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Biomedical subjects

Michael B Edmond

Publications and source records attributed to Michael B Edmond.

At least 19 recordsLinked to original sources
PubMed2007

Epidemiology of bloodstream infections in patients receiving long-term total parenteral nutrition.

GOALS: To describe the epidemiology and microbiologic characteristics of bloodstream infections (BSIs) in patients receiving long-term total parenteral nutrition (TPN). BACKGROUND: Home TPN therapy has been reported as a risk factor for BSI. However, little knowledge exists regarding the epidemiology of BSIs in this patient group. STUDY: A descriptive, observational epidemiologic study of patients receiving long-term TPN from January 1981 to July 2005 was performed. Variables analyzed include age, gender, time of follow-up, number of BSIs, microbiologic characteristics, underlying disease necessitating long-term TPN, catheter type, complications related to TPN, and clinical outcome. RESULTS: Forty-seven patients receiving long-term TPN were evaluated. The most frequent indication for long-term TPN was ischemic bowel disease (25.5%). The mean duration of follow-up was 4.5 years. Thirty-eight patients (80.9%) developed 248 BSIs while receiving TPN. More than 1 BSI episode occurred in 78.9% of these patients, and 23.8% of BSI episodes were polymicrobial. The most prevalent pathogen was coagulase negative staphylococci (33.5%). The most frequent complication among patients with BSI was central venous thrombosis (44.7%). Five patients were intravenous drug users. There were 11 deaths among the patients on long-term TPN, 4 of these were related to infection and 4 were related to intravenous drug use. CONCLUSIONS: The incidence of BSI is high, and a significant proportion of BSIs in long-term TPN patients are polymicrobial and due to multidrug-resistant bacteria and fungi. Careful management of the infusion line is required and interventions are needed to reduce the risk of catheter-related infections in this population.

Adolescent↗
PubMed2006

Systemic inflammatory response syndrome in adult patients with nosocomial bloodstream infections due to enterococci.

BACKGROUND: Enterococci are the third leading cause of nosocomial bloodstream infection (BSI). Vancomycin resistant enterococci are common and provide treatment challenges; however questions remain about VRE's pathogenicity and its direct clinical impact. This study analyzed the inflammatory response of Enterococcal BSI, contrasting infections from vancomycin-resistant and vancomycin-susceptible isolates. METHODS: We performed a historical cohort study on 50 adults with enterococcal BSI to evaluate the associated systemic inflammatory response syndrome (SIRS) and mortality. We examined SIRS scores 2 days prior through 14 days after the first positive blood culture. Vancomycin resistant (n = 17) and susceptible infections (n = 33) were compared. Variables significant in univariate analysis were entered into a logistic regression model to determine the affect on mortality. RESULTS: 60% of BSI were caused by E. faecalis and 34% by E. faecium. 34% of the isolates were vancomycin resistant. Mean APACHE II (A2) score on the day of BSI was 16. Appropriate antimicrobials were begun within 24 hours in 52%. Septic shock occurred in 62% and severe sepsis in an additional 18%. Incidence of organ failure was as follows: respiratory 42%, renal 48%, hematologic 44%, hepatic 26%. Crude mortality was 48%. Progression to septic shock was associated with death (OR 14.9, p < .001). There was no difference in A2 scores on days -2, -1 and 0 between the VRE and VSE groups. Maximal SIR (severe sepsis, septic shock or death) was seen on day 2 for VSE BSI vs. day 8 for VRE. No significant difference was noted in the incidence of organ failure, 7-day or overall mortality between the two groups. Univariate analysis revealed that AP2>18 at BSI onset, and respiratory, cardiovascular, renal, hematologic and hepatic failure were associated with death, but time to appropriate therapy >24 hours, age, and infection due to VRE were not. Multivariate analysis revealed that hematologic (OR 8.4, p = .025) and cardiovascular failure (OR 7.5, p = 032) independently predicted death. CONCLUSION: In patients with enterococcal BSI, (1) the incidence of septic shock and organ failure is high, (2) patients with VRE BSI are not more acutely ill prior to infection than those with VSE BSI, and (3) the development of hematologic or cardiovascular failure independently predicts death.

Adult↗
PubMed2006

Comparison of severity of illness scoring systems for patients with nosocomial bloodstream infection due to Pseudomonas aeruginosa.

