Initial vancomycin dosing recommendations for critically ill patients undergoing continuous venovenous hemodialysis

BACKGROUND

Delaying appropriate antimicrobial therapy for critically ill patients increases the risk of death. Currently, there are insufficient data to guide initial vancomycin dosing for patients undergoing continuous venovenous hemodialysis (CVVHD).

OBJECTIVE

To develop practical recommendations for initial dosing of vancomycin, based on the pharmacokinetics of this drug in critically ill patients undergoing CVVHD.

METHODS

A chart review was conducted for 24 critically ill adult patients who had undergone concurrent CVVHD and vancomycin therapy. Mean pharmacokinetic parameters were determined, along with practical recommendations for initial vancomycin dosing that targeted steady-state trough concentrations for patients receiving intermittent infusions and steady-state levels for those receiving continuous infusions between 15 and 20 mg/L. Monte Carlo simulation was used to develop the initial vancomycin dosing recommendations.

RESULTS

The mean (95% confidence interval) pharmacokinetic parameters for vancomycin (elimination rate constant 0.0315 [0.0254-0.0391], half-life 22.0 h [17.72-27.24 h], volume of distribution 0.96 L/kg [0.77-1.20 L/kg], and clearance 2.4 L/h [1.97-2.92 L/h]) indicated that initial intermittent IV dosing of 1.25-1.5 g q24h or 15 mg/kg q24h would be suitable. For continuous infusion, a 1.5-g IV loading dose followed by continuous infusion of 1-1.5 g IV over 24 h (42-62 mg/h) would be recommended. However, Monte Carlo simulation revealed that the probability of achieving desired concentrations between 15 and 20 mg/L with any of these initial regimens is low.

CONCLUSIONS

There was considerable variation in vancomycin pharmacokinetics in this patient population. The observations reported here raise concerns about the reliability of numerous empiric dosing recommendations derived from small pharmacokinetic studies in heterogeneous populations. Follow-up therapeutic drug monitoring is essential to ensure that concentrations remain within the target range.

Audit and feedback to reduce broad-spectrum antibiotic use among intensive care unit patients: a controlled interrupted time series analysis

OBJECTIVE

We aimed to rigorously evaluate the impact of prospective audit and feedback on broad-spectrum antimicrobial use among critical care patients.

DESIGN

Prospective, controlled interrupted time series.

SETTING

Single tertiary care center with 3 intensive care units.

PATIENTS AND INTERVENTIONS

A formal review of all critical care patients on their third or tenth day of broad-spectrum antibiotic therapy was conducted, and suggestions for antimicrobial optimization were communicated to the critical care team.

OUTCOMES

The primary outcome was broad-spectrum antibiotic use (days of therapy per 1000 patient-days; secondary outcomes included overall antibiotic use, gram-negative bacterial susceptibility, nosocomial Clostridium difficile infections, length of stay, and mortality.

RESULTS

The mean monthly broad-spectrum antibiotic use decreased from 644 days of therapy per 1,000 patient-days in the preintervention period to 503 days of therapy per 1,000 patient-days in the postintervention period (P < .0001); time series modeling confirmed an immediate decrease (± standard error) of 119 ± 37.9 days of therapy per 1,000 patient-days (P = .0054). In contrast, no changes were identified in the use of broad-spectrum antibiotics in the control group (nonintervention medical and surgical wards) or in the use of control medications in critical care (stress ulcer prophylaxis). The incidence of nosocomial C. difficile infections decreased from 11 to 6 cases in the study intensive care units, whereas the incidence increased from 87 to 116 cases in the control wards (P = .04). Overall gram-negative susceptibility to meropenem increased in the critical care units. Intensive care unit length of stay and mortality did not change.

CONCLUSIONS

Institution of a formal prospective audit and feedback program appears to be a safe and effective means to improve broad-spectrum antimicrobial use in critical care.

Carbapenem-resistant Gram-negative bacilli in Canada 2009-10: results from the Canadian Nosocomial Infection Surveillance Program (CNISP)

OBJECTIVES

To investigate the occurrence and molecular mechanisms associated with carbapenemases in carbapenem-resistant Gram-negative isolates from Canadian cases.

