GU/RENAL Flashcards
What is the anatomy of the GU/Renal system?
What are the indications for an x-ray KUB?
Useful in visualizing calcifications along the urogenital system
What is the technique for an x-ray KUB?
AP, Supine
Borders: lateral abdominal wall, just above the kidneys, inferior pubic rami
What is an example of a normal KUB?
What is this pathology?
KUB
Kidney stone in the left kidney or ureter
What is this pathology?
KUB
Calcifications called medullary nephrois calcinosom.
Not a very common disorder. Typically because there is too much calcium in the blood and its trying to get excreted.
Check and look for calcium levels in the patient
What is this pathology?
KUB
Urethral stone, abnormal calcification causing obstruction of the pubic symphysis, right in line with where the urethral should be exiting
What is pyelography?
Aka pyelogram, having to do with the renal pelvis, so where the kidney concentrates urine
IVP vs retrograde vs antegrade
Less commonly used now if CT available.
X-ray with contrast to enhance renal system
What are the indications of pyelography?
Use when concerned for an obstructive process. Evaluation of urinary tract for proposed pelvic surgery, after trauma to the urinary system, or when concerned about urinary outlet obstruction
What kinds of things can we find with pyelography?
Ureteric obstruction
Upper tract tumor
Papillary necrosis (damage to the renal papules)
Anatomical variants
Course of ureters
What is IV pyelography (IVP)?
Aka excretory urography
IV placed
Scout film obtained- no contrast image to make sure we don’t mask a stone or anything
Water soluble iodinated IV contrast given (important in patients with renal insufficiency, can it can worsen renal function)
Images taken at set intervals depending on the indication for the test
What is the pathology?
IVP
Contrast starts in the ureters and is narrowed
What is an example of a normal IV pyelography (IVP)?
Contrast is passing through the renal pelvis and into the ureters
Scalp film, kidneys aren’t super well visualized
Starting to be taken up by the kidneys
The slow movement of contrast into
The contrast is starting to make its way through to the bladder
What is the pathology?
IVP
Abruptly stops in the right ureter and is indicative of an obstruction
What are the indications for a retrograde pyelogram?
Nonvisualization of ureteral segment on IVP or CT urography
Better characterization of ureteral or pelvicalyceal abnormalities seen on IVP or CTU
Contrast is never going to cross into the bloodstream
What are the indications for an antegrade pyelogram?
Most often performed to evaluate nephrostomy tube position and function. We may do this if we are concerned that something isn’t draining properly or there is a blockage of the tube or theres a stricture. Don’t insert a nephrostomy tube just to do this!
What are some examples of normal retrograde pyelograms?
What are the techniques for a retrograde pyelogram?
The catheter is placed in the bladder and then in the ureter of interest. Water soluble iodinated contrast was given via catheter, but because it is not entering the blood vessels, we don’t have to worry too much about kidney issues. Multiple images obtained looking at areas of concern
What is an antegrade pyelogram?
Aka nephrostogram
Similar to retrograde pyelogram except contrast introduced via percutaneous nephrostomy tube (most likely inserted by an interventional radiologist)
What are the indications of cystography?
Evaluation of the bladder.
Examples: recurrent UTI, dysuria, dysfunctional vomiting, hydronephrosis/hydroureter, hematuria, trauma that is not acute, neurogenic dysfunction of bladder, congenital anomalies of GU tract, post-op eval of GU tract
What is a cystography?
Aka voiding cystography (VCUG)
What is the technique for cystography?
Empty bladder, urinary catheter insertion, contrast medium infused (only enough to fill the bladder, usually decided on patient demographics), once bladder full catheter removed, person voids and images taken using fluoroscopy (want to see real-time images) to assess bladder function and appropriate physiology
How can we diagnose vesicourethral reflux?
cystography
What are the contraindications for a cystography?
Suspected urethral or bladder injury
A pediatric patient comes in with fever and recurrent UTI, what diagnostic test should we refer them for?
cystography
What is this pathology?
Normal Cystography
Bladder looks full and we can still see the catheter in place
What is this pathology?
Normal Cystography
What is this pathology?
Normal CT Abd/Pelvis without contrast
This shows us what kidneys should look like. They should be similar in color to the liver
What is this pathology?
Cystography
Vesicuuretheral reflux. Contrast went backwards and while the catheter was still so they weren’t even voiding yet.
Causes: overgrowth of this area, trauma, muscular issue
What is this pathology?
CT Abd/Pelvis without contrast
Stone as it follows down the ureter from the right kidney to the bladder
What is this pathology?
CT Abd/Pelvis without contrast
Stone is stuck in the ureter
This would show hydroureter, which means an enlarged ureter from the proximal area and up
What is hydronephrosis?
a condition where urine builds up in the kidney, causing it to swell
What are the different types of CT?
CT Abd/Pelvis without contrast
- nephrolithiasis/ureterolithiasis (don’t want to use contrast, because it may mask or hide the stone)
CT Abd/ Pelvis with contrast
- Masses or lesions of GU tract
CT Urography
- Renal study
- Triple phase
- w/o contrast
- With the contrast in the nephrins
- With the contrast in the renal pelvis/ureters
CT Angiography
- Renal artery stenosis
What is this pathology?
Normal CT Abd/Pelvis with contrast
Kidney tends to light up a lot brighter because it is a vascular structure. Uniform in color
What is this pathology?
CT Abd/Pelvis with contrast
Left kidney has renal cell carcinoma sitting in the cortex and we can tell due to the change in color and shape.
What is this pathology?
Normal CT urography
What is this pathology?
Normal CT Angiography
Indicates the right renal artery as it comes off the abdominal aorta right in front
What is this pathology?
