GU Diagnostics Flashcards
(50 cards)
1
Q
Macroscopic Urinalysis
A
NORMAL:
- Color-pale to dark, yellow or amber & CLEAR
- Volume-750 to 2000 ml/24 hr
ABNORMAL:
- Turbidity/cloudiness-excessive cellular material or protein from crystallization or precipitation of salts
- Red/brown-food dye, beets, drugs, or presence of hemoglobin/myoglobin (if RBC’s, will be cloudy & red)
2
Q
UA: pH
A
Glomerular filtrate of blood plasma is acidified by renal tubules & collecting ducts
Normal = 4.5-8.0 depending on the systemic acid-base status
- -> high pH may indicate renal tubular acidosis (less habitable environment for bacteria)
- -> infections w/ urease producing bacteria (Proteus, Klebsiella)
3
Q
UA: Specific Gravity
A
Measurement of urine density–ability of kidney to concentrate or dilute the urine over that of plasma
- Proportional to urine osmolality
- Mediated by ADH
- NORMAL = 1.007-1.010
- Below –> hydration
- Above –> dehydration
NOTE: over 1.035 –> contamination, very high glucose, recent high density radiopaque dyes IV, or low molecular weight dextran solutions
4
Q
UA: Protein
A
Normally, small amounts of plasma proteins & nephron proteins (Tamm-Horsfall protein) is found in urine
- NORMAL = < 150 mg/24 hours or 10 mg/100 mL
- Proteinuria = > 150 mg/day
- Nephrotic syndrome: proteinuria > 3.5 gm/24 hours
5
Q
UA: Heme
A
If +, must f/u w/ a microscopic exam (positive = hematuria)
- Presence –> renal stones, renal disease, neoplasms, infarcts, trauma
- Contamination may occur from menstruation, catheter trauma
6
Q
UA: Leukocyte Esterase
A
Positive = pyuria = presence of WBC’s
- True pyuria = infection/bacteriuria
- Sterile pyuria = interstitial nephritis, renal TB, nephrolithiasis
7
Q
UA: Nitrites
A
Positive –> significant bacteria
- Produced from bacterial waste product*
- Enterobacteriacea species (E. coli)
- Pyridium (medication-induced nitrites)
8
Q
UA: Glucose
A
< 0.1% of glucose is normally filtered into the urine (NORMAL = < 130 mg/24 hr.)
- Glycosuria (excess urine) –> MC, DM
- Renal glycosuria
- Urinary spillage d/t abnormally high plasma glucose concentrations in DM (plasma typically >180 ml/dL)
9
Q
UA: Bilirubin
A
- Waste product of old RBC’s, normally removed by the liver in bile
- Presence in urine may be a sign of liver disease
10
Q
UA: Crystals
A
Uric acid, calcium phosphate, clacium oxalate, cystine, magnesium, ammonia phosphate (struvite)
Crystals common, even in healthy pts:
- Calcium oxalate
- Triple phosphate
- Amorphous phosphates
11
Q
UA: Microorganisms
A
Bacteria
- Bacteriuria: > 100,000/mL of one organism
- Multiple organisms indicates contamination
Fungi
-Yeast: MCC = Candida –> distinguished by their tendency to bud, colonize the bladder, urethra, or vagina
12
Q
UA: RBC’s
A
RBC’s may be normally shaped, swollen by dilute urine, or crenated by concentrated urine
- ABNORMAL = > 1 RBC
- 3+ RBC’s on 2 UA’s warrants referral to urology
- Dysmorphic RBC’s suggests glomerular disease
13
Q
UA: WBC’s
A
High WBC’s = PYURIA
- Presence –> infection, colonization (e.g. catheters), stones, interstitial nephritis, glomerulonephritis
- ABNORMAL = 2+ WBC’s per specimen
14
Q
UA: Epithelial Cells
A
- Renal tubular cells –> high w/ nephrotic syndrome or tubular degeneration
- Lipiduria –> renal tubular cells fill w/ fat droplets
- Transitional epithelial cells –> formed in the renal pelvis, ureter, or bladder
- Squamous epithelial cells –> from the skin surface or outer urethra (may indicate contamination)
15
Q
UA: Casts
A
*Formed only in the DISTAL convoluted tubule or collecting ducts (DISTAL nephron)
-Matrix = Tamm-Horsfall mucoprotein, albumin, & globulins
-Factors favoring cast formation:
Low flow rate
High salt concentration
`Low pH
16
Q
UA: Hyaline Casts
A
- HYALINE casts: composed of mucoprotein (Tamm-Horsfall protein) secreted by tubule cells in the collecting duct
- Can be seen in healthy pts
17
Q
UA: Protein casts
A
Long, thin tails formed at the junction of Henle’s loop & distal convoluted tubule
- AKA., “Cylindroids”
18
Q
UA: RBC casts
A
RBCs clump together
-Due to glomerulonephritis w/ leakage of RBCs from glomeruli, or severe tubular damage
19
Q
UA: WBC casts
A
Form d/t inflammation in the kidney
- MCC = pyelonephritis
- May also indicate glomerulonephritis
20
Q
UA: Granular casts
A
- Cellular casts that remain in the nephron for some time & are flushed into the bladder urine –> coarsely granular cast –> finely granular cast –> waxy cast
