Infections following left ventricular assist device implantation and 1-year health-related quality of life

BACKGROUND

Left ventricular assist device (LVAD) implantation leads to substantial and sustained improvement in health-related quality of life (HRQOL) among patients. Infection following device implantation remains an important and frequent complication and adversely affects patient-reported HRQOL.

METHODS

Patients in The Society of Thoracic Surgeons' Interagency Registry for Mechanically Assisted Circulatory Support receiving a primary LVAD between April 2012 to October 2016 were included. The primary exposure was one-year post-implant infection, characterized by: (1) any infection; (2) total number of infections and (3) type (LVAD-specific, LVAD-related, non-LVAD). The association between infection and the primary composite adverse outcome (defined as EuroQoL Visual Analog Scale< 65, too sick to complete the survey, or death at 1-year) was estimated using inverse probability weighting and Cox regression.

RESULTS

The study cohort included 11,618 patients from 161 medical centers with 4,768 (41.0%) patients developing an infection, and 2,282 (19.6%) patients having> 1 infection during the follow up period. The adjusted odds ratio for the primary composite adverse outcome was 1.22 (95% CI, 1.19-1.24, p < 0.001) for each additional infection. Each additional infection was associated with a 3.49% greater probability of the primary composite outcome and was associated with worse performance across multiple dimensions of HRQOL as assessed by the EQ-5D for patients who survived to 1 year.

CONCLUSIONS

For patients undergoing LVAD implantation, each additional infection within the first post-implantation year was associated with an incremental negative effect on survival free of impaired HRQOL.

Mortality following durable left ventricular assist device implantation by timing and type of first infection

OBJECTIVE

Although infections are common after left ventricular assist device implantation, the relationship between timing and type of first infection with regard to mortality is less well understood.

METHODS

The Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support patients receiving a primary left ventricular assist device from April 2012 to May 2017 were included. The primary exposure was defined 3 ways: any infection, timing of first infection (early: ≤90 days; intermediate: 91-180 days; late: >180 days), and type (ventricular assist device specific, ventricular assist device related, non-ventricular assist device). The association between first infection and all-cause mortality was estimated using Cox regression.

RESULTS

The cohort included 12,957 patients at 166 centers (destination therapy: 47.4%, bridge-to-transplant: 41.2%). First infections were most often non-ventricular assist device (54.2%). Rates of first infection were highest in the early interval (10.7/100 person-months). Patients with any infection had a significantly higher adjusted hazard of death (hazard ratio, 2.63; 2.46-2.86). First infection in the intermediate interval was associated with the largest increase in adjusted hazard of death (hazard ratio, 3.26; 2.82-3.78), followed by late (hazard ratio, 3.13; 2.77-3.53) and early intervals (hazard ratio, 2.37; 2.16-2.60). Ventricular assist device-related infections were associated with the largest increase in hazard of death (hazard ratio, 3.02; 2.69-3.40), followed by ventricular assist device specific (hazard ratio, 2.92; 2.57-3.32) and non-ventricular assist device (hazard ratio, 2.42; 2.20-2.65).

CONCLUSIONS

Relative to those without infection, patients with any postimplantation infection had an increased risk of death. Ventricular assist device-related infections and infections occurring in the intermediate interval were associated with the largest increase in risk of death. After left ventricular assist device implantation, infection prevention strategies should target non-ventricular assist device infections in the first 90 days, then shift to surveillance/prevention of driveline infections after 90 days.

Incompleteness of health-related quality of life assessments before left ventricular assist device implant: A novel quality metric

BACKGROUND

Improved health-related quality of life (HRQOL) is an important outcome following durable left ventricular assist device (LVAD) implant. However, half of pre-implant HRQOL data are incomplete in The Society of Thoracic Surgeons' Intermacs registry. Pre-implant HRQOL incompleteness may reflect patient status or hospital resources to capture HRQOL data. We hypothesized that pre-implant HRQOL incompleteness predicts 90 day outcomes and serves as a novel quality metric.

METHODS

Risk factors for pre-implant HRQOL (EQ-5D-5L visual analog scale; 12-item Kansas City Cardiomyopathy Questionnaire "KCCQ") incompleteness were examined by stepwise logistic modeling. Direct standardization method was used to calculate adjusted incompleteness rates using a mixed effects logistic model. Hospitals were dichotomized as low or high based on median adjusted incompleteness rates. Andersen-Gill models were used to associate pre-implant HRQOL adjusted incompleteness rate with adverse events within 90 day post-implant.

RESULTS

The study cohort included 14,063 patients receiving a primary LVAD (4/2012-8/2017). HRQOL incompleteness at high-rate hospitals was more often due to administrative reasons (risk difference, EQ-5D: 10.1%; KCCQ-12: 11.6%) and less likely due to patient reasons (risk difference, EQ-5D: -8.9%; KCCQ-12: -11.4%). A 10% increase in the adjusted pre-implant EQ-5D incompleteness rate was significantly associated with higher risk of infection-related mortality (HR: 1.09), infection (HR: 1.05), and renal dysfunction (HR: 1.03). A 10% increase in the adjusted pre-implant KCCQ-12 incompleteness rate was significantly associated with higher risk of infection (HR: 1.04).

CONCLUSIONS

Hospital adjusted pre-implant HRQOL incompleteness was predictive of 90-day post-implant outcomes and may serve as a novel quality metric.

Association Between Care Fragmentation and Total Spending After Durable Left Ventricular Device Implant: A Mediation Analysis of Health Care-Associated Infections Within a National Medicare-Society of Thoracic Surgeons Intermacs Linked Dataset

BACKGROUND

Care fragmentation is associated with higher rates of infection after durable left ventricular assist device (LVAD) implant. Less is known about the relationship between care fragmentation and total spending, and whether this relationship is mediated by infections.

METHODS

Total payments were captured from admission to 180 days post-discharge. Drawing on network theory, a measure of care fragmentation was developed based on the number of shared patients among providers (ie, anesthesiologists, cardiac surgeons, cardiologists, critical care specialists, nurse practitioners, physician assistants) caring for 4,987 Medicare beneficiaries undergoing LVAD implantation between July 2009 - April 2017. Care fragmentation was measured using average path length, which describes how efficiently information flows among network members; longer path length indicates greater fragmentation. Terciles based on the level of care fragmentation and multivariable regression were used to analyze the relationship between care fragmentation and LVAD payments and mediation analysis was used to evaluate the role of post-implant infections.

