Serum Piperacillin/Tazobactam Pharmacokinetics in a Morbidly Obese Individual

Objective:

To report pharmacokinetic alterations and optimal dosing of piperacillin/tazobactam in an obese patient.

Case Summary:

A 39-year-old morbidly obese (weight 167 kg, body mass index 50 kg/m2) man was treated with piperacillin/tazobactam 3.375 g every 4 hours for recurrent cellulitis. The wound culture grew Groups A and B Streptococcus and rare Pseudomonas aeruginosa. Blood samples were obtained at steady-state from a peripheral venous catheter at 0, 0.5, 1, 2, 3, and 4 hours after the start of the infusion. Population pharmacokinetics were generated from a previously published data set. The serum concentrations of piperacillin/tazobactam obtained in the patient were compared with the 95% confidence interval from the representative population. Pharmacokinetic parameters such as maximal serum concentration, minimal serum concentration, average steady-state concentration, half-life, elimination rate constant, volume of distribution (Vd), clearance, area under the curve at steady-state, and percent of time greater than the minimum inhibitory concentration (%t>MIC) were calculated and qualitatively compared between the sample and the population.

Discussion:

Substantial differences were noted in both the absolute values at the times of sample collection and the overall concentration-versus-time profile of both compounds. The morbidly obese individual compared with the population demonstrated a reduced average serum steady-state concentration: 39.8 mg/L versus 123.6 mg/L, an increased Vd: 54.3 L versus 12.7 L, and an increased half-life: 1.4 hours versus 0.6 hours, respectively. The %t>MIC of piperacillin for the patient, assuming MICs of 2, 4, 8, 16, 32, 64, and 128 mg/L, was 100%. 100%, 90.9%, 55.4%. 19.9%, 0%, and 0%, respectively.

Conclusions:

Pathogens with elevated MICs may require altered dosing schemes with piperacillin/tazobactam. Future studies are warranted to assess increased dosages, more frequent dosing intervals, or continuous infusion dosing schemes for obese individuals with serious infections.

Respiratory syncytial virus outbreak on an adult stem cell transplant unit

BACKGROUND

An increase in respiratory syncytial virus type B (RSV-B) infections was detected on an adult hematology/oncology and stem cell transplant unit during March 2015. This prompted an outbreak investigation.

METHODS

Nosocomial cases were defined as RSV-B-positive patients who developed respiratory virus symptoms ≥ 7 days after admission to the unit or were readmitted with symptoms ≤ 7 days since last discharge from the unit. Strict outbreak control measures were implemented to stop the outbreak.

RESULTS

During the outbreak, 19 cases of RSV-B were detected, 14 among patients and 5 among health care workers (HCWs). Additionally, 2 HCWs tested positive for respiratory syncytial virus type A and 1 tested positive for influenza B among the 27 symptomatic HCWs evaluated. No specific antiviral therapy was given and all cases recovered without progression to lower respiratory tract infection. After no new cases were identified for 2 weeks, the outbreak was declared over.

CONCLUSIONS

High vigilance for respiratory viruses on high-risk inpatient units is required for detection and prevention of potential outbreaks. Multiple respiratory viruses with outbreak potential were identified among HCWs. HCWs with respiratory virus symptoms should not provide direct patient care. Absence of lower respiratory tract infection suggests lower virulence of RSV-B, compared with respiratory syncytial virus type A, among immunocompromised adults.

Risk Factors and Outcomes Associated With Non–Enterococcus faecalis, Non–Enterococcus faeciumEnterococcal Bacteremia

Objectives.

To compare risk factors, clinical features, and outcomes in patients withEnterococcus avium,Enterococcus casseliflavus,Enterococcus durans,Enterococcus gallinarum, andEnterococcus mundtiibacteremia (cases) with those in patients withEnterococcus faecalisbacteremia (controls).

Design.

A retrospective case-control study.

Setting.

A 725-bed, university-affiliated, academic medical center.

Patients.

The clinical microbiology database at Northwestern Memorial Hospital from January 1994 to May 2003 was searched to identify cases; each case was matched to one control on the basis of date of admission.

Results.

Thirty-three cases were identified and matched with 33 controls. The mean duration of hospital stay was longer (29.7 vs 17.2 days;P= .03) and the mean time to acquisition of bacteremia was greater (16.5 vs 6.3 days;P= .003) for cases than controls. Cases were more likely to have underlying hematologic malignancies (P< .001), to have been treated with corticosteroids (P= .02), and to be neutropenic (P= .003). Controls were more likely to have an indwelling bladder catheter (P= .01), and cases were more likely to have the gastrointestinal tract as a source of infection (P= .007) and to have concurrent cholangitis (P= .002). There were no differences in severity of illness or in mortality rates.

Conclusions.

Compared with patients withE. faecalisbacteremia, patients with non-E. faecalis, non-Enterococcus faeciumenterococcal bacteremia were more likely to have a hematologic malignancy, prior treatment with corticosteroids, neutropenia, and cholangitis; longer duration of hospital stay was also identified as a clinical feature. However, non-E. faecalis, non-E. faeciumspecies are not associated with any differences in mortality.

Management of Outbreaks of Methicillin-ResistantStaphylococcus aureusInfection in the Neonatal Intensive Care Unit: A Consensus Statement

Objective.

In 2002, the Chicago Department of Public Health (CDPH; Chicago, Illinois) convened the Chicago-Area Neonatal MRSA Working Group (CANMWG) to discuss and compare approaches aimed at control of methicillin-resistantStaphylococcus aureus(MRSA) in neonatal intensive care units (NICUs). To better understand these issues on a regional level, the CDPH and the Evanston Department of Health and Human Services (EDHHS; Evanston, Illinois) began an investigation.

Design.

Survey to collect demographic, clinical, microbiologic, and epidemiologic data on individual cases and clusters of MRSA infection; an additional survey collected data on infection control practices.

Setting.

Level III NICUs at Chicago-area hospitals.

Participants.

Neonates and healthcare workers associated with the level III NICUs.

Methods.

From June 2001 through September 2002, the participating hospitals reported all clusters of MRSA infection in their respective level III NICUs to the CDPH and the EDHHS.

Results.

Thirteen clusters of MRSA infection were detected in level III NICUs, and 149 MRSA-positive infants were reported. Infection control surveys showed that hospitals took different approaches for controlling MRSA colonization and infection in NICUs.

Conclusion.

The CANMWG developed recommendations for the prevention and control of MRSA colonization and infection in the NICU and agreed that recommendations should expand to include future data generated by further studies. Continuing partnerships between hospital infection control personnel and public health professionals will be crucial in honing appropriate guidelines for effective approaches to the management and control of MRSA colonization and infection in NICUs.

Preventing Catheter-Associated Bloodstream Infections: A Survey of Policies for Insertion and Care of Central Venous Catheters From Hospitals in the Prevention Epicenter Program

Objective.

To determine the extent to which evidence-based practices for the prevention of central venous catheter (CVC)-associated bloodstream infections are incorporated into the policies and practices of academic intensive care units (ICUs) in the United States and to determine variations in the policies on CVC insertion, use, and care.

Design.

A 9-page written survey of practices and policies for nontunneled CVC insertion and care.

Setting.

ICUs in 10 academic tertiary-care hospitals.

Participants.

ICU medical directors and nurse managers.

Results.

Twenty-five ICUs were surveyed (1-6 ICUs per hospital). In 80% of the units, 5 separate groups of clinicians inserted 24%-50% of all nontunneled CVCs. In 56% of the units, placement of more than two-thirds of nontunneled CVCs was performed in a single location in the hospital. Twenty units (80%) had written policies for CVC insertion. Twenty-eight percent of units had a policy requiring maximal sterile-barrier precautions when CVCs were placed, and 52% of the units had formal educational programs with regard to CVC insertion. Eighty percent of the units had a policy requiring staff to perform hand hygiene before inserting CVCs, but only 36% and 60% of the units required hand hygiene before accessing a CVC and treating the exit site, respectively.

Conclusion.

ICU policy regarding the insertion and care of CVCs varies considerably from hospital to hospital. ICUs may be able to improve patient outcome if evidence-based guidelines for CVC insertion and care are implemented.