- Granular & waxy casts derive from renal tubular cell casts
21
Q
UA: Broad casts
A
- Form due to damaged & dilated tubules
- Indicate end-stage chronic renal disease
22
Q
UA: Telescoped Urinary Sediment
A
All types of casts (RBCs, WBCs, oval fat bodies) found in more or less equal profusion
Causes:
- Lupus nephritis
- Malignant HTN
- Diabetic glomerulosclerosis
- Rapidly progressive glomerulonephritis
Urinary sediment is very scant in end-stage kidney disease
23
Q
UA: Ketones
A
Due to:
- Diabetic ketosis
- Calorie deprivation (starvation)
24
Q
-
A
-
25
Urine Culture & Sensitivity
Standard definition of a + urine culture: > or equal to 100,000 colony forming units per mL + pyruria (leukocyte count > or equal to 100,000 WBC per mL)
-Sensitivity testing to ensure targeted antibiotic therapy
Exceptions--Acute Urethral Syndrome
- Fecal contamination r/o w/ irritative voiding symptoms
- Earlier stage of infection
- Bladder washout during normal micturition
26
Urine Cytology
- Detects new & recurrent urothelial tumors
* 34% sensitivity, 99% specificity
- Not widely used for screening d/t high cost & need of pathologist interpretation
- Used as surveillance in pts w/ hx of urothelial carcinoma & pts w/ suspicious sxs (e.g. HEMATURIA)
27
Prostate Specific Antigen (PSA)
Glycoprotein expressed by normal & neoplastic prostate tissue
- Serum test
- Screens for PROSTATE CANCER, extent of prostate cancer, & response to tx
- Begin screening at 50 y.o. IF life expectancy is > 10 years or at 40-45 y.o. w/ increased risk, strong family hx, or African American race
28
Prostate Cancer
- 2nd MC dx cancer in men (1st = non-melanoma skin cancer)
- 2nd MCC of cancer death (1st = lung)
- Lifetime risk = 16%
- Risk of dying from prostate cancer = 2.9%
- Autopsy series showed prostate cancer in 30-45% of men > 50 y.o. & 80% of men > 70 y.o.
29
Elevated Prostate Specific Antigen
Normal = 2.1-4.0 ng/mL
Elevations occur d/t:
1. Prostate cancer
2. Benign prostatic hypertrophy
3. Prostate infection or inflammation
4. Perineal trauma (e.g. straddling bike)
30
PSA Controversy
- Small absolute benefit after 9 yrs., non after 7 yrs.
- 48 pts would be dx to prevent once related death
- 25% w/ normal PSAs have prostate cancer
- US preventative task force advises against PSA screening
31
PSA: Potential Harm
- Over-diagnosis: dx cancers that would never cause clinical sxs; increasing lifetime risk (1/6), but stable risk of death
- Risks of biopsy: bleeding, infection, pain, anxiety
- Risk of prostatectomy: mortality, erectile dysfunction, urinary problems
- Risk of radiation therapy: ED, urinary incontinence, bowel dysfunction
32
Digital Rectal Exam
ø Utility: prostate cancer, prostatitis, BPH
ø Abnormal prostate findings: nodules, asymmetry, induration
ø Limitations: 85% of cancers in posterior/lateral aspects, stage 1 tumors are non-palpable, no reduction in morbidity or mortality when detected-majority are in advanced stage when palpable
ø DRE should be paired w/ PSA testing
33
Prostate Biopsy
ø Indications:
-Abnormal DRE, rising PSA-refractory to antibiotics, rapid PSA rise, repeat for inadequate initial sampling
ø Procedure: urologist, transrectal ultrasound guidance, template-guided to ensure uniform sampling, pre-procedure antibiotics
ø Risks: infection, bleeding (hematuria, rectal, or hematospermia), drug resistant bacteria
34
Serum Creatinine
* Breakdown product of creatine phosphate in muscle, usually produced at a constant rate, depending on muscle mass*
- NORMAL: female-0.5-1.0 mg/dl, male-0.7-1.2 mg/dl
-Factors affecting result:
ø race
ø muscle mass-amputees, malnutrition, muscle wasting
ø diet-vegetarian, creatine supplements
35
Serum Blood Urea Nitrogen (BUN)
- Byproduct (ammonia-containing nitrogen) of liver protein degradation
- Nitrogen combines w/ carbon, hydrogen, & oxygen to form urea --> travel to kidney for excretion as urine
BUN elevations:
ø renal dysfunction, increased protein intake, dehydration, poor circulation
BUN decreases:
ø liver disease or damage, malnutrition
36
BUN:Creatinine Ratio
NORMAL: 10-20:1
ø possible post-renal etiology
INCREASED: >20:1
ø BUN reabsorption is increased
ø Pre-renal etiology--dehydration, decreased blood flow due to CHF, GI bleeding, increased dietary protein
DECREASED: <10:1
ø renal damage causes reduced reabsorption of BUN
ø etiology--intrarenal etiology (glomerulonephritis, acute tubular necrosis), liver disease, malnutrition
