Nosocomial infection in Auckland Healthcare hospitals

AIM: To determine the prevalence of nosocomial infection in Auckland Healthcare hospitals. BACKGROUND: Nosocomial infections cause patient morbidity and prolong hospital stay. Reporting surveillance results to staff has been shown to reduce nosocomial infection rates. METHOD: Point prevalence study for all patients in Auckland, Green Lane and National Women's hospitals. Standard definitions for nosocomial infections were used. RESULTS: One hundred and ten (12%) of 932 patients had 129 nosocomial infections: 27 (20%) surgical site infections; 25 (19%) lower respiratory tract infections; 23 (18%) skin/ soft tissue infections; 19 (15%) urinary tract infections; 14 (11%) bloodstream infections; and 21 (17%) other infections. Predominant organisms were: Staphylococcus aureus (29%), Escherichia coli (21%), other gram negative bacilli (14%), Pseudomonas aeruginosa (6%), streptococci (6%) and Candida albicans (6%). The prevalence of nosocomial infection was lower in National Women's Hospital (5%) than either Green Lane or Auckland hospitals (15% and 14% respectively), p < 0.01. The prevalence of nosocomial infection was the same in medical and surgical patients, 53 of 394 (14%) and 42 of 297 (14%), respectively. The highest prevalence was in intensive care unit patients, 7 of 31 (23%). The prevalence of nosocomial infection increased with patient age, 17-50 yr (8%) vs > 50 yr (14%), p < 0.01, and duration of hospitalisation 2% for < 2 days, 6% for 2-7 days vs 22% for > 7 days, p < 0.01. Risk factors for nosocomial infection were present in many patients: 339 (36%) had intravenous catheters in place; 268 (29%) patients had undergone surgery during their current admission; 122 (13%) had urinary catheters in place; and 122 (13%) had other invasive devices in situ. CONCLUSION: Our results are comparable with hospitals of similar size overseas. This study provides a base line for future studies which will enable the monitoring of trends over time and the impact of focused infection control initiatives.     

Epidemiology of nosocomial infections

The frequency of nosocomial infections lies between 5 and 10%, and varies according to the type of hospital and service. Age, underlying disease invasive devices (such as catheters) or procedures are the main risk factors. Common nosocomial infections are urinary tract infections, pneumonia, surgical site infections, bacteremia/septicemia and intravascular catheter-related infections. Gram positive cocci and gram negative bacilli account for one third and two thirds of microorganisms respectively, Staphylococcus aureus being frequently resistant to antibiotics. Prevention is based on a better control of infection risk related to the use of invasive devices.     

Nosocomial infections in HIV-infected patients: preliminary results from a multicenter surveillance system (1989-1995)

OBJECTIVE: To describe the characteristics of and trends in nosocomial infection among human immunodeficiency virus (HIV)-infected patients. DESIGN: Multicenter prospective cohort study. SETTING/PATIENTS: HIV-infected patients were enrolled at time of first inpatient admission at five Veterans' Administration Medical Centers (VAMCs). RESULTS: As of March 1995, 2,541 patients with 6,625 inpatient admissions had been monitored in the five VAMCs. A total of 530 nosocomial infections were detected using standard Centers for Disease Control and Prevention definitions. Overall distribution by infection site was 31% for primary bloodstream infections (BSIs), 28% for urinary tract infections, 15% for pneumonia, and 26% for all other sites. Of BSIs, 63% were central line-associated bloodstream infections (CLABs). The rate of CLABs per 1,000 central line days was 6.5 (range, 2.3-8.3) for all patients from participating hospitals, similar to the median CLAB rate of 6.0 for patients in medical intensive-care units (ICUs) of National Nosocomial Infections Surveillance (NNIS) System hospitals from January 1990 through September 1994. For ICU-specific CLABs, the rate from hospitals reporting at least one ICU CLAB was 12.7 (range, 12.1-13.1), comparable to the 90th percentile of NNIS hospital medical ICUs (13.1). Staphylococcus aureus, associated with 35% of BSIs, was the most common nosocomial BSI pathogen. Our data demonstrated the following: 13 (10%) of 134 patients with CD4 counts > or = 200 cells/mm3 had a CLAB, compared with 61 (6%) of 1,011 patients with CD4 counts < 200 cells/mm3, P = .08; the per-day risk of CLABs did not change with increased duration of catheterization (P = .4); and the per-day risk of a temporary (ie, short-term) CLAB was greater than that of a permanent CLAB (P < .001). CONCLUSIONS: The data suggest that HIV-infected patients were at higher risk of acquiring a BSI than were patients in the NNIS population; patients with CD4 counts > or = 200 cell/mm3 and temporary central lines were at increased risk for BSI, perhaps reflecting widespread prophylaxis with trimethoprim-sulfamethoxazole among patients with CD4 counts < 200 cells/mm3, and, in contrast to most studies, S aureus, not coagulase-negative Staphylococcus, was the most common BSI pathogen.     