Abstract 161: Heart Failure Care Transitions: A Queuing Theory Approach to Match Variable Hospital Discharge Rate With Outpatient Clinic Capacity

Background: Heart failure (HF) readmissions remain a major driver of cost and health care utilization. Timely follow-up of patients post-discharge represents an evidence-based intervention proven to reduce readmission rates. A previously unexplored characteristic of hospital discharges is variability in discharge caseload. This variability thwarts the timeliness of follow-up, negates the benefit of transition care planning and may lead to a higher risk of HF readmissions. Queuing theory is the mathematical study of waiting times. We opted to use queuing theory to determine if caseload can be determined more precisely in a manner that sufficiently accommodates HF discharge variability.

Objective: To analyze the impact of hospital discharge rate variability on outpatient clinic capacity needs using HF hospitalization discharge data and operations management approaches.

Methods: Higher risk hospitalizations requiring active transitional care heart failure management were detected using an enterprise data warehouse-supported process over the study period. Queuing theory approaches were used to model the impact of HF discharge clinic capacity on wait time to an appointment. Discharge clinic was modeled as a single 7-day follow-up appointment, with an acceptable scheduling window of 5 to 9 days post-discharge.

Results: During the study period of 100 days, 566 HF discharges were made, for a median of 5.66 discharges daily, or 39.6 discharges weekly. The distribution of daily discharges was skewed rightward (mode = 3, range = 0 to 18, standard deviation = 3.3, coefficient of variation = 0.58). Current clinic design: Providing one discharge slot for every hospital discharge (100% utilization) leads to an average wait of 18.3 days prior to an appointment, with only 31.9% of appointments scheduled within 7 days, and 38.9% of appointments scheduled within 9 days. Clinic re-design (queuing theory): Providing five extra discharge appointment slots per week (88% utilization or 13.6% excess capacity) reduces the expected waiting period to 1.1 days, with 99.8% of patients seen within 7 days, and virtually all patients seen within 9 days of discharge.

Conclusions: Deployment of queuing theory allows for a more precise quantification of needed clinical capacity to accomplish appropriate HF follow-up with a reasonable degree of certainty. Our simplified model demonstrates that variability in hospital discharge rates leads to excessive clinic wait times in the absence of a modest capacity buffer and consequently exposes patients to a higher risk of HF readmission. We show using single center HF discharge data that a 10-15% increase in capacity is needed to ensure an adequate follow-up service level. Ongoing process of care work will demonstrate if optimization of clinic load yields a significant reduction in HF readmissions.

Contamination of Examination Gloves in patient Rooms and Implications for Transmission of Antimicrobial-Resistant Microorganisms

An assessment of bacterial contamination on examination gloves indicated that contaminated gloves may be a mechanism of indirect bacterial transmission from the hands of healthcare workers to patients. This mechanism is indicated by the recovery of identical Acinetobacter baumannii isolates from gloves and from the clinical cultures of a patient with invasive infection.

Legislative Mandates for Use of Active Surveillance Cultures to Screen for Methicillin-ResistantStaphylococcus aureusand Vancomycin-Resistant Enterococci: Position Statement From the Joint SHEA and APIC Task Force

Legislation aimed at controlling antimicrobial-resistant pathogens through the use of active surveillance cultures to screen hospitalized patients has been introduced in at least 2 US states. In response to the proposed legislation, the Society for Healthcare Epidemiology of America (SHEA) and the Association of Professionals in Infection Control and Epidemiology (APIC) have developed this joint position statement. Both organizations are dedicated to combating healthcare-associated infections with a wide array of methods, including the use of active surveillance cultures in appropriate circumstances. This position statement reviews the proposed legislation and the rationale for use of active surveillance cultures, examines the scientific evidence supporting the use of this strategy, and discusses a number of unresolved issues surrounding legislation mandating use of active surveillance cultures. The following 5 consensus points are offered. (1) Although reducing the burden of antimicrobial-resistant pathogens, including methicillin-resistantStaphylococcus aureus(MRSA) and vancomycin-resistant enterococci (VRE), is of preeminent importance, APIC and SHEA do not support legislation to mandate use of active surveillance cultures to screen for MRSA, VRE, or other antimicrobial-resistant pathogens. (2) SHEA and APIC support the continued development, validation, and application of efficacious and cost-effective strategies for the prevention of infections caused by MRSA, VRE, and other antimicrobial-resistant and antimicrobial-susceptible pathogens. (3) APIC and SHEA welcome efforts by healthcare consumers, together with private, local, state, and federal policy makers, to focus attention on and formulate solutions for the growing problem of antimicrobial resistance and healthcare-associated infections. (4) SHEA and APIC support ongoing additional research to determine and optimize the appropriateness, utility, feasibility, and cost-effectiveness of using active surveillance cultures to screen both lower-risk and high-risk populations. (5) APIC and SHEA support stronger collaboration between state and local public health authorities and institutional infection prevention and control experts.

Evaluation of Postprescription Review and Feedback as a Method of Promoting Rational Antimicrobial Use: A Multicenter Intervention

Objective.

To evaluate the impact of postprescription review of broad-spectrum antimicrobial (study-ABX) agents on rates of antimicrobial use.

Design.

Quasi-experimental before-after study.

Setting.

Five academic medical centers.

Patients.

Adults receiving at least 48 hours of study-ABX.

Methods.

The baseline, intervention, and follow-up periods were 6 months each in 2 units at each of 5 sites. Adults receiving at least 48 hours of study-ABX entered the cohort as case-patients. During the intervention, infectious-diseases physicians reviewed the cases after 48 hours of study-ABX. The provider was contacted with alternative recommendations if antimicrobial use was considered to be unjustified on the basis of predetermined criteria. Acceptance rates were assessed 48 hours later. The primary outcome measure was days of study-ABX per 1,000 study-patient-days in the baseline and intervention periods.

Results.

There were 1,265 patients in the baseline period and 1,163 patients in the intervention period. Study-ABX use decreased significantly during the intervention period at 2 sites: from 574.4 to 533.8 study-ABX days/1,000 patient-days (incidence rate ratio [IRR], 0.93; 95% confidence interval [CI], 0.88-0.97; P = .002) at hospital В and from 615.6 to 514.4 study-ABX days/1,000 patient-days (IRR, 0.83; 95% CI, 0.79-0.88; P < .001) at hospital D. Both had established antimicrobial stewardship programs (ASP). Study-ABX use increased at 2 sites and stayed the same at 1 site. At all institutions combined, 390 of 1,429 (27.3%) study-ABX courses were assessed as unjustified; recommendations to modify or stop therapy were accepted for 260 (66.7%) of these courses.

Conclusions.

Postprescription review of study-ABX decreased antimicrobial utilization in some of the study hospitals and may be more effective when performed as part of an established ASP.

Indirect protection of adults from rotavirus by pediatric rotavirus vaccination

BACKGROUND

Pediatric vaccination has resulted in declines in disease in unvaccinated individuals through decreasing pathogen circulation in the community. About 2 years after implementation of pediatric rotavirus vaccination in the United States, dramatic declines in rotavirus disease were observed in both vaccinated and unvaccinated children. Whether this protection extends to adults is unknown.

METHODS

The prevalence of rotavirus, as determined by Rotaclone enzyme immunoassay, in adults who had stools submitted for bacterial stool culture (BSC) between February to May to Northwestern Memorial Hospital, Chicago, was compared between the prepediatric impact era (2006-2007) and the pediatric impact era (2008-2010). Isolates were genotyped and clinical characteristics of those with rotavirus were compared.

RESULTS

Of the 5788 BSC sent, 4725 met inclusion criteria and 3530 of these (74.7%) were saved for rotavirus testing. The prevalence of rotavirus among adults who had stool sent for BSC declined from 4.35% in 2006-2007 to 2.24% in 2008-2010 (a relative decline of 48.4%; P = .0007). The decline in the prevalence of rotavirus was of similar significant magnitude in both outpatients and inpatients. Marked year-to-year variability was observed in circulating rotavirus genotypes, with strain G2P[4] accounting for 24%; G1P[8], 22%; G3P[8], 11%; and G12P[6], 10% overall. About 30% of adults from whom rotavirus was isolated were immunocompromised and this remained constant.

CONCLUSIONS

Pediatric rotavirus vaccination correlated with a relative decline of almost 50% in rotavirus identified from adult BSC during the peak rotavirus season, suggesting that pediatric rotavirus vaccination protects adults from rotavirus.

