Pharmacodynamics and effectiveness of topical nitroglycerin at lowering blood pressure during autonomic dysreflexia.

STUDY DESIGN: Secondary analysis of prospectively collected observational data assessing the safety of an autonomic dysreflexia (AD) management protocol. OBJECTIVES: To estimate the time to onset of action, time to full clinical effect (sustained systolic blood pressure (SBP) <160 mm Hg) and effectiveness of nitroglycerin ointment at lowering blood pressure for patients with spinal cord injuries experiencing AD. SETTING: US Veterans Affairs inpatient spinal cord injury (SCI) unit. METHODS: Episodes of AD recalcitrant to nonpharmacologic interventions that were given one to two inches of 2% topical nitroglycerin ointment were recorded. Pharmacodynamics as above and predictive characteristics (through a mixed multivariate logistic regression model) were calculated. RESULTS: A total of 260 episodes of pharmacologically managed AD were recorded in 56 individuals. Time to onset of action for nitroglycerin ointment was 9-11 min. Time to full clinical effect was 14-20 min. Topical nitroglycerin controlled SBP <160 mm Hg in 77.3% of pharmacologically treated AD episodes with the remainder requiring additional antihypertensive medications. A multivariate logistic regression model was unable to identify statistically significant factors to predict which patients would respond to nitroglycerin ointment (odds ratios 95% confidence intervals 0.29-4.93). The adverse event rate, entirely attributed to hypotension, was 3.6% with seven of the eight events resolving with close observation alone and one episode requiring normal saline. CONCLUSIONS: Nitroglycerin ointment has a rapid onset of action and time to full clinical effect with high efficacy and relatively low adverse event rate for patients with SCI experiencing AD.

International Spinal Cord Injury Urinary Tract Infection Basic Data Set.

OBJECTIVES: To develop an International Spinal Cord Injury (SCI) Urinary Tract Infection (UTI) Basic Data Set presenting a standardized format for the collection and reporting of a minimal amount of information on UTIs in daily practice or research. SETTING: International working group. METHODS: The draft of the Data Set developed by a working group was reviewed by the Executive Committee of the International SCI Standards and Data Sets, and later by the International Spinal Cord Society (ISCoS) Scientific Committee and the American Spinal Injury Association (ASIA) Board. Relevant and interested scientific and professional (international) organizations and societies (∼40) were also invited to review the data set, and it was posted on the ISCoS and ASIA websites for 3 months to allow comments and suggestions. The ISCoS Scientific Committee, Executive Committee and ASIA Board received the data set for final review and approval. RESULTS: The International SCI UTI Basic Data Set includes the following variables: date of data collection, length of time of sign(s)/symptom(s), results of urine dipstick test for nitrite and leukocyte esterase, urine culture results and resistance pattern. The complete instructions for data collection and the data form itself are freely available on the website of ISCoS (http://www.iscos.org.uk).

International standards to document remaining autonomic function after spinal cord injury.

STUDY DESIGN: Experts opinions consensus. OBJECTIVE: To develop a common strategy to document remaining autonomic neurologic function following spinal cord injury (SCI). BACKGROUND AND RATIONALE: The impact of a specific SCI on a person's neurologic function is generally described through use of the International Standards for the Neurological Classification of SCI. These standards document the remaining motor and sensory function that a person may have; however, they do not provide information about the status of a person's autonomic function. METHODS: Based on this deficiency, the American Spinal Injury Association (ASIA) and the International Spinal Cord Society (ISCoS) commissioned a group of international experts to develop a common strategy to document the remaining autonomic neurologic function. RESULTS: Four subgroups were commissioned: bladder, bowel, sexual function and general autonomic function. On-line communication was followed by numerous face to face meetings. The information was then presented in a summary format at a course on Measurement in Spinal Cord Injury, held on June 24, 2006. Subsequent to this it was revised online by the committee members, posted on the websites of both ASIA and ISCoS for comment and re-revised through webcasts. Topics include an overview of autonomic anatomy, classification of cardiovascular, respiratory, sudomotor and thermoregulatory function, bladder, bowel and sexual function. CONCLUSION: This document describes a new system to document the impact of SCI on autonomic function. Based upon current knowledge of the neuroanatomy of autonomic function this paper provides a framework with which to communicate the effects of specific spinal cord injuries on cardiovascular, broncho-pulmonary, sudomotor, bladder, bowel and sexual function.

