Julie Lankiewicz

Targeted versus Universal Decolonization to Prevent ICU Infection

BACKGROUND Both targeted decolonization and universal decolonization of patients in intensive care units (ICUs) are candidate strategies to prevent health care-associated infections, particularly those caused by methicillin-resistant Staphylococcus aureus (MRSA). METHODS We conducted a pragmatic, cluster-randomized trial. Hospitals were randomly assigned to one of three strategies, with all adult ICUs in a given hospital assigned to the same strategy. Group 1 implemented MRSA screening and isolation; group 2, targeted decolonization (i.e., screening, isolation, and decolonization of MRSA carriers); and group 3, universal decolonization (i.e., no screening, and decolonization of all patients). Proportional-hazards models were used to assess differences in infection reductions across the study groups, with clustering according to hospital. RESULTS A total of 43 hospitals (including 74 ICUs and 74,256 patients during the intervention period) underwent randomization. In the intervention period versus the baseline period, modeled hazard ratios for MRSA clinical isolates were 0.92 for screening and isolation (crude rate, 3.2 vs. 3.4 isolates per 1000 days), 0.75 for targeted decolonization (3.2 vs. 4.3 isolates per 1000 days), and 0.63 for universal decolonization (2.1 vs. 3.4 isolates per 1000 days) (P=0.01 for test of all groups being equal). In the intervention versus baseline periods, hazard ratios for bloodstream infection with any pathogen in the three groups were 0.99 (crude rate, 4.1 vs. 4.2 infections per 1000 days), 0.78 (3.7 vs. 4.8 infections per 1000 days), and 0.56 (3.6 vs. 6.1 infections per 1000 days), respectively (P<0.001 for test of all groups being equal). Universal decolonization resulted in a significantly greater reduction in the rate of all bloodstream infections than either targeted decolonization or screening and isolation. One bloodstream infection was prevented per 54 patients who underwent decolonization. The reductions in rates of MRSA bloodstream infection were similar to those of all bloodstream infections, but the difference was not significant. Adverse events, which occurred in 7 patients, were mild and related to chlorhexidine. CONCLUSIONS In routine ICU practice, universal decolonization was more effective than targeted decolonization or screening and isolation in reducing rates of MRSA clinical isolates and bloodstream infection from any pathogen. (Funded by the Agency for Healthcare Research and the Centers for Disease Control and Prevention; REDUCE MRSA ClinicalTrials.gov number, NCT00980980).

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).

Enhanced Surgical Site Infection Surveillance Following Hysterectomy, Vascular, and Colorectal Surgery

OBJECTIVE To evaluate the use of inpatient pharmacy and administrative data to detect surgical site infections (SSIs) following hysterectomy and colorectal and vascular surgery. DESIGN Retrospective cohort study. SETTING Five hospitals affiliated with academic medical centers. PATIENTS Adults who underwent abdominal or vaginal hysterectomy, colorectal surgery, or vascular surgery procedures between July 1, 2003, and June 30, 2005. METHODS We reviewed the medical records of weighted, random samples drawn from 3,079 abdominal and vaginal hysterectomy, 4,748 colorectal surgery, and 3,332 vascular surgery procedures. We compared routine surveillance with screening of inpatient pharmacy data and diagnosis codes and then performed medical record review to confirm SSI status. RESULTS Medical records from 823 hysterectomy, 736 colorectal surgery, and 680 vascular surgery procedures were reviewed. SSI rates determined by antimicrobial- and/or diagnosis code-based screening followed by medical record review (enhanced surveillance) were substantially higher than rates determined by routine surveillance (4.3% [95% confidence interval, 3.6%-5.1%] vs 2.7% for hysterectomies, 7.1% [95% confidence interval, 6.7%-8.2%] vs 2.0% for colorectal procedures, and 2.3% [95% confidence interval, 1.9%-2.9%] vs 1.4% for vascular procedures). Enhanced surveillance had substantially higher sensitivity than did routine surveillance to detect SSI (92% vs 59% for hysterectomies, 88% vs 22% for colorectal procedures, and 72% vs 43% for vascular procedures). A review of medical records confirmed SSI for 31% of hysterectomies, 20% of colorectal procedures, and 31% of vascular procedures that met the enhanced screening criteria. CONCLUSION Antimicrobial- and diagnosis code-based screening may be a useful method for enhancing and streamlining SSI surveillance for a variety of surgical procedures, including those procedures targeted by the Centers for Medicare and Medicaid Services.

