In this study we aimed to investigate the urinary tract infections (UTI) among spinal cord injured patients who were evaluated by urodynamic studies; also possible correlations between UTI, type of microorganism and gender, type of bladder management and urodynamic findings were examined. Out of 338 patients we could obtain sufficient data in 285. In 172 of the patients urine cultures were positive, E coli being the most predominant microorganism. Indwelling catheterization and UTI were found to be highly correlated.

It was concluded that patients with SCI  should be followed up lifelong for possible urinary tract complications..

Key words: Urinary tract infections, spinal cord injury

Introduction

One of the most common medical complications encountered among spinal cord injury (SCI) patients is urinary tract infections (UTI)(1). Several factors may act  to predispose the patients with neurogenic bladder to UTI.  The most important of these are high pressure voiding, large amounts in postvoiding residuals, bladder catheterization, vesicoureteral reflux, bladder over distention, stones in the urinary tract and outlet obstruction(2,3). In the acute phase of SCI, the indwelling catheterization is switched to the sterile intermittent catheterization providing that the general status of the patient stabilizes and fluid intake and urine volume can be monitorized. Intermittent catheterization is continued throughout the spinal shock period and return of detrussor reflex is mandatory for planning urodynamic studies(4). The most appropriate type of treatment should be considered after the urodynamic studies are completed.

Diseases of the urinary system were reported to be the leading causes of death in previous studies. Based on these reports, research was primarily focused on the treatment of neurogenic bladder and renal complications. Considerable decline in mortality rates were reached due to diseases of the urinary system in the recent decades(5). Despite advances in medical treatment, such as newly developed antibiotics and better catheterization materials, persons with SCI continue to experience problems with UTI(2). Renal infections are usually observed in patients with neurological lesions, particularly when high voiding pressures and/or vesicoureteral reflux are present. Progressive deterioration of renal function in patients with neurogenic bladder can clearly be attributed to the presence of recurrent UTIs(3).

On the other hand, frequent use of antibiotics increases the risk of infection with antibiotic-resistant organisms and complicates the management of UTI(2).

The purpose of this study was to evaluate the characteristics of our spinal cord patients in terms of UTI and to investigate the relationships between type of microorganism (m.o.), demographic characteristics, type of bladder management and urodynamic findings.

Patiens and Methods   

This retrospective study investigated 338 patients with spinal cord injury who were evaluated in our urodynamic labratory between 1997 and 2001. Prior to urodynamic studies, demographic data of the patients, their medical history, urologic symptoms and findings, type of bladder management, urine culture results and type of microorganism if any were recorded. Significant bacteriurea was defined as 105 or more colonies of bacteria forming units per mL of urine. Upper urinary systems of the patients were evaluated further with kidney bladder ultrasonography and blood urea and creatinine levels. Following this procedure, the videourodynamic investigation was performed. In this study we evaluated our results retrospectively and investigated the relation between UTI, clinical and demographic data, type of bladder drainage and detrussor pressures.

Out of 338 patients only 285 data were taken into consideration. The medical data of the other 53 patients were insufficient and were not taken into consideration in the statistical analysis.

Results

In 285 patients urine culture results were obtained (101 female and 184 male). In 218 (76%) of them the culture results were positive. The demographic data, ASIA scores of the patients and type of bladder management were presented  in Table 1 and Table 2.

One hundred seventy seven (62%) of the 285 patients were managed by intermittant catheterization. Due to economic and social problems some of the hospitalized patients could not afford sterile catheterization and were on clean catheterization. Fifty seven (20%) patients were managed by spontaneous trans-urethral voiding, 29 (10.2%) patients with condom catheterization and 22 (7.7%) with indwelling catheterization. Patients with indwelling catheters had the highest ratio of bacteriurea with 95% (Table 2).

When the m.o. were evaluated, E. Coli was the most abundant species (58%). The organisms causing significant bacteriurea are listed in Table 3.

Among 74 female patients E coli was by far the most prevalent organism isolated (73%). Klebsiella, proteus and mixed infections followed in the rest of the population. In males E coli ratio was 50% and enterobacter, proteus and klebsiella were isolated in 11%, 7.6%, 7.6% respectively. Table 4 shows a breakthrough of bacterial isolates according to gender and type of bladder management.

After the urodynamic evaluation the urodynamic diagnosis of the patients were grouped according to detrussor pressure as high pressure and low pressure detrussor. Seventy eight percent of the patients with high pressure and 70% of patients with low pressure detrussor had bacteriurea. The urodynamic diagnosis of the patients are summarized in Table 5.

Discussion

A careful and lifelong follow up is necessary for neurogenic bladder in patients with SCI. Commonly seen urinary tract complications include bladder deformity, vesicoureteric reflux, hydronephrosis and renal failure. UTIs and all other urinary complications are closely related to each other(3).

Bacteriurea, often of low colonies, is extremely common among persons with SCI. Therefore, a threshold of ‘significant bacteriurea’ must be specified in order to interpret experimental findings. A bacterial count of 100,000 or more colonies forming units/ml of urine was chosen as the definition of significant bacteriurea in this study because the value has been widely accepted by clinicians engaged in SCI medicine(6).

The prevalence of significant bacteriurea in our population was 76%. This was the ratio before the urodynamic evaluation so, the high rates may be due to ineffective treatment strategies.

The method of bladder drainage is thought to be a very important risk factor for UTI in SCI patients. Indwelling catheterization with urethteral or suprapubic catheters are the methods most likely to lead to persistent bacteriurea although randomized studies comparing different methods have not been carried out(2). Self intermittent catheterization is one of the best management in the chronic phase of neurogenic bladder due to SCI(3,7).

The bacteriurea ratio in patients using IC was reported to be as 31% to 86% (7-10). The significant bacteriurea ratio in Maynard and Diokno’s study concerning CIC in hospitalized patients is 88%(11). The bacteriurea ratio in our patients with IC were 81%. The high ratio may be related to clean intermittent catheterization management in some of the hospitalized patients due to economic problems. It might be more ideal if we could have performed sterile IC during the hospitalization period.

The UTI ratio in patients with indwelling catheters is 95%. The complication rate in indwelling catheters is quite high. Larsen et al reported complication in 88% of indwelling catheterized patients versus 33% in non catheterized patients(12).

The significant bacteriurea ratio in women is a little bit higher then men (27% vs 36%). There are few studies which have studied the effect of gender as a risk factor for UTIs. In some studies women seem to be more prone to UTIs but these studies are not enough to answer the question and more studies with larger groups should be carried out(13).

In Matsumato’s study, febrile episodes are reported to be more common in the chronic phase of patients. The reasons were thought to be inadequate timing of catheterization, catheterization by untrained patients and family members or intrinsic factors related to host defence(3).

The avearage time from injury in our patients is about 20 months. The long duration can be a contributing factor to the ratio of significant bacteriurea. In Turkey there are no specific centers for SCI and the patients are not always evaluated by experts.

Our study has some limitations. Since it was a retrospective study the clinical symptoms of UTI were not taken into consideration and most of the significant bacteriurea were probably asymptomatic bacteriurea. Prospective stu-dies considering the clinical symptoms of  UTI should be planned. SCI patients should be closely monitored for urinary complications by experts.

Yazışma Adresi:Dr. Berrin Gündüz Korukent Sitesi C Blok Daire 14 Levent 80600 - İSTANBUL Kabul Tarihi: Mart 2003

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