Diagnostic Testing Flashcards
1
Q
Sxs of testosterone deficiency in adult males?
A
- decreased: energy, libido, muscle mass, body hair
- hot flashes, gynecomastia, infertility
2
Q
Source of testosterone? Negative feedback loop?
A
- produced in testes by Leydig cells
- LH stimulates production
- negative feedback loop: testosterone inhibits production of LH and FSH
- single most impt dx test for male hypogonadism
3
Q
What tests should be ordered if you suspect hypogonadism? Diff in causes of increased and decreased SHBG?
A
- 1st: serum total testosterone (Normal range: 300-800 ng/dl)
- abnormal testosterone binding to sex hormone bidning globulins ( may need free testosterone test) - if SHBG increased then less free testosterone - aging, hyperthyroidism, increased estrogen, liver disease, HIV, anti-seizure drugs
- if SHBG decreased then more free testosterone - obesity, insulin resistance, T2DM, hypothyroidism, increased GH, exogenous androgens, glucocorticoids, nephrotic syndrome
4
Q
When should testosterone be drawn? Results?
A
- collect sample at 8am when testosterone levels are highest
- if normal - stop testing
- if abnormal - repeat 1-2 more times to confirm
5
Q
What should be done if testosterone is low on 2 tests?
A
- check LH and FSH
- if testosterone low and FSH and LH high = primary hypogonadism - ex: klinefelter, cryptorchidism, varicocele. glucocorticoids
- testosterone low and LH and FSH not elevated = secondary hypogonadism - ex: T2DM, liver or kidney disease, aging
6
Q
What is PSA? Where can it be found? Fxn?
A
- prostate specific antigen
- secreted by epithelial cells of the prostate
- present in low levels in the serum
- present in the semen
- fxn is to liquify semen in seminal coagulum to allow sperm to swim freely
7
Q
Causes of an elevated PSA?
A
- BPH
- prostate cancer
- prostatic inflammation or infection
- perineal trauma:
rarely DRE
bike riding
sexual activity (persists for 48-72 hrs post) - indirect measure of prostate glandular size in men w/o cancer
- normal values increase w/ age
- values can vary by race: blacks have higher PSA levels than whites
8
Q
Causes of decreased PSA?
A
- obesity: elevated BMI levels may cause lower PSA levels
- delayed early detection may partially explain worse outcomes in obese men with early prostate cancer
- meds that reduce PSA:
5-alpha-reductase inhibitors: 50% or greater reductions
NSAIDs
statins (17.4%)
thiazides (26%)
9
Q
Use of PSA for prostate cancer?
A
- determine extent of cancer
- response to tx
- screening method for detection:
controversial
lacks sensitivity and specificity
10
Q
Why are normal values of PSA controversial?
A
- in past a value of less than 4 ng/ml was normal
- men with prostate cancer were found to have values of less than 4
- men w/o prostate cancer were found to have values greater than 4
- impt to follow trend - how much has PSA increased over the last yr?
11
Q
Diff studies of PSA?
A
- age specific reference ranges
- free vs total PSA: lower portion of free PSA may be correlated w/ more aggressive forms of cancer
- PSA velocity and PSA doubling time: rate of change in PSA values over time, time it takes to double PSA
- pro-PSA: more strongly assoc w/ prostate cancer than BPH
12
Q
Research on PSA screening?
A
- for q 1000 men ages 55-69 that get screening PSAs yearly for a decade- 100-120 get positive results leading to prostate bx
- 110 get prostate cancer - and of these at least 60 have tx complication, 4-5 die from prostate cancer and 5 die who weren’t screened
- 0-1 deaths from prostate cancer are avoided by screening - causes more harm than good
13
Q
What is PSA density (PSAD)?
A
- PSA levels are higher in men with BPH
- PSAD is sometimes used for men with BPH to try to adjust for this - amt of PSA should be proportional to size of prostate
- it measures volume (size) of prostate w/ TRUS and divides PSA number by prostae volume
- a higher PSAD indicates greater likelihood for cancer
14
Q
Use of PSA velocity?
A
- PSAV
- rate of change in PSA over time
- PSA that is rising quickly is more suspicous for cancer
- however a PSA that is already high or quickly rises to a concerning level will quickly lead to further eval
- usually with transrectal prostate bx
15
Q
What is Free/total PSA (PSAII)? BPH vs cancer findings?
A
- percentage of free PSA decreases as total PSA increases in serum of men with prostate cancer
- ratio of f/t PSA, especially in men w/ normal PSA values can be helpful in dx those w/ possible CA
- only useful when PSA 4-10 ng/dl
- if free PSA is elevated in respect to bound PSA - then PSA is probably being produced by BPH
- if there is high level of bound PSA then it is likely to be manufactured by prostate cancer cells
16
Q
USPSTF statement on PSA testing?
A
- small pontential benefit and significant potential harms - don’t screen pt with PSA test unless individual being screened understands what is known about PSA screening and makes personal decision that even a small possibility of benefit outweighs known risk of harms
17
Q
Impt of semen analysis? What needs to be done?
A
- remains mainstay in investigating male fertility potential
- abstain from coitus 2-3 days
- collect all ejaculate
- analyze w/in 1 hr
- obtained by masturbation
- provides immediate information
18
Q
What are the diff parts to semen analysis?
A
- macroscopic: viscosity, volume and pH - microscopic: spem concentration/count motility morphology viability (supravital stain) leukocyte count search for immature germ cells
19
Q
Normal semen analysis?
