FEN, Acid Base, Renal Flashcards
easy maintenance fluid req for wt >20kg
60cc/hr + 1cc/kg/hr
Maintenance electrolyte requirements, Na, K, Chloride
PSC: 1, 2, 3
Potassium: 1 meq/kg/day
Sodium: 2 meq/kg/day
Chloride: 3 meq/kg/day
Calculating % of dehydration by skin turgor and mucus membranes
- normal/slightly decreased skin turgor
- decreased
- markedly decreased
- cold/dry
normal skin, slightly dry mucus membranes: 3-5%
decreased skin, dry mm 6-10%
markedly decr skin, parched cotton mouth 10-15%
Cold/cry, parched >15%
When does pulse go up and resp go up with % dehydration, and when does orthostatus start
6-10% BP still normal
10-15%: orthostatic
cause of late seizure in child with hypernatremic dehydration?
hypocalcemia
how to correct hypernatremic dehyration?
Calculate 48 hour water req, and give slowly over this time use hypotonic (0.2%NS)
volume of distribution of Na? Calculation
0.6 x body weight
Quick and easy way to look at urine lytes and determine if dehyrated?
UNa < 10!
FeNa to determine dehydration vs renal failure
1% renal failure
Syndrome w/ Incr risk of renal artery stenosis due to renovascular disease?
Williams
possible causes of htn in NF? (4)
- pheo
- CoA
- RAS
- tumor
Clue to renal artery stenosis (4)
- renal asymmery
- acute incr BP
- ARF w/ ACEi
- refractory htn
causes of Renal artery stenosis? (4 etiology)
- fibromuscular dysplasia: string of beads
- syndrome: Williams
- athero
- idiopathic
4 syndromes assoc w/ pheo
- NF
- Von hippel landau
- sturge weber
- MEN2
In child w/ endo syndrome with htn/pheo what are the other things to look for? what is dx?
MEN2
higher risk for thyroid and hperparathyroid Ca
dx in child with HTN, wt loss, hyperglycemia, dilated cardiomyopathy
pheo
Dx steps for pheo
24 urine metanephrines, plasma metanephrines more sens in kids.
If high, check abd MRI/CT and MIBG/octreoscan
nephrotic syndrome mortality?
5%
three top bugs in nephrotic syndrome peritonitis?
- Strep pneumo**
- E. coli
- aseptic
hx of large placenta and massive anasarca
finnish autosomal recessive
dx and cause of death?
congenital nephrotic syndrome
Ecoli sepsis
define microscopic hematuria
> /= 3 RBC/hpf x 2 fresh voided urines
urine pos for blood could mean what? next step?
+ hemoglobin, myoglobin, porphyrins.
Obtain a UA!! (dip can’t tell, UA can)…
UA findings for myoglobinuria, hemoglobinuria
myoglobinuria 1-2 cells and dark urine
hemoglobinuria will have jaundice and anemia, but no hematuria / RBC in urine
5 things to know if you get microscopic hematuria to guide work up? If none present, next step?
Just repeat UA in 2 wks unless: Proteinuria HTN Abd pain Dysuria FH Kidney dz
If Microscopic hematuria repeatedly (persistent hematuria), management should be what next and why?
What else to look for?
Check for hypercalciuria in random urine sample
.look for Urine Ca/Cr > 0.25
-may also see crystals in urine and have abd pain/dysuria even w/o frank stones
Urine Calcium / Creatinine ratio < 0.2-0.25 should prompt what work up / management in microscopic hematuria?
24 urine collection, in which value >4mg/day of total calcium would indicate hypercalciuria, therefore need for renal US to look for stone
Urine Calcium / Cr ratio < 0.2 in eval for microscopic hematuria
should check for UPJ obstruction with renal ultrasound to look for structural abnormalities
Relationship between sickle cell and renal disease?
trait and disease can cause hematuria
consider dx in child w/ microscopic hematuria after injury/trauma
UPJ obstruction (very large kidney)
confirmatory test for suspected UPJ
after hydronephrosis found, get renal scan to show delayed excretion from that kidney, and consider VCUG in opposite kidney b/c risk of VUR
how to dx orthostatic proteinuria
first AM urine should be negative, and subsequent daytime one would be positive
protein / creatinine ratio suggestive of renal disease
Protein / Creatinine > 0.2
scenarios in which proteinuria can be benign (2)
- concentrated urine (high spec grav)
2. alkaline urine
If 24 hr urine protein collection is done, what would lead to renal biopsy
> 8mg/kg/day (halfway to 16 which is nephrotic…)
What is alport syndrome?
