Download - November Board Review
NOVEMBER BOARD REVIEW
Renal: Part I
Test Question
You like having 15 questions during board review instead of 10.
A. True
B. False
Hematuria
Question #1 The mother of a 5-year-old female brings her daughter to
your clinic on Monday morning because when she went potty this morning her urine was red. She is afebrile and has no complaints of dysuria or musculoskeletal pain. Her BP is 94/55 and her urinalysis is negative for blood, protein, nitrites, and leukocyte esterase. Microscopy reveals 1 RBC and no casts. You notice scratches on the girls fingers, and her mother reports that they have just returned from a friends farm and went “berry pickin” over the weekend.
Of the following, the next MOST appropriate step is: A. Reassurance B. Renal U/S C. Creatinine kinase D. BMP E. Urine culture
Hematuria 5 or more RBCs per high-power field in 3
consecutive fresh, centrifuged specimens obtained over the span of several weeks
(+) dipstick for hemeMyoglobinuriaHemoglobinuria
(-) dipstick for hemeDrugs (sulfa, nitrofurantoin, salicylates,
phenazopyridine, phenolphthalein)Toxins (lead, benzene)Food (food coloring, beets, blackberries, rhubarb,
paprika)
Glomerular Bleeding
Discolored urine RBC casts Distorted RBC morphology
Causes
Microscopic Macroscopic (Gross)
Symptomatic
Asymptomatic + proteinuria
Isolated asymptomatic
Gross Hematuria
Underlying cause is found in 56% of cases
Common causes:UTITraumaCoagulopathyCrystalluriaNephrolithiasis
Question #2 The mother of a 3-year-old male comes to clinic for follow-up of
hematuria. The results of today’s UA are: pH 6.0 3 + blood Negative for protein, nitrite, and leukocyte esterase 10 to 20 RBCs/HPF 0 WBCs
These results are similar to the UA you performed 2 weeks ago. The patients BP is 105/58, but otherwise the physical exam is normal. Being the astute clinician that you are, you ask mom about any family history of renal disease. She mentions that both of her older brothers are on dialysis.
Of the following, the MOST likely cause of this patient’s hematuria is: A. Benign familial hematuria B. Polycystic kidney disease C. Alport syndrome D. Sickle cell disease E. Ureteropelvic junction obstruction
Family History is Important! Alport syndrome
X-linked (85%), autosomal recessive, and autosomal dominant
Mutation in Type IV collagen of GBMKidney failure by 2nd or 3rd decade in malesSensorineural hearing loss Anterior lenticonusFemales may only have microhematuria
Family History is Important! Benign familial hematuria
Autosomal dominant○ But many people are unaware
Also mutation in type IV collagen of GBMMicroscopic hematuria with occasional
gross episodic hematuria (<10%)Proteinuria and HTN are unusual
Family History is Important! Sickle cell disease and trait
Occlusion of the vasa recta capillaries result in renal infarct
Hematuria more common in malesUnilateral, left more commonRecurrence in 40% of casesContributing factors
○ Hypoxia○ Acidosis○ High osmolality○ Stasis
Symptomatic Microscopic Hematuria If accompanied by elevated proteinuria on
first morning urine → higher likelihood of underlying renal disease
Clinical manifestationsNonspecific
○ Fever, malaise, weight changeExtrarenal
○ Malar rash, purpura, arthralgia/arthritis, headachesLocalized
○ Dysuria, suprapubic pain, flank pain, edema, oliguria
Question #3 The results of a urinalysis for a 13-year-old male in your
practice reveal: pH 6.0 3+ blood Negative glucose, protein, nitrite, and leukocyte esterase 5 to 10 RBCs/HPF
He has never noticed any changes in his urine, has no complaints, takes no medications, and has no family history of kidney disease.
