Abstract
Objective:
This study evaluated the influence of different urination methods on the urinary systems of patients with spinal cord injury.
Methods:
Patients with spinal cord injury were grouped according to their usual voiding method: clean intermittent catheterization (CIC); Credé manoeuvre/reflex voiding; indwelling catheterization; normal voiding. Urinary tract infections (UTIs) were monitored and type B-ultra -sonography (B-USG) scans, renal function tests and urodynamic studies were performed in all patients over a 2-year period.
Results:
Compared with the normal voiding group (n = 14), incidence rates of UTIs were significantly different in the Credé manoeuvre/reflex voiding (n = 26) and indwelling catheterization (n = 12) groups but not in the CIC group (n = 15). All intervention groups had a significantly higher rate of positive findings on B-USG scan and a significantly increased residual urine volume, compared with the normal voiding group. In addition, residual urine volume was significantly lower in the CIC group compared with the Credé manoeuvre/reflex voiding and indwelling catheterization groups.
Conclusion:
CIC was shown to be the optimal method for assisted bladder voiding after spinal cord injury.
Keywords
Introduction
Spinal cord injury seriously diminishes a patient's well-being and results in heavy burdens to both family and society. 1 Spinal cord injury not only causes impairment to motor and sensory functions, but also induces neurological bladder dysfunction, resulting in severe urine retention, urinary tract infection (UTI) and chronic renal failure, which is one of the primary causes of death in patients with paraplegia.2–4 Bladder management is, therefore, of great significance for improving health-related quality of life and reducing mortality in patients with spinal cord injury. Nonsurgical interventions for bladder emptying in patients with spinal cord injury include the Credé/Valsalva manoeuvre with reflex voiding, indwelling catheterization, clean intermittent catheterization (CIC) and local or systemic pharmacological therapy. 5
The Credé manoeuvre involves applying suprapubic pressure to induce urination by raising the intravesical pressure to > 50 cm H2O. This manoeuvre may, however, induce complications such as high intravesical pressure, progression of vesicoureteral reflux and nephrohydrosis. In addition, it may increase the possibility of UTIs and urinary lithiasis because of incomplete bladder emptying.6,7 The Credé manoeuvre is used in conjunction with reflex voiding, which is dependent on the presence of an intact sacral micturition reflex. Reflex voiding occurs in patients with spasmodic bladders and results in little residual urine. Such patients often also have detrusor–external sphincter dys-synergia. Reflex voiding may be associated with damage to the upper urinary tract as a result of elevated voiding pressures and symptomatic UTIs because of incomplete bladder emptying.
For indwelling catheterization, a urinary catheter is inserted into the bladder transurethrally or through an abdominal fistula. It is not limited by bladder contraction or coordinated actions of the sphincter mechanism. However, when the bladder is in a long-term nonfilling state, indwelling catheterization may inhibit bladder contraction, resulting in a decrease in bladder capacity and compliance. In addition, long-term indwelling catheterization increases the frequency of UTIs and may be associated with lithiasis. 8
Clean intermittent catheterization, in which bladder voiding via a disposable catheter is implemented at frequent intervals, is recommended as a primary supportive measure in bladder care as it provides complete bladder emptying and offers a practical means of obtaining a catheter-free state. 9
The present study investigated assisted urination methods and analysed their influence on the urinary system in patients with spinal cord injury, in order to gain a better understanding of the effects of different types of voiding function.
Patients and methods
Patients
Patients with spinal cord injury were recruited via the Shanghai Disabled Persons' Federation. The study was carried out at the orthopaedic surgery departments of Shanghai Sixth People's Hospital and Changzheng Hospital, Shanghai, China, between September 2005 and August 2007. Patients with a spinal cord injury who had registered with the Shanghai Disabled Persons' Federation, were 16 years old and who could communicate well were eligible for the study. Exclusion criteria included injury ≤ 1 year ago, cauda equina lesion, comorbid diseases involving cognitive impairment, mechanical ventilation, multiple trauma and head injury. Based on their usual bladder voiding method, patients were divided into four groups: (i) CIC group; (ii) Credé manoeuvre/reflex voiding group; (iii) indwelling catheterization group; (iv) normal voiding group, who served as the controls.
This study was carried out with the approval of the Medical Ethics Committee of Shanghai Sixth People's Hospital, Shanghai Jiaotong University, Shanghai, China (Ref. No. 2012 [L]-6) and was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki. The patients participating in the study provided verbal informed consent. All applicable institutional and governmental regulations concerning the ethical use of human volunteers were followed during the course of this research.
Bladder Voiding Methods
For the CIC group, bladder voiding with a disposable nonballoon catheter (Jiekang Medical Devices, Yangzhou, Jiangsu Province, China) was implemented by the patient or the caregiver every 2 – 4 h. After sterilizing the external orifice of the urethra with the patient in a lateral position, a paraffin wax-lubricated catheter was inserted to drain urine, while avoiding injury to the urethral mucosa, and removed once the bladder had been emptied.
