Flashcards in Renal/Genitourinary - Step UP Deck (170):
definition of acute kidney injury
rapid decline in renal function with an increase in serum BUN or Cr (relative = 50% or absolute increase of 0.5-1.0 mg/dL)
MC clinical findings in AKI
weight gain and edema - due to positive water and Na+ balance
elevated BUN and Cr
causes of elevated BUN
catabolic drugs (steroids)
GI/Soft tissue bleeding
dietary protein intake
BUN may be falsely low in..
etiology of prerenal AKI (7)
decrease in systemic arterial blood volume or renal perfusion
- hypotension, 3rd spacing
- renal arterial obstruction
- cirrhosis/hepatorenal syndrome
- NSAIDs, ACE i and cyclosporin
- low albumin states
- urine osmolarity (1)
- urine Na+ (2)
- FE-Na+ (3)
- urine sediment (4)
- BUN/Cr ratio (5)
- urine-plasma Cr ratio (6)
(1) Uosm > 500; s.g. > 1.010 (concentrated)
(2) UNa < 20
(3) FENa < 1%
(4) hyaline casts; scant sediment
(5) BUN/Cr > 20:1
(6) urine-plasma Cr > 40:1
pt presents with muscle pain, weakness and dark urine - what should you suspect?
what can cause rhabdomyolysis?
drugs - cocaine
lab findings in rhabdomyolysis
elevated CPK (usually > 100, 000)
myoglobinuria (positive dipstick w/o RBCs)
Tx of rhabdomyolysis
IV fluids - maintain urine output of > 300 ml/hour until urine neg. for Myoglobin
intrinsic renal failure:
- BUN/Cr ratio (1)
- Urine Na (2)
- FE-Na (3)
- Urine osmolarity (4)
- urine plasma-Cr ratio (5)
- urine sediment (6)
(1) BUN/Cr < 20:1 (usually 10:1)
(2) Urine Na > 40
(3) FE-Na > 2-3%
(4) Uosm < 350
(5) urine plasma-Cr ratio < 20:1
(6) brown pigmented casts, epithelial casts
pt presents with envelope shaped crystals on UA with an increased AG metabolic acidosis - dx?
ethylene glycol poisoning
pt who recently underwent angioplasty develops renal failure and blue discoloration of fingers/toes - dx?
- skin biopsy will show cholesterol crystals
how can you prevent contrast induced nephrotoxicity? (3)
hydration - 1-2L NS 12 hrs before
three basic tests in post-renal failure
1. physical examination - palpate bladder
2. USG - obstruction, hydronephrosis
3. catheter - large volume of urine ; residual volume > 50 ml
causes of post-renal failure
1. BPH - MCC
3. obstructing neoplasm
4. retroperitoneal fibrosis
5. neurogenic bladder
what kind of renal failure does a dipstick positive for protein suggest?
intrinsic renal failure due to glomerular insult
red cell casts
indicate glomerular disease - i.e. GN
broad waxy casts
chronic renal failure
muddy brown, granular casts
acute tubular necrosis
renal parenchymal inflammation
- interstitial nephritis
formula for FE-Na
FEna = 100 x [Una x Pcr / Pna x Ucr]
formula for renal failure index
(Una x Pcr) / Ucr
- > 1% = prerenal failure
- < 1% = ATN
MC mortal complications in early AKI
hyperkalemic cardiac arrest
metabolic complications in AKI
metabolic AG acidosis
how do you monitor fluid balance in AKI?
daily weight measurements - most accurate
when should you order dialysis in AKI?