RESULTS

The patient cohort was 81% male, 73% white, 11% Intermacs Profile 1 with mean (SD) age of 63.1 years (11.1). The mean (SD) level of care fragmentation in provider networks was 1.7 (0.2) and mean (SD) payment from admission to 180 days post-discharge was $246,905 ($109,872). Mean (SD) total payments at the lower, middle, and upper terciles of care fragmentation were $250,135 ($111,924), $243,288 ($109,376), and $247,290 ($108,241), respectively. In mediation analysis, the indirect effect of care fragmentation on total payments, through infections, was positive and statistically significant (β=16032.5, p=0.008).

CONCLUSIONS

Greater care fragmentation in the delivery of care surrounding durable LVAD implantation is associated with a higher incidence of infections, and consequently, higher payments for Medicare beneficiaries. Interventions to reduce care fragmentation may reduce the incidence of infections and in turn enhance the value of care for patients undergoing durable LVAD implantation.

Urinary Tract Infections: 2021 Update

Catheter-associated urinary tract infection (CAUTI) remains one of the most prevalent, but preventable, health care-associated infections and predominantly occurs in patients with indwelling urinary catheters. Duration of urinary catheterization is the most important modifiable risk factor for development of CAUTI. Alternatives to indwelling catheters should be considered in appropriate patients. If indwelling catheterization is necessary, proper aseptic practices for catheter insertion and maintenance and use of a closed catheter collection system are essential for preventing CAUTI. The use of intervention bundles and collaboratives helps in the effective implementation of CAUTI prevention measures.

Interhospital variability in health care-associated infections and payments after durable ventricular assist device implant among Medicare beneficiaries

OBJECTIVE

The objective of this study was to investigate variations across hospitals in infection rates and associated costs, the latter reflected in 90-day Medicare payments. Despite high rates and expenditures of health care--associated infections associated with durable ventricular assist device implantation, few studies have examined interhospital variation and associated costs.

METHODS

Clinical data on 8688 patients who received primary durable ventricular assist devices from July 2008 to July 2017 from the Society of Thoracic Surgeons Interagency Registry for Mechanically Assisted Circulatory Support (Intermacs) hospitals (n = 120) were merged with postimplantation 90-day Medicare claims. Terciles of hospital-specific, risk-adjusted infection rates per 100 patient-months were estimated using Intermacs and associated with Medicare payments (among 5440 Medicare beneficiaries). Primary outcomes included infections within 90 days of implantation and Medicare payments.

RESULTS

There were 3982 infections identified among 27.8% (2417/8688) of patients developing an infection. The median (25th, 75th percentile) adjusted incidence of infections (per 100 patient-months) across hospitals was 14.3 (9.3, 19.5) and varied according to hospital (range, 0.0-35.6). Total Medicare payments from implantation to 90 days were 9.0% (absolute difference: $13,652) greater in high versus low infection tercile hospitals (P < .0001). The period between implantation to discharge accounted for 73.1% of the difference in payments during the implantation to 90-day period across terciles.

CONCLUSIONS

Health care--associated infection rates post durable ventricular assist device implantation varied according to hospital and were associated with increased 90-day Medicare expenditures. Interventions targeting preventing infections could improve the value of durable ventricular assist device support from the societal and hospital perspectives.

Authorship Correction: Understanding and Addressing Variation in Health Care-Associated Infections After Durable Ventricular Assist Device Therapy: Protocol for a Mixed Methods Study

[This corrects the article DOI: 10.2196/14701.].

Understanding and Addressing Variation in Health Care-Associated Infections After Durable Ventricular Assist Device Therapy: Protocol for a Mixed Methods Study

BACKGROUND

Durable ventricular assist device (VAD) therapy is reserved for patients with advanced heart failure who have a poor estimated 1-year survival. However, despite highly protocolized management processes, patients are at a unique risk for developing a health care-associated infection (HAI). Few studies have examined optimal strategies for HAI prevention after durable VAD implantation, despite variability in rates across centers and their impact on short- and long-term outcomes.

OBJECTIVE

The objective of this study is to develop recommendations for preventing the most significant HAIs after durable VAD implantation. The study has 3 specific aims: (1) identify determinants of center-level variability in HAI rates, (2) develop comprehensive understanding of barriers and facilitators for achieving low center-level HAI rates, and (3) develop and disseminate a best practices toolkit for preventing HAIs that accommodates various center contexts.

METHODS

This is a sequential mixed methods study starting with a cross-sectional assessment of current practices. To address aim 1, we will conduct (1) a systematic review of HAI prevention studies and (2) in-depth quantitative analyses using administrative claims, in-depth clinical data, and organizational surveys of VAD centers. For aim 2, we will apply a mixed methods patient tracer assessment framework to conduct semistructured interviews, field observations, and document analysis informed by findings from aim 1 at 5 high-performing (ie, low HAIs) and 5 low-performing (ie, high HAI) centers, which will be examined using a mixed methods case series analysis. For aim 3, we will build upon the findings from the previous aims to develop and field test an HAI preventive toolkit, acquire stakeholder input at an annual cardiac surgical conference, disseminate the final version to VAD centers nationwide, and conduct follow-up surveys to assess the toolkit's adoption.

RESULTS

The project was funded by the Agency for Healthcare Research and Quality in 2018 and enrollment for the overall project is ongoing. Data analysis is currently under way and the first results are expected to be submitted for publication in 2019.

CONCLUSIONS

This mixed methods study seeks to quantitatively assess the determinants of HAIs across clinical centers and qualitatively identify the context-specific facilitators and barriers for attaining low HAI rates. The mixed data findings will be used to develop and disseminate a stakeholder-acceptable toolkit of evidence-based HAI prevention recommendations that will accommodate the specific contexts and needs of VAD centers.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/14701.

Collaborative Quality Improvement Reduces Postoperative Pneumonia After Isolated Coronary Artery Bypass Grafting Surgery

BACKGROUND

To date, studies evaluating outcome improvements associated with participation in physician-led collaboratives have been limited by the absence of a contemporaneous control group. We examined post cardiac surgery pneumonia rates associated with participation in a statewide, quality improvement collaborative relative to a national physician reporting program.