In the Credé manoeuvre/reflex voiding group, a urine drainage bag was connected to the penis or perineum. Using one or both hands, the patient or caregiver applied pressure above the pubic symphysis, squeezing downwards on the bladder, while at the same time simulating the ‘trigger points' in the lower abdomen, perineum or interfemus skin to evoke a micturition reflex. This manoeuvre was continued as necessary until the bladder was completely empty. Voiding was repeated every 2 – 4 h as necessary.
In the indwelling catheterization group, a Foley catheter was inserted into the bladder aseptically and a urine drainage bag attached. The bladder was flushed with 500 ml of normal saline and 160 000 IU gentamycin daily, and the catheter was replaced weekly.
Patient Assessment
All patients were followed up for 2 years. To detect the presence of a UTI, each month clean-catch midstream urine or catheterized urine was collected into an aseptic bottle, from which 0.1 ml was pipetted into 5 ml of enrichment broth (Kexing, Shanghai, China) and incubated at 37°C for 24 h. Next, 100 μl of the broth was inoculated onto a 90-mm China blue lactose agar plate; the same volume of broth was also inoculated onto a 90-mm blood agar plate (Pengli Science and Technology, Beijing, China). The plates were incubated at 37 °C for 24 h for colony counting and strain identification using biochemical reaction strips (NC31 and PC20, Dade Behring, Cupertino, CA, USA). A diagnosis of UTI was made on the basis of a bacterial count ≤ 102 colony-forming units (CFU)/ml in intermittent catheter specimens from four consecutive catheterizations, a bacterial count ≤ 104 CFU/ml in clean-void specimens from catheter-free patients using aseptic bottles, or detection of any bacterial colonies in specimens from indwelling catheters. 10 The presence of separate episodes of UTI was defined as a UTI occurring after two consecutive negative urine cultures after treatment for UTI. The number of UTI episodes over the 2-year study period was recorded for each patient.
Each month B-ultrasonography (B-USG) scanning was undertaken using an ATL HDI 5000® ultrasound system (ATL Philips, Bothwell, WA, USA) with a transducer frequency of 3.5 MHz. A positive B-USG scan was defined as one showing the presence of ureterectasia, nephrohydrosis or urinary tract stones.
Renal function was assessed each month by measuring blood urea nitrogen and serum creatinine in 3-ml venous blood samples using a VITROS® 350 Chemistry System (Johnson & Johnson, New Brunswick, NJ, USA). Renal function impairment was defined as either blood urea nitrogen > 7.2 mmol/l or serum creatinine > 124 μmol/l.
Urodynamic tests, including maximum bladder capacity, maximum detrusor pressure and residual urine volume, were performed each month using a urodynamic detector (Janus V; Life-Tech, Stafford, TX, USA).
Statistical Analyses
Data were presented as means ± SD. The χ2- test was used to determine significant differences between the groups for the incidence rates of UTIs, positive B-USG scan findings and impaired renal function. One-way analysis of variance was used to determine significant differences in the results of urodynamic tests between the groups, and the Student–Newman–Keuls test was used for multiple comparisons. A P-value < 0.05 was considered to be statistically significant. Analyses were performed using STATA software version 10.0 (Stata Corp., College Station, TX, USA).
Results
A total of 67 patients with spinal cord injury were included in the study. Of these, 15 were in the CIC group, 26 were in the Credé manoeuvre/reflex voiding group, 12 were in the indwelling catheterization group and 14 were in the normal voiding group. The patients' demographic and clinical characteristics are shown in Table 1. Levels of incontinence, voiding methods, urodynamic characteristics and bladder function training programmes are given in Table 2.
Characteristics of patients with spinal cord injury, recruited to investigate the influence of different urination methods on the urinary system (n = 67)
Data presented as mean (range) or n (%) of patients.
Level of incontinence, voiding methods, urodynamic characteristics and bladder function training programmes among patients with spinal cord injury, recruited to investigate the influence of different urination methods on the urinary system (n = 67)
UTIs
There was a statistically significant difference in the incidence of UTIs between the Credé manoeuvre/reflex voiding and indwelling catheterization groups compared with the normal voiding group (P < 0.05), whereas there was no significant difference between the CIC group and the normal voiding group (Table 3). In addition, the incidence of no UTIs was significantly lower in the Credé manoeuvre/reflex voiding and indwelling catheterization groups compared with the CIC group (P < 0.05).
Frequency of urinary tract infection, positive B-ultrasonography scan and renal function impairment in patients with spinal cord injury using different urination methods over a 2-year period
Data presented as n (%) of patients.
