Staphylococcus aureus and Other Bacteremias in Hemodialyis Patients: Antibiotic Therapy and Surgical Removal of Access Site

Summary Background: Bacteremia is commonplace in patients undergoing hemodialysis since the vascular access site is a ready source of infection. Mortality is notably high. However, uncertainties exist with respect to therapy including indications for surgical removal of vascular access site and duration of therapy. We therefore conducted a large-scale collaborative study of bacteremia in hemodialysis patients in six US academic medical centers to define the epidemiology of such infections and to address issues of management. Patients and Methods: We conducted a prospective observational study over 2 years. Severity of illness at onset of bacteremia was defined by objective criteria. Patients were followed for 90 days to assess late complications including endocarditis and mortality. Univariate and multivariate analyses were used to assess risk factors for mortality. Results: Patients experiencing 127 consecutive episodes of bacteremia were enrolled. The most common cause of bacteremia was Staphylococcus aureus (31%), followed by aerobic gram-negative bacilli (28%) and coagulase-negative staphylococci (13%). Polymicrobial bacteremia occurred in 6% of patients. The most frequent focus of infection was the access site for hemodialysis, although urinary tract, gastrointestinal tract and lung were also implicated. Aerobic gram-negative bacilli and enterococci usually originated from the urinary tract. S. aureus was significantly more likely to cause infection of the access site than other bacteria (p = 0.0001). S. aureus endocarditis was diagnosed in two patients who were receiving antibiotic therapy for S. aureus bacteremia. Removal of the infected access site (shunt, fistula, catheter) was performed for 86% of the patients (95% of the intravenous catheters and 80% of the arteriovenous fistulas/shunts). Overall mortality was 33% at 90 days and was significantly associated with severity of illness at onset of antibiotic therapy and age > 60 years. Mortality was not significantly different in patients undergoing surgical removal of infected access site versus those treated with antibiotics alone. Conclusion: When S. aureus was isolated from the blood, the access site was the most frequent source. Surgical removal of the access site did not have a notable impact on mortality. Until a randomized trial proves otherwise, it appears that surgical removal of the access site can be individualized. Selected patients who are less severely ill (based on objective criteria) can maintain their hemodialysis access site and be treated with 2 wweks of antibiotic therapy. Received: February 28, 2000 · Revision accepted: October 9, 2000     

Staphylococcus aureus bacteremia and endocarditis: the Grady Memorial Hospital experience with methicillin-sensitive S aureus and methicillin-resistant S aureus bacteremia

Background

Staphylococcus aureus has become the leading cause of endocarditis in most published series, and nosocomial acquisition is becoming more frequent. Previous studies involved community acquired methicillin-sensitive S aureus (MSSA), but recently, methicillin-resistant S aureus(MRSA) infection has increased. This may reflect the growing presence of this microorganism in clinical practice. Few data exist comparing the relative rates of endocarditis with MSSA and MRSA bacteremia. The purpose of this study was to compare these rates in a bacteremic population referred for diagnostic echocardiography.

Methods

Since July 1999, the demographic and clinical information of 104 consecutive patients with at least 2 blood cultures with positive results for S aureus who were referred for echocardiography to be evaluated for endocarditis at Grady Memorial Hospital (Atlanta, Ga) have been entered into a database. This database has further been restricted to patients who have undergone either a transesophageal echocardiogram or a transthoracic echocardiogram.

Results

Of the 104 patients with S aureus bacteremia, 53 had an infection of MSSA and 51 had an infection of MRSA. There were 33 patients (31.7%) with echocardiographically confirmed endocarditis, 23 patients (43.4%) in the MSSA group versus10 patients (19.6%) in the MRSA group (P <.009). Community-acquired MSSA bacteremia was the cause of most of the community-acquired S aureus endocarditis (20 patients [87%] vs 3 patients [30%], P = .004), and the nosocomial-acquired MRSA bacteremia was the cause of most of the nosocomial-acquired S aureus endocarditis (3 patients [13%] vs 7 patients [70%], P = .0001).

Conclusion

Our study confirms that S aureus bacteremia is associated with high rates of endocarditis. MSSA bacteremia is associated with higher rates of endocarditis than MRSA. Community MSSA is the cause of most of the community endocarditis, whereas nosocomial MRSA is the cause of most of the MRSA endocarditis. Patients with S aureus bacteremia should be aggressively evaluated for endocarditis.     

