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Biomedical subjects

C Chenoweth

Publications and source records attributed to C Chenoweth.

17 recordsLinked to original sources
PubMed2001

Risk factors for anaerobic bloodstream infections in bone marrow transplant recipients.

The incidence of anaerobic bloodstream infections (BSI) in patients who underwent bone marrow transplantation (BMT) recently increased at our institution. A retrospective case-control study of patients undergoing BMT from January 1995 through December 1998 was performed to determine the microbiological characteristics, epidemiology, and outcome of anaerobic BSI and to identify independent risk factors for infection. Anaerobic BSI occurred in 23 patients, for a rate of 4 BSIs per 100 BMT procedures, and it accounted for 17% of all BSIs that occurred during the study period. Infection occurred at a mean (+/- standard deviation) of 7+/-4 days after BMT and 7+/-5 days after the onset of neutropenia. Fusobacterium nucleatum was the most frequently isolated pathogen (in 17 patients), followed by Leptotrichia buccalis (in 4), Clostridium septicum (in 1), and Clostridium tertium (in 1). Two case patients (9%) died. Severity of mucositis was an independent predictor of anaerobic BSI (odds ratio, 4.4; P=.01). Controlling mucositis is critical for the prevention of anaerobic BSI in this patient population.

Adult↗
PubMed2001

Electronic chart review as an aid to postdischarge surgical site surveillance: increased case finding.

BACKGROUND: At the University of Michigan Hospitals and Health Centers, there is increasing use of an electronic medical record. Because orthopedic surgeons dictate all outpatient visits to the patient's electronic record, total knee arthroplasties were chosen to determine whether the use of electronic medical records increased case finding. METHODS: All patients who underwent a total knee arthroplasty during the study period (1996-1999) were followed prospectively with the use of the National Nosocomial Infection Surveillance System definitions. Traditional surveillance methods were used to ascertain infections. In addition, each patient's postdischarge outpatient clinic chart was reviewed electronically for 1 year after operation. RESULTS: From 1996 to 1999, 555 procedures were performed. Overall, 25 infections were identified after operation. Seven infections were identified through traditional surveillance methods, which resulted in an average surgical site infection rate of 1.3%. The use of electronic chart review surveillance after discharge revealed a rate of 4.5%, which was significantly higher than traditional surveillance (P <.01). Eighteen of 25 infections (72%) would not have been identified with the use of traditional surveillance methods. CONCLUSION: Postdischarge electronic chart review enhanced case finding significantly, which resulted in a more accurate infection rate. Awareness should be given to the institutions' surveillance methods and intensity when comparing to published rates.

Arthroplasty, Replacement, Knee↗
PubMed2001

The role of economic evaluation in infection control.

Given the rise in health care-related expenditures, decision-makers are increasingly relying on both clinical effectiveness and economic efficiency when making health care decisions. The field of infection control is not immune to this rise in cost-consciousness among health care managers. This article clarifies the role of economic evaluation within infection control for both the user and producer of economic evaluations in this field. The strengths and drawbacks of the several different types of economic analysis--cost minimization, cost-effectiveness, cost-benefit, and cost utility analysis--will be discussed. Additionally, the important features of two specific methods used for economic evaluation-decision analytic modeling and economic analysis alongside a clinical trial-will be outlined. Finally, the criteria by which economic analyses should be judged will be provided. As economic evaluation and health services research continue to play an increasingly important role in health care, it will be vital for infection control advocates to partner with individuals from diverse fields to give decision-makers the type of information they need to make choices.

Clinical Trials as Topic↗
PubMed2001

An outbreak of coagulase-negative staphylococcal surgical-site infections following aortic valve replacement.

OBJECTIVES: To determine the cause of a coagulase-negative staphylococcal outbreak and to identify risk factors for surgical-site infections among patients following Medtronic Freestyle bioprosthesis implantation. DESIGN: Retrospective case-control study. SETTING: An 800-bed university referral center. PATIENTS: The cohort of 64 patients undergoing Freestyle valve replacement from September 1998 to December 1998. RESULTS: Seven patients developed infection (10.9% vs 1.1% during the preceding 8 months), including two with mediastinitis and five with endocarditis. There were no statistically significant differences between cases and controls with respect to age, gender, weight, underlying illness, preoperative hospital stay, duration of surgery, time on bypass, central venous catheter duration, National Nosocomial Infection Surveillance risk index, New York Heart Association class, albumin, or antibiotic prophylaxis. However, only three cases were documented to have received vancomycin prophylaxis. Of all staff evaluated, only surgical resident A was significantly associated with infection (odds ratio, 7.68; 95% confidence interval, 1.3-44.1; P=.02) Pulsed-field gel electrophoresis patterns on Staphylococcus epidermidis isolates from four of the six cases were identical. These cases were performed on different days. Surgical resident Awas the only staff member present in the operating room for all cases caused by the epidemic strain. This S epidermidis strain, however, was not isolated from operating room staff. CONCLUSION: A surgical resident was significantly associated with infection. However, the cause of this outbreak was likely multifactorial. Changes occurring during the investigation included institution of vancomycin as routine prophylaxis and modification of surgical technique, which contributed to the resolution of the outbreak.