CT Angiography
The left renal artery is extremely constricted and may indicate stenosis. This can give us some good measurements and we can do a US with renal artery Doppler.
What is this pathology?
Had contrast. The kidneys are not symmetric. This is severe pyelonephritis. The left kidney tissue is inflamed and swollen and not take up the contrast in the way they normally would.
What is this pathology?
Overgrowth of fluid-filled cysts on the kidneys. People have hundreds and thousands. Very large kidneys in size. These kidneys are lumpy and bumpy but not the same in color. The cysts can range from very small to very large. There looks to be some cysts in the liver too. This may indicate autosomal dominant kidney disease (where patients who have these cysts, tend to get them in surrounding structures) or polycystic kidney disease
What is CT Urography?
It has largely replaced IVP
What are the indications for CT Urography?
Hematuria, Urothelial mass, obstructive uropathy, urothelial CA surveillance, stricture, congenital collecting system abnormality
What is the technique for CT Urography?
Triple phase CT
3 parts to it: non contrasted part contrast is just in the cortex of the kidneys, and as it gets excreted into the urine, into the calyces and into the pelvis
What is this pathology?
Abnormal Rengogram
On the far left, it starts with the patient before the tracer at 0 secs and after they receive the tracer, we see the tracer taken up and seems to get darker and darker and as times goes on and through the bloodstream. We start to see the left kidney seems to be getting darker and darker, whereas the right kidney is not really changing a whole lot. we start to see the tracer starting to get excreted down to the bottom of the bladder. This study is letting us know that we have pretty good function in the left kidney. The report proceeds a percentage of function and looks at the total of the two kidneys, are they working equally, etc.
What is this pathology?
Normal Renal US
The kidney looks like it is on its side, not how it is positioned in the body. The report will usually give kidney sizes, can see the ureters, and hydronephrosis, if there are stones. Can also add on a patient bladder US with a post-void residual, to make sure the patient is voiding appropriately.
What are the indications for an MRI?
Evaluation of masses. Patients who cannot have iodinated contrast due to allergy can get an MRI.
What is a big concern and side note for using MRI on certain patients?
Patients with renal impairment SHOULD NOT receive IV gadolinium contrast for MRI given the concern for nephrogenic systemic fibrosis, is a rare side effect that causes very painful fibrosis of the skin and underlying skin structures.
What are the indications for nuclear medicine?
Assess perfusion, function, and structure of the kidneys, presence of obstruction, presence of renovascular hypertension, and monitor renal function in patients with known renal disease or transplant.
What is the technique for nuclear medicine?
Radionucleotide (no iodinated or gadolinium contrast), is perfectly fine for patients with chronic kidney disease
+/- lasix administration- diuretic and causes patient to void more quickly
What is an US?
Safe, no contrast. Study of choice for general GU evaluation (except for something like a kidney stone)
What are the indications for US?
Flank pain, hematuria, UTI- concern for pyelonephritis, AKI/CKD, evaluation of congenital abnormalities, detection/follow-up of cysts or masses, post-op eval, with doppler can eval renal artery stenosis, make sure someone is poor with both kidneys, horseshoe kidney
What is cystoscopy?
Endoscopic evaluation of the urethra, bladder, and ureters
What are the indications for cystoscopy?
Suspected pathology of GU tract, hematuria, recurrent UTI, and a variety of GU complaints, can be used to obtain biopsy and can be diagnostic and therapeutic
How can cystoscopy be diagnostic?
Direct visualization
Identify stone location
Identify the source of hematuria
How can cystoscopy be therapeutic?
Stone retrieval (UPJ or urethra pelvic junction)
Removal or treatment of small bladder tumors
Dilatation of urethra or ureters
Placement of stents (lithotripsy to break up the stone)
What are some of the normal findings on cystoscopy?
Evaluation of urethra: males- prostate enlargement and make sure it isn’t pressuring against the urethra
Evaluation of bladder mucosa: lesions/masses, friability- irritability, how much does it bleed or sloth off, abnormal vascular structures
Two ureteral orifices: ureteral jets-as urine passes into the bladder from the ureter, size of the opening, strictures
Typically done in the urologist office or the OR. The patient is typically awake or under light anesthesia, but they have to hold their legs up.
What is urodynamics?
A series of tests to evaluate bladder function
What are the indications of urodynamics?
Frequent UTIs
Incontinence
Overactive Bladder
Urinary retention
What are the findings of urodynamics?
Degree of retention
Sensation of bladder fullness
Bladder compliance and pressures
Urine stream pressure and flow
What are the contraindications of urodynamics?
Active UTI, can affect the result and has a risk of introducing or causing an infection
What are the complications of urodynamics?
Active UTI, can affect the result and has a risk of introducing or causing an infection
What are the different types of urodynamics?
Post-void residual
Uroflowmetry
Cystometric test
Leak point pressure management
Pressure flow study
Electromyography
Video urodynamic test
What is Post-void residual?
Pre and post-void management should be less than 50 ml
Measurement of how much urine is in the bladder, before and after micturition
What is Uroflowmetry?
How much urine is in the bladder and how fast it comes out
What is a Cystometric test?
How much bladder can hold? How much pressure builds up? How full before feel urge?
What is Leak point pressure management?
The measurement taken is leaking noted while filling the bladder
What is a Pressure flow study?
How much pressure is needed to urinate? Flow rate at that pressure
What is Electromyography?
Aka EMG, Special sensors to measure the electrical activity of muscles and nerves in and around the bladder and sphincters. Helpful in distinguishing between neurological causes vs bladder and muscle dysfunction
What is a Video urodynamic test?
X-ray or US to take pictures/video as the bladder fills and empties
What are the presenting complaints for bladder cancer?
