Macrolides are associated with a better survival rate in patients hospitalized with community-acquired but not healthcare-associated pneumonia.

BACKGROUND: Macrolide-based treatment has been associated with survival benefit in patients hospitalized with community-acquired pneumonia (CAP). However, the influence of macrolide therapy in all patients hospitalized with pneumonia, including healthcare-associated pneumonia (HCAP), is unclear. METHODS: Analysis of a retrospective single-center cohort. RESULTS: Community-acquired pneumonia was present in 220 (22.5%) of all patients with pneumonia admitted through the emergency department of Barnes-Jewish Hospital, and HCAP was present in 757. Macrolide-based treatment was administered to 411 patients (42.1%). These patients were more likely to have CAP than were patients not receiving macrolide-based therapy (35.3% vs. 13.3%; p<0.001) and had lower scores on the CURB-65 tool, a measure of the severity of illness (2.4±1.5 vs. 3.1±1.3; p<0.001). Patients receiving macrolides also had a lower hospital mortality rate in univariable analysis (12.7% vs. 27.2%; p<0.001). A propensity score analysis showed that macrolide-based treatment was associated with a lower in-hospital mortality rate (adjusted odds ratio [AOR] 0.67; 95% confidence interval [CI] 0.54-0.81; p=0.043). Separate propensity score analyses of patients with CAP (AOR 0.20; 95% CI 0.11-0.34; p=0.003) and HCAP (AOR 0.81; 95% CI 0.65-1.01; p=0.337) produced discordant findings. CONCLUSIONS: Macrolide-based treatment was associated with better survival in patients hospitalized with pneumonia. The survival advantage appeared predominantly among patients with CAP.

Readmission following hospitalization for pneumonia: the impact of pneumonia type and its implication for hospitals.

BACKGROUND: Readmission rates following discharge after pneumonia are thought to represent the quality of care. Factors associated with readmission, however, remain poorly described. It is unclear if readmission rates vary based on pneumonia type. METHODS: We retrospectively identified adults admitted to an index hospital with non-nosocomial pneumonia (January through December 2010) and who survived to discharge. We only included patients with bacterial evidence of infection. Readmission in the 30 days following discharge to any of 9 hospitals comprising the index hospital's healthcare system served as the primary end point. We recorded demographics, severity of illness, comorbidities, and infection-related factors. We noted whether the patient had healthcare-associated pneumonia (HCAP) versus community-acquired pneumonia. We utilized logistic regression analysis to determine factors independently associated with readmission. RESULTS: The cohort included 977 subjects; 78.9% survived to discharge. The readmission rate equaled 20%. Neither disease severity nor the rate of initially inappropriate antibiotic therapy correlated with readmission. Subjects with HCAP were 7.5 (95% confidence interval [CI], 3.6-15.7) times more likely to be readmitted. Four HCAP criteria were independently associated with readmission: admission from long-term care (adjusted odds ratio [AOR], 2.2 [95% CI, 1.4-3.4]); immunosuppression (AOR, 1.9 [95% CI, 1.3-2.9]); prior antibiotics (AOR, 1.7 [95% CI, 1.2-2.6]); and prior hospitalization (AOR, 1.7 [95% CI, 1.1-2.5]). CONCLUSIONS: Readmission for pneumonia is common but varies based on pneumonia type. The variables associated with readmission do not reflect factors that hospitals directly control. Use of one rule to guide payment that fails to account for HCAP and the HCAP criteria on readmission seems inappropriate.

Prolonged infusion antibiotics for suspected gram-negative infections in the ICU: a before-after study.

