Clinical trial of junction seals for the prevention of urinary catheter-associated bacteriuria.

BACKGROUND: Preconnected catheter systems with sealed junctions have been associated with reduced rates of bacteriuria and mortality. A clinical trial was undertaken to evaluate the effectiveness of a junction seal applied after catheter insertion for preventing bacteriuria and reducing mortality. METHODS: Patients undergoing transurethral catheterization at a community hospital were randomized within 24 hours of catheter insertion to receive either a tape seal applied to the catheter-drainage tubing junction or no tape seal. Catheter urine cultures and catheter care violations were monitored daily until catheter removal or patient discharge. RESULTS: Overall, 124 (13.7%) of 903 patients in the group receiving a junction seal acquired bacteriuria, compared with 125 (14.9%) of 837 patients in the control group (P = .52, odds ratio = 0.91, 95% confidence interval, 0.69 to 1.20). Multivariate analysis revealed that only female gender and lack of systemic antibiotic use independently correlated with the development of bacteriuria; neither junction treatment randomization nor disconnection of the junction was associated with bacteriuria. Survival curve analysis of patients stratified by gender and antibiotic use revealed no significant differences in the rate of bacteriuria between treatment groups. The overall mortality in the tape seal group was less than that in the control group (6.6% vs. 8.0%, respectively), but not to a statistically significant extent despite stratification by antibiotic use. CONCLUSIONS: The use of a tape seal applied to the catheter-drainage tubing junction within 24 hours of catheter insertion was not associated with significantly lower rates of bacteriuria and mortality in patients undergoing short-term catheterization.

A large randomized clinical trial of a silver-impregnated urinary catheter: lack of efficacy and staphylococcal superinfection.

PURPOSE: The antibacterial activity of silver-containing compounds has recently been employed in constructing medical devices, such as vascular and urinary catheters, that may be effective in blocking infection. The present study was designed to evaluate the efficacy of a silver oxide-coated urinary catheter. PATIENTS AND METHODS: A total of 1,309 hospitalized patients who required placement of an indwelling urinary catheter for 24 hours or longer were randomly assigned to receive either a silicone catheter coated externally with 5% silver oxide or a standard silicone elastomer-coated latex catheter. Daily catheter-urine specimens were collected aseptically and catheter-care violations were monitored daily for the duration of the catheterization. RESULTS: Bacteriuria developed in 85 of 745 patients (11.4%) in the silver-coated catheter group and in 73 of 564 patients (12.9%) in the control group (P = 0.45). In women who did not receive antibiotics, the rates were 29.3% and 30.4%, respectively (P = 0.98). In men who did not receive antibiotics, the rate of bacteriuria was significantly higher with the silver-coated catheter (29.4% compared to 8.3%, respectively, P = 0.02). Staphylococcal species were isolated more often from the silver-coated catheter group than from the control group (25% versus 8% of all isolates, respectively, P = 0.002). CONCLUSIONS: This study, the largest ever reported evaluating any silver-impregnated device, has not only failed to demonstrate the efficacy of silver in prevention of catheter-associated bacteriuria, as suggested in prior studies, but it has also shown a significantly increased incidence of bacteriuria in male patients and a significantly increased occurrence of staphylococcal bacteriuria. These results suggest the need for caution and for similar large-scale trials before silver-containing compounds are widely used for preventing device-associated infections, both in vascular and urinary catheters.

Skin and heart allograft prolongation in tilorone-treated rats.