Often painless Gross hematuria, irritative sx (ie frequency or urgency), rarely pain unless obstructive
What are the diagnostic criteria for bladder cancer?
Diagnostic via cystoscopy w/ biopsy +/- cytology
No dx serum marker available- some markers such as CEA can be elevated but are not specific enough to be considered diagnostic
What is the dx test for prostate cancer?
Prostate-specific antigen (PSA) (total, bound or unbound)
What are the indications for prostate cancer?
Screening for early detection of prostate cancer
Monitoring response to therapy and for recurrence
What are the notes for prostate cancer?
Elevation is associated with prostate cancer but not specific
< 4.0 cancer is less likely
> 10.0 cancer is likely
4-10 can be cancer but could also represent: BPH or prostatitis
Collect PSA antigen before doing what?
A digital rectal exam
What is a Free PSA and Free/Total PSA Ratio in relation to cancer?
Free PSA is decreased in cancer
What does the USPSTF recommend as screenings for prostate cancer?
Age 55- 69 screen those who wish to undergo screening
Shared decision after discussion of risk/benefit
Benefit-small potential benefit of reducing the chance of death from prostate cancer
Risk-false positive. Further required evaluation. Possible need for biopsy
Age > 70 years old- do not screen
Currently under review
What are the newer tests for prostate cancer?
Free PSA and Free/Total PSA Ratio
Prostate Health Index (PHI)
If PSA or PHI are elevated, need additional imaging and biopsy.
What is a Prostate Health Index (PHI)?
Uses total PSA (will be high), free PSA (low number, unbound PSA), and other manufacturer-specific tests to calculate PHI, and higher PHI is associated with increased risk of cancer
What are the indications for a prostate and rectal US?
Early diagnosis of prostate cancer in patients w/ elevated PSA
Evaluate prostate cancer
Guide biopsy
Stage and monitor rectal cancer
Detect perirectal disease
What is the technique for a prostate and rectal US?
Local in office (urology) vs sedation in OR
10-12 specimens obtained to be accurate
What are the indications for a ProstaScint Scan?
Staging of prostate cancer
What is the technique for a ProstaScint Scan?
Nuclear medicine study
Uses radioactive tracers that is taken up by prostate cancer cells.
What are the notes for a ProstaScint Scan?
Not a screening test. It is just looking for the extent of the metastatic disease.
What are the most common types of renal cancers?
Relatively slow-growing
Renal cell carcinoma is the most common renal cancer- typically found incidentally on other imaging. Most common presenting symptom is hematuria and then during the workup, the patient is found to have a mass on the kidney
Wilms Tumor and is more common in pediatric patients- mass on kidney
What are the risk factors for renal cancers?
Smoking
Are there any screening tests for renal cancers?
No there are no screening tests for this
What are the indications for labs for semen analysis?
Evaluate the quality of sperm for infertility eval
Document the adequacy of vasectomy
What are the notes for labs for testosterone?
Most circulating testosterone in men is made by Leydig cells in the testicles.
Level varies by stage maturing (Tanner stage)
98% of testosterone in circulation is bound to proteins and inactive
- Most tests measure total but can specifically order free testosterone level
What are the indications for labs for testosterone?
Evaluate ambiguous sex characteristics
Precocious puberty
Female virilizing syndrome (development of male secondary sex characteristics- increased body hair, deeper voice, and acne), may indicate issues like PCOS
Male infertility- most often use
What are the notes for labs for semen analysis?
Infertility in couples is sometimes due to semen inadequacy quality or quantity
Spermatogenesis depends on the function of testicles
- dysfunction = reduced sperm count and/or increased abnormal forms
What are some factors that affect the primary dysfunction of semen?
Primary dysfunction, genetic causes, infection, radiation
Something wrong with the testicles themselves.
What are some factors that affect the secondary dysfunction of semen?
Secondary dysfunction- pituitary issue, systemic diseases
Something that is affecting the hormone cycles
What are the indications for antispermatazoal antibody?
Infertility screening to detect antibodies against their own sperm. The presence of antibodies can result in diminished fertility
What is an example of the male GU US?
This is a Doppler study where blue and red indicate blood flow on the left. On the right, the Doppler study does not have any blue or red highlights indicating testicular torsion.
What is the test of choice for male GU imaging?
US is generally the imaging modality of choice
Evaluate masses- testicular cancer and hydrocele
Evaluate blood flow for testicular torsion (doppler studies)
What are the functions of the kidney?
Waste removal
Water management
Electrolyte balance
PH regulation for acids and bases
Regulation of blood pressure through the RAAS system
Blood production for EPO
Bone health for activation of vitamin D
How does urine get filtered?
Through the nephrons in the cortex and the medulla and through the glomerulus.
What is a urinalysis?
Part of routine diagnostic and screening evaluation. Usually part of first line screening and evaluation
What are the indications for a urinalysis?
Signs and symptoms: flank pain, back pain, dysuria, frequency, hematuria, dyspareunia
Monitoring of CKD and is part of the AKI evaluation
A urinalysis will get info on What?
Urinary tract disease diseases: infection, GN, hydration status
Extra renal disease diseases: diabetes, liver disease
How is urinalysis collected?
Random versus First of the morning
Midstream clean catch versus catheterized: If not obtained either of these ways can risk contamination
How is the testing for a urinalysis completed?
Should be completed in 30 minutes to an hour after specimen is obtained. After that, it should be refrigerated.
At room temperature: Cells and cast begin to deteriorate, bacteria multiply, bilirubin, urobilinogen, ketones, and glucose will decrease, pH may increase, amorphous phosphates and urates may precipitate
What is the ideal way we would like a urine collection?
