AKI Flashcards
KDIGO definition for AKI
stage 1 - crt 1.5-1.9 x baseline or Cr >0.3; UOP < 0.5 ml/kg/h for 6-12 h
stage 2 - crt 2-2.9 x baseline; UOP < 0.5 ml/kg/h for >12 h
stage 3 - crt >3x baseline OR crt>4, OR initiation of HD; UOP <.3 ml/kg/hr for >24 h or anuria >12 h
anuria
no UOP or < 100 ml/24 h
oliguria
100-400 mls/24h
polyuria
> 6L/24 h
nonoliguria
greater than 400 ml/24 h
prerenal AKI tx
1-2 L isotonic fluids for hypovolemia
diuretics for hypervolemia
causes of ATN
ischemia
nephrotoxins (contrast, meds)
most common type of hospital acquired AKI
causes of AIN
infection
drugs - antibiotics (allergic interstitial nephritis)!!!!!! #!
immune disorders
causes of glomerulonephritis
damage to filtering mechanisms (immune complex-mediated)
other causes
vascular AKI causes
large vessels - renal vein thrombosis, renal artery stenosis
small vessels - vasculitis, atheroembolic, malignancy hypotension, thrombotic microangiopathies (HUS, TTP)
ATN diagnostics
BUN:Crt ratio - PRESERVED (10-20:1)
FENa: >1 (when oliguric)
UA - negative protein, negative blood, POSITIVE GRANULAR CASTS (dirty brown), RENAL TUBULAR EPITHELIAL CELLS
RF for contrast-induced AKI
(type of ATN)
renal insufficiency
diabetes
multiple myeloma
high osmolar (ionic) contrast media
contrast medium volume
age
contrast-induced AKI characterstics
onset 24-48 h after exposure
duration 5-7 d
non-oliguric
tx w fluids & prevention! (500-1000 ml of NS before procedure, during, and after)
hold other nephrotoxic agents 2 days before if high risk
ATN treatment
remove offending agent
treat offending cause
maintain renal perfusion
avoid nephrotoxins
diuretics for fluid removal
acute interstitial nephritis
renal lesion that causes a decline in renal function
characterized by an inflammatory infiltrate in the kidney interstitial
think inflammatory, hematuria, blood
classic presentation of AIN
fever , rash, arthralgias, eosinophilia
(ask about new meds)
AIN diagnostics
BUN:Crt <20:1
microscopic hematuria
gallium 67 scan, renal ultrasound
renal biopsy - gold standard
white casts, white cell casts, eosinophils
AIN treatment
supportive tx
dx offending agents
manage underlying condition
consider corticosteroids
nephritic vs nephrotic
nephritic - think blood
(think inflammation, hematuria)
nephrotic - think protein
(severe proteinuria, edema, hyperlipidemia, hypoalbuminemia)
in what syndrome do you see glomerular crescent formation
rapidly progressive glomerulonephritis (RPGN)
rapid decline of GFR in 3 month period
nephrotic syndrome tx
treat underlying cause
reduce BP and cholesterol!
manage edema
nephrotic syndrome s/s
severe proteinuria (>3g) d/t kidney damage, HLD, edema
dyspnea, abd fullness, edema, pleural effusions
glomerulonephritis diagnostics
previous infection????
UA - protein, blood RBCs, RBC casts
BUN:Crt ratio preserved
kidney biopsy diagnostic
glomerulonephritis treatment
treat underlying cause - manage BP?
treat infection
immunosuppression if severe
IgA nephropathy
berger’s disease
most common cause of primary glomerulonephritis
classic presentation - gross hematuria after URI
IgA nephropathy diagnostics
gross hematuria within 12-72 hours of infection (viral URI)
proteinuria
kidney biopsy - positive IgA deposits
IgA nephropathy tx
reduce proteinuria
control HTN
consider prednisone or immunosuppression
may require transplant if severe
post renal causes of AKI
mechanical (BPH, strictures, tumors, etc)
functional (spinal cord disease, neurogenic bladder, diabetic neuropathy)
indications for renal biopsy
unexplained AKI/CKD, acute nephritis syndrome, proteinuria/hematuria, previously identified lesion, systemic disease, suspected
transplant rejection, help guide treatment
CI : bleeding, uncontrolled HTN
FeNa
used to differentiate between prerenal and intrinsic
pre renal <1%
ATN >2
lab findings for AKI
rising creatinine and urea
rising K
decreasing hgb
acidosis
hyponatremia
hypocalcemia
indications for acute dialysis
AEIOU
anuria
oliguria
pulmonary edema
hyper K >6.5
severe academies <7.2
uremic encephalopathy
uremic pericarditis
when to consult/admit for AKI
consult - AKI not reversed after 1/2 weeks (neph), s/s/ of persistent UTI (urologist)
admit - sudden loss of kidney function that cannot be handled op, need for acute intervention
acute pyelonephritis
acute inflammatory disease that involves renal parenchyma and renal pelvis
E. coli most common bacteria
acute pyelonephritis tx
fluids
IV abx 48-72 h, then oral
abx depends on pathogen
CTX
fluoroquinolones
zosyn
nephrolithiasis s/s
renal colic - intermittent back/flank pain with radiation
dysuria, chills, fever, N/V, hematuria
uncomfortable, tachycardia, fever, diaphoresis, CVA tenderness
nephrolithiasis management
<5 mm will usually pass spontaneously
FLUIDS
if obstruction or accompanying infection - need removal (extra-corporal shock wave lithotripsy, percutaneous access and removal, ureteroscopy)
pain mgmt - NSAIDs
alpha blockers/calcium channel blockers x4 weeks to help stone pass
prevent future stones - diet changes (dec protein)
nephrolithiasis
kidney stones
calcium oxalate most common
can cause AKI
first line dx for nephrolithiasis
non contrast spinal CT
hematuria
renal artery stenosis
renal artery and its branches are potential sites for plaque formation, which can lead to ischemic renal disease and HTN
caused by atherosclerosis
if you can’t get their BP under control - think renal artery stenosis
fibromuscular dysplasia
unexplained HTN
can lead to renal artery stenosis
renal artery stenosis s/s
refractory HTN
AKI w initiation of ACE
pulmonary edema
audible abdominal bruit
renal artery stenosis diagnostics
renal angiography
screening via ultrasound or CT
renal artery stenosis mgmt
consider revascularization
control HTN, lipids, DM!
ACE, ARB, CCB, statin
postrenal diagnostics
elevated BUN:creatinine ratio
unremarkable UA
consider renal US/CT for hydronephrosis
