Independent Predictors Of Bacteremia Research Articles

Proportion of Neutrophils in White Blood Cells as a Useful Marker for Predicting Bacteremic Acute Cholangitis.

Objective A positive hemoculture in acute cholangitis is serious, but a blood culture result cannot be obtained at the initial diagnosis and so cannot be used for the severity assessment and decision-making concerning urgent/early biliary drainage. Accordingly, a predictor for bacteremia at the initial diagnosis of acute cholangitis would be particularly useful. We investigated the association between neutrophil proportions in white blood cell counts (%Neutro) and bacteremic acute cholangitis. Methods Of 166 patients with acute cholangitis who were diagnosed with the Tokyo guidelines 2018/2013 from April 2015 to March 2017, a total of 94 underwent blood culture assessments and were divided into those with a positive hemoculture (n=48) and a negative hemoculture (n=46) and then compared. A receiver operating characteristic curve analysis was used to evaluate the predictive ability of %Neutro and other inflammatory markers. Results The %Neutro values were significantly higher in the positive hemoculture group than in the negative hemoculture group (91.7% ±4.0% vs. 82.5% ±9.0%, P<0.0001). A cut-off %Neutro value of 89.7% was strongly associated with bacteremia (area under the curve 0.86, sensitivity 77.1%, specificity 80.4%). A %Neutro of ≥89.7% was a predictor of a positive hemoculture in univariate (P<0.0001) and multivariate analyses (P<0.001). Patients with a %Neutro ≥89.7% needed early biliary drainage more frequently than others (30/46, 65.2% vs. 18/48, 37.5%, p=0.0063). Conclusions %Neutro is an independent predictor of bacteremia in patients with acute cholangitis and may contribute to decision-making concerning early biliary drainage.

Hypoglycemia is an early, independent predictor of bacteremia and in-hospital death in patients with cirrhosis.

Bacteremia is a common cause of death in patients with cirrhosis and early antimicrobial therapy can be life-saving. Severe liver disease impairs glucose metabolism such that hypoglycemia may be a presenting sign of infection in patients with cirrhosis. We explored this association using granular retrospective data. We conducted a case-control analysis from 1 January 2008 to 31 December 17 in the University of Pennsylvania Health System. We identified the first blood culture results from all cirrhosis hospitalizations and obtained detailed vital sign and laboratory data in the 24-72 h prior to culture results. We used multivariable logistic regression to develop models predicting blood culture positivity and in-hospital mortality. We repeated these analyses restricted to normothermic individuals. Restricted cubic splines were used to model nonlinearity in the glucose variable. We identified 1274 cirrhosis admissions with blood culture results (52.7% positive). In adjusted models, minimum glucose 24-72 h prior to blood culture result date was a significant predictor of blood culture positivity. In particular, glucose levels below 100 mg/dL significantly increased the probability of subsequent positive blood culture (e.g. odds ratio 1.89 for 50 mg/dL vs. 100 mg/dL, P = 0.004). This relationship persisted when restricting the cohort to normothermic individuals. Glucose levels <100 mg/dL in patients with bacteremia were also positively associated with in-hospital mortality. Early hypoglycemia is predictive of subsequently documented bacteremia and in-hospital mortality in patients with cirrhosis, even among normothermic individuals. In patients without other overt signs of infection, low glucose values may serve as an additional data point to justify early antibiosis.

Rate and Predictors of Bacteremia in Afebrile Community-Acquired Pneumonia

Although blood cultures (BCs) are the "gold standard" for detecting bacteremia, the utility of BCs in patients with community-acquired pneumonia (CAP) is controversial. This study describes the proportion of patients with CAP and afebrile bacteremia and identifies the clinical characteristics predicting the necessity for BCs in patients who are afebrile. Bacteremia rates were determined in 4,349 patients with CAP enrolled in the multinational cohort study The Competence Network of Community-Acquired Pneumonia (CAPNETZ) and stratified by presence of fever at first patient contact. Independent predictors of bacteremia in patients who were afebrile were determined using logistic regression analysis. Bacteremic pneumonia was present in 190 of 2,116 patients who were febrile (8.9%), 101 of 2,149 patients who were afebrile (4.7%), and one of 23 patients with hypothermia (4.3%). Bacteremia rates increased with the CURB-65 score from 3.5%in patients with CURB-65 score of 0 to 17.1%in patients with CURB-65 score of 4. Patients with afebrile bacteremia exhibited the highest 28-day mortality rate (9.9%). Positive pneumococcal urinary antigen test (adjusted OR [AOR], 4.6; 95%CI, 2.6-8.2), C-reactive protein level > 200mg/L (AOR, 3.1; 95%CI, 1.9-5.2), and BUN level≥ 30mg/dL (AOR, 3.1; 95%CI, 1.9-5.3) were independent positive predictors, and antibiotic pretreatment (AOR, 0.3; 95%CI, 0.1-0.6) was an independent negative predictor of bacteremia in patients who were afebrile. A relevant proportion of patients with bacteremic CAP was afebrile. These patients had an increased mortality rate compared with patients with febrile bacteremia or nonbacteremic pneumonia. Therefore, the relevance of fever as an indicator for BC necessity merits reconsideration.

