There are several conditions such as retention of urine, residual urine, irrigation of the bladder, etc which needed urethral catheterization. This 
following article describes about principle prosedures requirement for male urethral catheterisation due to evacuate urine or to instill fluids.
This procedure may be undertaken by a physician or nurse who has been assessed as competent in carrying out this procedure by a suitably qualified and competent nurse, eg. Urology Nurse Practitioner. You can find sections that describe instructions, equipments, the actions and its rationale (in table view).
Just complete your read about Principle Prosedures for Male Urethral Catheterization – a Guideline in pdf filetype available to download (source: ashfordstpeters.nhs.uk, image: apps.med.buffalo.edu)
