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Catheterising bladders

The passage of a urinary catheter should not be undertaken lightly but it is a procedure that often has to be done. Nurses are often competent in the procedure, including female nurses doing male catherisation but a doctor may be called upon to undertake it at times and that doctor should be confident and competent.

NICE have made a number of recommendations about urinary catheters.¹

Indications: It is important to be clear about the indication before starting.

• Acute retention of urine
• Chronic retention of urine
• Prophylactic emptying of the bladder as before a pelvic operation such as hysterectomy of caesarean section or an instrumental delivery
• Incontinence
• To monitor urine output or assess residual volume
• Management of a neuropathic bladder

The indication will influence the choice of catheter.

• For simple preoperative catheterisation, including before forceps delivery, a silver catheter is preferred.
• If the bladder is to be emptied and the catheter removed a Jacques or Nelaton catheter is employed.
• If the catheter is to be left in situ an indwelling Foley catheter is used.
• A silicon Foley catheter has a much longer life than a latex-silicon one and so is preferred when a catheter is to be left long term.
• There are other types including 3-way catheters for bladder irrigation and there are different tips.

Risk factors: Having a catheter in situ is a risk factor for urinary tract infection but the time of greatest risk is the time of insertion of the catheter. This is one reason for silicon catheters as they reduce the number of times a year that a catheter has to be changed. Nevertheless, there may still be good indications for intermittent rather than indwelling catheters. With an indwelling catheter, bacteriuria becomes almost inevitable and if there are no symptoms this is no reason for concern. Antibiotics will not clear an infection whilst the foreign body remains in situ but they do increase resistance.² Bandolier have made a number of recommendations about avoiding infections.³.

Sometimes there can be difficulty inserting a catheter, especially if there are problems such as urethral stricture, carcinoma of prostate or after trauma. In such cases, rather than persevering it is more judicious to seek help from one with greater experience of urology. The uninitiated should not use introducers and suprapubic catheterisation is also best left to the more experienced practitioner. Catheters come with various tips. The standard straight is suitable for most occasions. Beware of types such as the Tieman tip that is a German style that is designed to facilitate passage through the prostate. It is easy to produce false passages and to do much damage.

Catheter materials:

• Jacques or Nelaton catheters are usually made of PVC.
• The original Foley catheters were made of latex rubber but this has become obsolete.
• Silicone latex Foley catheters are very similar, but have a silicone layer on top of the latex. The latex surface of catheters was shown to irritate the urothelium of the urinary tract and this could lead to microscopic lacerations and later development of strictures. Some patients are allergic to latex. These catheters are slightly more expensive than the standard ones. The silicone layer tends to get damaged after a while and the underlying latex may again come into contact with the urothelium, which restricts the use of silicon latex catheters to 1 to 2 weeks when they should either be removed or replaced.
• Silicone Foley catheters are 5 to 10 times as expensive as the silicon latex but their relative price has fallen as they have become more popular. A plain silicone catheter may be transparent, white, blue, green or other colours. As well as having a longer life of 6 to 8 weeks, they are more rigid and this can be advantageous. Some manufacturers claim a life of up to 3 months. The balloon tends to empty by loss of water due to a semi-membranous effect of the wall of the balloon and so it will need to be refilled periodically. With a long life, encrustrations tend to form at the tip of the catheter which may lead to narrowing of the orifice or an increased diameter, that may cause pain and bleeding upon removal. Therefore, they should not be left beyond the recommended limit.
• Other materials are being developed.⁴

Technique: The techniques for male and female catheterisation will be different as the anatomy is so different but both must be an aseptic no-touch technique. A no touch technique does reduce the risk of introducing infection into the bladder.⁵ Try to touch only the plastic tube that contains the catheter and not the catheter. Before starting check that all the necessary equipment is present. It is usual to have the patient in a supine position. For both men and women a size FG 16 or 18 is usually suitable. Smaller sizes are suitable for children. If a catheter is being replaced, note the size of the one to be removed.

• Sterile gloves
• Suitable antiseptic
• Swabs or cotton wool
• Sterile paper towels
• Antiseptic, anaesthetic lubricating gel
• Appropriate range of catheters
• Receptacle for urine of if the catheter is to be left in situ a urine bag with tube to connect to the catheter
• If a Foley catheter is to be used, a syringe of appropriate size and water or saline for the bulb are required. Note the capacity of the bulb before starting.

