Retention Flashcards
what are the causes of acute urinary retention?
Prostatic obstruction, urethral structure – STD, anticholinergics, “holding”, Alcohol, Constipation, post-op (pain/inflammation/anaesthetics), Infection, Neurological (cauda equina), Carcinoma, iatrogenic (cystoscopy scarring)
what is the underlying mechanism of acute urinary retention?
obstruction or decreased detrusor power
what are the investigations for acute urinary retention?
- Examine: abdomen, DRE, perianal sensation
- Tests: MSU, U&E, FBC, PSA
- Renal US
how is acute urinary retention managed?
- Tricks to aid voiding
- Catheterisation + start an alpha blocker (tamsulosin 400micrograms/d PO)
- Clot retention – 3 way catheter and washout
- If >1 L residual check U&E and monitor for post obstructive diuresis
- Prevention – finasteride, tamsulosin
what are the causes of chronic retention of urinary retention?
BPH, pelvic malignancy, rectal surgery, diabetes CNS disease (transverse myelitis/MS, zoster)
Neurological - UMN and LMN
what are the clinical features of chronic urinary retention?
- Insidious, Painless, Bladder capacity >1.5L
* Presentation: overflow incontinence, acute on chronic retention, lower abdominal mass, UTI or renal failure
what is the management of chronic urinary retention?
only catheterise if there is pain, infection or renal impairment
how is flow rate measured?
patient is asked to wee into a container that is attached to a graph printer
how is post void residual volume measured?
• The patient is asked to fully void themselves, and then a catheter is inserted to measure the post-void residual volume.
what is a normal flow rate?
A normal urinary flow graph rises quickly, and reaches a peak flow rate of about 20-25ml/s, before declining quickly again
what does sphincter EMG measure?
measures the electrical activity of the external urethral sphincter. This is a measure of the muscle tone of this sphincter.
what is cystometry?
measures the contractile force of the bladder whilst voiding
how is cystometry measured?
A catheter is inserted that can measure the pressure in the bladder, and can also squirt liquid into the bladder. The patient will be asked to note when they can feel their bladder filling as the catheter fills the bladder with saline. They will also be asked to note when they feel the urge to urinate. Pressure measurements will be taken as the patient voids.
