Claudia Vallone Silva

Successful prevention of ventilator-associated pneumonia in an intensive care setting

BACKGROUND Ventilator-associated pneumonia (VAP) is one of the most common health care-associated infections (HAIs) in critical care settings. OBJECTIVE Our objective was to examine the effect of a series of interventions, implemented in 3 different periods to reduce the incidence of VAP in an intensive care unit (ICU). METHODS A quasiexperimental study was conducted in a medical-surgical ICU. Multiple interventions to optimize VAP prevention were performed during different phases. From March 2001 to December 2002 (phase 1: P1), some Centers for Disease Control and Prevention (CDC) evidence-based practices were implemented. From January 2003 to December 2006 (P2), we intervened in these processes at the same time that performance monitoring was occurring at the bedside, and, from January 2007 to September 2008 (P3), we continued P2 interventions and implemented the Institute for Healthcare Improvements ventilator bundle plus oral decontamination with chlorhexidine and continuous aspiration of subglottic secretions. RESULTS The incidence density of VAP in the ICU per 1000 patient-days was 16.4 in phase 1, 15.0 in phase 2, and 10.4 in phase 3, P=.05. Getting to zero VAP was possible only in P3 when compliance with all interventions exceeded 95%. CONCLUSION These results suggest that reducing VAP rates to zero is a complex process that involves multiple performance measures and interventions.

A hospital-based matched case-control study to identify clinical outcome and risk factors associated with carbapenem-resistant Klebsiella pneumoniae infection.

BackgroundHealthcare-associated infections caused by Klebsiella pneumoniae isolates are increasing and few effective antibiotics are currently available to treat patients. We observed decreased carbapenem susceptibility among K. pneumoniae isolated from patients at a tertiary private hospital that showed a phenotype compatible with carbapenemase production although this group of enzymes was not detected in any sample. The aim of this study was to describe the epidemiology and clinical outcomes associated with carbapenem-resistant K. pneumoniae and to determine the antimicrobial resistance mechanisms.MethodsRisk factors associated with carbapenem-resistant K. pneumoniae infections were investigated by a matched case–control study from January 2006 through August 2008. A cohort study was also performed to evaluate the association between carbapenem resistance and in-hospital mortality. Bacterial identification and antimicrobial susceptibility were determined by Vitek 2 and Etest. Carbapenemase activity was detected using spectrophotometric assays. Production of beta-lactamases and alterations in genes encoding K. pneumoniae outer membrane proteins, OmpK35 and OmpK36, were analyzed by PCR and DNA sequencing, as well as SDS-Page. Genetic relatedness of carbapenem resistant isolates was evaluated by Pulsed Field Gel Electrophoresis.ResultsSixty patients were included (20 cases and 40 controls) in the study. Mortality was higher for patients with carbapenem-resistant K. pneumoniae infections compared with those with carbapenem-susceptible K. pneumoniae (50.0% vs 25.7%). The length of central venous catheter use was independently associated with carbapenem resistance in the multivariable analysis. All strains, except one, carried blaCTX-M-2, an extended-spectrum betalactamase gene. In addition, a single isolate also possessed blaGES-1. Genes encoding plasmid-mediated AmpC beta-lactamases or carbapenemases (KPC, metallo-betalactamases or OXA-carbapenemases) were not detected.ConclusionsThe K. pneumoniae multidrug-resistant organisms were associated with significant mortality. The mechanisms associated with decreased K. pneumoniae carbapenem susceptibility were likely due to the presence of cephalosporinases coupled with porin alterations, which resulted from the presence of the insertion sequences in the outer membrane encoding genes.

Positive deviance: A program for sustained improvement in hand hygiene compliance

BACKGROUND There is a paucity of data evaluating whether positive deviance (PD) can sustain improvement in hand hygiene compliance. METHODS An observational study comparing the effect of PD on compliance with hand hygiene was conducted in two 20-bed step-down units (SDUs) at a private tertiary care hospital. In a 3-month baseline period (April-June 2008), hand hygiene counts were performed by electronic handwashing counters. Between July 1, 2008, and November 30, 2009, (East SDU) and between September 30, 2008, and December 2009 (West SDU), PD was applied in both units. RESULTS There was more than a 2-fold difference in the number of alcohol gel aliquots dispensed per month from April 2008 (before PD) to November 2009 (last month in PD) in the East SDU. There was also a 2-fold difference in the number of alcohol gel aliquots dispensed per month from September 2008 (before PD) to December 2009 (last month in PD) in the West SDU. The difference in the rate of health care‒associated infections (HAIs) between the baseline period and 2009 was statistically significant in the East SDU (5.8 vs 2.8 per 1,000 device-days; P = .008) and in the West SDU (3.7 vs 1.7 per 1,000 device-days; P = .023). CONCLUSIONS PD was responsible for a sustained improvement in hand hygiene in the inpatient setting and was associated with a decrease in the incidence of device-associated HAIs.