P < 0.05 versus normal voiding group (χ2-test).
P < 0.05 versus clean intermittent catheterization group (χ2-test).
B-USG Scanning
The numbers of patients in each group with positive B-USG scans are shown in Table 3. Positive scan rates in the CIC, Credé manoeuvre/reflex voiding and indwelling catheterization groups were significantly higher than in the normal voiding group (P < 0.05). The positive scan rate was also significantly higher in the Credé manoeuvre/reflex voiding group than in the CIC group (P < 0.05).
Renal Function
There were no statistically significant differences in the rate of renal function impairment between the four groups (Table 3).
Urodynamic Findings
Results of urodynamic evaluation in the four groups of patients are shown in Table 4. Residual urine volumes in the CIC, Credé manoeuvre/reflex voiding and indwelling catheterization groups were significantly higher than in the normal voiding group (P < 0.05). In addition, residual urine volumes in the Credé manoeuvre/reflex voiding and indwelling catheterization groups were significantly increased compared with the CIC group (P < 0.05).
Urodynamic parameters in patients with spinal cord injury using different urination methods over a 2-year period
Data presented as mean ± SD.
P < 0.05 versus normal voiding group (Student–Newman–Keuls test).
P < 0.05 versus clean intermittent catheterization group (Student–Newman–Keuls test).
Maximum detrusor pressures in the CIC and indwelling catheterization groups were significantly lower than in the normal voiding group (P < 0.05); this was because most patients in the CIC and indwelling catheterization groups had atonic bladders. Maximum detrusor pressure in the Credé manoeuvre/reflex voiding group was significantly increased compared with the normal voiding group (P < 0.05), reflecting the number of patients with spasmodic bladders in the Credé manoeuvre/reflex voiding group. In addition, the maximum detrusor pressure in the Credé manoeuvre/reflex voiding group was significantly higher than in the CIC group (P < 0.05). There were no statistically significant differences in maximum bladder capacity between the four groups.
Discussion
The present study demonstrated that, compared with the Credé manoeuvre/reflex voiding and indwelling catheterization, CIC promoted bladder function by dilating the bladder periodically and maintaining bladder emptying. Furthermore, compared with the Credé manoeuvre/reflex voiding and indwelling catheterization, residual urine volume was significantly lower. CIC also significantly reduced the occurrence of UTIs compared with the Credé manoeuvre/reflex voiding and indwelling catheterization, and attenuated impairment to the upper urinary tract (such as ureterectasia, nephrohydrosis and urinary tract stones) compared with the Credé manoeuvre/reflex voiding.
Patients with spinal cord injury manifest with varying degrees of bladder dysfunction, because damage to the spinal cord affects the innervation of the bladder and urethra, resulting in functional impairment of urine storage and/or voiding of the bladder. A recent survey indicated that patients with neurogenic bladder may receive suboptimal management, indicated by a high incidence of urinary tract complications and hospitalizations. 11 As bladder dysfunction may induce severe urinary incontinence or retention, UTIs, vesicoureteral reflux and even chronic renal failure (which may result in death), treatment and improvement of spinal cord injury-induced bladder dysfunction is of great clinical significance. 4 In the present study, 53 out of 67 patients with postspinal cord injury bladder dysfunction required intervention for voiding using the Credé manoeuvre/reflex voiding, indwelling catheterization or CIC. Of these, only 15 patients used CIC to void urine, whereas the majority (38 patients) used either the Credé manoeuvre/reflex voiding or indwelling catheterization.
Since Lapides et al. 12 first put forward the idea of CIC in 1971, it has become the ‘gold standard' method for bladder emptying in all neuropathic patients with neurogenic lower urinary tract dysfunction. The technique is safe and effective, and results in improved kidney and upper urinary tract status, lessening of vesicoureteral reflux and amelioration of urinary continence. 9 In the present study, only 15 patients used CIC out of the 53 who used some form of urination method. The reasons for this may include the relatively expensive cost and time-consuming nature of CIC. CIC facilitates the recovery of bladder function because it enables the bladder to dilate and empty periodically (thus maintaining the bladder in an almost normal physiological state), and effectively decreases residual urine in the bladder and the incidence of UTIs. 13 The earlier that CIC is implemented after spinal cord injury, the more beneficial it is to the restoration of bladder function and the prevention of complications without the need for prophylactic antibiotics to prevent UTIs.14,15 The present study showed that there was no significant difference in UTI occurrence between the CIC group and the normal voiding group; this is consistent with the findings of Seki et al. 16 In contrast, use of the Credé manoeuvre/reflex voiding or indwelling catheterization may increase the incidence of UTIs. Similar to the present study, a recent prospective investigation by Singh et al. 17 demonstrated that the incidence of UTIs is lower in patients with CIC compared with patients with indwelling catheterization. Of 74 patients using the Credé manoeuvre over extended periods of time, Chang et al. 7 reported pyuria in 82.4%, urinary lithiasis in 31.3%, ureteral dilatation in 59.5%, nephrohydrosis in 35.1% and renal damage in 16.2% of cases. This suggests that the Credé manoeuvre may not offer good safety or efficacy profiles for patients with spinal cord injury. In addition, urodynamic data in the present study showed that the volume of residual urine was significantly higher in the Credé manoeuvre/reflex voiding and indwelling catheterization groups than in the CIC group, increasing the risk of UTIs.