Research priorities for urological care following spinal cord injury: recommendations of an expert panel.

OBJECTIVE: A multidisciplinary panel of experts from Canada and the United States was convened by the Ontario Neurotrauma Foundation (ONF) to establish research priorities in the area of urological care following spinal cord injury (SCI). DESIGN: The panel reviewed a synthesis of published literature in five areas of urology, identified emerging opportunities in the private and public sector, and used a modified Delphi approach to reach consensus on priorities for funding. RESULTS: The panel recommendations included: clinical trials of the safety and efficacy of M3 receptor specific anti-muscarinic agents for bladder hyperactivity in SCI patients; development and testing of protocols for sacral nerve electrostimulation without sacral afferent neurectomy for management of micturition - including selective stimulation of sacral nerve fibers, high frequency blocking of the pudendal nerve to minimize the risk of urethral sphincter co-contraction and genital nerve stimulation for bladder inhibition and incontinence management; clinical trials of the efficacy and safety of intra-urethral valve catheters; trials of the efficacy of probiotics for bacterial interference i.e. to reduce colonization by uropathogens and manage the dual problems of infection and pathogen resistance to anti-microbials: innovations in the prevention or treatment of stone disease (ureteral, bladder and kidney). CONCLUSIONS: The recommendations form the strategic priorities of the ONF SCI grants program for Ontario-based investigators and their partnerships with out-of-province collaborators and organizations.

Effects of the routine change of chronic indwelling Foley catheters in persons with spinal cord injury.

OBJECTIVE: To determine whether routine catheter changes have any effect on the urinary white blood cell count (WBC) and bacterial culture in asymptomatic individuals with spinal cord injury (SCI) who have indwelling Foley catheters. DESIGN: Prospective case series. SETTING: Urology and SCI outpatient departments of a rehabilitation center. SUBJECTS: Twelve asymptomatic individuals (male and female) with SCI who have chronic indwelling urethral Foley catheters that are changed routinely every month. MAIN OUTCOME MEASURES: Two sets of urinalysis and urinary culture and sensitivity from each individual, one set taken through the Foley catheter before the catheter change and another set after the catheter change. WBC, bacterial identity, and colony count were measured, and the corresponding data were compared. RESULTS: All subjects had pyuria and bacteriuria before and after the catheter change. Analysis of the data showed a statistically significant increase in WBC in the urine after the indwelling Foley catheter was changed (P = .0039). However, bacterial types and corresponding colony counts remained almost completely unchanged. CONCLUSIONS: Routine change of chronic indwelling Foley catheters in asymptomatic individuals with SCI causes a significant rise in the urinary WBC, without altering the bacterial identity or colony count. Pyuria and bacteriuria are prevalent among individuals with SCI (including those who are asymptomatic) with indwelling Foley catheters. This study suggests that urinalysis should be taken before a catheter change.

A method to minimize indwelling catheter calcification and bladder stones in individuals with spinal cord injury.

Indwelling catheters are a common tool of bladder management in persons with high-level spinal cord injury who are unable to intermittently catheterize their bladders. Indwelling catheters are used to prevent bladder overdistension, which can trigger autonomic dysreflexia in those with injuries at or above T6. Unfortunately, indwelling catheters are prone to encrustation and can lead to the formation of bladder stones that can block the catheter and cause autonomic dysreflexia. We found that weekly catheter changes dramatically reduced catheter encrustation and stones in 2 individuals who had a history of recurrent stones despite various accepted interventions. We describe the clinical course and impact of this method in each case.

Autonomic dysreflexia and foot and ankle surgery.