X linked dominant d/o w/ b/l sensorineural hearing loss, ocular defects, and renal failure in males
(two kidney planes landing on eyes that you can’t hear)
unilateral flank mass should lead to what, and what should you consider
Multicystic dysplastic kidney disease:
dysplastic kidney, may have oligo prenatally. usu unilateral, 50% with other GU anomalies like UPJ obstrx, VUR, posterior valves, megaureter/duplication *think of this as causing the mass. And need VCUG
multicystic dysplastic kidney disease is associated with what?
hepatic fibrosis / portal htn (autosomal recessive polycystic kidney dz)
two presentations of autosomal recessive polycystic kidney dz (AR)
- neonate w/ bilateral flank masses, oligo
2. older child w/ liver issue and kidney masses, TCP/splenomegaly
which polycystic kidney disease is associated w/ brain thing
-what is it and whats the trm
cerebral aneurysm in adult onset PCKD (autosomal dom)
What is nephronophthisis and what do you need to look for (3 things)
juvenile medullary cystic disease (Aut Rec), polyuria, enuresis, polydipsia, hyposthenuria (can’t concentrate urine)
-assoc w/ short stature, eye problems/retinal disease**, anemia
mass from urethral meatus or round filling defect on IVP causing urinary obstruction and urinary retention?
ureteroceles
Grades of VUR and management?
VUR 1 and 2: periodic cultures, most self resolve
VUR 3: Abx and f/u VCUG, 1/2 resolve
VUR 4-5: surgery needed (moderate dilation of ureter and renal pelvis)
Females: Abx
Normal bladder size (wt)
age (yrs) + 2 (ounces)
newborn with palpable bladder and weak urinary stream.
Treatment and prognosis?
posterior urethral valves, prob: even w/ surgery they can get ESRD w/n 5 yrs!
UTI culture result dx
bugs? (3)
100,000 colonies or >10,000 on cath
three most common bugs: Ecoli, Klebsiella, Enterococcus
prune belly triad (Eagle Barrett syndrome)
- lack of abd muscles
- undesc testes
- GU abnormalities w/ obstrx mostly
lipid issue in nephrotic syndrome
LDL / HDL is high, very high cholesterol
nephrotic syndrome and calcium issue?
low albumin, decreases bound AND AVAILABLE calcium, so you get low Ca
nephrotic syndrome and thyroid?
loss of thyroxine binding globulin, so functional hypothyroidism.
RBC casts suggests what
glomerular disease
3 causes of low complement (C3)
- SLE
- Post-strep
- Membranoproliferative glomerulonephritis
(PMS: not in the mood to complement)
typically black teen male w/ progressive renal failure, not responding to steroids
Tx
focal and segmental glomerulosclerosis.. this sucks
Steroids don’t work, use cyclophos or try ACEi or ARB
If you suspect Minimal change disease, but no response to steroids, consider what?
Then its likely focal segmental glomerulosclerosis
what kidney disease should NOT get steroids, and how do you know not to give… 1st step in management?
membranoproliferative GN b/c they may get severe htn, you don’t give them if they have low C3 (also often an older female). Get Renal Bx instead.
peritonitis complication in minimal change nephrotic syndrome caused by what bugs? (3), mortality?
strep pneumo, ecoli, aseptic (5% mortality)
top three nephrotic syndrome?
- Minimal change
- focal segmental (increasing)
- membranoproliferative
massive anasarca in newborn, large placenta, death by 1 yr from ecoli sepsis, what is dx?
autosomal recessive congenital nephrotic syndrome
tea colored, cola colored, rusty, smoky urine
hypertension
edema
Dx?
post strep GN
Berger dz?
IgA nephropathy
IgA nephropathy causes what sx?
indicator of poor prognosis
hematuria, often after URI
bad prognosis if persistent proteinuria
acid/base d/o in chronic renal failure and type of ca/phos issue?
- metabolic acidosis (decr bicarb production by tubule so acid not excreted)
- secondary hyperparathyroid (high because kidney is bad at getting rid of phosphorous and does get rid of calcium –> high PTH) –> decreased calcitriol leads to decr Ca absorption / incr ca loss)
Tx of common HUS in kids?
SYNSORB pk binds verotoxin in Ecoli o157 strain
define htn in kids?