BACKGROUND: Several acute illness severity scores have been proposed for evaluating patients on admission to intensive care units but these have not been compared for patients with nosocomial bloodstream infection (nBSI). We compared three severity of illness scoring systems for predicting mortality in patients with nBSI due to Pseudomonas aeruginosa. METHODS: We performed a historical cohort study on 63 adults in intensive care units with P. aeruginosa monomicrobial nBSI. RESULTS: The Acute Physiology, Age, Chronic Health Evaluation II (APACHE II), Sequential Organ Failure Assessment (SOFA), and Simplified Acute Physiologic Score (SAPS II), were calculated daily from 2 days prior through 2 days after the first positive blood culture. Calculation of the area under the receiver operating characteristic (ROC) curve confirmed that APACHE II and SAPS II at day -1 and SOFA at day +1 were better predictors of outcome than days -2, 0 and day 2 of BSI. By stepwise logistic regression analysis of these three scoring systems, SAPS II (OR: 13.03, CI95% 2.51-70.49) and APACHE II (OR: 12.51, CI95% 3.12-50.09) on day -1 were the best predictors for mortality. CONCLUSION: SAPS II and APACHE II are more accurate than the SOFA score for predicting mortality in this group of patients at day -1 of BSI.

APACHE↗
PubMed2006

Nosocomial bloodstream infections caused by Klebsiella pneumoniae: impact of extended-spectrum beta-lactamase (ESBL) production on clinical outcome in a hospital with high ESBL prevalence.

BACKGROUND: The frequency of ESBL producing Klebsiella pneumoniae bloodstream infections (BSI) is high in Brazilian hospitals, however little is known regarding what role, if any, resistance plays in the expected outcome in hospitals with a high prevalence of these pathogens. METHODS: From 1996 to 2001, hospital acquired K. pneumoniae BSI were evaluated retrospectively. Each patient was included only once at the time of BSI. ESBL producing strains were identified using the E-test method. The association of variables with the mortality related to bacteremia was included in a stepwise logistic regression model. RESULTS: One hundred and eight hospital acquired K. pneumoniae BSI met criteria for inclusion. Fifty two percent were due to ESBL producing strains. The overall in-hospital mortality was 40.8%. Variables independently predicting death by multivariate analysis were the following: mechanical ventilation (p = 0.001), number of comorbidities (p = 0.003), antimicrobials prescribed before bacteremia (p = 0.01) and fatal underlying disease (p = 0.025). CONCLUSION: Bacteremia due to ESBL producing K. pneumoniae strains was not an independent predictor for death in patients with BSI. An increased mortality in hospital-acquired BSI by K. pneumoniae was related to the requirement for mechanical ventilation, more than two comorbidities, the previous use of two or more antibiotics, and the presence of a rapidly fatal disease.

Adolescent↗
PubMed2006

Measurement and feedback of infection control process measures in the intensive care unit: Impact on compliance.

BACKGROUND: Infection control process measures provide actionable and measurable indicators for performance improvement. OBJECTIVE: To determine the relationship between the measurement and feedback of selected infection control process measures and compliance with infection control practices. METHODS: We measured selected infection control process measures (hand hygiene, femoral catheter use as a proportion of all central venous catheter (CVC) days and proportion of head of bed elevations) in the medical respiratory intensive care unit (ICU) (MRICU) and the surgical trauma ICU (STICU). All data were collected by trained infection control practitioners. Baseline data were obtained April through June 2004. Baseline hand hygiene data were obtained from May to June. Follow-up observations were obtained from July 2004 through March 2005. Both baseline and follow-up observations were reported to the units' leadership. The data were reviewed for improvement in compliance with process measures. Differences in proportions were analyzed for statistical significance by the chi(2) test. RESULTS: There was a statistically significant improvement in the head of bed elevation rates: 54.9% versus 98.4% (P < .001) for the MRICU and 46.5% versus 77.2% (P < .001) for the STICU, respectively. There was also a statistically significant decline in femoral catheter rates in both ICUs: 17.8% versus 10% (P = .001) in the MRICU and 8.4% versus 3% (P < .001) in the STICU, respectively. There was no significant improvement in hand hygiene rates in either ICU: 31.8% versus 39.3% (P = .1) in the MRICU and 50% versus 50.3% (P = .9) in the STICU, respectively. CONCLUSION: Feedback of process measures lowered the use of femoral catheters and improved the proportion of elevated head of beds in 2 ICUs, but there was no significant improvement in hand hygiene.