METHODS AND RESULTS

We evaluated 911 754 coronary artery bypass operations (July 1, 2011, to June 30, 2017) performed across 1198 hospitals participating in a voluntary national physician reporting program (Society of Thoracic Surgeons [STS]), including 33 that participated in a Michigan-based collaborative (MI-Collaborative). Unlike STS hospitals not participating in the MI-Collaborative (i.e., STSnonMI) that solely received blinded reports, MI-Collaborative hospitals received a multi-faceted intervention starting November 2012 (quarterly in-person meetings showcasing unblinded data, webinars, site visits). Eighteen of the MI-Collaborative hospitals received additional support to implement recommended pneumonia prevention practices ("MI-CollaborativePlus"), whereas 15 did not ("MI-CollaborativeOnly"). We evaluated rates of postoperative pneumonia, adjusting for patient mix and hospital effects. Baseline patient characteristics were qualitatively similar between groups and time. During the preintervention period (Q3/2011 through Q3/2012), there was no statistically significant difference in the adjusted odds of pneumonia for STS hospitals participating in the MI-Collaborative compared to the STS non-MI hospitals. However, during the intervention period (Q4/2012 through Q2/2017), there was a significant 2% reduction per quarter in the adjusted odds of pneumonia for MI-Collaborative hospitals (n=33) relative to the STS-nonMI hospitals. There was a significant 3% per quarter reduction in the adjusted odds of pneumonia for the MI-CollaborativeOnly (n=15) hospitals relative to the STS-nonMI hospitals. Over the course of the overall study period, the STS-nonMI hospitals had a 1.96% reduction in risk-adjusted pneumonia (pre- vs. intervention periods), which was less than the MI-Collaborative (3.23%, P=0.011). Over the same time period, the MI-CollaborativePlus (n=18) reduced adjusted pneumonia rates by 10.29%, P=0.001.

CONCLUSIONS

Participation in a physician-led collaborative was associated with significant reductions in pneumonia relative to a national quality reporting program. Interventions including collaborative learning may yield superior outcomes relative to solely using physician feedback reporting.

CLINICAL TRIAL REGISTRATION

URL: https://www.clinicaltrials.gov . Unique identifier: NCT02068716.

Urinary Catheter-Associated Infections

Catheter-associated urinary tract infection remains one of the most prevalent, yet preventable, health care-associated infections. General prevention strategies include strict adherence to hand hygiene and antimicrobial stewardship. Duration of urinary catheterization is the most important modifiable risk factor. Targeted prevention strategies include limiting urinary catheter use; physician reminder systems, nurse-initiated discontinuation protocols, and automatic stop orders have successfully decreased catheter duration. Alternatives should be considered. If catheterization is necessary, proper aseptic practices for insertion and maintenance and closed catheter collection systems are essential for prevention. The use of bladder bundles and collaboratives aids in the effective implementation of prevention measures.

Urinary Tract Infections

Catheter-associated urinary tract infection (CAUTI) remains one of the most prevalent, yet preventable, health care-associated infections and predominantly occurs in patients with indwelling urinary catheters. Targeted strategies for prevention of CAUTI include limiting urinary catheter use; physician reminder systems, nurse-initiated discontinuation protocols, and automatic stop orders have successfully decreased catheter duration. Alternatives to indwelling catheters should be considered in appropriate patients. If indwelling catheterization is necessary, proper aseptic practices for catheter insertion and maintenance and closed catheter collection system is essential for preventing CAUTI. The use of "bladder bundles" and collaboratives aids in the effective implementation of CAUTI prevention measures.

Effect of an antimicrobial stewardship intervention on outcomes for patients with Clostridium difficile infection

BACKGROUND

Although antimicrobial stewardship programs (ASPs) are uniquely positioned to improve treatment of Clostridium difficile infection (CDI) through targeted interventions, studies to date have not rigorously evaluated the influence of ASP involvement on clinical outcomes attributed to CDI.

METHODS

We performed a quasiexperimental study of adult patients with CDI before (n = 307) and after (n = 285) a real-time ASP review was initiated. In the intervention group, an ASP pharmacist was notified of positive CDI results and consulted with the care team to initiate optimal therapy, minimize concomitant antibiotic and acid-suppressive therapy, and recommend surgical/infectious diseases consultation in complicated cases. The primary outcome was a composite of attributable 30-day mortality, intensive care unit admission, colectomy/ileostomy, and recurrence.

RESULTS

A higher percentage of patients in the ASP intervention group had acid-suppressive therapy discontinued (30% vs 13%; P < .01). Among patients with severe CDI, more patients in the intervention group received an infectious diseases consultation (17% vs 10%; P = .04), received appropriate therapy with oral vancomycin (87% vs 59%; P <.01), and vancomycin was initiated earlier (mean, 1.1 vs 1.7 days; P <.01). Incidence of the composite outcome was not significantly different between the 2 groups (12.3% vs 14.7%; P = .40).

CONCLUSIONS

ASP review and intervention improved CDI process measures. A decrease in composite outcomes was not found, which may be due to low baseline rates of attributable complications in our institution.

Ventilator-Associated Pneumonia in the Home Care Setting

Objective.

To describe the rate of infection, associated organisms, and potential risk factors for ventilator-associated pneumonia (VAP) in patients receiving mechanical ventilation at home.

Design.

Retrospective cohort study.

Setting.

University-affiliated home care service.

Patients.

Patients receiving mechanical ventilation at home from June 1995 through December 2001.

Results.

Fifty-seven patients underwent ventilation at home for a total of 50,762 ventilator-days (mean ± SD, 890.6 ± 644.43 days; range, 76-2,458 days). Seventy-nine episodes of VAP occurred in 27 patients (rate, 1.55 episodes per 1,000 ventilator-days). The first episode of VAP occurred after a mean (±SD) of 245 ± 318.07 ventilator-days. VAP was most common during the first 500 days of ventilation. Rates of VAP were higher among patients who required ventilation for longer daily durations, compared with those who required it for shorter daily durations. There was no association of VAP with age, sex, underlying disease, reason for ventilation, antacid therapy, or steroid use. Microorganisms isolated from 33 episodes of VAP with available culture results included Pseudomonas species (17 isolates), Staphylococcus aureus (11), Serratia species (7), and Stenotrophomonas species (5). Eight patients died during the study; no deaths were attributed to pneumonia.

