Renal Assessment Flashcards
What is anuria
What is oliguria
What is polyuria
UOP <50-100 ml/day
UOP < 400-500 ml/day
UOP > 3000 ml/day
What is Azotemia
What is uremia
elevated BUN without sx
Elevated BUN with sx (usually nonspecific)
Most cases of AKI are from either
ATN
Prerenal azotemia
what are some causes of prereanl azotemia?
antibiotics
iv contrast
heme pigments
light chains
pre renal azotemia results in what?
activation of RAAS and ADH release
both lead to decreased UOP as a mechanism to resotre ECV
A FeNa <1% is considered what
a FeNa >2% is considered what?
Prerenal azotemia
ATN
Why is the vasa recta susceptible to ischemia?
the renal medulla is a watershed area receiving its blood supply from the vasa recta making it relatively starved of O2
Why do the proximal tubule and mTAL have high metabolic activity?
because of Na reabsorption driven by basolateral membrane Na/K ATPase
In ATN, the GFR decreases due to what two things?
- tubular obstruction from cast formation
- back leak of urine filtrate due to loss of tight junctions
when someone is in pre-renal azotemia for a long enought time, what may develop?
ATN
What drugs cause interstitial nephritis?
Nsaids, abx, PPIs
What is Acute interstitial nephritis?
classic presentation includes fever, rash, arthralgias, peripheral eosinophilia, WBC casts
What is chronic interstitial nephritis
class presentation includes minimal proteinuria, bland urinary sediment, slow renal decline and fibrosis
What are the s/s of AKI?
edema
HTN
decreased urine output
proteinuria
hematuria
SOB
uremia
pericardial friction rub
asterixis
uremic frost
What labs should be ordered for AKI diagnosis?
urinalysis with micro
urine albumin/crt ratio or urine protein/crt ratio
a BUN/crt ratio of 20:1 or more indicates what?
prerenal azotemia or ATN
Renal US showing small kidneys is suggestive of what?
Renal US showing cortical thinning if suggestive of what?
CKD (for both)
What is the purpose of ordering a FeNa or FeUrea?
to differentiate prerenal azotemia from intrinsic renal injury (ATN usually)
If a pt is non-oliguric, then by definition they cannot be
prerenal
In dehydration, why do urea levels go up?
ADH binds to V2 receptors and increases cAMP levels which leads to insertion of AQP and urea transporters
What are some pertinent questions to ask for AKI?
fluid intake
n/v/d
orthostatics
HTN, DM2, CKD
recent abx or new meds
recent IV contrast
urinary retention sx
family hx of kidney disease
What are some s/s of dehydration?
dry mucosa
skin turgor
JVD
What are the indications for dialysis?
(AEIOU)
A-severe Acidosis
E-Electrolyte disturbance
I-Ingestion
O-volume overload
U-Uremia
What is the prognosis of AKI?
depends on severity and duration, underlying conditions, age, and need for hemodialysis
no guaruntee that function will recover
most people recover within 7-21 days
if no recovery after 3 months, pt now has CKD