The impact of infection control upon hospital-acquired influenza and respiratory syncytial virus

BACKGROUND

Respiratory syncytial virus (RSV) and influenza are important pediatric community-acquired (CA) and hospital-acquired (HA) pathogens. The occurrence of pandemic (H1N1) 2009 influenza resulted in additional efforts to intensify infection control (IC) strategies. We detail the impact of IC strategies between 2003 and 2010 on influenza and RSV.

METHODS

We assessed the rates of CA infections per 100 admissions and HA infections per 1000 patient-days for both RSV and influenza at Children's Memorial Hospital during the winter seasons (September through May) 2003-2010. The season of 2009, however, was extended through June due to ongoing admissions as a result of pandemic (H1N1) 2009 influenza. IC strategies implemented in response to pandemic (H1N1) 2009 influenza are described. The transmission ratio (HA cases/CA cases) was determined and correlated with IC efforts.

RESULTS

Substantial season- to-season variability exists for CA RSV and CA influenza rates. The rates of HA RSV and HA influenza and the transmission ratios for these viruses remained unchanged in 2009-10 in comparison to the prior year (at 0.02 and 0.01, respectively) despite implementation of multiple IC strategies. In contrast, since 2005 an inverse association was noted between hand hygiene compliance and the transmission ratio of both RSV and influenza, with Spearman correlation coefficients of -0.84 (p = 0.051) and -0.89 (p = 0.008), respectively.

CONCLUSIONS

We observed that improvements in hand hygiene compliance correlated with less transmission of RSV and influenza in the hospital. The important role of hand hygiene in preventing transmission of RSV and influenza to hospitalized children should be emphasized.

Rotavirus in adults requiring hospitalization

OBJECTIVES

To determine the prevalence and epidemiological characteristics of rotavirus among adults admitted to the hospital with diarrhea that have bacterial stool cultures sent.

METHODS

The prevalence of rotavirus was determined by Rotaclone EIA in samples submitted for bacterial stool culture from adults requiring hospitalization at Northwestern Memorial Hospital, Chicago from December 01, 2005-November 30, 2006.

RESULTS

Rotavirus was detected in 2.9% of eligible bacterial stool cultures. A bacterial pathogen (e.g., Salmonella, Shigella, Campylobacter) was identified in 3.3%. Bacterial stool pathogens were more common from June-October while rotavirus was 2.4 times more common than all bacterial pathogens from February-May. Adults in whom rotavirus was detected were older (p < 0.05) and more often immunosuppressed (p < 0.02), particularly with HIV (p < 0.04) compared to individuals from whom bacteria were isolated. The duration of hospitalization and the number of invasive procedures performed in those with rotavirus and bacterial diarrhea were comparable.

CONCLUSIONS

In the era immediately prior to widespread rotavirus vaccination of children, rotavirus was as commonly detected from adults admitted to the hospital with diarrhea as are the bacterial gastroenteritis pathogens. Rotavirus is particularly prevalent from February-May (as in children) and in immunosuppressed or older adults.

Native valve endocarditis due to a novel strain of Legionella

Legionellae are Gram-negative bacteria which are capable of causing disease, most commonly in the form of pneumonia. We describe a case of native valve endocarditis caused by a Legionella strain which by genotypic (16S rRNA and mip gene sequencing) and phenotypic analyses is unlike previously described strains of Legionella.

Impact of rotavirus vaccination on hospital-acquired rotavirus gastroenteritis in children

OBJECTIVE

Data show that after the implementation of routine rotavirus vaccination for infants in the United States, community-acquired (CA) rotavirus cases declined substantially in the 2007-2008 season. The impact of community-based rotavirus vaccination on the substantial burden of hospital-acquired (HA) rotavirus has not been documented.

PATIENTS AND METHODS

We assessed CA and HA rotavirus, respiratory syncytial virus, and influenza infections at Children's Memorial Hospital for 5 winter seasons (defined as occurring from September through May) from 2003 to 2008. We also report rotavirus data from the 2008-2009 season.

RESULTS

A similar dramatic decline (>60% compared with the median of previous seasons) occurred in the rates of cases of both CA (P < .0001) rotavirus hospitalizations and HA (P < .01) rotavirus infections in the 2007-2008 season compared with previous seasons, whereas the rates of CA and HA influenza and respiratory syncytial virus, respectively, remained stable. Improvements in hand-hygiene compliance did not correlate with a reduction in the transmission rate of rotavirus in the hospital. Both CA and HA rotavirus rates remained much lower in the 2008-2009 than in the 2003-2007 seasons.

CONCLUSIONS

Community-based rotavirus vaccination is associated with a substantial reduction in the number of children who are admitted with rotavirus. These data also indicate that routine community-based rotavirus infant vaccination protects hospitalized children from acquiring rotavirus. Vaccination efforts should be encouraged as a strategy to affect the substantial burden of HA rotavirus.

Results of the Medications at Transitions and Clinical Handoffs (MATCH) study: an analysis of medication reconciliation errors and risk factors at hospital admission

BACKGROUND

This study was designed to determine risk factors and potential harm associated with medication errors at hospital admission.

METHODS

Study pharmacist and hospital-physician medication histories were compared with medication orders to identify unexplained history and order discrepancies in 651 adult medicine service inpatients with 5,701 prescription medications. Discrepancies resulting in order changes were considered errors. Logistic regression was used to analyze the association of patient demographic and clinical characteristics including patients' number of pre-admission prescription medications, pharmacies, prescribing physicians and medication changes; and presentation of medication bottles or lists. These factors were tested after controlling for patient demographics, admitting service and severity of illness.

RESULTS

Over one-third of study patients (35.9%) experienced 309 order errors; 85% of patients had errors originate in medication histories, and almost half were omissions. Cardiovascular agents were commonly in error (29.1%). If undetected, 52.4% of order errors were rated as potentially requiring increased monitoring or intervention to preclude harm; 11.7% were rated as potentially harmful. In logistic regression analysis, patient's age > or = 65 [odds ratio (OR), 2.17; 95% confidence interval (CI), 1.09-4.30] and number of prescription medications (OR, 1.21; 95% CI, 1.14-1.29) were significantly associated with errors potentially requiring monitoring or causing harm. Presenting a medication list (OR, 0.35; 95% CI, 0.19-0.63) or bottles (OR, 0.55; 95% CI, 0.27-1.10) at admission was beneficial.

CONCLUSION

Over one-third of the patients in our study had a medication error at admission, and of these patients, 85% had errors originate in their medication histories. Attempts to improve the accuracy of medication histories should focus on older patients with a large number of medications. Primary care physicians and other clinicians should help patients utilize and maintain complete, accurate and understandable medication lists.

Using patient safety morbidity and mortality conferences to promote transparency and a culture of safety

BACKGROUND

Although creating a culture of safety to support clinicians and improve the quality of patient care is a common goal among health care organizations, it can be difficult to envision specific efforts to directly influence organizational culture. To promote transparency and reinforce a nonpunitive attitude throughout the organization, a forum for the open, interdisciplinary discussion of patient safety problems--the Patient Safety Morbidity and Mortality (M&M) Conference--was created at Northwestern Memorial Hospital (Chicago). The intent of the M&M conference was to inform frontline providers about adverse events that occur at the hospital and to engage their input in root cause analysis, thereby encouraging reporting and promoting systems-based thinking among clinicians.

METHODS

Convened under the purview of the organization's quality program, and modeled on the traditional M&M conferences historically used by physicians, the conference is a monthly live meeting at which case studies are presented for retrospective (root cause) analysis by an interdisciplinary audience.

RESULTS

Since its start in 2003, approximately 60 patient safety M&M programs have been presented. Audiences typically represent a mix of physicians, nurses, pharmacists, management, therapists, and administrative and support staff. Staff perceptions of culture, as measured by the Hospital Survey on Patient Safety Culture, showed statistically significant improvements over time.

DISCUSSION

Ensuring the patient safety M&M conference program's sustained success requires an ongoing commitment to identifying events of clinical importance and to pursuing the productive discussion of these events in an open and safe forum. Patient safety M&M conferences are a valued opportunity to engage staff in exploring adverse events and to promote transparency and a nonpunitive culture.

Infection control practices among interventional radiologists: results of an online survey

PURPOSE

To assess current infection control practices of interventional radiologists (IRs) in the context of recommendations by the Centers for Disease Control and Prevention and the Occupational Safety and Health Administration.

MATERIALS AND METHODS

From November 2006 to January 2007, members of the Society of Interventional Radiology (SIR) were invited to participate in an anonymous, online infection control questionnaire.