Conclusions.

Although the organisms associated with VAP in the home setting are similar to those associated with hospital-acquired VAP, the incidence and mortality is much lower in the home care setting. Interventions to reduce the risk of VAP among patients receiving home care should be focused on patients who require ventilation for longer daily durations or who are new to receiving mechanical ventilation at home.

Analysis of Central Line–Associated Bloodstream Infections in the Intensive Care Unit after Implementation of Central Line Bundles

Central line-associated bloodstream infections (CLABSIs) have been reduced in number but not eliminated in our intensive care units with use of central line bundles. We performed an analysis of remaining CLABSIs. Many bloodstream infections that met the definition of CLABSI had sources other than central lines or represented contaminated blood samples.

Epidemiology of Hospital-Acquired Urinary Tract–Related Bloodstream Infection at a University Hospital

Little is known about the epidemiology of nosocomial urinary tract-related bloodstream infection. In a case series from an academic medical center,Enterococcus(28.7%) andCandida(19.6%) species were the predominant microorganisms, which suggests a potential shift from gram-negative microorganisms. A case-fatality rate of 32.8% highlights the severity of this condition.

Baseline measure of alcohol-based skin preparation agents before 2011 National Quality Forum recommendation in a general surgery population

The National Quality Forum (2011) recommends the use of alcohol-based skin preparation agents before surgery to help prevent infections. This multihospital study (n = 3,794) evaluates its use in a general surgery patient population before the National Quality Forum recommendation. Forty-seven percent of cases received an alcohol-based skin preparation agent.

Impact of postplacement adjustment of peripherally inserted central catheters on the risk of bloodstream infection and venous thrombus formation

OBJECTIVE

Peripherally inserted central catheter (PICC) tip malposition is potentially associated with complications, and postplacement adjustment of PICCs is widely performed. We sought to characterize the association between central line-associated bloodstream infection (CLABSI) or venous thrombus (VT) and PICC adjustment.

DESIGN

Retrospective cohort study.

SETTING

University of Michigan Health System, a large referral hospital.

PATIENTS

Patients who had PICCs placed between February 2007 and August 2007.

METHODS

The primary outcomes were development of CLABSI within 14 days or VT within 60 days of postplacement PICC adjustment, identified by review of patient electronic medical records.

RESULTS

There were 57 CLABSIs (2.69/1,000 PICC-days) and 47 VTs (1.23/1,000 PICC-days); 609 individuals had 1, 134 had 2, and 33 had 3 or more adjustments. One adjustment was protective against CLABSI (P=.04), whereas 2 or 3 or more adjustments had no association with CLABSI (P=.58 and .47, respectively). One, 2, and 3 or more adjustments had no association with VT formation (P=.59, .85, and .78, respectively). Immunosuppression (P<.01), power-injectable PICCs (P=.05), and 3 PICC lumens compared with 1 lumen (P=.02) were associated with CLABSI. Power-injectable PICCs were also associated with increased VT formation (P=.03).

CONCLUSIONS

Immunosuppression and 3 PICC lumens were associated with increased risk of CLABSI. Power-injectable PICCs were associated with increased risk of CLABSI and VT formation. Postplacement adjustment of PICCs was not associated with increased risk of CLABSI or VT.

Emergence of Carbapenemaseproducing Klebsiella Pneumoniae of Sequence type 258 in Michigan, USA

The prevalence of carbapenemase-producing Enterobacteriaceae (CPE) in our hospital increased beginning in 2009. We aimed to study the clinical and molecular epidemiology of these emerging isolates. We performed a retrospective review of all adult patients with clinical cultures confirmed as CPE by positive modified Hodge test from 5/2009- 5/2010 at the University of Michigan Health System (UMHS). Clinical information was obtained from electronic medical records. Available CPE isolates were analyzed by polymerase chain reaction (PCR) and sequencing of the 16S rRNA encoding gene and bla KPC locus. Multilocus sequence typing (MLST) was used to characterize Klebsiella pneumoniae isolates. Twenty six unique CPE isolates were obtained from 25 adult patients. The majority were Klebsiella pneumoniae (n=17). Other isolates included K. oxytoca (n=3), Citrobacter freundii (n=2), Enterobacter cloacae (n=2), Enterobacter aerogenes (n=1) and Escherichia coli (n=1). Molecular characterization of 19 available CPE isolates showed that 13 (68%) carried the KPC-3 allele and 6 (32%) carried the KPC-2 allele. Among 14 available K. pneumoniae strains, 12 (86%) carried the KPC-3 allele and belonged to a common lineage, sequence type (ST) 258. The other 2 (14%) K. pneumoniae isolates carried the KPC-2 allele and belonged to two unique STs. Among these ST 258 strains, 67% were isolated from patients with prior exposures to health care settings outside of our institution. In contrast, all CPE isolates carrying the KPC-2 allele and all non ST 258 CPE isolates had acquisition attributable to our hospital. Molecular epidemiology of carbapenemase producing K. pneumoniae suggests that KPC-3 producing K. pneumoniae isolates of a common lineage, sequence type (ST 258), are emerging in our hospital. While ST 258 is a dominant sequence type throughout the United States, this study is the first to report its presence in Michigan.

Accuracy of hospital administrative data in reporting central line-associated bloodstream infections in newborns

OBJECTIVES

Central line-associated bloodstream infections (CLABSIs) are a significant source of morbidity and mortality in the NICU. In 2010, Medicaid was mandated not to pay hospitals for treatment of CLABSI; however, the source of CLABSI data for this policy was not specified. Our objective was to evaluate the accuracy of hospital administrative data compared with CLABSI confirmed by an infection control service.

METHODS

We evaluated hospital administrative and infection control data for newborns admitted consecutively from January 1, 2008, to December 31, 2010. Clinical and demographic data were collected through chart review. We compared cases of CLABSI identified by administrative data (International Classification of Diseases, Ninth Revision, Clinical Modification 999.31) with infection control data that use national criteria from the Centers for Disease Control and Prevention as the gold standard. To ascertain the nature possible deficiencies in the administrative data, each patient's medical record was searched to determine if clinical phrases that commonly refer to CLABSI appeared.

