Pediatric Nephrology Flashcards
What’s red flag signs/components of history for nephrology issues in children?
History of:
- hematuria
- proteinuria
- abdominal/costovertebral angle/flank pain
- recent serious pain or trauma
- sudden weight gain or edema
- complicated birth (especially oligodendrogliomas/polyhydramnios)
- **congenital anomalies with eyes/ears or external genitalia (this is common)
How to take BP in children
Right upper extremity and the cuff should cover 2/3rds of the child’s upper arm.
- peripheral pulses should also be palpable
should also always palpate the abdomen, even this has nothing to do with BP
should have BP measured every year starting at 3 yrs
Labs to observe for urinary function in children
BUN:creatinine ratio
- normal = 10:1
- increases with urine flow decreases, obstruction and dehydration
most single reliable indicator of GFR is the serum level of creatinine
What are the basic 3 steps in a routine urinalysis?
Gross inspection
Dipstick screening
Microscopic examination
What does smoky-brown or tea-colored urine imply?
Glomerulonephritis
- this is indicative of stagnated blood that is decomposed with its iron oxidized
What are causes of frank hematuria (very bright red urine)
Trauma
Kidney stones
UTI’s
Strenuous exercise
Secondary HTN and children
Most common in younger children
- most often caused by renal abnormalities (if they have elevated BP, need to check for renal or CV abnormalities)
- severely elevated BP (stage 2) and symptomatic HTN suggest secondary HTN more in children
Causes includes: 10%
- glomerulonephritis
- VUR/ obstruction nephropathy
- HUS
- congenital abnormalities of urinary tract
renovascular HTN accounts for 90% of secondary HTN
Prune belly
“eagle-Barrett syndrome”
Congenital abnormality where a child is born without abdominal musculature
- also shows renal and Urinary tract abnormalities
- **75% of these cases present with dilated ureters and VUR
- may also show cryptochidism
- may also show intestinal malrotation
wayyyy more common in boys (20x more)
major determinant of prognosis = degree of cystic renal dysplasia
Treatment = early orchiopexy and just monitor
Cryptochidism
Undescended testies
- very common male pediatric disorders, especially in premature children (33%)*
- 75% will spontaneously descend by 3 months. If they dont by 6 months (but especially by 15months ) probably need surgery
uncorrected cryptochidism = increased risk of infertility and testicular malignancies
To check for this, must check the placement and turgor of the testicles on all physical exams for infants and well check ups
Treatment = surgery after 6 months-18 months
- never use hormonal therapy
When should a disorder of sex development be suspected always?
In a phenotypic male with bilateral non palpable testies
- in this case it could be a virilized female with congenital adrenal hyperplasia
Risk always goes up the less palpable the testicles are
Congenital adrenal hyperplasia (CAH)
Is a autosomal recessive disorder of cortisol biosynthesis (usually deficiency)
- causes an increase in the secretion of adrenocorticotropic hormone (ACTH) which in turn leads to adrenal hyperplasia and increases in intermediate metabolites production
Usually leads to precocious puberty in males and sexual infantilism in females
- will change the infants genitalia if not corrected (females will have enlarged clitoris which looked like a penis, and males will have either normal looking or cryptochidism
- *can be life threatening since uncorrected cortisol deficiencies can lead to low aldosterone production = salt-wasting and hyponatremia**
- is termed simple virilizing disease if the aldosterone is not reduced.
What is the most common cause of CAH
21-hydroxylase deficiency
- this enzyme is required for the synthesis of cortisol and aldosterone
- if you dont have this enzyme, cortisol and aldosterone turns into testosterone
Symptoms of serious CAH
Usually present by 10-14 days of age
Progressive weight loss
Anorexia
Vomiting
Dehydration
Weakness
Hypotension*
Hypoglycemia and hyponatremia*
Hyperkalemia*
- = most dangerous and will lead to shock if not corrected
Postnatal androgen excess
Untreated CAH deficiency produces this
- * harder to see in males since they will appear normal and don’t usually develop adrenal insufficiency
Signs:
- rapid somatic growth and accelerated skeletal maturation with premature closure of epiphyseal plates(look super tall when young, but short at adulthood)
- increase pubic and axillary hair for their age
- premature acne and deep voice
- enlarged penis/scrotum with normal testie size
What ages are UTIs most common in children?
First year = #1
- male:female ratio = 2.8:5.4
(Females more likely to get it)
- **if a male is going to get a UTI, It is far more common in the 1st year of life
- **more common in uncircumcised males
- first UTI females is usually by the age of 5yrs old
Beyond first year male:female ratio = 1:10
commonly presents with a fever with NO OTHER symptoms
Pathogenesis of UTI in children
Almost all are ascending infections and arise from fecal flora
If not treated will cause pyelonephritis over time
Common causes
- dysfunctional voiding (leads to increase risk of bacterial colonization)
- constipation
- urinary tract obstruction
- neurogenic bladder
- poor sanitation
- sexual activity
Future consequences of pyelonephritis at a young age
Inflammatory response and scar formation of pyelonephritis can lead to:
- CKD
- HTN
- renal failure
Pyelonephritis rates are highest in younger children at what he group?