Male catheterisation:

• Retract the prepuce if the patient is uncircumcised and there is no phimosis. Use antiseptic liquid to clean the glans.
• Grasp the penis with index finger and thumb just behind the rim of the glans and then stretch it straight up. This will stretch the first curve in the urethra.
• Insert a few ml of gel into the urethra, using the insertion device for that purpose, and be sure to spill a little on the surrounding glans so that it will lubricate the catheter on its way in.
• Some people connect a collecting bag to the catheter before insertion so as not to wet the bed when the urine starts to flow. Others use a small collecting bowl and when flow starts they kink the tube to obstruct it and then connect the bag.
• Let the catheter slide gently but firmly into the urethra until there is a soft resistance that is the second curve in the urethra.
• Turn the stretched penis downwards, while pushing against the catheter. When needed, the penis may be turned further downwards, against the bed, to be able to pass the catheter along the prostate in a slightly upward direction.
• Push the catheter in further when urine is achieved. This is important to prevent the balloon from being inflated whilst still in the prostate.
• If a Foley catheter has been inserted, the balloon should be filled with the appropriate amount of water or saline. This is usually 10 to 15ml. The catheter should then be gently retracted from the urethra until there is a slight tug to indicate that the balloon rests against the bladder neck or prostate. Urine should now be flowing freely. If it is not, possibly because the bladder is too atonic, pressure on the bladder should induce flow.
• Replace the prepuce. If this is not done a paraphimosis will result. If an indwelling catheter has been passed it is often helpful to tape the tube to the inner thigh so that any tug on the tube pulls on the tape rather than on the catheter in the bladder.

Common problems:

• If there is phimosis and the opening is adequate, try to pass the catheter blind. If the opening is too narrow try dilating it with sounds or try a smaller catheter. If in doubt seek more expert help.
• If the catheter will not pass the prostate, try a catheter with a larger diameter. The urethra at the site of the prostate is not narrow, but it is pushed flat by the surrounding prostate. A larger catheter pushes the prostate lobes back to the side to allow passage. Another option is to try a silicone catheter as it is more rigid than a silicon latex catheter.
• If the catheter does not pass the bladder neck try a smaller size.

Female catheterisation: The female urethra is much shorter and without such problems as the prostate but identifying the urethral orifice can be difficult.

• Wipe the area around the urethra with antiseptic.
• Lubricate the catheter tip generously with gel. Spread the labia and let the catheter gently slide inside.
• Some people connect a collecting bag to the catheter before insertion so as not to wet the bed when the urine starts to flow. Others use a small collecting bowl and when flow starts they kink the tube to obstruct is and then connect the bag.
• If the urethral opening is not visible, try to feel for it just around the corner at the anterior side of the vagina where it can then often be felt as a small horse-shoe like rim. Place the tip of the catheter on the index finger and let the tip slip into the opening.
• Push the catheter about 10 cm into the bladder to ascertain that it is truly in, and to allow some slack when the hands shift position to fill the balloon.
• If a Foley catheter is used, the balloon should be filled with the appropriate amount of water or saline. The catheter should then be gently retracted from the urethra until there is a slight tug to indicate that the balloon rests against the bladder neck. Usually, nearly all of the catheter tube will protrude from the urethra. Urine should now flow. If it does not because of an atonic bladder, pressure on the bladder will start the flow.
• If an indwelling catheter is used, tape the tube to the inner thigh so that any tug will pull on the tape rather than the catheter.

Common problems:

• A false passage may occur, especially if a traumatic catheterisation has occurred. Sometimes the urethra has been missed and the catheter inserted into the vagina.
• If too small a catheter has been used, it may become blocked because of its small lumen, leading to urinary retention. The small diameter allows the catheter to move around and bulge and slide inside the urethra, causing scratches and damages to the urothelium, producing irritation in the short term, but later it may lead to urethral strictures.

Prophylactic antibiotics: A Cochrane review of antibiotic policies for short-term catheter bladder drainage in adults concluded that there was weak evidence that antibiotic prophylaxis compared to giving antibiotics when clinically indicated reduced the rate of symptomatic urinary tract infection in female patients with abdominal surgery and a urethral catheter for 24 hours. There was also limited evidence that prophylactic antibiotics reduced bacteriuria in non-surgical patients.⁶ General opinion is that the use of prophylactic antibiotics is to be depreciated.⁷ but prevention of UTI is not the only potential problem. The procedure may induce bacteraemia and an American study of children under 24 months old who required urinary catheterisation in the presence of bacterial endocarditis suggested that prophylaxis was not cost-effective.⁸ Bacteraemia is not the same as septicaemia. A review from Leicester found that urinary tract instrumentation is a significant cause of septicaemia.⁹ Review of the literature suggests that selective use of antimicrobials would reduce the risk of septicaemia as this varies between patients and with procedures. Antimicrobial prophylaxis is indicated for patients at high risk of endocarditis, or who are neutropenic. Single dose aminoglycosides or oral fluoroquinolones are the agents of choice with the exception of the prevention of endocarditis, where combinations active against streptococci are recommended. For other instrumentations, the risk of antimicrobial toxicity probably outweighs the benefits and a risk-reduction strategy is recommended. An audit found that gentamicin was often given at or after catheterisation and this is too late to be effective.⁷

Removal of a catheter: Traditionally an indwelling catheter is removed early in the morning so that if micturition does not follow this will be apparent during daytime hours and the catheter can be replaced. A valid alternative is to remove it just before the patient goes to sleep at night. It is usual to empty the bladder before retiring and to sleep through the night and it is only if a full bladder cannot be emptied in the morning that the catheter is replaced. What is important is to choose a time so that if voluntary micturition does not occur, that no one is called from bed to replace the catheter.

