Rosie D. Lyles

The Preventability of Ventilator-Associated Events: The CDC Prevention Epicenters’ Wake Up and Breathe Collaborative

RATIONALE The CDC introduced ventilator-associated event (VAE) definitions in January 2013. Little is known about VAE prevention. We hypothesized that daily, coordinated spontaneous awakening trials (SATs) and spontaneous breathing trials (SBTs) might prevent VAEs. OBJECTIVES To assess the preventability of VAEs. METHODS We nested a multicenter quality improvement collaborative within a prospective study of VAE surveillance among 20 intensive care units between November 2011 and May 2013. Twelve units joined the collaborative and implemented an opt-out protocol for nurses and respiratory therapists to perform paired daily SATs and SBTs. The remaining eight units conducted surveillance alone. We measured temporal trends in VAEs using generalized mixed effects regression models adjusted for patient-level unit, age, sex, reason for intubation, Sequential Organ Failure Assessment score, and comorbidity index. MEASUREMENTS AND MAIN RESULTS We tracked 5,164 consecutive episodes of mechanical ventilation: 3,425 in collaborative units and 1,739 in surveillance-only units. Within collaborative units, significant increases in SATs, SBTs, and percentage of SBTs performed without sedation were mirrored by significant decreases in duration of mechanical ventilation and hospital length-of-stay. There was no change in VAE risk per ventilator day but significant decreases in VAE risk per episode of mechanical ventilation (odds ratio [OR], 0.63; 95% confidence interval [CI], 0.42-0.97) and infection-related ventilator-associated complications (OR, 0.35; 95% CI, 0.17-0.71) but not pneumonias (OR, 0.51; 95% CI, 0.19-1.3). Within surveillance-only units, there were no significant changes in SAT, SBT, or VAE rates. CONCLUSIONS Enhanced performance of paired, daily SATs and SBTs is associated with lower VAE rates. Clinical trial registered with www.clinicaltrials.gov (NCT 01583413).

Relationship between Chlorhexidine Gluconate Skin Concentration and Microbial Density on the Skin of Critically Ill Patients Bathed Daily with Chlorhexidine Gluconate

OBJECTIVE AND DESIGN Previous work has shown that daily skin cleansing with chlorhexidine gluconate (CHG) is effective in preventing infection in the medical intensive care unit (MICU). A colorimetric, semiquantitative indicator was used to measure CHG concentration on skin (neck, antecubital fossae, and inguinal areas) of patients bathed daily with CHG during their MICU stay and after discharge from the MICU, when CHG bathing stopped. PATIENTS AND SETTING MICU patients at Rush University Medical Center. METHODS CHG concentration on skin was measured and skin sites were cultured quantitatively. The relationship between CHG concentration and microbial density on skin was explored in a mixed-effects model using gram-positive colony-forming unit (CFU) counts. RESULTS For 20 MICU patients studied (240 measurements), the lowest CHG concentrations (0-18.75 μg/mL) and the highest gram-positive CFU counts were on the neck (median, 1.07 log(10) CFUs; [Formula: see text]). CHG concentration increased postbath and decreased over 24 hours ([Formula: see text]). In parallel, median log(10) CFUs decreased pre- to postbath (0.78 to 0) and then increased over 24 hours to the baseline of 0.78 ([Formula: see text]). A CHG concentration above 18.75 μg/mL was associated with decreased gram-positive CFUs ([Formula: see text]). In all but 2 instances, CHG was detected on patient skin during the entire interbath (approximately 24-hour) period (18 [90%] of 20 patients). In 11 patients studied after MICU discharge (80 measurements), CHG skin concentrations fell below effective levels after 1-3 days. CONCLUSION In MICU patients bathed daily with CHG, CHG concentration was inversely associated with microbial density on skin; residual antimicrobial activity on skin persisted up to 24 hours. Determination of CHG concentration on the skin of patients may be useful in monitoring the adequacy of skin cleansing by healthcare workers.

Predictors of Clinical Virulence in Community-Onset Methicillin-Resistant Staphylococcus aureus Infections: The Importance of USA300 and Pneumonia

BACKGROUND Though USA300 community-onset methicillin-resistant Staphylococcus aureus (CO-MRSA) has emerged as a major public health concern in the United States, its relative virulence is unknown. We sought to evaluate if the USA300 strain of CO-MRSA causes more severe infections than other MRSA (ie, USA100, -500, -800, and others) strains. METHODS An epidemiologic study was conducted from 2000 to 2007 to measure rates of severe infection. A matched case-control study was conducted from 2004 to 2006 to assess the relationship of strain type, syndrome, and severity of infection. Severe illness was defined as CO-MRSA infections with medical intensive care unit (MICU) admission or death within 1 week of admission. Controls were those with CO-MRSA infection without MICU admission. RESULTS We found an incidence of 75 cases per 100000 people of CO-MRSA infection in 2000, which increased to a rate of 396 per 100000 in 2007 (relative risk [RR], 5.3; 95% confidence interval [CI], 4.47-6.27). The incidence of severe infections increased from 5 cases per 100000 in 2000 to 17 per 100000 in 2007 (RR, 3.4; 95% CI; 1.67-6.43). USA300 strains were negatively associated with severe clinical courses or death as compared with other MRSA strain types. The highest risk of severe infection was found in those with pulmonary embolic infiltrates and bacteremia in the setting of USA300 infection (odds ratio, 31.41; 95% CI, 6.40-154.23). CONCLUSIONS Our findings suggest that USA300 infections are negatively associated with severe clinical courses, suggesting less virulence than other MRSA strains, except in the setting of pneumonia with septic pulmonary emboli.