Significance of blood cultures in nursing home-acquired pneumonia.

The significance of blood cultures in nursing home-acquired pneumonia (NHAP) is incompletely understood. We retrospectively analyzed the clinical and laboratory features of 515 patients with NHAP admitted to our hospital over an 11-year period. Blood cultures were obtained from 336 patients (65.2%). We compared 13 and 323 patients with positive and negative blood cultures, respectively. The former showed lower systolic blood pressure and higher blood urea nitrogen (BUN), creatinine, C-reactive protein (CRP), and A-DROP scores than the latter. With regard to A-DROP parameters, patients with positive blood cultures showed significantly higher rates of dehydration (BUN≥21mg/dL) and low blood pressure (systolic blood pressure≤90mmHg). Multivariate analysis identified CRP values and low blood pressure as independent predictors of bacteremia: CRP (odds ratio [OR] 1.11; 95% confidence interval [CI] 1.04-1.19, P=0.003) and low blood pressure (OR 6.03; 95% CI 1.06-34.25, P=0.04). A receiver operating characteristic curve indicated that CRP was of moderate accuracy (area under the curve=0.75), and its diagnostic accuracy was optimal at a cut-off point of 19.2mg/dL (sensitivity 69%, specificity 87%). Since the probability of true bacteremia is very low in NHAP, obtaining blood cultures from all patients with NHAP is unnecessary. However, our results suggest blood cultures are warranted from patients with high CRP values (≥20mg/dL) or low blood pressure.

Parameters for Ordering Blood Cultures in Major Burn Injury Patients: Improving Clinical Assessment.

Hypermetabolic and catabolic states in large TBSA burns lead to higher basal body temperature and tachycardia. These metabolic changes complicate the diagnosis of bacteremia and sepsis. Current indications for obtaining blood cultures (BCs) in this population are poorly described and nonstandardized. Fever, leukocytosis, and lactic acidosis are common during sepsis. This study aims to identify limits of these parameters with the highest rates of bacteremia. A retrospective review was performed for burn patients with > 20% TBSA between January 2009 and June 2011. BCs were collected with corresponding body temperature, white blood cell (WBC) count, and serum lactate levels. Positive culture rates were analyzed with univariate and multivariate analysis. Seventy-one patients met inclusion criteria and 360 BCs were included in data analysis. Cultures taken with temperature > 38.9°C were significantly more positive (P = .01) than temperatures between 38 and 38.9°C. There were significantly more positive cultures when the WBC count was < 4.5 compared with those ≥ 4.5 × 103/µl (P = .04). Lactate was an independent predictor of bacteremia (OR, 1.81; 95% CI, 1.21-12.71). Cultures were significantly more positive when the lactate level was ≥ 2.5 compared with < 2.5 mg/dL (P = .02). A temperature ≥ 38.5°C and a lactate ≥ 2.5 mg/dL corresponded to a 28.6% positive culture rate compared with 4.8% for all other scenarios (P = .001). This study demonstrates that body temperature > 38.9°C, WBC < 4.5 × 103/µl, and serum lactate ≥ 2.5 mg/dL have the highest rate for positive BCs in severe burn patients. A combination of leukopenia and pyrexia as well as lactic acidosis and pyrexia represent even higher specificity for positive BC in these patients.

Risk Factors for Bacteremia in Patients With Urinary Catheter-Associated Bacteriuria.

Catheter-associated bacteriuria is complicated by secondary bacteremia in 0.4% to 4.0% of cases. The directly attributable mortality rate is 12.7%. To identify risk factors for bacteremia associated with catheter-associated bacteriuria. Data were acquired from a large electronic clinical and administrative database of consecutive adult inpatient admissions to 2 acute care hospitals during a 7-year period. Data on patients with catheter-associated bacteriuria and bacteremia were compared with data on control patients with catheter-associated bacteriuria and no bacteremia, matched for date of admission plus or minus 30 days. Urine and blood cultures positive for the same pathogen within 7 days were used to define catheter-associated bacteriuria and bacteremia. Multivariable conditional logistic regression was used to determine independent risk factors for bacteremia. The sample consisted of 158 cases and 474 controls. Independent predictors of bacteremia were male sex (odds ratio, 2.76), treatment with immunosuppressants (odds ratio, 1.68), urinary tract procedure (odds ratio, 2.70), and catheter that remained in place after bacteriuria developed (odds ratio, 2.75). Patients with enterococcal bacteriuria were half as likely to become bacteremic as were patients with other urinary pathogens (odds ratio, 0.46). Odds of secondary bacteremia increased 2% per additional day of hospital stay (95% CI, 1.01-1.04) and decreased 1% with each additional year of age (95% CI, 0.97-0.99). The results add new information about increased risk for bacteremia among patients with catheters remaining in place after catheter-associated bacteriuria and confirm evidence for previously identified risk factors.

