National Healthcare Safety Network Criteria Research Articles

Antibiotic consumption and ventilator-associated pneumonia rates, some parallelism but some discrepancies.

Ventilator-associated pneumonia (VAP) is a common infection in intensive care units (ICUs) but its clinical definition is neither sensitive nor specific and lacks accuracy and objectivity. New defining criteria were proposed in 2013 by the National Healthcare Safety Network (NHSN) in order to more accurately conduct surveillance and track prevention progress. Although there is a consistent trend towards a decrease in VAP incidence during the last decade, significant differences in VAP rates have been reported and are persistently lower in NHSN and other American reports (0.0 to 4.4 VAP per 1,000 ventilator-days in 2012) compared to the European Centre for Disease Prevention and Control (ECDC) data (10 VAP per 1,000 ventilator-days in 2014). In the United States, VAP has been proposed as an indicator of quality of care in public reporting, and the threat of financial penalties for this diagnosis has put pressure on hospitals to minimize VAP rates that may lead to artificial lower values, independently of patient care. Although prevention bundles may contribute for encouraging reductions in VAP incidence, both pathophysiologic and epidemiologic factors preclude a zero-VAP rate. It would be expected from the trend of reduction of VAP incidence that the consumption of antibiotics would also decrease in particular in those hospitals with lowest VAP rates. However, ICU reports show a steadily use of antibiotics for nosocomial pneumonia in 15% of patients and both ECDC and NHSN data on antibiotic consumption showed no significant trend. Knowledge of bacterial epidemiology and resistance profiles for each ICU has great relevance in order to understand trends of antibiotic use. The new NHSN criteria provide a more objective and quantitative data based VAP definition, including an antibiotic administration criterion, allowing, in theory, a more comprehensive assessment and a reportable benchmark of the observed VAP and antibiotic consumption variability.

Evidence-Based Bundles and Cesarean Delivery Surgical Site Infections

To estimate the association of implementation of evidence-based bundles with surgical site infection rates after cesarean delivery. We searched MEDLINE through PubMed, EMBASE, Scopus, the Cochrane Database of Systematic Reviews, Google Scholar, and ClinicalTrials.gov. We searched electronic databases for randomized controlled trials and observational studies comparing evidence-based infection prevention bundles for cesarean delivery, defined as implementation of three or more processes proven to prevent surgical site infection such as chlorhexidine skin preparation, antibiotic prophylaxis, and hair clipping, with usual care. The primary outcome was overall surgical site infection, defined using Centers for Disease Control and Prevention's National Healthcare Safety Network criteria. Secondary outcomes were superficial or deep surgical site infection and endometritis. Quality of studies and heterogeneity were assessed using validated measures. Pooled relative risks (RRs) with 95% CIs were calculated using random-effects models. Numbers needed to treat were estimated for outcomes with significant reduction. We found no randomized controlled trials. Fourteen preintervention and postintervention studies met inclusion criteria. Eight were full-text articles, and six were published abstracts. Quality of most of the primary studies was adequate with regard to the intervention, but modest in terms of implementation. The rate of surgical site infection was significantly lower after implementing an evidence-based bundle (14 studies: pooled rates 6.2% baseline compared with 2.0% intervention, pooled RR 0.33, 95% CI 0.25-0.43, number needed to treat=24). Evidence-based bundles were also associated with a lower rate of superficial or deep surgical site infection (six studies: pooled rate 5.9% baseline compared with 1.1% intervention, pooled RR 0.19, 95% CI 0.12-0.32, number needed to treat=21). The rate of endometritis was low at baseline and not significantly different after intervention (six studies: pooled rate 1.3% baseline compared with 0.9% intervention, pooled RR 0.57, 95% CI 0.31-1.06). Evidence-based bundles are associated with a significant reduction in surgical site infection after cesarean delivery.