Of the following, the MOST likely associated urinary finding is: A. Bacteriuria B. Hypercalciuria C. Hemoglobinuria D. Protein-to-creatinine ratio 1.0 E. Myoglobinuria
Isolated Asymptomatic Hematuria Rarely have significant renal disease 25% normalize within 5 years Rarely have gross hematuria Get good family history! Monitor for HTN and proteinuria Hypercalciuria
Risk for urolithiasisUrinary Ca/Cr > 0.2 or 24 hour urinary calcium
excretion > 4 mg/kg/dayMostly idiopathic
○ Consider immobilization, diuretics, vit D intoxication, hyperparathyroidism, and sarcoidosis
Question #4
A 14-year-old female has 3+ blood, 2+ protein, and 10 to 20 RBCs/HPF on urinalysis. She has no symptoms.
Of the following, the BEST next step is:A. Refer to nephrologyB. Renal U/SC. Urine cultureD. Urinary calcium-to-creatinine ratioE. Repeat UA with first morning urine
Asymptomatic hematuria + proteinuria In most cases, resolution of one or both
features Determine if proteinuria is orthostatic
First morning urine Persistent proteinuria is more indicative
of a glomerular process Refer to nephrology
Diagnostic Evaluation
Diagnostic Evaluation First stage
BP, UA +/- urine culture Second stage
Search for underlying disease especially if edema, HTN, systemic symptoms, etc.○ BMP○ ASO○ Complement○ ANA○ Hepatitis panel○ HIV○ CBC○ Hgb electrophoresis
Renal U/S, biopsy, cystoscopy when indicated Refer to nephrology unless the cause is clear (UTI, postinfectious)
Question #5 An 8 yo M presents to the ED with c/o “dark urine” for
the past 24 hours. Per Mom, this has never happened before. He is a very healthy boy, with the exception of being treated with antibiotics for a sore throat 2 weeks ago. On exam, his BP was found to be 130/82, and there was some mild periorbital edema bilaterally. Of the following, the most likely set of laboratory findings in this patient is:A. Normal complement levels; 3+ protein, no blood on UAB. Elevated complement levels; 1+ protein, 1+ blood on UAC. Low complement levels; trace protein, 3+ blood on UAD. Low complement levels; 3+ protein, no blood on UAE. Normal complement levels; no blood or protein on UA
Acute poststreptococcal glomerulonephritis (PSGN)
Pathophysiology Caused by a reaction to a nephritogenic
strain of group A beta-hemolytic Streptococcus
Multiple pathogenic mechanisms inflammation of the glomeruliDeposition of Ag-Ab complexes in the glomeruliIn situ deposition of nephritogenic Ag with
formation of immune complexesDirect activation of complement by the
nephritogenic Ag within the glomeruli
Presentation
Timeline10-14 days after pharyngitis3-6 weeks after pyoderma
Clinical featuresClassic nephritic syndrome
○ Gross hematuria○ Edema (fluid overload can pulmonary
edema)○ HTN○ Renal insufficiency
Laboratory Findings Low C3 UA
Hematuria*ProteinuriaRBC casts
BMPMild renal insufficiency
Evidence of past streptococcal infectionStreptozymeAnti-DNAase B
Question #6 Of the following, which most accurately
describes the natural course of PSGN:A. Renal function improves within 3 weeks,
complement values normalize within 8-12 weeksB. Renal function improves within 6-24 months,
complement values normalize within 8-12 weeksC. Renal function improves within 3 weeks,
complement values remain low indefinitelyD. Renal function continues to deteriorate,
complement levels remain low indefinitelyE. Renal function improves within 3 weeks,
complement values normalize within 2-4 weeks
Treatment and Prognosis
Supportive managementAntibiotics (Rx Strep infection)For Fluid overload:
○ Fluid/ Na restriction○ Diuretic therapy
Monitor electrolytes and renal functionAnti-hypertensives
Treatment and Prognosis Prognosis is excellent!