RESULTS

Of 2920 infants admitted to the NICU during our study period, 52 were identified as having a CLABSI: 42 by infection control data only, 7 through hospital administrative data only, and 3 appearing in both. Against the gold standard, hospital administrative data were 6.7% sensitive and 99.7% specific, with a positive predictive value of 30.0% and a negative predictive value of 98.6%. Only 48% of medical records indicated a CLABSI.

CONCLUSIONS

Our findings from a major children's hospital NICU indicate that International Classification of Diseases, Ninth Revision, Clinical Modification code 993.31 is presently not accurate and cannot be used reliably to compare CLABSI rates in NICUs.

Predictors of hospital-acquired urinary tract-related bloodstream infection

OBJECTIVE

Bloodstream infection (BSI) secondary to nosocomial urinary tract infection is associated with substantial morbidity, mortality, and additional financial costs. Our objective was to identify predictors of nosocomial urinary tract-related BSI.

DESIGN

Matched case-control study.

SETTING

Midwestern tertiary care hospital.

PATIENTS

Cases (n=298) were patients with a positive urine culture obtained more than 48 hours after admission and a blood culture obtained within 14 days of the urine culture that grew the same organism. Controls (n=667), selected by incidence density sampling, included patients with a positive urine culture who were at risk for BSI but did not develop one. Methods. Conditional logistic regression and classification and regression tree analyses.

RESULTS

The most frequently isolated microorganisms that spread from the urinary tract to the bloodstream were Enterococcus species. Independent risk factors included neutropenia (odds ratio [OR], 10.99; 95% confidence interval [CI], 5.78-20.88), renal disease (OR, 2.96; 95% CI, 1.98-4.41), and male sex (OR, 2.18; 95% CI, 1.52-3.12). The probability of developing a urinary tract-related BSI among neutropenic patients was 70%. Receipt of immunosuppressants (OR, 1.53; 95% CI, 1.04-2.25), insulin (OR, 4.82; 95% CI, 2.52-9.21), and antibacterials (OR, 0.66; 95% CI, 0.44-0.97) also significantly altered risk.

CONCLUSIONS

The heightened risk of urinary tract-related BSI associated with several comorbid conditions suggests that the management of nosocomial bacteriuria may benefit from tailoring to certain patient subgroups. Consideration of time-dependent risk factors, such as medications, may also help guide clinical decisions in reducing BSI.

Preoperative topical antimicrobial decolonization in head and neck surgery

OBJECTIVES/HYPOTHESIS

Surgical site infections (SSIs) are an important cause of morbidity and mortality after head and neck surgery. Our primary objective was to determine the efficacy of preoperative topical antimicrobial decolonization before head and neck surgery.

STUDY DESIGN

Prospective, randomized controlled trial.

METHODS

This study was conducted among 84 patients presenting for head and neck surgery requiring admission to an academic medical center. Preoperative cultures were performed to identify Staphylococcus aureus carriers. Patients were randomized to preoperative topical antimicrobial decolonization with a 5-day regimen of chlorhexidine skin rinses and intranasal mupirocin coupled with standard perioperative systemic antimicrobial prophylaxis, versus standard prophylaxis alone. The main outcome was the incidence of SSIs.

RESULTS

Despite a trend suggesting a decrease in SSIs with perioperative topical antimicrobial decolonization (24% vs. 10%), there was no significant difference (odds ratio, 0.34; 95% confidence interval, 0.10-1.18; P = .079). Patients with a higher American Society of Anesthesiologists score (3 vs. 1; P = .02), with more operative blood loss (P = .05), and who required operative takeback (P = .04) had a higher rate of SSIs; there was a trend suggesting a higher rate of SSIs among patients undergoing clean-contaminated surgery compared to clean cases (P = .08) and among those having received prior radiation (P = .07) or chemotherapy (P = .06).

CONCLUSIONS

Preoperative antimicrobial decolonization did not significantly decrease the incidence of SSIs after head and neck surgery, but might be considered for high-risk groups despite the lack of conclusive evidence confirming efficacy. Risk factors for SSIs after head and neck surgery are identified for the first time in a prospective study.

Higher rates of Clostridium difficile infection among smokers

Objectives

Cigarette smoking has been shown to be related to inflammatory bowel disease. We investigated whether smoking affected the probability of developing Clostridium difficile infection (CDI).

Methods

We conducted a longitudinal study of 16,781 older individuals from the nationally representative Health and Retirement Study. Data were linked to files from the Centers for Medicare and Medicaid Services.

Results

Overall, the rate of CDI in older individuals was 220.6 per 100,000 person-years (95% CI 193.3, 248.0). Rates of CDI were 281.6/100,000 person-years in current smokers, 229.0/100,000 in former smokers and 189.1/100,000 person-years in never smokers. The odds of CDI were 33% greater in former smokers (95% CI: 8%, 65%) and 80% greater in current smokers (95% CI: 33%, 145%) when compared to never smokers. When the number of CDI-related visits was evaluated, current smokers had a 75% increased rate of CDI compared to never smokers (95% CI: 15%, 167%).

Conclusions

Smoking is associated with developing a Clostridium difficile infection. Current smokers have the highest risk, followed by former smokers, when compared to rates of infection in never smokers.

Reuse of medical devices: implications for infection control

Reuse of both single-use and multiuse medical devices is a common practice and can result in transmission of infection when appropriate sterilization or reprocessing does not occur. Reuse of single-use devices can be problematic because there are no clear standards for reprocessing, although data regarding adverse outcomes are limited. Single-use devices are commonly reused, appropriately or inappropriately, in resource-limited settings because of cost constraints. Reuse of medical devices raises important legal and ethical questions.

Epidemiology of hospital-acquired urinary tract-related bloodstream infection at a university hospital

Little is known about the epidemiology of nosocomial urinary tract-related bloodstream infection. In a case series from an academic medical center, Enterococcus (28.7%) and Candida (19.6%) species were the predominant microorganisms, which suggests a potential shift from gram-negative microorganisms. A case-fatality rate of 32.8% highlights the severity of this condition.

