Urinalysis
What is the most important indicator of renal disease on urinalysis?
Proteinuria
High BUN:Cr ratio indicates __________ AKI and low indicates ___________ AKI
pre-renal; intrarenal
Hypernatremia is almost always 2/2 what?
free water deficit
What are the two most significant findings on EKG in hypokalemia? Hyperkalemia?
Hypo: U wave and prolonged QT interval
Hyper: peaked T waves, QRS widening
What would you expect to see on ultrasound if postrenal failure/AKI was present?
hydronephrosis
What is the most common testicular tumor?
seminoma
What is leukocyte esterase and what does it indicate? What do nitrites indicate? What do the presence of both indicate?
Leukocyte esterase- enzyme released by leukocytes, signify pyuria
Nitrites- indicate presence of bacteria that convert nitrates to nitrites.
Together- indicate UTI
What is urea? What is indicated by high levels in the blood (elevated BUN)?
Urea is formed in the liver as an end-product of protein metabolism. Elevated BUN indicates inadequate excretion of urea by the kidneys
Through what mechanism do heart failure and cirrhosis lead to hyponatremia?
perceived hypovolemia despite volume overload- fluid is third spaces resulting in ineffective circulating volume which leads to ADH secretion.
If BMP calcium is low, what protein level should be corrected for? What lab should be ordered next?
albumin; ionized calcium
What findings on ultrasound and doppler ultrasound would be suspicious for nephrolithiasis?
hyper echoic areas with acoustic shadow and twinkling artifact on doppler
What is the name of the score used to determine aggressiveness of prostate cancer?
Gleason Score
Elevated urine urobilinogen is most commonly caused by _______ _______ while elevated urine bilirubin is most often caused by _____ _______
hemolytic anemia; liver disease
Creatinine approximates GFR __________ and __________. What two factors can cause inaccurate/variation in readings?
inversely and exponentially; muscle mass and certain drugs
Hyponatremia on labs with isotonic serum osmolality can be caused by __________ or ___________. Hyponatremia on labs with hypertonic serum osmolality can be caused by ____________.
hyperproteinemia; hyperlipidemia/hypertriglyceridemia
Hyperglycemia
What is the best measurement for Vitamin D deficiency?
25(OH)D calcidiol aka 25-hydroxy Vitamin D
Iodinated contrast used in CT scans can cause ______________ and gadolinium contrast used in MRI can cause __________
nephrotoxicity; nephrogenic systemic fibrosis
What is the classic description of a varicocele on scrotal imaging? In what position will it be most apparent?
bag of worms :(
Standing or Valsalva
Microscopy to look for RBCs
Myoglobin and hemoglobin from hemolysis and rhabdomyolysis
FeNa has the most clinical value in patients who do not have ___________ _______ and not ______ ______
preexisting CKD; taking diuretics
What is plasma osmolality? Plasma tonicity?
Plasma osmolality- number of dissolved particles dissolved in plasma
Plasma tonicity- concentration of solutes that do not easily cross cell membranes
If PTH is low what other lab should be obtained?
magnesium
reduced kidney size and decreased cortical thickness
A doppler ultrasound of epididymitis would show _______ flow on the contralateral side and _________ flow on the symptomatic side
normal; increased
Vitamin C in urine can cause which tests to show up as false negatives?
Blood, glucose, leukocyte esterase
FeNa values and indications
<1% -
1-2% -
>2% -
<1% - can indicate pre renal disease
1-2% - may be seen in pre renal disease or ATN
>2% - ATN
What labs should be obtained for initial workup of hyponatremia? (5)
glucose, creatinine, potassium, serum osmolality, urine osmolality
What two abnormal values would indicate that hypercalcemia is 2/2 malignancy?
PTHrP (high) and PTH (low)
What are four findings on imaging that suggest renal cysts are malignant? What is the scoring system used to stratify the risk?
thickened walls, calcifications, mural (wall) nodules, enhancing components
Bosniak Criteria
Prostate carcinoma typically appears as a ________ lesion with ________ ________ on doppler
hypoechoic; increased vascularity
On microscopy, what condition is associated with each finding?
RBC casts-
WBC casts-
Renal tubular epithelial cell casts + granular casts-
Fatty casts and free oval fat bodies-
RBC casts- glomerulonephritis
WBC casts- interstitial inflammation, pyelonephritis
Renal tubular + granular- ATN
Fatty casts and free oval fat bodies- nephrotic syndrome and fatty emboli
GFR Stages for CKD Classification
G1-
G2-
G3a-
G3b-
G4-
G5-
G1- > 90
G2- 60-89
G3a- 45-59
G3b- 30-44
G4- 15-29
G5- <15
The major cation in the extracellular space:
Major anions (2) in the extracellular space:
Major cation in intracellular space:
Main intracellular anions:
sodium
chloride and bicarbonate
potassium
large macromolecular organic phosphates
If the cause of hypomagnesemia is unclear, what two tests could be ordered to help determine between GI and renal losses?
24 hour urinary magnesium excretion or fractional excretion of magnesium in urine (FEMg)
What study should you order if _______ is suspected?
Nephrolithiasis-
Renal mass-
Renal artery stenosis-
Nephrolithiasis- CT abdomen pelvis without contrast
Renal mass- CT abdomen pelvis WITH contrast
Renal artery stenosis- CT angiography
beta-HCG, alpha fetoprotein, LDH