METHODS

Twenty hospital sites across Canada submitted isolates for a 1 year period starting 1 September 2009. All Enterobacteriaceae with MICs ≥ 2 mg/L and Acinetobacter baumannii and Pseudomonas aeruginosa with MICs ≥ 16 mg/L of carbapenems were submitted to the National Microbiology Laboratory (NML) where carbapenem MICs were confirmed by Etest and isolates were characterized by PCR for carbapenemase genes, antimicrobial susceptibilities, PFGE and plasmid isolation.

RESULTS

A total of 444 isolates (298 P. aeruginosa, 134 Enterobacteriaceae and 12 A. baumannii) were submitted to the NML of which 274 (61.7%; 206 P. aeruginosa, 59 Enterobacteriaceae and 9 A. baumannii) met the inclusion criteria as determined by Etest. Carbapenemase genes were identified in 30 isolates: bla(GES-5) (n = 3; P. aeruginosa), bla(KPC-3) (n = 7; Enterobacteriaceae), bla(NDM-1) (n = 2; Enterobacteriaceae), bla(VIM-2) and bla(VIM-4) (n = 8; P. aeruginosa) bla(SME-2) (n = 1; Enterobacteriaceae) and bla(OXA-23) (n = m9; A. baumannii). PFGE identified a cluster in each of Enterobacteriaceae, P. aeruginosa and A. baumannii corresponding to isolates harbouring carbapenemase genes. Three KPC plasmid patterns (IncN and FllA) were identified where indistinguishable plasmid patterns were identified in unrelated clinical isolates.

CONCLUSIONS

Carbapenemases were rare at the time of this study. Dissemination of carbapenemases was due to both dominant clones and common plasmid backbones.

Risk of infection following a visit to the emergency department: a cohort study

BACKGROUND

The risk of infection following a visit to the emergency department is unknown. We explored this risk among elderly residents of long-term care facilities.

METHODS

We compared the rates of new respiratory and gastrointestinal infections among elderly residents aged 65 years and older of 22 long-term care facilities. We used standardized surveillance definitions. For each resident who visited the emergency department during the study period, we randomly selected two residents who did not visit the emergency department and matched them by facility unit, age and sex. We calculated the rates and proportions of new infections, and we used conditional logistic regression to adjust for potential confounding variables.

RESULTS

In total, we included 1269 residents of long-term care facilities, including 424 who visited the emergency department during the study. The baseline characteristics of residents who did or did not visit the emergency department were similar, except for underlying health status (visited the emergency department: mean Charlson Comorbidity Index 6.1, standard deviation [SD] 2.5; did not visit the emergency department: mean Charlson Comorbidity index 5.5, SD 2.7; p < 0.001) and the proportion who had visitors (visited the emergency department: 46.9%; did not visit the emergency department: 39.2%; p = 0.01). Overall, 21 (5.0%) residents who visited the emergency department and 17 (2.0%) who did not visit the emergency department acquired new infections. The incidence of new infections was 8.3/1000 patient-days among those who visited the emergency department and 3.4/1000 patient-days among those who did not visit the emergency department. The adjusted odds ratio for the risk of infection following a visit to the emergency department was 3.9 (95% confidence interval 1.4-10.8).

INTERPRETATION

A visit to the emergency department was associated with more than a threefold increased risk of acute infection among elderly people. Additional precautions should be considered for residents following a visit to the emergency department.

New Delhi metallo-β-lactamase-1: local acquisition in Ontario, Canada, and challenges in detection

New Delhi metallo-β-lactamase-1 (NDM-1) is a recently identified metallo-β-lactamase that confers resistance to carbapenems and all other β-lactam antibiotics, with the exception of aztreonam. NDM-1 is also associated with resistance to many other classes of antibiotics. The enzyme was first identified in organisms isolated from a patient in Sweden who had previously received medical treatment in India, but it is now recognized as endemic throughout India and Pakistan and has spread worldwide. The gene encoding NDM-1 has been found predominantly in Escherichia coli and Klebsiella pneumoniae. We describe the isolation NDM-1-producing organisms from two patients in Toronto, Ontario. To the best of our knowledge, this is the first report of an organism producing NDM-1 that was locally acquired in Canada. We also discuss the evidence that NDM-1 can affect bacterial species other than E. coli and K. pneumoniae, the limited options for treatment and the difficulty laboratories face in detecting organisms that produce NDM-1.

