A comparison of the urological complications associated with long-term management of quadriplegics with and without chronic indwelling urinary catheters.

The primary objective of this retrospective study was to compare the incidence of urological complications and renal deterioration in post-traumatic quadriplegic patients managed with or without a chronic indwelling urinary catheter. The charts of 57 consecutive patients who sustained traumatic cervical spinal cord injury between 1970 and 1980 were reviewed. All of the patients received the initial management or rehabilitation therapy at our institution. The unique features of this clinical review are that a large cohort of patients was followed for a minimum of 10 years, none of the 57 consecutive patients was lost to followup and a yearly excretory urogram provided an objective assessment of the renal units. The followup, and mechanism, level and degree of injury for the 32 patients managed with and 25 managed without a catheter were similar. Overall, the incidences of renal and bladder calculi, pyelonephritis, gross hematuria, penile/urethral erosion, urosepsis, urethral stricture, epididymitis and pyonephrosis were not significantly different in the catheterized and noncatheterized groups. The Kaplan-Meier analysis of the most recent excretory urogram demonstrated that the incidence of renal deterioration was also equivalent in the catheterized and noncatheterized groups. Our study suggests that the decision to manage quadriplegics with or without an indwelling catheter should not be based on relative risk of complications or renal deterioration. The decision to avoid an indwelling catheter in these patients should reflect patient comfort, convenience and quality of life.     

Neurologic complications of 405 consecutive continuous axillary catheters

Continuous axillary brachial plexus block may theoretically increase the risk of neurologic complications because of catheter-induced mechanical trauma or local anesthetic toxicity. In this study, we retrospectively reviewed the frequency of complications using current techniques and applications. There were 405 continuous axillary catheters in 368 patients. A preexisting neurologic condition was present in 41 (10.1%) patients, including 30 patients with a preoperative ulnar neuropathy. In 305 (75.3%) cases, the axillary catheter was placed to facilitate rehabilitation after major elbow surgery. Catheters were typically placed postoperatively, after documentation of the patient's normal neurologic examination. The local anesthetic infusion contained bupivacaine in 355 (88.7%) patients and mepivacaine in 45 (11.1%) patients. The mean infusion rate was 10 +/- 2 mL/h. Catheters remained indwelling for 55 +/- 32 h. In 31 patients, the axillary catheter was replaced because of technical problems or inadequate analgesia. There were 9 complications in 8 patients for an overall frequency of 2.2%. Complications included one each of the following: localized infection (treated with catheter removal and antibiotics), axillary hematoma, and retained catheter fragment requiring surgical excision. In addition, two patients reported signs and symptoms of systemic (preseizure) local anesthetic toxicity. Four (1.0%) patients reported new neurologic deficits postoperatively. In two patients, the neural dysfunction was non-anesthesia related. All four had continuous catheters placed after major elbow surgery. We conclude that the risk of neurologic complications associated with continuous axillary blockade is similar to that of single-dose techniques. IMPLICATIONS: We evaluated the risk of neurologic complications in 368 patients undergoing 405 consecutive continuous axillary blocks. New neurologic deficits were reported in four patients. This series suggests that the risk of neurologic complications associated with continuous axillary block is similar to that of single-dose techniques.     

Thrombotic complications of indwelling central catheters used for chronic hemodialysis

A new double-lumen silicone-rubber dialysis catheter, designed to be placed surgically in central veins, is now available. There is little published data concerning the long-term use of this catheter for hemodialysis, but a review of the literature suggests that pericatheter thrombus formation with or without occlusion of major veins has been a complication of chronic central venous catheterization with a variety of catheters, in both dialysis and nondialysis settings. We had this catheter placed in four diabetic patients who had severe problems related to maintenance of adequate vascular access. Two of the four patients underwent venography within 3 months of catheter placement because of impaired catheter function and were found to have thrombi on the outside of their catheters. These thrombi could not be dissolved with fibrinolytic agents, and the catheters were removed surgically without incident. The other two patients have no radiologic evidence of thrombus formation 4 and 7 months, respectively, after catheter placement. We suggest that proper selection of patients for this type of vascular access should be the subject of future studies and that patients with malfunctioning catheters undergo venography to rule out the presence of significant catheter related thrombosis.     

Survival and complications of indwelling venous catheters for permanent use in hemodialysis patients