Ecthyma gangrenosum caused by Staphylococcus aureus in hematological malignancies: Case reports and literature review

Rationale:Ecthyma gangrenosum (EG) is a potentially life-threatening, systemic infection generally caused by Pseudomonas aeruginosa. Data on EG caused by Staphylococcus aureus in patients with hematological malignancies are scarce. The present case report aimed to describe the clinical features of EG caused by S. aureus in patients with hematological malignancies and to provide a comprehensive review of previous studies on the topic.Patient concerns:The first patient was a 61-year-old man with acute myeloid leukemia who presented fever and multiple lesions during chemotherapy. The second patient was a 47-year-old man with myelodysplastic syndrome who developed progressive erythematous necrotic plaques on his extremities and face.Diagnosis:Both cases were diagnosed as EG caused by S. aureus. While the first patient had concurrent methicillin-resistant S. aureus (MRSA) bacteremia, the second patient had positive results only for tissue culture of the skin lesion isolated methicillin-sensitive S. aureus.Interventions:Vancomycin was initiated with critical care to the first patient. Cefazolin was administered to the second patient for 3 weeks, followed by cephalexin for 1 week.Outcomes:The first patient died of a brain hemorrhage and multiple organ failure. The second patient was cured without relapse.Lessons:Of 18 patients in the previous and current studies with EG caused by S. aureus, 6 (33%) had an underlying hematological malignancy, and 10 (56%) had EG caused by MRSA. While 28% of the patients had positive blood cultures, all tissue cultures were positive. All 3 fatalities had concurrent bacteremia (MRSA caused two). EG caused by MRSA with concurrent bacteremia can be fatal, especially in patients with hematological malignancies. Although S. aureus-associated EG in patients with hematological malignancies is relatively uncommon, tissue cultures with an initial gram stain smear are essential for selecting appropriate empirical antimicrobials, including the coverage of S. aureus.     

Production of biofilm by Staphylococcus aureus: Association with infective endocarditis?

ObjectivesStaphylococcus aureus is a well-known biofilm-producing pathogen that is capable of causing chronic infections owing to its ability to resist antibiotic treatment and obstruct the immune response. However, the possible association between high biofilm production and infective endocarditis (IE) has not been assessed. Our objective was to compare production of biofilm by S. aureus strains isolated from patients with bacteremia and IE, catheter-related bloodstream infection (C-RBSI), or non-device associated bacteremia.MethodsWe isolated 260 S. aureus strains from the blood of patients with bacteremia who were diagnosed during hospital admission between 2012 and 2015. Patients were divided into 3 groups according to whether they had IE, C-RBSI, or non-device associated bacteremia. Biofilm production was measured in terms of biomass and metabolic activity using the crystal violet and XTT assays, respectively. High biomass and metabolic activity rates (based on tertile ranks classification) were compared between the 3 groups.ResultsThe high biomass and metabolic activity rates of each group were 41.9% and 37.2% for IE, 32.5% and 35.0%, for C-RBSI, and 29.0% and 33.3% for non-device associated bacteremia (p = 0.325 and p = 0.885, respectively).ConclusionsHigh biomass and metabolic activity levels for S. aureus isolates from IE were similar to those of S. aureus isolates from C-RBSI or non-device associated bacteremia.     

Hodgkin lymphoma in Tyrol—a population-based study

We aimed to analyze the epidemiology, clinical characteristics, and outcome of patients with Hodgkin lymphoma (HL) diagnosed in Tyrol. All patients with newly diagnosed HL between 1993 and 2005 were included in this study. Among the 158 cases included, nodular lymphocytic predominant HL (nodular paragranuloma) was identified in ten cases (6%) whereas the majority of patients had classical Hodgkin lymphoma. Age (p < 0.01), sex (p = 0.03), risk groups according to the German Hodgkin Study Group stratification (p < 0.01), and bone marrow infiltration (p < 0.01) were of prognostic significance considering overall survival (OS) whereas histological subtype and bulky disease were not. The 5- and 10-year OS rates for the total group were 89% and 85%, respectively. Notably, in patients with advanced-stage HL (n = 49), combined modality treatment resulted in significantly better OS than chemotherapy alone (p = 0.01). Three patients developed a second hematological malignancy and one patient developed breast cancer. However, five patients (3%) had a malignant hematological disorder before occurrence of HL. Concerning treatment-related toxicity, bleomycin-associated lung toxicity was observed in six (4%) patients and five (3%) developed lethal treatment-related infectious complications. Our results provide evidence that the incidence rate of HL in Tyrol is comparable to other Western countries. Modern risk-adapted treatment results in excellent long-term prognosis but may be complicated by serious nonhematological side effects, in particular, infections and bleomycin-induced lung toxicity. Furthermore, 3% of HL patients had an antecedent malignant hematological disease before occurrence of HL.     