BACKGROUND: ß-Lactam antibiotics demonstrate time-dependent killing. Prolonged infusion of these agents is commonly performed to optimize the time the unbound concentration of an antibiotic remains greater than the minimum inhibitory concentration and decrease costs, despite limited evidence suggesting improved clinical results. OBJECTIVE: To determine whether prolonged infusion of ß-lactam antibiotics improves outcomes in critically ill patients with suspected gram-negative infection. METHODS: We conducted a single-center, before-after, comparative effectiveness trial between January 2010 and January 2011 in the intensive care units at Barnes-Jewish Hospital, an urban teaching hospital affiliated with the Washington University School of Medicine in St. Louis, MO. Outcomes were compared between patients who received standardized dosing of meropenem, piperacillin-tazobactam, or cefepime as an intermittent infusion over 30 minutes (January 1, 2010, to June 30, 2010) and patients who received prolonged infusion over 3 hours (August 1, 2010, to January 31, 2011). RESULTS: A total of 503 patients (intermittent infusion, n = 242; prolonged infusion, n = 261) treated for gram-negative infection were included in the clinically evaluable population. Approximately 50% of patients in each group received cefepime and 20% received piperacillin-tazobactam. More patients in the intermittent infusion group received meropenem (35.5% vs 24.5%; p = 0.007). Baseline characteristics were similar between groups, with the exception of a greater occurrence of chronic obstructive pulmonary disease (COPD) in the intermittent infusion group. Treatment success rates in the clinically evaluable group were 56.6% for intermittent infusion and 51.0% for prolonged infusion (p = 0.204), and in the microbiologically evaluable population, 55.2% for intermittent infusion and 49.5% for prolonged infusion (p = 0.486). Fourteen-day, 30-day, and inhospital mortality rates in the clinically evaluable population for the intermittent and prolonged infusion groups were 13.2% versus 18.0% (p = 0.141), 23.6% versus 25.7% (p = 0.582), and 19.4% versus 23.0% (p = 0.329). CONCLUSIONS: Routine use of prolonged infusion of time-dependent antibiotics for the empiric treatment of gram-negative bacterial infections offers no advantage over intermittent infusion antibiotic therapy with regard to treatment success, mortality, or hospital length of stay. These results were confirmed after controlling for potential confounders in a multivariate analysis.

The determinants of hospital mortality among patients with septic shock receiving appropriate initial antibiotic treatment*.

OBJECTIVE: To identify the determinants of hospital mortality among patients with septic shock receiving appropriate initial antibiotic treatment. DESIGN: A retrospective cohort study of hospitalized patients with blood culture positive septic shock (January 2002-December 2007). SETTING: Barnes-Jewish Hospital, a 1,250-bed urban teaching hospital. PATIENTS: Four hundred thirty-six consecutive patients with septic shock and a positive blood culture. INTERVENTIONS: Data abstraction from computerized medical records. MEASUREMENTS AND MAIN RESULTS: Septic shock was associated with bloodstream infection due to Gram-negative bacteria (59.2%) and Gram-positive bacteria (40.8%). Two hundred twenty-four patients (51.4%) died during their hospitalization. The presence of infection attributed to antibiotic-resistant bacteria was similar for patients who survived and expired (22.6% vs. 20.1%; p = .516). Multivariate logistic regression analysis demonstrated that infection acquired in the intensive care unit (adjusted odds ratio 1.99; 95% confidence interval 1.52-2.60; p = .011) and increasing Acute Physiology and Chronic Health Evaluation II scores (one-point increments) (adjusted odds ratio 1.11; 95% confidence interval 1.09-1.14; p < .001) were independently associated with a greater risk of hospital mortality, whereas infection with methicillin-susceptible Staphylococcus aureus (adjusted odds ratio 0.32; 95% confidence interval 0.20-0.52; p = .017) was independently associated with a lower risk of hospital mortality. Patients infected with methicillin-susceptible Staphylococcus aureus infections were statistically younger and had lower Charlson comorbidity and Acute Physiology and Chronic Health Evaluation II scores compared to patients with non-methicillin-susceptible Staphylococcus aureus infections. CONCLUSIONS: Among patients with septic shock who receive appropriate initial antibiotic treatment, acquisition of infection in the intensive care unit and severity of illness appear to be the most important determinants of clinical outcome.

An institutional perspective on the impact of recent antibiotic exposure on length of stay and hospital costs for patients with gram-negative sepsis.