First of the morning (more concentrated) and a midstream clean catch (clean outside first to avoid bacteria from skin), because it is most accurate
What should be observed on a urinalysis?
Appearance, color, outer
A dipstick urinalysis assesses what?
pH, specific gravity, urobilinogen, bilirubin, blood, leukocyte esterase, nitrates, ketones, Glucose, and protein
A microscopic analysis of a urinalysis will show what?
Cells, crystals, casts, and microorganisms
What should the appearance of urine look like in a UA?
Urine should be clear
If urine looks cloudy on a UA what could that indicate?
white blood cells present and that may indicate some bacteria
If urine has bubbles present or it looks foamy on UA what could that indicate?
proteinuria. (seen more with LARGE amounts of protein)
What should the color Of urine look like on a UA?
A urine should be a pill yellow straw colored or dark yellow
A dark yellow urine color on UA may indicate what?
Dehydration
A Amber urine color on UA may indicate what?
bilirubin metabolism issue or the presence of myoglobin
A red urine color on UA may indicate what?
Blood
A Green, blue, black urine color on UA may indicate what?
Green (psudeomonas), blue (methylene blue from surgery), black MAYBE due to some sort of food, drugs, or genetic errors in metabolism
A strong, sweet odor of urine may indicate what?
DKA
A foul odor of urine may indicate what?
UTI
A stool odor of urine may indicate what?
Enterovesical fistula
What is the only exception to the rules of color on a UA?
Phenazopyridine (Pyridium, aka AZO) because it is a urinary tract analgesic that turns urine orange to red
What does a UA dipstick look like?
What is the normal ph of urine?
5-8
What would alkaline urine indicate?
Alkalemia, some UTIs (ex: Proteus), Certain drugs
What would acidic urine indicate?
Acidemia, starvation, high meat – protein diet. Associated with crystal formation: uric acid, calcium oxalate, xanthine, cystine
What is specific gravity?
Ratio of weight of a given fluid (urine) To an equal volume of distilled water. It is a measurement of the kidneys ability to appropriately concentrate urine
What is the normal specific gravity?
“Normal”= 1.000-1.030
1.000 is equivalent to pure water
Why is a normal specific gravity relative?
If your patient is dehydrated in their urine is still very dilute, it means the kidneys aren’t concentrating things the way that they should. So even though it may fall within the normal range, if it’s on the lower end, in a patient who’s dehydrated we were to expect for it to be on the higher end
What are the measurements of specific gravity?
Dilute (1.005) : Diuretics, diabetes insipidus, very well hydrated
Concentrated (>1.020): Dehydration, increased solutes
Isosthenuria (1.010): Urine osmolality equals plasma osmolality. Can be indicative of underlying renal disease if kidneys aren’t able to adequately dilute or concentrate urine
What is normal urobilinogen?
Formed by bacterial conversion of conjugated bilirubin in the small intestine
Urobilinogen may be increased in patients with?
Increased turnover of heme (Hemolytic anemia), CHF with liver congestion, cirrhosis, viral hepatitis, drug induced hepatotoxicity
Urobilinogen may also indicate what type of liver disorders?
What would normal Bilirubin show?
Always conjugated Bilirubin
Normal: negative
What would abnormal bilirubin look like and what patient populations would it be increased in?
Abnormal would be positive.
It would be increased in patients with intrahepatic cholestasis and Post-hepatic obstruction
What are some causes of blood in the urine?
Trauma, stones, menstruation, cystitis, tumor, glomerulonephritis
If blood in the urine is positive, what happens?
Check RBC’s on microscopic exam
Hematuria= + blood, + intact RBC
Hemoglobinuria= + blood, - RBCs and may be due to lysed RBCs or myoglobinuria (rhabdomyolysis)
What is leukocyte esterase?
Estimate of pyuria (WBCs in urine)
Normal: Negative to trace
What are the causes of an abnormal Leukocyte esterase?
UTI, sterile pyuria, acute interstitial nephritis, inflammatory processes in the GU tratc, that may not necessarily have infection
Why is nitrite important in a UA?
Indirect indicator of UTI
Specific but not highly sensitive
Organisms (mostly gram-negative bacteria) convert nitrates to nitrite
Some staph species, E. coli, Klebsiella (knowing which, may help guide abx choice)
What are the normals and abnormals of nitrites on UA?
Normal is negative
Abnormal is positive
Causes: UTI w/ positive leukocyte esteraste
Why is glucose important in a UA?
Filtered in the glomerulus but nearly completely reabsorbed in the proximal tubule
Serum glucose > about 180, will spill over into the urine and that is when we wil start to get positives on the dipstick
What are the normals and abnormals of glucose on UA?
Normal is negative
Abnormal is positive
What are some causes of glucose on UA?
Diabetes mellitus, renal tubular disease, some medications: IV dextrose administration, SGLT2i (treat diabetes, things like jiardiance, farciga)
What are the normals and abnormals of ketones on UA?
Normal: negative
Abnormal is positive and the derangement of carbohydrate metabolism. In association with + glucose is suggestive of uncontrolled DM (DKA)
What are some of the causes of abnormal ketone levels?
Pregnancy, carbohydrate free diet (Keto), starvation, febrile illness in children
Why is protein important on UA?
Primarily measuring albumin
What are the normals and abnormals of protein on UA?
Normal: Negative
Abnormal: Trace amounts
What are the causes of protein abnormals?
Intrinsic renal disease like glomerulonephritis, nephrotic syndrome, DM nephropathy, preeclampsia in pregnant women, and multiple myeloma
What would a microscopic evaluation contain?
Sediment obtained by centrifugation and analysis by microscope
A normal urine may contain what on microscopic eval?
