BRS Renal Flashcards
Total body fluid requirements =
maintenance fluid needs +
prior loss +
ongoing losses
Two types of fluid losses
sensible (urine, etc. measurable)
insensible (sweat, skin etc…not measurable)
Maintenance fluid requirements for children
1500 mL/m^2/day or..... 100ml/kg/day for first 10 kg 50ml/kg/day for second 10 kg 20 ml/kg/day for any additional 10 kg
How much should maintenance fluids be increased during fever?
12% for every degree increase in temp above 38
Normal sodium range + relevance to dehydration
130-150
above= hypernatremic dehydration, correct over 48 hours
below/equal= hypo/isonatremic, correct over 24 hours
Three severities of dehydration
3-5%: mild
7-10%: moderate
12%+: severe
Typical bolus amount
20ml/kg normal saline for all dehydrated patients What
Composition of oral rehydration salts
glucose + electrolytes
coupled cotransport mechanism
Define microscopic hematuria (#)
more than 6 RBCs per HPF
Cause of false negative urine dipsticks
vitamin C
Shape of RBCs from upper vs lower urinary tract
upper: dysmorphic, blebs in membrane
lower: normal biconcave discs
Three hematologic causes of hematuria
sickle cell
thrombocytopenia
thrombosis
Four glomerular diseases leading to hematuria
- bergers
- HSP
- PSGN
- Alports
Proteinuria level considered pathologic
more than 100mg/m^2/day
What causes incorrect measures of protein in urine
high concentration = false +
low concentration = false -
Typical test for urine protein in children + normal levels
TP/CR
6-24 months, less than 0.5 normal
2+ years, less than 0.2 normal
Dipstick + for blood but no RBS on U/A… cause?
hemoglobinuria, myoglobinuria
Orthostatic proteinuria, protein is excreted when?
when upright but not supine
Cause of glomerular proteinuria
increased permeability of the glomerular capillaries
Cause of tubular proteinuria
decreased reabsorption due to injury
Marker for tubular vs glomerular proteinuria
tubular: B(two)macroglobulin
glomerular: microalbumin
Two types of glomerulonephritis
primary vs secondary
Signs of acute nephritic syndrome
- gross hematuria
- hypertension
- fluid overload
Signs of acute nephrotic syndrome
- heavy proteinuria
- hypercholesterolemia
- edema
Labs for glomerulonephritis (6)
- U/A
- TP/CR
- blood chem
- complement levels
- antibodies (DNAB, ASO)
- IgA
How long after GAS infection does PSGN onset?
8-14 days
PSGN assc labs
- low complement
- ASO+ 90%, ADB + for all
When is renal biopsy indicated for PSGN
within 8 weeks if kidney function isn’t normalized
Most common acute glomerulonephritis worldwide? chronic?
acute: PSGN
chronic: IgA Nephropathy (Bergers)
Recurrent bouts of gross hematuria assc with URI:
cause
IgA Nephropathy (Bergers)
Histo findings assc with PSGN + Bergers
mesangial cell proliferation + increased mesangial cell matrix for both + IgA deposition in Bergers
Prognosis PSGN vs Bergers
PSGN- usually full recovery
Bergers- 20-40% ESRD
In addition to purpura, abdominal pain, what signs are assc with HSP ?
- arthritis
- hematuria
What type of disease is HSP?
IgA mediated vasculitis
When is renal biopsy indicated for HSP?
heavy or nephrotic range proteinuria
Histo findings assc with MPGN
- lobular mesangial hypercellularity
- thickening of GBM
Prognosis MPGN
almost all = ESRD
Labs assc with MPGN
75% have low complement
Most common cause nephrotic syndrome in US adults?
Membranous Nephropathy
=heavy proteinuria –> renal insufficiency
Definition of nephropathy
heavy proteinuria greater than 50mg/kg/day
In addition to proteinuria, what labs are assc with nephropathy?
- hypoalbuminemia
- hypercholesterolemia
- edema
Most common cause primary nephropathy
minimal change disease
Two systemic diseases that cause nephrotic syndrome
SLE
HSP
Physiologic cause of nephrotic syndrome
loss of normal charge and size glomerular barrier
When does edema occur in nephrotic syndrome?
following URI
Two risks assc with nephrotic syndrome?
thrombosis
infection with encapsulated bacteria
(COD in 5%)
CBC changes assc with nephrotic syndrome?
- elevated hematocrit
- hemoconcentration
Nephrotic syndrome:
biopsy?
only if creatinine clearance is impaired/ corticosteroids don’t work
Treatment of widespread edema in nephrotic syndrome
25% albumin IV
no added salt in diet
steroids
Cause of ESRD in NS
FSGS
Abx treatment for HUS?
NO!
and… abx treatment of hermorrhagic colitis= ^^ risk HUS
E coli strain responsible for HUS ?