Autonomic dysreflexia is a syndrome of massive imbalance of reflex sympathetic discharge occurring in patients with spinal cord injury with a lesion above the splanchnic outflow (Thoracic 6). Autonomic dysreflexia is characterized by a sudden and severe rise in blood pressure and is potentially life threatening. Because the onset of this entity is rapid and the potential morbidity is severe, it is important for those caring for spinal cord injury patients to be aware of this syndrome. The paper presents a review of the literature, and familiarizes one with the diagnosis, pathophysiology, and treatment. Two illustrative case reports are also presented.

Removal of UroLume endoprosthesis: experience of the North American Study Group for detrusor-sphincter dyssynergia application.

PURPOSE: We present the experience of the North American UroLume Multicenter Study Group with removal of the UroLume endoprosthesis. MATERIALS AND METHODS: A total of 160 neurologically impaired patients were enrolled in the North American UroLume Multicenter Study Group for detrusor external sphincter dyssynergia application. Analysis was performed in 2 groups of patients in which the device was removed during insertion and after implantation, respectively. RESULTS: Device retrieval was required during insertion in 21 patients (13%) mainly due to misplacement or migration in 17. Extraction was done with minimal complications and in all but 2 cases subsequent UroLume implantation was successful. Of 158 men with the device in place 31 (19.6%) required removal. In 34 procedures 44 devices were removed, mainly due to migration. Time from implantation to removal ranged from 4 days to 66 months (mean 22 months). The UroLume was removed en bloc in 20 cases and in parts or wire by wire in 19. The majority of patients had no or minimal complications after extraction. Only 2 patients had serious temporary complications, including bleeding and urethral injury, with no lasting consequences. No malignancy developed as a result of UroLume insertion. CONCLUSIONS: While there is a potential for urethral injury and bleeding, UroLume endoprosthesis removal is largely a simple procedure with minimal complications and consequences.

Sexual function and infertility following spinal cord injury.

Changes in sexual function and fertility frequently occur following spinal cord injury (SCI). This article presents an overview of human sexual response and the changes that occur in that response following SCI. This article addresses the issues of childbearing for women with SCI, erectile function for men with SCI, and the issues of fertility and parenting for men and women with SCI.

The reproducibility of urodynamic studies of neurogenic bladders in spinal cord injury.

OBJECTIVE: To evaluate the reproducibility (test-retest reliability) of urodynamic studies in neurogenic bladders of subjects with spinal cord injuries (SCI). DESIGN: Retrospective case series. SETTING: Urology department of a major rehabilitation center. SUBJECTS: Fifty individuals with SCI who had urodynamic studies performed from February 2000 to April 2000. MAIN OUTCOME MEASURES: Two trials (Time 1 and Time 2) of urodynamic studies done 5 minutes apart, with the following collected: bladder volume at first sensation, maximum cystometric capacity, presence of uninhibited contractions, opening pressure, maximum detrusor pressure, duration of bladder contraction, volume voided, and post-void residual (PVR) volume. The corresponding data were then compared. Statistical analysis was performed using the Lin's concordance correlation coefficient and kappa. RESULTS: Analysis of the data showed statistically significant levels of agreement between Time 1 and Time 2 with regard to the various corresponding parameters for both the filling and voiding phases. For 3 of the most important parameters-the opening pressure, maximum detrusor pressure, and duration of contraction-the Lin's concordance correlation coefficient (r(c)) was .86 (95% CI, .78-.95; p < .0005), .91 (95% CI, .86-.96; p < .0005), and .97 (95% CI, .95-.99, p < .0005), respectively. CONCLUSION: The study demonstrates good short-term intrasubject reproducibility of urodynamic studies in individuals with SCI.

Long-term followup of the North American multicenter UroLume trial for the treatment of external detrusor-sphincter dyssynergia.