Evaluation of hospital room assignment and acquisition of Clostridium difficile infection

BACKGROUND AND OBJECTIVE

Clostridium difficile spores persist in hospital environments for an extended period. We evaluated whether admission to a room previously occupied by a patient with C. difficile infection (CDI) increased the risk of acquiring CDI.

DESIGN

Retrospective cohort study.

SETTING

Medical intensive care unit (ICU) at a tertiary care hospital.

METHODS

Patients admitted from January 1, 2005, through June 30, 2006, were evaluated for a diagnosis of CDI 48 hours after ICU admission and within 30 days after ICU discharge. Medical, ICU, and pharmacy records were reviewed for other CDI risk factors. Admitted patients who did develop CDI were compared with admitted patients who did not.

RESULTS

Among 1,844 patients admitted to the ICU, 134 CDI cases were identified. After exclusions, 1,770 admitted patients remained for analysis. Of the patients who acquired CDI after admission to the ICU, 4.6% had a prior occupant without CDI, whereas 11.0% had a prior occupant with CDI (P = .002). The effect of room on CDI acquisition remained a significant risk factor (P = .008) when Kaplan-Meier curves were used. The prior occupant's CDI status remained significant (p = .01; hazard ratio, 2.35) when controlling for the current patient's age, Acute Physiology and Chronic Health Evaluation III score, exposure to proton pump inhibitors, and antibiotic use.

CONCLUSIONS

A prior room occupant with CDI is a significant risk factor for CDI acquisition, independent of established CDI risk factors. These findings have implications for room placement and hospital design.

Urinary tract infections

Catheter-associated urinary tract infections (CAUTIs) account for approximately 40% of all health care-associated infections. Despite studies showing benefit of interventions for prevention of CAUTI, adoption of these practices has not occurred in many healthcare facilities in the United States. As urinary catheters account for the majority of healthcare-associated UTIs, the most important interventions are directed at avoiding placement of urinary catheters and promoting early removal when appropriate. Alternatives to indwelling catheters such as intermittent catheterization and condom catheters should be considered. If indwelling catheterization is appropriate, proper aseptic practices for catheter insertion and maintenance and use of a closed catheter collection system are essential for preventing CAUTI. The use of antimicrobial catheters also may be considered when the rates of CAUTI remain persistently high despite adherence to other evidence-based practices, or in patients deemed to be at high risk for CAUTI or its complications. Attention toward prevention of CAUTI will likely increase as Center for Medicare and Medicaid Services and other third-party payers no longer reimburse for hospital-acquired UTI.

Pseudo-outbreak of Clostridium sordellii infection following probable cross-contamination in a hospital clinical microbiology laboratory

We report a pseudo-outbreak of infection caused by Clostridium sordellii, an uncommon human pathogen. The pseudo-outbreak involved 6 patients and was temporally associated with a change by the clinical microbiology laboratory in the protocol of handling anaerobic culture specimens. All isolates were genetically indistinguishable from a laboratory reference strain used for quality control.

A polyurethane cuffed endotracheal tube is associated with decreased rates of ventilator-associated pneumonia

PURPOSE

The aim of this study was to determine whether the use of a polyurethane-cuffed endotracheal tube would result in a decrease in ventilator-associated pneumonia rate.

MATERIALS AND METHODS

We replaced conventional endotracheal tube with a polyurethane-cuff endotracheal tube (Microcuff, Kimberly-Clark Corporation, Rosewell, Ga) in all adult mechanically ventilated patients throughout our large academic hospital from July 2007 to June 2008. We retrospectively compared the rates of ventilator-associated pneumonia before, during, and after the intervention year by interrupted time-series analysis.

RESULTS

Ventilator-associated pneumonia rates decreased from 5.3 per 1000 ventilator days before the use of the polyurethane-cuffed endotracheal tube to 2.8 per 1000 ventilator days during the intervention year (P = .0138). During the first 3 months after return to conventional tubes, the rate of ventilator-associated pneumonia was 3.5/1000 ventilator days. Use of the polyurethane-cuffed endotracheal tube was associated with an incidence risk ratio of ventilator-associated pneumonia of 0.572 (95% confidence interval, 0.340-0.963). In statistical regression analysis controlling for other possible alterations in the hospital environment, as measured by rate of tracheostomy-ventilator-associated pneumonia, the incidence risk ratio of ventilator-associated pneumonia in patients intubated with polyurethane-cuffed endotracheal tube was 0.565 (P = .032; 95% confidence interval, 0.335-0.953).

CONCLUSIONS

Use of a polyurethane-cuffed endotracheal tube was associated with a significant decrease in the rate of ventilator-associated pneumonia in our study.

Mycobacterium neoaurum bloodstream infection: report of 4 cases and review of the literature

We describe a cluster of 4 bloodstream infections with Mycobacterium neoaurum and 5 additional cases from the literature. Infections occurred mainly in immunocompromised hosts who had central venous catheters. Fever was universal at presentation, but local signs of inflammation were rare. Combination antimicrobial therapy and catheter removal resulted in clinical cure.

Are antiseptic-coated central venous catheters effective in a real-world setting?

BACKGROUND

Catheter-related bloodstream infections are common, costly, and morbid. Randomized controlled trials indicate that antiseptic-coated central venous catheters reduce infection rates.

OBJECTIVE

To assess the clinical and economic effectiveness of antiseptic-coated catheters for critically ill patients in a real-world setting.

METHODS

Central venous catheters coated with chlorhexidine/silver-sulfadiazene were introduced in all patients requiring central venous access in adult intensive care units at the University of Michigan Health System, a large, tertiary care teaching hospital. A pretest-posttest cohort design measured the primary outcome of catheter-related bloodstream infection rate, comparing the 2 years prior to the intervention with the 2 years following the intervention. We also evaluated cost-effectiveness and changes in vancomycin use.

RESULTS

The intervention was associated with a 4% per month relative reduction in the incidence of catheter-related bloodstream infection, after controlling for the effects of time. Overall, a 35% relative risk reduction (P < .0003) in the catheter-related bloodstream infection rate occurred in the posttest phase. The use of antiseptic-coated catheters reduced costs more than $100,000 annually. Vancomycin use was less in units in which antiseptic catheters were used compared with wards in which these catheters were not used.