Association of secondary and polymicrobial nosocomial bloodstream infections with higher mortality

The objective of this study was to characterize microbiological factors independently associated with higher mortality rates following nosocomial bloodstream infection. All patients admitted to the University of Iowa Hospitals and Clinics between 1 July 1989 and 30 June 1990 who developed a nosocomial bloodstream infection were included. The crude in-house mortality for the 364 patients with nosocomial bloodstream infections was 33%. These deaths accounted for 25% of all in-hospital deaths. Significant risk factors for death from bloodstream infection included diagnoses of cancers and diseases of the cardiovascular and respiratory systems (p < 0.01). Neither previous surgery nor neutropenia was associated with higher mortality rates. Whereas the crude mortality rates associated with gram-negative (33%) and gram-positive (31%) bloodstream infections were similar, that associated with fungemia was higher (54%, p < 0.02). The mortality associated with secondary bloodstream infections (46%) was higher than that associated with primary bloodstream infections (28%, p < 0.001). Furthermore, polymicrobial infections had a worse prognosis than infections from which a single pathogen was isolated (p < 0.05). A multivariate, logistic regression model identified four variables that independently predicted mortality (p = 0.025): age (OR 1.01 per year; CI95 1.00-1.02); cancer (OR 2.35, CI95 1.26-4.37) or diseases of the cardiovascular or respiratory systems (OR 2.20, CI95 1.04-4.67); polymicrobial infection (OR 2.34; CI95 1.21-4.53); and secondary bloodstream infection (OR 2.46; CI95 1.50-4.02). The last variable was the strongest independent predictor. Our study demonstrates the importance of microbiological factors in the outcome of nosocomial bloodstream infections.     

The influence of tobacco parental smoking on serum IgE level of their offspring

During a period of twelve years (1984-1995), ninety-seven pediatric patients experienced 107 nosocomial fungal infections at Mackay Memorial Hospital. The nosocomial fungal infection rate in pediatric patients was lower than that of the hospital as whole, but it increased significantly. The average rate in the last three years (1993-1995) was 1.20 per thousand discharged patients, 10 times that of the first three years (1984-1986). Two-thirds of the patients were below one year of age. Half of the infections occurred in Intensive Care Units. The bloodstream was the most common site of infection (40.2%), followed by the urinary tract and skin. Important underlying diseases included malignancies, prematurity, and congenital anomalies. Common risk procedures included total parenteral nutrition (43.3%), endotracheal intubation (29.9%), central venous catheterization (25.8%), operation (14.4%). Near 90% of the patients had previously received antibiotics. Candida albicans was responsible for 58.1% of the infections. Thirty-three patients expired, of whom 18 died of the fungal infections. With the trend of increasing nosocomial fungal infections, physicians should be more alert to the possibility of such infections.     