RESULTS

A total of 3,019 SIR members in the United States were contacted via e-mail, and 1,061 (35%) completed the 57-item survey. Of the respondents, 283 (25%) experienced a needlestick injury within the previous year, most often as a result of operator error (76%). Less than 65% reported compliance with annual tuberculosis skin testing; notably, those who received a yearly reminder were much more likely to receive annual testing than those who did not (odds ratio, 19.0; 95% CI, 12.6-28.7; P < .05). During central venous catheter placement, only 56% wore gowns, 50% wore caps, and 54% used full barrier precautions. Only 19% reported routine hand washing between glove applications. More than 40% noted a change in infection control practices within the previous 5 years, citing new hospital guidelines and recommendations by a professional organization as the reasons for change. Only 44% had infection control training at the onset of their practice.

CONCLUSIONS

IRs demonstrate a wide variety of infection control practices that are not in accordance with current guidelines. IRs were most likely to change infection control practice if required to do so by their own hospitals or a professional organization. SIR can play an important role in the prevention of health care-associated infection by reinforcing current infection control guidelines as they pertain to interventional radiology.

Antibiotic considerations in the treatment of multidrug-resistant (MDR) pathogens: a case-based review

The recent rise in antimicrobial resistance among health-care associated pathogens is a growing public health concern. According to the National Nosocomial Infections Surveillance System, rates of methicillin-resistant Staphylococcus aureus (MRSA) in intensive care units have nearly doubled over the last decade. Of equal importance, gram-negative agents such as Pseudomonas aeruginosa, Acinetobacter baumannii, and extended-spectrum beta lactamase-producing Enterobacteriaceae demonstrate increasing resistance to third-generation cephalosporins, fluoroquinolones, and, in some cases, carbapenems. As a consequence, hospitalists may find themselves utilizing new antibiotics in the treatment of bacterial infections. This case-based review will highlight 8 antibiotics that have emerging clinical indications in treating these multidrug-resistant (MDR) pathogens.

Using theoretical constructs to identify key issues for targeted message design: African American seniors' perceptions about influenza and influenza vaccination

African American seniors (65 and older) are less likely to be vaccinated against influenza than are non-Hispanic White seniors. There is a clear need for targeted messages and interventions to address this disparity. As a first step, 6 focus groups of African American seniors (N = 48) were conducted to identify current perceptions about influenza and influenza vaccination. Emergent thematic categories were organized using the 4 main constructs of the extended parallel process model. Susceptibility varied based on perceptions of individual health status, background knowledge, and age-related risk. Some participants saw influenza as a minor nuisance; others viewed it as threatening and potentially deadly. Participants discussed issues related or antecedent to self-efficacy, including vaccine accessibility and affordability. Regarding response efficacy, some participants had confidence in the vaccine, some questioned its preventive ability or believed that the vaccine caused influenza, and others noted expected side effects. Implications and recommendations for message development are discussed.

Cost-effectiveness analysis of an antimicrobial stewardship team on bloodstream infections: a probabilistic analysis

OBJECTIVES

We sought to determine the cost-effectiveness of Antimicrobial Stewardship Teams (ASTs) on the reduction of morbidity and mortality associated with nosocomial bacteraemia.

METHODS

A decision analytic model compared costs and outcomes of bacteraemic patients receiving standard treatment with or without an AST consult. Patients with a bacteraemic event during their hospital admission were included in the model. Effectiveness was estimated as quality-adjusted life years (QALYs) over the lifetime of patients. Model variables and costs, along with their distributions, were obtained from the literature and expert opinion. Incremental cost-effectiveness ratios (ICERs) were calculated to estimate the cost per QALY gained from the hospital perspective. Uncertainty in ICERs was evaluated with probabilistic sensitivity analyses. The cost-effectiveness of clinical decision support systems was evaluated as a secondary analysis.

RESULTS

Implementing an AST for bacteraemia review cost $39,737 (95% CI $27,272-53, 017) and standard treatment cost $39,563 (95% CI $27,164-52,797). The difference in effectiveness between the two strategies was 0.08 QALYs, and the base case ICER from the probabilistic analysis was $2367 per QALY gained [95% CI dominant (less costly, more effective) to $24,379]. Results from the probabilistic sensitivity analysis demonstrated there was more than a 90% likelihood that an AST would be cost-effective at a level of $10,000 per QALY.

CONCLUSIONS

Maintaining an AST to improve care for bacteraemia is cost-effective from the hospital perspective. The estimate of $2367 per QALY gained for the AST intervention compares favourably with many currently funded healthcare interventions and services.

Use of electronic alerts to enhance hand hygiene compliance and decrease transmission of vancomycin-resistant Enterococcus in a hematology unit

BACKGROUND

Hand hygiene (HH) compliance among health care workers (HCWs) has been historically low and hampered by poor surveillance methods. This study evaluated the use of an electronic device to measure and impact HH compliance.

METHODS

The study is a prospective, interventional study in a 30-bed academic medical center hematology unit. Phase I of the study monitored baseline HH compliance, and phase II monitored HH compliance using automatic alerts. The primary outcome measure was HH compliance, and the secondary end point was nosocomial transmission of vancomycin-resistant Enterococcus (VRE).

RESULTS

Eight thousand two hundred thirty-five HH opportunities were measured during the study, with HH compliance improvement from 36.3% at baseline to 70.1% during phase II. The use of audible alerts improved HH compliance for both the day shift (odds ratio [OR], 3.6) and the night shift (OR, 5.9), as well as across rooms with higher HCW traffic (OR, 1.6) and lower HCW traffic (OR, 3.2).

CONCLUSION

Electronic devices can effectively monitor HH compliance among HCWs and facilitate improved adherence to guidelines. Electronic devices improve HH compliance regardless of time of day or room location. The development of innovative devices to improve HH is required to validate the long-term implications of this methodology.

Budget impact analysis of rapid screening for Staphylococcus aureus colonization among patients undergoing elective surgery in US hospitals

OBJECTIVE

To evaluate the economic impact of performing rapid testing for Staphylococcus aureus colonization before admission for all inpatients who are scheduled to undergo elective surgery and providing subsequent decolonization therapy for those patients found to be colonized with S. aureus.

METHODS

A budget impact model that used probabilistic sensitivity analysis to account for the uncertainties in the input variables was developed. Primary input variables included the marginal effect of S. aureus infection on patient outcomes among patients who underwent elective surgery, patient demographic characteristics, the prevalence of nasal carriage of S. aureus, the sensitivity and specificity of the rapid diagnostic test for S. aureus colonization, the efficacy of decolonization therapy for nasal carriage of S. aureus, and cost data. Data sources for the input variables included the 2003 Nationwide Inpatient Sample data and the published literature.

RESULTS

In 2003, there were an estimated 7,181,484 patients admitted to US hospitals for elective surgery. Our analysis indicated preadmission testing and subsequent decolonization therapy for patients colonized with S. aureus would have produced a mean annual cost savings to US hospitals of $231,538,400 (95% confidence interval [CI], -$300 million to $1.3 billion). The mean annual number of hospital-days that could have been eliminated was estimated at 364,919 days (95% CI, 67,893-926,983 days), and a mean of 935 in-hospital deaths (95% CI, 88-3,691) could have been avoided per year. Sensitivity analysis indicated a 64.5% probability that there would be cost savings to US hospitals as a result of preadmission testing and subsequent decolonization therapy.

CONCLUSION

The addition of preadmission testing and decolonization therapy to standard care would result in significant cost savings, even after accounting for variations in the model input values.

Persistent Staphylococcus aureus bacteremia: an analysis of risk factors and outcomes

BACKGROUND

Persistent Staphylococcus aureus bacteremia (pSAB) is an emerging problem among hospitalized patients. We studied key clinical characteristics and outcomes associated with pSAB to better define the epidemiological features of this increasingly recognized clinical entity.

METHODS

A retrospective case-control study of patients hospitalized with SAB between January 1, 2001, and September 30, 2004, was conducted to compare the clinical characteristics, management, and outcomes of patients with pSAB (> 7 days of bacteremia) with those of a cohort of patients with nonpersistent SAB (< 3 days of bacteremia). Patients with 4 to 6 days of bacteremia were excluded from the analysis. To detect a potential association between reduced susceptibility to vancomycin and persistent methicillin-resistant SAB, vancomycin susceptibilities were confirmed using standard dilution methods.