intractable acidemia, hyperkalemia or volume overload develop
Tx. of prerenal AKI
eliminate any offending agents
give normal saline to restore BP
Tx. of intrinsic AKI
therapy is supportive
may try furosemide to increase urine output
Tx. of postrenal AKI
signs and symptoms associated with accumulation of nitrogenous waste due to impaired renal function; BUN > 60
signs and symptoms of uremia (8)
mental status changes
impaired cellular and humoral immunity
chronic renal insufficiency
renal function is compromised but not failed
serum Cr between 1.5-3.0 mg/dL
CV symptoms in CRF
HTN - secondary to salt and H20 retention
pericarditis - uremic
Neurologic findings in CRF
lethargy, confusion, somnolence, peripheral neuropathy, seizures
P/E findings - weakness, asterixis, hyperreflexia, "Restless legs"
Hematologic findings in CRF
1.normochromic normocytic anemia (def. EPO) Tx. EPO replacement
2. bleeding dysfunction - platelets cant degranulate in uremic envt (Tx. DDVAP)
endocrine disturbances in CRF
hyperphosphatemia --> decreased vit D production --> hypocalcemia --> elevated PTH --> renal osteodystrophy and eventually hyPERcalcemia
in high phosphate states, the phosphate may precipitate with calcium causing vascular calcifications and necrotic skin lesions
what drugs can slow the progression of ESRD?
ACEi - dilate efferent arteriole and control BP
diet in CRF
low protein - 0.7-0.8 g/kg body weight
restrict K+, phosphate and Mg2+ intake
how do you tx. hyperphosphatemia in CRF?
- calcium citrate
- sevelamer/levanthum (esp. when due to vit D intake)
- cinacalcet (mimics effect of Ca2+ on PTH)
what type of replacement therapy should CRF pts be on?
long term oral Calcium and vit D
oral Bicarb if acidotic
when should you treat anemia with EPO?
if Hct < 30 or Hb < 10 mg/dl AFTER iron deficiency has been ruled out and pt w/ symptoms of anemia on dialysis
non-emergent indications for dialysis:
1. symptoms of uremia i.e. NV, bleeding, lethargy, mental status changes, pericarditis
emergency indications for dialysis (5)
1. pulmonary edema
2. refractory HTN emergency
3. refractory hyperkalemia, hypermagnesemia
4. severe metabolic acidosis
5. certain drug overdoses
which drugs are dialyzable?
Mg2+ containing laxatives
"First use" syndrome in dialysis
chest pain, back pain and anaphylaxis (rare) occuring immediately after patient uses a new dialysis machine
complications associated with peritoneal dialysis
peritonitis - cloudy fluid
what should you do if you suspect orthostatic proteinuria in someone?
obtain daytime and nighttime urine samples
- decrease protein in night-time samples
what is orthostatic proteinuria associated with?
nutcracker syndrome - entrapment of Left renal vein b/w aorta and SMA
key features of nephrotic syndrome
proteinuria > 3.5 g/day
hypoalbuminemia --> edema
initial test once proteinuria is detected on urine dipstick
urinalysis --> if UA confirms proteinuria, next step is 24 hr urine collection
how do you test for microalbuminuria?
special dipsticks can detect 30-300 mg/day of protein --> if these are positive, do a radioimmunoassay to confirm
most sensitive and specific test for microalbuminuria
definition of proteinuria
> 150mg/24 hrs
> 3 RBCs/hpf on urinalysis
- persistent if in > 2 samples
microscopic hematuria is more commonly (1) whereas, gross hematuria is more commonly (2)
(1) glomerular origin
(2) nonglomerular or urologic
in adults, gross hematuria is what? unless proven otherwise
malignancy - consider bladder cancer or renal cell carcinoma
what are the initial diagnostic tests in gross hematuria?
1. upper urinary tract CT scan or IVP
2. endoscopic assessment of bladder and urethra
what medications can cause hematuria?
what do you do if you find RBC casts and dysmorphic RBCs on UA? what does this mean?
evaluate for intrinsic renal disease --> likely a glomerular cause
what does it mean if the dipstick if positive for blood but no RBCs can be seen under microscope?
hemoglobinuria or myoglobinuria is present
how do you approach hematuria if U/A and urine culture turn up negative?