Decreased hypotensive responsiveness to nitric oxide donor S-nitroso N-acetyl-DL-penicillamine (SNAP) in spontaneously hypertensive (SHR) rats

The nosocomial infection (NI) rate in German hospitals was studied in order to create reference data for comparison in hospitals where ongoing surveillance is impossible. The study was designed as a one-day prevalence study. Patients in 72 selected hospitals (inclusion criteria: acute care hospitals with departments for general medicine, surgery, obstetrics/gynaecology) were examined by four external investigators (physicians trained and validated in the diagnosis of NI). A total of 14,996 patients were studied. The overall prevalence rate was 3.5% (CI 3.1-3.9) with a variation of 0-8.9% between hospitals. The commonest NI were: urinary tract infection (42.1%), lower respiratory tract infection (20.6%), surgical site infections (15.8%) and primary sepsis (8.3%). The highest prevalence rate (15.3%) was found in intensive care ward patients, followed by surgery (3.8%), general medicine (3.0%) and gynaecology/obstetrics (1.4%). The infection rate varied significantly with hospital size. A microbiology laboratory report was only available for 56.5% of patients thought to have an NI, and there were remarkable differences between hospitals with and without an on-site microbiology laboratory. Because of this and other methodological reasons the NI prevalence rates reported here may represent the absolute minimum of nosocomially infected patients in Germany.     

Spiral CT vs incremental CT: is spiral CT superior in imaging of the brain?

Historically, staphylococci, pseudomonads, and Escherichia coli have been the nosocomial infection troika; nosocomial pneumonia, surgical wound infections, and vascular access-related bacteremia have caused the most illness and death in hospitalized patients; and intensive care units have been the epicenters of antibiotic resistance. Acquired antimicrobial resistance is the major problem, and vancomycin-resistant Staphylococcus aureus is the pathogen of greatest concern. The shift to outpatient care is leaving the most vulnerable patients in hospitals. Aging of our population and increasingly aggressive medical and surgical interventions, including implanted foreign bodies, organ transplantations, and xenotransplantation, create a cohort of particularly susceptible persons. Renovation of aging hospitals increases risk of airborne fungal and other infections. To prevent and control these emerging nosocomial infections, we need to increase national surveillance, "risk adjust" infection rates so that interhospital comparisons are valid, develop more noninvasive infection-resistant devices, and work with health-care workers on better implementation of existing control measures such as hand washing.     

Microbiological factors influencing the outcome of nosocomial bloodstream infections: a 6-year validated, population-based model

All patients (n = 1,745) with nosocomial bloodstream infection identified between 1986 and 1991 at a single 900-bed tertiary care hospital were studied to identify microbiological factors independently associated with mortality due to the infection. Patients were identified by prospective, case-based surveillance and positive blood cultures. Mortality rates were examined for secular trends. Prognostic factors were determined with use of univariate and multivariate analyses, and both derivation and validation sets were used. A total of 1,745 patients developed nosocomial bloodstream infection. The 28-day crude mortality was 22%, and crude in-hospital mortality was 35%. Factors independently (all P < .05) associated with increased 28-day mortality rates were older age, longer length of hospital stay before bloodstream infection, and a diagnosis of cancer or disease of the digestive system. After adjustment for major confounders, Candida species were the only organisms independently influencing the outcome of nosocomial bloodstream infection (odds ratio [OR] for mortality = 1.84; 95% confidence interval [CI], 1.22-2.76; P = .0035). The two additional microbiological factors independently associated with increased mortality were pneumonia as a source of secondary infection (OR = 2.74; 95% CI, 1.87-4.00; P < .0001) and polymicrobial infection (OR = 1.68; 95% CI, 1.22-2.32; P = .0014). Our data suggest that microbiological factors independently affect the outcome of nosocomial bloodstream infection.     