RESULTS

Eighty-four patients with pSAB and 152 patients with nonpersistent SAB were included in the analysis. Methicillin resistance (odds ratio [OR], 5.22; 95% confidence interval [CI], 2.63-10.38), intravascular catheter or other foreign body use (OR, 2.37; 95% CI, 1.11-3.96), chronic renal failure (OR, 2.08; 95% CI, 1.09-3.96), more than 2 sites of infection (OR, 3.31; 95% CI, 1.17-9.38), and infective endocarditis (OR, 10.30; 95% CI, 2.98-35.64) were independently associated with pSAB. The mean time to device removal was significantly longer in patients with pSAB than in patients with nonpersistent SAB (4.94 vs 1.64 days; P < .01). There was no evidence of reduced vancomycin susceptibility among persistent methicillin-resistant S aureus isolates. Clinical outcomes were significantly worse among patients with pSAB.

CONCLUSIONS

Many hospitalized patients may be at risk for pSAB. Aggressive attempts to minimize the risk of complications and poor outcomes associated with pSAB, such as early device removal, should be encouraged.

National trends in Staphylococcus aureus infection rates: impact on economic burden and mortality over a 6-year period (1998-2003)

BACKGROUND

We evaluated historical trends in the Staphylococcus aureus infection rate, economic burden, and mortality in US hospitals from 1998 through 2003.

METHODS

The Nationwide Inpatient Sample was used to assess trends over time of S. aureus infection during 1998-2003. Historical trends were determined for 5 strata of hospital stays, including all inpatient stays, surgical procedure stays, invasive cardiovascular surgical stays, invasive orthopedic surgical stays, and invasive neurosurgical stays.

RESULTS

During the 6-year study period from 1998 through 2003, the rate of S. aureus infection increased significantly for all inpatient stays (from 0.74% to 1.0%; annual percentage change (APC), 7.1%; P=.004), surgical stays (from 0.90% to 1.3%; APC, 7.9%; P=.001), and invasive orthopedic surgical stays (from 1.2% to 1.8%; APC, 9.3%; P<.001). For invasive neurosurgical stays, the rate of S. aureus infection did not change from 1998 to 2000 but increased at an annual rate of 11.0% from 2000 to 2003 (from 1.4% to 1.8%; P=.034). The total economic burden of S. aureus infection for hospitals also increased significantly for all stay types, with the annual percentage increase ranging from 9.2% to 17.9% (P<.05 for all). In 2003, the total economic burden of S. aureus infection was estimated to be $14.5 billion for all inpatient stays and $12.3 billion for surgical patient stays. However, there were significant decreases in the risk of S. aureus-related in-hospital mortality from 1998 to 2003 for all inpatient stays (from 7.1% to 5.6%; APC, -4.6%; P=.001) and for surgical stays (from 7.1% to 5.5%; APC, -4.6%; P=.002).

CONCLUSIONS

The inpatient S. aureus infection rate and economic burden of S. aureus infections for US hospitals increased substantially from 1998 to 2003, whereas the in-hospital mortality rate decreased.

Screening for extended-spectrum beta-lactamase-producing Enterobacteriaceae among high-risk patients and rates of subsequent bacteremia

BACKGROUND

Bloodstream infections due to extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae have been associated with increased hospital costs, length of stay, and patient mortality. However, the role of routine inpatient surveillance for ESBL colonization in predicting related infection is unclear.

METHODS

From 2000 through 2005, we screened 17,872 patients hospitalized in designated high-risk units for rectal colonization with vancomycin-resistant enterococci and ESBL-producing Enterobacteriaceae using a selective culture medium. In patients with a bloodstream infection due to ESBL-producing Enterobacteriaceae (ESBL-BI) during the study period, surveillance results were evaluated for evidence of antecedent ESBL-producing Enterobacteriaceae colonization.

RESULTS

The rate of ESBL-producing Enterobacteriaceae colonization doubled during the 6-year study period, increasing from 1.33% of high-risk patients in 2000 to 3.21% in 2005. Among patients with ESBL-producing Enterobacteriaceae colonization, 49.6% also carried vancomycin-resistant enterococci. The number of ESBL-BIs increased >4-fold in 5 years, from 9 cases in 2001 to 40 cases in 2005. Of 413 patients colonized with ESBL-producing Enterobacteriaceae, 35 (8.5%) developed a subsequent ESBL-BI. Of concern, more than one-half of all ESBL-BIs occurred in patients who were not screened. These 56 patients received a diagnosis of ESBL-BI in the emergency department, when hospitalized in low-risk medical units, or at transfer from an acute or long-term health care facility.

CONCLUSIONS

Colonization with ESBL-producing Enterobacteriaceae is increasing at a rapid rate, and routine rectal surveillance for ESBL-producing Enterobacteriaceae may have clinical implications. However, in our experience, over one-half of patients with an ESBL-BI did not undergo screening through our current surveillance measures. As a result, targeted screening for ESBL-producing Enterobacteriaceae among additional patient populations may be integral to future ESBL-BI prevention and management efforts.

Postpartum mastitis and community-acquired methicillin-resistant Staphylococcus aureus

This single-center, case-control study documents a relative increase in methicillin resistance among 48 cases of Staphylococcus aureus–associated postpartum mastitis during 1998–2005. Of 21 cases with methicillin resistance, 17 (81%) occurred in 2005. Twenty (95%) isolates contained the Staphylococcus cassette chromosome mec type IV gene; this suggests that the increase is due to community-acquired methicillin-resistant Staphylococcus aureus.

Legislative mandates for use of active surveillance cultures to screen for methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci: Position statement from the Joint SHEA and APIC Task Force

Legislation aimed at controlling antimicrobial-resistant pathogens through the use of active surveillance cultures to screen hospitalized patients has been introduced in at least 2 US states. In response to the proposed legislation, the Society for Healthcare Epidemiology of America (SHEA) and the Association for Professionals in Infection Control and Epidemiology, Inc., (APIC) have developed this joint position statement. Both organizations are dedicated to combating health care-associated infections with a wide array of methods, including the use of active surveillance cultures in appropriate circumstances. This position statement reviews the proposed legislation and the rationale for use of active surveillance cultures, examines the scientific evidence supporting the use of this strategy, and discusses a number of unresolved issues surrounding legislation mandating use of active surveillance cultures. The following 5 consensus points are offered. (1) Although reducing the burden of antimicrobial-resistant pathogens, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE), is of preeminent importance, the APIC and the SHEA do not support legislation to mandate use of active surveillance cultures to screen for MRSA, VRE, or other antimicrobial-resistant pathogens. (2) The SHEA and the APIC support the continued development, validation, and application of efficacious and cost-effective strategies for the prevention of infections caused by MRSA, VRE, and other antimicrobial-resistant and antimicrobial-susceptible pathogens. (3) The APIC and the SHEA welcome efforts by health care consumers, together with private, local, state, and federal policy makers, to focus attention on and formulate solutions for the growing problem of antimicrobial resistance and health care-associated infections. (4) The SHEA and the APIC support ongoing additional research to determine and optimize the appropriateness, utility, feasibility, and cost-effectiveness of using active surveillance cultures to screen both lower-risk and high-risk populations. (5) The APIC and the SHEA support stronger collaboration between state and local public health authorities and institutional infection prevention and control experts.

