Catheter-associated urinary tract infections in intensive care units

APSIC guide for prevention of catheter associated urinary tract infections (CAUTIs)

BACKGROUND

The Asia Pacific Society of Infection Control launched the APSIC guide for prevention of catheter associated urinary tract infections in July 2022. It aims to highlight practical recommendations in a concise format designed to assist healthcare facilities in the Asia Pacific region to achieve high standards in infection prevention and control practices during the management and care of patients with a urinary catheter.

METHODS

The guidelines were developed by an appointed workgroup comprising experts in the Asia Pacific region, following reviews of previously published guidelines and recommendations relevant to each section.

RESULTS

It recommends that healthcare institutions have a catheter associated urinary tract infection prevention program that includes surveillance and the use of the insertion and maintenance bundles. Implementation of the bundles is best done using a quality improvement approach with a multidisciplinary team.

CONCLUSIONS

Healthcare facilities should aim for excellence in care of patients with urinary catheters. It is recommended that healthcare facilities have a catheter associated urinary tract infection prevention program as part of their Infection Prevention and Control program.

Highly Durable Antimicrobial Tantalum Nitride/Copper Coatings on Stainless Steel Deposited by Pulsed Magnetron Sputtering

Highly durable and antimicrobial tantalum nitride/copper (TaN/Cu) nanocomposite coatings were deposited on D-9 stainless steel substrates by pulsed magnetron sputtering. The Cu content in the coating was varied in the range of 1.42-35.42 atomic % (at.%). The coatings were characterized by electron probe microanalyzer, X-ray diffraction, scanning electron microscope and atomic force microscope. The antibacterial properties of the TaN/Cu coatings against gram-negative Pseudomonas aeruginosa were evaluated using a cell culture test. The peak hardness and Young's modulus of TaN/Cu with 10.46 at.% Cu were 24 and 295 GPa, respectively, which amounted to 15 and 41.67% higher than Cu-free TaN. Among all, TaN/Cu with 10.46 at.% exhibited the lowest friction coefficient. The TaN/Cu coatings exhibited significantly higher antibacterial activity than Cu-free TaN against Pseudomonas aeruginosa. On TaN, the bacterial count was about 4 × 10⁶ CFU, whereas it was dropped to 1.2 × 10² CFU in case of TaN/Cu with 10.46 at.% Cu. The bacterial count was decreased from 9 to 6 when the Cu content increased from 25.54 to 30.04 at.%. Live bacterial cells were observed in the SEM images of TaN, and dead cells were found on TaN/Cu. Overall, TaN/Cu with 10.46 at.% Cu was found to be a potential coating composition in terms of higher antimicrobial activity and mechanical durability.

Factors Associated With Healthcare-Acquired Catheter-Associated Urinary Tract Infections: Analysis Using Multiple Data Sources and Data Mining Techniques

PURPOSE

The purpose of this study was to identify factors associated with healthcare-acquired catheter-associated urinary tract infections (HA-CAUTIs) using multiple data sources and data mining techniques.

SUBJECTS AND SETTING

Three data sets were integrated for analysis: electronic health record data from a university hospital in the Midwestern United States was combined with staffing and environmental data from the hospital's National Database of Nursing Quality Indicators and a list of patients with HA-CAUTIs.

METHODS

Three data mining techniques were used for identification of factors associated with HA-CAUTI: decision trees, logistic regression, and support vector machines.

RESULTS

Fewer total nursing hours per patient-day, lower percentage of direct care RNs with specialty nursing certification, higher percentage of direct care RNs with associate's degree in nursing, and higher percentage of direct care RNs with BSN, MSN, or doctoral degree are associated with HA-CAUTI occurrence. The results also support the association of the following factors with HA-CAUTI identified by previous studies: female gender; older age (>50 years); longer length of stay; severe underlying disease; glucose lab results (>200 mg/dL); longer use of the catheter; and RN staffing.

CONCLUSIONS

Additional findings from this study demonstrated that the presence of more nurses with specialty nursing certifications can reduce HA-CAUTI occurrence. While there may be valid reasons for leaving in a urinary catheter, findings show that having a catheter in for more than 48 hours contributes to HA-CAUTI occurrence. Finally, the findings suggest that more nursing hours per patient-day are related to better patient outcomes.