1. do a coag study - if +, coagulopath
- if negative proceed to 2) KUB
- if shows stones, tx stones
- if normal, do 3) IVP, CT scan and cytology
classic lab findings in nephritic syndrome
proteinuria < 3 g/day
Tx. of nephrotic syndrome
2) if no effect: add cyclophosphamide or azathioprine
3) ARBs/ACEi can inhibit proteinuria
young child presents with nephrotic syndrome; you note fusion of foot processes on EM - dx? what is this dx associated with?
dx = minimal change disease
- assoc. with Hodgkins and NH lymphomas
Tx. of minimal change disease
excellent response to steroids
what is FSGS associated with?
- common in blacks
- assoc with HIV, obesity and heroin use
what are some causes of membranous GN?
infection - endocarditis, hepB/C, syphilis, malaria
drugs - gold, captopril, penicillamine
young Asian patient presents to you because she noticed blood in her urine; she recently had an URI
IgA nephropathy aka. Berger's disease
young boy is brought in bc his mother noticed he couldnt hear properly (high frequency sounds especially); she also said his pee looks red - dx?
consider Alport's disease - XL or AR
-hematuria, proteinuria and sensorineural hearing loss w/o deafness
what is essential for dx. of lupus nephritis?
biopsy - guides tx
- sclerosis = no tx
- proliferative = steroids + mycophenolate
what is membranoproliferative GN associated with?
Hep. C infection, cryoglobulinemia
Hep C patient presents with renal dz, joint pain, neuropathy and purpuric skin lesions; you find he has elevated ESR and low complement - dx? tx?
Tx. IFN and ribavirin
Tx. of membranoproliferative GN
- rarely effective
mother brings young child in because she noticed blood in their urine; upon exam you notice the child has periorbital edema and HTN; history reveals pharyngitis infection 2 weeks ago - what should you be considering?
what additional tests may help with your suspicion of post-streptococcal GN
elevated antistreptolysin O and antihyaluronic acid (AHT)
- kidney biopsy: humps on EM and subepithelial humps (usually not needed)
tx. of post-streptococcal GN
supportive - usually self limited dz
Tx. of Goodpasture's disease
plasmaphoresis - removes circulating ab's
cyclophosphamide and steroids
HIV pt presents with heavy proteinuria and rapid development of renal failure; you do a biopsy and find collapsing FSGS
Tx. HIV nephropathy
patient presents to you with oliguria and fever; you notice he has a rash and on CBC, there is eosinophillia- what should you consider?
acute interstitial nephritis
main cause of acute interstitial nephritis
acute allergic reaction to medication
what diagnostic tests should you do in suspected cases of acute interstitial nephritis?
renal function tests
Tx of AIN
removal of offending agent
- if sx. worsen, steroids may help
pt on chronic pain tx. with NSAIDs presents with sudden onset flank pain, fever, pyuria and hematuria; there are no organisms on culture
think of renal papillary necrosis
how can you confirm diagnosis of renal papillary necrosis
CT scan - bumpy contours in renal pelvis where papillae sloughed off
defect in type 1 RTA (distal)
defect in ability to secrete H+ at the distal tubule (new HCO3- cannot be generated) - results in inability to acidify urine
characteristic findings in type 1 RTA (3)
increased excretion of ions:
- decreased ECF volume
- renal stones/nephrocalcinosis (increased Ca2+ and phosphate excretion into alkaline urine)
Tx. for Type 1 RTA
1. correct acidosis with NaHCO3
2. give phosphate salts (promote excretion of titratable acid)
3. K+ citrate - replaces K+ and HCO3-
urine pH in type 1 RTA
cannot be lowered below 6 - therefore, urine pH > 6
defect in Type 2 RTA (proximal)
inability to reabsorb the HCO3- at the proximal tubule resulting in increased excretion of HCO3- in urine; pt also loses Na+ and K+ in urine
how can you diagnose type 2 RTA?
