PRACTICAL TASK - CATHETERISATION 

Introduction
Urinary catheterisation may be carried out for a number of reasons:

1.  
   • To empty a patient's bladder prior to surgery.
   • To relieve a patient suffering a blockage to the urinary tract.
   • To perform hydroprepulsion to dislodge crystals.
   • To affix a urine collection bag to avoid soiling of a recumbent patient.
   • To accurately assess urine output.
   • To introduce contrast media for radiographic definition.
   • To collect a sample for urinalysis.

Dogs can usually be catheterised consciously or under mild sedation, while cats generally require sedation or general anaesthesia.

Preparation

1. Establish the species and sex of the patient. This will determine the type and size of catheter required.
2. Establish the reason for catheterisation since additional equipment may be required (see checklist).
3. Choose the correct type and size of catheter. Common examples are listed below.

   STANDARD CAT CATHETER
   Sizes - 3Fg and 4Fg.
   Material - Flexible nylon.
   Suitability - Both queens and toms.
   Comments - Not designed to be indwelling.

   JACKSON CAT CATHETER
   Sizes - 3Fg and 4Fg.
   Material - Flexible nylon.
   Suitability - Both queens and toms.
   Comments - Specially designed to be indwelling; therefore shorter than standard cat catheter with plastic phlange for suturing into place.

   DOG CATHETER
   Sizes - 6Fg, 8Fg and 10Fg.
   Material - Polyamide.
   Suitability - Best used for male dogs, but can be used in bitches if no alternative is available.
   Comments - Not designed to be indwelling but can be adapted.

   FOLEY CATHETER
   Sizes - 8Fg-16Fg.
   Material - Teflon coated latex.
   Suitability - The preferred catheter for bitches.
   Comments - May be temporary or indwelling; the inflatable balloon helps to secure the catheter in place.

   TIEMANS CATHETER
   Sizes - 8Fg-12Fg.
   Material - PVC.
   Suitability - Bitches only.
   Comments - The curved tip aids placement, not indwelling.

   SILICON CATHETERS

   It is important to remember that the Foley and Tieman catheters do not have a Luer mount and therefore an adapter will be required if a syringe is to be attached.

    

4. Prepare the equipment:

   GENERAL
   Protective gloves and apron.
   Catheter (with stylet if applicable).
   Lubricant (K-Y jelly or Xylocaine).
   Antiseptic and swabs for cleaning prior to catheterisation.
   Luer adapter if required.
   Receptacle to collect expressed urine.
   Syringe to draw off urine.

   Additional equipment may be necessary:

   URINALYSIS
   Sterile container such as a 30ml Universal plain (or Boric acid for bacteriology).

   BITCHES
   Vaginal speculum.
   Auroscope or other light source.
   Sterile water or saline and syringe for inflation of balloon of Foley catheter.

   CONTRAST RADIOGRAPHY
   3 Way tap.2ml/5ml.
   Syringes.
   Water soluble iodine (Eg Conray).

   INDWELLING CATHETER
   Luer mount or spigot.
   Collecting tube such as an adapted giving set.
   Collecting bag such as an empty drip bag.
   Zinc oxide tape, needle and suture material.
   Elizabethan collar.

In all cases, an assistant to restrain/position the animal will be necessary. Antibiotics must be administered in all cases of catheterisation.