Interleukin-6 and acute-phase protein concentrations in surgical intensive care unit patients: diagnostic signs in nosocomial infection

OBJECTIVE: To determine the value of serum concentrations of interleukin-6 (IL-6), C-reactive protein, and glycosylation of alpha 1-acid glycoprotein as tools for diagnosing nosocomial infection in surgical intensive care unit (ICU) patients. DESIGN: Prospective, consecutive entry study of patients with an anticipated stay of at least 24 hrs in a surgical ICU. SETTING: University hospital, a major provider of acute surgical care. PATIENTS: One hundred four consecutive patients admitted to the surgical ICU between March and June 1990. MEASUREMENTS: Concentrations of IL-6, C-reactive protein, and glycosylation of alpha 1-acid glycoprotein were measured on days 1 and 6 after ICU admission. Clinical evaluation for infection was performed daily in a blinded fashion, i.e., without knowing the results of the acute-phase parameters. MAIN RESULTS: On day 6 after surgery or trauma, nosocomial infection could be ascertained in 13 cases. The clinical parameter of fever > 38 degrees C had a sensitivity of 54% and a specificity of 90% to demonstrate nosocomial infection. Infected patients showed increased concentrations of IL-6 (p < .001), C-reactive protein (p < .001), and increased reactivity of alpha 1-acid glycoprotein to concanavalin A (p < .001) compared with patients without infections. By choosing appropriate cutoff values, IL-6 determinations had the highest specificity (97%), and C-reactive protein values had the highest sensitivity (85%) for diagnosing nosocomial infections. In uninfected patients, 81% of the IL-6 values, but only 29% of the C-reactive protein values, were back to the normal range on day 6 after injury. CONCLUSION: Due to the rapid normalization after trauma, a single measurement of the serum IL-6 concentration may be useful to support or refute the clinical suspicion of nosocomial infection.     

Quantifying changes in retinal circulation: the generation of parametric images from fluorescein angiograms

Critical care unit patients show a higher risk of developing a bloodstream infection than ward patients. The urinary tract is the main source of hospital-acquired secondary bloodstream infection. Nosocomial urinary tract infection is promoted by bladder catheterization in the vast majority of cases. Aerobic gram-negative bacilli are the prevalent agents of bloodstream infection secondary to a nosocomial urinary tract infection. Sepsis and septic shock are severe complications of these infections in the critical care patient. Management of patients with a septic process of urinary source calls for the combination of adequate life-supporting care, an appropriate antibiotic therapy, and innovative adjunctive measures. Accurate catheter care is the best measure to adopt for the prevention of urosepsis.     

Hepatectomy including more than half of liver volume with intermittent portal triad occlusion

The main results of the bloodstream infection (BSI) component of the Belgian National Programme for the Surveillance of Hospital Infections (NSIH project) are reported. From October 1992 to September 1996, 117 hospitals (59.1% of Belgian acute-care institutions) reported 13678 nosocomial BSIs. The incidence was 7.05 BSI episodes per 10000 patient-days. The incidence of BSI increased with hospital size and over time. Bloodstream infections were secondary to an infectious body site in 40.3% of the episodes, catheter-related in 23.5%, and of unknown origin in 36.2%. The associated in-hospital mortality was 31.4% and was highest in BSIs secondary to a respiratory tract infection (49.3%). In intensive care units, the incidence of BSI was 38.5 per 10000 patient-days. Coagulase-negative staphylococci were the most prevalent microorganisms (22%), followed by Staphylococcus aureus (14.1%) and Escherichia coli (13.5%). In catheter-related BSIs, these proportions were 41.9%, 18.8%, and 2.3%, respectively. The proportion of polymicrobial episodes was 9.9%. Methicillin resistance in Staphylococcus aureus was 22.3%. With its high participation rate, the NSIH project has characterized the epidemiology of nosocomial BSIs in Belgium during the period studied.     

Nosocomial infections in Germany. Their epidemiology in old and new Federal L?nder