A few WBCs, a few RBCs, a few bacteria, a few epithelial cells, a few hyaline casts
Outisde of this, we shouldn’t really see much on the microscope slide.
When can WBC be increased on microscopic eval?
Can also be increased in inflammatory conditions of the kidneys. Glomerulonephritis and Interstitial nephritis. Increased is called pyuria: when seen in clumps with bacteria are indicative of infection
What are the normal WBC on microscopic eval?
Normal = 0-2
What are the normal RBC on microscopic eval?
Normal 0-2
When can RBC be increased on microscopic eval?
Damage to glomerular membrane-appear dysmorphic
Post-renal injury/trauma- appear normal in shape
Can be seen following strenuous exercise but disappear with rest
How can we tell the difference between WBC and RBC on the microscope slide?
The RBCs look kind of like a little oil droplet and may have a little rainbow tint to them.
The WBCs look more fuzzy
What should normal epithelial cells look like on microscopic eval?
0-2/hpf
What should squamous epithelial cells look like on microscopic eval?
Originate from external genitalia or lower urinary tract. In large numbers typically means not a clean catch urine or contamination from the skin. Recollect and get a clean catch specimen (or from a cath) or talk to the patients about their sx
What should transitional epithelial cells look like on microscopic eval?
Originate from the bladder, uterus, or renal pelvis. A few may be normal but typically elevated in trauma or cancer.
What should renal tubular epithelial cells look like on microscopic eval?
Originate in nephron tubules. Indicates acute tubular necrosis, acute interstitial nephritiis, or proliferatie glomerulonephritis.
What do WBC, Squamous epithelial cells, transitional epithelia cells, bacteria, and renal tubualr epithelial cells look like on microscopic eval?
What is a cast?
Cylindrical masss of glycoproteins that form in the tubules.
What are the types of casts?
Hyaline
Waxy
Cellular
- WBC
- RBC
- Granular
What is a hyaline cast?
Nonspecific and may not be pathologic
Prerenal azotemia and strenuous exercise (dehydrated, not replenishing fluids fast enough)
May be normal
What is a waxy cast?
Nonspecific but pathologc
Seen in advanced or chronic kidney disease.
What is a cellular cast?
WBC casts: seen in pyeloneprhitis or interstitial nephritis or glomerulunephritis
RBC casts: classicially seen with acute glomeruluonephritis
Can also be seen with trauma, pyelo, renal tumor, renal infarct, or sickle cell disease
Granular casts: from cellular debris trapped in the glycoprotien
“Muddy brown”-ATN
PATHOLOGIC
What does a hyaline cast and waxy cast look like on microscopic eval?
The hyaline cast is a little tube that forms. The waxy casts, which are like the hyaline casts, but have been hanging around for a lot longer. The waxy casts have roughing edges, but are still clear, because its just native proteins. No extra cells are stuck in it.
What is this pathology?
RBC cast. Lots of little RBCs in that little tubular structure, stuck in the protein matrix
What is this pathology?
Granular cast
What is this pathology?
WBC cast
Describe crystals on microscopic eval
Presence depends on urine pH, deree of saturation of urine by substance, and presence of other substances that promote crystallization.
What are the characteristics of formation and diagnostic utility of uric acid?
Formation promoted by uric acid. Seen in tumor lysis syndrome and also seen in gout.
What are the characteristics of formation and diagnostic utility of calcium phosphate?
Formation promoted by ALKALINE urine and not suggesitve of any specific systemic disease.
What are the characteristics of formation and diagnostic utility of magnesium ammonium phosphate?
Aka struvite or “triple phosphate”. Formation promoted by ALKALINE urine and seen in UTIs by urease producing organisms
What are the characteristics of formation and diagnostic utility of calcium oxalate dihyrdrate?
Formation is largely independent of urine pH. Not suggestive of any specific systemic disease, but is COMMONLY SEEN IN KIDENY STONES
What are the characteristics of formation and diagnostic utility of calcium oxalate monohyrdrate?
Formation is largely independent of urine pH. Seen in ethylene glycol ingestion.
What are the characteristics of formation and diagnostic utility of cystitine?
Formation promoted by acidic urine and is diagnostic of cystinuria
What are the most common crystals seen in nephrotic syndrome?
Cholesterol
What common organisms will we see on microscopic eval?
Bacteria, yeast, trichomonas vaginalis
What is this pathology?
Strands of bacteria
What is this pathology?
Yeast
“Spaghetti and meatballs”
Hyphae
Budding yeasts look like little round circles.
What is this pathology?
Trichomonas
Little football shaped guys that have a flagella or tail
May also be referred to as “swarming trichomonas”
What are the expected UA outcomes for hemolytic anemia?
Increased urobilinogen, no bilirubin
What are the expected UA outcomes for hepatocellular inflammation (hepatitis)?
Positive bilirubin, increased urobilinogen
What are the expected UA outcomes for biliary obstruction?
Positive bilirubin, low urobilinogen
What are the expected UA outcomes for rhabdomyolysis?
Positive blood, no RBC’s
What are the expected UA outcomes for acidic urine?
Calcium oxalate, amorphous, uric acid crystals
What are the expected UA outcomes for nephortic syndrome ?
Positive protein
What are the expected UA outcomes for alkaline urine?
Triple phosphate, ammonium biurate crystals
What are the expected UA outcomes for diabetes mellitus?
Positive glucose, negative ketones
What are the expected UA outcomes for DKA?
Positive glucose, Positive Ketones
What are the expected UA outcomes for starvation/low glucose diet?
Negative glucose, positive ketones
What are the expected UA outcomes for developing kidney disease?
Positive protein, later stages – specific gravity is about 1.01 repeatedly
What are the expected UA outcomes for ATN?