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.

Colonization with Antibiotic-Susceptible Strains Protects against Methicillin-Resistant Staphylococcus aureus but not Vancomycin-Resistant Enterococci Acquisition: A Nested Case-Control Study

IntroductionHarboring sensitive strains may prevent acquisition of resistant pathogens by competing for colonization of ecological niches. Competition may be relevant to decolonization strategies that eliminate sensitive strains and may predispose to acquiring resistant strains in high-endemic settings. We evaluated the impact of colonization with methicillin-sensitive Staphylococcus aureus (MSSA) and vancomycin-sensitive enterococci (VSE) on acquisition of methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), respectively, when controlling for other risk factors.MethodsWe conducted a nested case-control study of patients admitted to eight ICUs performing admission and weekly bilateral nares and rectal screening for MRSA and VRE, respectively. Analyses were identical for both pathogens. For MRSA, patients were identified who had a negative nares screen and no prior history of MRSA. We evaluated predictors of MRSA acquisition, defined as a subsequent MRSA-positive clinical or screening culture, compared to those with a subsequent MRSA-negative nares screen within the same hospitalization. Medical records were reviewed for the presence of MSSA on the initial MRSA-negative nares screen, demographic and comorbidity information, medical devices, procedures, antibiotic utilization, and daily exposure to MRSA-positive patients in the same ward. Generalized linear mixed models were used to assess predictors of acquisition.ResultsIn multivariate models, MSSA carriage protected against subsequent MRSA acquisition (OR = 0.52, CI: 0.29, 0.95), even when controlling for other risk factors. MRSA predictors included intubation (OR = 4.65, CI: 1.77, 12.26), fluoroquinolone exposure (OR = 1.91, CI: 1.20, 3.04), and increased time from ICU admission to initial negative swab (OR = 15.59, CI: 8.40, 28.94). In contrast, VSE carriage did not protect against VRE acquisition (OR = 1.37, CI: 0.54, 3.48), whereas hemodialysis (OR = 2.60, CI: 1.19, 5.70), low albumin (OR = 2.07, CI: 1.12, 3.83), fluoroquinolones (OR = 1.90, CI: 1.14, 3.17), third-generation cephalosporins (OR = 1.89, CI: 1.15, 3.10), and increased time from ICU admission to initial negative swab (OR = 15.13, CI: 7.86, 29.14) were predictive.ConclusionsMSSA carriage reduced the odds of MRSA acquisition by 50% in ICUs. In contrast, VSE colonization was not protective against VRE acquisition. Studies are needed to evaluate whether decolonization of MSSA ICU carriers increases the risk of acquiring MRSA when discharging patients to high-endemic MRSA healthcare settings. This may be particularly important for populations in whom MRSA infection may be more frequent and severe than MSSA infections, such as ICU patients.

Chlorhexidine and Mupirocin Susceptibility of Methicillin-Resistant Staphylococcus aureus Isolates in the REDUCE-MRSA Trial

ABSTRACT Whether targeted or universal decolonization strategies for the control of methicillin-resistant Staphylococcus aureus (MRSA) select for resistance to decolonizing agents is unresolved. The REDUCE-MRSA trial (ClinicalTrials registration no. NCT00980980) provided an opportunity to investigate this question. REDUCE-MRSA was a 3-arm, cluster-randomized trial of either screening and isolation without decolonization, targeted decolonization with chlorhexidine and mupirocin, or universal decolonization without screening to prevent MRSA infection in intensive-care unit (ICU) patients. Isolates from the baseline and intervention periods were collected and tested for susceptibility to chlorhexidine gluconate (CHG) by microtiter dilution; mupirocin susceptibility was tested by Etest. The presence of the qacA or qacB gene was determined by PCR and DNA sequence analysis. A total of 3,173 isolates were analyzed; 2 were nonsusceptible to CHG (MICs, 8 μg/ml), and 5/814 (0.6%) carried qacA or qacB. At baseline, 7.1% of MRSA isolates expressed low-level mupirocin resistance, and 7.5% expressed high-level mupirocin resistance. In a mixed-effects generalized logistic regression model, the odds of mupirocin resistance among clinical MRSA isolates or MRSA isolates acquired in an ICU in intervention versus baseline periods did not differ across arms, although estimates were imprecise due to small numbers. Reduced susceptibility to chlorhexidine and carriage of qacA or qacB were rare among MRSA isolates in the REDUCE-MRSA trial. The odds of mupirocin resistance were no different in the intervention versus baseline periods across arms, but the confidence limits were broad, and the results should be interpreted with caution.

