deck 1 Flashcards
most common cause of abdo mass in newborns?
unilateral and less frequently bilateral cystic dysplasia
large placenta associated with which nephrological condition
congenital nephrotic syndrome
severe proteinuria before birth
Common clinical manifestations of renal disease in infants
FTT, lethargy, irritability, recurrent emesis
Cause of hypertension in infants without coarctaton?
most common to be renovascular :
ie) renal venous thrombosis, arterial thrombosis (caused by embolism in patients with VSD or PDA or as a result of UAC) or renal artery stenosis
asphyxia or severe dehydration, sepsis or shock - ATN/aliguric AKI
Hypertension in the older child?
headache, dizziness, recurrent emesis, epistaxis, or visual disturbanes
severe cases: can get CHF, especially if oliguria, impaired renal function or GN
Most common cause of hypertension in the younger child?
1: renal and renal vascular disorders for most cases (school age adnyounger)
in older teens, primary hypertension associated with obesity/metabolic syndrome
Other: look for cafe au lair spots, neurofibromas, thyroid, pulses, bruits
Most common reason for referral to paediatric nephrology
hematuria - can be gross or microscopic Causes (often eliminate on history) - neonatal lines, loop diuretics (can lead to stones), meds (TIN, coagulopathies), CHD - >endocarditis with renal deposits - -
Hematuria or kidney failure with family history
think of PCKD
kidney failure with hearing loss
Alport syndrome
gross hematuria - with or without flank or abdominal pain and absence or cases or significant protein, family history of stones or diet high in salt, dairy or vitamins, what should you think of
hypercalciuria
hematuria in a heathy active adolescent
history of direct or indirect trauma
syndromes associated with acquired GN
HSP
SLE
HUS
Initial labs for a child with suspected renal disorder
failure to grow and important sign
labs: CBC, urinalysis, BUN, Cr, bicarb, AP, calcium, phosphorus, PTH
hematuria and casts, which diagnosis to think of?
glomerulonephritis
What are the advantages and disadvantages of urine dipstick screening?
advantages: sensitive, specific, cost-effective
disadvantage: so sensitive might suspect conditions in healthy kids, may miss renal pathology not associated with hematuria or protenuria
most common causes of hematuria
GN - casts
UTI - positive culture
dipstick is positive for blood but no RBCs on microscopy
myoglobin or hemolysis
asymptomatic hematuria - which urine tests to do
urinalysis, culture, urine Ca/Cr ratio (at minimum, since hypercalciuria is so common here)
True or false - malignancies of the kidney or urinary tract rarely present with isolated hematuria (gross or microscopic)
true - this is unlikely in the absence of other signs such as an abdominal mass
Level of proteinuria in nephrotic syndrome
> 40 mg/m2/hour, >1000mg/m2/day, urine protein to creatinine ratio >2.0
features of HSP
skin - purpuric rash
GI: abdo pain, blooody stools, n/v, increased risk of intussusception
joints: arthralgia/arthritis in 65-85%
renal involvement - 20-60% range of manifestations, can happen at disease onset or months after - can be a range of manifestatios (from microscopic hematuria to GN and everything in between)
main treatment of non steroid responsive nephrotic syndrome
minimal change disease - usually steroid responsive
FSGS - cyclophosphamid, some don’t respond so now we use tacrolimus or cyclosporine a lot more, often add cellcept (mycophenolate mofetil) to the regime, use ARB or ACEi as adjuncts
Most common type of stone in children
calcium oxalate or calcium phosphate uric acid, cystine, struvite calculi hypercalciuria - calcium/cr ratio>0.21 citrate inhibits sone formation - can have low citrate in children with stones lasix - caridac disorders hyperparathyroidism cysteinuria hyperoxaluria defects of purine metabolism destal (type 1) RTA UTIs and obstructive uropathies are also risk factors
Management of stones
pain control, increase hydration, Extracorporeal shock wave lithotripsy, ureteroscopy
predisposing consditions to renal vein thrombosis
volume deplesion
hypercoagulable or hyper viscosity states
indwelling catheters in the renal veins
severe nephrotic syndrome in older chilren
Causes of prenatal hydronephrosis
obstructive or nonobstructive (ie reflux)
most common: UPJ obstruction
posterior urethral valves, VUR, prune belly syndrome, ectopic ureter or ureterocele, megaureter (obstructive and nonobstructive), urethral atresia
What to do for antenatal hydronephrosis work up?