BACKGROUND: The risk factors influencing the survival of indwelling central vein catheters and their potential complications have not been assessed in depth and on a large scale. METHODS: We investigated the general characteristics of 245 single lumen cuffed tunneled catheters and analyzed their survival by Kaplan-Meier and Cox regression analysis. Risk factors for bacteremia and thrombosis were assessed by logistic regression analysis. RESULTS: The incidence of exit-site infection, tunnel infection, bacteremia and thrombotic events was 0.35, 0.25, 1.71, and 1.94/1000 catheter days, respectively. The mean survival time per catheter was 276 days. After censoring for non catheter-related events leading to the removal of the catheter (n = 245 with 120 catheters censored and 125 events), the mean survival time of the catheter appeared to be 615 +/- 67 days (95% CI of 483-747) and the median survival time 310 +/- 50 days (95% CI of 212-408). The localization of the catheter into the right internal jugular vein results in significantly better survival as compared with other insertion sites both in Kaplan-Meier (mean survival of 650 days compared to a mean survival of 519 days, P value < 0.009) and in Cox regression analysis (relative risk of 0.537, P value < 0.001). Localization of the catheter into the right internal jugular vein seemed to increase the risk for bacteremia (relative risk of 1.798, P value of 0.063). The use of anticoagulant agents was not protective for thrombosis, although this might be due to lack of power (relative risk of 0.626, P value of 0.141). CONCLUSION: We provide evidence of a mean survival in long-term hemodialysis catheter close to 2 years with an acceptable complication rate. If a long-term hemodialysis catheter is required, it is best placed in the right internal jugular vein.     

Formation of encrustations on indwelling urinary catheters in the elderly: a comparison of different types of catheter materials in "blockers" and "nonblockers"

In order to determine the effect of catheter materials on formation of encrustations in long-term indwelling urinary catheters in the elderly we performed a crossover study utilizing commercially available silicone, silicone-coated, teflon-coated and latex catheters that were left in place for 14 days. The study was conducted with #18 french catheters fitted with a 30 ml. balloon since smaller size catheters frequently fell out spontaneously. The distinction between patients who were "blockers" and "nonblockers" was found to be clinically useful since "nonblockers", who constituted about half the population, did well regardless of type of catheter material used. Formation of encrustations and blockage was significantly less in "blockers" with silicone than with teflon-coated or latex catheters. The more rapid flow-time through silicone catheters appears to be related to a larger bore. Although this study supports the use of silicone catheters for "blockers" on long-term drainage the results should not be interpreted to imply that they are preferable to other types of catheters for short-term use or to changing less expensive catheters more frequently when needed.     

The development of bacterial biofilms on indwelling urethral catheters

The biofilm mode of growth has been implicated in the majority of human bacterial infections. In the urinary tract, notable biofilm-associated infections include prostatitis, chronic cystitis, struvite urolithiasis, and catheter-associated infections. Biofilms protect the causative organisms from host defences and antimicrobial therapy. Biofilm formation has traditionally been considered to result from adhesion and capsule formation by adherent microorganisms. Recent work has shown that a large number of genes are activated during this process, some of which have been associated with twitching motility, quorum sensing, and slow growth. In this paper, we review some of the recent work on biofilm biology and highlight its role in urinary tract infections, particularly those associated with urinary catheters.     

Removal of short-term indwelling urethral catheters: the evidence.

OBJECTIVE: The objective of this systematic review was to determine the effect of the timing of removal of indwelling urethral catheters (IUCs) on the duration to and volume of first void, length of hospitalization, number of patients developing urinary retention and requiring recatheterization, patient satisfaction, and the percentage of IUCs removed according to the scheduled time for removal. MATERIALS AND METHODS: Published and unpublished literature in English and other languages between January 1966 and June 2002, which compared the effects of the timing of removal of short-term indwelling urethral catheters on patient outcomes, was systematically reviewed using multiple electronic databases.To determine eligibility of the trials for inclusion in the review, assessment of methodologic quality and data extraction was undertaken independently by 2 reviewers and verified by a third reviewer. Odds ratio (OR) for dichotomous data and a weighted mean difference for continuous data were calculated with 95% confidence intervals (CI). Where synthesis was inappropriate, a narrative overview has been undertaken. RESULTS: Eight randomized controlled trials were eligible for this review. When IUCs were removed at midnight, the time to first void was significantly shorter (P = .012) after gynecologic surgery and significantly longer in patients after urologic surgery and procedures. Seven trials reported that the volume of the first void was greater in patients whose IUCs were removed late at night, and this was statistically significant in 4 trials.Patients who had their IUC removed at midnight were discharged from the hospital significantly (P < .00001) earlier than those who had their IUC removed in the morning, a finding that could result in potential cost savings for hospitals. CONCLUSION: Based on the limited available evidence, this article suggests benefits in terms of patient outcomes and reduction in the length of hospitalization after midnight removal of the IUCs. Further trials should be undertaken in wider settings and on specific groups of patients to enhance generalizability.     

Heparin coating on ureteral Double J stents prevents encrustations: an in vivo case study

PURPOSE: To evaluate the ability of heparin coating to inhibit Double J stent encrustation and compare it with the classic polyurethane Double J stent. PATIENTS AND METHODS: The study involved five patients with bilateral obstructions, who required bilateral ureteral Double J stent placement. Every patient received a heparin-coated Double J stent and a traditional polyurethane Double J stent for 1 month. After removal, the stents were analyzed using field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and micro-infrared spectrophotometry (Micro-IR). These same techniques were used to analyze the heparin-coated and uncoated stents before insertion. The thickness, extension, and composition of encrustation of the coated and uncoated stents were compared. Moreover, two heparin-coated stents were analyzed with the same techniques after they had been in place for 10 and 12 months. RESULTS: FESEM analysis showed that the difference in encrustation thickness and extension between the two groups was significant. EDS and Micro-IR confirmed that in the heparinized stents the encrustations were not as uniform and compact as those in the uncoated stents. The stents that were left in place long-term were free of encrustations and had no changes in the heparin layer. CONCLUSIONS: Heparin coating reduces stent encrustation. Moreover, as no changes were seen in the heparin layer, we concluded that covalent heparin bonding enhances its adhesion to the polyurethane surface and ensures its stability for long periods. The heparin-coated stent appears to be a useful tool for long-term urinary drainage.     