Beyond 30 days: Does limiting the duration of surgical site infection follow-up limit detection?

We evaluated the fraction of deep and organ/space SSIs detected beyond 30 days following CABG, orthopedic procedures, and mastectomy with implant surgical procedures to inform whether a longer SSI surveillance time period identifies sufficient additional SSI cases to warrant additional surveillance resources. SSIs were identified as part of retrospective cohort studies at five hospitals following total hip replacements (THRs) and total knee replacements (TKRs) performed from January 1, 2007 – December 31, 2007.4 SSIs with onset of infection within 365 days of surgery were identified by: a) routine surveillance by hospital infection prevention programs, which was not standardized and commonly involved a combination of review of microbiology records and evaluation of readmissions or reoperations that came to attention, and b) cases flagged by a previously-validated algorithm involving antibiotic data, administrative diagnostic codes, and readmission criteria.5 Previously-identified post-CABG SSIs were identified from a 2005 retrospective cohort study of Medicare beneficiaries undergoing CABG in US hospitals ranked in the top and bottom deciles based upon case mix–adjusted probabilities of an SSI-related claim code within 60 days of surgery. The Romano score was used for case mix adjustment, and was demonstrated as a significant predictor of SSI. 6 Randomly selected medical records were reviewed for SSI. Lastly, we evaluated previously identified SSI cases following mastectomy procedures involving implantation of prosthetic material from an academic medical center (August 2005–December 2007). Data were collected from the surgical admission, readmissions and clinic visits within one year of surgery. 7 All SSIs were limited to those involving deep incisional (DI) or organ/space (OS) infections. Time from surgery to SSI onset was calculated for all SSIs and grouped into ≤30 days and 31–60 days for CABG, while TKR, THR and mastectomy procedures included additional groupings of 61–90 days, and 91–365 days. We identified 27 SSIs following 1,666 TKRs, 21 SSIs following 1,691 THRs, 477 SSI following 23,376 CABGs, and 54 SSIs following 327 mastectomies with implants (Figure 1). Based upon these identified SSIs, TKR required 60 days to identify the majority of cases.8 By 90 days post-procedure, 100% of known DI/OS SSIs were identified for THR, 70% of DI/OS SSIs for TKR, and 87% of DI/OS SSIs for mastectomy with implants. Limiting post-operative SSI surveillance to 30-days would lead to under-reporting of approximately one quarter to two thirds of DI/OS SSIs across the four procedures surveyed. Confining post-operative SSI surveillance to 60 days, as was done for all CABG procedures, results in detection of the vast majority of DI/OS SSIs following THR and mastectomy-plus-implant procedures, but only half of DI/OS SSIs following TKR. In contrast, a 90-day window detected most DI/OS SSIs across these three procedures. A limitation of all SSI estimates across THR, TKR and mastectomy-plus-implant procedures was that follow-up was confined to the hospital where the index procedure was performed. Therefore, results represent minimum estimates of infection since post-discharge outpatient events and SSIs identified at other hospitals were not captured. In contrast, the use of insurer claims to identify CABG SSIs regardless of the location of medical care would allow for more confidence that all medically attended DI/OS infections were captured.6 Figure 1 Distribution of time to onset of Deep-incisional (DI) and Organ space (OS) surgical site infections (SSIs) following total knee replacement (TKR), total hip replacement (THR), mastectomy with implant reconstruction, and coronary artery bypass grafting ... Impending CMS SSI surveillance measures for mandatory reporting should consider including DI/OS SSI surveillance periods for TKR, THR, CABG and mastectomy-plus-implant procedures beyond 30 days. Nevertheless, additional research is needed to assess whether resources to extend surveillance out to 365 days post-procedures is prudent given limited resources, the fact that most DI/OS SSIs are captured within 90 days, and the uncertainty whether SSIs occurring that long after surgery are in fact due to preventable issues at the time of the operation. Regardless of which duration of post-discharge surveillance is selected, assurance that hospitals are conducting post-discharge surveillance using standardized methods is necessary for inter-hospital comparison. Training and validation to ensure similarly comprehensive SSI capture across hospitals is critical for valid public reporting used to determine Medicare payment. In addition, comparison and improvement of existing case mix adjustors should be performed to properly account for different patient population risks for SSI. Early successful explorations into the use of large networks of claims-based databases appear promising in this regard since both case mix adjustment and claims-based algorithms to trigger chart review have been shown to be superior to routine surveillance performed by hospital infection prevention programs for SSI detection and can be used to standardize post-discharge SSI surveillance. 6, 9, 10