Positive muddy brown cast, plus or minus renal tubule cells
What are the expected UA outcomes for acute interstitial nephritis?
Positive WBCs, Positive WBC cast, positive leukcyte esterase, Negative nitrites, no bacteria
What are the expected UA outcomes for acute cystitis?
Positive WBC’s, positive leukocyte esterase, +/- nitrites, positive bacteria, +/- triple phosphate crystals
What are the expected UA outcomes for glomeruloneprhitis?
Positive blood, positive RBC’s, positive dysmorphic RBC’s
What are the expected UA outcomes for pyelonephritis?
Positive WBC, positive WBC clumps, positive bacteria, positive leukocyte esterase, +/- Nitrites, =/- WBC casts
What are the expected UA outcomes for cancer?
Positive blood, positive RBC, +/- cells
What are the expected UA outcomes for nephrolithiasis, ureterolithiasis, and cystolithiasis?
Positive blood, positive RBC, no dysmorphic cells, +/- Crystals
What is the indication for a urine culture?
Recurrent infections and treatment failure
Complicated UTI
Pregnancy
What are the common UTI micro-organisms?
2+ Organisms reported typically contamination
Either gram-positive or gram-negative
What are the common UTI gram positive organisms?
Staph species
Enterococcus species (hygiene issues from GI tract)
What are the common gram-negative organisms?
Lactose fermenting
- E. coli (most common)
- Enterobacter (most common)
- Klebsiella (more common in immunocompromised)
Non-lactose fermenting
- Proteus
- Pseudomonas
How long does it take to receive the report for a urine culture?
It can take up to 48 hours to get a urien culture back, so a lot of times we will need to treat the patient empirically and change abx as needed
On a CFU report, what does I, R, and S stand for?
I: Intermediate
R: resistant
S: Sensitive
What urine culture colony counts indicate infection?
> 100,000 CFU/mL = infection
10,000-100,000 CFU/mL = Possible infection
< 10,000 CFU/mL = No infection
CFU= colony forming units
What are the indications for a microalbumin?
Monitor for developing disease-typically diabetic nephropathy: Recommend that patient’s older than 12 with a diagnosis of diabetes mellitus receive an annual microalbumin testing
Monitor for response to treatment
What are the severity levels of Albuminuria?
Normal= < 3 mg/dL
Moderately increased albuminuria (Old term=Microalbuminuria) = 3-30 mg/dL
Severely increased albuminuria = > 30 mg/dL
Urine dipstick: +1= 30 mg/dL
What is microalbumin?
The presence of albumin and urine higher than normal, but under the threshold of detection on routine urine test
What is the technique for a microalbumin?
Random urine specimen
What are the indications for a urine albumin/ Creatinine ratio (ACR)?
To quantify the amount of albuminuria present
Simply measuring albumin concentration and urine can be misleading (False positive or a false negative) as it is influenced by the volume of urine
What is the technique for an ACR?
random urine specimen
What are the levels for a normal and abnormal ACR?
Normal < 30 mg/g
Abnormal: 30-300 mg/g is likely microalbuminuria
> 300 mg/g is likely significant albuminuria
What are the indications for a urine protein/ Creatinine ratio (PCR)?
To quantify the amount of protein present
This is just a screening tool used to make adjustments of treatment
What is the technique for a PCR?
Random urine specimen
What are the normal values for a PCR?
< 200 mg/day
What are the abnormal values for a PCR?
200-500 mg/day is mild
500-1000 mg/day is moderate
> 1000 mg/day is severe
> 3000 mg/day is nephrotic range
What is an important note about a urine PCR and urine ACR?
Urine PCR and urine ACR should be similar. If there is a significantly larger urine PCR than this is concerning for abnormal proteins in the blood. This could be indicative of diseases like multiple myeloma
What is the indication to do a 24 hour urine assessment?
Accurate assessment of proteinuria
Protein analysis (UPEP)
Accurate assessment of renal function (for CrCl)
Needs serum specimen collected at the time jug is returned
What is the technique to do a 24 hour urine assessment?
First urine specimen of the day is flushed and does not have to be a clean catch. Every drop of urine after that for the next 24 hours is collected. Specimen must remain refrigerated. Gives us a more accurate clearance or indication of numbers to assess what is going on.
What are some renal function test?
BUN, creatinine, eGFR, Creatinine clearance (CrCl), BUN/Creatinine ratio
What is the normal range for BUN?
5-20 mg/dL
What is BUN?
Comes from protein waste products after metabolism in the liver
An increased BUN could be caused by what?
Also called azotemia
AKI (will be significantly elevated) or CKD (should definitely be elevated)
G.I. bleed
Steroid use
High protein diet or IV nutrition
A decreased BUN could be caused by what?
Severe liver disease
What is creatinine?
Product of breakdown of creatinine phosphate and is secreted by the kidneys
Elevated when there are issues with the kidneys
What is the normal range of creatinine?
0.5-1.3 mg/dL
Depends on the muscle mass of the patient
An increase in both BUN and creatinine is indicative of what?
Renal pathology
What are the indications for a creatinine clearance assessment (CrCl)?
To assess renal function
What is the technique for a creatinine clearance assessment (CrCl)?
Most accurate is 24 hour urine collection with serum creatinine
What are the notes for a creatinine clearance assessment (CrCl)?
Creatinine is found in skeletal muscle
Creatinine is a form of creatine that is targeted for removal by kidneys
Creatinine is produced at a relatively constant rate
How can GFR be interpreted?