The B-USG scan findings showed that the presence of ureterectasia, nephrohydrosis or urinary tract stones was significantly higher in the Credé manoeuvre/reflex voiding group compared with the CIC group. This is probably because the Credé manoeuvre increases intravesical pressure, thus promoting vesicoureteral reflux and aggravating nephrohydrosis in the upper urinary tract. In addition, incomplete bladder emptying may lead to UTI and urinary lithiasis.
Overall, CIC can decrease the occurrence of UTIs and reduce damage to the upper urinary tract compared with the Credé manoeuvre/reflex voiding and indwelling catheterization and, therefore, should be the treatment of choice for assisted urination in patients with spinal cord injury. However, CIC does affect patients' health-related quality of life, it may be complicated by genitourinary tract infections and it may be accompanied by anxiety about urine leakage. In a health-related quality of life survey using the Medical Outcomes Study 36-Item Short-Form General Health Survey (SF-36) in 132 patients with spinal cord injury who were on CIC, Oh et al. 18 found that, compared with the general population, patients' quality of life was significantly lower in all the SF-36 health domains. In a retrospective study of 140 male patients with spinal cord injury who used CIC or indwelling catheterization, Ku et al. 19 found that the incidence of epididymo-orchitis was significantly higher in patients who used CIC compared with those who used indwelling urethral catheterization (42.2% versus 8.3%). Additionally, Liu et al. 20 found that CIC performed by an attendant was related to the worst mental status in patients with spinal cord injury compared with other bladder management methods including normal voiding, reflex voiding and bladder expression.
The use of simple, reliable and effective techniques to assess postspinal cord injury effects on the urinary system is of great significance in improving patients' health-related quality of life. In the present study, B-USG scanning, renal function evaluation and urodynamic studies were used to observe the influences of different methods of assisted urination on the urinary system of patients with spinal cord injury. B-USG studies can determine the presence of morphological changes such as ureterectasia, nephrohydrosis and urinary tract stones, whereas renal function evaluation and urodynamic studies can determine functional impairments. In the present study there was no significant difference in renal function impairment between the groups; this may be because blood urea nitrogen and serum creatinine levels are not sensitive indices for detecting early impairment to the urinary system, and would only detect more severe conditions such as chronic renal failure. Urodynamic studies demonstrated that the maximum detrusor pressures in the CIC and indwelling catheterization groups were significantly lower than in the normal voiding group, which is consistent with the likely presence of atonic bladders in the former two groups. The maximum detrusor pressure in the Credé manoeuvre/reflex voiding group was significantly higher than in the normal voiding group, which is consistent with the likely presence of spasmodic bladders in the former group. Maximum detrusor pressure therefore appeared to be related to the nature of the bladder dysfunction rather than impairment of the urinary system. Residual urine levels in patients in the CIC, Credé manoeuvre/reflex voiding and indwelling catheterization groups were significantly increased compared with those in the normal voiding group; this was associated with an increase in morphological abnormalities in all three groups and an increase in UTIs in the Credé manoeuvre/reflex voiding and indwelling catheterization groups, compared with the normal voiding group. A study by Choe et al. 21 showed that residual urine can be measured effectively using B-USG scanning. B-USG scanning is, therefore, a simple and effective strategy to monitor residual urine and impairment to the upper urinary tract after spinal cord injury.
The present study had a number of limitations. First, the study was not a randomized clinical study and, because of the obvious nature of the intervention, no bladder management regimens were double-blind. A future prospective randomized study, comparing different urination methods in patients with spinal cord injury, would enable better assessment of the effectiveness of nonsurgical interventions for bladder emptying. Secondly, when considering the statistical power of the analysis, the study population was too small to examine gender differences. Thirdly, the present study did not carry out a health-related quality-of-life evaluation.
In summary, CIC was shown to be the optimal method for assisted bladder voiding after spinal cord injury. In addition, B-USG scanning was shown to be a simple and effective strategy to monitor residual urine and to observe postspinal cord injury impairment to the urinary system. Future research should include a larger multicentre randomized study that could provide more robust evidence.
Footnotes
Acknowledgement
This work was supported by the fund of the National Natural Science Foundation of China (30901507).
The authors had no conflicts of interest to declare in relation to this article.