Infective Endocarditis in Intravenous Drug Users from Italy: the Increasing Importance in HIV-infected Patients

Abstract Background: Intravenous drug users (IDUs) are at increased risk of infective endocarditis (IE). Patients and Methods: Episodes of IE in IDUs were retrospectively analyzed in this multicenter study. Cases were collected between 1986 and 1999. Only definite diagnosis according to the Duke criteria were analyzed. Results: Two hundred and sixty-three cases, including 100 cases in HIV-positive patients, were observed in IDUs. Any right-sided involvement was detected in 167 out of 263 cases (63.5%) and any left-sided involvement in 115 out of 263 cases (43.7%). The tricuspid valve (TV) alone was affected in 135 cases (51.3%), the mitral valve alone in 32 patients (12.1%), the aortic valve alone in 41 cases (15.6%) and the pulmonic valve alone in 3 cases. Staphylococcus aureus was isolated in 156 cases (59.3%) and Streptococcus spp. in 33 cases (12.5%). No major differences were observed between HIV-negative and HIV-positive patients. Any TV valve involvement was significantly associated with female rather than male gender (p = 0.02). There was a significant association between S. aureus etiology and TV involvement (p < 0.0001). The mortality rate was 16%. On multivariate analysis, only left-side IE (p = 0.0006; OR 5.2; 95% CI 2.0–13.5) and age greater than 35 years (p = 0.0068; OR 3.6; 95% CI 1.4–9.0) were independently associated with mortality. Conclusions: Infective endocarditis in IDUs is significantly associated with right-side localization (63.5% for any rightsided heart involvement vs 43.7% for any left-sided heart involvement; OR 2.24; 95% CI 1.55–3.23; p < 0.001). S. aureus is the microorganism most frequently isolated and is significantly associated with TV involvement. Any left-side involvement and age greater than 35 years are independently associated with mortality. HIV infection does not appear to have a significant effect on mortality.     

Risk Factors and Clinical Outcomes for Patients With Acinetobacter baumannii Bacteremia

Acinetobacter (A.) baumannii, an opportunistic nosocomial pathogen that can cause significant morbidity and mortality, has emerged as a worldwide problem. This study aimed to analyze the clinical features and outcomes of patients with A. baumannii bacteremia and determine the factors influencing survival by using 14-day mortality as the primary endpoint.A 6-year retrospective study of 122 cases with monomicrobial A. baumannii bacteremia was conducted in Chinese People''s Liberation Army (PLA) General Hospital from January 2008 to April 2014. Predictors of 14-day mortality were identified by logistic regression analysis.The overall 14-day mortality rate was 40.2% (49 of 122 patients). Multivariable analysis revealed that independent predictors of 14-day mortality included severity of illness defined by Pitt Bacteremia Score (PBS) (odds ratio [OR], 0.46; 95% confidence interval [CI], 0.340–0.619; P < 0.001), neutropenia (OR, 18.02; 95% CI, 1.667–194.67; P = 0.017), and malignancy (OR, 4.63; 95% CI, 1.292–16.588; P = 0.019). The effect of malignancy was influenced by neutropenia (OR for interaction term, 1.60; 95% CI, 1.15–2.22; P = 0.005). A subgroup analysis revealed that 14-day mortality rate for patients with underlying hematological malignancies and solid tumors was 75% (12/16) and 40% (12/30), respectively. Survival analysis revealed that mortality in patients with hematological malignancies was higher than that in patients with solid tumors (P = 0.032).The outcomes of patients with A. baumannii bacteremia were related to PBS, neutropenia, and malignancy. Compared with solid tumors, patients with hematological malignancies had a higher mortality in the setting of A. baumannii bacteremia.     