Diagnostic accuracy of urinary dipstick to exclude catheter-associated urinary tract infection in ICU patients: a reappraisal

OBJECTIVES

We wanted to assess the diagnostic accuracy of urinary dipstick testing in excluding catheter-associated urinary tract infection (CAUTI) in intensive care unit (ICU) patients with fever or hypothermia.

METHODS

This was a prospective observational cohort study in a medical-surgical ICU. Patients with new-onset fever >38.3 °C or hypothermia <36 °C at least 48 h after urinary catheter insertion were included over a 2-year period. At each episode, a urinary dipstick test and a urine culture were performed as the criterion standard. Extensive microbiological investigations for extra-urinary infections were performed also. The performances of various urinary dipstick result combinations in ruling out CAUTI were compared based on the likelihood ratios (LR+ and LR-).

RESULTS

Symptomatic CAUTI was diagnosed in 31 (24.4 %) of the 127 included patients (195 episodes of fever or hypothermia). LR+ was best for combined leukocyte esterase-positive and nitrite-positive dipstick results (overall population: 14.91; 95 % confidence interval [95 % CI], 5.53-40.19; patients without urinary symptoms: 15.63; 95 % CI, 5.76-42.39). LR- was best for either leukocyte esterase-positive or nitrite-positive dipstick results (overall population: 0.41; 95 % CI, 0.57-0.65; patients without urinary symptoms, 0.36; 95 % CI, 0.21-0.60).

CONCLUSIONS

Urinary dipstick testing at the bedside does not help to rule out symptomatic CAUTI in medical or surgical ICU patients with fever or hypothermia.

Control of pathogen growth and biofilm formation using a urinary catheter that releases antimicrobial nitrogen oxides

Antibacterial nitrogen oxides including nitric oxide are formed from nitrite under acidic conditions. In a continuous-flow model of the urinary bladder we used the retention cuff of an all-silicone Foley catheter as a depot for export of nitrogen oxides. The cuff was filled with sodium nitrite (50mM) and an acidic buffer solution (pH 3.6) and the growth of nine common uropathogens in the surrounding artificial urine was measured along with biofilm formation on the catheter surface. In experiments with control catheters (NaCl) bacteria grew readily and biofilm developed within hours in five of nine strains. In contrast, with test catheters bacterial counts were markedly reduced and biofilm formation by Pseudomonas aeruginosa, Klebsiella pneumoniae, and Enterobacter cloace was prevented, whereas Escherichia coli and Staphylococcus aureus were unaffected. We conclude that antibacterial nitrogen oxides generated in the retention cuff of a urinary catheter diffuse into urine and prevent the growth of urinary pathogens and biofilm formation. Although promising, future studies will reveal if this novel approach can be clinically useful for the prevention of catheter-associated urinary tract infections.

A Pilot Study on Prevention of Catheter-Related Urinary Tract Infections with Fluoroquinolones

The objective of this multicenter, randomized, controlled, parallel group trial was to evaluate the efficacy of levofloxacin 250 mg oral, once daily (LVFX), placebo one tablet oral once daily (Placebo [P] group) and ciprofloxacin (CPFX) 500 mg oral, twice daily (single blind), prophylaxis in preventing bacteriuria (> or = 10(3) CFU/ml) in post-surgical catheterized patients. In the modified intention-to-treat (M-ITT) population of the 82 enrolled patients, negative bacteriuria was observed in 92% of LVFX group, in 80% of P group and in 100% of CPFX group while in the per-protocol (PP) population figures were: 100%, 86.4% and 100% respectively. Only one symptomatic urinary tract infection and one surgical wound infection were observed in the P group. Both drugs were well tolerated, showing a safety profile comparable to placebo. The high frequency of negative bacteriuria in the placebo group sounds encouraging as it underlines that the adoption of closed urinary drainage system catheters in hospital setting may reduce the frequency of hospital-acquired infections.