Effect of patterns of transferring patients among healthcare institutions on rates of nosocomial methicillin-resistant Staphylococcus aureus transmission: a Monte Carlo simulation

OBJECTIVE

To determine the effect of the rate and pattern of patient transfers among institutions within a single metropolitan area on the rates of methicillin-resistant Staphylococcus aureus (MRSA) transmission among patients in hospitals and nursing homes.

METHODS

A stochastic, discrete-time, Monte Carlo simulation was used to model the rate and spread of MRSA transmission among patients in medical institutions within a single metropolitan area. Admission, discharges, transfers, and nosocomial transmission were simulated with respect to different interinstitutional transfer strategies and various situational scenarios, such as outlier institutions with high transmission rates.

RESULTS

The simulation results indicated that transfer patterns and transfer rate changes do not affect nosocomial MRSA transmission. Outlier institutions with high transmission rates affect the system wide rate of nosocomial infections differently, depending on institution type.

CONCLUSION

It is worth effort to understanding disease-transmission dynamics and interinstitutional transfer patterns for the management of recently introduced diseases or strains. Once endemic in a system, other strategies for transmission control need to be implemented.

When should a diagnosis of influenza be considered in adults requiring intensive care unit admission? Results of population-based active surveillance in Toronto

Introduction

There is a paucity of data about the clinical characteristics that help identify patients at high risk of influenza infection upon ICU admission. We aimed to identify predictors of influenza infection in patients admitted to ICUs during the 2007/2008 and 2008/2009 influenza seasons and the second wave of the 2009 H1N1 influenza pandemic as well as to identify populations with increased likelihood of seasonal and pandemic 2009 influenza (pH1N1) infection.

Methods

Six Toronto acute care hospitals participated in active surveillance for laboratory-confirmed influenza requiring ICU admission during periods of influenza activity from 2007 to 2009. Nasopharyngeal swabs were obtained from patients who presented to our hospitals with acute respiratory or cardiac illness or febrile illness without a clear nonrespiratory aetiology. Predictors of influenza were assessed by multivariable logistic regression analysis and the likelihood of influenza in different populations was calculated.

Results

In 5,482 patients, 126 (2.3%) were found to have influenza. Admission temperature ≥38°C (odds ratio (OR) 4.7 for pH1N1, 2.3 for seasonal influenza) and admission diagnosis of pneumonia or respiratory infection (OR 7.3 for pH1N1, 4.2 for seasonal influenza) were independent predictors for influenza. During the peak weeks of influenza seasons, 17% of afebrile patients and 27% of febrile patients with pneumonia or respiratory infection had influenza. During the second wave of the 2009 pandemic, 26% of afebrile patients and 70% of febrile patients with pneumonia or respiratory infection had influenza.

Conclusions

The findings of our study may assist clinicians in decision making regarding optimal management of adult patients admitted to ICUs during future influenza seasons. Influenza testing, empiric antiviral therapy and empiric infection control precautions should be considered in those patients who are admitted during influenza season with a diagnosis of pneumonia or respiratory infection and are either febrile or admitted during weeks of peak influenza activity.

Defining criteria to interpret multilocus variable-number tandem repeat analysis to aid Clostridium difficile outbreak investigation