Assessment of the accuracy and consistency in the application of standardized surveillance definitions: A summary of the American Journal of Infection Control and National Healthcare Safety Network case studies, 2010-2016

The Centers for Disease Control and Prevention (CDC) National Healthcare Safety Network (NHSN) surveillance definitions are the most widely used criteria for health care-associated infection (HAI) surveillance. NHSN participants agree to conduct surveillance in accordance with the NHSN protocol and criteria. To assess the application of these standardized surveillance specifications and offer infection preventionists (IPs) opportunities for ongoing education, a series of case studies, with questions related to NHSN definitions and criteria were published. Beginning in 2010, case studies with multiple-choice questions based on standard surveillance criteria and protocols were written and published in the American Journal of Infection Control with a link to an online survey. Participants anonymously submitted their responses before receiving the correct answers. The 22 case studies had 7,950 respondents who provided 27,790 responses to 75 questions during the first 6 years. Correct responses were selected 62.5% of the time (17,376 out of 27,290), but ranged widely (16%-87%). In a subset analysis, 93% of participants self-identified as IPs (3,387 out of 3,640), 4.5% were public health professionals (163 out of 3,640), and 2.5% were physicians (90 out of 3,640). IPs responded correctly (62%) more often than physicians (55%) (P = .006). Among a cohort of voluntary participants, accurate application of surveillance criteria to case studies was suboptimal, highlighting the need for continuing education, competency development, and auditing.

The role of a surveillance programme for intro-ducing peripherally inserted central catheters: a 2-year observational study in an academic hospital.

In our hospital, a previous attempt to introduce peripherally inserted central catheters (PICC) was aborted after a nonsystematic approach, seemingly accompanied by high rates of complications. The goal of this new interdisciplinary project was to introduce PICCs in an academic hospital, with an embedded interdisciplinary surveillance programme for both infectious and noninfectious outcomes. We prospectively collected data for this surveillance study from all patients who underwent PICC insertion from 1 January 2014 and had the catheter removed by 31 December 2015 in our 950-bed academic hospital (Bern University Hospital, Switzerland). Infectious complications were defined according to Centers for Disease Control and Prevention / National Healthcare Safety Network criteria. PICCs were restricted to cancer and infectious disease patients, and were followed up irrespective of the management setting (inpatient, outpatient or intermittently hospitalised after insertion). An interdisciplinary team reviewed the outcomes on a routine basis and discussed changes to the process to improve outcomes, if necessary. One hundred and thirty-five PICCs were inserted in 124 patients, the majority of whom were patients from the medical oncology department (n = 107, 86.3%). Indications for PICC insertion included: chemotherapy (n = 97, 71.9%), antibiotic therapy (n = 24, 17.8%), total parenteral nutrition (n = 8, 5.9%), blood product transfusion (n = 4, 3.0%) and palliative care (n = 2, 1.5%). During a total of 10 402 catheter-days (median dwell time 62 days), there were five central line-associated bloodstream infections, including one mucosal barrier injury laboratory-confirmed bloodstream infection and two exit-site infections, yielding incidence rates of 0.48 and 0.19 infections per 1000 catheter-days, respectively. Incidence rates were 0.67 per 1000 catheter-days (n = 7) for radiologically documented deep venous thrombosis, 0.96 (n = 10) for tip dislocation and 0.67 (n = 7) for catheter occlusion. The overall rate of complications was 4.5 per 1000 catheter-days. Seventeen catheters (12.6%) were removed because of any complication. We successfully introduced PICCs in an academic hospital by implementing a systematic surveillance programme for complications. Both infectious and noninfectious complications were rare. Infection prevention specialists should be actively involved during the introduction of new intravascular devices in order to provide quality indicators and assure patient safety.

Perioperative participation of orthopedic patients and surgical staff in a nasal decolonization intervention to reduce Staphylococcus spp surgical site infections

With the goal of reducing rates of surgical site infections in our spine patients, we initiated a trial to investigate the impact of adding perisurgical nasal decolonization involving patients and surgical and nursing staff. We combined immediate presurgical application of a nonantibiotic alcohol-based nasal antiseptic with existing chlorhexidine bath or wipes in a comprehensive pre- and postoperative decolonization protocol. Mean infection rates were significantly decreased by 81% from 1.76 to 0.33 per 100 surgeries during the 15-month trial, when compared with the prior 9-month baseline.