0157:H7
Key to pathogenesis in HUS
injury to endothelial cells by shiga toxin
Causes of death in HUS
toxic megacolon
CNS infarctions
Poor prognostic signs in HUS
high WBC count
prolonged oliguria
Alports:
inheritance pattern
defect
XD
type 4 collagen in basement membrane
Three manifestations of alports
cant see
cant pee
cant hear high C
Most common cause of a renal mass in the newborn
multicystic renal dysplasia
Adult vs infantile polycystic kidney diseases
ARPKD (infantile)
ADPKD (adult)
Two organ systems effected by ARPKD in addition to renal:
pulmonary hypoplasia
liver involvement= constant (portal HTN, cirrhosis)
Prognosis of ARPKD/ ADPKD:
most = severe HTN + renal insufficiency and require transplant
Define:
- normal HTN
- significant HTN
- severe HTN
- malignant TN
- normal 90-95th %ile
- significant 95th%ile+
- severe above 99th%ile
- malignant: end organ damage
Most hypertension in childhood is _____ HTN
secondary
Three secondary causes of HTN in newborn
- renal artery embolus/ stenosis
- coarctation
- renal disease
2 most common causes of HTN in kids 1-10
coarctation
renal disease
2 most common causes of HTN in adolescents
renal disease
essential
Consequences of chronic HTN in kids
growth retardation
poor school performance
Initial evaluation of HTN in peds
- CBC/BMP/UA/BUNCr/renin
- CXR/RUS
Signs of RTA
- calculi
- weakness/ myalgias
- FTT
- vomiting
Drug that may cause acquired RTA
amphotericin
Classic electrolyte presentation of RTA
hypercholermic acidosis + normal serum anion gap
How to calculate urine anion gap
Na+K-Cl
hypokalemia hypophosphatemia aminoaciduria \+RTA =suggestive of
Fanconis
Defect assc with:
Type 1 vs Type 2 RTA
Type 1= distal= failure to excrete H+
Type 2= proximal= failure to absorb bicarb
Type III RTA defect
variant of type I but = proximal bicarb wasting in babies
Hallmark of Type IV RTA
transient acidosis + hyperkalemia
Treatment of all RTAs
oral alkali
Treatment of Type IV RTA
oral alkali + furosemide
Which type RTA is assc with:
Fanconis
amphotericin/nephrotic syndromes
obstructive uropathy
aldo def
- Fanconis= type II
- amp/nephrotic syndromes (acquire)= Type I
- obstructive/aldo def= Type IV
Type RTA assc with stones
Type I
Define oliguria
less than one ml/kg/hr
Renal failure management
-restore volume
-electrolyte intake to match losses
-protein restriction
+/-dialysis
Disease that manifests SECONDARY TO renal failure
renal osteodystrophy
BUN/Cr and FeNa in prerenal ARF
^^^ BUNCR move than 20
low FeNa less than 1
Renal Tubular ARF assc FeNa + marker
high B2 microglobuin
FENA above 1
ARF due to glomerular damage causes ____ and _____
hematuria and proteinuria
Interstitial nephritis marker
eosinophilia/uria
post renal ARF findings
renal dilation on US
Vascular related ARF findings
decreased renal blood flow on nuclear renal scan
Two types of ureteral obstruction
ureteropelvic
ureterovesical
Cause of bladder outlet obstruction in males
posterior urethral valve obstruction
Absence of rectus muscles + bladder outlet obstruction + cryptorchidism=
prune belly syndrome
Most common newborn abdominal mass
multicystic dysplastic kidney +atretic ureter
Most common anomaly assc with UTIs + inheritance pattern
vesicoureteral reflux =AD
How to Dx VUR
voiding cystourethrogram
Px treatment of VUR
low dose abx to prevent UTI until it is outgrown
Grade 1-2 VUR
1: reflux into distal ureter only
2: reflux into pelvis without dilation
Grade 3-5 VUR
3: into calyces + dilation
4: into calyxes + dilation + clubbing
5: gross dilation of entire collecting system + tortuosity of ureters
Workup for any kid with renal stones
rule out metabolic disorders
What UTI type is assc with stones
proteus
Three common stone components
calcium
oxalate
uric acid
When are UTIs most common in boys?
more common in boys before 6 months
girls after 6 months
Most common pathogenesis of UTI
ascending infection
Sign of pyelo
fever + systemic illness
gold standard dx of UTI
more than 10k colones on catherized sample
any bacteria on suprapubic sample
more than 50k colonies on clean catch
When is imaging needed in case of UTI ?
pyelo
recurrent UTI
all males
girls younger than 4 with cystitis
Two options of treatment for empiric uti
TMP-SMX
cephalexin
Neonate UTI treatment
amp & gent
How to prevent renal scarring in infants
3 months px antibiotics after pyelo episode