PFGE is currently the North American standard for surveillance for Clostridium difficile but lacks discriminatory power to aid outbreak investigation. A further limitation to PFGE is the high baseline rate of the epidemic North American pulsotype (NAP) 1 strain in hospitals. Multilocus variable-number tandem repeat analysis (MLVA) appears to have superior discriminatory power but criteria to define clonality have not been set. We conducted surveillance for toxin-positive C. difficile infection (CDI) at a single academic health sciences centre between September 2009 and April 2010. Seventy-four patient specimens resulting in 86 discrete CDI episodes were subjected to PFGE and MLVA. Results were analysed using Bionumerics software to generate phylogenetic trees and coupled to patient demographic data. Amongst the NAP1 strains, two distinct clusters were identified by MLVA using 90 % similarity as a cut-off by Manhattan distance-based clustering, four clusters using 95 % and seven clusters using 97 %. Population analysis conducted on multiple colonies (n = 25) demonstrated that 1-3 % difference in MLVA types was typical for a single individual. Typing was also conducted in the context of institutional outbreaks (n = 42, three outbreaks) in order to determine clusters within the NAP1 strain. By combining longitudinal surveillance with epidemiological information, single specimen population analysis and typing in the context of institutional outbreaks, we conclude that the use of the Manhattan distance-based clustering with a cut-off of 95-97 % is capable of distinguishing outbreak clones from sporadic isolates.

Impact of antimicrobial stewardship in critical care: a systematic review

OBJECTIVES

To evaluate the current state of evidence for antimicrobial stewardship interventions in the critical care unit.

METHODS

We performed a systematic search of OVID MEDLINE, Embase and Cochrane electronic databases from 1996-2010. Studies were included if they involved any experimental intervention to improve antimicrobial utilization in the critical care setting.

RESULTS

Thirty-eight studies met the inclusion criteria, of which 24 met our quality inclusion criteria. The quality of research was poor, with only 3 randomized controlled trials, 3 interrupted time series and 18 (75%) uncontrolled before-and-after studies. We identified six intervention types: studies of antibiotic restriction or pre-approval (six studies); formal infectious diseases physician consultation (five); implementation of guidelines or protocols for de-escalation (two); guidelines for antibiotic prophylaxis or treatment in intensive care (two); formal reassessment of antibiotics on a pre-specified day of therapy (three); and implementation of computer-assisted decision support (six). Stewardship interventions were associated with reductions in antimicrobial utilization (11%-38% defined daily doses/1000 patient-days), lower total antimicrobial costs (US$ 5-10/patient-day), shorter average duration of antibiotic therapy, less inappropriate use and fewer antibiotic adverse events. Stewardship interventions beyond 6 months were associated with reductions in antimicrobial resistance rates, although this differed by drug-pathogen combination. Antibiotic stewardship was not associated with increases in nosocomial infection rates, length of stay or mortality.

CONCLUSIONS

More rigorous research is needed, but available evidence suggests that antimicrobial stewardship is associated with improved antimicrobial utilization in the intensive care unit, with corresponding improvements in antimicrobial resistance and adverse events, and without compromise of short-term clinical outcomes.

Identification of major clonal complexes and toxin producing strains among Staphylococcus aureus associated with atopic dermatitis

Staphylococcus aureus promotes the onset and severity of atopic dermatitis (AD), which is exacerbated by superantigen toxins SEB and SEC. The genetic identity of these isolates, and their relationship to common hospital- or community-associated methicillin resistant S. aureus (HA-MRSA and CA-MRSA) has not been defined. We conducted spa typing, partial multi-locus sequence typing (MLST), and toxin profiling (seb, sec, lukS-PV) of S. aureus from 119 pediatric and 40 adult AD patients. MLST clonal complexes CC45, CC5, CC15, CC1, CC8 and CC30 accounted for 79% of isolates, representing the same major groups reported for nosocomial S. aureus in hospital intensive care units. The highest disease severity was associated with CC1, which was significantly greater relative to CC15 (p = 0.017) or CC30 (p = 0.040), but with no significant difference relative to CC45, CC5 or CC8. Although there were two few lukS-PV, seb or sec isolates to infer a role in disease severity, CC45 was identified as a source of SEC producing strains, and lukS-PVL was associated with a small number of CC5 pediatric isolates. CC1 harbored the only CA-MRSA that was identified, and was a source of isolates that expressed both seb and sec, and closely resembled the USA400 strain of CA-MRSA.