CONCLUSION

Antiseptic-coated catheters appear to be clinically effective and economically efficient in a real-world setting.

Vancomycin-resistant enterococcal colonization and infection in liver transplant candidates and recipients: a prospective surveillance study

BACKGROUND

Vancomycin-resistant enterococcal (VRE) infections cause significant morbidity and mortality among patients undergoing liver transplantation. We performed a prospective study among patients awaiting transplantation to assess rates, risk factors, and outcomes associated with VRE colonization before and after transplantation.

METHODS

All adults on the transplantation waiting list from 2000-2003 were eligible. Demographic, historical, and laboratory data, as well as stool samples to be analyzed for VRE, were collected at enrollment and every 4-6 months thereafter until transplantation. After transplantation, samples were obtained every 3 days during hospitalization and were analyzed for VRE; outcomes were assessed at 90 days.

RESULTS

Overall, 375 patients were enrolled in our study, and 142 received transplants. VRE colonization occurred in 50 (13%) of 375 patients before transplantation and was independently associated with treatment with antianaerobic antimicrobials, third-generation cephalosporins, proton pump inhibitors, or neomycin; having a recent endoscopic retrograde cholangiopancreatogram or paracentesis procedure; and admission to the liver unit. Of these 50 patients, 22 (44%) received a transplant, and 7 (32%) of 22 developed a VRE infection after transplantation. An additional 22 patients (18%) who were not colonized before transplantation acquired VRE after transplantation; VRE infection developed in 5 (23%) of these patients. Patients colonized with VRE either before or after transplantation had longer stays in the intensive care unit and the hospital. Mortality at 90 days was significantly greater among those who acquired VRE after transplantation (5 [23%] of 22), compared with those who had VRE colonization before transplantation (2 [9%] of 22).

CONCLUSIONS

Liver transplantation candidates with VRE colonization before transplantation experience greater morbidity but not greater mortality, compared with noncolonized candidates. Transplant recipients who acquire VRE after transplantation have a higher mortality rate than noncolonized recipients. Strategies should be implemented to reduce nosocomial VRE acquisition after transplantation among this vulnerable group.

A reminder reduces urinary catheterization in hospitalized patients

BACKGROUND

Indwelling urinary catheters are placed in up to 25% of hospitalized patients and are a leading cause of hospital-acquired infection. Duration of catheterization is the dominant risk factor for hospital-acquired urinary tract infection. Physicians are often unaware that their patients have a urinary catheter, and these "forgotten" catheters are frequently unnecessary.

METHODS

A controlled trial, using a pretest-posttest design, was conducted on four hospital wards at an academic medical center. A simple written reminder was designed to aid the hospitalized patient's team in remembering that the patient had a urinary catheter. Two of the four wards were assigned to the intervention group, and two served as controls. A research nurse monitored the urethral catheter status of each patient daily.

RESULTS

A total of 5,678 subjects were evaluated. After adjusting for age, sex, and length of stay, the average proportion of time patients were catheterized increased by 15.1% in the control group but decreased by 7.6% in the intervention group in the intention-to-treat analysis (p = .007). There was no significant difference in urethral recatheterizations between intervention and control groups. The hospital cost savings provided by the intervention offset the necessary costs of this nurse-based intervention. CONCLUSIORN: In the approximately 90% of U.S. hospitals currently without computerized order-entry systems, a written reminder should be considered as one method for improving the safety of hospitalized patients.

Disseminated Scedosporium apiospermum infection in a previously healthy woman with HELLP syndrome

A previously healthy 33-year-old female died of disseminated infection with Scedosporium apiospermum in association with Hemolysis, Elevated Liver enzymes, and Low Platelets (HELLP) syndrome following the delivery of twins. Her postpartum course was complicated by multisystem organ failure managed with extracorporeal membrane oxygenation (ECMO). She also developed bowel and left lower extremity ischemia requiring surgical resection. Blood cultures yielded S. apiospermum, and histologic findings revealed in vivo adventitious sporulation, an unusual occurrence with this pathogen. Autopsy showed extensive fungal infection of brain, lungs, thyroid, heart, and kidneys.

Successful treatment of vancomycin resistant enterococcus faecium mediastinitis associated with left ventricular assist devices

We present 2 cases of vancomycin-resistant Enterococcus faecium mediastinitis associated with left ventricular assist devices in the setting of heart transplantation. Despite complicated operative courses and deep infection secondary to antimicrobial resistant organisms, both patients were successfully treated and have remained infection free in the long term.

Aeromonas infection of the hepatobiliary system: report of 15 cases and review of the literature

Aeromonas species cause both intestinal and extraintestinal disease. We reviewed hospital laboratory and medical records to identify patients with Aeromonas infection of the hepatobiliary or pancreatic system. Analysis of data from our hospital, as well as a review of the published literature, yielded a total of 41 episodes in 39 patients, and the features of these episodes are described. The most common manifestation of Aeromonas hepatobiliary infection among all reported cases was cholangitis (29 of 41 episodes). The majority of infections in our hospital occurred in patients with underlying immunosuppression or malignancy (13 of 15 patients), including 4 liver transplant recipients, and nosocomial infection was not infrequent (8 of 17 episodes). Infection occurred most commonly in patients with obstruction of the biliary tract due to stones, tumor, or stricture and was associated with a relatively high mortality rate (11.8%). Antibiotic susceptibility testing revealed that gentamicin, imipenem, and ciprofloxacin had the highest activity against the Aeromonas species isolated.

Biofilms and catheter-associated urinary tract infections

Urinary catheter-related infections are commonly seen in several different patient populations and lead to substantial morbidity. The overall health care costs caused by these infections are sizable given how often urinary catheters are used in acute care settings, extended care facilities, and in persons with injured spinal cords. Recent attention has appropriately focused on biofilm development on the catheter surface because biofilm has important implications for the pathogenesis, treatment, and prevention of catheter-related infection. Because the most important risk factor for infection is duration of catheterization, indwelling urethral catheterization should be avoided or at least limited whenever possible. Additional methods to prevent this infection include aseptic insertion and maintenance use of a closed drainage system, anti-infective catheters in patients at high-risk for infection, and systemic antibiotics in select patients. Alternative urinary collection strategies may be appropriate in certain patient groups. Specifically, condom catheters should be considered in men likely to be adherent with this urinary collection method, suprapubic catheters should be considered in patients requiring long-term indwelling drainage, and intermittent catheterization seems appropriate in patients with injured spinal cords. Future research should focus on additional methods for preventing this common infection.