Aortic Valve↗
PubMed2000

The potential clinical and economic benefits of silver alloy urinary catheters in preventing urinary tract infection.

BACKGROUND: Catheter-associated urinary tract infection (UTI) is associated with increased morbidity, mortality, and costs. A recent meta-analysis concluded that silver alloy catheters reduce the incidence of UTI by 3-fold; however, clinicians must decide whether the efficacy of such catheters is worth the extra per unit cost of $5.30. OBJECTIVE: To assess the clinical and economic impact of using silver alloy urinary catheters in hospitalized patients. METHODS: The decision model, performed from the health care payer's perspective, evaluated a simulated cohort of 1000 hospitalized patients on general medical, surgical, urologic, and intensive care services requiring short-term urethral catheterization (2-10 days). We compared 2 catheterization strategies: silver alloy catheters and standard (noncoated) urinary catheters. Outcomes included the incidence of symptomatic UTI and bacteremia and direct medical costs. RESULTS: In the base-case analysis, use of silver-coated catheters led to a 47% relative decrease in the incidence of symptomatic UTI from 30 to 16 cases per 1000 patients (number needed to treat = 74) and a 44% relative decrease in the incidence of bacteremia from 4.5 to 2.5 cases per 1000 patients (number needed to treat = 500) compared with standard catheters. Use of silver alloy catheters resulted in estimated cost savings of $4.09 per patient compared with standard catheter use ($20.87 vs $16.78). In a multivariate sensitivity analysis using Monte Carlo simulation, silver-coated catheters provided clinical benefits over standard catheters in all cases and cost savings in 84% of cases. CONCLUSIONS: Using silver alloy catheters in hospitalized patients requiring short-term urinary catheterization reduces the incidence of symptomatic UTI and bacteremia, and is likely to produce cost savings compared with standard catheters.

Alloys↗
PubMed2000

Four year prospective evaluation of nosocomial bacteremia: epidemiology, microbiology, and patient outcome.

A prospective study of all patients with clinically significant nosocomial bacteremia at one institution from 1994 to 1997 was performed to: (1) describe the epidemiology and microbiology of nosocomial bacteremias; (2) determine the crude mortality associated with such infections; and (3) identify independent predictors of mortality. Four hundred four episodes of bacteremia occurred in 322 patients; the crude in-hospital mortality was 31%. Coagulase-negative staphylococci, Staphylococcus aureus, and enterococci were the leading pathogens, and intravascular catheters were the most frequently identified source. The highest mortality occurred in patients with candidemia (67%). Independent predictors of mortality included evidence of shock at the time of infection, acquisition of bacteremia in an intensive care unit, a "Do Not Attempt Resuscitation" order, and the presence of certain comorbid conditions (e.g., malignancy, HIV infection). Because many of these infections may be preventable, education of health care providers and strict adherence to established infection control practices are critical.

Adult↗
PubMed1999

Antimicrobial resistance in community-acquired respiratory tract pathogens.

Antimicrobial resistance among common respiratory pathogens has become a significant problem. However, there remain multiple treatment options, including the newer macrolides, third-generation cephalosporins, beta-lactam/beta-lactamase inhibitor antibiotics, and the newer fluoroquinolones.

Community-Acquired Infections↗
PubMed1999

The attributable mortality and costs of primary nosocomial bloodstream infections in the intensive care unit.

Primary nosocomial bloodstream infection (BSI) is a common occurrence in the intensive care unit (ICU) and is associated with a crude mortality of 31.5 to 82.4%. However, an accurate estimate of the attributable mortality has been limited because of confounding by severity of illness. We undertook this study to assess the attributable mortality and costs associated with an episode of BSI. Infected patients were defined as those who had an episode of BSI during the study period. Uninfected control subjects were matched to the infected patients based upon a number of factors, including predicted mortality on the day prior to infection. The main outcome measures were crude ICU mortality, length of stay, and costs. We found no difference in the crude mortality for the infected and the uninfected patients (35.3 and 30.9%, respectively, p = 0.51). However, among survivors, the patients with nosocomial bloodstream infections did have excess length of stay (mean, 10 d; median, 5 d; p = 0.007) and increased direct costs (mean difference, $34,508; p = 0.008). After matching for severity of illness, we could not detect an association between primary nosocomial bloodstream infections and increased ICU mortality. We did find that primary nosocomial bloodstream infections increased ICU length of stay and costs.

