Nephrology Flashcards
what is the gold standard test for diagnosing renovascular disease?
Renal arteriography
Although arteriography is gold standard for diagnosing renovascular disease, what are some better options that are NONINVASIVE?
Duplex Doppler US
Computed Tomographic angiography (CTA)
Magnetic Resonance Angiography (MRA)
What is the risk of performing renal arteriography on a patient with renal dysfunction?
performing arteriography may precipitate atheroembolism
you do workup on a patient with suspected renovascular disease, and initial noninvasive test (US Doppler) is inconclusive. What is the next best option?
renal arteriography
what is the substance used in radiocontrast that can be nephrotoxic to patients with kidney dysfunction?
Gadolinium
noninvasive diagnostic kidney tests are best for _________ disease (proximal, distal, or systemic?)
proximal. Does a poor job of picking up plaque due to FMD
Which noninvasive test provides information on both structure and function of the kidneys?
Duplex Doppler US
preferred over CTA and MRA, because there is no contrast so it is safer!
which diagnostic test for kidney dysfunction still uses gadolinium?
MRA
What is the benefit of using MRA for imaging of the kidneys?
provides excellent view of the PROXIMAL renal artery stenosis
kidney noninvasive imaging ranked from most preferred to least preferred
Doppler US –> CTA –> MRA
what percentage of stenosis in one or both renal arteries is needed to DIAGNOSE renal artery stenosis by CTA/MRA
> 75% (or 50% with post-stenotic dilation)
what percentage of stenosis is needed to diagnose renal artery stenosis via DOPPLER US?
> 60% (peak systolic velocity >200 cm/sec)
Treatment unilateral/bilateral Renal artery stenosis?
ACE-I/ARBs first line (before considering revascularization)
Which is favored in percutaneous transluminal renal angioplasty (PTRA)?
STENT is preferred over surgery
only perform surgery in pt who have complex anatomic lesions where stenting is not possible
what is the limitation of management WITHOUT revascularization in FMD?
stenosis and kidney dysfunction may progress despite good BP control
treatment for FMD?
ACE-I/ARBs are first line
Is PTRA with stenting preferred as FMD treatment?
PTRA is preferred over surgery, but WITHOUT STENT PLACEMENT!
do you place a stent via PTRA in FMD?
NO!
True or false: start a patient w/ FMD on a statin with their antihypertensives
FALSE! - these patients do not have atherosclerosis in their lumen, they have connective tissue replacing normal epithelium, so statins WONT HELP
How often does BP and serum creatinine levels need to be monitored in patients with FMD who are only treated with medication?
every 3 months
if stabilizes, then annually.
what is the new ACC/AHA target BP for all patients?
130/80
New guidelines for treating patient with 130-139/80 BP?
nonpharmacologic therapy
“elevated”
what is the disorder called when a stenotic lesion in the renal artery increases the SVR, increasing BP?
Renal artery stenosis
what are the 2 major causes of renal artery stenosis?
Atherosclerosis
Fibromuscular dysplasia
Which is more common, unilateral renal artery stenosis or bilateral stenosis?
unilateral
True or false: patients with renal artery stenosis are assumed to have coronary artery disease until proven otherwise
TRUE
treat like you would CAD:
statin, ASA, BP control, smoking cessation
Atherosclerosis in the renal arteries is commonly distal or proximal?
proximal
This renal disorder is considered non-inflammatory, non-atherosclerotic disorder that leads to arterial stenosis, occlusion, dissection
Fibromuscular dysplasia (FMD)
you may see a string of beads on imaging with this renal disorder
FMD
young patient is having recurrent episodes of flash pulmonary edema and an acute rise in serum creatinine of >30%, AFTER initiating an ACE-I. what is your most likely dx?
Renovascular disease, most likely FMD.
Considering a CKD diagnosis requires decreased kidney function for how long?
> 3 months
What is the most frequently assessed marker of kidney damage?
Albuminuria
what imaging abnormalities might you find while looking at the kidneys of someone with CKD?
hydronephrosis, echogenic kidneys, polycystic kidneys
What is used to measure decreased kidney function?
GFR/eGFR
Threshold <60
The G-stages of CKD begin to accompany SYMPTOMATIC disease at which stage?
G3a (<60)
True or false: those with CKD should also be assumed to have Coronary artery disease until proven otherwise
TRUE
How to treat volume overload in someone with CKD
sodium restriction
Loop diuretics
what is the caution regarding handling a CKD patient with metabolic acidosis?
bicarb supplements need to include CLOSE monitoring of volume status.