Risk factors for nosocomial infections in a critically ill pediatric population: a 25-month prospective cohort study.

We studied risk factors for nosocomial infections among 500 critically ill children who were admitted to a pediatric intensive care unit from August 1994 through August 1996 and who were prospectively followed until death, transfer, or discharge. Age, gender, postoperative state, length of stay, device-utilization ratio, pediatric risk of mortality score, and total parenteral nutrition were the risk factors studied. Through multivariate analysis, we identified three independent risk factors for nosocomial infection: device-utilization ratio (odds ratio [OR], 1.6; 95% confidence interval [CI95], 1.10-2.34), total parenteral nutrition (OR, 2.5; CI95, 1.05 5.81) and length of stay (OR, 1.7; CI95, 1.31-2.21).

Pseudo-outbreak of Pseudomonas aeruginosa and Serratia marcescens related to bronchoscopes

OBJECTIVE To investigate an apparent outbreak involving simultaneous isolation of Pseudomonas aeruginosa and Serratia marcescens from bronchoalveolar lavage (BAL) samples. DESIGN Retrospective and prospective cohort studies using chart review, environmental sampling, and ribotyping of all available isolates. Cleaning and disinfection procedures for the bronchoscopes were also evaluated. SETTING A 380-bed private hospital in São Paulo, Brazil PATIENTS Forty-one patients who underwent bronchoscopic procedures between December 1994 and October 1996 and from whom P. aeruginosa and S. marcescens were concomitantly isolated. Bronchoscopes and related items were microbiologically assessed. RESULTS P. aeruginosa and S. marcescens were simultaneously isolated from BAL samples 12.6% of the time (41 of 324) during the epidemic period versus 1.8% of the time (1 of 54) in the pre-epidemic period (P = .035). Ribotyping revealed two strains of P. aeruginosa and one of S. marcescens that were isolated from BAL samples of patients with no signs of respiratory tract infection, suggesting a pseudo-outbreak. Evaluation of bronchoscope disinfection revealed that inappropriate methods were being used. Implementation of simple control measures resulted in a significant decrease in simultaneous isolation of these species. CONCLUSION Prevention of pseudo-outbreaks requires meticulous use of preventive measures for infection-prone medical procedures.

Controlled Trial Measuring the Effect of a Feedback Intervention on Hand Hygiene Compliance in a Step-Down Unit

OBJECTIVE To evaluate hand hygiene compliance in 2 adult step-down units (SDUs). DESIGN A 6-month (from March to September 2007), controlled trial comparing 2 SDUs, one with a feedback intervention program (ie, the intervention unit) and one without (ie, the control unit). SETTING Two 20-bed SDUs at a tertiary care private hospital. METHODS Hand hygiene episodes were measured by electronic recording devices and periodic observational surveys. In the intervention unit, feedback was provided by the SDU nurse manager, who explained twice a week to the healthcare workers the goals and targets for the process measures. RESULTS A total of 117,579 hand hygiene episodes were recorded in the intervention unit, and a total of 110,718 were recorded in the control unit (P = .63). There was no significant difference in the amount of chlorhexidine used in the intervention and control units (34.0 vs 26.7 L per 1,000 patient-days; P = .36) or the amount of alcohol gel used (72.5 vs 70.7 L per 1,000 patient-days; P = .93). However, in both units, healthcare workers used alcohol gel more frequently than chlorhexidine (143.2 vs 60.7 L per 1,000 patient-days; P < .001). Nosocomial infection rates in the intervention and control units, respectively, were as follows: for bloodstream infection, 3.5 and 0.79 infections per 1,000 catheter-days (P = .18); for urinary tract infection, 15.8 and 15.7 infections per 1,000 catheter-days (P = .99); and for tracheostomy-associated pneumonia, 10.7 and 5.1 infections per 1,000 device-days (P = .13). There were no cases of infection with vancomycin-resistant enterococci and only a single case of infection with methicillin-resistant Staphylococcus aureus (in the control unit). CONCLUSIONS The feedback intervention regarding hand hygiene had no significant effect on the rate of compliance. Other measures must be used to increase and sustain the rate of hand hygiene compliance.

A program for sustained improvement in preventing ventilator associated pneumonia in an intensive care setting

BackgroundVentilator-associated pneumonia (VAP) is a common infection in the intensive care unit (ICU) and associated with a high mortality.MethodsA quasi-experimental study was conducted in a medical-surgical ICU. Multiple interventions to optimize VAP prevention were performed from October 2008 to December 2010. All of these processes, including the Institute for Healthcare Improvement’s (IHI) ventilator bundle plus oral decontamination with chlorhexidine and continuous aspiration of subglottic secretions (CASS), were adopted for patients undergoing mechanical ventilation.ResultsWe evaluated a total of 21,984 patient-days, and a total of 6,052 ventilator-days (ventilator utilization rate of 0.27). We found VAP rates of 1.3 and 2.0 per 1,000 ventilator days respectively in 2009 and 2010, achieving zero incidence of VAP several times during 12 months, whenever VAP bundle compliance was over 90%.ConclusionThese results suggest that it is possible to reduce VAP rates to near zero and sustain these rates, but it requires a complex process involving multiple performance measures and interventions that must be permanently monitored.