Case-Control Studies↗
PubMed1998

A survey of infection control professional staffing patterns at University HealthSystem Consortium institutions.

BACKGROUND: Proper staffing of infection control departments has long been a topic of interest. The most complete report on the subject, the Study on the Efficacy of Nosocomial Infection Control, was published in 1985. To provide current benchmarking comparison data for expected staff reductions at the University of Michigan Health System, a survey of University HealthSystem Consortium members was performed. METHODS: A survey tool was developed to obtain general demographic, staffing, and case-mix information. An infection control professional at each institution was contacted to obtain most of the information. Additional information was obtained from standard references. RESULTS: Responses were obtained from 45 University HealthSystem Consortium members (67%). Full-time equivalent ratios were based on the following parameters and compared for the institutions: number of occupied beds (according to occupancy rate, median 137 occupied beds/full-time equivalent), number of intensive care unit beds (median 28 beds/full-time equivalent), number of admissions or discharges (median 6686 admissions/full-time equivalent), number of ambulatory care visits (median 104,426 visits/full-time equivalent), and case-mix index (median 1.75). CONCLUSIONS: Many institutions are using benchmarking comparison data to make decisions regarding staff reductions. This survey provides preliminary data for determining the "best practice" in staffing for infection control departments. More information may be needed to evaluate other factors that affect infection control professionals' workload.

Academic Medical Centers↗
PubMed1998

Risk factors for candidemia in a children's hospital.

Candida species are increasingly important nosocomial pathogens in critically ill children. A 2.3-fold increase in the rate of nosocomial candidemia at our 200-bed tertiary care children's hospital prompted a study to identify risk factors for this infection. Twenty-six cases were identified between 1992 and 1993, representing 21% of all nosocomial bloodstream infections. Candida albicans was the most frequent isolate (58%), followed by Candida parapsilosis (27%). A case-control study revealed that there was a statistically significant association between the occurrence of candidemia and placement of a central venous catheter in the femoral vein (P = .03), the use of a tunneled central venous catheter (P = .05), and prolonged hyperalimentation (P = .04). Patients with candidemia also were noted to have candiduria more often than controls (P = .003) and were more likely to have had topical antifungal agents prescribed (P = .04). Multivariate analysis showed that hyperalimentation was an independent risk factor for the development of candidemia. We conclude that measures must be taken to reduce these risk factors whenever possible.

Adolescent↗
PubMed1997

The stethoscope. A potential source of nosocomial infection?

BACKGROUND: Stethoscope diaphragms have been shown to harbor potentially pathogenic bacteria. OBJECTIVES: To assess bacterial contamination on the diaphragm and under the plastic rim that secures the diaphragm of stethoscopes of physicians, nurses, medical students, and house staff in an intensive care unit and a general medical ward of a large university hospital. Also to compare the effectiveness of various cleaning agents and assess the transmissibility of bacteria from contaminated stethoscopes to human skin. METHODS: Aerobic and anaerobic bacterial cultures were performed on 40 randomly selected stethoscopes. We compared the effects of isopropyl alcohol, sodium hypochlorite (bleach), and benzalkonium chloride swabs, as well as soap and water, on reducing bacterial contamination on the stethoscope diaphragm and under the rim. The transmissibility of Micrococcus luteus inoculated onto a stethoscope diaphragm to clean human skin was also determined. RESULTS: Eleven genera and species of bacteria were isolated, with coagulase-negative staphylococcus present on 100% of stethoscopes and Staphylococcus aureus on 38%. Clostridium difficile was not isolated. The mean (+/-SE) number of total colony-forming units was 158 +/- 33 per diaphragm and 289 +/- 54 per rim. Physicians' stethoscope diaphragms had significantly more colony-forming units of coagulase-negative staphylococci than those of nurses: 163 +/- 44 vs 50 +/- 12, respectively (P = .02). The most effective cleaning agent was isopropyl alcohol after cleaning the diaphragm surface, the stethoscope diaphragms contained 0.2 +/- 0.2 colony-forming units and the rims contained 2.2 +/- 1.5 colony-forming units (P = .01). In addition, M luteus was transferred from inoculated stethoscopes to human skin. CONCLUSIONS: Most stethoscopes harbor potential pathogens but are not a source of C difficile. Physicians' stethoscopes generally had a higher bacterial load than nurses' stethoscopes. Isopropyl alcohol is an effective cleaning agent when applied to the stethoscope diaphragm. Stethoscopes transfer M luteus to human skin, making it likely that other bacteria can be transferred as well.

Cross Infection↗
PubMed1997

Antimicrobial resistance: implications for managing respiratory failure.

