For people who use a catheter, whether for a short time or long-term, catheter-associated urinary tract infections (CAUTIs) are a real risk. There can be many different reasons for needing to catheterise, and also different types of catheters. But, with any kind of catheterisation, there is the risk of introducing bacteria into the urinary tract, which can cause infection.
Here are some important statistics around catheterisation and UTI:
- Up to 36% of healthcare-associated infections are UTIs - CAUTIs account for up to 80% of these, a remarkable statistic.
- With a catheter that is left in place, the daily risk of finding a significant amount of bacteria in the urine is around 3-7%.
- Women are more at risk from catheter-associated UTI than men, as with uncomplicated UTI.
Indwelling or intermittent catheterisation?
The two main types of catheterisation are indwelling and intermittent.
Intermittent catheters are only inserted long enough to empty the bladder. They’re normally used once and then thrown away.
Indwelling catheters are left inserted, and are drained periodically. They are changed periodically, up to every 12 weeks.
70-80% of CAUTIs are linked to indwelling catheterisation. The longer a catheter stays in the body, the greater the risk of developing an infection. So healthcare professionals will suggest intermittent catheterisation whenever possible.
Why do people need to catheterise?
There are a number of different reasons.
Catheterisation is very prevalent in hospital patients. Around 15-20% of hospital inpatients are catheterised.
One study found some of the most common reasons for catheterisation in hospital patients to be:
- Urinary retention (being unable to fully empty the bladder e.g. due to a blockage, or bladder weakness)
- Having limited mobility following injury / stroke
- Following urological surgery
The NHS also lists the following as common reasons for needing to catheterise:
- During childbirth with an epidural anaesthetic
- For draining the bladder before, during, or after surgery
- To deliver medicine directly into the bladder (e.g. chemotherapy for bladder cancer)
- Treatment for urinary incontinence
How an infection develops
It is possible for different species of bacteria to form colonies and stick to a catheter (on the inside or outside).
The presence of a catheter actually induces an immune response in the body, but this response creates a better environment for bacteria to thrive in!
The immune response to the presence of a catheter results in the production of something called fibrinogen - a protein. And bacteria can attach themselves easily to a fibrinogen-coated catheter.
If you are curious about the microbiology behind CAUTI and want to know more, check out this research article, which explains the stages of infection.
It is important with catheter use that the catheter is inserted correctly, maintained properly, and is only in use for as long as necessary.
The NHS recommends:
- Daily washing of the area where the catheter enters the body.
- Hand-washing before and after handling any catheter equipment.
- Keeping hydrated
- Avoiding constipation by eating plenty of high-fibre foods
- Making sure the catheter is kept straight
Patients who are using a catheter are also advised to frequently check with their doctor about whether their catheter is still needed.
Testing and treatment for CAUTI
If you develop symptoms of a CAUTI, it is most likely that you will provide a urine sample that will be sent off to be cultured.
If the culture returns a positive result, the recommended treatment would likely be a 7-day course of antibiotics.
The National Institute for Health and Care Excellence (NICE) advises removal of the catheter and initiation of antibiotic treatment as soon as possible.