PURPOSE: We determine the long-term efficacy and safety of the UroLume stent as minimally invasive treatment for external detrusor-sphincter dyssynergia in spinal cord injured men. MATERIALS AND METHODS: A total of 160 spinal cord injured men with a mean age plus or minus standard deviation of 36.3 +/- 12.1 years (range 16 to 74) were prospectively treated with an endoprosthesis at 15 centers as part of the North American UroLume trial for external detrusor-sphincter dyssynergia. Urodynamic parameters, including voiding pressure, residual urine volume and bladder capacity, were compared before treatment and at 1, 2, 3, 4 and 5 years after treatment. RESULTS: Mean voiding pressure was 75.1 +/- 28.2 cm. water before treatment in the 160 patients, and 37.4 +/- 23.9 at year 1 in 97, 39.5 +/- 22.2 at year 2 in 84, 42.6 +/- 27.3 at year 3 in 61, 46.3 +/- 33.2 at year 4 in 57 and 44.2 +/- 28.9 cm. at year 5 in 41 after stent insertion (p <0.001). Residual urine volume decreased after stent placement and was maintained throughout the 5-year followup (p <0.001). Mean cystometric capacity remained constant from 269 +/- 155 before insertion to 337 +/- 182 ml. 5 years later (p = 0.17). Hydronephrosis and autonomic dysreflexia improved or stabilized in most patients with functioning stents. Stent explant was necessary in 24 patients (15%), of whom 4 (16.7%) had another stent implanted. CONCLUSIONS: The UroLume stent demonstrates long-term safety and efficacy for the treatment of external detrusor-sphincter dyssynergia. The outcome was similar in men with and without previous sphincterotomy.

Effectiveness of neomycin/polymyxin bladder irrigation to treat resistant urinary pathogens in those with spinal cord injury.

Individuals with spinal cord injury (SCI) will sometimes develop bacterial organisms in the bladder that are resistant to oral antibiotics. This study evaluated the effectiveness of a 5-day course of intermittent neomycin/polymyxin bladder irrigation at eradicating or changing the bacterial sensitivity from parenteral to oral antibiotics. A chart review of individuals with SCI who were treated with neomycin/polymyxin bladder irrigations was performed. Inclusion criteria included the use of an indwelling catheter and the presence of asymptomatic bacteria resistant to oral antibiotics. The most common reason for treatment was eradication of resistant organisms prior to urologic testing. Bladder irrigation consisted of 3 rinses with 30 ml 3 times a day for 5 days. Pre- and post-urine samples were compared for white blood cells (WBCs), colony count and culture, and sensitivity. Chi-square tests were used to determine whether the proportion of changes in resistance or sensitivities was different from zero. The Wilcoxon Signed Rank Test was used to determine differences in bacteria, colony counts, and WBCs. Ten individuals were identified. A total of 12 neomycin/polymyxin irrigation treatments were evaluated because 2 individuals had a second series of irrigations at least 6 months apart. Nine of the 12 (75%) were considered to have successful irrigations because there was a change in culture sensitivity so that oral antibiotics would be effective post irrigation. This was statistically significant. There were no significant changes in colony counts or the number of WBCs. The authors concluded that while neomycin/polymyxin bladder irrigation did not change the type of organism, it was effective in changing resistance of most organisms. Individuals could then be treated with oral rather than intravenous or intramuscular antibiotics. Further work is needed to determine whether other variables, such as increased length of time of irrigation or increased frequency of irrigations, may actually eradicate the organisms.

Epididymal sperm transport in normal and recent spinal cord injured Sprague Dawley rats.