Renal function improves within 3 weeksComplement values normalize within 8-12
weeksMicroscopic hematuria may persist 6-24 months
Indications for renal biopsy:Renal function or BP abnormal for >4wksProteinuria present for >6mosSerum complement concentrations remain low
for >12wks
Enuresis
Definitions Primary nocturnal enuresis = nighttime wetting in a
child who has never been dry on consecutive nights for longer than 6 monthsDryness is expected to be achieved by 5 years of age10 to 15% of 7-year-olds still have bedwetting99% of children are dry by 15 years
Incontinence = uncontrollable leakage of urine that may be intermittent or continuous and occurs after continence should have been achieved Leakage that occurs during the day is daytime
incontinence Dysfunctional voiding = inappropriate muscle
contraction during voiding
Question #7 A 7-year-old boy has nighttime bedwetting. No one
else in the family wet the bed, but his mother his concerned about his weight and that he is constantly tired during the day. Other than being overweight, his physical exam and screening UA are normal.
The MOST likely cause of his nocturnal enuresis is:A. Genetic predispositionB. Bladder dysfunctionC. He is a “deep” sleeperD. Occult spinal dysraphismE. Obstructive sleep apnea
Causes of Nocturnal Enuresis No data to support “deep”
sleep theory
Obstructive sleep apnea↑ atrial natriuretic factor leads to increased
diuresisT & A has been shown to cure enuresis
Abnormal circadian release of ADH
Causes of Nocturnal Enuresis Bladder dysfunction
Smaller-than-normal functional bladder capacity at night
Higher bladder instability
Daytime + Nighttime = higher degree of abnormalities and treatment failure
Causes of Nocturnal Enuresis Genetics
1 parent with enuresis = 44% chance of child affected
2 parents with enuresis = 77% chance of child affected
Psychological factors30% greater chance of enuresis in kids with
ADHD Maturational delay
Fine and gross motor clumsiness, perceptual dysfunction, speech defects co-exist
Secondary Enuresis
New-onset nighttime wetting on consecutive nights after a 6-month or greater period of dryness
Usually not related to an organic cause Stressful events can be the source
Birth of a sibling, move, death in the family
EvaluationHistory Physical Labs
Nights/week Distended bladder Urinalysis +/- Urine cx
Episodes/night Fecal impaction
Fluid intake Phallus and meatus
Caffiene Labial adhesions
Polyuria, polydipsia Muscle tone
Urgency, frequency, dysuria
Reflexes and sensation
Abnormal urine stream Skin over spine (tuft of hair or sacral dimple)
History of UTIs
Constant wetness
Bowel complaints
Sleep apnea
Neuro/dev history
Question #8
An 8-year-old female is diagnosed with primary nocturnal enuresis. The parents are interested in therapy.
The MOST effective treatment for ending the enuresis is:A. DesmopressinB. Alarm therapyC. ImipramineD. AnticholinergicsE. Limiting dairy products before bed
Treatment of Nocturnal Enuresis
Behavioral Medical
Limit nighttime fluid intake Desmopressin
Limiting dairy products 4 hours before bed
Anticholinergics
Voiding before bed Imipramine
Alarm therapy Combination therapy
Alarm Therapy Most effective
Success rates as high as 66 to 70%
Most difficult to employ Must be used every
night Requires 3 to 4 months
for results Parents may need to
wake up child if the child does not wake to alarm
Offers a real cure No adverse effects
Daytime Wetting
Can be caused by stressful eventsDivorce, death in the family, abuse
Children with daytime wetting may have a difficult temperamentIncreased risk for constipation and
encopresis
Classification of Daytime Wetting Storage problem
Neurologically normal who cannot fill and storeNeurologically abnormal who have high pressure
bladderHypersensitive bladderInadequate sphincter tone
Emptying problemFailure to empty completely with little residual
urineMay be neurologic, anatomic, muscular, or
fucntional
Question #9
A 7-year-old female patient has nighttime and daytime wetting. You order a UA and urine culture. Her physical exam is normal.