BACKGROUND: Prior antibiotic exposure has been associated with the emergence of antibiotic resistance in subsequent bacterial infections, whose outcomes are typically worse than similar infections with more antibiotic susceptible infections. The influence of prior antibiotic exposure on hospital length of stay (LOS) and costs in patients with severe sepsis or septic shock attributed to Gram-negative bacteremia has not been previously examined. METHODS: A retrospective cohort study of hospitalized patients (January 2002-December 2007) was performed at Barnes-Jewish Hospital, a 1200-bed urban teaching hospital. Patients with Gram-negative bacteremia complicated by severe sepsis or septic shock had data abstraction from computerized medical records. We examined a consecutive cohort of 754 subjects (mean age 59.3 ± 16.3 yrs, mean APACHE II 23.7 ± 6.7). RESULTS: Escherichia coli (30.8%), Klebsiella pneumoniae (23.2%), and Pseudomonas aeruginosa (17.6%) were the most common organisms isolated from blood cultures. 310 patients (41.1%) had exposure to antimicrobial agents in the previous 90 days. Patients with recent antibiotic exposure had greater inappropriate initial antimicrobial therapy (45.4% v. 21.2%; p < 0.001) and hospital mortality (51.3% v. 34.0%; p < 0.001) compared to patients without recent antibiotic exposure. The unadjusted median LOS (25th percentile, 75th percentile) following sepsis onset in patients with prior antimicrobial exposure was 13.0 days (5.0 days, 24.0 days) compared to 8.0 days (5.0 days, 14.0 days) in those without prior antimicrobial exposure (p < 0.001). In a Cox model controlling for multiple confounders, prior antibiotic exposure independently correlated with remaining hospitalized (Adjusted hazard ratio: 1.473, 95% CI: 1.297-1.672, p < 0.001). Adjusting for potential confounders indicated that prior antibiotic exposure independently increased median attributable LOS by 5.0 days. Similarly, total hospital costs following sepsis onset was significantly greater among patients with prior antimicrobial exposure (median values: $94,737 v. $21,329; p < 0.001). CONCLUSIONS: Recent antibiotic exposure is associated with increased LOS and hospital costs in Gram-negative bacteremia complicated by severe sepsis or septic shock. Clinicians and hospital administrators should consider the potential impact of recent antibiotic exposure when formulating empiric treatment decisions for patients with serious infections attributed to Gram-negative bacteria.

Validation of a clinical score for assessing the risk of resistant pathogens in patients with pneumonia presenting to the emergency department.

BACKGROUND: Resistant organisms (ROs) are increasingly implicated in pneumonia in patients presenting to the emergency department (ED). The concept of healthcare-associated pneumonia (HCAP) exists to help identify patients infected with ROs but may be overly broad. We sought to validate a previously developed score for determining the risk for an RO and to compare it with the HCAP definition. METHODS: We evaluated adult patients admitted via the ED with bacterial pneumonia (January-December 2010). We defined methicillin-resistant Staphylococcus aureus (MRSA), Pseudomonas aeruginosa, and extended-spectrum ß-lactamases as ROs. The risk score was as follows: 4, recent hospitalization; 3, nursing home; 2, chronic hemodialysis; 1, critically ill. We evaluated the screening value of the score and of HCAP by determining their areas under the receiver-operating characteristic (AUROC) curves for predicting ROs. RESULTS: The cohort included 977 patients, and ROs were isolated in 46.7%. The most common organisms included MRSA (22.7%), P. aeruginosa (19.1%), and Streptococcus pneumoniae (19.1%). The risk score was higher in those with an RO (median score, 4 vs 1; P < .001). The AUROC for HCAP equaled 0.62 (95% confidence interval [CI], .58-.65) versus 0.71 (95% CI, .66-.73) for the risk score. As a screening test for ROs, a score > 0 had a high negative predictive value (84.5%) and could lead to fewer patients unnecessarily receiving broad-spectrum antibiotics. CONCLUSIONS: ROs are common in patients presenting to the ED with pneumonia. A simple clinical risk score performs moderately well at classifying patients regarding their risk for an RO.

Health care-associated pneumonia (HCAP): empiric antibiotics targeting methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa predict optimal outcome.

Inappropriate initial antimicrobial therapy (IIAT) has been associated with decreased survival in patients with health care-associated pneumonia (HCAP). We performed a study to determine whether empiric HCAP antibiotic regimens targeting methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa are associated with greater appropriate therapy. A retrospective cohort study of culture-positive HCAP over 6 years (January 2003-December 2008) was performed at Barnes-Jewish Hospital, a 1200-bed urban teaching hospital. We identified 757 consecutive patients with HCAP. IIAT was administered to 213 (28%) patients. The pathogens most frequently associated with IIAT included P. aeruginosa (n=60, 28%), MRSA (n=58, 27%), and Acinetobacter species (n=32, 15%).Multivariate logistic regression analysis demonstrated that empiric anti-pseudomonal antibiotics (adjusted odds ratio [AOR], 1.75; 95% confidence interval [CI], 1.34-2.29; p=0.036), empiric anti-MRSA antibiotics (AOR, 1.71; 95% CI, 1.36-2.14; p=0.018), infection with Streptococcus pneumoniae (AOR, 2.82; 95% CI, 2.03-3.91; p=0.002), absence of Acinetobacter species infection (AOR, 10.57; 95% CI, 7.29-15.33; p<0.001), absence of P. aeruginosa infection (AOR, 1.69; 95% CI, 1.36-2.05; p=0.014), and absence of Stenotrophomonas maltophilia infection (AOR, 20.43; 95% CI, 9.35-44.66; p<0.001) are independent predictors of appropriate therapy for HCAP. Our study suggests that initial therapy for HCAP should include antibiotics targeting MRSA and P. aeruginosa in order to provide appropriate initial therapy. However, the selection of individual antibiotic agents should be based on local patterns of infection and adjusted when microbiology results become available.