OBJECTIVE: To determine the prevalence rate of nosocomial infections in different parts of Germany. PATIENTS AND METHODS: The study involved 14,966 patients (45.9% medical, 35.9% surgical, 14.7% obstetrical/gynaecological and 3.5% intensive care) in 72 randomly chosen German hospitals (59 in the old [i.e. previously West German] and 13 in the new [i.e. East German] Federal Lands). Using the CDC criteria for the diagnosis of nosocomial infections specially trained doctors determined whether the infection was in fact nosocomial. RESULTS: There was a 3.5% prevalence rate of nosocomial infections in the entire population (95% confidence interval 3.1-3.9%). In view of the chosen methods and the in part incorrect indication of microbiological diagnosis in the included hospital, this rate of nosocomial infection is likely to be a minimum number. The prevalence rate for the most important nosocomial infections was lower in the new Lands of Federal Germany than the older ones (total prevalence of 2.7 vs 3.6%). The difference is mainly due to the less frequent employment of various devices (e.g. peripheral vascular catheters), rather than different hygienic standards in their use. CONCLUSION: The lower prevalence rate of nosocomial infections in the new Lands, because fewer devices are employed, underlines the need constantly to test the indications for their use.     

Comparison of toxicity induced by HT-2 toxin on human and rat granulo-monocytic progenitors with an in vitro model

Catheter-associated bloodstream infections remain an important cause of nosocomial infection, with an estimated 50,000-100,000 cases occurring each year in the United States. Central venous catheters are believed to be responsible for 90% of such infections. The cumulative risk of acquiring a catheter-related bloodstream infection has ranged between 1 and 10% for central venous catheters in general and 6% for total parenteral nutrition catheters. The skin is the most common source of organisms causing catheter-related infections. Recent prospective studies have shown that the incidence density per catheter day does not increase with duration of catheterization and that routine changes, either over a guidewire or by new site puncture, do not appear to lower the risk of infection. Diagnosis of infection can be difficult in intensive care patients but is usually easier in less ill patients with a central venous catheter. Quantitative or semiquantitative laboratory techniques can be used to confirm the diagnosis in the appropriate clinical setting. A variety of preventive measures have been shown to minimize the risk of development of catheter-related bloodstream infection, including use of maximal aseptic technique for insertion, use of special teams for care of the catheter, limiting manipulation of the catheter, use of povidone-iodine ointment and cotton gauze dressings for recently inserted catheters, a silver-impregnated collagen cuff and antiseptic-impregnated catheters.     

Role of glutathione S-transferase GSTM1, GSTM3, GSTP1 and GSTT1 genotypes in modulating susceptibility to smoking-related lung cancer

The prevalence and risk factors for nosocomial lower respiratory tract infections (LRTI) in Germany were determined as part of a national survey on nosocomial infections. The study included 14,966 patients in 72 representatively selected hospitals with departments of general medicine, surgery, obstetrics, gynecology, and intensive care units (ICU). Surveillance was carried out by four previously validated medical doctors who strictly applied the CDC-criteria for diagnosis of nosocomial infections. The overall prevalence of hospital-acquired LRTI was 0.72% with the highest rate in hospitals with more than 600 beds (1.08%) and among the patients on intensive care units (9.00%). Ventilator-associated pneumonia rates were highest in patients on ICUs (13.27). Polytrauma, impaired consciousness, chronic airway disease, prior surgery, and cardiovascular disease were significantly related to the occurrence of nosocomial LRTI. P. aeruginosa was the predominant organism causing nosocomial LRTI. Nosocomial LRTI remain a problem mainly on ICUs. Patients at risk should be monitored with extra care.     

Experience with two validation methods in a prevalence survey on nosocomial infections

OBJECTIVE: To determine whether an investigator effect remained on the first German study on the prevalence of nosocomial infections Nosokomiale Infektionen in Deutschland Erfassung und Pr?vention (NIDEP), despite extensive validation efforts. DESIGN: Two validation methods were applied: bedside validation and validation by case studies. In both cases, the results of the four investigators were compared with the diagnosis of gold standard observers. SETTING: Validation measures were applied before, intermittently, during, and at the end of the surveillance period in 72 acute-care hospitals with 14,966 patients. RESULTS: The overall sensitivity in the bedside-validation periods was 89.0%; the overall specificity was 99.5%. For validation by case studies, overall sensitivity was 95.6%, and overall specificity was 92.8%. At the end of the surveillance, a remarkable investigator effect was found. CONCLUSION: Despite validation results that were assessed as satisfactory, based on available literature, an investigator effect was observed. This underlines the need for data validation and the formulation of recommendations for data validation. Clarification of the Centers for Disease Control and Prevention criteria for pneumonia and primary bloodstream infection and the inclusion of some diagnostic test results may reduce or prevent an investigator effect in future studies.     