Jaundice increases the rate of complications and one-year mortality in patients with hypoxic hepatitis

Hypoxic hepatitis (HH) is the most frequent cause of acute liver injury in critically ill patients. No clinical data exist about new onset of jaundice in patients with HH. This study aimed to evaluate the incidence and clinical effect of jaundice in critically ill patients with HH. Two hundred and six consecutive patients with HH were screened for the development of jaundice during the course of HH. Individuals with preexisting jaundice or liver cirrhosis at the time of admission (n = 31) were excluded from analysis. Jaundice was diagnosed in patients with plasma total bilirubin levels >3 mg/dL. One-year-survival, infections, and cardiopulmonary, gastrointestinal (GI), renal, and hepatic complications were prospectively documented. New onset of jaundice occurred in 63 of 175 patients with HH (36%). In patients who survived the acute event of HH, median duration of jaundice was 6 days (interquartile range, 3-8). Patients who developed jaundice (group 1) needed vasopressor treatment (P < 0.05), renal replacement therapy (P < 0.05), and mechanical ventilation (P < 0.05) more often and had a higher maximal administered dose of norepinephrine (P < 0.05), compared to patients without jaundice (group 2). One-year survival rate was significantly lower in group 1, compared to group 2 (8% versus 25%, respectively; P < 0.05). Occurrence of jaundice was associated with an increased frequency of complications during follow-up (54% in group 1 versus 35% in group 2; P < 0.05). In particular, infections as well as renal and GI complications occurred more frequently in group 1 during follow-up.

CONCLUSION

Jaundice is a common finding during the course of HH. It leads to an increased rate of complications and worse outcome in patients with HH.

Urethral catheter-related urinary infection in critical patients admitted to the ICU. Descriptive data of the ENVIN-UCI study

OBJECTIVE

To describe trends in national catheter-related urinary tract infection (CRUTI) rates, as well as etiologies and multiresistance markers.

DESIGN

An observational, prospective, multicenter voluntary participation study was conducted from 1 April to 30 June in the period between 2005 and 2010.

SETTING

Intensive Care Units (ICUs) that participated in the ENVIN-ICU registry during the study period.

PATIENTS

We included all patients admitted to the participating ICUs and patients with urinary catheter placement for more than 24 hours (78,863 patients).

INTERVENTION

Patient monitoring was continued until discharge from the ICU or up to 60 days.

VARIABLES OF INTEREST

CRUTIs were defined according to the CDC system, and frequency is expressed as incidence density (ID) in relation to the number of urinary catheter-patients days.

RESULTS

A total of 2329 patients (2.95%) developed one or more CRUTI. The ID decreased from 6.69 to 4.18 episodes per 1000 days of urinary catheter between 2005 and 2010 (p<0.001). In relation to the underlying etiology, gramnegative bacilli predominated (55.6 to 61.6%), followed by fungi (18.7 to 25.2%) and grampositive cocci (17.1 to 25.9%). In 2010, ciprofloxacin-resistant E. coli strains (37.1%) increased, as well as imipenem-resistant (36.4%) and ciprofloxacin-resistant (37.1%) strains of P. aeruginosa.

CONCLUSIONS

A decrease was observed in CRUTI rates, maintaining the same etiological distribution and showing increased resistances in gramnegative pathogens, especially E. coli and P. aeruginosa.

Study of nosocomial urinary tract infections in a pediatric intensive care unit

Nosocomial urinary tract infections (NUTI) are one of the commonest infections in a Pediatric Intensive Care Unit (PICU). This prospective study was conducted in PICU between January and December 2008 to study the incidence, organisms and risk factors for NUTI. A total of 287 consecutive patients with >48 h PICU stay and sterile admission urine culture, were enrolled and monitored for NUTI (defined as per CDC criteria 1988) till discharge or death. Patients with and without NUTI were compared with respect to demographics, PRISM scores, primary diagnosis, nutritional status and device utilization to identify risk factors. Outcome was defined as length of PICU stay and survival or death. There were 69 episodes of UTI in 60 (20.9%) patients; incidence being 18 episodes/1000 patient days. Candida (52.1%) and Enterococcus (13%) were commonest followed by Escherichia coli (11.6%) and Klebsiella pneumoniae (10.1%). Catheterization and duration of catheterization were the risk factors for NUTI (p < 0.001). The median length of PICU stay was significantly longer in NUTI group compared to non-NUTI group (19 vs. 8 days, p = 0.001). Mortality rates in both the groups were similar.

[Urinary tract colonization and infection in critically ill patients]

Urinary tract infections (UTIs) account for 20-50% of all hospital-acquired infections occurring in the intensive care unit (ICU). In some reports UTI was found to be more frequent than hospital-acquired pneumonia and intravascular device bacteremia, with a greater incidence in developing countries. The risk factors associated with the appearance of UTI include the severity of illness at the time of admission to the ICU, female status, prolonged urinary catheterization or a longer ICU stay and poor urinary catheter management - mainly disconnection of the closed system. about the present study offers data on the epidemiology of UTI in the ICU, the identified risk factors, etiology, diagnosis, impact upon morbidity and mortality, and the measures to prevent its appearance.