Predictive factors of septic shock and mortality in neutropenic patients

Neutropenia is a major risk factor for developing a serious infection. Bacteremia still causes significant mortality among neutropenic patients with cancer. The purpose of this study was to identify risk factors for septic shock and for mortality in neutropenic patients with leukemia and bacteremia. Consecutive samples from 20 patients with acute myeloid leukemia and bacteremia were studied during a 1 year period (January–December 2003). All patients received empirical antibiotic therapies for febrile episodes using ceftazidime plus amikacin. About 110 neutropenic febrile episodes were noted: clinically documented 14.54%, microbiologically documented 16.36% and fever of unknown origin 69.09%. Gram-negative organism caused eight febrile episodes: Pseudomonas (5), Klebsiella (3). Gram-positive organism caused 10 episodes: Staphylococcus (6), Streptococci (2), Enterococci (2). Pulmonary infection accounted for 25% of clinically documented infections. About 14 of the 110 febrile episodes were associated with septic shock causing mortality in 7 patients. In a univariate analysis variables associated with septic shock were: pulmonary infection (OR = 17, p = 0.001), serum bicarbonate < 17 mmol/l (OR = 68, p < 0.001) and serum lactate >3 mmol/l (OR = 62, p < 0.001). Variables associated with mortality were: pulmonary infection (OR = 83, p < 0.001) and serum bicarbonate < 17 mmol/l (OR = 61, p < 0.001).

In a multivariate analysis two variables were associated with septic shock: pulmonary infection (OR = 5, p = 0.043) and serum lactate >3 mmol/l (OR = 10, p = 0.003). An elevated serum lactate (>3 mmol/l) and low serum bicarbonate (< 17 mmol/l) at the onset of bacteremia are useful biomarkers in predicting septic shock and mortality in neutropenic patients.     

Non-fermentative Gram-negative rods bacteremia in children with cancer: a 14-year single-center experience

Purpose

Data on non-fermentative Gram-negative rods (NFGNR) bacteremia in children with malignancies are limited. The aim of this study was to present clinical picture, antimicrobial susceptibility pattern, risk factors for resistance and outcome in NFGNR bacteremia in children with cancer.

Methods

All episodes of NFGNR bacteremia occurring during 2001–2014 in children with cancer in a tertiary-care hospital were retrospectively analyzed. Pseudomonas and Acinetobacter spp. resistant to three or more antibiotic classes and all Stenotrophomonas maltophilia (SM) were defined as multidrug-resistant bacteria (MDR).

Results

A total of 80 children (44 males, 0.8–18 years, median 5 years) developed 107 episodes (116 pathogens) of NFGNR bacteremia; Pseudomonas aeruginosa (PA) (51; 43.9%), Acinetobacter baumannii (AB) (21, 18.1%), SM (18, 15.5%); and others (27, 25.2%). The rate of NFGNR bacteremia in children with certain solid tumors (e.g. sarcoma, 12/134 (9.0%)) was comparable to that of hematological malignancies (52/429 (12.2%). Focal infection and septic shock occurred in 16 (14.9%) and four (3.7%) episodes, respectively. Thirty (25.8%) of 116 NFGNR were MDR. The most significant predictors of bacteremia with MDR PA or AB were severe neutropenia (<100 cells/mm³; OR 7.8, p = 0.002), hospital-acquired (OR 16.9, p < 0.0001) and breakthrough (OR 11.2, p < 0.0001) infection. Infection with MDR bacteria was associated with inappropriate empirical therapy. The 30-day mortality was 3/107 (2.8%), all in neutropenic patients with hematological malignancies.

Conclusions

NFGNR bacteremia can present with nonspecific signs or symptoms. MDR NFGNRs are common and compromise treatment options, but mortality is relatively low. Knowledge of local epidemiology, pattern and risk factors for resistance is important to guide empirical therapy.

     

Which Multidrug-Resitant Bacteria are Emerging in Patients with Hematological Malignancies?: One-Year Report