Creatinine levels rise, GFR levels decrease
Relationship of Serum creatinine to GFR is logarithmic
For every 50% reduction in GFR, serum creatinine doubles
At serum creatinine < 2 mg/dL, Small changes in creatinine indicate decreases in GFR
At serum creatinine, > 4 mg/dL, big changes in creatinine indicate much smaller decreases in GFR
This is not a good test measure. But gives a good indication in addition to the creatinine clearance. But the GFR will be provided on a lot of BMP’s and CMP’s.They have an estimate usually based off of the reactant level
What is GFR?
Some of the filtration of all functioning nephrons
Unable to measure a true GFR: closest equivalent is a 24 hour urine creatinine clearance
Currently accepted calculation is eGFR which uses creatinine, sex, and age
Usrful only in stable renal function
Why are the stages of CTD important?
We use GFR to place patients in categories of kidney disease.
GFR may change daily, but in order to place people in stages of kidney disease, we have to categorize themn based on STABLE ONGOING continuous eGFR rates, but we want the BUN/creatinine to stay the same.
People with kidney disease must be what before we put them in a class?
Stable kidney function
Describe patient at stage one kidney disease
GFR is normal, but they have some sort of injury, insult, trauma, defect in the kidney that they have isn’t versatile but has normal kidney function. GFR is greater than 90
Describe patient at stage two kidney disease
GFR is between 60 to 90
Describe patient at stage three kidney disease
GFR is between 30 to 60 and they decided a few years ago to split stage three into two categories with stage a and stage B
Describe patient at stage four kidney disease
This is when we start talking to patients about stage renal disease because they have a GFR of less than 30 But they’re not on dialysis yet, But they could potentially be a candidate
Describe patient at stage five kidney disease
When GFR is less than 15 and they are on dialysis. But once the kidneys have failed and they need to start dialysis we turn them into in stage renal disease
What is acute kidney injury?
increase in serum creatinine by greater than or equal to 0.3 mg/dL ( Greater than or equal to 26.5 micromol/L) Within 48 hours; or
Increase in the creatinine to greater than or equal to 1.5 times baseline, which is known or presumed to have occurred within the prior seven days; or
Urine volume less than 0.5 mL/kg/h for 6 hours (also know as oliguria)
What is a subacute kidney injury?
Decline in renal function in less than three months
What is chronic kidney disease?
CKD
Slow decline of renal function overtime
GFR < 90 ml/min or albuminuria/abnormal imaging that has been present > 3 months
What are the pre-renal causes of subacute or acute kidney injury?
Increased BUN and creatinine secondary to a decrease in renal perfusion. Low blood flow to the kidneys
Hemorrhage; hypertension from shock, dehydration due to prolonged diarrhea or decreased intake, low perfusion states like congestive heart failure, portal hypertension, renal arteries stenosis or embolism, and aortic dissection
What are the different causes of subacute or acute kidney injury?
Pre-renal, intra-renal, post-renal
What are the post-renal causes of subacute or acute kidney injury?
Acute renal insufficiency resulting from a structural or functional impede of urine flow. Outflow obstruction like calculi, tumors, enlarged prostate. Almost always an obstructive process, anywhere from the ureters down
What are the intrinsic causes of subacute or acute kidney injury?
Acute renal insufficiency resulting from disorders affecting the renal vascular, glomerulus, tubules, or interstitium. Abnormal glomerular filtration, tubular action, or renal blood vessels
Vasculature: Vasculitis, HUS, Scleroderma, NSAIDs
Glomerulus/ capsule: Call Mariola nephritis, nephrotic syndrome,CPK from rhadomyolysis, lupus
Tubular: Acute tubular necrosis which is often ischemia induced from low perfusion, contrast dye, antibiotics, tumor lysis syndrome, multiple myeloma
Interstitial: acute interstitial nephritis most likely due to an allergic reaction to a drug, Pyelonephritis
What are the possible urinalysis findings for acute kidney injury test?
Prerenal cars: bland sediment, few highline cast
Intrarenal cause:
Glomerular: Dysmorphic RBC’s, RBC cast, Proteinuria
Tubular necrosis: Granular cast (muddy brown), Renal tubular epithelial cells
Interstitial: WBC’s, WBC cast, no bacteria, some proteinuria
Post-renal cause: Whole RBC’s
How can the BUN and creatinine ratio help us determine the causes of acute kidney injury?
Can only use this test when both are elevated
Normal: 10:1 to 20:1
Abnormal:
> 20:1
Prerenal, acute post renal, intrarenal-GN
<15:1
Intrarenal-ATN, AIN, chronic post renal
When can we use the BUN and creatinine ratio diagnostically for AKI?
Can only use when both BUN and creatinine are elevated
What is the fractional excretion of sodium (FENa)?
= [(UNa x PCr)/(PNa x UCr)]*100
Value < 1.0 = cause of AKI likely from underperfusion
Kidneys respond to decreased perfusion by conserving Na
Value > 2.0 = cause of AKI likely from tubular damage
Inability to conserve Na
What are the limitations of the fractional excretion of sodium (FENa)?
Multiple causes of low FENa other than prerenal AKI
Cannot use in patients w/ salt wasting nephropathy or diuretic use
Small sample size of studies supporting its use
What are the specific test related to AKI?
Complements, ANCAs, Anti-GBM antibodies, SPEP, UPEP, Streptococcal testing, renal biopsy, heavy metals
What are the notes for compliments?
Serum complement is a group made of 31 proteins that work in a cascade like series to synthesize proteins that facilitate immunologic and inflammatory responses. Most commonly measured are C3 and C4. Low in complement mediated nephritis and sometimes check CH50
What are the indications for compliments?
Done as part of AKI evaluation when etiology incertain.
Screens for and diagnoses hereditary deficiencies of complement peptides and monitors activity of autoimmune diseases like Lupus and severly type of nephritis
What is anti-neutrophilic cytoplasmic auto antibodies (ANCAs)?