Evaluation of nosocomial infections and risk factors in critically ill patients

Background

Nosocomial infections are one of the most serious complications in intensive care unit patients because they lead to high morbidity, mortality, length of stay and cost. The aim of this study was to determine the nosocomial infections, risk factors, pathogens and the antimicrobial susceptibilities of them in intensive care unit of a university hospital.

Material/Methods

The patients were observed prospectively by the unit-directed active surveillance method based on patient and the laboratory.

Results

20.1% of the patients developed a total of 40 intensive care unit-acquired infections for a total of 988 patient-days. The infection sites were the lower respiratory tract, urinary tract, bloodstream, wound, and the central nervous system. The respiratory deficiency, diabetes mellitus, usage of steroid and antibiotics were found as the risk factors. The most common pathogens were Enterobacteriaceae, Staphylococcus aureus, Candida species. No vancomycin resistance was determined in Gram positive bacteria. Imipenem and meropenem were found to be the most effective antibiotics to Enterobacteriaceae.

Conclusions

Hospital infection rate in intensive care unit is not very high. The diabetes mellitus, length of stay, usage of steroids, urinary catheter and central venous catheter were determined as the risk factors by the final logistic regression analysis. These data, which were collected from a newly established intensive care unit of a university hospital, are important in order to predict the infections and the antimicrobial resistance profile that will develop in the future.

Surveillance of catheter-associated urinary tract infection in 4 intensive care units at Alexandria university hospitals in Egypt

BACKGROUND

We sought to measure the incidence rate of catheter-associated urinary tract infections (CAUTIs), identify risk factors associated with acquiring the infections; and identify the etiologic and antibiotic resistant patterns associated with CAUTIs in the intensive care units (ICUs) of a large University Hospital in Alexandria, Egypt.

METHODS

Prospective active surveillance of CAUTIs was conducted in 4 ICUs during a 13-month period from January 1, 2007 through January 31, 2008 in Alexandria University Hospital using the standard Centers for Disease Control National Nosocomial Infection Surveillance (NNIS) case definitions. Rates were expressed as the number of infections per 1000 catheter days.

RESULTS

During the study period, 757 patients were monitored after ICU admission, with either existing indwelling urinary catheters (239), or got catheters inserted after ICU admission (518), for a total duration of 16301 patient days, and 10260 patient catheter days. A total of 161 episodes of infection were diagnosed, for an overall rate of 15.7 CAUTIs per 1000 catheter days. Important risk factors associated with acquiring CAUTI were female gender (Relative risk (RR), 1.7; 95% confidence interval (CI); 1.7-4.3), and previous catheterization within the same hospital admission (RR, 1.6; 95% CI; 1.3-1.96). Patients admitted to the chest unit, patients =40 years, patients with prolonged duration of catheterization, prolonged hospital and ICU stay had a significantly higher risk of acquiring CAUTIs. Out of 195 patients who had their urine cultured, 188 pathogens were identified for 161 infected patients; 96 (51%) were Candida, 63 (33.5%) gram negatives, 29 (15.4%) gram positives. The prevalence of ESBL producers among K. pneumoniae and E. coli isolates was 56% (14/25) and 78.6% (11/14), respectively.

CONCLUSION

Despite infection control policies and procedures, CAUTI rates remain a significant problem in Alexandria University hospital. Using the identified risk factors, tailored intervention strategies are now being implemented to reduce the rates of CAUTIs in these 4 ICUs.

Nosocomial infections and risk factors in intensive care unit of a university hospital in Turkey