A regional evaluation of variation in low-severity hospital admissions

OBJECTIVE: Determine patient and hospital-level variation in proportions of low-severity admissions. DESIGN: Retrospective cohort study. SETTING: Thirty hospitals in a large metropolitan region. PATIENTS: A total of 43,209 consecutive eligible patients discharged in 1991 through 1993 with congestive heart failure (n = 25,213) or pneumonia (n = 17,995). MEASUREMENTS AND MAIN RESULTS: Admission severity of illness was measured from validated multivariable models that estimated the risk of in-hospital death; models were based on clinical data abstracted from patients' medical records. Admissions were categorized as "low severity" if the predicted risk of death was less than 1%. Nearly 15% of patients (n = 6,382) were categorized as low-severity admissions. Compared with other patients, low-severity admissions were more likely (p < .001) to be nonwhite and to have Medicaid or be uninsured. Low-severity admissions had shorter median length of stay (4 vs 7 days; p < .001), but accounted for 10% of the total number of hospital days. For congestive heart failure, proportions of low-severity admissions across hospitals ranged from 10% to 25%; 12 hospitals had rates that were significantly different (p < .01) than the overall rate of 17%. For pneumonia, proportions ranged from 3% to 22%; 12 hospitals had rates different from the overall rate of 12%. Variation across hospitals remained after adjusting for patient sociodemographic factors. CONCLUSIONS: Rates of low-severity admissions for congestive heart failure and pneumonia varied across hospitals and were higher among nonwhite and poorly insured patients. Although the current study does not identify causes of this variability, possible explanations include differences in access to ambulatory services, decisions to admit patients for clinical indications unrelated to the risk of hospital mortality, and variability in admission practices of individual physicians and hospitals. The development of protocols for ambulatory management of low-severity patients and improvement of access to outpatient care would most likely decrease the utilization of more costly hospital services.     

The impact of nosocomial infections on patient outcomes following cardiac surgery

STUDY OBJECTIVE: To evaluate the relationship between nosocomial infections and clinical outcomes following cardiac surgery, and to identify risk factors for the development of nosocomial infections in this patient population. DESIGN: Prospective cohort study. SETTING: Barnes-Jewish Hospital, St. Louis, a university-affiliated teaching hospital. PATIENTS: Six hundred five consecutive patients undergoing cardiac surgery. INTERVENTIONS: Prospective patient surveillance and data collection. MAIN OUTCOME MEASURES: Occurrence of nosocomial infections, multiorgan dysfunction, hospital mortality, and risk factors for the acquisition of nosocomial infections. RESULTS: One hundred thirty-one (21.7%) patients acquired at least one nosocomial infection following cardiac surgery. Four independent risk factors for the development of a nosocomial infection were identified: the duration of mechanical ventilation, postoperative empiric antibiotic administration, the duration of urinary tract catheterization, and female gender. Thirty (5.0%) patients died during their hospitalization. The mortality rate of patients acquiring a nosocomial infection (11.5%) was significantly greater than the mortality rate of patients without a nosocomial infection (3.2%) (odds ratio [OR]=4.0; 95% confidence interval [CI]=2.7 to 5.8; p<0.001). Multiorgan dysfunction was found to be the most important independent determinant of hospital mortality (adjusted OR=23.8; 95% CI=13.5 to 42.1; p<0.001) along with the aortic cross-clamp time (adjusted OR=2.3; 95% CI=1.7 to 3.0; p=0.002) and severity of illness as measured by APACHE II (acute physiology and chronic health evaluation) (adjusted OR=1.1; 95% CI=1.1 to 1.2; p=0.019). Ventilator-associated pneumonia, clinical sepsis, female gender, the cardiopulmonary bypass time, and severity of illness were identified as independent risk factors for the development of multiorgan dysfunction. Among hospital survivors, patients acquiring a nosocomial infection had longer hospital lengths of stay compared to patients without a nosocomial infection (20.1+/-13.0 days vs 9.7+/-4.5 days; p<0.001). CONCLUSIONS: Nosocomial infections, which are common following cardiac surgery, are associated with prolonged lengths of hospitalization, the development of multiorgan dysfunction, and increased hospital mortality. These data suggest potential interventions for the prevention of nosocomial infections following cardiac surgery that could substantially improve patient outcomes and decrease medical care costs.     