Which of the following should also be included in your initial evaluation?A. Post-void residualB. VCUGC. UrodynamicsD. MRI of the spineE. Cystoscopy
EvaluationHistory Physical Labs
Age of toilet training Meatal stenosis UA
Pattern of wetting Hypospadias Urine culture
Volume of wetting Tight phimosis Postvoid residual
Times/day Female epispadias
Time of day (during play)
Labial adhesions
History of UTIs Intralabial masses
Nighttime wetting Back and sacrum
Bowel function (“skid marks”)
Rectal exam
Social history
Ectopic Ureter Females No history of day- or
nighttime dryness “Constant dribbling” Evaluate with MR
urography, CT, or IVP
Refer to pediatric urology
Manifestations of Storage Problems Urge incontinence
Frequent attacks of a strong desire to urinate countered by hold maneuvers such as squatting, dancing, and curtseying
Uninhibited bladder contractions
Dampness rather than soaking
Functional bladder capacity is usually small
Storage Problems
Overflow incontinenceInfrequent and incomplete voidingOvertime decreased sensation of the need to voidUsually large wetness
Daytime incontinenceInfrequent or delayed voiding, especially
associated with distraction or playSmall to large urine lossAssociated with behavior problemsDevelopment after continence should prompt
referral
Storage Problems
Urinary frequencySudden need to urinate very frequently,
sometime up to 30 times per dayAges 3 to 8Self-limitedRelated to psychological stressors
Manifestations of Emptying Problems Lazy bladder syndrome
Void 3 or fewer times a day Must strain abdominal muscles to void Intermittent stream and cannot empty bladder completely Recurrent UTIs Constipation
Detrusor sphincter dyssynergia (DSD) Inappropriate contraction of the
external urethral sphincter during bladder
contraction Staccato type of voiding Post-void residual “spinning-top urethra”
Emptying Problems
Hinman syndromeNonneurogenic neurogenic bladderLongstanding DSD leads to detruser
decompensationCan lead to renal insufficiency and failure
Other Types of Daytime Wetting
Giggle incontinenceComplete bladder emptying with extreme
laughterFemales age 10 to 20No associated voiding abnormalitiesCataplectic phenomenon that exists in
patients with narcolepsy
Question #10 The mother of a 5-year-old female complains that
her daughter’s underwear is always damp, even just after urinating. The girl states that she feels dribbling soon after she goes pee-pee. The patient is overweight, and sometimes has trouble balancing on the toilet.
The MOST likely cause of her symptoms is:A. ConstipationB. Vaginal refluxC. Urinary tract infectionD. Lazy bladder syndromeE. Daytime incontinence
Other Types of Daytime Wetting
Vaginal refluxDribbling associated with urine being trapped in
the vaginal introitus after voiding and leaking out when the child walks away
Often seen in overweight and young girlsAlso seen with vaginal adhesionsUnderwear is “always damp”Diagnose by postvoid vaginal exam with Valsalva
eliciting urine from the introitusTreat by having patient sit backward on toilet and
keep thighs separated
Therapy Behavioral therapy
Encourage voiding q 2 hoursAvoid bladder irritants (caffiene, carbonated
drinks, citrus-content beverages, red dyes)Sit on the toilet 30 minutes after a large meal
with feet supported for 10 min (pelvic floor relaxation)
Bowel programMost patients have some form of constipationHigh-fiber dietMedications (polyethylene glycol)
Therapy
Anticholinergic agents for urinary frequency
Biofeedback for emptying problems (DSD, etc)
Alpha-blocking drugs for emptying problems
Nephrotic syndrome
Nephrotic Syndrome
Heavy proteinuria and hypoalbuminemia Edema Hyperlipidemia
Pathophysiology of Proteinuria
Edema
Pathophysiology of Edema Classic theory:
Decrease in plasma oncotic pressure secondary to hypoalbuminemia water extravasation into the interstitial space decrease in intravascular volume activation of the RAA system aldosterone increases reabsorption of Na edema
Not fully supported by clinical evidencePlasma volume decreased only in some childrenStudies have failed to demonstrate elevations in
the RAA hormones
Pathophysiology of Hyperlipidemia Increased VLDL, IDL, and LDL
secondary to:Overproduction in the liver due to low
plasma albumin concentrationLow oncotic pressure and impaired
catabolism of apolipoprotein B and VLDL chylomicrons
Epidemiology Incidence: 2.7 new cases/ 100,000 children per
year Sex predilection: 2:1 (males:females) in
childhood; sex difference wanes by adolescence
Increased familial incidence (siblings) Mean age of onset 3.4 yrs (Asians) and 4.2 yrs
(Europeans) African American and Hispanic children have
greater incidence of nephrotic syndrome, a more severe form and poorer prognosis
Differential Diagnosis
ClassificationPrimary Secondary
Minimal change nephrotic syndrome (MCNS) 85% of cases
Focal segmental glomerulosclerosis (FSGS) 10-15% of cases
Membranous nephropathy (MN) 4% of cases
Question #11
Which of the following is the best prognostic indicator in children with nephrotic syndrome?A. Age< 10 yo at time of diagnosisB. UPr/Ucr <4.0C. Steroid responsivenessD. Serum creatinine <1.1E. Serum albumin>2.0
Further Classification…
Steriod-sensitive nephrotic syndromeMCNS
Steriod-resistant nephrotic syndromeCongenital nephrotic syndromeFSGSMN
Minimal Change Nephrotic Syndrome
Histopathology
Light microscopy glomeruli normal Electron microscopy fusion of the
epithelial foot processes
Clinical Features
Additional symptoms:AnorexiaIrritabilityFatigueAbdominal discomfortDiarrhea
Respiratory tract infection preceding onset common (not likely pathogenic)
History of allergy is reported in 50% of children with MCNS
Question #12 A 4 yo M presents to your office with a 3 day h/o
diarrhea, irritability, and poor PO intake. His eyelids have also been swollen for 2 days, which Mom attributed to “pink eye.” This morning, she noticed that his scrotum appeared very swollen and became concerned. You suspect nephrotic syndrome. A urine protein to creatinine ratio greater than what value would confirm your suspicion?A. 0.2B. 0.5C. 1.0D. 2.0E. 3.0
Laboratory Features
Plasma protein markedly reducedAlbumin <2.5
ProteinuriaEstimation by dipstickConfirmation by quantitative measurement
○ 12 or 24 hour timed urine collection>50mg/kg/d or 40mg/m2 indicative of nephrotic
syndrome
○ UPr/UcrNormal: Age >2 yo= <0.2, Age 6mos-2 yrs= <0.5Nephrotic syndrome: >3.0
Laboratory Features
Elevated cholesterol, TG, and lipoproteins
Low NaHyperlipidemiaRetention of water (increased ADH)
Low CaHypoalbuminemia
Question #13 A 4 yo F presents with a 2 day h/o worsening
periorbital and labial swelling. Her BP is normal and PE unremarkable except for the above noted edema. Her UA shows 3+ protein and trace blood with 0-2 RBC/hpf. BUN and Cr are normal along with C3. Albumin is 2.1 and LDL 165. Of the following, which is the next best step in her management? A. Renal biopsy B. Prednisone therapy C. Dialysis D. Bilateral nephrectomy E. Cyclosporine therapy
Question #14 What anticipatory guidance should you give the
patient’s family regarding the course and prognosis of MCNS?A. Your daughter will likely go on to develop ESRDB. After one course of steroids, your daughter will likely not
need anymore treatment for this illnessC. Your daughter will likely respond to the steroids; however,
there is a strong probability that she will eventually relapseD. Your daughter will not likely to respond to the steroids
and will need a renal biopsyE. Your daughter will likely be admitted to the hospital
several times in the next month from complications of this illness
Treatment and Course
Indications for Renal Biopsy
Congenital Nephrotic Syndrome (CNS)