The aim of this study was to determine the types nosocomial infections (NIs) and the risk factors for NIs in the central intensive care unit (ICU) of Trakya University Hospital. The patients admitted to the ICU were observed prospectively by the unit-directed active surveillance method based on patient and the laboratory over a 9-month-period. The samples of urine, blood, sputum or tracheal aspirate were taken from the patients on the first and the third days of their hospitalization in ICU; the patients were cultured routinely. Other samples were taken and cultured if there was suspicion of an infection. Infections were considered as ICU-associated if they developed after 48 hours of hospitalization in the unit and 5 days after discharge from the unit if the patients had been sent to a different ward in the hospital. The rate of NIs in 135 patients assigned was found to be 68%. The most common infection sites were lower respiratory tract, urinary tract, bloodstream, catheter site and surgical wound. Hospitalization in ICU for more than 6 days and colonization was found to be the main risk factor for NIs. Prolonged mechanical ventilation and tracheostomy, as well as frequently changed nasogastric catheterization, were found to be risk factors for lower respiratory tract infections. For bloodstream infections, both prolonged insertion of and frequent change of arterial catheters, and for urinary tract infections, female gender, period and repeating of urinary catheterization were risk factors. A high prevalence rate of nosocomial infections was found in this study. Invasive device use and duration of use continue to greatly influence the development of nosocomial infection in ICU. Important factors to prevent nosocomial infections are to avoid long hospitalization and unnecessary device application. Control and prevention strategies based on continuing education of healthcare workers will decrease the nosocomial infections in the intensive care unit.

Effectiveness of simple daily sensitization of physicians to the duration of central venous and urinary tract catheterization

PURPOSE

To evaluate the effectiveness of simple daily sensitization of physicians to the duration of central venous and urinary tract catheterization, and impact on infection rates.

METHODS

A prospective, before-after study in a surgical intensive care unit. All consecutive patients who had a central venous catheter (CVC) and/or urinary tract catheter (UTC) were included during two consecutive periods. Period 1 (August 2005 to May 2006) served as the control period. During Period 2 (July 2006 to April 2007), a red square, added to the patient's daily care sheet, questioned the physician about the utility of the CVC and/or UTC. If the response was "No", the CVC and/or the UTC were removed by a nurse.

RESULTS

A total of 1,271 patients were analyzed (Period 1, n = 676; Period 2, n = 595). The duration of catheterization (median [interquartile range]) was significantly reduced in Period 2 compared to Period 1 (from (5 [3-9] to 4 [3-7] days, p < 0.001, for CVC, and from 5 [3-11] to 4 [3-8] days, p < 0.001, for UTC). The incidence and density incidence of CVC infection decreased in Period 2 compared to Period 1 (from 1.8% to 0.3%, p = 0.010, and from 2.8 to 0.7/1,000 CVC-days, p = 0.051) whereas UTC infections were not significantly different (4.3 to 3.0%, p = 0.230, and 5.0 to 4.9/1,000 UTC-days, p = 0.938, respectively).

CONCLUSIONS

A simple daily reminder to physicians on the patients' care sheets decreased the duration of central venous and urinary tract catheterization, and tended to decrease CVC infection rate without affecting UTC infection.

Novel antiseptic urinary catheters for prevention of urinary tract infections: correlation of in vivo and in vitro test results

Urinary catheters are widely used for hospitalized patients and are often associated with high rates of urinary tract infection. We evaluated in vitro the antiadherence activity of a novel antiseptic Gendine-coated urinary catheter against several multidrug-resistant bacteria. Gendine-coated urinary catheters were compared to silver hydrogel-coated Foley catheters and uncoated catheters. Bacterial biofilm formation was assessed by quantitative culture and scanning electron microscopy. These data were further correlated to an in vivo rabbit model. We challenged 31 rabbits daily for 4 days by inoculating the urethral meatus with 1.0 x 10(9) CFU streptomycin-resistant Escherichia coli per day. In vitro, Gendine-coated urinary catheters reduced the CFU of all organisms tested for biofilm adherence compared with uncoated and silver hydrogel-coated catheters (P < 0.004). Scanning electron microscopy analysis showed that a thick biofilm overlaid the control catheter and the silver hydrogel-coated catheters but not the Gendine-coated urinary catheter. Similar results were found with the rabbit model. Bacteriuria was present in 60% of rabbits with uncoated catheters and 71% of those with silver hydrogel-coated catheters (P < 0.01) but not in those with Gendine-coated urinary catheters. No rabbits with Gendine-coated urinary catheters had invasive bladder infections. Histopathologic assessment revealed no differences in toxicity or staining. Gendine-coated urinary catheters were more efficacious in preventing catheter-associated colonization and urinary tract infections than were silver hydrogel-coated Foley catheters and uncoated catheters.