In vitro activities of various antimicrobials alone and in combination with tigecycline against carbapenem-intermediate or -resistant Acinetobacter baumannii

The activities of tigecycline alone and in combination with other antimicrobials are not well defined for carbapenem-intermediate or -resistant Acinetobacter baumannii (CIRA). Pharmacodynamic activity is even less well defined when clinically achievable serum concentrations are considered. Antimicrobial susceptibility testing of clinical CIRA isolates from 2001 to 2005 was performed by broth or agar dilution, as appropriate. Tigecycline concentrations were serially increased in time-kill studies with a representative of the most prevalent carbapenem-resistant clone (strain AA557; imipenem MIC, 64 mg/liter). The in vitro susceptibility of the strain was tested by time-kill studies in duplicate against the average free serum steady-state concentrations of tigecycline alone and in combination with various antimicrobials. Ninety-three CIRA isolates were tested and were found to have the following antimicrobial susceptibility profiles: tigecycline, MIC(50) of 1 mg/liter and MIC(90) of 2 mg/liter; minocycline, MIC(50) of 0.5 mg/liter and MIC(90) of 8 mg/liter; doxycycline, MIC(50) of 2 mg/liter and MIC(90) of > or =32 mg/liter; ampicillin-sulbactam, MIC(50) of 48 mg/liter and MIC(90) of 96 mg/liter; ciprofloxacin, MIC(50) of > or =16 mg/liter and MIC(90) of > or =16 mg/liter; rifampin, MIC(50) of 4 mg/liter and MIC(90) of 8 mg/liter; polymyxin B, MIC(50) of 1 mg/liter and MIC(90) of 1 mg/liter; amikacin, MIC(50) of 32 mg/liter and MIC(90) of > or =32 mg/liter; meropenem, MIC(50) of 16 mg/liter and MIC(90) of > or =128 mg/liter; and imipenem, MIC(50) of 4 mg/liter and MIC(90) of 64 mg/liter. Among the tetracyclines, the isolates were more susceptible to tigecycline than minocycline and doxycycline, according to FDA breakpoints (95%, 88%, and 71% of the isolates were susceptible to tigecycline, minocycline, and doxycycline, respectively). Concentration escalation studies with tigecycline revealed a maximal killing effect near the MIC, with no additional extent or rate of killing at concentrations 2x to 4x the MIC for tigecycline. Time-kill studies demonstrated indifference for tigecycline in combination with the antimicrobials tested. Polymyxin B, minocycline, and tigecycline are the most active antimicrobials in vitro against CIRA. Concentration escalation studies demonstrate that tigecycline may need to approach concentrations higher than those currently achieved in the bloodstream to adequately treat CIRA bloodstream infections. Future studies should evaluate these findings in vivo.

Discriminating Inhalational Anthrax From Community-Acquired Pneumonia Using Chest Radiograph Findings and a Clinical Algorithm

BACKGROUND

Limiting the effects of a large-scale bioterrorist anthrax attack will require rapid and accurate detection of the earliest victims. We undertook this study to improve physicians' ability to rapidly detect inhalational anthrax victims.

METHODS

We conducted a case-control study to compare chest radiograph findings from 47 patients from historical inhalational anthrax cases and 188 community-acquired pneumonia control subjects. We then used classification tree analyses to derive an algorithm of chest radiograph findings and clinical characteristics that accurately and explicitly discriminated between inhalational anthrax and community-acquired pneumonia.

RESULTS

Twenty-two of the 47 patients from historical inhalational anthrax cases (46.8%) had reported chest radiograph findings. All 22 case patients (100%) had mediastinal widening, pleural effusion, or both. However, 16 case patients (72.7%) also had infiltrates. In comparison, all 188 community-acquired control subjects had reported chest radiographs. Of these, 127 control subjects (67.6%) had infiltrates, 43 control subjects (22.9%) had pleural effusions, and 15 control subjects (8.0%) had mediastinal widening. A derived algorithm with three predictor variables (chest radiograph finding of mediastinal widening, altered mental status, and elevated hematocrit) is 100% sensitive (95% confidence interval [CI], 73.5 to 100) and 98.3% specific (95% CI, 95.1 to 99.6). The derivation process used 12 patients with inhalational anthrax and 177 control subjects with community-acquired pneumonia who had information available for all three variables.

CONCLUSIONS

There are significant chest radiograph differences between inhalational anthrax and community-acquired pneumonia, but none of the chest radiograph findings are both highly sensitive and highly specific. The derived clinical algorithm can improve physicians' ability to discriminate inhalational anthrax from community-acquired pneumonia, but its utility is limited to previously healthy individuals and its accuracy may be limited by missing values.

Improving the assessment of vancomycin-resistant enterococci by routine screening

BACKGROUND

As infection with vancomycin-resistant enterococci (VRE) increases in hospitals, knowledge about VRE reservoirs and improved accuracy of epidemiologic measures are needed. Many assessments underestimate incidence by including prevalent carriers in at-risk populations. Routine surveillance cultures can substantially improve prevalence and incidence estimates, and assessing the range of improvement across diverse units is important.

METHODS

We performed a retrospective cohort study using accurate at-risk populations to evaluate the range of benefit of admission and weekly surveillance cultures in detecting unrecognized VRE in 14 patient-care units.

RESULTS

We assessed 165 unit-months. The admission prevalence of VRE was 2.2%-27.2%, with admission surveillance providing 2.2-17-fold increased detection. Medical units were significantly more likely to admit VRE carriers than were surgical units. Monthly incidence was 0.8%-9.7%, with weekly surveillance providing 3.3-15.4-fold increased detection. The common practice of reporting incidence using the total number of patients, rather than patients at risk, underestimated incidence by one-third. Overall, routine surveillance prevented the misclassification of 43.0% (unit range, 0%-85.7%) of "incident" carriers on the basis of clinical cultures alone and increased VRE precaution days by 2.4-fold (unit range, 2.0-2.6-fold).

CONCLUSIONS

Routine surveillance markedly increases the detection of VRE, despite variability across patient-care units. Correct denominators prevent the substantial underestimation of incidence.

Impact of inactive empiric antimicrobial therapy on inpatient mortality and length of stay

The consequences of inactive empiric antimicrobial therapy are not well-described and may cause prolonged hospitalization or infection-related mortality. In vitro susceptibility results for 884 patients hospitalized at an academic medical center with gram-negative bloodstream infections (GNBI) from 2001 to 2003 were matched to antimicrobial orders within 24 h of culture. Clinical characteristics, organism, inpatient mortality, and length of stay after culture for patients with GNBI were compared between patients receiving active versus inactive empiric antimicrobial therapy. A total of 14.1% of patients with GNBI received inactive empiric therapy, defined as no antimicrobial therapy within 24 h of the culture active against the identified organism based on in vitro microbiology reports. Patients who received inactive therapy were more likely to be younger, to be infected with Pseudomonas aeruginosa, to have a nosocomial infection, and to receive antimicrobial monotherapy but less likely to be bacteremic with Escherichia coli or to have sepsis (P < 0.05). There were no significant differences in mortality between patients receiving active versus inactive empiric therapy (16.1% versus 13.6%, respectively) or in length of stay after positive culture (11.5 days versus 12.6 days, respectively). Only 45 patients had greater than 2 days of exposure to inactive therapy; however, 8/30 patients (26.7%) who never received active antimicrobial therapy died while in the hospital. Inactive empiric therapy was more common in healthier patients. Inactive antimicrobial therapy in the first 24 h did not significantly impact average outcomes for GNBI among hospitalized patients but may have caused harm to specific individuals.

The clinical impact of linezolid susceptibility reporting in patients with vancomycin-resistant enterococci

Linezolid remains a mainstay of therapy for vancomycin-resistant enterococci (VREs), but resistance has emerged. We describe a cohort of 20 patients with linezolid-intermediate or resistant VRE (LIRVRE) reported by Etest and disk diffusion testing, 18 of whom demonstrated linezolid susceptibility by agar dilution on further investigation. Patients with reported LIRVRE were matched based on culture site and enterococcal species to patients with linezolid-susceptible VRE (LSVRE) in a 1:3 ratio. Patients with reported LIRVRE developed more nosocomial infections (P = .04), had more central lines placed (P = .04), and underwent more computed tomography scans related to VRE infection (P = .02). Multivariate analysis revealed increased surgical procedures related to VRE infections (P = .008), increased linezolid use during hospital stay (P = .03), and delayed culture and susceptibility results compared with those with LSVRE (P = .006). Therefore, inaccurate detection and reporting of LIRVRE by disk diffusion and Etest is associated with increased patient morbidity and resource use.

Tigecycline: a new glycylcycline for treatment of serious infections

Tigecycline is a new semisynthetic glycylcycline for the treatment of serious infections. Of the glycylcyclines, tigecycline is the most studied and appears to hold promise as a new antimicrobial agent that can be administered as monotherapy to patients with many types of serious bacterial infections. For patients with serious infections, the initial choice for empirical therapy with broad-spectrum antibiotics is crucial, and, if the choice is inappropriate, it may have adverse consequences for the patient. Tigecycline has been designed to overcome many existing mechanisms of resistance among bacteria and confers broad antibiotic coverage against vancomycin-resistant enterococci, methicillin-resistant Staphylococcus aureus, and many species of multidrug-resistant gram-negative bacteria. Tigecycline has been efficacious and well tolerated in human clinical phase 2 studies, which warranted further evaluation of tigecycline in larger studies for treatment of many indications, including complicated skin and skin-structure infections, complicated intra-abdominal infections, and infections of the lower respiratory tract.