Factors Associated with Fever in Intracerebral Hemorrhage

Fever is common in patients with intracerebral hemorrhage (ICH). We sought to identify predictors of fever in patients hospitalized with ICH, and compare infectious fever with noninfectious fever. A retrospective review on consecutive spontaneous ICH patients from April 2009 to March 2010 was performed. Fever was defined as temperature 100.9°F or higher and attributed to infectious versus noninfectious etiology, based upon the National Healthcare Safety Network criteria. Univariate analysis and multivariable logistic regression model were used to determine factors associated with fever and with infection. Among the 351 ICH patients, 136 (39%) developed fever. Factors associated with fever included mean ICH volume, intraventricular hemorrhage (IVH), external ventricular drain (EVD) placement or surgical evacuation, positive microbial cultures, longer length of stay (LOS), and higher in-hospital mortality. Among patients with fever, 96 (71%) were noninfectious and 40 (29%) were infectious. Infectious fever was associated with higher LOS. Noninfectious fever was associated with higher in-hospital mortality. In multivariable analysis, ICH volume (OR = 1.01, P = .04), IVH (OR = 2.0, P = .03), EVD (OR = 3.7, P < .0001), and surgical evacuation (OR = 6.78, P < .0001) were significant predictors of fever. Infectious fever (OR = 5.26, P = .004), EVD (OR = 4.86, P = .01), and surgical evacuation (OR = 4.77, P = .04) correlated with prolonged LOS when dichotomized using a median of 15 days. Fever is common in ICH patients and is not associated with a clear infectious etiology in the majority of patients. Patients with noninfectious fever have higher in-hospital mortality, but survivors have shorter LOS. Further studies are warranted to better understand fevers in ICH.

Multicenter prospective study on device-associated infection rates and bacterial resistance in intensive care units of Venezuela: International Nosocomial Infection Control Consortium (INICC) findings.

Device-associated healthcare-acquired infections (DA-HAI) pose a threat to patient safety in the intensive care unit (ICU). A DA-HAI surveillance study was conducted by the International Nosocomial Infection Control Consortium (INICC) in two adult medical/surgical ICUs at two hospitals in Caracas, Venezuela, in different periods from March 2008 to April 2015, using the US Centers for Disease Control and Prevention's National Healthcare Safety Network (CDC/NHSN) definitions and criteria, and INICC methods. We followed 1041 ICU patients for 4632 bed days. Central line-associated bloodstream infection (CLABSI) rate was 5.1 per 1000 central line days, ventilator-associated pneumonia (VAP) rate was 7.2 per 1000 mechanical ventilator days, and catheter-associated urinary tract infection (CAUTI) rate was 3.9 per 1000 urinary catheter days, all similar to or lower than INICC rates (4.9 [CLABSI]; 16.5 [VAP]; 5.3 [CAUTI]), and higher than CDC/NHSN rates (0.8 [CLABSI]; 1.1 [VAP]; and 1.3 [CAUTI]). Device utilization ratios were higher than INICC and CDC/NHSN rates, except for urinary catheter, which was similar to INICC. Extra length of stay was 8 days for patients with CLABSI, 9.6 for VAP and 5.7 days for CAUTI. Additional crude mortality was 3.0% for CLABSI, 4.4% for VAP, and 16.9% for CAUTI. DA-HAI rates in our ICUs are higher than CDC/NSHN's and similar to or lower than INICC international rates.

Body mass index greater than 35 is associated with severe Clostridium difficile infection.

Obesity has been implicated in the acquisition of Clostridium difficile infections (CDI), however, no study has investigated whether there is a correlation between body mass index (BMI) and CDI severity. To determine whether obesity, as measured by BMI correlates with severe hospital-onset or community-onset CDI. Patients admitted with CDI at a tertiary-care center from January 2013 to June 2015 were identified. The cohort was stratified by onset of disease using the National Healthcare Safety Network criteria, and by severity using the 2013 American College of Gastroenterology guidelines. Multivariate logistic regression was used to determine independent predictors of severe CDI. A total of 196 met the inclusion criteria, of which 57.1% (112) met criteria for severe disease. Overall, BMI >35 kg/m2 was 1.7-fold more likely to be associated with severe CDI compared to a BMI 20-35 kg/m2 (P < 0.005), and was an independent predictor of severe CDI (P = 0.038). In patients with community-onset-CDI and hospital-onset-CDI, a BMI >35 kg/m2 was associated with a 1.96-fold and 1.48 greater rate of severe CDI compared to a BMI 20-35 kg/m2 (P = 0.004 and 0.048), and was an independent predictor of severe CDI in these cohorts (P = 0.039 and 0.027) respectively. This study has identified an association between body mass index and Clostridium difficile infection severity. A BMI>35 kg/m2 is an independent risk factor for severe community-onset and hospital-onset Clostridium difficile infections.