Causes of poor semen quality following spinal cord injury (SCI) are not known. One possible reason, based upon studies that reported improved semen quality in SCI men after several induced ejaculations, is delayed epididymal sperm transport. Our study was designed to establish baseline epididymal sperm transport values in the Sprague Dawley rat and evaluate effects of SCI on this process. Spermatozoa protamine was labeled with tritiated arginine, and the rats were sacrificed various times after injection. Each epididymis was divided into six equal sections from proximal to distal. Sperm tails were dissolved with 8 molar (M) urea in the presence of 2 mM dithiothreitol (DTT); sperm heads were collected by centrifugation (3,000 rpms, 10 min.). The radioactivity in sperm heads from each section was counted and expressed as counts per million sperm heads. To account for different rates of labeled arginine incorporation, the percentage of counts per million sperm heads in each section was calculated relative to the total number of counts in all six sections. Our results showed there was an orderly progression of sperm through the epididymis. It took 8 days for labeled sperm to enter the epididymis and 28 days to peak in the caudal (tail) section in non-SCI rats. Stasis was present 10 days after T-9 SCI in rats compared with transport in sham controls. This was evidenced by a significant increase in the percentage of labeled sperm in proximal sections of the epididymis (sections 1, 2, and 4) in T-9 transected animals (p < 0.01). If similar stasis occurs in SCI men, it could obviously contribute to poor semen quality. However, it remains to be determined how long this stasis persists after SCI in rats.

Bladder volume measurement with electrical impedance analysis in spinal cord-injured patients.

The purpose of the study contained herein was to determine the usefulness of electrical impedance for measurement of bladder volume in spinal cord-injured patients, with an assessment of the relationship between electrical impedance and bladder volume exclusively. The study was performed during urodynamic studies to match the exact bladder volume. Thirteen patients with complete spinal cord injuries were recruited. We used silver-silver chloride compound electrodes composed of one pair of current and amplitude electrodes to minimize the influence of superficial skin impedance. Each compound electrode was attached on the lower abdomen bilaterally after skin cleansing. Constant current (60 kHz-1.0 mA), converted from 9 V of direct current, was applied, and corresponding electrical impedance (omega) was measured at "pre" (before urodynamic empty bladder), "full" (with a urodynamic filled bladder), and "post" (after urodynamic empty bladder) status. Electrical impedance at the full status was definitely lower than that at the pre and post statuses in all subjects, with a statistically significant difference (P < 0. 001). The correlation between electrical impedance and bladder volume was negative (r = -0.7988), and the fact of how much the variation in electrical impedance could be explained by variation in bladder volume was estimated (r2 = 0.6381). From these findings, we have determined that the electrical impedance analysis technique can be an alternative measure of bladder volume indirectly.

The impact of urodynamic parameters on the upper tracts of spinal cord injured men who void reflexly.

Few studies have evaluated which urodynamic parameters impact the upper urinary tracts in men with complete spinal cord injuries (SCI) who void reflexly. Previous studies focused primarily on voiding pressures. This study investigated the effects of bladder wall compliance, opening pressure, maximum detrusor voiding pressure, duration of the uninhibited contraction, cystometric bladder capacity and post-void residual on vesicoureteral reflux and stasis of the upper tracts. Urodynamic studies, cystograms and renal scans of 84 consecutive men with complete SCI who void reflexly were evaluated. Of the 84 patients (168 renal units), 71 men (142 renal units) had normal upper tracts, four patients (four renal units) had vesicoureteral reflux and nine patients (15 renal units--12 bilateral, three unilateral) had upper urinary tract stasis. There was no statistical difference between those with reflux and those without reflux with regards to any urodynamic parameter evaluated. When comparing those with and without upper urinary tract stasis, the only statistically significant difference in urodynamic parameters was the duration of bladder contraction. The mean duration of the uninhibited contraction in the non-stasis group was 113.7 seconds +/- 84 seconds (1.9 minutes +/- 1.4 minutes). The mean duration of the uninhibited contraction in the stasis group was 236.4 seconds +/- 139.1 seconds (3.9 minutes +/- 2.3 minutes, p = 0.0098). In summary, the duration of bladder contraction, which reflects both detrusor and sphincter function, was found to be an important variable in those with upper tract stasis. This should be considered when evaluating and treating men with complete SCI who void reflexly.

Suppression and recovery of spermatogenesis following spinal cord injury in the rat.