A
- volume: over 1 cc
- concentration: over 20 mill/cc
- initial forward motility: over 50%
- normal morphology: over 60%
20
Q
What is azospermia? oligospermia?
A
- azospermia: no measurable sperm in semen
- oligospermia: less than 15 mill/ml
21
Q
Causes of azospermia?
A
- klinefelters (1/500)
- hypogonadotropic-hypogonadism
- ductal obstruction (absence of vas deferens)
22
Q
Causes of oligospermia?
A
- anatomic defects
- endocrinopathies
- genetic factors
- exogenous (heat)
23
Q
Causes of abnormal volume of semen?
A
- retrograde ejaculation
- infection
- ejaculatory failure
- meds
24
Q
How is dx of chronic prostatitis made?
A
- analyzing specimens obtained following prostatic massage
- first periurethral area is cleaned and pt allowed to void
- initial 5-10 ml and midstream specimen are obtained for quantitative culture
- the pt should stop voiding b/f bladder is empty and prostate should be massaged - any prostatic secretions that are expressed should be cultured as well as first 5-10ml of subsequently voided urine
25
When should a prostatic massage be avoided?
- in acute bacterial prostatits
| - risk for induction of bacteremia or sepsis
26
How is a UTI dx?
- in adults and older kids - mid stream urine sample usually reliably represents the urine in bladder (clean catch)
- samples collected from urinary bags, pedi-bags or bedpans shouldn't be used to dx UTI as they are most likely contaminated
- most reliable sample is obtained via cath or or suprapubic aspiration in infants (often less traumatic than cath - do if unable to cath)
27
Traditional gold std for sig bacteriuria, test used for what pts?
- urine culture and sensitivity - over 100,000 cfu/ml of urine
- some argue criteria for bacteriuria is only 100 cfu/ml of uropathogen in sx females or 1,000 in symptomatic males
- bacterial identification from urine C&S - key in males and females w/ complicated UTIs
28
Methods of urine sensitivity?
```
- measurement of sensitivity of bacteria to abx
methods:
-agar diffusion:
kirby-bauer - discs
Etest - strips
-broth dilution
```
- solid media: disc diffusion technique
- liquid media: minimum inhibitory concentration (MIC) test
29
Presentation of bladder cancer? What tests do you want to run?
- pts usually present w/ painless hematuria (hallmark)
- Will get UA and some cytology
- real dx test: cystoscopy
(gold std: cystoscopy and bx)
30
How do you dx bladder cancer w/ cytology?
- microscopic cytology of urinary sediment or saline bladder wash to detect malignant cells ( saline bladder washes more accurate)
- microscopic cytology is more sensitive in high grade tumors or carcinoma in situ but can be falsely negative in 20% of cases
31
What is urodynamics? Who does this?
- bladder fxn
- peak flow urine rates: measures how fast urine is passed
- pressure flow study: urodynamic catheter in bladder, allows measurement of pressure and urine flow during voiding
- done by urologists
32
What is urodynamic assessment?
- used to assess how well bladder and urethra are fxning:
sphincter control
bladder filling/emptying
33
Indications for urodynamic assessment?
to assess sxs such as:
- urinary incontinence
- frequent urination
- sudden, strong urges to urinate
- painful urination
- problems starting a urine stream
- problems emptying the bladder
- recurrent UTI
34
What are the components of urodynamic testing?
- uroflometry
- post-void residual measurement
- cystometry:
measurement of bladder pressure
measurement of leak pt pressure
pressure flow studies
- electromyography
- video dynamics
35
What is uroflowmetry? Used for what pts?
- screening tool for pts with suspected bladder outlet obstruction
- measures peak flow in mL/sec
- reserved for pts with severe sxs where invasive therapy is considered - done by urologist
- ex of abnormal uroflow report: BPH - problems initiating and maintaining stream
36
When is post-void residual (PVR) used?
- when pt is unable to completely empty bladder: bladder obstruction (sig BPH), or women with cystoceles
- can use US or cath
- use after anesthesia
- normal values:
is under 50 ml
if pt is older than 60 normal: 50-100 ml
37
What is a cystometogram (CMG)? Assesses what?
- graphic display of vesical pressure: bladder is filled w/ water at steady state, pressure flow study compared w/ uroflow can distinguish bladder outlet obstruction from impaired detrusor fxn
- assesses:
detrusor activity
sensation
capacity
compliance
- rarely done - invasive - urologist referral
38
What is a urethral pressure profile? Indications for testing?
```
- measures urethral pressures at multiple levels
indications for testing:
-sphincter dysfxn
-urinary incontinence
-detrusor sphincter dyssynergia
```
39
What is video urodynamics?
- aka multichannel fluoroscopic urodynamics
- combines measurement of pressures w/ uroflow and EMG measurements under radiographic guidance to eval interplay b/t all these fxns
- invasive
40
Testing for chlamydia?
- NAATs detect small amts of chlamydia nucleic acid
- vaginal swab for women
- urine or urethral swab for men: urine ok for women too but vaginal sample more sensitive, rectal swabs may also be obtained
- some available NAATs include ability to detect Neisseria gonorrhea from same specimen
41
Testing for gonorrhea?
- males with suspected urethritis:
microscopy w/ gram stain of urethral swab performs well in men w/ suspected urethritis , noninvasive method: NAAT of urine
- females with suspected cervicitis or urethritis:
vaginal swab specimen has best overall sensitivity and specificity
42
HPV testing?
- women - pap smear
| - men: no approved HPV test for men - some use cervical swabs in anal region for eval of MSM