Effect of body surface decolonisation on bacteriuria and candiduria in intensive care units: an analysis of a cluster-randomised trial

BACKGROUND Urinary tract infections (UTIs) are common health-care-associated infections. Bacteriuria commonly precedes UTI and is often treated with antibiotics, particularly in hospital intensive care units (ICUs). In 2013, a cluster-randomised trial (REDUCE MRSA Trial [Randomized Evaluation of Decolonization vs Universal Clearance to Eradicate MRSA]) showed that body surface decolonisation reduced all-pathogen bloodstream infections. We aim to further assess the effect of decolonisation on bacteriuria and candiduria in patients admitted to ICUs. METHODS We did a secondary analysis of a three-group, cluster-randomised trial of 43 hospitals (clusters) with patients in 74 adult ICUs. The three groups included were either meticillin-resistant Staphylococcus aureus (MRSA) screening and isolation, targeted decolonisation (screening, isolation, and decolonisation of MRSA carriers) with chlorhexidine and mupirocin, and universal decolonisation (no screening, all patients decolonised) with chlorhexidine and mupirocin. Protocol included chlorhexidine cleansing of the perineum and proximal 6 inches (15·24 cm) of urinary catheters. ICUs within the same hospital were assigned the same strategy. Outcomes included high-level bacteriuria (≥50 000 colony forming units [CFU]/mL) with any uropathogen, high-level candiduria (≥50 000 CFU/mL), and any bacteriuria with uropathogens. Sex-specific analyses were specified a priori. Proportional hazards models assessed differences in outcome reductions across groups, comparing an 18-month intervention period to a 12-month baseline period. FINDINGS 122 646 patients (48 390 baseline, 74 256 intervention) were enrolled. Intervention versus baseline hazard ratios (HRs) for high-level bacteriuria were 1·02 (95% CI 0·88-1·18) for screening or isolation, 0·88 (0·76-1·02) for targeted decolonisation, and 0·87 (0·77-1·00) for universal decolonisation (no difference between groups, p=0·26), with no sex-specific reductions (HRs for men: 1·09 [95% CI 0·85-1·40] for screening or isolation, 1·01 [0·79-1·29] for targeted decolonisation, and 0·78 [0·63-0·98] for universal decolonisation, p=0·12; HRs for women: 0·97 [0·80-1·17] for screening and isolation, 0·83 [0·70-1·00] for targeted decolonisation, and 0·93 [0·79-1·09] for universal decolonisation, p=0·49). HRs for high-level candiduria were 1·14 (0·95-1·37) for screening and isolation, 0·99 (0·83-1·18) for targeted decolonisation, and 0·83 (0·70-0·99) for universal decolonisation (p=0·05). Differences between sexes were due to reductions in men in the universal decolonisation group (HRs: 1·21 [95% CI 0·88-1·68] for screening or isolation, 1·01 [0·73-1·39] for targeted decolonisation, and 0·63 [0·45-0·89] for universal decolonisation, p=0·02). Bacteriuria with any CFU/mL was also reduced in men in the universal decolonisation group (HRs 1·01 [0·81-1·25] for screening or isolation, 1·04 [0·83-1·30] for targeted decolonisation, and 0·74 [0·61-0·90] for universal decolonisation, p=0·04). INTERPRETATION Universal decolonisation of patients in the ICU with once a day chlorhexidine baths and short-course nasal mupirocin could be a potential preventive strategy in male patients because it significantly decreases candiduria and any bacteriuria, but not for women. FUNDING HAI Program from AHRQ, US Department of Health and Human Services as part of the Developing Evidence to Inform Decisions about Effectiveness (DEcIDE) program, CDC Prevention Epicenters Program.