Peritoneal fluid penetration of tigecycline

OBJECTIVE

To describe the peritoneal fluid penetration of tigecycline.

CASE SUMMARY

A 33-year-old critically ill man who had undergone orthotopic liver and cadaveric renal transplant presented with sepsis. The patient required empiric antimicrobial coverage, continuous veno-venous hemofiltration, prolonged mechanical ventilation, tracheostomy placement, and maintenance immunosuppressive therapy. After multiple infections with multi-drug resistant pathogens, the patient developed vancomycin-resistant Enterococcus faecium peritonitis. Tigecycline 50 mg was administered every 12 hours, and ascites fluid drug concentrations were obtained. Drug concentrations in the peritoneal fluid were determined by high-performance liquid chromatography and revealed a tigecycline concentration of 0.074 microg/mL. Despite aggressive measures, the patient's condition continued to decline; he died 2 weeks after tigecycline initiation.

DISCUSSION

As of October 3, 2006, these are the first data to describe tigecycline peritoneal fluid penetration. Tigecycline was aggressively administered at twice the recommended dosage for overt liver failure in light of the severity of this patient's condition. A tigecycline peritoneal fluid concentration of 44-54% of serum concentration was calculated based on the patient's peritoneal fluid drug concentration and previously published serum concentrations from a similar population.

CONCLUSIONS

Peritoneal penetration of tigecycline was approximately 50% in this critically ill patient. Establishment of site-specific breakpoints for tigecycline may be necessary. Future studies will need to evaluate the penetration of tigecycline into peritoneal fluid and other tissues.

Applying antimicrobial pharmacodynamics to resistant gram-negative pathogens

PURPOSE

Guided antibiotic adjustment for the treatment of multidrug-resistant, gram-negative pathogens is explored.

SUMMARY

Multidrug-resistant pathogens are being isolated with increasing frequency, while the production of novel agents to circumvent resistance has slowed to a near halt. Hence, antimicrobial adjustment based on drug pharmacokinetic and pharmacodynamic properties has moved to the forefront of treatment. Pharmacodynamic principles for major classes of antimicrobials are reviewed, and the use of susceptibility reports to optimize pharmacodynamics to treat gram-negative infections is described. The need for the application of antimicrobial pharmacodynamics continues to grow as resistance to the agents becomes more common. Susceptibility reports, including antibiograms, and their limitations are briefly discussed. The resistance profiles of the beta-lactams (including carbapenems), aminoglycosides, fluoroquinolones, tetracyclines and glycylcyclines, and the polymyxins are reviewed, and the pharmacodynamic optimization of these profiles is explored.

CONCLUSION

Various mechanisms account for resistance of bacteria to antibiotics. The appropriate use of pharmacokinetics and pharmacodynamics can guide antibiotic therapy and enhance the likelihood of success.

A randomized, open-label, multicenter comparative study of the efficacy and safety of piperacillin-tazobactam and cefepime for the empirical treatment of febrile neutropenic episodes in patients with hematologic malignancies

BACKGROUND

The empirical treatment of febrile, neutropenic patients with cancer requires antibacterial regimens active against both gram-positive and gram-negative pathogens. This study was performed to demonstrate the noninferiority of monotherapy with piperacillin-tazobactam, compared with cefepime.

METHODS

We conducted a randomized-controlled, open-label, multicenter clinical trial among high-risk patients from 34 university-affiliated tertiary care medical centers in the United States, Canada, and Australia who were undergoing treatment for leukemia or hematopoietic stem cell transplantation and were hospitalized for empirical treatment of febrile neutropenic episodes. Patients received piperacillin-tazobactam (4.5 g every 6 h) or cefepime (2 g every 8 h) intravenously. The primary outcome was success (defined by defervescence without treatment modification) at 72 h of treatment, end of treatment, and test of cure in the modified intent-to-treat analysis. Secondary outcomes included time to defervescence, microbiological efficacy, the additional use of glycopeptide antibiotics, emergence of resistant bacteria, and safety.

RESULTS

For 528 subjects (265 received piperacillin-tazobactam and 263 received cefepime), success rates were 57.7% and 48.3%, respectively (P = .04) at the 72-h time point, 39.6% and 31.6% (P = .06) at end of treatment, and 26.8% and 20.5% (P = .11) at the test-of-cure visit. The analyses demonstrated noninferiority for piperacillin-tazobactam at all time points (P< or = .0001). Treatment with piperacillin-tazobactam was independently associated with treatment success in multivariate analysis (odds ratio, 1.65; 95% confidence interval, 1.04-2.64; P = .035). Both regimens were well tolerated.

CONCLUSIONS

This study demonstrates the noninferiority and safety of piperacillin-tazobactam monotherapy, compared with cefepime, for the empirical treatment of high-risk febrile neutropenic patients with cancer.

A multicenter intervention to prevent catheter-associated bloodstream infections

BACKGROUND

Education-based interventions can reduce the incidence of catheter-associated bloodstream infection. The generalizability of findings from single-center studies is limited.

OBJECTIVE

To assess the effect of a multicenter intervention to prevent catheter-associated bloodstream infections.

DESIGN

An observational study with a planned intervention.

SETTING

Twelve intensive care units and 1 bone marrow transplantation unit at 6 academic medical centers.

PATIENTS

Patients admitted during the study period.

INTERVENTION

Updates of written policies, distribution of a 9-page self-study module with accompanying pretest and posttest, didactic lectures, and incorporation into practice of evidence-based guidelines regarding central venous catheter (CVC) insertion and care.

MEASUREMENTS

Standard data collection tools and definitions were used to measure the process of care (ie, the proportion of nontunneled catheters inserted into the femoral vein and the condition of the CVC insertion site dressing for both tunneled and nontunneled catheters) and the incidence of catheter-associated bloodstream infection.

RESULTS

Between the preintervention period and the postintervention period, the percentage of CVCs inserted into the femoral vein decreased from 12.9% to 9.4% (relative ratio, 0.73; 95% confidence interval [CI], 0.61-0.88); the total proportion of catheter insertion site dressings properly dated increased from 26.6% to 34.4% (relative ratio, 1.29; 95% CI, 1.17-1.42), and the overall rate of catheter-associated bloodstream infections decreased from 11.2 to 8.9 infections per 1,000 catheter-days (relative rate, 0.79; 95% CI, 0.67-0.93). The effect of the intervention varied among individual units.

CONCLUSIONS

An education-based intervention that uses evidence-based practices can be successfully implemented in a diverse group of medical and surgical units and reduce catheter-associated bloodstream infection rates.

Active surveillance using electronic triggers to detect adverse events in hospitalized patients

BACKGROUND

Adverse events (AEs) occur with alarming frequency in health care and can have a significant impact on both patients and caregivers. There is a pressing need to understand better the frequency, nature, and etiology of AEs, but currently available methodologies to identify AEs have significant limitations. We hypothesized that it would be possible to design a method to conduct real time active surveillance and conducted a pilot study to identify adverse events and medical errors.

METHODS

Records were selected based on 21 electronically obtained triggers, including abnormal laboratory values and high risk and antidote medications. Triggers were chosen based on their expected potential to signal AEs occurring during hospital admissions. Each AE was rated for preventability and severity and categorized by type of event. Reviews were performed by an interdisciplinary patient safety team.

RESULTS

Over a 3 month period 327 medical records were reviewed; at least one AE or medical error was identified in 243 (74%). There were 163 preventable AEs (events in which there was a medical error that resulted in patient harm) and 138 medical errors that did not lead to patient harm. Interventions to prevent or ameliorate harm were made following review of the medical records of 47 patients.

CONCLUSIONS

This methodology of active surveillance allows for the identification and assessment of adverse events among hospitalized patients. It provides a unique opportunity to review events at or near the time of their occurrence and to intervene and prevent harm.

Assessment of materials commonly utilized in health care: implications for bacterial survival and transmission

BACKGROUND

Contaminated environmental surfaces, equipment, and health care workers' hands have been linked to outbreaks of infection or colonization because of vancomycin-resistant enterococci (VRE) and Pseudomonas aeruginosa (PSAE). Upholstery, walls, and flooring may enhance bacterial survival, providing infectious reservoirs.

