VOL: 101, ISSUE: 47, PAGE NO: 63
Linda Nazarko, MSc, RN, FRCN, is consultant nurse - older people, Richmond and Twickenham Primary Care Trust, and visiting lecturer, South Bank University, LondonSome years ago, Mrs Dorothy Evans, who has insulin-dependent diabetes, went to see her GP because she had urinary frequency and urgency. She was prescribed three courses of antibiotics, but her problems persisted. Her GP then prescribed an anticholinergic drug - used to treat detrusor (bladder muscle) hyperreflexia (unstable bladder) - but this provided Mrs Evans with little relief, so that over the next few years her life was dominated by her bladder. Mrs Evans now had to time her shopping trips to coincide with her bladder symptoms, and knew the location of all the local public toilets. She also experienced urinary tract infections each year, which were treated with antibiotics.
Some years ago, Mrs Dorothy Evans, who has insulin-dependent diabetes, went to see her GP because she had urinary frequency and urgency. She was prescribed three courses of antibiotics, but her problems persisted. Her GP then prescribed an anticholinergic drug - used to treat detrusor (bladder muscle) hyperreflexia (unstable bladder) - but this provided Mrs Evans with little relief, so that over the next few years her life was dominated by her bladder. Mrs Evans now had to time her shopping trips to coincide with her bladder symptoms, and knew the location of all the local public toilets. She also experienced urinary tract infections each year, which were treated with antibiotics.
Just before her 70th birthday Mrs Evans became acutely unwell and was admitted to hospital from the A&E department with a urinary tract infection. Her bladder was palpable but she was able to pass only small amounts of urine. A bladder scan showed that Mrs Evans had a residual volume of urine in her bladder of 450ml.
Following a detailed history, it was revealed that Mrs Evans had been experiencing urinary problems for almost five years. She felt that these were just 'part of getting older', but then confessed that they were making her miserable.
What went wrong with Mrs Evans' management?
Urinary tract infections are normally treated in general practice. Fourteen per cent of patients require a second course of antibiotic therapy within 28 days. This is more common in older people (Prodigy, 2004).
In the case of Mrs Evans, three courses of antibiotics had failed to eradicate her urinary tract infection, which suggests that there could be underlying problems in the urinary tract. She should therefore have been referred for further investigations (Prodigy, 2004; Cattell, 1997; Stamm and Hooton, 1993).
Women are more at risk of developing urinary tract infections than men because of anatomical differences in the structure and position of the urethra. Furthermore, older people are more likely than young people to develop such infections because of age-related changes to the urinary system (Nazarko, 2005), and women with diabetes are twice as likely to develop urinary tract infections than women without diabetes (Boyko et al, 2005).
How diabetes affects bladder function
People with diabetes are more likely to have bladder problems than the general population (Johansson et al, 1996). This is because diabetes can lead to nerve damage (neuropathy), which can affect nerves throughout the body. It is not yet understood why people with diabetes develop neuropathy, but there is evidence that poor glycaemic control and vascular damage contribute to its development (Watkins and Edmonds, 1997). Neuropathy that affects nerves in the autonomic nervous system (autonomic neuropathy) is a serious and common complication of diabetes (Vinik et al, 2003).
Autonomic neuropathy can affect bladder function, because if the stretch receptors in the bladder are unable to detect when the bladder is full, the sensation of fullness is not conveyed to the brain. The sacral nerves that convey messages from the bladder can also be affected by neuropathy. These changes in the autonomic nervous system can cause two bladder problems: hypotonic bladder and, less commonly, detrusor instability.
A hypotonic bladder occurs when there is damage to the stretch receptors in the bladder, which reduces awareness of its being full. This means that the bladder may become over-full, in which case it stretches. The result is that a patient may build up a residual volume of urine in the bladder of 500-2,000ml (Mundy and Blaivas, 1985). The consequences of this stretching of the bladder wall are that the detrusor muscle contractions become weak and ineffective, which can then lead to urinary frequency or overflow incontinence.
