Nephro guest lecture Flashcards
What is important renal anatomy
L renal vein is longer
R kidney is lower
Kidneys are retroperitoneal (not held by mesentary)
What is the safest and easiest way to look at kidneys
US (best for obstructive disease): renal for proximal-ureter, pelvic for distal
Doppler US: vascular flow in RAS, RVT
*US is less sensitive for renal masses
What is gold standard imaging for renal stones
CT
also used to evaluate tumors and diagnosing RVT
-avoid contrast if possible (nephrotoxic)
What primary imaging is preferred in kids
Radionuclide studies- less radiation than a CT
-can eval obstructive or not, hydronephrosis, and renal function
What is gold standard for RVT evaluation
MRI (also for renal masses)
What happens if you give gandolinium to someone in renal failure (GFR <30)
Nephrogenic system fibrosis: thick skin of trunk and extremities- fibrosis of dermis, muscle, fascia, lung, and heart
When would you use renal arteriography/venography
artery/vein occlusions
polyarteritis nodosa
(but not used often bc more invasive than CT/MRI)
What is an IV pyelogram used for
recurrent stones- tells you where the stone is, size and shape of kidney
but not really used bc of radiation and contrast
What are indications for a renal biopsy
Nephrotic/Nephritic syndrome
SLE
idiopathic ARF
What are contraindications to a renal biopsy
glomerular hematuria
mild proteinuria
What are the types of biopsies
open renal
transjugular
percutaneous (MC, but local anesthesia)
What can go wrong with a kidney biopsy
Page kidney (bleeding under the capsule causing increased pressure)
What is hydronephrosis
edema of collecting system (associated with stones)
What are Sx of hydronephrosis
Asymptomatic
If obstructed: pain, +/- change in UO (relieved by stent)
What are obstructive etiologies of hydronephrosis
GI/Gyn masses
stones
BPH (obstructed urine flow)
What imaging should you get if you suspect obstructive hydronephrosis
US- obstruction will look white (radiopaque)
If US not indicative, get a CT
What are non-obstructive causes of hydronephrosis
Large diuresis (diabetes insipidus) distends intrarenal collecting system
What is Acute Kidney Injury
Abrupt decrease in GFR (usu. reversible)- <48 hrs
What is Acute renal failure
Decrease in GFR and UOP (<5ml for >6hr)
Increased urea and creatinine (SrCr increase >50%// Cr increase >0.3 in 48 hr)
Explain RIFLE
Defines the severity of AKI; Risk, Injury, Failure, Loss, ESRD
Risk for dysfxn if GFR decreases >25%, or UOP decreases <0.5 for 6 hrs
Injury if GFR decreases >50%, or UOP decreases <0.5 for 12 hrs
Failure if GFR decreases >75%, or UOP decreases <0.5 for 24 hrs
Loss of kidney fxn if >4 weeks
ESR if >3 months
What can cause AKI/ARF
*pre-renal AKI (MC)
Intrinsic AKI
Post renal AKI
What are Pre-renal causes of AKI
hypoperfusion; decrease in intravascular volume, change in vascular resistance, low cardiac output
Low renal perfusion + low cardiac output cause
increased BUN:Cr ratio (> 20:1 )
How do you treat hypoperfusion (pre-renal)
maintain Euvolemia and avoid nephrotoxic agents (NSAID, ACE-I, Digoxin)
What are intrinsic causes of AKI
Acute Tubular Necrosis *
acute interstitial nephrosis
glomerular nephrosis
vascular
What is acute tubular necrosis
Tubular damage due to ischemia or nephrotoxins (ampho B, vanco, contrast) causing prolonged hypotension and hypoxemia
How do you treat ATN
avoid volume overload
avoid K
protein restriction
+/- diuretics
What do you do if someone with ATN needs imaging
give N-acetylcystein + Bicarb to renally protect them
What is Acute Interstitial nephrosis
Inflammatory response leading to edema and tubular damage
2/2 Nephrotoxic drugs, strep, CMV, RMSF, AI (SLE, sjogrens, sarcoidosis)
How do you diagnose and treat AIN
US: eosinophilia
good prognosis with steroids +/- dialysis
What is Glomerulonephritis
Immune complex deposits (IgA nephropathy, good pasteur’s, post infectious strep, Wegener’s)
How do you diagnose and treat Glomerulonephritis
US: RBC casts (coca cola pee) d/t bleeding kidneys
Treat with steroids or plasma exchange
What are post-renal causes of AKI