Does Chlorhexidine Bathing in Adult Intensive Care Units Reduce Blood Culture Contamination? A Pragmatic Cluster-Randomized Trial

OBJECTIVE To determine rates of blood culture contamination comparing 3 strategies to prevent intensive care unit (ICU) infections: screening and isolation, targeted decolonization, and universal decolonization. DESIGN Pragmatic cluster-randomized trial. SETTING Forty-three hospitals with 74 ICUs; 42 of 43 were community hospitals. PATIENTS Patients admitted to adult ICUs from July 1, 2009, to September 30, 2011. METHODS After a 6-month baseline period, hospitals were randomly assigned to 1 of 3 strategies, with all participating adult ICUs in a given hospital assigned to the same strategy. Arm 1 implemented methicillin-resistant Staphylococcus aureus (MRSA) nares screening and isolation, arm 2 targeted decolonization (screening, isolation, and decolonization of MRSA carriers), and arm 3 conducted no screening but universal decolonization of all patients with mupirocin and chlorhexidine (CHG) bathing. Blood culture contamination rates in the intervention period were compared to the baseline period across all 3 arms. RESULTS During the 6-month baseline period, 7,926 blood cultures were collected from 3,399 unique patients: 1,099 sets in arm 1, 928 in arm 2, and 1,372 in arm 3. During the 18-month intervention period, 22,761 blood cultures were collected from 9,878 unique patients: 3,055 sets in arm 1, 3,213 in arm 2, and 3,610 in arm 3. Among all individual draws, for arms 1, 2, and 3, the contamination rates were 4.1%, 3.9%, and 3.8% for the baseline period and 3.3%, 3.2%, and 2.4% for the intervention period, respectively. When we evaluated sets of blood cultures rather than individual draws, the contamination rate in arm 1 (screening and isolation) was 9.8% (N = 108 sets) in the baseline period and 7.5% (N = 228) in the intervention period. For arm 2 (targeted decolonization), the baseline rate was 8.4% (N = 78) compared to 7.5% (N = 241) in the intervention period. Arm 3 (universal decolonization) had the greatest decrease in contamination rate, with a decrease from 8.7% (N = 119) contaminated blood cultures during the baseline period to 5.1% (N = 184) during the intervention period. Logistic regression models demonstrated a significant difference across the arms when comparing the reduction in contamination between baseline and intervention periods in both unadjusted (P = .02) and adjusted (P = .02) analyses. Arm 3 resulted in the greatest reduction in blood culture contamination rates, with an unadjusted odds ratio (OR) of 0.56 (95% confidence interval [CI], 0.044-0.71) and an adjusted OR of 0.55 (95% CI, 0.43-0.71). CONCLUSION In this large cluster-randomized trial, we demonstrated that universal decolonization with CHG bathing resulted in a significant reduction in blood culture contamination.

Infection prevention practices in adult intensive care units in a large community hospital system after implementing strategies to reduce health care-associated, methicillin-resistant Staphylococcus aureus infections.

BACKGROUND A range of strategies and approaches have been developed for preventing health care-associated infections. Understanding the variation in practices among facilities is necessary to improve compliance with existing programs and aid the implementation of new interventions. METHODS In 2009, HCA Inc administered an electronic survey to measure compliance with evidence-based infection prevention practices as well as identify variation in products or methods, such as use of special approach technology for central vascular catheters and ventilator care. Responding adult intensive care units (ICUs) were those considering participation in a clinical trial to reduce health care-associated infections. RESULTS Responses from 99 ICUs in 55 hospitals indicated that many evidenced-based practices were used consistently, including methicillin-resistant Staphylococcus aureus (MRSA) screening and use of contact precautions for MRSA-positive patients. Other practices exhibited wide variability including discontinuation of precautions and use of antimicrobial technology or chlorhexidine patches for central vascular catheters. MRSA decolonization was not a predominant practice in ICUs. CONCLUSION In this large, community-based health care system, there was substantial variation in the products and methods to reduce health care-associated infections. Despite system-wide emphasis on basic practices as a precursor to adding special approach technologies, this survey showed that these technologies were commonplace, including in facilities where improvement in basic practices was needed.