Prospective observational study on central line-associated bloodstream infections and central venous catheter occlusions using a negative displacement connector with an alcohol disinfecting cap.

Major complications of central venous catheter (CVC) use include bloodstream infection and occlusion. We performed a prospective, observational study to determine the rate of central line-associated bloodstream infection (CLABSI) and CVC occlusion using a negative displacement connector with an alcohol disinfecting cap. Patients were followed from the time of CVC insertion through 2 days after removal, at the time of hospital discharge if there was no documentation of removal, or 90 days after the insertion of the CVC if it was not removed. CLABSI was defined using National Healthcare Safety Network criteria. Data for evidence of lumen occlusions were extracted from the electronic health record. Direct observations were performed to assess adherence to hospital policy regarding CVC insertion practice. A total of 2,512 catheters from 2,264 patients were enrolled for this study. There were 21 CLABSIs (0.84%; 95% confidence interval [CI], 0.48%-1.19%; 0.62 per 1,000 line days) and 378 occlusions (15.05%; 95% CI, 13.65%-16.45%; 11.23 per 1,000 line days). Eighty-five direct observations demonstrated insertion protocol adherence in 881 of 925 (95.24%; 95% CI, 93.87%-96.61%) measured criteria. Lines placed following a standardized protocol using a negative displacement connector with an alcohol cap have low rates of infection compared with historically published findings. We also established that the occlusion rate is >15-fold the CLABSI rate.

Improving Risk Adjustment Above Current Centers for Disease Control and Prevention Methodology Using Electronically Available Comorbid Conditions.

OBJECTIVE To identify comorbid conditions associated with surgical site infection (SSI) among patients undergoing renal transplantation and improve existing risk adjustment methodology used by the Centers for Disease Control and Prevention National Healthcare Safety Network (NHSN). PATIENTS Patients (≥18 years) who underwent renal transplantation at University of Maryland Medical Center January 1, 2010-December 31, 2011. METHODS Trained infection preventionists reviewed medical records to identify surgical site infections that developed within 30 days after transplantation, using NHSN criteria. Patient demographic characteristics and risk factors for surgical site infections were identified through a central data repository. International Statistical Classification of Disease, Ninth Revision, Clinical Modification codes were used to analyze individual component comorbid conditions and calculate the Charlson and Elixhauser comorbidity indices. These indices were compared with the current NHSN risk adjustment methodology. RESULTS A total of 441 patients were included in the final cohort. In bivariate analysis, the Charlson components of cerebrovascular disease, peripheral vascular disease, and rheumatologic disorders and Elixhauser components of obesity, rheumatoid arthritis, and weight loss were significantly associated with the outcome. A model utilizing the variables from the NHSN methodology had a c-statistic of 0.56 (95% CI, 0.48-0.63), whereas a model that also included comorbidities from the Charlson and Elixhauser indices had a c-statistic of 0.65 (95% CI, 0.58-0.73). The model with all 3 risk adjustment scores performed best and was statistically different from the NHSN model alone, demonstrated by improvement in the c statistic (0.65 vs 0.56). CONCLUSION Risk adjustment models should incorporate electronically available comorbid conditions. Infect Control Hosp Epidemiol 2016;1-6.

Surgical Site Infections Following Pediatric Ambulatory Surgery: An Epidemiologic Analysis.

OBJECTIVE To identify surgical site infection (SSI) rates following pediatric ambulatory surgery, SSI outcomes and risk factors, and sensitivity and specificity of SSI administrative billing codes. DESIGN Retrospective chart review of pediatric ambulatory surgeries with International Classification of Disease, Ninth Revision (ICD-9) codes for SSI, and a systematic random sampling of 5% of surgeries without SSI ICD-9 codes, all adjudicated for SSI on the basis of an ambulatory-adapted National Healthcare Safety Network definition. SETTING Urban pediatric tertiary care center April 1, 2009-March 31, 2014. METHODS SSI rates and sensitivity and specificity of ICD-9 codes were estimated using sampling design, and risk factors were analyzed in case-rest of cohort, and case-control, designs. RESULTS In 15,448 pediatric ambulatory surgeries, 34 patients had ICD-9 codes for SSI and 25 met the adapted National Healthcare Safety Network criteria. One additional SSI was identified with systematic random sampling. The SSI rate following pediatric ambulatory surgery was 2.9 per 1,000 surgeries (95% CI, 1.2-6.9). Otolaryngology surgeries demonstrated significantly lower SSI rates compared with endocrine (P=.001), integumentary (P=.001), male genital (P<.0001), and respiratory (P=.01) surgeries. Almost half of patients with an SSI were admitted, 88% received antibiotics, and 15% returned to the operating room. No risk factors were associated with SSI. The sensitivity of ICD-9 codes for SSI following ambulatory surgery was 55.31% (95% CI, 12.69%-91.33%) and specificity was 99.94% (99.89%-99.97%). CONCLUSIONS SSI following pediatric ambulatory surgery occurs at an appreciable rate and conveys morbidity on children. Infect Control Hosp Epidemiol 2016;37:931-938.