obstructions (BPH, urolithiasis, cancer, bladder dysfunction, anticholinergic drugs) all leading to lower Abd pain
How do you diagnose and treat post renal AKI
US and increased BUN:Cr
Treat by decreasing pressure w/ cath, stent, or surgery
How do you manage ARF/AKI
identify and reverse source
+/- short term dialysis
What are indications for hemodialysis
Weight (gain) Edema (fluid overload) Messed up electrolytes decreased UOP unresponsive acidosis (pH <7.1)
When someone is on hemodialysis what do they need to be cautious about
K+ containing foods (tomatoes, potatoes)
What are the ways you can get hemodialysis
Fistula
graft
tunneled line
What happens if an AKI kidney is put into a new body
it will function like normal! AKI is reversible
At what stage of kidney disease do we develop ESRD
Stage 5; GFR <15, or on dialysis
What does GFR measure
Degree of impairment, varies by age, gender, and body size
measured by MDRD; modification of diet in renal disease
What is creatinine
Waste product of creatinine phosphate from muscle breakdown
dependent on muscle mass- it passes thru muscle and kidneys
What is Azotemia
Nitrogen in the blood that occurs when kidneys cant clear metabolites d/t renal parenchymal damage, leads to uremia
How is azotemia measured
BUN:Cr (uremia)
What is uremia
Urea in the blood
urea is normally made by the liver and peed out
in stage 3-5 of CKD, urea cant be processed and excreted by kidneys so it gets into blood
What are Sx of uremia
Malaise N/V dyspnea cramping bleeding Sz cardiac arrest -HTN, muscle waisting, ecchymosis, Kussmaul breathing
What test diagnoses CKD
GFR!!
also increased BUN:Cr, proteinuria, microalbuminuria
(consider a renal biopsy)
How do you treat CKD
ACE/ARB (slow progress), Epogen, Fe, antiplatelets (get Hgb to 11-12)
low protein diet
fluid restrict
Calcium/vitamin D
What is hypervolemia
low Na and increased volume (CHF, ESRD, ESLD, nephrotic syndrome)
decreased Hgb/Hct
How do you treat hypervolemia
fluid restrict, consider diuretics or short term dialysis
What is hypovolemia
volume loss from ECF > intake (2/2 GI tract, kidneys, 3 spacing, skin/injured tissues)
high Hgb/Hct, high urea, low Na
If Na and volume both low, GI or renal source
How do you treat hypovolemia
Isotonic IVF (but dont correct too fast, can cause central pontine myelinolysis)
What are some causes of CKD/ESRD
PKD DM GMN HTN SLE Nephrolithiasis
What is PKD
many bilateral cysts= decreased renal mass= decreased renal function Autosomal dominant (FHx) associated with hepatic and pancreatic cysts
What are symptoms of PKD
hematuria, infection, stones, nocturia, pain (if rupture)
leads to weight loss, early satiety, N/V
How do you diagnose and treat PKD
US is choice (but CT shows it better)
Tx: pain management, ACE/ARB, aggressive Abx is symptomatic
What are diabetic glucose levels
fasting glucose: >126
HgbA1C: >6.5
What are complications of DM
retinopathy
nephropathy
neuropathy
increased risk of CV disease and stroke
Explain metformin and kidney CT scans
Avoid Metformin if Cr >1.4 (w) or >1.5 (m)
Hold metformin the day of the scan and 2 days after
–to avoid lactic acidosis
Avoid metformin in decompensated HF, liver failure, or alcohol use
What is RAS
usually d/t atherosclerosis
diagnose with renal angiogram* (or doppler)
treat with angioplasty, +/- stenting
What is renal secondary HTN
2 episodes of SBP >140, or DBP >90
How do you treat renal secondary HTN
lifestyle modifications then meds (thiazide, ACE, CCB)
What is SLE
autoimmune d/o where autoantibodies attack healthy tissue, leading to nephritis and proteinuria
+ ANA
MC in young females and african americans
What are the types of renal stones
Calcium (radiopaque)
Uric acid (radiolucent)
Cystine (radiolucent)
Struvite (radiopaque)
Struvite stones are made of
Calcium
Magnesium
Ammonia (from UTI/catheters)
How is nephritic syndrome treated
Diuretics
salt and water restriction
dialysis
What is the prognosis of renal failure
most AKI recover (early recognition is key!)
OR, CKD/ESRD
What reversible processes can decrease renal function
Hypovolemia
Infection
NSAID’s
ACE-I
Major causes of death in dialysis patients include
- CV disease
- Infection (Staph aureus)
- Withdrawal