SMART approaches for reducing nosocomial infections in the ICU

Nosocomial infections are problematic in the ICU because of their frequency, morbidity, and mortality. The most common ICU infections are pneumonia, bloodstream infection, and urinary tract infection, most of which are device related. Surgical site infection is common in surgical ICUs, and Clostridium difficile-associated diarrhea is occurring with increasing frequency. Prospective observational studies confirm that use of evidence-based guidelines can reduce the rate of these ICU infections, especially when simple tactics are bundled. To increase the likelihood of success, follow the specific, measurable, achievable, relevant, and time bound (SMART) approach. Choose specific objectives that precisely define and quantify desired outcomes, such as reducing the nosocomial ICU infection rate of an institution by 25%. To measure the objective, monitor staff adherence to tactics and infection rates, and provide feedback to ICU staff. Make objectives achievable and relevant by engaging stakeholders in the selection of specific tactics and steps for implementation. Nurses and other stakeholders can best identify the tactics that are achievable within their busy ICUs. Unburden the bedside provider by taking advantage of new technologies that reduce nosocomial infection rates. Objectives should also be relevant to the institution so that administrators provide adequate staffing and other resources. Appoint a team to champion the intervention and collaborate with administrators and ICU staff. Provide ongoing communication to reinforce educational tactics and fine-tune practices over time. Make objectives time bound; set dates for collecting baseline and periodic data, and a completion date for evaluating the success of the intervention.

[Urinary tract infections in a postoperative recovery unit]

OBJECTIVE

To analyze the frequency, etiology, risk factors, and mortality relating to urinary tract infection (UTI) in a postoperative recovery unit.

MATERIALS AND METHODS

A prospective study was carried out from 1998 through 2003 of all patients who stayed longer than 48 hours in a 12-bed critical care unit and who were followed to 48 hours following discharge from the unit. A descriptive statistics were compiled and univariate and multiple variable Cox regression analyses were performed for episodes of nosocomial UTI.

RESULTS

The incidence density for UTI associated with bladder catheterization was 8.4 cases per 1000 patient-days. The pathogens most frequently isolated in patients with bacteriuria were Candida albicans and Escherichia coli. The pathogen most frequently isolated in UTI in trauma patients was E. coli, whereas C. albicans was most often found in the postoperative patients. Multivariable analysis identified 3 risk factors: degree of severity on admission, duration of catheterization, and presence of diabetes mellitus. The mortality risk in patients with bladder catheterization and UTI was 2.20.

CONCLUSIONS

UTIs can have serious consequences and are responsible for excess mortality. The real importance of UTI is unknown and is probably underestimated despite the publication of many studies. We found that the UTI microbiology findings were markedly different for the trauma and postoperative cohorts in our department.

Discordance between perception and treatment practices associated with intensive care unit-acquired bacteriuria and funguria: a Canadian physician survey

OBJECTIVE

To determine physician practice and perception about the management of intensive care unit (ICU)-acquired bacteriuria and funguria.

DESIGN

Cross-sectional, self-administered, Web-based survey.

SETTING

All provinces within Canada.

PARTICIPANTS

Staff ICU physicians who are members of either the Canadian Critical Care Trials Group or the Canadian Critical Care Society.

INTERVENTIONS

Survey items were developed by four ICU clinicians, and survey sensibility was assessed by five independent intensivists. Nonrespondents received three follow-up reminders. Participants were asked questions about general perceptions and practices regarding the management of ICU-acquired bacteriuria and funguria. Clinical scenarios were used to elicit management strategies, including antimicrobial prescriptions.

MEASUREMENTS AND MAIN RESULTS

Ninety of 198 physicians (45%) responded. Bacteriuria was perceived by 63% of the respondents to be a frequent but low-morbidity problem. Most intensivists (98%) did not use a protocol for management. Traditional symptoms were rarely used to interpret the significance of bacteriuria. Presence of systemic inflammatory response syndrome (93%), presence of hemodynamic changes (91%), and urinalysis (69%) were used often. Within clinical scenarios, source control via urinary catheter change was not universal, ranging from 44% to 67% in the various scenarios, even in patients presenting with septic shock. Prescription of antimicrobials was common across scenarios despite the low-morbidity perception. In an asymptomatic patient, 19% of respondents would prescribe antimicrobials. Changing the species from fungus to bacteria and the presence of systemic inflammatory response syndrome or shock increased the likelihood of antimicrobial use up to 70% to 80%.

CONCLUSIONS

ICU physicians perceive bacteriuria to have low morbidity. However, management approaches vary considerably, and systemic antimicrobials are frequently prescribed. Increased clinical instability and bacterial vs. fungal organisms isolated in urine cultures increased the use of antimicrobials. The considerable variability in practice and discordance between likelihood of urinary tract infection and antimicrobial prescription, highlights the need for additional clinical trials.