Tilorone is a synthetic amino-alkoxyfluorenone with demonstrated antiviral and antitumor properties. This study gives evidence for immunosuppressive properties of the substance as well. Buffalo rats (AgB6) received skin grafts from rats of the Fischer (AgB1) strain. Control animals rejected in 9.9 +/- 1.1 days, compared to 13.7 +/- 2.3 days for recipients treated with Tilorone. Steroids when combined with Tilorone further prolonged skin allografts to 16.7 +/- 2.6 days. Heart allografts from Fischer (AgB1) and Brown-Norway (AgB3) to Lewis (AgB1) also were performed. In the Fischer to Lewis combination, allograft survival was prolonged from 14.7 +/- 1.0 to 31.0 +/- 3.8 days. In the Brown-Norway to Lewis combination, treated rats rejected in 10.2 +/- 1.4 days versus 6.6 +/- 1.1 days for controls. Increased levels of cytotoxic antibody specific to lymphocytes of the donor strain were noted in Tilorone-treated animals. The mechanism by which Tilorone prolongs allografts may well involve a combination of interferon production and specific suppression of thymus-derived lymphocytes.

Daily meatal care for prevention of catheter-associated bacteriuria: results using frequent applications of polyantibiotic cream.

OBJECTIVE: To determine the efficacy of meatal treatment with a polyantibiotic cream in the prevention of bacteriuria during transurethral bladder catheterization. DESIGN: Randomized controlled trial. SETTING: Community teaching hospital. PATIENTS: Adult patients who underwent closed urinary catheter drainage for short and intermediate durations (two to 30 days). INTERVENTION: Polyantibiotic cream containing polymyxin B sulfate, neomycin sulfate, and gramicidin was applied to the urethral meatus-catheter interface three times daily from the first day of catheterization until bacteriuria was found. The onset of bacteriuria was defined as the day the colonizing species first achieved a colony count of greater than or equal to 1000 colonies/ml. Patients randomized to the control group received routine meatal care with cleansing of the meatal surface during daily bathing. RESULTS: Among 2,923 patients who were randomly allocated to receive either the protocol meatal care or routine care, the evaluable study population consisted of 747 patients who were nonbacteriuric and who remained catheterized for more than two days. Overall, 26 (6.8%) of 383 patients given the polyantibiotic treatment acquired bacteriuria, as compared to 37 (10.1%) of 364 patients not given this treatment (p = .167). A Cox proportional hazards regression analysis showed that, among putative risk factors including lack of meatal care, only female gender, a meatal swab culture yielding gram-negative rods or enterococci, and lack of antibiotic use during catheterization were independently associated with the development of bacteriuria. CONCLUSIONS: The adverse effect of meatal care noted in earlier studies of a disinfectant ointment applied twice daily was not found in this study of an antimicrobial preparation in a cream vehicle applied three times daily. However, the results do not support meatal care as an efficacious method to prevent catheter-associated bacteriuria in all patients.

Surveillance for quality assessment: IV. Surveillance using a hospital information system.

Hospital surveillance for infection control purposes is a well-accepted method of following nosocomial infections in U.S. hospitals. However, hospital surveillance is being increasingly performed for nosocomial events in noninfectious areas, such as quality assurance and other areas of outcomes research. For the continued development of hospital surveillance in all these areas, dramatic growth in the amount of information collected will occur. To accommodate this growth and to validate new approaches in these areas, large amounts of data collection will be necessary. Collection of these data will be quite difficult without the creation of clinical hospital data bases in which large amounts of information are collected as a routine part of patient care, not as an elaborate addition to patient care. Automated hospital information systems, such as the HELP system, can facilitate the conduct of ongoing hospital surveillance not only in infection control but also in a broad range of areas, such as quality improvement outcomes research and cost-containment areas.

Risk factors for epidemic Xanthomonas maltophilia infection/colonization in intensive care unit patients.

