Renal Flashcards
Prerenal AKI versus Intrinsic AKI:
urine sodium
Prerenal: low <20
Intrinsic: high >40
Prerenal AKI versus Intrinsic AKI:
FENa
Prerenal: FENa <1%
Intrinsic: FENa >1-2%
Prerenal AKI versus Intrinsic AKI:
Urine osmolality
Prerenal: high >500
Intrinsic: low <500
Prerenal AKI versus Intrinsic AKI:
BUN:Cr ratio
Prerenal: high >20:1
Intrinsic: low
Prerenal AKI versus Intrinsic AKI:
specific gravity of urine
Prerenal: low (dilute)
Intrinsic: high (concentrated)
5 stages of CKD
1: GFR >90 with evidence of kidney damage
2: GFR 60-89
3. GFR 30-59
4. GFR 15-29
5. GFR <15
when do symptoms of uremia show up in CKD
Stage 3-5
when do lab values show disease (BUN/Cr) in CKD
Stage 3
when do signs of anemia, acidosis, hyperkalemia, hypocalcemia, hyperphosphatemia show up in CKD
Stage 4
what is the best predictor of disease progression in CKD
proteinuria
what is the best way to test for proteinuria in CKD
Spot albumin:cr ratio
preferred over 24h urine
what factors are taken into account in Cockcroft Gault GFR equation
age
weight
creatinine
gender
how to instruct a patient on CKD diet??
low protein
adequate calories, Ca, and Vit D
limit H2O, Na, K and Phos
what should you suspect if someone with CKD has a skull X-ray showing salt and pepper skull, bony cysts, periosteal erosions?
renal osteodystrophy
what is treatment for renal osteodystrophy
Vit D + Ca
Pt with PKD: what is the test of choice
US
fluid-filled cysts will be seen
name some extrarenal manifestations of PKD
berry aneurysms
hepatic, pancreatic, spleen cysts
MVP
diverticula
MC cause of nephrolithiasis
Ca stone
imaging of choice for nephrolithiasis
helical spiral ct scan
treatment for stone <5mm
fluid, strain urine, pain meds, alpha or ca channel blocker
treatment for stone 5-10mm
fluid, pain meds
lithotripsy or ureteroscopy
treatment for stone >10mm
FLUIDS
if renal function impaired - ureteral stent or percutaneous nephrostomy
what drug can you give for a Ca stone to help
HCTZ
what drug can you give for a uric acid stone to help
allopurinol
DIABETES INSIPIDUS
- urine sodium
- urine output
- urine sp gravity
- serum sodium
DI: urine sodium: LOW urine output: high urine sp gravity: low, dilute serum sodium: HIGH
causes a hypernatremia (which is why patients feel thirsty)
SIADH
- urine sodium
- urine output
- urine sp gravity
- serum sodium
SIADH:
- urine sodium: high
- urine output: low
- urine sp gravity: high, concentrated
- serum sodium: low
describe the mechanism of DI: central and/or nephrogenic
Decreased ADH
(central: can’t produce, nephrogenic: not sensitive)
Leads to kidneys not being able to concentrate urine –> large amounts of dilute urine
describe the mechanism of SIADH
increased ADH –> increased water retention –> dilutional hyponatremia
AND
–> kidneys not being able to dilute urine –> concentrated urine
how to differentiate DI: central from nephrogenic
DDAVP test
Give DDAVP. If central - will have effect and urine will concentrate
how to dx DI
fluid deprivation test
take fluid away - normal urine will concentrate but in DI it won’t
how to treat SIADH (mild vs severe)
water restriction is the mainstay
can give hypertonic IV saline with furosemide if severe or brain bleed
how to treat DI (nephrogenic vs. central)
Central: DDAVP
Nephrogenic: Na + protein restriction, hctz
what happens if you replace volume too fast in HYPOnatremia
central pontine myelinolysis
what happens if you replace volume too fast in HYPERnatremia
pulmonary or cerebral edema
Tx for hyperkalemia
calcium gluconate IV*
also sodium bicarb, D50, Insulin 10u, sodium polystyrene sulfonate
Tx for hypokalemia
Oral K replacement, spironolactone
IV if cardiac abnormalities
Tx for hypercalcemia
Fluids and bisphosphonates
tx for hypocalcemia
IV calcium gluconate or calcium chloride (severe)
oral Ca and Vit D (mild)
Tx for hypermagnesemia
mild IV fluids and furosemide
severe calcium gluconate
Tx for hypomagnesemia
Oral mag oxide at 2x the estimated deficit
IV mag sulfate if severe
Tx for isovolemic hyponatremia
water restriction
tx for hypervolemic hyponatremia
water and salt restriction
tx for hypovolemic hyponatremia
NS
tx for severe isovolemic or hypervolemic hyponatremia
hypertonic saline and lasix
treatment for hypernatremia
PO preferred with hypotonic fluids
pure water, D5W, 1/2NS, 0.2% saline.