The impact of implementing multifaceted interventions on the prevention of ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) is a frequent hospital acquired infections among intensive care unit patients. The Institute for Healthcare Improvement has suggested a "care bundle" approach for the prevention of VAP. This report describes the effects of implementing this strategy on VAP rates. All mechanically ventilated patients admitted to the intensive care unit between 2008 and 2013 were prospectively followed for VAP development according to the National Healthcare Safety Network criteria. In 2011, a 7-element care bundle was implemented, including head-of-bed elevation 30°-45°, daily sedation vacation and assessment for extubation, peptic ulcer disease prophylaxis, deep vein thrombosis prophylaxis, oral care with chlorhexidine, endotracheal intubation with in-line suction and subglottic suctioning, and maintenance of endotracheal tube cuff pressure at 20-30 mmHg. The bundle compliance and VAP rates were then followed. A total of 3665 patients received mechanical ventilation, and there were 9445 monitored observations for bundle compliance. The total bundle compliance before and after initiation of the VAP team was 90.7% and 94.2%, respectively (P < .001). The number of VAP episodes decreased from 144 during 2008-2010 to only 14 during 2011-2013 (P < .0001). The rate of VAP decreased from 8.6 per 1000 ventilator-days to 2.0 per 1000 ventilator-days (P < .0001) after implementation of the care bundle. This study suggests that systematic implementation of a multidisciplinary team approach can reduce the incidence of VAP. Further sustained improvement requires persistent vigilant inspections.

Abstract WP371: Characteristics of Fever in Intracerebral Hemorrhage

Introduction: Fever in intracerebral hemorrhage (ICH) patients can be due to infectious or noninfectious etiology, including central mechanisms. We sought to compare patients with ICH and infectious fever to those with noninfectious fever. Methods: Among 351 consecutive primary ICH patients admitted to our institution from April 2009 to March 2010, 136 (39%) developed fever. Fever was defined as temperature &gt; 100.9°F during hospitalization. Cases were reviewed to determine if the patient had fever due to infectious versus noninfectious etiology. The diagnosis of infection was based on results of microbial cultures and National Healthcare Safety Network criteria. Other data collected included age, sex, maximum temperature (Tmax), medical history, ICH location, intraventricular hemorrhage (IVH), ICH volume as measured by standard ABC/2 bedside calculation, external ventricular drain (EVD) placement, surgical evacuation, length of stay (LOS), and inpatient mortality. Univariate analysis and multivariable logistic regression model were used to determine characteristics associated with infection status. Results: Among the 136 ICH patients with fever, 96 (71%) had noninfectious fever and 40 (29%) had infectious fever. In the univariate analysis, patients with infectious fever did not differ from patients with noninfectious fever with respect to age (61.3 vs 60.1 years, p 0.6), female sex (40% vs 48%, p 0.8), Tmax (102.2 vs 102.2°F, p 0.96), IVH (60% vs 71%, p 0.23), ICH volume (42 vs 40 cc, p 0.8), EVD placement (48% vs 51%, p 0.85), or surgical evacuation (30% vs 29%, p 1.0). Infectious fever was significantly associated with higher LOS (18.2 vs 11.1 days, p &lt;0.001), and this remained significant in survivors (18.6 vs 14.2 days, p 0.01). Noninfectious fever was associated with significantly higher inpatient mortality (35% vs 8%, p 0.0006). In multivariate analysis, infectious fever significantly correlated with prolonged LOS in survivors when dichotomized using a median of 15 days (OR 5.37, p 0.003). Conclusions: Patients with ICH who develop fever associated with an infectious etiology have longer LOS but lower in-hospital mortality. Further studies are warranted to understand fever in ICH patients.