A retrospective review of three antibiotic prophylaxis regimens for pediatric cardiac surgical patients

BACKGROUND

Optimal antimicrobial prophylaxis for the pediatric cardiac surgical patient is unknown. We have reviewed our experience with more than 4,000 pediatric cardiac surgical patients at the University of Michigan to evaluate antibiotic prophylaxis regimens.

METHODS

Three antibiotic prophylaxis protocols were serially used during a 6-year period: Protocol 1 (n = 786): cefazolin was administered before operation and continued as long as thoracostomy tubes or central venous catheters were present; Protocol 2 (n = 1095): cefazolin was discontinued 48 hours postoperatively, regardless of the presence of tubes or catheters; Protocol 3 (n = 2039): cefazolin was continued as long as thoracostomy tubes were present, but not for central venous catheters. Patients with an open chest postoperatively received vancomycin and gentamicin until chest closure. This was identical during all three protocols. We retrospectively determined the rate of surgical site infections and unrelated bloodstream infections (the latter for both cardiac medical and surgical patients) for the three protocols.

RESULTS

Surgical site infections per 100 operations for protocols 1, 2, and 3 was 2.04, 6.58, and 1.67, respectively (p < 0.05 for protocol 2 versus protocols 1 and 3). The mean age of patients with a surgical site infection ranged from 12 to 15.4 months. Patients with an open chest had a higher rate of surgical site infection (18.8% for protocol 2 and 9.3% for protocol 3). Bloodstream infections per 1,000 patient days for protocols 1, 2, and 3 were 2.18, 6.51, and 5.02, respectively (p < 0.05 protocol 1 versus protocols 2 and 3).

CONCLUSIONS

These data suggest that pediatric cardiac surgical patients may benefit from prophylactic antibiotics as long as thoracostomy tubes are in place.

Nosocomial infections in left ventricular assist device recipients

Infection remains a serious complication of left ventricular assist device (LVAD) implantation. We performed a cohort study to assess infections among patients who underwent LVAD implantation from October 1996 through May 1999. Thirty-six LVADs were implanted in 35 patients; the mean duration (+/- standard deviation) of LVAD use was 73+/-60 days (total for all patients, 2565 days). Sixteen patients developed surgical site infections (SSIs; rate, 6.2 infections per 1000 LVAD days); 9 were deep-tissue or organ/space infections and 7 were superficial. Other infections included 7 cases of pneumonia (rate, 2.7 cases per 1000 LVAD days), 6 venous infections (rate, 2.3 per 1000 LVAD days), 2 bloodstream infections (rate, cases 0.8 per 1000 LVAD days), 3 urinary tract infections, and 2 skin and soft-tissue infections. Deep SSIs were associated with the requirement for postoperative hemodialysis (P=.02). Overall use of antibiotics was extensive, and a trend toward infection with antibiotic-resistant organisms was noted. Infections were a frequent complication of LVAD implantation. Further studies of interventions for preventing infection in LVAD recipients are warranted.

Antimicrobial resistance in Streptococcus pneumoniae: implications for patients with community-acquired pneumonia

Streptococcus pneumoniae is the leading cause of community-acquired pneumonia. During the past decade, the prevalence of penicillin resistance in S pneumoniae has increased dramatically, with resistance rates approaching 45% in some areas of the United States. Streptococcus pneumoniae has also acquired resistance to other commonly used antimicrobials, including cephalosporins, macrolides, and trimethoprim-sulfamethoxazole. While vancomycin and the newer quinolones are currently highly active against most strains of S pneumoniae, reduced susceptibilities to these agents have been identified in some strains. Prior use of antimicrobial agents is the major risk factor for colonization and infection with antibiotic-resistant strains. beta-Lactam antibiotics remain the treatment of choice for infections caused by susceptible S pneumoniae. The optimum therapy for penicillin-resistant strains remains unclear. Appropriate empirical therapy for patients with community-acquired pneumonia depends in part on the community-specific resistance patterns of S pneumoniae to various antibiotics. In this article, we provide an overview of the development of S pneumoniae resistance to commonly used antibiotics and discuss the implications of the development of resistance on treatment decisions.

Nosocomial infections in adult patients undergoing extracorporeal membrane oxygenation

The use of extracorporeal membrane oxygenation (ECMO) for adult patients has increased in recent years. A retrospective cohort study of adult patients undergoing ECMO was performed between 19 February 1985 and 10 October 1995 to evaluate nosocomial infections. Seventy-one evaluable patients underwent ECMO for a total of 799 days. Forty-six infections were identified in 32 (45%) of 71 patients. There were 15 bloodstream infections, 13 lower respiratory infections, 11 urinary tract infections, and 7 miscellaneous infections. The rates of bloodstream infection (18.8 cases per 1,000 ECMO days) and urinary tract infection (13.8 cases per 1,000 ECMO days) were significantly higher than those reported through the Centers for Disease Control and Prevention / National Nosocomial Infection Surveillance System (P < .0001 and P < .001, respectively). The rate of bloodstream infection increased with the duration of ECMO cannulation. This study highlights the increased risk for nosocomial infections in this patient population. Infection may not be apparent, and increased physician awareness of infection risk is imperative.

Donor-to-recipient transmission of bacteria as an unusual cause of mediastinitis in a heart transplant recipient

We present a 54-year-old male heart transplant recipient who developed mediastinitis caused by Klebsiella oxytoca and Veillonella species. Culture of the donor's bronchus also grew K. oxytoca and a Veillonella species. Pulsed-field gel electrophoresis revealed that the K. oxytoca isolates had identical banding patterns. This case illustrates transmission of pathogenic bacteria via a contaminated organ.

Postexposure chemoprophylaxis for occupational exposure to HIV in the dental office

Occupational exposure to HIV continues to be a concern for health care workers. Preventing exposure through the use of universal precautions is the primary means of protection. New Public Health Service interagency work group recommendations for postexposure chemoprophylaxis provide information to help manage occupational exposure to HIV.