How do you handle mineral and bone disorders in a CKD patient?
phosphate restriction and administration of CALCITROL
how to manage a CKD patient with HTN
begin with ACE/ARB + diuretic + thiazide diuretic.
Then add Loop diuretic for volume overload
is it ok to add a loop diuretic to the thiazide?
YES - they have an additive effect and it is safe
True or False: anemia of CKD is normocytic and normochromic
True
What are the characteristics of RBCs in someone with CKD
Reduced production of erythropoietin and shortened RBC survival
True or false: the triglycerides in a CKD patient are NORMAL while the total cholesterol is HIGH
FALSE - hypertriglyceridemia, and normal total cholesterol
Which vaccines should you give a patient with CKD?
influenza
pneumococcal
Hep B
In AKI, what is the hallmark amount you will see creatinine increase?
1-1.5 mg/dL daily
patient with suspected AKI is experiencing a 2.2-fold increase in serum creatinine, and you check the time frame, noting that it has been 16 hours since admission. What stage AKI are you suspecting?
stage 2
what is the 3rd leading cause of new-onset AKI in hospitalized patients?
Radiographic contrast media
most common cause of post-renal AKI in MEN?
BPH
post renal is likely due to obstruction
Your hospitalized patient is on Vancomycin, is a diabetic, and needs repeat imaging for further assessment of kidney function. You notice she has had radiographic contrast media 20 hours ago. Should you undergo the imaging with contrast?
NO! assess patient’s risk for AKI as radiocontrast is directly nephrotoxic
diabetes + kidney dysfunction are at higher risk for contrast nephropathy
What will serum creatinine levels look like in “abnormal” kidney function?
Elevated - unhealthy kidneys cannot filter creatinine effectively so it gets reabsorbed into the serum
after obtaining a urinalysis, you see “muddy brown casts” on urinalysis. What is your most likely diagnosis?
ATN (acute tubular necrosis)
what is the most common cause of AKI?
Pre-renal causes (renal hypoperfusion)
if your diabetic patient absolutely NEEDS the imaging study with the contrast, what do you administer?
1 Liter 0.9% IV saline over 10-12 hours BEFORE AND AFTER contrast is administered
(also tell patient to avoid other nephrotoxic agents the day before and after)
treatment for ATN (acute kidney injury subcategory)
avoid volume overload avoid hyperkalemia Adjust doses that are renally cleared ACUTE DIALYSIS (nephrology referral)
What are the 3 phases of ATN?
initial injury
maintenance (1-3 weeks)
recovery
what do you need to be cautious of after treating Post-renal AKI?
post-obstructive diuresis
monitor volume status so patient isn’t losing too much
Your patient has AKI, and it is suspected that it is post-renal causes. They need to undergo which procedure first?
Bladder catheterization!
DO NOT cath anyone with cancer
What is the imaging study of choice for a patient with suspected post-renal AKI?
Ultrasound
+/- CT scan if needed
What causes 70% of acute interstitial nephritis?
DRUGS (medications!)
NSAIDs penicillin, cephalosporin allopurinol, PPIs
Describe acute interstitial nephritis
interstitium is inflamed, the edema causes cell damage to kidney.
A patient presents with Fever, rash, and arthalgias. What is your FIRST plan of action regarding tests/imaging?
GET A KIDNEY PANEL FIRST!
to assess for acute interstitial nephritis
Pathophysiologic disorder where acute or chronic deterioration of one organ causes acute/chronic deterioration of the other (ex: heart and kidneys)
Cardiorenal syndrome
what are the subtypes of interstitial AKI?
Acute tubular necrosis (ATN)
Acute interstitial Nephritis
Glomerulonephritis
Cardiorenal syndrome
difference between volatile acid and nonvolatile acid
volatile: readily evaporates (carbs and fat)
nonvolatile: must be excreted by kidney (amino acids)
which takes longer, compensation by kidneys or lungs?
kidneys take days (lungs take minutes)
potassium is controlled by ______ at what part of the nephron?
Aldosterone; collecting duct
altered sensorium is commonly seen in patients with ___?
acute kidney injury - build-up of materials causes confusion
what can be seen in labs several days prior to AKI?
platelet dysfunction - you’ll see a steady decline = red flag
“muddy brown casts” on UA is suggestive of what?
Acute tubular necrosis AKI
if patient has fever + rash + arthralgias what are you thinking (kidney-wise)
do a workup! could be intersitital necrosis