Infection and readmission rate of cardiac implantable electronic device insertions: An observational single center study

Infection is one of the most serious complications following surgical placement of cardiac implantable electronic devices (CIEDs). Infection prevention efforts are necessary in reducing CIED infectious outcomes. These devices, however, are commonly inserted in higher risk patients, which may explain the ongoing risk of surgical site infection (SSI) in this population. The rates of CIED infection and utilization vary widely in the literature. The definitions of infection may also vary between clinical definitions and the National Healthcare Safety Network (NHSN) criteria. The primary objective of this study was to review patient data to identify risk factors for infection and readmission after CIED placement at an academic medical center. The secondary objectives were to compare the rates of SSI identified by NHSN criteria compared to that obtained by applying clinical infection definitions. The overall rate of infection (SSI) was 1.9%, which was identical in both the clinical definition and NHSN reported data. The 30 day readmission rate and the 90 day readmission rate were 12.7% and 25.6% respectively with the most readmissions related to the patients' underlying medical conditions. A lower ejection fraction (EF) was identified as an independent risk factor for readmission, inpatient procedures, smoking and device infection were also significantly associated with readmission after CIED insertion.

Treatment for Positive Urine Cultures in Hospitalized Adults: A Survey of Prevalence and Risk Factors in 3 Medical Centers.

Antibiotic treatment for asymptomatic bacteriuria (ASB) is prevalent but often contrary to published guidelines. To evaluate risk factors for treatment of ASB. Retrospective observational study. A tertiary academic hospital, county hospital, and community hospital. Hospitalized adults with bacteriuria. Patients without documented symptoms of urinary tract infection per Infectious Diseases Society of America (IDSA) criteria were classified as ASB. We examined ASB treatment risk factors as well as broad-spectrum antibiotic usage and quantified diagnostic concordance between IDSA and National Healthcare Safety Network criteria. Among 300 patients with bacteriuria, ASB was present in 71% by IDSA criteria. By National Healthcare Safety Network criteria, 71% of patients had ASB; within-patient diagnostic concordance with IDSA was moderate (kappa, 0.52). After excluding those given antibiotics for nonurinary indications, antibiotics were given to 38% (62/164) with ASB. Factors significantly associated with ASB treatment were elevated urine white cell count (65 vs 24 white blood cells per high-powered field, P<.01), hospital identity (hospital C vs A, odds ratio, 0.34 [95% CI, 0.14-0.80], P =.01), presence of leukocyte esterase (5.48 [2.35-12.79], P<.01), presence of nitrites (2.45 [1.11-5.41], P=.03), and Escherichia coli on culture (2.4 [1.2-4.7], P=.01). Of patients treated for ASB, broad-spectrum antibiotics were used in 84%. ASB treatment was prevalent across settings and contributed to broad-spectrum antibiotic use. Associating abnormal urinalysis results with the need for antibiotic treatment regardless of symptoms may drive unnecessary antibiotic use.

The impact of onset time on the isolated pathogens and outcomes in ventilator associated pneumonia.

Several guidelines base the empirical therapy of ventilator-associated pneumonia (VAP) on the time of onset. However, there is emerging evidence that the isolated microorganisms may be similar regardless of onset time. This study evaluated the characteristics and outcomes of VAP with different onset times. All of the mechanically ventilated patients admitted to the ICU of a 900-bed tertiary-care hospital between 01/08/2003 and 31/12/2010 were prospectively followed for VAP development according to the National Healthcare Safety Network criteria. The patients were categorized into four groups: EO if VAP occurred within 4 days of intubation and hospital admission; LO if VAP occurred after 4 days of admission; EL if VAP occurred within 4 days of intubation, but after the fourth hospitalization day; and LL if VAP occurred after the fourth day of intubation and hospitalization. Out of the 394 VAP episodes, 63 (16%) were EO episodes, 331 (84.0%) were LO episodes, 40 (10.1%) were EL episodes and 291 (73.1%) were LL episodes. The isolated microorganisms were comparable among the four groups, with a similar rate of potentially multidrug resistant organisms in the EO-VAP (31.7%), LO-VAP (40.8%), EL-VAP (37.5%) and LL-VAP (43.3%) samples. The hospital mortality was 24% for EO-VAP cases, 28% for LO-VAP cases, 40% for EL-VAP cases and 49% for LL-VAP cases. However, in the adjusted multivariate analysis, neither LO-VAP, EL-VAP nor LL-VAP was associated with an increased risk of hospital mortality compared with EO-VAP (OR, 0.86 95% CI, 0.34-2.19; 1.22; 95% CI, 0.41-3.68, and 0.95; 95% CI, 0.43-2.10, respectively). In this study, the occurrence of potential multidrug resistant pathogens and the mortality risk were similar regardless of VAP timing from hospital admission and intubation. The bacterial isolates obtained from the VAP cases did not follow an early vs. late-onset pattern, and thus, these terms may not be clinically helpful.