The aim of this retrospective, observational study was to evaluate the outcomes of bacteremia attacks during neutropenic episodes caused by chemotherapy in patients with hematological cancers by assessing mortality, involved pathogens, antimicrobial therapy and treatment responses. Patients who were older than 14 years of age and developed at least one neutropenic episode after chemotherapy to treat hematological cancer between November 2011 and November 2012 were included in the study. We retrospectively collected demographic, treatment, and survival data for 68 patients with 129 neutropenic episodes. The mean age was 59.36 ± 15.22 years (range 17–80 years), and 41 cases were male. The mean Multinational Association of Supportive Care in Cancer score was 19.56 ± 9.04. A total of 37 (28 %) bacteremia attacks were recorded in 20 cases (29 %). Fatality rates were 50 % in the six cases with bacteremia caused by carbapenem-resistant Gram-negative bacteria; death occurred in two patients with carbapenem-resistant Acinetobacter baumannii and in one patient with carbapenem-resistant Pseudomonas aeruginosa. Clinical and microbiological responses were achieved using PIP-TAZ or CEP-SUL treatment in 80 % (16/20) of the cases with bacteremia caused by carbapenem-sensitive Gram-negative bacteria (CS-GNB). During 547 colonization-days in 21 (30 %) vancomycin-resistant enterococci (VRE)-colonized cases among 68 patients, vancomycin-resistant Enterococcus faecium bacteremia developed in two patients. Non-carbapenem-based therapy can cure most bacteremia attacks caused by CS-GNB in patients with hematological cancer. However, bacteremia and other infections caused by drug-resistant pathogens, such as A. baumannii, P. aeruginosa, and VRE, are a growing concern in hematological patients.     

Allogeneic bone marrow transplantation compared to peripheral blood stem cell transplantation for the treatment of hematologic malignancies: a meta-analysis based on time-to-event data from randomized controlled trials

Controversy remains regarding the transplant outcomes of human leukocyte antigen-identical related bone marrow transplantation (BMT) and peripheral blood stem cell transplantation (PBSCT) for the treatment of patients with hematological malignancies. To provide an estimate of the effect of BMT and PBSCT on clinical outcomes in patients with hematological malignancies, we conducted a meta-analysis based on time-to-event data from 17 randomized controlled trials. PubMed, EMBASE, and Cochrane Central Register of Controlled Trials (CENTRAL), from 1972 through July 2010, and conference proceedings through July 2009 and reference lists, without any language restriction, of randomized trials that compared the transplant outcomes after BMT and PBSCT in patients with hematological malignancies were searched for details. Two independent reviewers extracted the data. The outcomes examined were engraftment, graft-versus-host disease (GVHD), relapse, transplant-related mortality (TRM), leukemia-free-survival (LFS), and overall survival (OS). Compared to PBSCT, BMT had lower neutrophil (HR, 2.08; 95% CI, 1.80 to 2.42; p < 0.00001) and platelet (HR, 2.77; 95% CI, 1.78 to 4.30; p < 0.00001) engraftment. BMT was associated with a significant decrease in the development of grades II–IV (HR, 0.75; 95% CI, 0.63 to 0.90; p = 0.002) and III–IV (HR, 0.63; 95% CI, 0.47 to 0.84; p = 0.001) acute GVHD as well as overall (HR, 0.70; 95% CI, 0.59 to 0.83; p < 0.0001) and extensive (HR, 0.60; 95% CI, 0.39 to 0.91; p = 0.002) chronic GVHD. BMT was associated with a higher incidence of relapse (HR, 1.91; 95% CI, 1.34 to 2.74; p = 0.0004). Comparable TRM (1.08; 95% CI, 0.56 to 2.10; p = 0.81), LFS (HR, 1.04; 95% CI, 0.83 to 1.30; p = 0.73), and OS (HR, 1.06; 95% CI, 0.81 to 1.39; p = 0.65) were demonstrated for both treatments. An inverse linear relationship was observed between the acute GVHD difference (PBSCT minus BMT) and the outcome of OS (p = 0.016). Our meta-analysis suggest that BMT leads to slower hematological recovery, increasing rates of relapse, and a lower risk of GVHD, but no significant difference in LFS and OS. A lower incidence of acute GVHD is associated with a superior OS.     

Acute respiratory distress syndrome in patients with hematological malignancies

Abstract

Background

We investigated the clinical course and mortality of acute respiratory distress syndrome (ARDS) in patients with hematological malignancies.

Methods

Sixty-eight patients with hematological malignancies and ARDS admitted to medical intensive care unit (ICU) of a university hospital were analyzed semi-prospectively in the study.

Results

The most common etiology of ARDS was pneumonia. The ratio of partial pressure of oxygen in arterial blood to fractional concentration of inspired oxygen (PO₂/FiO₂) was 104 (74–165). Ten patients (15%) received non-invasive mechanical ventilation (NIV), 21 (31%) received invasive mechanical ventilation (MV), and 36 (53%) received both NIV and invasive MV. ICU mortality was 77% in the cohort. None of the variables with relevance to the underlying hematological disease was associated with mortality. The presence of two or more organ failures was the only independent risk factor for mortality (P = 0.045), whereas NIV was associated with low mortality (P = 0.001). The Kaplan–Meier curve of mortality, with respect to the type of MV support, demonstrated that NIV was associated with the lowest mortality (P < 0.001).

