Lecture 5 A cute kid knee injury (AKI) Flashcards
AKI is characterized as an increase in ____ and ____ serum concentration. This occurs due to a decreased ___
creatinine, BUN;
GFR
Creatinine is a breakdown product of ____ in ____ and is usually produced at a constant rate in body, depending on ____
creatine phosphate, muscle;
muscle mass
3 characteristics of creatinine clearance that make it used to calculate GFR:
freely ____;
neither ____ nor ____
filtered;
reasbosrbed nor secreted
3 general categories of renal failure
pre-renal, intrinsic, postrenal
2 most common causes of renal failure (in notes)
pre-renal or acute tubular necrosis;
post renal is least common
death is most commonly caused in acute renal failure because of ____ or ____ complications
infection, cardiorespiratory
normal serum creatinine is less than _____. normal BUN is between ___ and ____
*according to FA
1.2, 7-18 mg/dL
decreased GFR = ____ urine production
decreased (ie oliguria)
Pre-renal:
due to decreased ____. this causes activation of the ____ in an attempt to conserve volume
renal blood flow;
RAAS (renin ang aldost system)
creatinine vs BUN:
which is usually reabsorbed somewhat?
BUN is;
creatine is not
what is the normal Cr : BUN ratio?
15-20:1
Pre-renal azotemia can be caused by ____ ____ depletion or decreased ____ circulating volume to the kidneys ie CHF, cirrhosis, hypotension
intravascular volume;
effective
Angiotensin II normally ____ the ____ arteriole. Prostaglandin E2 normally ____ the ____ arteriole. Both of these cause a ____ in GFR
vasoconstricts, efferent;
vasodilates afferent;
increase
which 2 general drug classes impair renal blood flow?
ACE inhibitors (inhibit efferent vasoconstriction); NSAIDS (inhibit afferent vasodilation)
pre-renal azotemia:
Na/H2O and BUN are ____ by the kidney in an attempt to conserve volume. Creatinine is ____. What happens to the BUN/Cr ratio?
conserved (ie absorbed);
not (ie excreted);
increases ie greater than 20
Pre-renal azotemia:
is urine osmolality high or low?
Is urine Na+ high or low?
Is FENa (Fracitonal excretion of Na) high or low?
high (ie greater than 500)
low (less than 20) due to reabsorption
low (less than 1%)
equation for FENa
(urine Na/serum Na) divided by (urine Cr/Serum Cr)
4 categories of intrinsic renal failure
tubular, glomerular, interstitial, vascular
acute tubular necrosis (ATN) is caused by ___ or ____
ischemia, toxins
3 phases of ATN:
which phase has concern of hypovolemia from polydipsia?
Which phase has the lowest urine output?
inciting event, maintenance, recovery
highest urine = recovery phase
lowest urine = maintenance phase
key finding in urine of ATN?
granular muddy brown casts (dead tubular cells)
which endoegnous toxin causes ATN typically?
2 exogenous toxins mentioned in notes (and FA)
myoglobinuria (From crush injury);
radiocontrast dye, aminoglycosides
which 2 nephritic syndromes can cause AKI?
acute post strep glomerulonephritis;
rapidly progressive glomerulonephritis (RPGN)
RPGN can be a primary disorder or can be secondary to systemic disease such as ____ vessel vasculitis or _____ (An auto-immune disease)
small (eg wegeners);
SLE
Under LM, RPGN is described as ____ shaped.
Acute post-strep GN is described as ____ and ___cellular
crescent moon;
enlarged, hyper
intrinsic renal disease:
is reabsorption of BUN impaired or relatively normal?
what does the BUN/Cr look like?
impaired;
decreased ie less than 15 (aren’t reabsorbing BUN or Cr)
intrinsic renal disease:
urine osmolality is low or high?
what about urine Na?
FENa?
low ie less than 350
high ie more than 40
high ie more than 2%
post-renal azotemia is due to outflow obstruction, such as ____, _____, neoplasia, congenital probs
stones, BPH
post renal AKI occurs only with _____ ____
bilateral obstruction
____ detected on renal ultrasound is the major signal that obstruction is present
hydronephrosis
volume-overloaded patient is treated with ____
volume-depleted patient is resuscitated with ____
lasix;
saline
post-renal azotemia:
early, increased tubular ____ causes resoprtion of BUN. late, increased tubular ____ causes excretion (ie no absorb)
pressure;
damage