Short Operative Duration and Surgical Site Infection Risk in Hip and Knee Arthroplasty Procedures.

To determine the association (1) between shorter operative duration and surgical site infection (SSI) and (2) between surgeon median operative duration and SSI risk among first-time hip and knee arthroplasties. Retrospective cohort study A total of 43 community hospitals located in the southeastern United States. Adults who developed SSIs according to National Healthcare Safety Network criteria within 365 days of first-time knee or hip arthroplasties performed between January 1, 2008 and December 31, 2012. Log-binomial regression models estimated the association (1) between operative duration and SSI outcome and (2) between surgeon median operative duration and SSI outcome. Hip and knee arthroplasties were evaluated in separate models. Each model was adjusted for American Society of Anesthesiology score and patient age. A total of 25,531 hip arthroplasties and 42,187 knee arthroplasties were included in the study. The risk of SSI in knee arthroplasties with an operative duration shorter than the 25th percentile was 0.40 times the risk of SSI in knee arthroplasties with an operative duration between the 25th and 75th percentile (risk ratio [RR], 0.40; 95% confidence interval [CI], 0.38-0.56; P<.01). Short operative duration did not demonstrate significant association with SSI for hip arthroplasties (RR, 1.04; 95% CI, 0.79-1.37; P=.36). Knee arthroplasty surgeons with shorter median operative durations had a lower risk of SSI than surgeons with typical median operative durations (RR, 0.52; 95% CI, 0.43-0.64; P<.01). Short operative durations were not associated with a higher SSI risk for knee or hip arthroplasty procedures in our analysis.

Epidemiology, associated factors and outcomes of ICU-acquired infections caused by Gram-negative bacteria in critically ill patients: an observational, retrospective study.

BackgroundGram-negative bacteria are increasingly responsible for nosocomial infections, including ICU-acquired infections. Due to high virulence, rate of multi-drug resistance and limited availability of new agents, these infections create cumbersome clinical burdens, making it important to reduce the risk of their occurrence. The aim of the study was to assess epidemiology-related factors and outcomes of Gram-negative, ICU-acquired infections in a cohort of medical-surgical patients.MethodsA retrospective survey was conducted on all patients admitted to a mixed ICU from January 2012 to December 2013. ‘ICU-acquired infections’ were defined as new infections acquired no less than 48 h after ICU admission. Diagnosis was made according to the Centers for Disease Control and Prevention National Healthcare Safety Network (CDC/NHSN) criteria. Differences across patients who did and did not acquire a Gram-negative infection were tested regarding age, sex, body mass index, medical or surgical admission, cardiovascular comorbidities, chronic obstructive pulmonary disease, diabetes, end-stage renal failure, co-existing tumours and prophylactic anti-fungal treatment. Multivariate analysis was used to assess the independency of these associations. Finally, differences in ICU-mortality, ICU-length of stay and duration of mechanical ventilation were tested across patients with and without new, ICU-acquired, Gram-negative infections.ResultsOf 494 patients admitted to the ICU, 46 (9.3 %) acquired an infection 48 or more hours after admittance. In 30/46 patients (65.2 %) the isolated bacterium was Gram-negative. Univariate analysis showed that clinical factors associated with new ICU-acquired Gram-negative infections were medical admission (p < 0.001, 95 % CI 0.59 – 0.29, OR = 0.13), chronic kidney disease (p = 0.018, 95 % CI 1.20 – 7.34, OR = 2.98) and prophylactic antifungal therapy (p < 0.001, 95 % CI 1.91 – 9.79, OR = 4.33). At multivariate analysis, only medical admission and prophylactic antifungal therapy were significantly associated with ICU-acquired Gram-negative infections. Higher ICU-length of stay and longer duration of mechanical ventilation were associated with these infections while ICU-mortality did not significantly differ.ConclusionsICU-acquired Gram-negative infections were common in a cohort of mixed medical-surgical patients. Only medical admission and anti-fungal prophylaxis were found to be independently associated with these infections; they were not found to have a significant effect on ICU-mortality.

