Catheterisation

Before performing a catheterisation, the doctor should understand the aim behind the procedure. The indications of catheterisation can be classified into short-term and long-term indications.

Short term indications are the following:

• Patients with acute urinary retention (inability to completely empty the bladder)
• Emptying of the urinary bladder before surgery, including urological or pelvic surgery such as a removal of the uterus (hysterectomy)
• For calculating the urinary output in patients who are critical

The long-term indications for catheterisation include the following:

• Patients with chronic urinary retention due to obstruction at the outlet of the bladder that cannot be treated by other means
• Patients with urinary incontinence (uncontrolled leakage of urine) in patients who are terminally ill or extremely frail and repeatedly wet the bed or when incontinence leads to local destruction of skin tissue

The kind of catheter depends on a lot of factors including the indication, the duration it is required for, the risk of infection and the patient’s choice.

They include the following:

• External versus indwelling catheters: Condom catheters can be used in men with urinary incontinence and no urinary retention along with impaired function. They have the advantage of lower risk of infection and are more comfortable as compared to indwelling catheters but carry the disadvantages of having the risk of skin destruction and reduction in blood supply to the penis. Some patients may also have leakage from external catheters.
• Intermittent catheterisation: This is used over long-term indwelling catheters in patients with a neuropathic bladder (disruption in the nervous supply of the bladder that leads to urinary retention). They’re commonly used in patients with spinal cord injuries. The advantage is that they carry a lower risk of urinary tract infection. The disadvantage is a higher risk of skin infections (cellulitis).

Catheters come in numerous sizes and can be made of different kinds of materials which include the following:

• Latex
• Silicone
• Teflon

The types of catheters include the following:

• Foley catheter (most commonly used)
• Straight catheter
• Coude tip catheter
• Silver catheters which have antimicrobial properties

Self-retaining foley catheters are the most commonly used ones and are basically soft rubber tubes inserted inside the urinary bladder. They are held in place using a balloon at the end of the tube that is inflated using normal saline. Previously, foley catheters were made of latex but now silicone-based catheters are preferred as it helps in preventing skin irritation caused by latex. They are also more rigid and have a longer life, lasting up to two months. It is important to not leave the catheter inside beyond the recommended duration of time.

The most common drainage system is the urinary drainage bag that is usually attached to the leg of the patients and can collect up to 750ml of urine. These bags usually hang with the help of a hanger on the side of the bed. It is essential that a closed drainage system be used (connecting the catheter to the drainage bag in a closed continuous unit) as it can help in decreasing the risk of a urinary tract infection.

Catheters should be inserted via an aseptic ‘no-touch’ technique as it helps in reducing the risk of infections. Only the plastic packing can be touched and not the catheter inside it.

The following equipment is required to perform a successful insertion of catheter:

• Sterile gloves
• Antiseptic solution
• Swabs
• Antiseptic anesthetic gel
• Range of urinary catheters
• Urine bag with tube
• Syringe with normal saline to inflate the balloon of the foley catheter

There are numerous issues that can occur due to problems with catheter management. These may include the following:

• Leakage: Try using a smaller catheter size. Do exclude conditions like constipation and catheter blocks.
• Crust formation: it can occur due to the accumulation of various minerals and other materials like proteins or bacteria. It results in recurrent blocks. It is advisable to increase fluid intake and to consume acidifying substances like vitamin C and cranberry juice.
• Inflammation and irritation: This depends on the catheter material used. In this case, a different catheter type is to be used.
• Blockage of urinary catheter: This requires a change of catheter. Try changing catheters regularly as there may be a blockage each time by the end of the life of the catheter.

The following should be kept in mind while removing a catheter:

• Previously, catheters were removed early in the morning, so that if the patient is unable to pass urine afterwards, it is noted easily and followed by re-catheterisation. Some doctors recommend removing it at night just before going to sleep as normally people empty their bladder before going to bed; if the patient is unable to pass urine in the morning, the catheter is inserted again. A proper time must be selected and one should avoid disrupting the patient’s sleep.
• When it’s time to remove the urinary catheter, a syringe can be attached to the opening connected to the balloon and the normal saline inside the balloon removed. The catheter can then be slowly pulled out.
• In case the balloon cannot be completely emptied, try being extremely soft and slow with the traction on the plunger of the syringe. You may also need to inject 1-2 ml of water to remove any adhesions. You can try rotating the catheter while pulling on the plunger. The catheter may also be cut just outside the urethra. Make sure that it does not go back inside the bladder. You can put a safety pin to prevent this - leave the catheter for an hour or two and allow the balloon to empty completely.
• If the balloon still remains rigid, you can locate and puncture it by a digital examination, using a small needle. This is usually done through the rectum in males and the vagina in females.
• In case a doctor over-inflates the balloon and bursts it, a cystoscopy (visualising the bladder with a camera) followed by removal of any remaining pieces is required.

The complications of catheterisation can be traumatic or infective.

Traumatic complications may include the following: 

• Bleeding
• Urethral perforation
• Urethral strictures (restrictions)
• Creation of false passages

Infective complications include the following:

• Cystitis (infection of the urinary bladder)
• Urethritis (infection of the urethra)
• Prostatitis (infection of the prostate)
• Pyelonephritis (infection of kidneys)
• Abdominal wall infections
• Sepsis (when bacteria enters the blood)