37
Glomerular Filtration Rate (GFR)
ø Utility: assess degree of kidney impairment, follow course of kidney disease
ø GFR = sum of filtration rates of all functioning nephrons (~180 liters per day; 125 mL/min of plasma)
--normal value depends on age, sex, body size (men = 130 mL/min, women = 120 mL/min)
ø Reduction in GFR = progression of underlying renal disease or development of a superimposed & often reversible problem (e.g. decreased renal perfusion d/t volume depletion)
38
GFR: Limitations
ø No information on cause of kidney disease
ø No exact correlation b/t loss of kidney mass & loss of GFR--kidney adapts by compensatory hyper filtration and/or increasing solute & water reabsorption in the remaining, normal nephrons
ø Measurement is complex & time consuming
ø Usually estimated from serum markers
39
Cockcroft-Gault Equation
ø Creatinine clearance estimated from serum creatinine
ø Accounts for decreased creatinine production w/ advancing age & weight
ø Limitations: cannot account for rapidly changing GFRs, increased weight does NOT equal increased muscle mass, not adjusted for body surface area, 10-40% overestimation of creatinine
40
Renal Biopsy
Goal:
ø establish a dx, guide therapy, & ascertain degree of active & chronic changes
Indications:
ø hematuria w/ proteinuria or renal insufficiency, unexplained acute renal failure, idiopathic nephrotic syndrome, systemic lupus erythematosus, acute nephritic syndrome, renal transplant rejection
41
Percutaneous Renal Biopsy: Prebiopsy Evaluation
- H+P, controlled BP
- No skin infection at biopsy site
- Lab tests: CMP, CBC, platelets, PT, PTT, bleeding time
- Renal US: assess size of and/or presence of any anatomic abnormalities
- Hold ASA, NSAIDs, antiplatelet or antithrombotic agents for 1-2 weeks prior to biopsy & for 1-2 weeks after biopsy
42
Percutaneous Renal Biopsy: Technique
- Consent & IV access
- Pt prone w/ pillow under abdomen
- Ultrasonic guidance w/ local anesthesia
- Locate lower pole, mark skin, sterilely prep site
- Inserte anesthesia into the capsule, make skin incision, & insert biopsy needle
43
Percutaneous Renal Biopsy: Complications
1. Bleeding
ø into the collecting system (hematuria, ureteral obstruction), underneath the renal capsule (pressure tamponade, pain), into perinephric space (hematoma, fall in hematocrit)
ø bleeding occurs within 12-24 hours
2. Puncture of renal artery, aorta, or venous collaterals
3. Pain > 12 hours
4. Arteriovenous fistula
5. Perirenal soft tissue infection
6. Puncture of liver, pancreas, or spleen (rare)
44
Percutaneous Renal Biopsy: Post-biopsy Monitoring
- Supine for 4-6 hours
- Remain on bed rest overnight
- Monitor vital signs, UA, CBC
- Control BP <140/90 mmHg
- Monitor for 24 hours
45
Catheterization
Urethral or Suprapubic
Indications:
- Obtain a sterile urine specimen
- Measure residual urine volume
- Relieve urinary retention or incontinence
- Deliver radiopaque contrast agents or drugs directly to the bladder
- Irrigate the bladder
46
Catheters
Vary by caliber, tip configuration, number of ports, balloon size, type of material & length
Caliber
- Standardized French (F) units
- 0.33 mm per French (ie. 14 F = 4.6 mm in diameter)
Tip configuration
- Straight tip for CIC or Foley drainage
- Coude tip (elbowed, curved) for strictures or obstruction
- Malecot (4-winged, expanded) for SPT or nephrostomy
47
Urethral Catheterization-Complications
Relative contraindications
- Urethral strictures
- Current UTI
- Urethral reconstruction or bladder surgery
- Urethral trauma
Complications
- Urethral or bladder trauma with hematuria
- UTI (common)
- Creation of false passages
- Scarring and strictures
- Bladder perforation (rare)
48
Sexually Transmitted Infections: H+P
5 P’s:
- Partners
- Prevention of pregnancy
- Protection from STIs
- Practices
- Past history of STIs
49
STI's: Diagnostic Studies
Serum studies
- HIV
- Hepatitis B & C
- Syphilis
- Herpes simplex
Urine studies
- Gonorrhea
- Chlamydia (MC STI)
- Trichomoniasis
HPV
- Typically observed on physical exam
- Recommend annual anal pap test for gay, bisexual and HIV-positive men (d/t increased risk of anal cancer)
50
GU: "Other" diagnostic markers
ø Testes tumor markers: AFP, bHCG, LDH
ø Urine fungal cultures: ureaplasma, mycoplasma
ø Infertility evaluation: semen analysis, testosterone, LH, FSH, testes biopsy
ø Other urinary organisms: schistosomiasis (“worms” in the urine), TB