Resistance to empiric antimicrobial treatment predicts outcome in severe sepsis associated with Gram-negative bacteremia.

BACKGROUND: Gram-negative bacteria are an important cause of severe sepsis. Recent studies have demonstrated reduced susceptibility of Gram-negative bacteria to currently available antimicrobial agents. METHODS: We performed a retrospective cohort study of patients with severe sepsis who were bacteremic with Pseudomonas aeruginosa, Acinetobacter species, or Enterobacteriaceae from 2002 to 2007. Patients were identified by the hospital informatics database and pertinent clinical data (demographics, baseline severity of illness, source of bacteremia, and therapy) were retrieved from electronic medical records. All patients were treated with antimicrobial agents within 12 hours of having blood cultures drawn that were subsequently positive for bacterial pathogens. The primary outcome was hospital mortality. RESULTS: A total of 535 patients with severe sepsis and Gram-negative bacteremia were identified. Hospital mortality was 43.6%, and 82 (15.3%) patients were treated with an antimicrobial regimen to which the causative pathogen was resistant. Patients infected with a resistant pathogen had significantly greater risk of hospital mortality (63.4% vs 40.0%; P < 0.001). In a multivariate analysis, infection with a pathogen that was resistant to the empiric antibiotic regimen, increasing APACHE II scores, infection with Pseudomonas aeruginosa, healthcare-associated hospital-onset infection, mechanical ventilation, and use of vasopressors were independently associated with hospital mortality. CONCLUSIONS: In severe sepsis attributed to Gram-negative bacteremia, initial treatment with an antibiotic regimen to which the causative pathogen is resistant was associated with increased hospital mortality. This finding suggests that rapid determination of bacterial susceptibility could influence treatment choices in patients with severe sepsis potentially improving their clinical outcomes.

Evaluation of therapeutic anticoagulation with enoxaparin and associated anti-Xa monitoring in patients with morbid obesity: a case series.

Our purpose was to describe anti-Xa levels, dosage requirements, and complications associated with enoxaparin treatment doses in patients with morbid obesity. Inpatients with a BMI >40 kg/m(2) at an academic medical center prescribed therapeutic enoxaparin from 2004 to 2010 who also had an associated anti-Xa level were included in this retrospective evaluation. Twenty-six patients were identified having median weight of 162 kg (range 106-243), median BMI of 49.5 kg/m(2) (range 40.1-98.1), and median enoxaparin duration of 4 days (range 1-32). Venous thromboembolism was the most common reason for anticoagulation (n = 19, 73%). The median starting dose was 0.8 mg/kg actual body weight (range 0.51-1; absolute dose 80-150 mg) every 12 h. Twelve patients (46%) achieved a goal anti-Xa level, 10 (38%) were above goal and 4 (15%) were uninterpretable. Among the 10 patients with anti-Xa levels above goal, the median initial dose was 0.85 mg/kg (range 0.75-1) versus 0.74 mg/kg (range 0.51-1) for patients at goal with similar median peak serum creatinine (PSCr) values between these two groups (P > 0.05). No bleeding events occurred in patients achieving goal anticoagulation versus 4/10 (40%) with high anti-Xa levels (P = 0.033) with similar median PSCr between these groups. No thrombotic events occurred while on therapy. The majority in this cohort with morbid obesity achieved anti-Xa levels at or above goal at doses less than the recommended 1 mg/kg every 12 h. Bleeding events were more frequent among patients with anti-Xa levels above goal, despite similar PSCr values.

Impact of previous antibiotic therapy on outcome of Gram-negative severe sepsis.