OBJECTIVES

Investigate recovery of VRE and PSAE, determine efficacy of disinfection, and evaluate VRE transmission from surfaces.

METHODS

Upholstery, flooring, and wall coverings were inoculated with VRE and PSAE and assessed for recovery at 24 hours, 72 hours, and 7 days. Inoculated surfaces were cleaned utilizing manufacturers' recommendations of natural, commercial, or hospital-approved products and methods, and samples were obtained. To assess potential for transmission, volunteers touched VRE-inoculated surfaces and imprinted palms onto contact-impression plates.

RESULTS

Twenty-four hours following inoculation, all surfaces had recovery of VRE; 13 (92.9%) of 14 surfaces had persistent PSAE. After cleaning, VRE was recovered from 7 (50%) surfaces, PSAE from 5 (35.7%) surfaces. After inoculation followed by palmar contact, VRE was recovered from all surfaces touched.

CONCLUSION

Bacteria commonly encountered in hospitals are capable of prolonged survival and may promote cross transmission. Selection of surfaces for health care environments should include product application and complexity of manufacturers' recommendations for disinfection. Recovery of organisms on surfaces and hands emphasizes importance of hand hygiene compliance prior to patient contact.

Potential Impact of Vancomycin Pulmonary Distribution on Treatment Outcomes in Patients with Methicillin-ResistantStaphylococcus aureusPneumonia

Vancomycin as the drug of choice for treatment of methicillin-resistant Staphylococcus aureus (MRSA) pneumonia has been called into question on the basis of therapeutic failures. In patients with MRSA pneumonia, treatment failures are probably due to the complex interplay of variables affecting the host-antimicrobial-pathogen interrelationship. However, it has been suggested that decreased penetration of vancomycin into the lungs may contribute. This review explores physiochemical and physiologic variables that affect pulmonary penetration and describes methods used in quantifying pulmonary vancomycin concentrations. Most important, findings are evaluated in the clinical context of the chemotherapeutic options available for treatment of MRSA pneumonia. The possibility of increased serum vancomycin concentrations as a method to optimize current treatment outcomes is also explored.

Efficacy and safety of scheduled dosing of opioid analgesics: a quality improvement study

Scheduled dosing of opioids is believed to provide more effective analgesia when compared to as needed (PRN) administration of the drug; however, few studies have evaluated the value of this approach. Therefore, a quality improvement study was conducted to determine the efficacy and safety of scheduled dosing of opioid analgesics, using a 2-group parallel design. One medical unit in a large urban academic medical center employed scheduled dosing, whereas a comparable unit used PRN dosing. The primary outcome indicators included pain intensity ratings and opioid doses, along with adverse events. Scheduled dosing was associated with decreased pain intensity ratings. There were no statistically significant differences in the amount of opioid ordered, or the amount administered when comparing scheduled vs. PRN dosing. However, when the amount of opioid given was expressed as a percentage of the amount ordered, the difference between scheduled (70.8%) and PRN (38%) dosing was statistically significant (P = .0001). There was no difference in adverse events between the 2 groups. These findings suggest that scheduled dosing of opioids in an inpatient medical population provides improved analgesia with no increased risk of adverse events.

PERSPECTIVE

Scheduled dosing of opioids in an inpatient medical population improves analgesia, theoretically by overcoming barriers to drug administration, as well as providing more stable plasma levels of the opioid.

The Burden of Staphylococcus aureus Infections on Hospitals in the United States

BACKGROUND

Previous studies have investigated the impact of Staphylococcus aureus infections on individual hospitals, but to date, no study using nationally representative data has estimated this burden.

METHODS

This is a retrospective analysis of the 2000 and 2001 editions of the Agency for Healthcare Research and Quality's Nationwide Inpatient Sample database, which represents a stratified 20% sample of hospitals in the United States. All inpatient discharge data from 994 hospitals in 28 states during 2000 and from 986 hospitals in 33 states during 2001, representing approximately 14 million inpatient stays, were analyzed to determine the association of S aureus infections with length of stay, total charges, and in-hospital mortality.

RESULTS

Staphylococcus aureus infection was reported as a discharge diagnosis for 0.8% of all hospital inpatients, or 292 045 stays per year. Inpatients with S aureus infection had, on average, 3 times the length of hospital stay (14.3 vs 4.5 days; P<.001), 3 times the total charges (48,824 US dollars vs 14,141 US dollars; P<.001), and 5 times the risk of in-hospital death (11.2% vs 2.3%; P<.001) than inpatients without this infection. Even when controlling for hospital fixed effects and for patient differences in diagnosis-related groups, age, sex, race, and comorbidities, the differences in mean length of stay, total charges, and mortality were significantly higher for hospitalizations associated with S aureus.

CONCLUSIONS

Staphylococcus aureus infections represent a considerable burden to US hospitals, particularly among high-risk patient populations. The potential benefits to hospitals in terms of reduced use of resources and costs as well as improved outcomes from preventing S aureus infections are significant.

Enhanced identification of postoperative infections among inpatients

Monitoring antimicrobial exposure and diagnosis codes for certain procedures identifies more postoperative infections than routine surveillance methods.

We evaluated antimicrobial exposure, discharge diagnoses, or both to identify surgical site infections (SSI). This retrospective cohort study in 13 hospitals involved weighted, random samples of records from 8,739 coronary artery bypass graft (CABG) procedures, 7,399 cesarean deliveries, and 6,175 breast procedures. We compared routine surveillance to detection through inpatient antimicrobial exposure (>9 days for CABG, >2 days for cesareans, and >6 days for breast procedures), discharge diagnoses, or both. Together, all methods identified SSI after 7.4% of CABG, 5.0% of cesareans, and 2.0% of breast procedures. Antimicrobial exposure had the highest sensitivity, 88%–91%, compared with routine surveillance, 38%–64%. Diagnosis codes improved sensitivity of detection of antimicrobial exposure after cesareans. Record review confirmed SSI after 31% to 38% of procedures that met antimicrobial surveillance criteria. Sufficient antimicrobial exposure days, together with diagnosis codes for cesareans, identified more postoperative SSI than routine surveillance methods. This screening method was efficient, readily standardized, and suitable for most hospitals.

Emerging incidence of Enterococcus faecium among hospital isolates (1993 to 2002)

Historically, most clinical microbiology laboratories report that 80 to 90% of enterococci are Enterococcus faecalis, whereas E. faecium accounts for 5 to 10% of isolates. At our medical center from 1993 to 2002, we evaluated the percentages of E. faecium among all enterococcal isolates and the percentages of E. faecium isolates that were vancomycin resistant. Over this 10-year period, the percentage of enterococci that were identified as E. faecium increased from 12.7 to 22.2% (P < 0.001) and the proportion of E. faecium that was vancomycin resistant increased from 28.9 to 72.4% (P < 0.001). Both the percentage of E. faecium among the enterococci and the proportion of vancomycin-resistant E. faecium increased significantly over this 10-year period.

Multidrug-resistant Pseudomonas aeruginosa cholangitis after endoscopic retrograde cholangiopancreatography: failure of routine endoscope cultures to prevent an outbreak

BACKGROUND

Nosocomial infections due to medical devices are of increasing concern to infection control practitioners. Attempts to prevent such infections have included surveillance cultures of endoscopes and bronchoscopes. In July 2002, the infectious disease consultation service was asked to see three patients with sepsis due to multidrug-resistant Pseudomonas aeruginosa after endoscopic retrograde cholangiopancreatography (ERCP).

OBJECTIVE

To describe an outbreak of multidrug-resistant P. aeruginosa sepsis after ERCP at an institution that performs routine surveillance cultures of endoscopes.

DESIGN

A traditional outbreak investigation supplemented by pulsed-field gel electrophoresis (PFGE) was undertaken, including a case-control analysis based on the hypothesis that all infected individuals had their ERCP performed with the same endoscope.

SETTING

A tertiary-care academic medical center.

RESULTS

The case-control analysis confirmed the hypothesis that undergoing ERCP with the implicated endoscope was associated with a culture positive for Pseudomonas (P = .01). The available strains were identical by PFGE. This outbreak occurred despite a negative surveillance culture of the implicated endoscope 1 month earlier.

CONCLUSIONS

Infectious morbidity can occur after endoscopy despite negative surveillance cultures. The practice of routine endoscope cultures does not prevent device-related infectious morbidity.