The effect of limiting antimicrobial therapy duration on antimicrobial resistance in the critical care setting.

BACKGROUND Using antimicrobial agents for prolonged periods of time and/or in heavy densities is known to contribute to antimicrobial resistance. METHODS A quasiexperimental, before and after study to limit the duration of antimicrobial therapy to 14 days was conducted in a medical-surgical intensive care unit (ICU). An intervention to optimize antimicrobial therapy was performed when antimicrobial agents had been prescribed for more than 14 days. We then compared antimicrobial utilization using the defined daily dose (DDD) per 1000 patient-days, as well as resistance rates in selected organisms in the intervention phase to the previous 10-month period. RESULTS In the intervention phase, doctors approved to discontinue the antimicrobial therapy before 14 days in 89.8% (415/462) of the prescribed antibiotics in the ICU. Comparing the 2 time periods, we found a reduction in carbapenems (24.5% decrease), vancomycin (14.3% decrease), and cephalosporins (12.2% decrease) in the intervention phase. Imipenem resistance decreased in Acinetobacter baumannii from 88.5% to 20.0% (P <or= .001) and in Klebsiella pneumoniae from 54.5% to 10.7% (P = .01). CONCLUSION These results suggest that an intervention to reduce the duration of antimicrobial therapy contributed to more rational use of antimicrobial agents and to the reduction of bacterial resistance in the critical care setting.

Preventing central venous catheter-associated primary bloodstream infections: characteristics of practices among hospitals participating in the Evaluation of Processes and Indicators in Infection Control (EPIC) study.

OBJECTIVES To describe the conceptual framework and methodology of the Evaluation of Processes and Indicators in Infection Control (EPIC) study and present results of CVC insertion characteristics and organizational practices for preventing BSIs. The goal of the EPIC study was to evaluate relationships among processes of care, organizational characteristics, and the outcome of BSI. DESIGN This was a multicenter prospective observational study of variation in hospital practices related to preventing CVC-associated BSIs. Process of care information (eg, barrier use during insertions and experience of the inserting practitioner) was collected for a random sample of approximately 5 CVC insertions per month per hospital during November 1998 to December 1999. Organization demographic and practice information (eg, surveillance activities and staff and ICU nurse staffing levels) was also collected. SETTING Medical, surgical, or medical-surgical ICUs from 55 hospitals (41 U.S. and 14 international sites). PARTICIPANTS Process information was obtained for 3,320 CVC insertions with an average of 58.2 (+/- 16.1) insertions per hospital. Fifty-four hospitals provided policy and practice information. RESULTS Staff spent an average of 13 hours per week in study ICU surveillance. Most patients received nontunneled, multiple lumen CVCs, of which fewer than 25% were coated with antimicrobial material. Regarding barriers, most clinicians wore masks (81.5%) and gowns (76.8%); 58.1% used large drapes. Few hospitals (18.1%) used an intravenous team to manage ICU CVCs. CONCLUSIONS Substantial variation exists in CVC insertion practice and BSI prevention activities. Understanding which practices have the greatest impact on BSI rates can help hospitals better target improvement interventions.

Secular trends of candidemia in a tertiary care hospital

BACKGROUND Candidemias account for 8% to 15% of hospital-acquired bloodstream infections. They have been associated with previous exposure to antimicrobials and are considered high-morbidity infections with high treatment costs. This study characterizes candidemias in a tertiary care hospital and assesses their incidence rates, clinical and microbiological features, and use of antifungals. METHODS We assessed hospital-acquired candidemias in the period from January 1997 to July 2007 in a high-complexity private hospital. RESULTS There were 151 cases of candidemia in 147 patients. The incidence rate was 0.74 episodes/1000 admissions. The mean age of the patients was 60 years (standard deviation +/- 24.9), and the mean length of hospital stay before the blood culture identified candidemia was 40.9 days (standard deviation +/- 86.3). The in-hospital mortality rate was 44.2%. C albicans was isolated in 44% (n = 67) of the cases, and no difference in mortality rates was found between species (Candida albicans vs C non-albicans, P = .6). The average use of antifungals in the period was 104.0 defined daily dose/1000 patient-days. CONCLUSION We found a high mortality rate associated to candidemia events and an increasingly important role of Candida non-albicans. New approaches to health care-related infection control and to defining prophylactic and preemptive therapies should change this scenario in the future.