OBJECTIVE: To determine whether exposure to antimicrobial agents in the previous 90 days resulted in decreased bacterial susceptibility and increased hospital mortality in patients with severe sepsis or septic shock attributed to Gram-negative bacteremia. DESIGN: A retrospective cohort study of hospitalized patients (January 2002 to December 2007). SETTING: Barnes-Jewish Hospital, a 1200-bed urban teaching hospital. PATIENTS: Seven hundred fifty-four consecutive patients with Gram-negative bacteremia complicated by severe sepsis or septic shock. INTERVENTIONS: Data abstraction from computerized medical records. MEASUREMENTS AND MAIN RESULTS: Escherichia coli (30.8%), Klebsiella pneumoniae (23.2%), and Pseudomonas aeruginosa (17.6%) were the most common isolates from blood cultures. Three hundred ten patients (41.1%) had recent antibiotic exposure. Cefepime was the most common agent with previous exposure (50.0%) followed by ciprofloxacin (32.6%) and imipenem or meropenem (28.7%). Patients with prior antibiotic exposure had significantly higher rates of resistance to cefepime (29.0% vs. 7.0%), piperacillin/tazobactam (31.9% vs. 11.5%), carbapenems (20.0% vs. 2.5%), ciprofloxacin (39.7% vs. 17.6%), and gentamicin (26.1% vs. 7.9%) (p < .001 for all comparisons). Patients with recent antibiotic exposure had greater inappropriate initial antimicrobial therapy (45.4% vs. 21.2%; p < .001) and hospital mortality (51.3% vs. 34.0%; p < .001) compared with patients without recent antibiotic exposure. Multivariate logistic regression analysis demonstrated that recent antibiotic exposure was independently associated with hospital mortality (adjusted odds ratio, 1.70; 95% confidence interval, 1.41-2.06; p = .005). Other variables independently associated with hospital mortality included use of vasopressors, infection resulting from P. aeruginosa, inappropriate initial antimicrobial therapy, increasing Acute Physiology and Chronic Health Evaluation II scores, and the number of acquired organ failures. CONCLUSIONS: Recent antibiotic exposure is associated with increased hospital mortality in Gram-negative bacteremia complicated by severe sepsis or septic shock. Clinicians caring for patients with severe sepsis or septic shock should consider recent antibiotic exposure when formulating empiric antimicrobial regimens for suspected Gram-negative bacterial infection.

Inappropriate antibiotic therapy in Gram-negative sepsis increases hospital length of stay.

OBJECTIVES: To describe the impact of initially inappropriate antibiotic therapy on hospital length of stay in Gram-negative severe sepsis and septic shock. DESIGN: Retrospective cohort. SETTING: Academic urban hospital. PATIENTS: Patients with Gram-negative bacteremia (primary or secondary, nosocomial or non-nosocomial) and severe sepsis or septic shock. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We defined initially inappropriate antibiotic therapy as occurring when the patient either was not administered an antibiotic within 24 hrs of sepsis onset or was treated with an antibiotic to which the culprit pathogen was resistant in vitro. The cohort included 760 subjects (mean age 59.3 ± 16.3 yrs, mean Acute Physiology and Chronic Health Evaluation II score 23.7 ± 6.7). More than half of infections were nosocomial (55.1%), and Escherichia coli represented the most common pathogen (n = 225). Pseudomonas species were isolated in 17.4% of patients. Nearly one-third of patients (31.3%) received initially inappropriate antibiotic therapy. Patients administered initially inappropriate antibiotic therapy were more likely to have a nosocomial infection, to have underlying cancer or diabetes or both, to require chronic hemodialysis, and to undergo mechanical ventilation. Those administered initially inappropriate antibiotic therapy also faced higher inhospital mortality. The unadjusted median length of stay after sepsis onset in those administered initially inappropriate antibiotic therapy was 11 days compared to 9 days in those treated appropriately (p = .028 by log-rank test). In a Cox model controlling for the multiple confounders noted, initially inappropriate antibiotic therapy independently correlated with continued hospitalization (adjusted hazard ratio 1.19, 95% confidence interval 1.01-1.40, p = .044). Adjusting for these covariates indicated that initially inappropriate antibiotic therapy independently increased the median attributable length of stay by 2 days. CONCLUSIONS: Initially inappropriate antibiotic therapy occurs in one-third of persons with severe sepsis and septic shock attributable to Gram-negative organisms. Beyond its impact on mortality, initially inappropriate antibiotic therapy is significantly associated with length of stay in this population. Efforts to decrease rates of initially inappropriate antibiotic therapy may serve to improve hospital resource use by leading to shorter overall hospital stays.

Implementation of a real-time computerized sepsis alert in nonintensive care unit patients.