Surgical Site Infection following Cesarean Delivery: Patient, Provider, and Procedure-Specific Risk Factors.

This study aims to identify risk factors for cesarean delivery (CD) surgical site infection (SSI). study design: Retrospective analysis of 2,739 CDs performed at the University of Pittsburgh in 2011. CD SSIs were defined using National Healthcare Safety Network (NHSN) criteria. Chi-square test and t-test were used for bivariate analyses and multivariate logistic regression was used to identify SSI risk factors. Of 2,739 CDs, 178 (6.5%) were complicated by SSI. Patients with a SSI were more likely to have Medicaid, have resident physicians perform the CD, an American Society of Anesthesiologists (ASA) class of ≥ 3, chorioamnionitis, tobacco use, and labor before CD. In multivariable analysis, labor (odds ratio [OR], 2.35; 95% confidence interval [95% CI], 1.65-3.38), chorioamnionitis (OR, 2.24; 95% CI, 1.25-3.83), resident teaching service (OR, 2.15; 95% CI, 1.54-3.00), tobacco use (OR, 1.70; 95% CI, 1.04-2.70), ASA class ≥ 3 (OR, 1.61; 95% CI, 1.06-2.39), and CDs performed for nonreassuring fetal status (OR, 0.43; 95% CI, 0.26-0.67) were significantly associated with CD SSI. Multiple patient, provider, and procedure-specific risk factors contribute to CD SSI risk which may be targeted in infection-control efforts.

Postoperative infection in spine surgery: does the month matter?

The relationship between time of year and surgical site infection (SSI) following neurosurgical procedures is poorly understood. Authors of previous reports have demonstrated that rates of SSI following neurosurgical procedures performed during the summer months were higher compared with rates during other seasons. It is unclear, however, if this difference was related to climatological changes or inexperienced medical trainees (the July effect). The aim of this study was to evaluate for seasonal variation of SSI following spine surgery in a network of nonteaching community hospitals. The authors analyzed 6 years of prospectively collected surveillance data (January 1, 2007, to December 31, 2012) from all laminectomies and spinal fusions from 20 hospitals in the Duke Infection Control Outreach Network of community hospitals. Surgical site infections were defined using National Healthcare Safety Network criteria and identified using standardized methods across study hospitals. Regression models were then constructed using Poisson distribution to evaluate for seasonal trends by month. Each analysis was first performed for all SSIs and then for SSIs caused by specific organisms or classes of organisms. Categorical analysis was performed using two separate definitions of summer: June through September (definition 1), and July through September (definition 2). The prevalence rate of SSIs during the summer was compared with the prevalence rate during the remainder of the year by calculating prevalence rate ratios and 95% confidence intervals. The authors identified 642 SSIs following 57,559 neurosurgical procedures (overall prevalence rate = 1.11/100 procedures); 215 occurred following 24,466 laminectomies (prevalence rate = 0.88/100 procedures), and 427 following 33,093 spinal fusions (prevalence rate = 1.29/100 procedures). Common causes of SSI were Staphylococcus aureus (n = 380; 59%), coagulase-negative staphylococci (n = 90; 14%), and Escherichia coli (n = 41; 6.4%). Poisson regression models demonstrated increases in the rates of SSI during each of the summer months for all SSIs and SSIs due to gram-positive cocci, S. aureus, and methicillin-sensitive S. aureus. Categorical analysis confirmed that the rate of SSI during the 4-month summer period was higher than the rate during the remainder of the year, regardless of which definition for summer was used (definition 1, p = 0.008; definition 2, p = 0.003). Similarly, the rates of SSI due to grampositive cocci and S. aureus were higher during the summer months than the remainder of the year regardless of which definition of summer was used. However, the rate of SSI due to gram-negative bacilli was not. The rate of SSI following fusion or spinal laminectomy/laminoplasty was higher during the summer in this network of community hospitals. The increase appears to be related to increases in SSIs caused by gram-positive cocci and, more specifically, S. aureus. Given the nonteaching nature of these hospitals, the findings demonstrate that increases in the rate of SSI during the summer are more likely related to ecological and/or environmental factors than the July effect.