OBJECTIVE: To determine risk factors for and modes of transmission of Xanthomonas maltophilia infection/colonization. DESIGN: Surveillance and cohort study. SETTING: A 470-bed tertiary trauma-referral community hospital. PATIENTS: From January 1, 1988 to March 17, 1989, 106 intensive care unit patients developed X maltophilia infection/colonization. We defined a case as any intensive care unit patient who, from July 15, 1988, through March 17, 1989 (epidemic period), had X maltophilia infection/colonization greater than or equal to 48 hours after intensive care unit admission. We identified 45 case patients and 103 control patients (persons in the shock-trauma intensive care unit for greater than or equal to 72 hours during the epidemic period who had no X maltophilia-positive culture). RESULTS: Cases were significantly more likely to occur in the shock-trauma intensive care unit than in all other intensive care units combined. Mechanical ventilation, tracheostomy, being transported to the hospital by airplane, and receipt of a higher mean number of antimicrobials were risk factors for X maltophilia infection/colonization. Risk of X maltophilia infection/colonization was significantly greater among cases exposed to a patient with a X maltophilia surgical wound infection than among those without such exposure (relative risk = 1.3, p = .03). Animate and inanimate cultures revealed X maltophilia contamination of the hospital room of a patient with an X maltophilia surgical wound infection, of respiratory therapy equipment in this patient's room, of respirometers shared between patients, and of shock-trauma intensive care unit personnel's hands. Related environmental and clinical isolates were serotype 10. CONCLUSIONS: Mechanically ventilated patients receiving antimicrobials in the shock-trauma intensive care unit were at increased risk of X maltophilia infection/colonization. Patients with draining X maltophilia surgical wound infections served as reservoirs for X maltophilia, and contamination of the respirometers and the hands of shock-trauma intensive care unit personnel resulted in patient-to-patient transmission of X maltophilia.

Prevention of catheter-associated bacteriuria: clinical trial of methods to block three known pathways of infection.

The simultaneous use of methods to block all three known pathways of bacterial entry into the bladders of catheterized patients has been suggested because of the limited effectiveness of individual methods that block single pathways. We conducted a randomized controlled trial to assess the prevention of bacteriuria in patients, using a three-way system that included a hydrophilic polymer-coated and preconnected sealed catheter system, daily catheter care, and disinfection of the outflow tube of the drainage bag with povidone-iodine (i.e., methods to block bacterial entry at the urethral insertion site, at the catheter drainage tube junction, and at the outflow tube). Among treated patients, 14 (4.7%) of 300 acquired bacteriuria as compared with 15 (4.9%) of 306 who did not receive the protocol treatments. Only 3 of 29 episodes of bacteriuria occurred in patients whose meatal cultures did not contain gram-negative bacilli or enterococci; thus migration of bacteria in the periurethral mucous sheath appeared to be the most common pathway by which bacteria gained entry into the bladder in this study. Catheter care and disinfection of the drainage bag outflow tube as used in this study remain unproven methods of preventing catheter-associated bacteriuria. Preconnected catheters with junction seals were used in both treated and untreated patients and, on the basis of previous studies, appear to be effective in reducing junction disconnections and bacteriuria. Therefore we conclude that the use of several simultaneous measures to prevent catheter-associated urinary infections is no more effective than the use of preconnected catheters with junction seals alone and is clearly more expensive.

Computerized identification of patients at high risk for hospital-acquired infection.

Surveillance for hospital-acquired infections is required in U.S. hospitals, and statistical methods have been used to predict the risk of infection. We used the HELP (Health Evaluation through Logical Processing) Hospital Information System at LDS Hospital to develop computerized methods to identify and verify hospital-acquired infections. The criteria for hospital-acquired infection are standardized and based on the guidelines of the Study of the Efficacy of Nosocomial Infection Control and the Centers for Disease Control. The computer algorithms are automatically activated when key items of information, such as microbiology results, are reported. Computer surveillance identified more hospital-acquired infections than did traditional methods and has replaced manual surveillance in our 520-bed hospital. Data on verified hospital-acquired infections are electronically transferred to a microcomputer to facilitate outbreak investigation and the generation of reports on infection rates. Recently, we used the HELP system to employ statistical methods to automatically identify high-risk patients. Patient data from more than 6000 patients were used to develop a high-risk equation. Stepwise logistic regression identified 10 risk factors for nosocomial infection. The HELP system now uses this logistic-regression equation to monitor and determine the risk status for all hospitalized patients each day. The computer notifies infection control practitioners each morning of patients who are newly classified as being at high risk. Of 605 hospital-acquired infections during a 6-month period, 472 (78%) occurred in high-risk patients, and 380 (63%) were predicted before the onset of infection. Computerized regression equations to identify patients at risk of having hospital-acquired infections can help focus prevention efforts.