The prevalence of antibiotic resistance in respiratory pathogens is increasing rapidly. In the community, resistance to beta-lactam antibiotics has escalated dramatically among Moraxella catarrhalis, Haemophilus influenzae, and Streptococcus pneumoniae. Resistance to penicillin among S. pneumoniae has developed at an alarming rate over the past two decades. Recent studies in the United States have cited rates of penicillin resistance as high as 23.6%, with 9.5% exhibiting high-level resistance. Many of these strains are resistant to multiple antibiotics. Antimicrobial resistance in hospital-acquired pathogens is a problem, which in large part reflects patterns of antibiotic use. Antimicrobial resistance may arise via multiple mechanisms. Pseudomonas aeruginosa and other gram-negative bacilli have become increasingly resistant to beta-lactam antibiotics, including imipenem. Extended-spectrum beta-lactamases are seen with increasing frequency in Enterobacteriaceae, primarily Klebsiella spp. Fluoroquinolone resistance has increased in P. aeruginosa and Staphylococcus aureus and has now been identified in Escherichia coli isolated from hematology wards. Excessive use of antibiotics may promote the emergence and spread of resistant microorganisms. Rigorous infection control measures and modification of antibiotic use patterns may limit or reduce the prevalence of resistant organisms.

Bacteria↗
PubMed1995

Comparison of case-finding methodologies for endometritis after cesarean section.

BACKGROUND: Endometritis is a possible complication of delivery among patients undergoing cesarean section, resulting in increased costs and patient morbidity. However, traditional case-finding methods for endometritis may not identify most cases. We compared various case-finding methods with a reference method to determine a simple and accurate method for collecting data on endometritis after cesarean section. METHODS: We reviewed charts of all patients undergoing cesarean section (N = 167) during March 1 through July 31, 1991. These data were compared with study case-finding methods that used microbiology data, infection report forms from nursing, and computerized reports linking patients undergoing cesarean section with intravenous antibiotic use data and admission and discharge diagnoses. RESULTS: Each case-finding method was compared separately with the reference method ("gold standard"), which was designed to capture all cases among the patients in the study population (N = 145). This review yielded nine cases of endometritis (infection rate of 5.4/100 procedures). The computerized report method linking patients who underwent cesarean section with antibiotic use had a positive predictive value of 0.53. Methods that used microbiology data and nursing report forms had lower positive predictive values of 0.18 and 0.20, respectively. CONCLUSIONS: In our institution, case finding for postcesarean endometritis by means of a computerized report linking patients undergoing cesarean section with i.v. antibiotic use data and admission and discharge diagnoses is the most effective method of detecting postcesarean endometritis. It also represents the most efficient use of the infection control department's resources.

Anti-Bacterial Agents↗
PubMed1990

The epidemiology of enterococci.

The enterococci are emerging as a significant cause of nosocomial infections, accounting for approximately 10% of hospital acquired infections. They are found as normal inhabitants of the human gastrointestinal tract, but may also colonize the oropharynx, vagina, perineal region and soft tissue wounds of asymptomatic patients. Until recently, evidence indicated that most enterococcal infections arose from patients' own endogenous flora. Recent studies, however, suggest that exogenous acquisition may occur and that person-to-person spread, probably on the hands of medical personnel, may be a significant mode of transmission of resistant enterococci within the hospital. The use of broad-spectrum antibiotics, especially cephalosporins, is another major factor in the increasing incidence of enterococcal infections. These findings suggest that barrier precautions, as applied with other resistant nosocomial pathogens, along with more judicial use of antibiotics may be beneficial in preventing nosocomial spread of resistant enterococci.

Cross Infection↗
PubMedDate not supplied

Four-year prospective evaluation of community-acquired bacteremia: epidemiology, microbiology, and patient outcome.

The objectives of this study were to (1) describe the epidemiology and microbiology of community-acquired bacteremia; (2) determine the crude mortality associated with such infections; and (3) identify independent predictors of mortality. All patients with clinically significant community-acquired bacteremia admitted to a university-affiliated Veterans Affairs medical center from January 1994 through December 1997 were evaluated. During the study period, 387 bacteremic episodes occurred in 334 patients. Staphylococcus aureus, Escherichia coli, and coagulase-negative staphylococci were the most commonly isolated organisms; the most frequent sources were the urinary tract and intravascular catheters. Approximately 14% of patients died. Patient characteristics independently associated with increased mortality included shock (OR 3.7, p = 0.02) and renal failure (OR 4.0, p = 0.003). The risk of death was also higher in those whose source was pneumonia (OR 6.3, p = 0.03) or an intra-abdominal site (OR 10.7, p = 0.02), or if multiple sources were identified (OR 13.4, p = 0.003). Community-acquired bacteremia is often device-related and may be preventable. Strategies that have been successful in preventing nosocomial device-related bacteremia should be adapted to the outpatient setting.

Adult↗