> 95% x 3!
STage 1: 95% - 99%+5
Stage 2: >99% + 5
treatment of hypercalciuria
thiazide and fluids (thiazide decreases urinary excretion of calcium (remember hyper-GLUC)
% of IgA nephropathy that get chronic renal disease?
15%
htn + prematurity
umbilical cath causing renal injury
htn + joint pain/swelling
SLE / connective tissue d/o
htn + flushing, palp, fever, wt loss
pheo
htn with weakness and muscle cramps
hypo K - hyperaldo problem!
htn + sexual development onset
enzyme def (CAH)
htn with pale color and edema
think renal dz (pallor from poor epo / anemia)
HTN w/ low BP in legs vs arms, decr femoral pulse
Coarct Ao
tx before surgery for pheo
alpha blockade before beta blockade (no unopposed alpha or htn crisis)
2 wk infant normal electrolyte lab values
creat -0.2-0.4, high phosphate, relative acidosis, increased FENA
don’t use ACE i in what htn disease?
RAS b/l!!
diagnosing RAS? (3)
can do a random renin level (best after captopril premed)
can check MRA/CTA
US/Doppler - technique dep
water requirement rule for maintenance / day and /hr/
hour: 4-2-1
day: 100-50-20
fluid/electrolyte fluid for 10kg infant? 40kg child?
0.2% NS + 10 meq KCL x 24h
(1/4NS)
child: D5 1/4NS + 20mEQ KCL
1kg = how many ccs of fluid when calculating % loss (deficit) of fluid
1kg = 1000cc
Calculate fluid deficit of 10kg baby 10% dehydrated
0.10 x 10 x 1000 = 1kg = 1000cc
calculation for serum osmolality and what is normal
2 (Na) + 10 + [BUN/3 + Gluc/18]
Estimate with 2(Na) + 10
Normal 290
electrolyte abnormality causing seizure after hypernatremic dehydration
hypocalcemia
calculate free water deficit / excess
Wt x 0.6 = volume of distribution
(Na level x Vc ) / 140 (nl sodium) = new volume distr
New Vd - normal Vd = excess/deficit
Formula for FeNa
UNa x P Cr / UCr x PNa x 100
3 causes of nongap acidosis?
- Renal loss of bicarb (RTA, carbonic anhydrase inhib)
- GI loss of bicarb (diarrhea)
- acid administration (HCl, parenteral nutrition)
anion gap formula, normal?
Na - (HCO3 + Cl)
normal 8-16
RTA type 1 features
Cannot excrete acid load so never w/ urine pH < 6!
renal stones, can get low K w/ Na salts
prob w/ bicarb admin in acidosis
blood will quickly equilibrate with increased bicarb and incr pCO2, but CSF will not catch up right away and will incr pCO2 w/o concomitant bicarb right away;, causing a low pH in CSF…
if urine pH <6, the diagnosis is NOT what?
RTA 1 (can’t excrete acid)
where is defect in RTA 1
distal tubule where you excrete acid from NH4 production
UNa for prerenal
<20 is the clue for prerenal azotemia
clue for renal azotemia in urine sodium
UNa >30
RTA 1 vs 4
both can acidify urine, but four can have hyperkalemia
two drugs potential use in siadh if fluid rstrx fails
demeclocycline
fludrocortisone
two chemo agents that can cause hyponatremia and how
cylcophos decreases water excretion
vincristine causes siadh
diabetes drug that can cause hyponatremia
chlorpropamide
what is the total body sodium in water tox?
what is the urine concentration of na
normal
high urine Na
what is the total body sodium in pseudohyponatremia (like in high TG)
total body na high (water is high, but volume is low so total na looks low)
low calcium effect on ekg
long qt
low magnesium effect on ekg
long pr or qt
hypokalemia ekg changes
flat T, st depr, pvcs
hyperkalemia ekg changes
peak t, no p, wide qrs, EMD
best replacement fluid for toddlers oral
glucose 2-2.5%
na 60-90 meq
(teens water)
appropriate correction of hypernatremia
slow: no more than 10-12 in 24 hours
for every 1L of maintenance fluid, how much Na, CL, K do you need?
How do you figure out deficit Na?
30mEq Na
20meq K
20 meq Cl
Can figure out deficit electrolytes too by multiplying ECF deficit (60% deficit) x 140meq. (This is the 0.6 volume of distribution for Na!)