Strategies for the development of the urinary catheter

Indwelling urinary catheters are utilized in the management of a wide range of conditions both in an acute and a chronic setting. However, utilization of this type of device is associated with a number of issues, including an increased propensity to develop bacteriuria, symptomatic infection and also encrusted deposits on the device. The development of novel biomaterials, incorporation of therapeutic agents and other strategies to minimize the issues associated with these devices are discussed in this review.

A randomized trial of catheter change and short course of antibiotics for asymptomatic bacteriuria in catheterized ICU patients

OBJECTIVE

To determine the effect on the occurrence of urosepsis of a treatment with a short course of antibiotics and indwelling urethral catheter replacement in clinically asymptomatic intensive care unit (ICU) patients with a positive urine culture occurring at least 48 h after catheterization.

METHODS

A prospective randomized clinical trial was conducted in the medico-surgical ICU of a tertiary care centre. Sixty patients hospitalized in the ICU with an indwelling urethral catheter for longer than 48 h developing an asymptomatic positive urine culture were randomized to receive either a 3-day course of antibiotics associated with the replacement of the indwelling urethral catheter 4 h after first antibiotic administration or no antibiotics, no catheter replacement (standard of care).

RESULTS

Three patients in each group developed urosepsis (P=0.1). There were no significant differences in duration of mechanical ventilation between the study group and the standard of care group (9 [4-20] days vs 5 [2-15] days, P=0.2), in duration of urinary catheterization (22 [11-40] days vs 18 [14-33] days, P=0.8), or in length of ICU stay (28 [13-46] vs 19 [15-34], P=0.6). The recurrence of positive urine culture at days 7 and 15 was not affected by the randomization (P=0.1). The profile of bacterial resistance was similar in the two groups.

CONCLUSIONS

Treating a positive urine culture in an asymptomatic patient with an indwelling urethral catheter does not reduce the occurrence of urosepsis in the medico-surgical ICU.

Nosocomial infections in neurocritical care

Development of nosocomial infections is a commonly encountered problem for critically ill patients. Approximately half of all nosocomial pneumonias in the neurointensive care unit (NICU) are associated with ventilator-associated pneumonia. Prompt diagnosis with appropriate specimen analysis is required in order to prevent increased morbidity. Catheter-related blood stream infection imposes financial as well as medical implications. Multifaceted interventions are helpful to ensure adherence with evidence-based infection control guidelines. Urosepsis occurs in approximately 16% of patients. Colonized patients without evidence of infection do not require treatment, but the indwelling catheter should be changed. NICU patients have increased risk of developing cerebrospinal fluid infection due to frequent placement of external ventricular drains. The incidence of ventriculostomy-related meningitis or ventriculitis is approximately 8%. It is unclear whether the duration of ventricular catheter has any relationship with the risk of infection. Patients often receive multiple antibiotics, leading to an increased risk of developing Clostridium difficile colitis, which needs prompt diagnosis and appropriate antimicrobial therapy.

Correlation of urinalysis and dipstick results with catheter-associated urinary tract infections in surgical ICU patients

OBJECTIVE

To determine the utility of urinalysis and dipstick results in predicting urinary tract infections in catheterized ICU patients.

DESIGN AND SETTING

Urine samples were collected for 4months from patients admitted a ten-bed surgical ICU of an urban public teaching hospital designated by the state of New York as a level I trauma center. The correlation was analyzed between urinalysis and dipstick results from urine samples and subsequent quantitative culture results.

PATIENTS

All patients with indwelling urinary catheters admitted to the ICU were considered eligible; 106 patients were enrolled, and 300 individual urine samples were analyzed.

MEASUREMENTS AND RESULTS

There were 44 catheter-associated urinary tract infections. Nitrite presence was the best indicator of infection (91.8% specificity) but was not a reliable clinical test due to a sensitivity of 29.5% and positive and negative likelihood ratios of 3.52 and 0.56, respectively. None of the other parameters (leukocyte esterase, white blood cell count, urobilinogen, presence of yeast or bacteria) were independently correlated with the culture results either individually or in combination.

CONCLUSIONS

Based on our data we cannot recommend the use of urinalysis or dipstick in screening for potential catheter-associated urinary tract infections.