Use of Medicare Claims to Rank Hospitals by Surgical Site Infection Risk following Coronary Artery Bypass Graft Surgery

OBJECTIVE To evaluate whether longitudinal insurer claims data allow reliable identification of elevated hospital surgical site infection (SSI) rates. DESIGN We conducted a retrospective cohort study of Medicare beneficiaries who underwent coronary artery bypass grafting (CABG) in US hospitals performing at least 80 procedures in 2005. Hospitals were assigned to deciles by using case mix-adjusted probabilities of having an SSI-related inpatient or outpatient claim code within 60 days of surgery. We then reviewed medical records of randomly selected patients to assess whether chart-confirmed SSI risk was higher in hospitals in the worst deciles compared with the best deciles. PARTICIPANTS Fee-for-service Medicare beneficiaries who underwent CABG in these hospitals in 2005. RESULTS We evaluated 114,673 patients who underwent CABG in 671 hospitals. In the best decile, 7.8% (958/12,307) of patients had an SSI-related code, compared with 24.8% (2,747/11,068) in the worst decile ([Formula: see text]). Medical record review confirmed SSI in 40% (388/980) of those with SSI-related codes. In the best decile, the chart-confirmed annual SSI rate was 3.2%, compared with 9.4% in the worst decile, with an adjusted odds ratio of SSI of 2.7 (confidence interval, 2.2-3.3; [Formula: see text]) for CABG performed in a worst-decile hospital compared with a best-decile hospital. CONCLUSIONS Claims data can identify groups of hospitals with unusually high or low post-CABG SSI rates. Assessment of claims is more reproducible and efficient than current surveillance methods. This example of secondary use of routinely recorded electronic health information to assess quality of care can identify hospitals that may benefit from prevention programs.

The effectiveness of routine daily chlorhexidine gluconate bathing in reducing Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae skin burden among long-term acute care hospital patients.

We evaluated the effectiveness of daily chlorhexidine gluconate (CHG) bathing in decreasing skin carriage of Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae (KPC) among long-term acute care hospital patients. CHG bathing reduced KPC skin colonization, particularly when CHG skin concentrations greater than or equal to 128 μg/mL were achieved.

Lost in translation? Reliability of assessing inpatient antimicrobial appropriateness with use of computerized case vignettes.

OBJECTIVE To describe and measure reliability of a computer-assisted method of case vignette assembly and expert review to assess the appropriateness of antimicrobial therapy for hospitalized adults. DESIGN Feasibility and reliability analysis of computer-assisted tool used to compare the effects of antimicrobial stewardship interventions. SETTING Public teaching hospital. PATIENTS Randomly selected adult antimicrobial recipients admitted to inpatient medicine services. METHODS Clinical data abstracted from 504 paper medical records were merged with computerized laboratory and pharmacy data to assemble case vignettes that underwent expert review for appropriateness. We performed 3 validations, as follows: data for 35 vignettes abstracted independently by 2 research assistants were assessed for interrater agreement, expert review of 24 vignettes was compared with review of the corresponding paper medical records, and interrater reliability of antimicrobial appropriateness assessments by 2 experts was determined for 70 case vignettes. RESULTS Vignette assembly and expert review each required 10-12 minutes per case. Potentially important discrepancies occurred in 0%-32% of clinical findings abstracted independently by 2 research assistants. Expert review of 24 vignettes and the corresponding full paper medical records yielded fair agreement (kappa, 0.30). The 2 experts identified inappropriate initial antimicrobial therapy in 67% and 61% of case vignettes reviewed independently; interrater agreement was improved after sequential case discussion and stringent application of appropriateness criteria (kappa, 0.72). CONCLUSIONS Our case vignette assembly and expert review method is efficient, but improvements in both technical and human performance are needed to be able to yield valid estimates of the prevalence of inappropriate antimicrobial use. Assessments of antimicrobial appropriateness require validation.