Catheterization, Central Venous↗
PubMed2006

Systemic inflammatory response syndrome in nosocomial bloodstream infections with Pseudomonas aeruginosa and Enterococcus Species: comparison of elderly and nonelderly patients.

OBJECTIVES: To determine whether the systemic inflammatory response syndrome (SIRS), clinical course, and outcome of monomicrobial nosocomial bloodstream infection (BSI) due to Pseudomonas aeruginosa or Enterococcus spp. is different in elderly patients than in younger patients. DESIGN: Historical cohort study. SETTING: An 820-bed tertiary care facility. PARTICIPANTS: One hundred twenty-seven adults with P. aeruginosa or enterococcal BSI. MEASUREMENTS: SIRS scores were determined 2 days before the first positive blood culture through 14 days afterwards. Elderly patients (> or =65, n=37) were compared with nonelderly patients (<65, n=90). Variables significant for predicting mortality in univariate analysis were entered into a logistic regression model. RESULTS: No difference in SIRS was detected between the two groups. No significant difference was noted in the incidence of organ failure, 7-day mortality, or overall mortality between the two groups. Univariate analysis revealed that Acute Physiology And Chronic Health Evaluation (APACHE) II score of 15 or greater at BSI onset; adjusted APACHE II score (points for age excluded) of 15 or greater at BSI onset; and respiratory, cardiovascular, renal, hematological, and hepatic failure were predictors of mortality. Age, sex, use of empirical antimicrobial therapy, and infection with imipenem-resistant P. aeruginosa or vancomycin-resistant enterococci did not predict mortality. Multivariate analysis revealed that hematological failure (odds ratio (OR)=8.1, 95% confidence interval (CI)=2.78-23.47), cardiovascular failure (OR=4.7, 95% CI=1.69-13.10), and adjusted APACHE II > or = 15 at BSI onset (OR=3.1, 95% CI=1.12-8.81) independently predicted death. CONCLUSION: Elderly patients did not differ from nonelderly patients with respect to severity of illness before or at the time of BSI. Elderly patients with pseudomonal or enterococcal BSIs did not have a greater mortality than nonelderly patients.

Age Factors↗
PubMed2006

Time to blood culture positivity as a predictor of clinical outcome of Staphylococcus aureus bloodstream infection.

Few studies have assessed the time to blood culture positivity as a predictor of clinical outcome in bloodstream infections (BSIs). The purpose of this study was to evaluate the time to positivity (TTP) of blood cultures in patients with Staphylococcus aureus BSIs and to assess its impact on clinical outcome. We performed a historical cohort study with 91 adult patients with S. aureus BSIs. TTP was defined as the time between the start of incubation and the time that the automated alert signal indicating growth in the culture bottle sounded. Patients with BSIs and TTPs of culture of </=12 h (n = 44) and >12 h (n = 47) were compared. Septic shock occurred in 13.6% of patients with TTPs of </=12 h and in 8.5% of patients with TTP of >12 h (P = 0.51). A central venous catheter source was more common with a BSI TTP of </=12 h (P = 0.010). Univariate analysis revealed that a Charlson score of >/=3, the failure of at least one organ (respiratory, cardiovascular, renal, hematologic, or hepatic), infection with methicillin-resistant S. aureus, and TTPs of </=12 h were associated with death. Age, gender, an APACHE II score of >/=20 at BSI onset, inadequate empirical antibiotic therapy, hospital-acquired bacteremia, and endocarditis were not associated with mortality. Multivariate analysis revealed that independent predictors of hospital mortality were a Charlson score of >/=3 (odds ratio [OR], 14.4; 95% confidence interval [CI], 2.24 to 92.55), infection with methicillin-resistant S. aureus (OR, 9.3; 95% CI, 1.45 to 59.23), and TTPs of </=12 h (OR, 6.9; 95% CI, 1.07 to 44.66). In this historical cohort study of BSIs due to S. aureus, a TTP of </=12 h was a predictor of the clinical outcome.

Adult↗
PubMed2005

Comparison of the systemic inflammatory response syndrome between monomicrobial and polymicrobial Pseudomonas aeruginosa nosocomial bloodstream infections.

