3. Urinary Catheters. Indications. Methods of Bladder Catheterization. Hashim Hashim

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1 3. Urinary Catheters Hashim Hashim Indications Urinary catheters are used to drain urine from the bladder. The main indications are: A. Diagnostic Measure post-void residual in the absence of ultrasound scanning Urine sample for evaluation by culture and microscopy in patients who are unable to void Measure urine output in critically ill patients B. Investigational Filling the bladder prior to ultrasound investigation of the abdomen Urodynamics Cystograms C. Therapeutic During labor when epidural anaesthesia is used Urinary retention (e.g., secondary to bladder outlet obstruction) Intractable urinary incontinence Major surgery (e.g., hip surgery, abdominal and pelvic surgery) Instillation of chemotherapeutic agents (e.g., mitomycin C and bacillus Calmette-Guérin [BCG]) Patients who are not fit for or do not want medical or surgical treatment for their bladder conditions Methods of Bladder Catheterization Four methods of draining or collecting urine from the bladder exist. Their use depends on patient s condition, availability of catheters, as well as local expertise and support. 1. Condom catheters: A condom is attached to the catheter and a drainage bag so that men can void through the penis into the condom and the urine is collected in the drainage bag. 2. Clean intermittent self-catheterization (CISC): Uses lubricated sterile catheters that are inserted by the patient though the urethra on an as

2 3. Urinary Catheters 17 required basis to drain urine. They need manual dexterity to be inserted. 3. Intra-urethral catheterization: These are self-retaining catheters used to continuously drain urine from the bladder and inserted via the urethra. 4. Suprapubic catheterization: A catheter is inserted through the skin in the lower anterior abdominal wall and into the bladder (see Chapter 25). Classification of Urinary Catheters Intra-urethral and suprapubic catheters can be classified according to their size, material, type of tip, position of holes, number of lumens, as well as the number and volume of inflatable balloons. There are also catheters without balloons. A. Size Many catheter sizes are available. The choice depends on the patient and the indication of use. Size is measured in: Charrière (Ch) units: catheter s diameter in millimeters (1 Ch = 0.33 mm diameter French (Fr) units: catheter s circumference in millimeters (12 Fr = 12-mm circumference) The length of catheters can be: Pediatric: 30 cm Female: 26 cm (20 26 cm) Standard: 43 cm (41 54 cm) You should only use standard catheters for men. B. Material Latex (rubber) Soft and flexible All rubber uncoated: short-term use up to 4 weeks Does not have a smooth surface, causing high surface friction Polytetrafluoroethylene (PTFE)-coated Inert Provides a smooth outer surface Can remain in situ for up to 4 weeks Silicone elastomer-coated Less prone to encrustation Compatible with the urethral mucosa Can remain in situ for up to 12 weeks Hydrogel-coated Absorb fluid, thus form a hydrophilic slippery cushion between urethra and catheter surface reducing trauma Resists encrustation and bacterial colonisation Can remain in situ for up to 12 weeks

3 18 The Handbook of Office Urological Procedures Silver-alloy coated: can reduce infections in the short-term Silicone 100% latex free: used in those with latex allergy Thin-walled Have wider drainage lumens Compatible with the urethral mucosa Lack flexibility High surface friction Can remain in situ for up to 12 weeks Can be hydrogel coated Plastic or polyvinylchloride (PVC) Relatively cheap Develop cracks and quickly encrust Short-term use (e.g., CISC) Rigid at temperatures lower than body temperature and therefore can cause discomfort Thin-walled with the widest lumens C. Tip and Holes (Figure 3.1) Straight: no bends at the tip Ordinary straight: holes on the side Couvelaire (whistle-tip): straight with openings lateral and distal to the balloon, providing a large drainage area to drain debris and blood clots Council tip: have a small hole at the tip, which allows them to be passed over a wire Straight Couvelaire Delinotte Dufour Figure 3.1. Catheter Tips and Holes.

4 3. Urinary Catheters 19 Figure 3.2. Single-Lumen Catheters. Coude: Bent/curved tip (approximately 45 ) to allow passage through prostate Delinotte (Mercier): a bent straight-tip Dufour: a bent couvelaire D. Lumens One lumen Nelaton catheters (Figure 3.2): a simple straight tube with (a) hole(s) at the end. These are mainly used for CISC. These catheters do not normally have an inflatable balloon. Malécot or DePezzer catheters (Figure 3.3): These have a triangular-/mushroom-looking tip designed for suprapubic catheterization or to drain urine from the renal pelvis. They are without a balloon, and therefore will stay in position because the tip will fold out once the stick inside the lumen of the catheter is retracted. Two lumens (Figures 3.4) Figure 3.3. Malecot Catheter. Figure 3.4. Two-Way Foley Catheter with Balloon Inflated and Deflated.

5 20 The Handbook of Office Urological Procedures Drainage arm Balloon inflation arm Irrigation arm Figure 3.5. Three-Way Catheter. Foley catheters: Two-way catheters with a tube and a balloon at the end to keep them from falling out of the bladder. Three lumens (Figure 3.5) Hemostatic catheters: Three-way catheters are generally thicker than the previous two catheters with an extra small separate channel. This allows fluid/irrigant to pass to the tip of the catheter and into the bladder to flush it and wash away blood and small clots through the primary arm that drains into a collection device. The inflation arm has a small plastic valve that allows for the introduction or removal of sterile water through a very small channel to inflate or deflate the retaining balloon. Four lumens (Figure 3.6) Figure 3.6. Four-Way Catheter.

6 3. Urinary Catheters 21 Figure 3.7. Two-Balloon Catheter. Three of the four lumens act as drainage conduit, inflation and deflation valve, or continuous irrigation port while the fourth lumen provides irrigation or aspiration of the operative site (e.g., following a transurethral resection of the prostate). E. Number and Volume of Balloons The maximum volume the balloon can accommodate is normally printed on the side of one of the arms. This can range from 5 40 ml. Most catheters have one balloon; however, there are some catheters that have two balloons (Figure 3.7). They are normally used after prostatectomy, and the second balloon sits in the prostatic capsule/fossa to help with tamponade of bleeding vessels. The bladder balloon is generally inflated first and the catheter pulled to the bladder neck and then the prostatic balloon is inflated. Complications of Urinary Catheters Discomfort Bladder spasms Catheter-associated urinary tract infections Trauma resulting in urethral strictures, false passages, and hematuria Bowel injury and perforation of the bladder Paraphimosis Urine leakage around the catheter Calculi formation

7 22 The Handbook of Office Urological Procedures Fragmentation and fracture of the catheter Bladder cancer in long-term use of catheters (rare) Reference 1. Ramakrishnan K, Mold JW. Urinary catheters: a review. Internet J Fam Pract 2005;Vol 3;2.