Epidemiology of influenza-associated hospitalization in adults, Toronto, 2007/8

The purpose of this investigation was to identify when diagnostic testing and empirical antiviral therapy should be considered for adult patients requiring hospitalization during influenza seasons. During the 2007/8 influenza season, six acute care hospitals in the Greater Toronto Area participated in active surveillance for laboratory-confirmed influenza requiring hospitalization. Nasopharyngeal (NP) swabs were obtained from patients presenting with acute respiratory or cardiac illness, or with febrile illness without clear non-respiratory etiology. Predictors of influenza were analyzed by multivariable logistic regression analysis and likelihoods of influenza infection in various patient groups were calculated. Two hundred and eighty of 3,917 patients were found to have influenza. Thirty-five percent of patients with influenza presented with a triage temperature >or=38.0 degrees C, 80% had respiratory symptoms in the emergency department, and 76% were >or=65 years old. Multivariable analysis revealed a triage temperature >or=38.0 degrees C (odds ratio [OR] 3.1; 95% confidence interval [CI] 2.3-4.1), the presence of respiratory symptoms (OR 1.7; 95% CI 1.2-2.4), admission diagnosis of respiratory infection (OR 1.8; 95% CI 1.3-2.4), admission diagnosis of exacerbation of chronic obstructive pulmonary disease (COPD)/asthma or respiratory failure (OR 2.3; 95% CI 1.6-3.4), and admission in peak influenza weeks (OR 4.2; 95% CI 3.1-5.7) as independent predictors of influenza. The likelihood of influenza exceeded 15% in patients with respiratory infection or exacerbation of COPD/asthma if the triage temperature was >or=38.0 degrees C or if they were admitted in the peak weeks during the influenza season. During influenza season, diagnostic testing and empiric antiviral therapy should be considered in patients requiring hospitalization if respiratory infection or exacerbation of COPD/asthma are suspected and if either the triage temperature is >or=38.0 degrees C or admission is during the weeks of peak influenza activity.

Risk factors for SARS transmission from patients requiring intubation: a multicentre investigation in Toronto, Canada

Background

In the 2003 Toronto SARS outbreak, SARS-CoV was transmitted in hospitals despite adherence to infection control procedures. Considerable controversy resulted regarding which procedures and behaviours were associated with the greatest risk of SARS-CoV transmission.

Methods

A retrospective cohort study was conducted to identify risk factors for transmission of SARS-CoV during intubation from laboratory confirmed SARS patients to HCWs involved in their care. All SARS patients requiring intubation during the Toronto outbreak were identified. All HCWs who provided care to intubated SARS patients during treatment or transportation and who entered a patient room or had direct patient contact from 24 hours before to 4 hours after intubation were eligible for this study. Data was collected on patients by chart review and on HCWs by interviewer-administered questionnaire. Generalized estimating equation (GEE) logistic regression models and classification and regression trees (CART) were used to identify risk factors for SARS transmission.

Results

45 laboratory-confirmed intubated SARS patients were identified. Of the 697 HCWs involved in their care, 624 (90%) participated in the study. SARS-CoV was transmitted to 26 HCWs from 7 patients; 21 HCWs were infected by 3 patients. In multivariate GEE logistic regression models, presence in the room during fiberoptic intubation (OR = 2.79, p = .004) or ECG (OR = 3.52, p = .002), unprotected eye contact with secretions (OR = 7.34, p = .001), patient APACHE II score ≥20 (OR = 17.05, p = .009) and patient Pa0₂/Fi0₂ ratio ≤59 (OR = 8.65, p = .001) were associated with increased risk of transmission of SARS-CoV. In CART analyses, the four covariates which explained the greatest amount of variation in SARS-CoV transmission were covariates representing individual patients.

Conclusion

Close contact with the airway of severely ill patients and failure of infection control practices to prevent exposure to respiratory secretions were associated with transmission of SARS-CoV. Rates of transmission of SARS-CoV varied widely among patients.

Health care-associated Clostridium difficile infection in Canada: patient age and infecting strain type are highly predictive of severe outcome and mortality

BACKGROUND

C. difficile infection (CDI) has become an important and frequent nosocomial infection, often resulting in severe morbidity or death. Severe CDI is more frequently seen among individuals infected with the emerging NAP1/027/BI (NAP1) strain and in the elderly population, but the relative importance of these 2 factors remains unclear. We used a large Canadian database of patients with CDI to explore the interaction between these 2 variables.