OBJECTIVE: Early therapy of sepsis involving fluid resuscitation and antibiotic administration has been shown to improve patient outcomes. A proactive tool to identify patients at risk for developing sepsis may decrease time to interventions and improve patient outcomes. The objective of this study was to evaluate whether the implementation of an automated sepsis screening and alert system facilitated early appropriate interventions. DESIGN: Prospective, observational, pilot study. SETTING: Six medicine wards in Barnes-Jewish Hospital, a 1250-bed academic medical center. PATIENTS: Patients identified by the sepsis screen while admitted to a medicine ward were included in the study. A total of 300 consecutive patients were identified comprising the nonintervention group (n=200) and the intervention group (n=100). INTERVENTIONS: A real-time sepsis alert was implemented for the intervention group, which notified the charge nurse on the patient's hospital ward by text page. MEASUREMENTS AND MAIN RESULTS: Within 12 hrs of the sepsis alert, interventions by the treating physicians were assessed, including new or escalated antibiotics, intravenous fluid administration, oxygen therapy, vasopressors, and diagnostic tests. After exclusion of patients without commitment to aggressive management, 181 patients in the nonintervention group and 89 patients in the intervention group were analyzed. Within 12 hrs of the sepsis alert, 70.8% of patients in the intervention group had received≥1 intervention vs. 55.8% in the nonintervention group (p=.018). Antibiotic escalation, intravenous fluid administration, oxygen therapy, and diagnostic tests were all increased in the intervention group. This was a single-center, institution- and patient-specific algorithm. CONCLUSIONS: The sepsis alert developed at Barnes-Jewish Hospital was shown to increase early therapeutic and diagnostic interventions among nonintensive care unit patients at risk for sepsis.

Methicillin-resistant Staphylococcus aureus nasal colonization is a poor predictor of intensive care unit-acquired methicillin-resistant Staphylococcus aureus infections requiring antibiotic treatment.

OBJECTIVE: To test whether intensive care unit (ICU) nasal screening for methicillin-resistant Staphylococcus aureus (MRSA) predicts the presence or absence of MRSA infections requiring antimicrobial treatment. DESIGN: A prospective cohort study. SETTING: Medical ICU at Barnes-Jewish Hospital, a 1252-bed urban teaching hospital. PATIENTS: Seven hundred forty-nine consecutive patients admitted to the medical ICU over a 7-mo period (November 2007 through June 2008). INTERVENTIONS: Nasal swabs were obtained at ICU admission and weekly thereafter for MRSA detection by using polymerase chain reaction. All subjects were followed for the development of MRSA infection during their ICU stay. MEASUREMENTS AND MAIN RESULTS: One hundred sixty-four (21.9%) patients had positive nasal colonization with MRSA at the time of ICU admission. The predictive accuracy of MRSA nasal colonization for ICU-acquired MRSA infections, either lower respiratory tract infection or bloodstream infection, was poor (lower respiratory tract infection: sensitivity, 24.2%; specificity, 78.5%; positive predictive value, 17.7%; and negative predictive value, 84.4%; and bloodstream infection: sensitivity, 23.1%; specificity, 78.2%; positive predictive value, 11.0%; and negative predictive value, 89.7%). Addition of nasal-colonization results obtained during the ICU stay did not appreciably change the predictive accuracy of this test for identification of subsequent lower respiratory tract infections and bloodstream infections attributed to MRSA requiring antimicrobial treatment. CONCLUSIONS: In this analysis, nasal colonization with MRSA was found to be a poor predictor for the subsequent occurrence of MRSA lower respiratory tract infections and MRSA bloodstream infections requiring antimicrobial treatment. Clinicians should be cautious in using the results of nasal-colonization testing to determine the need for MRSA treatment among patients with ICU-acquired infections.

Clinical, microbiologic, and genetic determinants of persistent methicillin-resistant Staphylococcus aureus bacteremia.

Methicillin-resistant Staphylococcus aureus bacteremia (MRSAB) often persists despite full susceptibility to vancomycin; therefore, associated factors were assessed. A retrospective cohort analysis of 222 patients with MRSAB treated with vancomycin was conducted; patients with persistent MRSAB (pMRSAB) were compared to those with nonpersistent bacteremia (NPB). Incidence of pMRSAB was 9%. More patients with vancomycin MIC = 2 mg/L had pMRSAB (16%) compared to patients with vancomycin MIC <2 mg/L (5%), P = 0.012. SCCmec type and Panton-Valentine leukocidin production were similar between patients with pMRSAB and NPB. There was no difference in vancomycin troughs, time to first dose, or area under the concentration-time curve/MIC between groups. More metastatic complications were observed in pMRSAB 63% versus NPB 32% (P = 0.005). Multivariate analysis found endocarditis (odds ratio [OR], 2.3; P = 0.021), complicated MRSAB (OR, 2.6; P = 0.009), vancomycin MIC = 2 (OR, 2.6; P = 0.009), and septic shock (OR 2.2 P = 0.031), which were independent predictors of pMRSAB.