Conclusion

The mortality of ARDS in critically ill patients with hematological malignancies is quite high. The presence of multi-organ failure is independently associated with high mortality whereas the use of NIV is independently associated with low mortality.     

Atypical Presentation of Bacteremia in Older Patients Is a Risk Factor for Death

BackgroundThe absence of fever in bacteremia in patients who are older is known to delay diagnosis. Our objective was to determine whether atypical presentation was associated to mortality as a result of bacteremia in this patient cohort as well as possible factors associated with this atypical presentation.MethodsWe conducted an observational prospective study in 2 French university hospitals in 2016-2017 including patients ages ≥ 75 years with bacteremia. Atypical presentation was defined as the absence of a temperature ≥ 38.3°C or < 36°C, chills, or hypotension. Mortality and dependence for activities of daily living (ADL) were recorded at 1 week (D7) and 3 months (D90).ResultsAmong the 151 patients (mean age 85.4 ± 5.8 years) enrolled, atypical presentation prevalence was 21.2%. D7 and D90 mortality rates were 7.9% and 40.0%, respectively. Atypical presentation was independently associated with D7 (odds ratio (OR) 4.46, 95% confidence interval (CI) 1.04-19.24) and D90 mortality (OR 3.76, 95% CI 1.30-10.92) after controlling for other prognostic factors. Patients with diabetes and those infected with Staphylococcus aureus were more likely to have atypical signs of infection. ADL score decreased from 3.6 ± 2.0 before bacteremia to 2.8 ± 2.1 at D90 (P < 0.001).ConclusionPatients who are older with bacteremia have poor vital and functional prognoses in the short and long terms. The absence of typical signs of infection is associated with mortality. Blood culture should be considered for patients who are older, especially with diabetes with acute unexplained clinical manifestations.     

Outcomes of Staphylococcus aureus Infection in Hemodialysis-Dependent Patients

Background and objectives: Staphylococcus aureus is a leading cause of infection in patients with ESRD. Clinical and economic outcomes associated with S. aureus bacteremia and other S. aureus infections in patients with ESRD were examined.Design, setting, participants, & measurements: Laboratory, clinical, and hospital billing data from a randomized trial of 3359 hemodialysis-dependent patients hospitalized with S. aureus infection in the United States whose vascular access type was fistula or graft and who were hospitalized with S. aureus infection to evaluate inpatient costs, hospital days, and mortality over 12 wk were used. Generalized linear regression was used to identify independent predictors of 12-wk costs, inpatient days, and mortality.Results: Of the 279 patients (8.3%) who developed S. aureus infection during approximately 1 yr of follow-up, 25.4% were treated as outpatients. Among patients for whom billing data were available, 89 patients hospitalized with S. aureus bacteremia incurred mean 12-wk inpatient costs of $19,454 and 11.9 inpatient days. Among the 70 patients hospitalized with non-bloodstream S. aureus infections, mean inpatient costs were $19,222 and the mean number of inpatient days was 11.3. Twelve-week mortality was 20.2 and 15.7% for patients with S. aureus bloodstream and non-bloodstream infections, respectively. Older age was independently associated with higher risk of death among patients with S. aureus bacteremia and with higher inpatient costs and more hospital days among patients with non-bloodstream infections.Conclusions: Hemodialysis-dependent patients with fistula or graft access incur high costs and long inpatient stays when hospitalized for S. aureus infection.Patients with ESRD on maintenance hemodialysis are at a greater risk for bacterial infection, particularly Staphylococcus aureus infection (1–7). The annual incidence of S. aureus bacteremia in patients on hemodialysis ranges from 6 to 27% (3,8,9). Complications of S. aureus bacteremia include meningitis, endocarditis, osteomyelitis, and metastatic abscesses (10–12). Patients with ESRD who acquire S. aureus bacteremia are at greater risk of death than patients in whom bacteremia is attributable to other organisms (13).Recently, a large, multicenter, randomized clinical trial was conducted to evaluate the efficacy and safety of a vaccine intended to reduce the incidence of S. aureus infection in adults with ESRD undergoing hemodialysis with a native-vessel fistula or synthetic or heterologous tissue graft. The trial incorporated a prospective economic evaluation. Although the vaccine was not efficacious in the study, the availability of clinical and economic data from numerous sites in the United States provided a unique opportunity to accurately examine patient characteristics associated with S. aureus infection, as well as inpatient costs, inpatient days, and mortality for patients hospitalized with S. aureus bacteremia and other types of S. aureus infection.     