Trends in antifungal use and epidemiology of nosocomial yeast infections in a university hospital

This report describes both the trends in antifungal use and the epidemiology of nosocomial yeast infections at the University of Iowa Hospitals and Clinics between fiscal year (FY) 1987-1988 and FY 1993-1994. Data were gathered retrospectively from patients' medical records and from computerized databases maintained by the Pharmacy, the Program of Hospital Epidemiology, and the Medical Records Department. After fluconazole was introduced, use of ketoconazole decreased dramatically but adjusted use of amphotericin B decreased only moderately. However, the proportion of patients receiving antifungal therapy who were treated with amphotericin B declined markedly. In FY 1993-1994, 26 patients of the gastrointestinal surgery service received fluconazole. Among these patients, fluconazole use was prophylactic in 16 (61%), empiric in 3 (12%), and directed to a documented fungal infection in 7 (27%). Rates of nosocomial yeast infection in the adult bone marrow transplant unit increased from 6.77/1,000 patient days in FY 1987-1988 to 10.18 in FY 1989-1990 and then decreased to 0 in FY 1992-1993. Rates of yeast infections increased threefold in the medical and surgical intensive care units, reaching rates in FY 1993-1994 of 6.95 and 5.25/1,000 patient days, respectively. The rate of bloodstream infections increased from 0.044/1,000 patient days to 0.098, and the incidence of catheter-related urinary tract infections increased from 0.23/1,000 patient days to 0.68. Although the proportion of infections caused by yeast species other than Candida albicans did not increase consistently, C. glabrata became an important nosocomial pathogen.     

Analytical and biologic variability in measures of hemostasis, fibrinolysis, and inflammation: assessment and implications for epidemiology

CONTEXT: Central venous catheters impregnated with chlorhexidine and silver sulfadiazine have recently been introduced for the prevention of catheter-related infections. However, there remains some uncertainty regarding the efficacy of these catheters because of conflicting reports in the literature. OBJECTIVE: To evaluate the efficacy of chlorhexidine-silver sulfadiazine-impregnated central venous catheters in the prevention of catheter-related bloodstream infection. DATA SOURCES: Studies identified from a computerized search of the MEDLINE database from January 1966 to January 1998, reference lists of identified articles, and queries of principal investigators and the catheter manufacturer. STUDY SELECTION: Randomized trials comparing chlorhexidine-silver sulfadiazine-impregnated central venous catheters with nonimpregnated catheters were included. The outcomes assessed were catheter colonization and catheter-related bloodstream infection confirmed by catheter culture. DATA EXTRACTION: Twelve studies met the inclusion criteria for catheter colonization and included a total of 2611 catheters. Eleven studies with a total of 2603 catheters met the inclusion criteria for catheter-related bloodstream infection. Most patients in these studies were from groups considered to be at high risk for catheter-related infections. Summary statistics were calculated using Mantel-Haenszel methods under a fixed-effects model. DATA SYNTHESIS: The summary odds ratio for catheter colonization was 0.44 (95% confidence interval [CI], 0.36-0.54; P<.001), indicating a significant decrease in catheter colonization associated with impregnated catheters. The studies examining the outcome of primary interest, catheter-related bloodstream infection, had a summary odds ratio of 0.56 (95% CI, 0.37-0.84; P = .005). CONCLUSIONS: Central venous catheters impregnated with a combination of chlorhexidine and silver sulfadiazine appear to be effective in reducing the incidence of both catheter colonization and catheter-related bloodstream infection in patients at high risk for catheter-related infections.