Presentation Massive proteinuria that starts during fetal life Elevated AFP with normal US findings Most affected children born preterm (~2500g) Edema and abdominal distension evident
soon after birth Albumin usually <1.0
Also losing many other proteins metabolic disturbances (lipid abnormalities) atherosclerotic changes as early as the first postnatal year
Treatment
InitialSustaining a good nutritional stateControlling edemaPreventing complications
Uni-or bilateral nephrectomyTo control massive loss of protein
Eventual kidney transplantCNS can recur in transplanted kidneys
Focal Segmental Glomerular Sclerosis (FSGS)
Histopathology
Initially, is sclerosis of some of the glomeruli (focal) that involves only part of the glomerular tuft (segmental)
Progresses to
global, extensive
glomerulosclerosis
and tubular atrophy
Causes Heterogeneous
Genetic ○ Small percentage
IdiopathicHeroin-induced
nephropathyAIDSMultiple myelomaAlport syndromeReflux nephropathyDiabetic nephropathyObesity
Clinical Features
Major signs edema and albuminuria, but HEMATURIA more frequent in FSGS than in MSNS
FSGS cannot be diagnosed at presentationMost children are started on prednisone
therapy and lack of response at 4 weeks prompts renal biopsy diagnosis of FSGS
20% are responsive to prednisone
Clinical Features (con’t)
Disease progression variableESRD reached b/t 2-10 yrs In patients who rapidly progress to ESRD,
there is a high likelihood of recurrence in the transplanted kidney
Treatment NO DEFINITIVE EVIDENCE THAT ANY
DRUG IS EFFECTIVE!!Pulse methylprednisolone: minimal benefitAlkylating agents (cyclophosphamide): little
therapeutic effectCyclosporine
○ Induces remission in 25-50% in those with steroid-resistance
○ Patients relapse promptly when the drug is discontinued
○ Serious adverse effects if the drug is continued for long periods
Treatment (con’t)
Recurrence in transplanted kidney is a major problemReported in up to 50% of transplanted
children with FSGSRisk factors:
○ Older than age 6 at onset○ Progression to ESRD in less than 3 years
Treated with cyclosporine +/or plasmapheresis○ Partial or total remission in a minority of cases
Membranous Nephropathy
Histopathology
Diffuse, irregular thickening of the GBM in the absence of any signs of inflammationElectron microscopy: electron-dense
deposits distorting the GBM
Cause Infections
Hepatitis BMalariaSyphilis
AI diseaseSLECrohn disease
TumorsWilms tumorNeuroblastoma
Idiopathic Drugs
Clinical Features Very rare in children but can present at any
age Presentation
Proteinuria or nephrotic syndrome(Hematuria and HTN rare)
TreatmentSteroids and immunosuppressive drugs (not good
results) Clinical course
Spontaneous remission in 25-50%25-30% develop renal insufficiency
Question #15
A 5 yo F with h/o MCNS presents to the ED with a one day h/o fever to 102, chills and mild abdominal pain. What illness must you consider in this patient?A. PneumoniaB. Adenovirus gastroenteritisC. Shigella gastroenteritisD. PeritonitisE. Pancreatitis
Complications of Nephrotic Syndrome ARF Thromboembolic events
Due to loss of antithrombin III and protein S in the urine
Antiphospholipid syndrome Infections
Due to loss of factor B, a decrease in IgG and impaired T-cell function
Most common infection= peritonitis○ Streptococcus pneumoniae (decreasing with
vaccination)
Complications of Nephrotic Syndrome Anasarca and pulmonary edema Stunting of growth
Side effect of prolonged steroid use Reduced bone mineral density
SteroidsVit D deficiency
Ancillary Therapies Diuretics +/- salt-poor albumin
Edema only requires treatment when associated with severe ascites, peritonitis, respiratory distress or heart failure
Albumin usually given when serum albumin <1.5 ACE inhibitors/ ARBs Statins Vaccination
Conjugated pneumococcal vaccine Low Na diet Vitamin D and Ca supplementation