Association Between Staphylococcus aureus Bacteremia and Hospital Mortality in Hemodialysis Patients With Bloodstream Infection: A Multicenter Cohort From Japanese Tertiary Care Centers

Multiple studies have shown that Staphylococcus aureus bacteremia (SAB) has been a major cause of death in hemodialysis patients. We examined whether SAB is a risk for mortality among chronic hemodialysis patients in Japan where the standard vascular access is arteriovenous fistula (AVF). This was a multicenter, retrospective study of maintenance hemodialysis patients with bloodstream infection (BSI) from 2011 to 2013 at tertiary care centers in Japan. The endpoint was hospital mortality. Our cohort contained 32 SAB cases (14 MRSA and 18 MSSA) and 42 non‐SAB cases. Hospital mortality was higher among SAB cases than non‐SAB cases (46.9% vs. 23.8%, P = 0.038). In patients with BSI, SAB was significantly associated with hospital mortality after adjustment for potential confounders, including type of vascular access (OR 3.26). S. aureus was the leading cause of BSI and hospital mortality among this cohort. Therefore, initial empiric treatment should cover for S. aureus.     

Meropenem monotherapy versus combination therapy with ceftazidime and amikacin for empirical treatment of febrile neutropenic patients

 Infections remain the major cause of morbidity and mortality among neutropenic cancer patients. The current study addresses the question whether monotherapy with the new broad-spectrum carbapenem meropenem exhibits efficacy comparable to that of the standard combination therapy with ceftazidime and amikacin for empirical treatment of febrile neutropenic patients. Seventy-one patients with hematological malignancies (55%) or solid tumors (45%), neutropenia <500/μl, and fever <38.5  °C were randomly assigned to either meropenem (1 g every 8 h) or ceftazidime (2 g every 8 h) and amikacin (15 mg/kg/day) intravenously. Meropenem (n=34) and ceftazidime/amikacin (n=37) were equivalent with respect to the clinical response at 72 h (62% versus 68%) (p<0.05) and at the end of unmodified therapy (59% versus 62%). Gram-positive bacteremia responded poorly in the meropenem and ceftazidime/amikacin group (29% versus 25%), whereas all gram-negative bacteremias responded except for one in the meropenem group caused by Pseudomonas aeruginosa. All patients survived to 72 h. One patient in each group died of gram-positive sepsis resistant to study medication. No significant side effects occurred in any regimen. This study suggests that meropenem monotherapy might be as effective as combination therapy with ceftazidime and amikacin for the empirical treatment of febrile neutropenic patients. Received: 13 June 1997 / Accepted in revised form: 5 December 1997     

Cardiac device-related endocarditis: 31-Years’ experience

BackgroundCardiac device-related endocarditis (CDE) is a major complication of the implantation of a pacemaker and defibrillator. The experience in a single high-volume tertiary center is reported.MethodsThirty one years (1980–2011) of cases of CDE were analyzed retrospectively and compared to overall insertion data; the clinical course and management strategies of these patients have been reviewed.ResultsA total of 23 cases (16 male, median age 72 years) were identified, 20 of these cases were determined at our institution where 5287 procedures were performed (endocarditis rate 0.38%). Thirteen patients were determined to have a cardiac device pocket infection. Infection in 7 cases (30%) was caused by lead(s). However, in 16 cases (70%) both leads and the pocket of devices were the reason of infection. Median time was 13.5 months for presentation. Patients who had undergone the last procedure within 6 months were admitted earlier than those with longer post procedure time (p < 0.05). Transesophageal echocardiography demonstrated lead vegetations in 13 of the 16 cases (81%). Organisms were identified in 18 cases (78%)—78% Staphylococci (56% Staphylococcus aureus). Leads of the device were removed in 17 cases (74%); seven cases by percutaneous simple traction and 10 cases by sternotomy. Six major complications attributable to device-related endocarditis were observed: four deaths (mortality 17.4%); one splenic abscess requiring splenectomy; and one septic pulmonary embolism; median follow-up 49 months.ConclusionA CDE endocarditis rate of 0.38% was demonstrated. It remains a rare but potentially lethal complication of device implantation.     