A clinical assessment of the performance of a sensor to detect crystalline biofilm formation on indwelling bladder catheters

OBJECTIVES: To test the ability of a sensor developed to signal infection by the organisms that generate the crystalline biofilms that encrust catheters, to give an early warning that encrustation was occurring on patients' catheters, as the care of many patients undergoing long-term bladder catheterization is complicated by the encrustation and blockage of their catheters. PATIENTS AND METHODS: Twenty patients were followed prospectively for the lifetime of one of their catheters. Sensors based on cellulose acetate/bromothymol blue were placed in the urine-collection bags, which were changed as usual at weekly intervals. The bacteriology was assessed and pH determined weekly on urine samples. Photographic records were made of the sensors twice weekly. On removal, each catheter was examined for encrustation and blockage. RESULTS: Proteus mirabilis was not isolated from five patients and in these cases the sensor colour remained golden-yellow to brown. The catheters drained for the scheduled period and showed no signs of encrustation. By contrast, the sensors turned dark blue/black in the urine of all 15 patients infected with P. mirabilis. All these patients' catheters were encrusted and in 12 the catheters blocked. The mean interval between the sensor signalling and the catheter blocking was 12 days. CONCLUSION: The cellulose acetate/bromothymol blue sensors placed in the urine collection bags are capable of signalling infection by P. mirabilis. They also signal the early stages of catheter encrustation and allow catheter replacement in ample time to avoid the clinical crises and emergency referrals caused by catheter blockage.     

Placement and complications of monitoring catheters

Vascular access is a necessary evil in critically ill patients, a population that is at high risk for complications. Appropriate planning and attention to detail minimize the associated risks while maximizing the benefits derived from catheter use.     

Clamping short-term indwelling catheters: a systematic review of the evidence.

OBJECTIVE: The objective of this review is to determine the effects of clamping short-term indwelling urethral catheters before removal on the incidence of urinary tract infection, time to first void, voiding dysfunction, incidence of recatheterization, and the length of hospital stay. MATERIALS AND METHODS: Published and unpublished randomized and quasi-randomized controlled trials, completed between January 1966 and July 2004, in English and other languages that compared the effects of clamping short-term indwelling urethral catheters, were systematically reviewed using multiple electronic databases. Determination of eligibility of trials for inclusion in the review, assessment of methodological quality, and data extraction were undertaken independently by 2 reviewers. Relative risks for dichotomous data and a weighted mean difference for continuous data were calculated with 95% confidence intervals. Where synthesis was inappropriate, a narrative overview has been undertaken. RESULTS: Three trials that investigated the effect of clamping the indwelling urethral catheter compared to free drainage before removal were eligible for inclusion. Two trials reported no significant difference in the incidence of urinary tract infection (UTI), number of patients who developed urinary retention or required recatheterization, and the length of hospital stay between the 2 groups. Another reported that the postvoid residual urine volume for patients who did not receive reconditioning of the bladder increased from 4.25 mL at baseline to 42.25 mL after removal of the indwelling urethral catheter, whereas the residual urine volume for patients who received reconditioning increased from 17.25 mL at baseline to 22 mL at follow-up. CONCLUSIONS: The evidence for clamping indwelling urethral catheters before removal remains equivocal. Given the current state of evidence, procedures relating to clamping of indwelling urinary catheters should not be initiated. Until stronger evidence becomes available, however, practices relating to clamping indwelling urethral catheters will continue to be dictated by local preferences and cost factors.     

In vitro investigations into the formation and dissolution of infection-induced catheter encrustations.

Encrustations are the most frequent complications occurring with indwelling catheters and urine drainage systems. The conditions for bacterial infections, using synthetic urine and controlled contamination by Proteus vulgaris, were standardised by using an in vitro model. Crystal deposits on catheters were analysed by infra-red spectroscopy and scanning electron microscopy. The main components of deposits in all investigations were struvite (MgNH4PO4.6H2O) 60-70% and carbonate apatite (Ca10(PO4,CO3)6 (OH,CO3)2) 30-40%. Investigations as to the quality and quantity of encrustations confirmed the analysis. Irrigation treatment was carried out with physiological saline solution and citric acid solution (Suby G) to study and quantify the dissolution of crystal deposits. Regular irrigation with citric solution resulted in a 70% dissolution of encrustations and ensured free flow as ascertained by measuring flow rates.