Younger than 2yrs old
- **always check the urinary tract if a patient presents febrile and no other symptoms
Clinical findings of UTI in young children
Nonspecific signs all around:
- fever
- hypothermia
- jaundice
- poor feeding
- irritability
- vomiting
- failure to thrive
- septic symptoms
- abdominal pain
- vomiting
- pain while urination
- enuresis/ high levels of accidents
almost never shows CVA tenderness if pyelonephritis
urine often is strong foul smelling and cloudy on appearance
Laboratory findings of UTI
Pyuria (> 5 WBCs/Hpf)
Leukocyte esterase positive
Nitrite positive
- 70% with UTI will show a NEGATIVE test
- this is because kids pee a lot so bacteria doesnt have the time to produce nitrites
- ***GOLD STANDARD = UA culture
- takes a while though and difficult as well to make sure its not contaminated
- if UA culture shows >100,000 cfu = definitive infection of that pathogen
What are techniques to increase good specimen collection?
Catch in midstream
Separate labia in girls and retract foreskin in boys
Super younger patients/infants = bladder catheterization or suprapubic collection is almost always needed to avoid contamination
DONT send a bagged urine culture = almost always contaminates
Why should you presume pyelonephritis in any children that is febrile and has a confirmed primary/secondary UTI?
Because pyelonephritis is the most dangerous result of a UTI with long term effects
- leads to increased renal scarring and CKD risk
What kind of imaging should be done in all newborns to screen for urinalysis abnormalities
Ultrasound
- recommended in children of 2-24 months
- screen kidneys,ureters, bladder
is a VCUG required in all cases of initial UTI?
NO
- is really only 100% indicated if ultrasound suggests hydronephrosis is present or if a child has recurrent febrile UTIs (not on the first one)
- *because we attempt to minimize VCUG use, educated parents to return for evaluation of subsequent fevers (rate of renal scarring increases between days 2-3 of a fever)
- scarring also increases with # of overall episodes of pyelonephritis and high grade VUR**
What is the fever cut off for any newborn?
100.4 F (38C)
Why does a infant who is less than 60 days that has a fever automatically get cultures and referred to critical care?
They dont have their own innate immune system
- living off of mothers antibodies
What drugs are first line theropy in children <36 months who have a UTI?
Cephalexin or ceftriaxone
- 10 day does with 12.5-25 mg per dose
- **cephalexin for cystitis especially
2nd Line= SMX-TMP
What drugs are first line therapy in children 36 months-18 yrs months who have a UTI?
Cystitis = cephalexin
Pyelonephritis = cephalexin or ceftriaxone
2nd option = SMX-TMP
**only changes are dosage
3-11yrs = 12.5 mg
12 -18yrs = 25 mg
When do you usually have to give ceftriaxone over cephalexin in UTIs?
If the kid wont take oral cephalexin
- have to give IM ceftriaxone
What are second-line therapies that are only used in resistant/refractory UTIs in children?
Cystitis = nitrofurantoin or cefixime
Pyelonephritis = cefixime
can also give ciprofloxacin at any point, however FDA warning = decreased growth and increased risk fo tendon ruptures (so last line)
dont give nitrofurantoin to pregnant adolescents or patients with pyelonephritis
Vesicoureteral Reflux (VUR)
**Most common urinary tract abnormality in children
congenial condition in which the normal value mechanism at the UV is impaired
- causes reflux of urine in the bladder into the ureter or kidneys
- very strong genetic component
Rates = 1-3% in healthy kids; 30-50% in children who have UTIs
Higher the grade = higher the renal scarring risks
Treatment of VUR
Prophylaxis a management for children at high risks of renal injuries (<1yr)
- also if febrile UTIs occur at any point
Posterior urethral valves (PUV)
** most common cause of severe obstructive uropathy in young children (almost always males)**
Urethral valves appear leaflet like and fan dismally from the prostatic urethra to the external urinalysis sphincter (essentially back flows urine when kids try to pee)
- *30% will experience end-stage renal disease of chronic renal insufficiency**
- 50% will experience VUR
Shows mild-major hydronephrosis on imaging
- also symptoms= frequent UTIs, inability to void or pee
must get VCUG to diagnosis
Acute scrotum/testicular torsion
- *is a urological surgical emergency until proven otherwise**
- MUST rule out torsion of the spermatic cord in males (causes ischemia of testies with 4-6hrs if not corrected)
- *testicular torsion is the most common cause of severe scrotal pain in males >12yrs
- caused by inadequate fixation of testies
- requires immediate surgery
- shows a “bell-clapper” deformity
Symptoms:
- acute onset or pain and swelling in scrotum
- dysuria/fever may signal infection as well
- previous UTIs and any trauma at all in history is important to get
What is the time frame of a testicular torsion where irreversible loss of spermatogenesis occurs?
4-6hrs
- testicle will still live but cant produce sperm
What are the results of BP readings in adolescents > or equal to 13 yrs old
Normal BP = <120/<80
Elevated BP = 120-129/<80
Stage 1 HTN = 130-139/80-89
Stage 2 HTN = >140/90
What is the #1 sign for coarctation of the aorta in a child with HTN?
Gradient HTN between upper and lower body BPs:
- upper extremity = HTN
- lower extremity = low BP
