FREQUENTLY ASKED QUESTIONS
FOR ADVANCED PRACTICE PROVIDERS & CLINICIANS
How do I know if it's obstruction or detrusor underactivity?
Look at Pdet and Qmax. High Pdet with low Qmax = obstruction.
Low Pdet with low flow = underactive or acontractile bladder.
When do I really need to use a rectal catheter?
Always. It's critical for calculating Pdet and spotting straining.
Without Pabd, your pressure values are unreliable.
How do I know if the EMG is valid or just artifact?
Valid EMG shows quiet baseline and drops during void.
Random spikes or flat lines with no response are often artifacts.
Why did the patient say they couldn't void, even though they felt full?
Could be overfilled, anxious, or non-relaxing sphincter.
Slow fill, coach calmly, and allow privacy during voiding.
How much should I fill the bladder, and how fast?
Fill slowly—about 10-30 mL/min. Rapid fills cause false urgency
and overactive readings. Let the bladder respond naturally.
Is that spike detrusor overactivity (DO) or just movement?
Check the EMG and Pabd. If EMG and Pabd are flat but Pves spikes,
It's likely true DO. If all spike, It's movement artifact.
Can I do a good study if the patient has a foley or suprapubic catheter?
Yes, but results may vary. Insert urodynamic catheter through foley
or use suprapubic for vesical pressure. Expect compliance issues.
What does it mean if the bladder doesn't contract at all?
Could be acontractile bladder due to age, diabetes, or a neurological condition. Interpret with history and counsel on clean intermittent catheterization (CIC) options.
What's a normal EMG pattern during voiding?
Baseline EMG should be quiet. It should drop just before voiding.
A persistent high EMG during void suggests dysfunction.
Can I interpret this test myself, or should the doctor do it?
You can interpret basic patterns: flow, pressures, EMG behavior.
Always escalate abnormal or complex cases to the physician.
PHONE
Vickey Clark: 770-841-5144
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Dalena Coleman: 770-841-4463