figure 13-3 in secrets
U/S 48-72 hours after birth, if negative then, then repeat U/S at 4-6 weeks of age
if at any point US is hydronephrosis (>7 mm) then do VCUG
Renal abnormalities associated with imperforate anus
high imperforate anus - 50% renal anomalies
unilateral renal agenesis, neurogenic bladder, VUR
renal US and VCUG and monitor for UTI
Different types of renal tubular acidosis
all of them have a normal anion gap metabolic acidosis, hyperchloremic (i think all)
type 1: distal RTA - impairment in acidification of urine. low K, hypercalciuria and low citraturia ->therefore increased stones risk
type 2: proximal - impair bicarb reclamation
low K, Fanconi sx - bicarb in urine, aminoaciduria, low phosphate (pee it out), ricks
type 4: distal hyperkalemic -
labs: high K, peds with obstructive uropathy, tubular unresponsive to all or low aldo
clinical: all have poor growth, polyuria/polydipsia, dehydration (recurrent), vomiting
Treatment of renal tubular acidosis
- improve growth
- correct metabolic bone disease
- prevent nephrolithiasis and nephrocalcinosis
- control underlying disease
alkali therapy - goal for normal HCO3 in all forms
Fanconi syndrome - what do you find in the urine
problem is with abnormal excretion of substances normally absorbed in the proximal tubule :
glucose, phosphate, amino acids, bicarb
serum: low phosphate, metabolic acidosis
Most common cause of falcon syndrome
cystinosis
other causes: lowe oculocerebrorenal syndrome, galactosemia, hereditary fructose intolerance, glycogen storage disease, tyrosenimia, wilson disease, mitochondrial disease
specific gravity of maximal dilute urine
specific gravity of 1.001 and osmolality of 50
of maximally concentrated urine
specific gravity of 1.032 osmolality of 1200
normal concentrated urine (neither dilute nor concentrated)
specific gravity of 1.010 and osmolality of 300
difference between specific gravity and osmolality
specific gravity - determined by density of solute in solution
osmolality : depends on the number of particles in solution and effect on its freezing point
acute interstitial nephritis clinical presentation
inflammation of intersitium and tubules (glomeruli and vessels are okay)
lots of clinical presentations - can be isolated tubule problem (Fanconi), ARF, hypersensivitiy
causes of AIN
abx: penicillin, cephalosporin, sulfonamide, rifanmpin
NSAIDS
diurectcs
types of kidney stones in children - most common
calcium 58%
struvite 25% (more common in europe)
other are cystine, uric acid
most common metabolic cause of paediatric urinary calculi
hypercalciuria - familial idiopathic hypercalciuria
other causes:hypocitraturia (since citrate stops the formation of stone)
increased intestinal calcium absorption (vitamin D excess), renal tubular dysfunction, endocrine abrnomalities (hypothyroidism, adrenocorticoid, hyperparathyroidism), bone metabolism , drugs (diuretics, steroids)other (hypercalcemia, UTI, williams)
definition of hypercalciuria
use the calcium to creatinine ratio (urine) for >7 year old >0.24 (different for different ages)
true or false - calcium oxalate sones are not affected by urine PH
true - they are not affected by urine pH, treatment is thiaizide diuretics - help increase renal calcium reabsorption, decrease the urinary calcium excretion , can add potassium citrate
DON’t restric calcium intake
true or false - calcium phosphate stones may benefit from urinary acidification
true
uric acid stones may respond to alkalization of urine
true
treatment for different size stones
2cm SWL success <50%
surgery - obstruction and staghorn calculi
SWL - does not work well on cystine stones
ureteroscopy - distal urethral stones
when might you use a radionuclide cystogram
has less radiation than VCUG but overall don’t get as good images and not as good evaluation
recommend for : screening of siblings with reflux, myelomeningocele, ongoing evaluation