Recently, we reported that changes in spermatogenesis in adult rats during acute phase (within 2 weeks) of spinal cord injury (SCI) were associated with a suppression of pituitary-testis hormone axis, and these effects mimic those that occur after hormone deprivation. In this study, we examined the long-term (>4 weeks) effects of SCI on spermatogenesis and its recovery. Results of this study reveal that while serum follicle stimulating hormone, luteinizing hormone, and testosterone levels in SCI rats recovered within 1 month after the injury, their spermatogenesis continued to regress. By 3 months, spermatogenesis in 70% of SCI rats has totally regressed, characterized by the absence of proliferating spermatogonia; these effects could not be prevented by an otherwise effective regimen of testosterone treatment. Sertoli cells in the regressed seminiferous tubules exhibited unusual behavior, characterized by the formation of multiple cell layers and/or aggregates that extended into the tubular lumen. Active spermatogenesis was observed in nine of the 19 SCI rats by 6 months, seven of which had complete spermatogenesis, but with persisting abnormalities. These results demonstrate that SCI results in total, but reversible, regression of spermatogenesis. Failure to prevent such effects by an otherwise effective exogenous testosterone regimen suggests that non-endocrine factors are involved in the SCI effects on spermatogenesis. The unusual Sertoli cell localization in the regressed testes may have been triggered by the loss of proliferating spermatogonia and may be involved in subsequent spermatogenic recovery.

Mechanical properties of bone in a paraplegic rat model.

Pathologic fractures may occur with minimal trauma after spinal cord injury (SCI) because of osteoporosis. Rats were evaluated to determine whether they could be used as an SCI animal model. Male Sprague-Dawley rats underwent spinal cord transection at the ninth thoracic vertebrae. Control rats underwent a sham procedure. Mechanical testing of the humeral shaft, femoral shaft, tibial shaft, femoral neck, distal femur, and proximal tibia was performed separately at 0, 8, and 24 weeks after surgery. At 24 weeks, significant differences between SCI and control rats were found in maximum torque needed to produce failure in the femoral shaft (63 percent of control, p < 0.05) and tibial shaft (63 percent, p < 0.01), and in compressive load to produce failure in cross-sectional specimens of the distal femur (51 percent, p < 0.05) and proximal tibia (50 percent, p < 0.01). No differences were found in the maximum torque needed to produce failure of the humeral shaft (106 percent, p = 0.77) between SCI and control rats. Reductions in relative bone strength in SCI rats at 24 weeks were similar in magnitude to bone mineral density changes reported in humans with chronic paraplegia. Thus, Sprague-Dawley rats appear to be good animal models in which to evaluate changes in bone strength following SCI.

Does refrigeration of urine alter culture results in hospitalized patients with neurogenic bladders?

A prospective, blinded study of 40 hospitalized spinal cord injured (SCI) patients was conducted to evaluate the effects of refrigeration on urinalysis and culture results. Urine samples were divided, with one aliquot examined within 4 hours and the other after 24 hours of refrigeration. Comparisons using Wilcoxon Signed Rank analysis showed no significant difference between fresh and refrigerated samples in white blood cell (WBC) count (z = -0.353, p = 0.724), number of bacteria (z = -0.772, p = 0.440), leukocytes (z = -0.277, p = 0.782), or colony counts of E. fecalis, E. coli, Citrobacter, Pseudomonas, Streptococcus, Yeast, or Acinetobacter (z = -1.00, p = 0.317; z = 0.00, p = 1.0; z = 0.00, p = 1.0; z = 0.00, p = 1.0; z = -1.00, p = 0.317; z = 0.00, p = 1.0; z = 0.00, p = 1.0, respectively). A statistically significant difference between fresh and refrigerated samples was found with "mixed" organisms (z = -2.565, p = 0.010) and a difference approaching significance was found with Staph aureus (z = -1.841, p = 0.066), both with colony counts of less than 50 k. No changes in cultures or colony counts occurred following refrigeration that would have resulted in altered treatment regimens. This study indicates that refrigeration of urine samples for up to 24 hours in the hospital setting rarely causes changes in identified organism type and causes no clinically significant changes in urinalysis or urine culture results in SCI patients.