A prospective multicenter study of Staphylococcus aureus bacteremia: incidence of endocarditis, risk factors for mortality, and clinical impact of methicillin resistance

Our objectives were to determine the incidence of endocarditis in patients whose Staphylococcus aureus bacteremia was community-acquired, related to hemodialysis, or hospital-acquired; to assess clinical factors that would reliably distinguished between S. aureus bacteremia and S. aureus endocarditis; to assess the emergence of methicillin-resistant S. aureus (MRSA) as a cause of endocarditis; and to examine risk factors for mortality in patients with S. aureus endocarditis.We conducted a prospective observational study in 6 university teaching hospitals; we evaluated 505 consecutive patients with Staphylococcus aureus bacteremia. Thirteen percent of patients with S. aureus bacteremia were found to have endocarditis, including 21% with community-acquired S. aureus bacteremia, 5% with hospital-acquired bacteremia, and 12% on hemodialysis. Infection was due to MRSA in 31%.Factors predictive of endocarditis included underlying valvular heart disease, history of prior endocarditis, intravenous drug use, community acquisition of bacteremia, and an unrecognized source. Twelve patients with bacteremia had a prosthetic valve; 17% developed endocarditis. Unexpectedly, nonwhite race proved to be an independent risk factor for endocarditis by both univariate and multivariate analyses. Persistent bacteremia (positive blood cultures at day 3 of appropriate therapy) was identified as an independent risk factor for both endocarditis and mortality, a unique observation not reported in other prospective studies of S. aureus bacteremia.Patients with endocarditis due to MRSA were significantly more likely to have complicating renal insufficiency and to experience persistent bacteremia than those with endocarditis due to MSSA. The 30-day mortality was 31% among patients with endocarditis compared to 21% in patients who had bacteremia without endocarditis (p = 0.055). Risk factors for death due to endocarditis included severity of illness at onset of bacteremia (as measured by Apache III and Pitt bacteremia score), MRSA infection, and presence of atrioventricular block on electrocardiogram.Patients with S. aureus bacteremia who have community acquisition of infection, underlying valvular heart disease, intravenous drug use, unknown portal of entry, history of prior endocarditis, and possibly, nonwhite race should undergo echocardiography to screen for the presence of endocarditis. We recommend that blood cultures be repeated 3 days following initiation of antistaphylococcal antibiotic therapy in all patients with S. aureus bacteremia. Positive blood cultures at 3 days may prove to be a useful marker in promoting more aggressive management, including more potent antibiotic therapy and surgical resection of the valve in endocarditis cases. MRSA as the infecting organism should be added to the list of risk factors for consideration of valvular resection in cases of endocarditis.     

Clinical manifestations and outcome in Staphylococcus aureus endocarditis among injection drug users and nonaddicts: a prospective study of 74 patients

Background  

Endocarditis is a common complication in Staphylococcus aureus bacteremia (SAB). We compared risk factors, clinical manifestations, and outcome in a large, prospective cohort of patients with S. aureus endocarditis in injection drug users (IDUs) and in nonaddicts.     

Relationship between Serum CK-MB-Estimated Acute Myocardial Infarct Size and Clinical Complications

ABSTRACT The relationship between acute myocardial infarct (AMI) size and morbidity and mortality was estimated in 317 patients followed for one year or until death. Infarct size was estimated from serum creatine kinase (CK)-MB levels measured thrice daily. The incidence of ventricular arrhythmias, congestive heart failure, cardiogenic shock, and the cardiac performance during exercise were studied during hospitalization. Hospital mortality and one-year mortality were registered. A positive correlation was found between serum CK-MB-estimated infarct size and the incidence of ventricular arrhythmias (p<0.05). Patients with congestive heart failure and patients with cardiogenic shock had significantly larger infarct size than patients without (p<0.05–0.01), although there was a substantial overlap. During exercise test the rise in systolic blood pressure correlated negatively and the rise in heart rate correlated positively to estimated infarct size (p<0.01). Both hospital mortality and one-year mortality were significantly related to estimated infarct size (p<0.01). Thus the infarct size, as estimated from serum CK-MB, seems to be of importance for development of the most common and serious complications after AMI.