Use of cytomegalovirus intravenous immune globulin for the adjunctive treatment of cytomegalovirus in hematopoietic stem cell transplant recipients.

STUDY OBJECTIVE: To describe the characteristics and clinical outcomes of hematopoietic stem cell transplant (HSCT) recipients who received adjunctive cytomegalovirus intravenous immune globulin (CMV-IVIG) for probable or proven CMV disease. DESIGN: Retrospective cohort study. SETTING: Large, university-affiliated, tertiary-care medical center. PATIENTS: Thirty-five adult HSCT recipients who received at least one dose of CMV-IVIG for adjunctive treatment of probable or proven CMV disease between January 1, 1999, and December 31, 2007. MEASUREMENTS AND MAIN RESULTS: All-cause mortality at hospital discharge was the primary outcome. All patients received an allogeneic HSCT. Twenty-six patients (74%) had pneumonitis, nine (26%) had enteritis, and 29 (83%) had CMV viremia. All patients received concomitant antiviral therapy; 31 (89%) received ganciclovir, and 14 (40%) received foscarnet. All-cause mortality at hospital discharge was 49% (17 patients). Patient characteristics associated with mortality included requiring intubation for CMV pneumonia (11 [79%] of 14 nonsurvivors vs 3 (25%) of 12 survivors, p=0.016) and earlier disease onset after HSCT (median 48 days for nonsurvivors vs 106 days for survivors, p<0.001). In the multivariate analysis, only requiring intubation for CMV pneumonia remained a significant risk factor for increased mortality. A low rate of adverse events was attributed to CMV-IVIG, with mild hypertension (two patients [6%]) and erythema and chills (one patient [3%]) being the most common. CONCLUSION: The mortality rate in our study population was similar to previous reports in the literature and may be somewhat lower than rates reported with antiviral monotherapy. Our analysis suggests that factors associated with mortality include the need for intubation and, possibly, earlier onset of CMV disease after HSCT. Treatment with CMV-IVIG appears to be well tolerated in HSCT recipients. These findings support further trials of CMV-IVIG efficacy in this setting.

Empiric combination antibiotic therapy is associated with improved outcome against sepsis due to Gram-negative bacteria: a retrospective analysis.

The optimal approach for empirical antibiotic therapy in patients with severe sepsis and septic shock remains controversial. A retrospective cohort study was conducted in the intensive care units of a university hospital. The data from 760 patients with severe sepsis or septic shock associated with Gram-negative bacteremia was analyzed. Among this cohort, 238 (31.3%) patients received inappropriate initial antimicrobial therapy (IIAT). The hospital mortality rate was statistically greater among patients receiving IIAT compared to those initially treated with an appropriate antibiotic regimen (51.7% versus 36.4%; P < 0.001). Patients treated with an empirical combination antibiotic regimen directed against Gram-negative bacteria (i.e., beta-lactam plus aminoglycoside or fluoroquinolone) were less likely to receive IIAT compared to monotherapy (22.2% versus 36.0%; P < 0.001). The addition of an aminoglycoside to a carbapenem would have increased appropriate initial therapy from 89.7 to 94.2%. Similarly, the addition of an aminoglycoside would have increased the appropriate initial therapy for cefepime (83.4 to 89.9%) and piperacillin-tazobactam (79.6 to 91.4%). Logistic regression analysis identified IIAT (adjusted odds ratio [AOR], 2.30; 95% confidence interval [CI] = 1.89 to 2.80) and increasing Apache II scores (1-point increments) (AOR, 1.11; 95% CI = 1.09 to 1.13) as independent predictors for hospital mortality. In conclusion, combination empirical antimicrobial therapy directed against Gram-negative bacteria was associated with greater initial appropriate therapy compared to monotherapy in patients with severe sepsis and septic shock. Our experience suggests that aminoglycosides offer broader coverage than fluoroquinolones as combination agents for patients with this serious infection.

A comparison of culture-positive and culture-negative health-care-associated pneumonia.