DEFINITELY WANT THESE IF THERE IS BLOOD IN THE URINE
Associated w/ vasculitides which can lead to AKI
pANCA and cANCA
What are anti-glomerular basement membrane antibodies (Anti-GBM Ab)?
Indicative of autoimmune induced nephritis (Good pasture Syndrome)
Autoimmune disorder against the glomerular basement membrane
Pathognomonic triad: presence of circulating antibodies, glomeruloneprhitis (hematuria), and pulmonary hemorrhage (hemoptysis), maybe some proteinuria
What are the indications for serum protein electrophoresis (SPEP)?
Evaluation of kidney disease when etiology is unknown or uncertain
Evaluation with suspect of possible multiple myeloma (M-spike)
What is the technique for SPEP?
Blood draw
What are the indications for urine protein electrophoresis (UPEP)?
Evaluation of kidney disease when etiology is unknown or uncertain
Evaluation with suspect of possible multiple myeloma (M-spike)
What is the technique for UPEP?
24 hour urine collection
What is Streptococcal Testing for AKI?
Includes antistreptolysin O (ASO), Anti-DNase (ADB), Streptococcus Group B antigen (Streptozyme)
What are the indications for strep testing?
Identify previous infection by group a streptococcal (GAS) bacteria
What is the explanation of strep testing?
Tests for antibodies directed against GAS extracellular enzymes
When do we do a kidney biopsy?
This is the last resort
What are the indications of a kidney biopsy?
Diagnose cause of renal disease
Evaluate possible malignancy if patient not a surgical candidate
Evaluate transplant rejection
What is the technique for a kidney biopsy?
Patient has to be able to lay flat on their belly. Every now and then they may have them on an incline table laying down. Typically they lay flat on their belly and then using either CT or ultrasound they’ll find the area where they want to take the biopsy. They were usually take a few different areas of biopsy to make sure we’re getting a full picture and will note glmoeruli, papillary necrosis, any scarring and additional abnormalities
Who performs a kidney biopsy?
Interventional radiology were performed the biopsy in the facility but the specimen will be sent off to a different facility usually in a bigger city like Charlotte to be interpreted by a renal pathologist.
What are our heavy metals?
Aluminum and other heavy metals
Deposit and many body tissues and can lead to kidney injury
What are the indications for heavy metal assessment?
Assess heavy-metal levels and patient with renal failure
This is really done anymore
Dialysis is not highly effective at eliminating aluminum
If a PaO2 is low, but A-a gradient is normal, what happens?
Hypoventilation (ex: opioid overdose)
High altitude
If PaO2 is low and A-a gradient is elevated, what happens?
Pulmonary causes of hypoxemia like pneumonia, PE, pulmonary edema, or ARDS
What are our heavy metals?
Aluminum and other heavy metals
Deposit and many body tissues and can lead to kidney injury
What are the indications for heavy metal assessment?
Assess heavy-metal levels and patient with renal failure
This is really done anymore
Dialysis is not highly effective at eliminating aluminum
What are the labs to assess the waste removal function of the kidney and what would be the results in CKD?
Labs: BUN and Creatinine
Results in CKD: Elevated for both
What are the labs to assess electrolyte balance function of the kidney and what would be the results in CKD?
Labs: Results in CKD:
Na: Low to Normal
K: High
What are the labs to assess pH regulation function of the kidney and what would be the results in CKD?
Labs: Results in CKD:
CO2 on BMP/CMP is low
What are the labs to assess the blood production function of the kidney and what would be the results in CKD?
Labs: Results in CKD:
Hgb is low (goal of 10)
What are the labs to assess the bone health function of the kidney and what would be the results in CKD?
Labs: Results in CKD:
Calcium is low
Vit D is low
PTH is high
Phosphorus is high
How often are tests and screenings done for CKD?
Hgb: CKD Stage III at least yearly, CKD stage IV/V test at least every 6 months.
ESRD tested monthly at outpatient clinic. CKD patients often get secondary hyperthyroidism
What is serum osmolality?
Measure of dissolved particles in a fluid
What is the normal range for serum osmolality?
280-295 mOsm/kg
What are the causes of abnormal serum osmolality?
High-Dehydration, hypernatremia, hyperglycemia, kidney disease, diabetes insipidus, certain medications
Low- Excessive water intake, hyponatremia, SIADH, Burns, certain meds
What is the normal range for urine osmolality?
Normal range can vary widely
300-900 mOsm/kg
What are the causes for abnormal values of urine osmolality?
Clinical scenario must be taken into account
Patient comes in that hasn’t eaten in four days and has had nausea vomiting and diarrhea for that entire time
Normal for them should be on the higher end and the abnormal for them would be on the low to mid normal
If urine osmolality remains close to serum osmolality despite the clinical scenario that could have significant indications of CKD
What are the indications for urine sodium?
Assessment of etiology of AKI needed for FENa
Evaluation of etiology of hyponatremia
What is the technique for urine sodium?
Can get spot random for 24 hour urine
What is the normal range for urine sodium?
20-220 mEq/L
What are the abnoramls for urine sodium?
Low (<20 mEq/L)- Dehydration, kidney disease, or adrenal insufficiency
High (>220 mEq/L)- Diuretic use, salt losing nephropathy, hypernatremia
What are the indications for a stone analysis?
Nephrolithiasis: can help determine positive agent and aid inappropriate lifestyle modifications
What is the technique for a stoen analysis?
Stone sent to pathology: retrieved during cystography, collected after passage, surgically removed
What are the notes for a stone analysis?
Most common stone type is calcium oxalate
What are the indications for a stone panel?
Recurrent stone formation and to help determine factors that can be modified
What is the technique for a stone panel?
24 hr urine collection