Modeling Spread of KPC-Producing Bacteria in Long-Term Acute Care Hospitals in the Chicago Region, USA

OBJECTIVE Prevalence of bla KPC-encoding Enterobacteriaceae (KPC) in Chicago long-term acute care hospitals (LTACHs) rose rapidly after the first recognition in 2007. We studied the epidemiology and transmission capacity of KPC in LTACHs and the effect of patient cohorting. METHODS Data were available from 4 Chicago LTACHs from June 2012 to June 2013 during a period of bundled interventions. These consisted of screening for KPC rectal carriage, daily chlorhexidine bathing, medical staff education, and 3 cohort strategies: a pure cohort (all KPC-positive patients on 1 floor), single rooms for KPC-positive patients, and a mixed cohort (all KPC-positive patients on 1 floor, supplemented with KPC-negative patients). A data-augmented Markov chain Monte Carlo (MCMC) method was used to model the transmission process. RESULTS Average prevalence of KPC colonization was 29.3%. On admission, 18% of patients were colonized; the sensitivity of the screening process was 81%. The per admission reproduction number was 0.40. The number of acquisitions per 1,000 patient days was lowest in LTACHs with a pure cohort ward or single rooms for colonized patients compared with mixed-cohort wards, but 95% credible intervals overlapped. CONCLUSIONS Prevalence of KPC in LTACHs is high, primarily due to high admission prevalence and the resultant impact of high colonization pressure on cross transmission. In this setting, with an intervention in place, patient-to-patient transmission is insufficient to maintain endemicity. Inclusion of a pure cohort or single rooms for KPC-positive patients in an intervention bundle seemed to limit transmission compared to use of a mixed cohort.

Modifiable Risk Factors for the Spread of Klebsiella pneumoniae Carbapenemase-Producing Enterobacteriaceae Among Long-Term Acute-Care Hospital Patients

OBJECTIVE To identify modifiable risk factors for acquisition of Klebsiella pneumoniae carbapenemase-producing Enterobacteriaceae (KPC) colonization among long-term acute-care hospital (LTACH) patients. DESIGN Multicenter, matched case-control study. SETTING Four LTACHs in Chicago, Illinois. PARTICIPANTS Each case patient included in this study had a KPC-negative rectal surveillance culture on admission followed by a KPC-positive surveillance culture later in the hospital stay. Each matched control patient had a KPC-negative rectal surveillance culture on admission and no KPC isolated during the hospital stay. RESULTS From June 2012 to June 2013, 2,575 patients were admitted to 4 LTACHs; 217 of 2,144 KPC-negative patients (10.1%) acquired KPC. In total, 100 of these patients were selected at random and matched to 100 controls by LTACH facility, admission date, and censored length of stay. Acquisitions occurred a median of 16.5 days after admission. On multivariate analysis, we found that exposure to higher colonization pressure (OR, 1.02; 95% CI, 1.01-1.04; P=.002), exposure to a carbapenem (OR, 2.25; 95% CI, 1.06-4.77; P=.04), and higher Charlson comorbidity index (OR, 1.14; 95% CI, 1.01-1.29; P=.04) were independent risk factors for KPC acquisition; the odds of KPC acquisition increased by 2% for each 1% increase in colonization pressure. CONCLUSIONS Higher colonization pressure, exposure to carbapenems, and a higher Charlson comorbidity index independently increased the odds of KPC acquisition among LTACH patients. Reducing colonization pressure (through separation of KPC-positive patients from KPC-negative patients using strict cohorts or private rooms) and reducing carbapenem exposure may prevent KPC cross transmission in this high-risk patient population. Infect Control Hosp Epidemiol 2017;38:670-677.

Electronic Algorithmic Prediction of Central Vascular Catheter Use

OBJECTIVE To develop prediction algorithms for the presence of a central vascular catheter in hospitalized patients with use of data present in an electronic health record. Such algorithms could be used for measurement of device utilization rates and for clinical decision support rules. DESIGN Criterion standard. SETTING John H. Stroger, Jr, Hospital of Cook County, a 464-bed public hospital in Chicago, Illinois. PARTICIPANTS Patients admitted to the medical intensive care unit from May 31, 2005 through June 26, 2006 (derivation data set, May 31, 2005-September 28, 2005; validation data set, September 29, 2005-June 28, 2006). METHODS Covariates were collected from the electronic medical record for each patient; the outcome variable was presence of a central vascular device. Multivariate models were developed using the derivation set and the generalized estimating equation. Three models, each with increasing database requirements, were validated using the validation set. Device utilization ratios and performance characteristics were calculated. RESULTS Although Charlson score and duration of intensive care unit stay were significant predictors in all models, factors that indicated use or presence of a central line were also important. Device utilization rates derived from the algorithmic models were as accurate as those obtained using manual sampling. CONCLUSIONS Automated calculation of central vascular catheter use is both feasible and accurate, providing estimates statistically similar to those obtained using manual surveillance. Prediction modeling of central vascular catheter use may enable automated surveillance of bloodstream infections and enhance important prevention interventions, such as timely removal of unnecessary central lines.

Computer-Assisted Antimicrobial Recommendations for Optimal Therapy: Analysis of Prescribing Errors in an Antimicrobial Stewardship Trial

Clinician education and prospective audit and feedback interventions, deployed separately and concurrently, did not reduce antimicrobial use errors or rates compared to a control group of general medicine inpatients at our public hospital. Additional research is needed to define the optimal scope and intensity of hospital antimicrobial stewardship interventions. Infect Control Hosp Epidemiol 2017;38:857-859.