BACKGROUND: Some studies of nosocomial bloodstream infection (nBSI) have demonstrated a higher mortality for polymicrobial bacteremia when compared to monomicrobial nBSI. The purpose of this study was to compare differences in systemic inflammatory response and mortality between monomicrobial and polymicrobial nBSI with Pseudomonas aeruginosa. METHODS: We performed a historical cohort study on 98 adults with P. aeruginosa (Pa) nBSI. SIRS scores were determined 2 days prior to the first positive blood culture through 14 days afterwards. Monomicrobial (n = 77) and polymicrobial BSIs (n = 21) were compared. RESULTS: 78.6% of BSIs were caused by monomicrobial P. aeruginosa infection (MPa) and 21.4% by polymicrobial P. aeruginosa infection (PPa). Median APACHE II score on the day of BSI was 22 for MPa and 23 for PPa BSIs. Septic shock occurred in 33.3% of PPa and in 39.0% of MPa (p = 0.64). Progression to septic shock was associated with death more frequently in PPa (OR 38.5, CI95 2.9-508.5) than MPa (OR 4.5, CI95 1.7-12.1). Maximal SIR (severe sepsis, septic shock or death) was seen on day 0 for PPa BSI vs. day 1 for MPa. No significant difference was noted in the incidence of organ failure, 7-day or overall mortality between the two groups. Univariate analysis revealed that APACHE II score > or = 20 at BSI onset, Charlson weighted comorbidity index > or = 3, burn injury and respiratory, cardiovascular, renal and hematologic failure were associated with death, while age, malignant disease, diabetes mellitus, hepatic failure, gastrointestinal complications, inappropriate antimicrobial therapy, infection with imipenem resistant P. aeruginosa and polymicrobial nBSI were not. Multivariate analysis revealed that hematologic failure (p < 0.001) and APACHE II score > or = 20 at BSI onset (p = 0.005) independently predicted death. CONCLUSION: In this historical cohort study of nBSI with P. aeruginosa, the incidence of septic shock and organ failure was high in both groups. Additionally, patients with PPa BSI were not more acutely ill, as judged by APACHE II score prior to blood culture positivity than those with MPa BSI. Using multivariable logistic regression analysis, the development of hematologic failure and APACHE II score > or = 20 at BSI onset were independent predictors of death; however, PPa BSI was not.

APACHE↗
PubMed2005

Systemic inflammatory response syndrome in adult patients with nosocomial bloodstream infection due to Pseudomonas aeruginosa.

OBJECTIVES: To evaluate relationships between the inflammatory response, clinical course, and outcome of nosocomial BSI due to Pseudomonas aeruginosa. METHODS: We performed a historical cohort study on 77 adults with P. aeruginosa (Pa) nBSI to define the associated systemic inflammatory response syndrome (SIRS). We examined SIRS scores 2 days prior through 14 days after the first positive blood culture. Imipenem resistant--IRPa (n=20) and susceptible infections--ISPa (n=57) were compared. Variables significant in univariate analysis were entered into a logistic regression model. RESULTS: Seventy-four percent of BSI were ISPa and 26.0% by IRPa. Septic shock occurred in 39.0%. Crude mortality was 48.1%. There was no difference in APACHE II (AP2) scores on days -2, -1 and 0 between the ISPa and IRPa groups. Multivariate analysis revealed that AP2> or =20 at BSI onset (P<0.001) and hematologic failure (P=0.001) independently predicted death. CONCLUSIONS: In patients with P. aeruginosa nBSI, the incidence of septic shock and organ failure is high; patients with IRPa BSI are not more acutely ill prior to infection than those with ISPa BSI and outcome is not significantly different; AP2> or =20 at BSI onset and the development of hematologic failure are independent predictors of death.

Adult↗
PubMed2005

Endocarditis due to vancomycin-resistant enterococci: case report and review of the literature.