OBJECTIVE: The aim of this study is to describe the initial antibiotic treatment regimens, severity of illness, and in-hospital mortality among culture-negative (CN) and culture-positive (CP) patients with health-care-associated pneumonia (HCAP). METHODS: We used a retrospective cohort study, examining adult patients with HCAP from Barnes-Jewish Hospital, a 1,200-bed urban teaching hospital. RESULTS: Eight hundred seventy patients with HCAP were identified over a 3-year period (January 2003 through December 2005) of whom 431 (49.5%) were CP. Among the non-CP patients, 290 (66.1%) had no respiratory cultures obtained, and 149 (33.9%) had no growth or nonpathogenic oral flora identified and were classified as CN. CN patients were more likely to have received an initial antibiotic regimen (ceftriaxone +/- azithromycin or moxifloxacin) targeting community-acquired pneumonia pathogens compared with CP patients (71.8% vs 25.5%, P < .001). Severity of illness as assessed by ICU admission and mechanical ventilation (MV) was statistically lower in CN compared with CP patients (ICU admittance 12.1% vs 48.7%, P < .001; MV: 6.7% vs 44.5%, P < .001). In-hospital mortality and hospital length of stay were also statistically lower for CN patients (mortality: 7.4% vs 24.6%, P < .001; hospital length of stay: 6.7 +/- 7.4 days vs 12.1 +/- 11.7 days, P < .001). CONCLUSIONS: In this analysis, patients with CN HCAP had lower severity of illness, hospital mortality, and hospital length of stay compared with CP patients. These data suggest that patients with CN HCAP differ substantially from patients with HCAP with positive microbiologic cultures.

Salvage therapy for acute myeloid leukemia with fludarabine, cytarabine, and idarubicin with or without gemtuzumab ozogamicin and with concurrent or sequential G-CSF.

The current salvage therapies for relapsed/refractory acute myeloid leukemia (AML) are unsatisfactory. Over the past 7 years, we have used two salvage regimens: fludarabine, cytarabine, and idarubicin with (FLAG-IM) or without gemtuzumab ozogamicin (GO) (9 mg/m(2) on Day 8) (FLAG-I) in relapsed/refractory AML. Three-quarters of patients also received concurrent G-CSF. Seventy-one patients were treated, 23 with FLAG-I and 48 with FLAG-IM. The median duration of follow-up was 30.6 months. The treatment groups were well balanced with median ages of 48 years (range 18-70) and 47 years (range 20-68), unfavorable cytogenetics in 57% and 35%, prior allogeneic stem cell transplant in 43% and 42%, and CR1 duration <1 year in 60% and 67%, respectively, for FLAG-I and FLAG-IM. The complete remission (CR) rate in the FLAG-I group was 39% with an additional 13% achieving a CRp [overall response rate (ORR) 52%]; the CR rate in the FLAG-IM group was 29% with an additional 27% achieving a CRp (ORR 56%). The median duration of response (DOR; 16.8 vs. 8.3 months), event-free survival (EFS; 7.4 vs. 4.1 months), and overall survival (OS; 8.8 vs. 5.0 months) trended to favor FLAG-I over FLAG-IM. The patients who received G-CSF concurrent with chemotherapy had superior overall response rate (ORR; 62% vs. 29%, P = 0.026), median EFS (6.2 vs. 3.4 months, P = 0.010), and OS (8.8 vs. 3.9 months, P = 0.004) when compared with those who sequentially received G-CSF and chemotherapy, regardless of chemotherapy regimen. The addition of GO, at this dose and schedule, to FLAG-I failed to improve the outcomes in patients with relapsed/refractory AML. The patients who received G-CSF concurrently with chemotherapy had improved outcomes. Am. J. Hematol., 2009. (c) 2009 Wiley-Liss, Inc.

Computerized surveillance for adverse drug events in a pediatric hospital.

There are limited data on adverse drug event rates in pediatrics. The authors describe the implementation and evaluation of an automated surveillance system modified to detect adverse drug events (ADEs) in pediatric patients. The authors constructed an automated surveillance system to screen admissions to a large pediatric hospital. Potential ADEs identified by the system were reviewed by medication safety pharmacists and a physician and scored for causality and severity. Over the 6 month study period, 6,889 study children were admitted to the hospital for a total of 40,250 patient-days. The ADE surveillance system generated 1226 alerts, which yielded 160 true ADEs. This represents a rate of 2.3 ADEs per 100 admissions or 4 per 1,000 patient-days. Medications most frequently implicated were diuretics, antibiotics, immunosuppressants, narcotics, and anticonvulsants. The composite positive predictive value of the ADE surveillance system was 13%. Automated surveillance can be an effective method for detecting ADEs in hospitalized children.