Washout policies for management of long‐term voiding problems in catheterised adults
Abstract
This is a protocol for a Cochrane Review (Intervention). The objectives are as follows:
To determine the effects of different types of washout policies in adults requiring urinary catheterisation for long‐term voiding problems.
The following hypotheses will be tested: ‐
1. Water washouts are better than no washouts.
2. Saline washouts are better than no washouts.
3. Antifungal washouts are better than no washouts.
4. Antibiotic washouts are better than no washouts.
5. Antiseptic washouts are better than no washouts.
6. Any of the above interventions are better than one or more of the other interventions.
7. Long intervals between washouts are better than short intervals
Background
Patients may require long‐term urinary catheterisation for a number of reasons. These include urinary retention, caused by prostatic hypertrophy for example, or urinary incontinence. Incontinence may be a problem for those suffering from dementia, stroke, spina bifida, spinal compression, or paraplegia. It may also affect those who have undergone pelvic surgery or radiotherapy, e.g. for prostate cancer. There have been recent reviews of the management of urinary catheters (Cravens 2000; Evans 2000; Parker 1999). Between 10% and 12% of hospitalised patients and 4% of patients in the community have been estimated to require indwelling catheterisation (Crow 1988).
Urinary tract infection is the major problem associated with catheterisation. Significant levels of bladder bacteriuria are found in hospital patients within seventy‐two hours (Crow 1988). Guidelines have recently been published for preventing infections associated with the use of short‐term indwelling urethral catheters in acute care (Pratt 2001). Infection control can also be difficult in long‐term catheter maintenance, and irrigation or washout was introduced in an attempt to deal with this problem.
Up to 50% of long‐term catheterised patients suffer recurrent catheter blockage (Getliffe 1994), the most common cause of which is the encrustation of the surface of the catheter with deposits of mineral salts from urine (Getliffe 1996). Reducing such encrustations may be another reason for performing catheter washout. The distress caused to patients by acute catheter blockage has been highlighted as has the avoidable demands on accident and emergency departments by blocked catheters in patients in the community (Evans 2000). The role of planned catheter change and washout in avoiding these problems was also emphasised (Evans 2000).
Encrustation and infection can also be related. Proteus mirabilis produces a urease that splits ammonia causing alkaline urine and precipitation of struvite and apatite crystals (Warren 1997). A number of antiseptic solutions have been shown to be effective in washout procedures using models of the catheterised bladder. However, only mandelic acid was able to deal with heavy contamination (King 1991). The value of antifungal washouts has also been demonstrated (Fong 1995).
The wide variety of washout solutions available, combined with the multiplicity of possible procedures for applying these, indicate that a systematic review of these policies is necessary to highlight gaps in the evidence base and assist in the identification of best practice.
Objectives
To determine the effects of different types of washout policies in adults requiring urinary catheterisation for long‐term voiding problems.
The following hypotheses will be tested: ‐
1. Water washouts are better than no washouts.
2. Saline washouts are better than no washouts.
3. Antifungal washouts are better than no washouts.
4. Antibiotic washouts are better than no washouts.
5. Antiseptic washouts are better than no washouts.
6. Any of the above interventions are better than one or more of the other interventions.
7. Long intervals between washouts are better than short intervals
Methods of the review
Selection of trials:
Randomised trials and quasi‐randomised trials will be identified using the above search strategy. Studies will be excluded if they are not randomised or quasi‐randomised trials for adults with long‐term indwelling urinary catheters. Excluded studies will be listed with reasons for their exclusion.
Quality of trials:
All possibly eligible studies will be evaluated for methodological quality and appropriateness for inclusion by two reviewers without prior consideration of the results. Assessment of methodological quality will be undertaken by each reviewer using the Incontinence Group's assessment criteria which include quality of random allocation and concealment, description of dropouts and withdrawals, analysis by intention to treat, and 'blinding' during treatment and at outcome assessment. It is possible that in some studies confounding variables may have been introduced after randomisation (e.g. the initiation of treatment with systemic antibiotics). Studies will be assessed as to whether such significant confounding variables are introduced and will be excluded if present. Any differences of opinion will be resolved by discussion with the third reviewer.
Data extraction:
This will be performed independently on included studies by two of the reviewers and cross‐checked. Where data may have been collected but not reported, clarification will be sought from the authors. Included trial data will be processed as described in the Cochrane Collaboration Handbook (Clarke 2001).
Statistical analyses:
When appropriate, meta‐analysis will be undertaken. For categorical outcomes we will relate the numbers reporting an outcome to the numbers at risk in each group to derive a relative risk (RR). For continuous variables we will use means and standard deviations to derive a weighted mean difference (WMD). A fixed effect model will be used for calculations of pooled estimates and their 95% confidence intervals. Differences between trials will be further investigated if statistically significant heterogeneity is found at the 10% level or appears obvious from visual inspection of the results. Sensitivity analysis for individual methodological criteria will be carried out if possible. Sub‐group analyses may also be undertaken if the data allow (e.g. male/female patients, urethral/suprapubic catheters).