C3 level in PSGN
low
C3 level in IgA
normal, timelines is close to throat infection (vs strep where it is 7-14 days later)
PSGN type of infection that causes
throat or skin
Potter sequence
lack of u/o in utero->oligohydramnios->fatal pulmonary hypoplasia and flattened facies
organs affected by cystinosis
autosomal recesseive - lysosomal transpotar mutation
cystine intracellular ->fanconi syndrome from tubular damage
thyroid (hypo T)
cornea
pancreas (diabetes)
bad growth
infertility
**different forms, worst is infantile (presents around 1 year old)
urine: increased pH, bicarb, glucose and amino acids
serum cystine normal, urine cystine increased
Treatment: cysteamine - cleaves cysteine plus supportive (lytes, vitamin D, growth hormone, renal transplant) ->does not recur in the new kidney
difference between cysteinuria and cystinosis
cystinuria - cystine stone formation due to tubular cysteine transporter mutation, no direct damage to renal cells
type of hearing loss in Alport disease
progressive, high frequency hearing loss
also get ocular changes
(remember type 4 collagen)
most are X linked dominant
hyertensive urgency
BP >99th percentile with headache or vomiting, but no signs of end organ damagee
may treat with IV or PO meds with close follow up as inpatients or outpatients
hypertensive emergency
BP >99th percentile with end organ effects - encephalopathy, seizure, and/or renal dysfunction
treatment: IV antihypertensive - less than 25% decrease over the first 8 hours, then normalize in the next 1-2 days
Comon meds to treat hypertensive urgency and emergency
hydralazine: direct vasodilator -can cause lupus-like syndrome
nifedipine - calcium channel blocker- rapid drop in BP
nitroprussive NO pathway dilator concerns: cyanide toxicity
assorted beta blockers -beta adrenergic blockage, bradycardia
true or false - renal anomalies commonly associated with bladder extrophy
false - generally the kidneys and ureters and other organs are all normal
managemetn: cover with sterile sderessing and get urology to close it up
timing of orchiopexy for undescended testes
usually until 1 year old (since most will descent on their own)
delayed treatment can lead to infertility
increased risk of malignancy - bringing them down doesn’t decrease the chance of malignancy but does improve the chance of detecting it
conditions with pripaism
sickle cell, leukaemia, spinal cord lesions, PD inhibiting meds
treatment beta agonist or alpha blocker
autosomal dominant kidney disease - what other organs can be affected
brain aneurism
liver cysts
mother of boy with alport syndrome will have what clinical sign
asymptomatic microscopic hematuria
med which causes nephrogenic DI
lithium
when should the C3 get better in post strep GN
within 6-8 weeks, if it persists then worry about ongoing immune complex deposition in glomeruli, suspicious for IgA nephropathy or other vasculits
can get microscopic proteinuria and hematuria up to a year after diagnosis (secrets says 2 years)
to diagnose hypertension, need how many measurements
3 separate measurements over 95th percentile
What is rhabdomyolysis
syndrome arising from loss of integrity of skeletal muscle and release of contents of muscle into the extra cellular fluid
clinical range - from asymptomatic CK rise to acute oliguric ATN and multi organ familure
What percentage of acute kidney injury is caused by rhabdomyolysis
5-20% of cases of acute kidney failure
Mechanisms behind rhabdo
- demand for ATP that is greater than the supply
- increased permeability of plasma membrane
- sustained increments in Ca concentrations
Most common causes of rhabdo
- alcohol abuse
- physical exertion - more likely for people who don’t usually exercise, inadequate hydration, following exertion
- compression due to immobilization
- seizures
- drugs
**often multifactorial
viral infection can predispose to rhabdo