BACKGROUND: Endocarditis due to vancomycin-resistant enterococci (VRE) is rare, and the literature consists almost exclusively of reports of single cases. METHODS: We report a case of VRE prosthetic valve endocarditis and review 18 cases of native and prosthetic valve VRE endocarditis reported in the literature. RESULTS: The majority of cases were due to Enterococcus faecium. Nearly all of these infections were hospital acquired, and the vast majority of patients had significant underlying disease processes, including dialysis and transplantation. More than three-quarters of cases were left-sided, and the aortic valve was most commonly involved. Peripheral stigmata of endocarditis were not reported in any of the cases. Approximately 40% of patients developed cardiac complications. Nearly three-quarters of patients survived, despite the difficulties associated with providing bactericidal antimicrobial therapy, and only 4 patients underwent valve replacement. CONCLUSIONS: VRE endocarditis is an uncommon nosocomial infection that affects patients with significant comorbid conditions. Most cases are due to E. faecium, and the aortic valve is involved in at least one-half of cases. One-third of patients require surgical treatment. Optimal antimicrobial therapy remains undefined, but an attempt to identify bactericidal combination therapy should be sought.

Adult↗
PubMed2005

Hospital and community fluoroquinolone use and resistance in Staphylococcus aureus and Escherichia coli in 17 US hospitals.

BACKGROUND: Fluoroquinolones are widely prescribed in hospitals and the community. Previous studies have shown associations between fluoroquinolone use and isolation of fluoroquinolone-resistant Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA). We performed an ecologic-level study to determine whether variability in hospital percentages of fluoroquinolone-resistant E. coli and MRSA were associated with fluoroquinolone use in hospitals and their surrounding communities. METHODS: We measured fluoroquinolone use in 17 US hospitals and their surrounding communities in the year 2000. Data on fluoroquinolone use in hospitals was electronically extracted from billing data. Data on fluoroquinolone use in communities was obtained from IMS health data for all prescriptions filled in pharmacies within a 16-km radius of each hospital. We used hospital antibiograms to determine the percentage of isolates that were fluoroquinolone-resistant E. coli and MRSA, and we performed linear regression to determine the relationship between percentage of resistant isolates and fluoroquinolone use in hospitals and their surrounding communities. RESULTS: There was a significant association between total fluoroquinolone use within hospitals and percentage of S. aureus isolates that were MRSA (r=0.77; P=.0003) and between total fluoroquinolone use in the community and percentage of E. coli isolates that were fluoroquinolone-resistant E. coli (r=0.68; P=.003). Population density within the 16-km radius also correlated with MRSA percentage (r=0.57; P=.015) and fluoroquinolone-resistant E. coli percentage (r=0.85; P=.002), but associations between total fluoroquinolone use and resistance remained significant after adjustment for population density. CONCLUSIONS: In this ecologic analysis, we found associations between fluoroquinolone use in hospitals and methicillin resistance in S. aureus and between fluoroquinolone use in communities and fluoroquinolone resistance in E. coli in hospitals. Antimicrobial use in hospitals and communities may have different relative importance with regard to resistance in different pathogens encountered in hospitals.

Anti-Bacterial Agents↗
PubMed2005

A statewide survey of nosocomial infection surveillance in acute care hospitals.

Increasingly, states are considering mandating the reporting of nosocomial infection data. To determine the impact of potential legislation, a questionnaire was mailed to the infection control department of each hospital in Virginia to assess the size of the infection control workforce and methodologies used for nosocomial infection surveillance. Most hospitals (64%) had 1 ICP full-time equivalent (FTE), and, at 86% of hospitals, the ICPs had other major responsibilities. The estimated mean additional ICP FTE required to perform hospital-wide surveillance was 1.7. Statewide, an additional 160 ICPs at an estimated annual cost of 11.5 million dollars would be required if reporting of all nosocomial infections were mandated.

Cross Infection↗
PubMed2005

Pseudomonas aeruginosa, Staphylococcus aureus, and fluoroquinolone use.

Few long-term multicenter investigations have evaluated the relationships between aggregate antimicrobial drug use in hospitals and bacterial resistance. We measured fluoroquinolone use from 1999 through 2003 in a network of US hospitals. The percentages of fluoroquinolone-resistant Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) were obtained from yearly antibiograms at each hospital. Univariate linear regression showed significant associations between a hospital's volume of fluoroquinolone use and percent resistance in most individual study years (1999-2001 for P. aeruginosa, 1999-2002 for S. aureus). When the method of generalized estimating equations was used, a population-averaged longitudinal model incorporating total fluoroquinolone use and the previous year's resistance (to account for autocorrelation) did not show a significant effect of fluoroquinolone use on percent resistance for most drug-organism combinations, except for the relationship between levofloxacin use and percent MRSA. The ecologic relationship between fluoroquinolone use and resistance is complex and requires further study.

Cross Infection↗