METHODS

The Canada-wide CDI study, performed in 2005 by the Canadian Nosocomial Infection Surveillance Program (CNISP), was used to analyze the role of infecting strain type and patient age on the severity of CDI. A severe outcome was defined as CDI requiring intensive care unit care, colectomy, or causing death (directly or indirectly) within 30 days after diagnosis.

RESULTS

A total of 1008 patients in the CNISP database had both complete clinical data and infecting strain analysis documented. A total of 311 patients (31%) were infected with the NAP1 strain, 83 (28%) were infected with the NAP2/J strain, and the rest were infected with various other types. The proportion of NAP1 infections correlated with the incidence and the severity of CDI when analyzed by province. Thirty-nine (12.5%) of the infections due to the NAP1 strain resulted in a severe outcome, compared with only 41 (5.9%) of infections due to the other types (P < .001). The patient's age was strongly associated with a severe outcome, and patients 60-90 years of age were approximately twice as likely to experience a severe outcome if the infection was due to NAP1, compared with infections due to other types.

CONCLUSIONS

Our study confirms the strong age association with infection due to the NAP1 strain and severe CDI. In addition, patients 60-90 years of age infected with NAP1 are approximately twice as likely to die or to experience a severe CDI-related outcome, compared with those with non-NAP1 infections. Patients >90 years of age experience high rates of severe CDI, regardless of strain type.

Health care-associated Clostridium difficile infection in adults admitted to acute care hospitals in Canada: a Canadian Nosocomial Infection Surveillance Program Study

BACKGROUND

Clostridium difficile infection (CDI) is the most frequent cause of health care-associated infectious diarrhea in industrialized countries. The only previous report describing the incidence of health care-associated CDI (HA CDI) in Canada was conducted in 1997 by the Canadian Nosocomial Infection Surveillance Program. We re-examined the incidence of HA CDI with an emphasis on patient outcomes.

METHODS

A prospective surveillance was conducted from 1 November 2004 through 30 April 2005. Basic demographic data were collected, including age, sex, type of patient ward where the patient was hospitalized on the day HA CDI was identified, and patient comorbidities. Data regarding severe outcome were collected 30 days after the diagnosis of HA CDI; severe outcome was defined as an admission to the intensive care unit because of complications of CDI, colectomy due to CDI, and/or death attributable to CDI.

RESULTS

A total of 1430 adults with HA CDI were identified in 29 hospitals during the 6-month surveillance period. The overall incidence rate of HA CDI for adult patients admitted to these hospitals was 4.6 cases per 1000 patient admissions and 65 per 100,000 patient-days. At 30 days after onset of HA CDI, 233 patients (16.3%) had died from all causes; 31 deaths (2.2%) were a direct result of CDI, and 51 deaths (3.6%) were indirectly related to CDI, for a total attributable mortality rate of 5.7%.

CONCLUSIONS

The rates are remarkably similar to those found in our previous study; although we found wide variations in HA CDI among the participating hospitals. However, the attributable mortality increased almost 4-fold (5.7% vs. 1.5%; P<.001).

Health care-associated Clostridium difficile infection in adults admitted to acute care hospitals in Canada: a Canadian Nosocomial Infection Surveillance Program Study

BACKGROUND

Clostridium difficile infection (CDI) is the most frequent cause of health care-associated infectious diarrhea in industrialized countries. The only previous report describing the incidence of health care-associated CDI (HA CDI) in Canada was conducted in 1997 by the Canadian Nosocomial Infection Surveillance Program. We re-examined the incidence of HA CDI with an emphasis on patient outcomes.

METHODS

A prospective surveillance was conducted from 1 November 2004 through 30 April 2005. Basic demographic data were collected, including age, sex, type of patient ward where the patient was hospitalized on the day HA CDI was identified, and patient comorbidities. Data regarding severe outcome were collected 30 days after the diagnosis of HA CDI; severe outcome was defined as an admission to the intensive care unit because of complications of CDI, colectomy due to CDI, and/or death attributable to CDI.