serum HCO3 low (18-20)
presence of HCO3- in urine (alkaline pH)
malabsorption of glucose, phosphate, urate and aa
Tx. of proximal Type 2 RTA (proximal)
1. Na and water restriction - enhances HCO3- reabsorption
2. thiazide diuretics
3. K+ replacement
what causes Type 4 RTA?
any condition that is associated with hypoaldosteronism or increased renal resistance to aldosterone = decreased Na+ absorption and decreased H+/K+ secretion
features of Type 4 RTA
Dx of type 4 RTA
increase in Urine Na+ after salt restriction is diagnostic
Tx. of type 4 RTA
what disease causes decreased intestinal and renal reabsorption of neutral amino acids such as tryptophan resulting in pellagra?
an adult pt presents with intermittent flank pain, HTN, hematuria and a palpable mass on adbominal exam - what should you consider?
adult polycystic kidney disease
what other associated findings or complications can you suspect in a pt with ADPKD?
- intracranial berry aneurysm
- liver cystics
- mitral valve prolapse
- colonic diverticula
what is the confirmatory test for ADPKD?
CF of infantile PKD?
- liver involvement always - portal HTN, cholangitis
- increased kidney size (abdominal distention)
- pulmonary hypoplasia
Dx. of infantile PKD
- oligohydramnios during pregnancy
- USG will show renal cysts in collecting ducts and hepatomegaly w/ dilated bile ducts
what is medullary sponge kidney?
cystic dilation of collecting ducts associated with hyperparathyroidism or parathyroid adenoma
Dx. test for medullary sponge kidney
what features suggest that a cyst is NOT simple and should be aspirated to R/O malignancy?
irregular walls with debris
thickened septae w/in mass
contrast enhanced, multilocular mass
a pt presents to you with suddent onset of HTN manifesting as a headache; on exam you hear an abdominal bruit (continuous murmur in periumbilical area that radiates laterally) - dx? and next step?
suspect renal artery stenosis
- perform renal arteriogram
- if pt has signs of renal failure, do MRI
Tx. of renal artery stenosis
percutaneous transluminal renal angioplasty with stent placment
- if this is not successful, try surgery
- ACEi and CCB may be tried alone or in combination with the above
thickening of glomerular afferent arterioles in pts with long-standing HTN
rapid decrease in renal function and accelerated HTN due to diffuse intrarenal vascular injury resulting from long-standing benign HTN or in a previously undiagnosed pt
CF in malignant nephrosclerosis
1. elevated BP - papilledema, CNS findings
2. renal manifestations
3. microangiopathic hemolytic anemia
MC site of impaction of kidney stones
MC type of kidney stone
calcium phosphate (less common)
causes of calcium stones
decreased urinary citrate
causes of hyperoxaluria
- severe steatorrhea
- small bowel disease
- Crohns IBD
- pyridoxine deficiency
which kinds of stones occur more likely in an acidic pH urine?
uric acid stones
what are the main causes of uric acid stones?
chemotherapy of leukemias/lymphomas
- conditions with high levels of cell destuction
what kind of stones are MC in pts with recurrent-UTIs due to urease-producing organisms such as Proteus, Klebsiella, Seratia etc?
how do struvite stones form?
alkaline environment - urease positive bugs convert urea to ammonia; ammonia then combines with magnesium or phosphate to form stones
which stones are NOT visible on radiograph i.e. are radiolucent?
uric acid stones
which kidney stones are caused by genetic predisposition?
- hexagon shaped crystals
what size of kidney stone usually passes on its own?
< 0.5 cm
a pt presents to you with sudden of colicky flank pain that radiates anteriorly toward his groin; what test do you do first?
after urinalysis, what is the initial imaging test to be done for kidney stones?