A hypotonic bladder and overflow incontinence are uncommon in women and may therefore be overlooked as a cause of incontinence unless a comprehensive bladder assessment is carried out. If this is not done, frequency can be misdiagnosed as detrusor hyperreflexia, and urinary leakage may be misdiagnosed as stress incontinence.
It is important to treat the problem of a hypotonic bladder because when the bladder becomes full, urine cannot drain from the kidneys, and back pressure of urine can cause renal damage.
Mrs Evans' diagnosis
A full continence assessment revealed that Mrs Evans' real problem was her inability to empty her bladder properly because she had a hypotonic bladder. This was why the anticholingeric drugs that she had been prescribed were not solving her problem.
Anticholinergic drugs, such as oxybutynin and tolterodine, are used to treat detrusor hyperreflexia. Normally the bladder does not contract while filling, but patients with detrusor hyperreflexia suffer from uncontrolled bladder contractions. This means that although the bladder might have a capacity of 500ml, bladder contractions can start to occur at 250ml and the working capacity of the bladder is reduced.
Anticholinergic drugs act by reducing these bladder contractions and improving bladder capacity (Malone-Lee et al, 1992; Wein, 1990). There are a number of causes of detrusor hyperreflexia; these include, high caffeine intake, side-effects of medication and constipation. The problem may resolve, however, if these factors are dealt with.
Anticholinergic drugs should not be prescribed unless a patient has had a comprehensive bladder assessment and does not respond to non-pharmacological interventions (Nazarko, 1996). Unfortunately Mrs Evans did not have a comprehensive assessment before she was prescribed the anticholinergic drugs.
Assessment and treatment of hypotonic bladder
The reasons for treating a hypotonic bladder are outlined in Box 1. Following the assessment, which revealed that Mrs Evans had a hypotonic bladder, the anticholinergic medication was discontinued. She was not taking any other medication that could have caused problems with bladder emptying, and was not constipated. Furthermore, she was reasonably mobile.
A fluid intake and output chart was started, which showed that Mrs Evans was passing around 100ml of urine every hour. Her renal function was normal for her age.
A variety of treatment options was used without success. These included:
- Massaging and tapping the bladder;
- Using a battery-powered bladder stimulator;
- Applying a warm flannel to the abdomen;
- Applying ice cubes wrapped in a cloth.
We now had two remaining alternatives. Mrs Evans could have either a permanent indwelling catheter inserted or she could have intermittent catheterisation.
The benefit of an indwelling catheter is that it is less difficult to manage than an intermittent one, and is therefore suitable for those who are frail and whose manual dexterity is poor. However, there are risks associated with indwelling catheters, including infection, blockage, encrustation, tissue damage, and leakage. Bladder capacity can also be reduced, although this problem can be solved by using a catheter valve (Addison, 1999).
The benefit of intermittent catheterisation is that the risk of infection is reduced, as are the other potential complications of an indwelling catheter. However, the patient needs to be physically and mentally able to carry out the procedure.
Both options were discussed with Mrs Evans. She was keen to try intermittent catheterisation but was worried that she would be unable to develop the skills to carry it out.
Mrs Evans, like many women of her generation, was unfamiliar with the position of her urethra. However, after using a model to show her its position and to demonstrate how to perform intermittent catheterisation, an intermittent catheter was used to drain the urine from her bladder. She watched in a mirror to see how the process was carried out.
Mrs Evans soon became skilled in passing the catheter, and found that her residual urine built up slowly so that she needed to use the catheter only once a day. The volume of urine passed by her urethra increased to 200-250ml, which meant that she had to pass urine every two or three hours.
Appropriate assessment and treatment made a real difference to Mrs Evans' life. She could now go to the hairdresser, and shop and socialise with friends without worrying about her bladder. Our challenge as professionals is to ensure that older people benefit from appropriate assessment and treatment so that they can have the best possible quality of life.