RESULTS

A total of 1430 adults with HA CDI were identified in 29 hospitals during the 6-month surveillance period. The overall incidence rate of HA CDI for adult patients admitted to these hospitals was 4.6 cases per 1000 patient admissions and 65 per 100,000 patient-days. At 30 days after onset of HA CDI, 233 patients (16.3%) had died from all causes; 31 deaths (2.2%) were a direct result of CDI, and 51 deaths (3.6%) were indirectly related to CDI, for a total attributable mortality rate of 5.7%.

CONCLUSIONS

The rates are remarkably similar to those found in our previous study; although we found wide variations in HA CDI among the participating hospitals. However, the attributable mortality increased almost 4-fold (5.7% vs. 1.5%; P<.001).

Infection control practices related to Clostridium difficile infection in acute care hospitals in Canada

BACKGROUND

We carried out a survey to identify the infection prevention and control practices in place in Canadian hospitals participating in the Canadian Nosocomial Infection Surveillance Program (CNISP).

METHODS

An infection prevention and control practices survey was sent to CNISP hospitals at the beginning of November 2004, the same time that CNISP started a 6-month prospective surveillance for Clostridium difficile infection (CDI) to evaluate their infection prevention and control measures and laboratory methods for C difficile.

RESULTS

A total of 33 hospitals completed and returned the survey. Infection control precautions were initiated in 18 hospitals (55%) due to the presence of a symptomatic patient before the C difficile laboratory tests were available. All of the hospitals used gloves and gowns as additional precautions. Twenty-three hospitals (70%) tested liquid stools based on a clinician's order, and 8 (24%) tested all liquid stools submitted whether of not C difficile testing was requested. The hospitals used 1 of 3 different products as a standard hospital-wide disinfectant; 24 (73%) used a quaternary ammonium compound, 8 (24%) used accelerated hydrogen peroxide, and 1 (3%) used a hypochlorite solution (1:10 bleach solution).

CONCLUSION

Although the hospitals used contact precautions quite uniformly, considerable variation was seen among hospitals in terms of testing strategies, cleaning and disinfection protocols and products, and isolation practices. The timing for the initiation of infection control precautions is important to prevent secondary transmission of CDI. Most of the hospitals implemented precautions while waiting for the toxin assay results.

Variation in mortality rates among long-term care facilities for residents with lower respiratory tract infection

OBJECTIVE

To identify variables contributing to interfacility differences in mortality among residents of long-term care facilities who have lower respiratory tract infection.

DESIGN

Multicenter, prospective, 1-year observational study.

SETTING

Twenty-one long-term care facilities in 4 geographic areas of Canada.

PARTICIPANTS

Residents of long-term care facilities prescribed antimicrobials for treatment of lower respiratory tract infection.

METHODS

Mortality rates were calculated for 3 definitions of lower respiratory tract infection: episodes with a clinical or radiographic diagnosis and treated with antimicrobials (definition 1); episodes with a physician diagnosis of pneumonia (definition 2); and episodes with chest radiography findings consistent with pneumonia (definition 3). Multilevel modeling was used to evaluate variables describing premorbid resident status, clinical presentation, management, and facility characteristics. Multivariable models were developed to identify independent predictors of mortality and determine whether facility-level variables remained independently associated with mortality rate after incorporation of individual-level variables.

RESULTS

Facility mortality rates varied from 0% to 17.8% for definition 1, from 0% to 47.1% for definition 2, and from 0% to 37.5% for definition 3. There were significant differences in mortality rate depending on which definition was used; for definitions 1 and 2, there were significant differences in mortality rate across facilities. Poorer premorbid resident status and a more severe presentation remained independent predictors of mortality in the multivariable analysis. There were also significantly increased mortality rates for episodes in which a fluoroquinolone was prescribed for initial treatment. For definitions 1 and 3, facility-level variables remained independently associated with mortality rate in the final multivariable model.

CONCLUSIONS

Rates of mortality due to lower respiratory tract infection varied among long-term care facilities and differed within a facility, depending on the definition applied. Variables describing premorbid resident status, severity of presentation, and management did not fully explain the variation in mortality rate. Some facility-level variables remained independent predictors of mortality.