• When the time comes to remove the catheter, attach a syringe to the orifice to the balloon and draw back on the plunger to suck out the water or saline in the balloon and then gently pull the catheter out.
• If the balloon will not empty, try being more gentle with traction on the plunger of the syringe as excessive pressure may have collapsed the tube so that water will not flow.
• Try instilling another 1 or 2 ml of water to unblock any adhesions.
• Try wiggling and rotating the catheter whilst pulling the plunger.
• Cut the catheter a little way outside the urethra. Be careful that the catheter does no retract and disappear into the bladder. It may be necessary to insert a safety pin through it to prevent this and leave the catheter for an hour or two whilst the balloon slowly empties.
• If the balloon remains rigid, it may be possible to locate and puncture is by digital examination and use of a prostatic biopsy needle. This is done through the rectum in men and the vagina in women.
• It may be possible to overinflate the balloon and burst it. If this is done is should be followed by cystoscopy as to ascertain that no pieces are left in the bladder.
• Ether should not be used. It is said that injecting a small amount of ether into the balloon will destroy the latex but it is probably rather faster than that and causes an explosion. The boiling point of diethyl ether is 34.6º. Therefore, when it is brought up to body temperature it boils with an enormous expansion and increase in pressure. Ether is very irritant to the bladder.

Suprapubic catheterisation: The technique is not described here but may be found on the University of Leuven website, listed below.

References:

1. NICE Infection control, February 2003.
2. Nicolle LE; Catheter-related urinary tract infection.;Drugs Aging. 2005;22(8):627-39.[abstract]
3. Bandolier Preventing catheter-related bacteriuria, September 1999.
4. Shaw GL, Choong SK, Fry C; Encrustation of biomaterials in the urinary tract.;Urol Res. 2005 Feb;33(1):17-22. Epub 2004 Dec 22.[abstract]
5. Hudson E, Murahata RI; The 'no-touch' method of intermittent urinary catheter insertion: can it reduce the risk of bacteria entering the bladder?;Spinal Cord. 2005 Oct;43(10):611-4.[abstract]
6. Niel-Weise BS, van den Broek PJ; Antibiotic policies for short-term catheter bladder drainage in adults.;Cochrane Database Syst Rev. 2005 Jul 20;(3):CD005428.[abstract]
7. Fraczyk L, Godfrey H; Current practice of antibiotic prophylaxis for catheter procedures.;Br J Nurs. 2004 May 27-Jun 9;13(10):610-7.[abstract]
8. Caviness AC, Cantor SB, Allen CH, et al; A cost-effectiveness analysis of bacterial endocarditis prophylaxis for febrile children who have cardiac lesions and undergo urinary catheterization in the emergency department.;Pediatrics. 2004 May;113(5):1291-6.[abstract]
9. Olson ES, Cookson BD; Do antimicrobials have a role in preventing septicaemia following instrumentation of the urinary tract?;J Hosp Infect. 2000 Jun;45(2):85-97.[abstract]
10. Moog FP, Karenberg A, Moll F; The catheter and its use from Hippocrates to Galen.;J Urol. 2005 Oct;174(4 Pt 1):1196-8.[abstract]
11. Moog FP, Karenberg A, Moll F; The catheter and its use in late antiquity and the early middle ages.;J Urol. 2005 Aug;174(2):439-41.[abstract]
12. Abdel Halim RA Urethral Catheters: A Historical Review Saudi Medical Journal 1990; 11 (2): 87-88.

Internet:

• Bladder catheterisation Belgian website from the University of Leuven but good, clear English and useful diagrams.
• www.madehow.com Catheter

History: Catherisation of the bladder dates back to the 5th century BC and includes such notable names as Hippocrates, Celsus, Soranus, Rufus, Aretaeus and Galen.¹⁰ Catheters were also used in late antiquity and the middle ages.¹¹ The ancient Egyptians may have used catheters as early as 4000 BC. In the Graeco-Roman era and in the Middle Ages in Europe, S-shaped bronze catheters with one terminal eye were in common use. In the Middle East, Moslems developed them further and by 1013, straight or one-curve catheters made of gold, silver, copper, lead or salve of white lead with a rounded end and many side holes and a stylet were the standard instruments.¹² The rubber catheter of Nelaton was invented in 1873. Frederic Eugene Basil Foley was an American urologist who lived from 1891 to 1966. He invented the self-retaining balloon catheter in the 1935.

Acknowledgements EMIS is grateful to the Mentor authoring team for writing this article. The final copy has passed peer review of the independent Mentor GP authoring team. ©EMIS 2006.

Last issued 05 Jul 2006