The transcriptional antiterminator RfaH represses biofilm formation in Escherichia coli

We investigated the influence of regulatory and pathogenicity island-associated factors (Hha, RpoS, LuxS, EvgA, RfaH, and tRNA5Leu) on biofilm formation by uropathogenic Escherichia coli (UPEC) strain 536. Only inactivation of rfaH, which encodes a transcriptional antiterminator, resulted in increased initial adhesion and biofilm formation by E. coli 536. rfaH inactivation in nonpathogenic E. coli K-12 isolate MG1655 resulted in the same phenotype. Transcriptome analysis of wild-type strain 536 and an rfaH mutant of this strain revealed that deletion of rfaH correlated with increased expression of flu orthologs. flu encodes antigen 43 (Ag43), which mediates autoaggregation and biofilm formation. We confirmed that deletion of rfaH leads to increased levels of flu and flu-like transcripts in E. coli K-12 and UPEC. Supporting the hypothesis that RfaH represses biofilm formation through reduction of the Ag43 level, the increased-biofilm phenotype of E. coli MG1655rfaH was reversed upon inactivation of flu. Deletion of the two flu orthologs, however, did not modify the behavior of mutant 536rfaH. Our results demonstrate that the strong initial adhesion and biofilm formation capacities of strain MG1655rfaH are mediated by both increased steady-state production of Ag43 and likely increased Ag43 presentation due to null rfaH-dependent lipopolysaccharide depletion. Although the roles of rfaH in the biofilm phenotype are different in UPEC strain 536 and K-12 strain MG1655, this study shows that RfaH, in addition to affecting the expression of bacterial virulence factors, also negatively controls expression and surface presentation of Ag43 and possibly another Ag43-independent factor(s) that mediates cell-cell interactions and biofilm formation.

Epidemiology of intensive care unit-acquired urinary tract infections

PURPOSE OF REVIEW

The development of urinary tract infections in critically ill adult patients is associated with considerable morbidity, prolonged hospitalization, and greater healthcare expenditures. We review the occurrence, microbiology, risk factors for acquisition, and outcomes associated with intensive care unit-acquired urinary tract infections.

RECENT FINDINGS

Reports from several countries indicate that nosocomial urinary tract infections frequently complicate the course of patients admitted to intensive care units. Virtually all patients who develop an intensive care unit-acquired urinary tract infection have indwelling urinary catheters; other factors associated with the development of these infections include increased duration of urinary catheterization, female sex, intensive care unit length of stay, and preceding systemic antimicrobial therapy. The most frequent pathogens include Escherichia coli, Pseudomonas aeruginosa, enterococci, and Candida albicans; both the species distribution and rates of resistance vary considerably among institutions and regions. Secondary bloodstream infections are uncommon. Although acquisition of an intensive care unit-acquired urinary tract infection has been associated with a prolongation of intensive care unit length of stay, higher cost, and a higher crude case fatality rate, they do not appear to independently increase the risk for death.

SUMMARY

Urinary tract infection is a common complication of critical illness that is associated with increased patient morbidity but not mortality. There is a relative paucity of research on nosocomial urinary tract infection specifically acquired in the intensive care unit and further studies are needed to better define the epidemiology and management of these infections.

Health-Care–Associated Infections and Prevention

Health-care-associated infections (HAIs) are an important cause of perioperative morbidity and mortality. Currently, one out of every 10 surgical patients develops an HAI. Causes of HAIs vary, but include the transient immunodeficiency associated with surgery,immobility, and the presence of indwelling devices. With rates of antimicrobial resistance increasing, prevention remains the best solution. The investigators review the most frequently encountered health-care-associated infections with an emphasis on preventative strategies. The article addresses issues related to the diagnosis,treatment, and prevention of health-care-related pneumonia,health-care-associated urinary tract infections, and intravascular-catheter-related infections. The article also discusses the utility of hand hygiene policies.

Nursing management of urinary tract infections for catheterized patients

Nosocomial urinary tract infections account for up to 40% of all hospital-acquired infections with 80% of these associated with the use of urinary catheters. The most important risk factor for infection is duration of catheterization. Clinical practices in catheter management vary widely and frequently are not evidence-based. It is vital that all indwelling catheters should be connected to a sterile closed urinary drainage system and that the connection between the catheter and the urinary drainage system is not broken except for good clinical reasons. Catheter care is a nursing procedure the importance of which is sometimes overlooked and cleansing of the perineum and meatus should be performed twice daily using soap and water.