Gauging the severity of surgical sepsis.

I developed a method for scoring the severity of a septic process, based on deteriorated functions in seven key organ systems of the body. The scoring system is numeric and recognizes that the risk to a patient rises geometrically as organ-system functions deteriorate step by step. The scoring system was validated by reviewing the clinical course of 30 patients with sepsis. Prognosis and hospital stay correlated well with individual scores. The scoring system offered more accurate comparisons in clinical studies of infected patients and helped follow up a patient with sepsis more accurately.

The HELP system and its application to infection control.

The HELP system is a comprehensive hospital information system that is linked to an allied financial data base. The clinical data base integrates information from areas such as admitting, pharmacy, radiology, surgery, pathology, nursing, respiratory therapy, and the clinical laboratories, including microbiology. This allows for the creation of an electronic medical record that contains all the clinical and financial data for each patient. The HELP system combines both communication and advice features through the use of data- and time-driven algorithms. We have used the HELP system to automate the surveillance and analysis of hospital-acquired infections and to identify patients at high risk for nosocomial infection. The expert system features have also been used to suggest alternatives for patients receiving inappropriate antimicrobial therapy, to improve the timing of antibiotic prophylaxis in surgery, and to curtail unnecessarily prolonged prophylaxis. Automated hospital information systems such as HELP can facilitate the investigation of a broad range of infection control, quality improvement, and cost-containment issues.

Reduction of acute tubular necrosis (ATN) by furosemide and steroids in cadaveric kidney recovery.

One hundred fifty human cadaver kidneys have been preserved by a combination of topical hypothermia and pulsatile perfusion with cryoprecipitated plasma in our laboratory. Post-transplant acute renal failure was reduced from 58 to 21 per cent in those kidneys protected with furosemide and methylprednisolone.

Analysis of chlorhexidine sorption in soft contact lenses by catalytic oxidation of [14C]chlorhexidine and by liquid chromatography.

Two methods are described for the analysis of chlorhexidine sorption in soft contact lenses. The first is an isocratic ion-pairing high-performance liquid chromatographic (HPLC) method with UV detection at 220 nm that allows the determination of chlorhexidine, p-chloroaniline, and other chlorhexidine degradation products in ophthalmic solutions. This procedure had a detection limit of 0.1 ng. The second involves the catalytic oxidation of the lens matrix containing [14C]chlorhexidine to [14C]carbon dioxide and water. The label is then trapped as carbon dioxide in a cocktail and is analyzed by liquid scintillation counting. These methods are sensitive, accurate, and reproducible, and can be used independently or in conjunction for the determination of chlorhexidine sorption in soft contact lenses.

Corticosteroids in organ preservation.

1. Glucocorticoids have been empirically employed during perfusion preservation of transplantable organs. 2. Use of corticosteroids in organ preservation is based on their pharmocologic binding of released lysosomal enzymes, as membrane stabilizers, peripheral vasodilators, and inhibitors of the inflammatory response. 3. The incidence post-transplant of ATN in cadaveric kidney preservation by pulsa-tile perfusion has been reduced from 57% to 18% when the donor was protected with large doses of M-P. 4. There is sufficient clinical and laboratory evidence to substantiate the use of large doses of M-P given to the prospective donor as a protective agent against ischemic injury in organ recovery.

Triple-stranded stainless steel wires--evaluation of mechanical properties and comparison with titanium alloy alternatives.

Force storage and delivery properties of typical triple-stranded stainless steel wires are determined and compared with reported values for titanium alloy archwires. Results indicate that triple-stranded wires can often provide a viable alternative to the newer titanium alloys.