KUB plain radiograph
gold standard for diagnosis of kidney stones
spiral CT scan w/o contrast
what test is useful for defining degree of obstruction and commonly used if a pt needs procedural therapy?
what is the procedure of choice for diagnosing a kidney stone in pts who cannot receive radiation?
indications for admitting a pt with a renal stone to hospital
1. pain not controlled with oral meds
2. anuria - pts with one kidney
3. renal colic plus UTI and/or fever
4. large stone > 1 cm
what is the best tx. approach for someone with their first stone?
hydration and observation
MC used surgery method for renal stone removal
- best for stones > 5 mm and < 2 cm
what kind of removal method is best for renal stones > 2 cm if lithotripsy fails?
dietary measures to prevent recurrences of kidney stones
high fluid intake > 3 L/day
restrict Na+, protein and oxalate
normal calcium intake
what is the first test you should do in suspected urinary obstruction?
gold standard test for dx. urinary obstruction
- contraindicated in prengnacy, allergy to contrast or renal failure
what do you do if a patient has an acute urinary obstruction AND a UTI?
emergency diagnostic tests - USG or IVP
RFs for prostate cancer
age - most impt
high fat diet
positive family history
exposure to herbicides/pesticides
an elderly man presents with difficulties in urination and low back pain - what should you consider?
what is the next step in a patient with an abnormal DRE?
transrectal USG with biopsy
indications for transrectal USG with prostate biopsy
PSA > 10 ng/dL
PSA velocity > 0.75/year
what other conditions may increase PSA levels?
Tx of localized prostatic cancer
when is it ok to "watch and wait" prostate cancer
older men (< 10 yrs life expectancy) who are asymptomatic
MC complications of prostatectomy
tx. for locally invasive prostate cancer
radiation therapy plus androgen deprivation
Tx. of metastatic disease
want to reduce the amt of testosterone with any of the following: orchiectomy, antiandrogens, LHRH agonists or GnRH antagonists
where does prostate cancer commonly metastasize to?
long bones of legs
RFs for renal carcinoma
chronic dialysis - multicystic kidney dz
exposure to heavy metals - mercury, cadmium
pt presents with hematuria, abdominal mass and flank pain - what should you consider?
paraneoplastic syndromes caused by renal cell ca.
anemia/erythrocytosis - EPO
hypercalcemia - PTHrP
HTN - renin
Cushing's - cortisol
a pt presents with a left sided scrotal varice that fails to empty when pt is recumbent - what should you consider?
renal cell ca. that has obstructed the renal vein and drainage of gonadal vein
optimal test for diagnosis and staging of renal cell ca.
CT scan w/ and w/o contrast
Tx. for renal cell ca.
radical nephrectomy and adrenal gland, incl. Gerota's fascia with excision of nodal tissue along the renal hilum
MC type of genitourinary tumor
bladder cancer - transitional cell ca.
RFs for bladder ca.
industrial carcinogens - aniline dye, azo dye
long term cyclophosphamide tx
classic presentation of bladder ca.
definitive test of bladder cancer.
cystoscopy with biopsy
what imaging test can you do in bladder cancer to determine staging?
CXR and CT scan
what is the initial test for localizing a testicular tumor?
B-hCG is elevated in which testicular tumors?
AFP is elevated in which testicular tumors?
Tx of testicular cancer
after suspected with USG, testicle should be removed surgically to confirm diagnosis (inguinal approach)
a young man with a firm, painless testicular mass is presumed to have what? until proven otherwise?
what is penile cancer associated with?
lack of circumcision
HSV and HPV 18 infections
young male presents with acute severe testicular pain, swollen and tender scrotum and an elevated testicle - dx?
testicular torsion - surgical emergency
tx. of testicular torsion
surgical detorsion and orchiopexy to scrotum (do this bilaterally to prevent recurrence) --> should be done within 6 hours to maintain viability
a young male presents with a swollen tender testicle, a scrotal mass and fever/chills - dx?