Predisposing factors to rhabdo
- potassium deficiency
- enzyme deficiencies in ATP generationg pathways :
- carnitine palmityl transferase
- deficiency of myophosphhorylase
Medications that can cause rhabdomyolysis
- statins (relatively low with current ones) -
- alcohol - direct and indirect effects -
- drugs: cocaine , amphetamines
- hyperthermia - heat stroke, sepsis, neuroleptic malignant syndrome, malignant hyperthermia
Consequences of rhabdomyolysis
- hyperkalemia - since most are in the muscles and the cellular contents are released by the breakdown of muscle
- hyperphosphatemia
- hypocalcemia (because the high phosphate leads to deposition of calcium phosphate in injured muscle
- hyperuricemia
- hypoalbuminemia (from leakage)
- lactic acidosis (metabolic acidosis with increased anion gap)
How does rhabdomyolysis hurt the kidney
causes pigment nephropathy by:
- release of myoglobin
- ECF depletion
- systemic acidosis/aciduria
role of hyperuricemia is uncertain
renal vasoconstriction, renal cytokine production, cytotoxic effects of heme proteins, cast formation
Clinical features of rhabdomyolysis
may present with features of underlying disease, inciting cause or systemic process
localized symptoms and signs: muscle pain, swelling, stiffness, weakness, bruising, features of a compartment syndrome, neurological deficit (?why?)
True or false - rhabdomyolysis could be diagnosis in an otherwise stable patient with dark urine, decreased urinary output, abnormalities in serum electrolytes, an acid base disorder or an acute decline in kidney function
true - doesn’t always need to present super dramatically so should think of it in patients with all/any of those complaints
What will be the urine dipstick and microscopy results in myoglobinuria?
urine dipstick positive for blood BUT no RBCs on urinalysis
can get proteinuria in 50%
can get low FeNA (especially in early stages of the disease)
true or false - you need to have myoglobin in urine to diagnose rhabdomyolysis?
false - myoglobinuria is transient, don’t need the myoglobin in urine to make the diagnosis
What is the best test to confirm diagnosis of rhabdomyolysis?
CK - since CK peaks within 48 hours after rhabdomyolysis, and with a half-life of 48 hours, CK declines after that in the absence of ongoing muscle damage
High CK, best way to differentiate rhabdo from other myopathic conditions?
CK will decline after 48 hours in rhabdo, won’t do that in other myopathic conditions
generally lesser elevation of CK in rhabdo (1000-10000) vs. >100000 (although it IS possible to get it that high with rhabdo)
What level of CK should make you think of rhabdo as the diagnosis?
some discussion
generally people say 5x greater than nomad, or greater that 500
DDx for high CK; can include cardiac and neuro disorders (mild)
What should a second wave CK make you think of?
compartment syndrome
What will be the BUN/Cr ratio in rhabdomyolysis?
low BUN/Cr ratio
other features are electrolyte abnormalities (high K, high PO4, low Ca, metabolic acidosis with AB), hyperuricemia)
after the rhabdo, the creatinine increases more
Managemet of patient with rhabdomyolysis
- vigorous hydration - isotonic saline ASAP
- expands the ECF,improves the GFR, improves u/o, may diminish the risk of cast nephropathy
IV hydration 1-1.5 L within 1st hour (as much as) *8especially if traumatic - alkalization of urine - reduce the risk of pigment nephropathy - can use 0.45% saline with 75 mmol sodium bicarb
- mannitol - also may help decrease the risk of pigment nephropathy
- improve renal hemodynamics increase urinary flow rate, scavenge reactive oxygen species, decrease the risk of cast formation
bad prognosis in Alport syndrome
- proteinuria
- gross hematuria
- thickened basement membrane on biopsy
alport - type 4 collagen
- ear
- eyes - pathopneumonic finding - anterior lenticonus
- kidney
