the most likely cause of this
girls hematuria is?
  1. Focal segmental glomerulosclerosis
  2. Immunoglobulin A nephropathy
  3. Lupus nephritis
  4. Membranous proliferative glomerulonephritis
  5. Postinfectious acute glomerulosclerosis

  • Gross hematuria hypertension periorbital
    edema decreased C3 and normal C4
  • Self-limited
  • C3 will be back to normal in 8wks
  • HTN sec to Na water retention up to 3 months

Nowlets go for a case
  • A 4mo M infant presents with a hx of poor wt gain
    and irritability. FT, NSVD, Bwt3.5kg. He was BF
    for 3 months and appeared to have satisfactory wt
    gain initially. He was then switched to formula
    feeds, which he has been taking well. Mom says
    his diapers are always soaking wet. His
    development has been normal and his vaccines are
  • On PE, you find an infant that is thin with wt
    lt5 and ht lt25. He appears to be irritable, with
    midly sunken anterior fontanel, an umbilical
    hernia and mild bilateral tibial curvature.

Lab studies
  • Serum
  • Hb 10.8 hct 32.9
  • BUN 17, creat 0.5
  • Na 148
  • K 3.7
  • Cl 114
  • Bicarb 20
  • Calcium 9.8
  • Phosphorus 5.5
  • Alk Phos 360
  • Mg 1.9
  • Glucose 72
  • Urine
  • S. gravity 1.005
  • Urine pH 6.8
  • Urine osm 198

The serum osm on this pt is?
  1. 296
  2. 302
  3. 306
  4. 300
  5. None of the above

Serum osmolarity
  • 2Na (BUN/3) (glucose/18)

Normal 285-295
The most likely cause for this infants failure
to thrive is?
  1. Metabolic acidosis because of renal tubular
    acidosis an urinary concentration defect
  2. Nephrogenic diabetes insipidus
  3. Bartter syndrome with polyuria
  4. Gittelman syndrome
  5. Liddle disease

In this case, baby developed early because
initially on breast milk which has less sodium,
less protein and less osmolar load, compared to
formula which has higher solutes. While baby on
breast milk ? less water loss
  • Calculate anion gap

Diabetes insipidus Serum HIGH Na HIGH
osmolarity Urine LOW Na LOW osmolarity
  • Bartter syndrome defect in Na-K-2Cl
    cotransporter on the loop of Henle
  • Loss of Na, K, Cl
  • Hypokalemic, hypochloremic metabolic alkalosis
  • Gitelman syndrome older children, defect in
    Na-CL cotransport in the distal convulated tubule
  • Loss of Na, K, Cl, Mg
  • Hypokalemic, hypochloremic metabolic alkalosis
  • Liddle syndrome adolescents and adults,
    upregulation of Na channel in principal cell of
    cortical convulated tubule
  • Excessive Na absorption with hypoK due to
    exchange and loss in urine
  • HTN/ deafness/ blindness

Other laboratory investigations that may be
helpful include
  1. Spot urine calcium-to creatinine ratio
  2. Serum vasopressin levels
  3. Nasal vasopressin (DDAVP) test
  4. 1 and 3
  5. All of the above

  • Diabetes insipidus ADH problem
  • Nephrogenic insensibility to ADH
  • Central no production of ADH
  • Do a vasopressin test
  • Give 1 dose of DDAVP intranasal and collect urine
    over the next 5hrs
  • Nephrogenic unable to concentrate urine
    persists low urine osm (lt200)
  • Central response with concentrated urine

The disease is most commonly inherited as?
  • AR
  • AD
  • X-linked recessive
  • X-linked dominant
  • None of the above
  • Remember the case

  • Congenital Nephrogenic DI
  • 90 X-linked recessive
  • Common symptoms
  • Hypernatremia
  • FTT on a baby switched from Breast Milk to
  • 10 sec to mutation in aquaporin 2

This condition is most appropriately treated with?
  1. Low-solute diet
  2. Thiazide diuretics amiloride indomethacin
  3. Thiazide diuretics indomethacin
  4. All of the above
  5. 1 and 3

Treatment? GOAL avoid dehydration
  • Decrease solute load? Free water replacement,
    change to breast milk
  • ADD diuretics Thiazides
  • Add K-sparing diuretic amiloride
  • Add prostaglandin synthesis inhibitors
  • acts on mesangial cells in the glomerulus
    increasing GFR