Bacteremia Among Febrile Ugandan Children Treated with Antimalarials Despite a Negative Malaria Test.

Bacteremia may be inappropriately treated as malaria in children admitted with a febrile illness in Africa. We determined the prevalence, clinical features, and spectrum of bacteremia among febrile children younger than 5 years of age admitted with a negative malaria test, but prescribed antimalarials at a referral hospital in Jinja, Uganda. After initial evaluation, a blood sample was drawn from 250 children for a complete blood count and bacterial culture. Of 250 samples cultured, 15 grew organisms presumed to be skin contaminants, and of the remaining 235 samples, 45 (19.1%) had bacteremia. Staphylococcus aureus (42%), non-typhoidal Salmonella (24%), Pseudomonas aeruginosa (11%), and Streptococcus pneumoniae (9%) were the most common bacterial isolates. On multivariate analysis, history of weight loss (odds ratio [OR] = 2.75; 95% confidence interval [CI] = 1.27–5.95), presence of pulmonary crackles (OR = 3.63; 95% CI = 1.40–9.45), and leukocytosis (OR = 2.21; 95% CI = 1.09–4.47) were independent predictors of bacteremia. At a referral hospital in Uganda, bacteremia was a remarkably common finding in children with febrile illness who were treated for malaria despite negative malaria test results.

Early changes of procalcitonin predict bacteremia in patients with intensive care unit-acquired new fever.

Rapid detection of bacteremia is important for critically ill patients. Procalcitonin (PCT) has emerged as a marker of sepsis, but its characterization for predicting bacteremia is still unclear. This study aimed to investigate the role of change of PCT within 6 to 12 hours after new fever in predicting bacteremia. An observational study was conducted in the ICU of our hospital from January 2009 to March 2010. Adult patients with new fever were included and grouped as bacteremia and non bacteremia group. Serum PCT concentration was measured at admission and within 6 to 12 hours after new fever (designated PCT0 and PCT1). Other results of laboratory tests and therapeutic interventions were recorded. Multivariate Logistic regression analysis was used to identify the risk factors of bacteremia. The area under the ROC curve (AUC) was constructed to evaluate the discriminative power of variables to predict bacteremia. Totally 106 patients were enrolled, 60 of whom had bacteremia and 46 did not have bacteremia,. The acute physiology and chronic health evaluation II (APACHE II) and sequential organ failure assessment (SOFA) scores were 13.1 ± 7.8 and 5.0 ± 2.2 at admission, respectively. There was no significant difference in PCT0 between the bacteremia group and nonbacteremia group; 1.27 µg/L (range, 0.10 - 33.3) vs. 0.98 µg/L (range, 0.08 - 25.7), (P = 0.157). However, the PCT1 and the rate of change of PCT were significantly higher in bacteremia group; PCT1 was 6.73 µg/L (1.13 - 120.10) vs. 1.17 µg/L (0.10 - 12.10) (P = 0.001), and the rate of change was 5.62 times (1.05 - 120.6) vs. 0.07 times (-0.03 - 0.18) (P < 0.001). The area under the ROC curve (AUC; 95% confidence interval) of the rate of change of PCT was better for predicting bacteremia than that of PCT1; 0.864 (range, 0.801 - 0.927) vs. 0.715 (range, 0.628 - 0.801), (P < 0.05). The AUCs of PCT0 and other parameters (such as WBC count, granulocyte percentage and temperature) were not significantly different (all P > 0.05). The best cut-off value for the rate of change was 3.54 times, with a sensitivity of 88.5% and a specificity of 98.0%. It was also an independent predictor of bacteremia (odds ratio 29.7, P < 0.0001) and wasn't correlated with the presence or absence of co-infection, neutropenia or immunodeficiency (P > 0.05). The rate of change of PCT is useful for early detection of bacteremia during new fever and superior to the PCT absolute value and other parameters in non-selected ICU patients.

Predicting Bacteremia among Patients Hospitalized for Skin and Skin-Structure Infections: Derivation and Validation of a Risk Score

Bacteremia is relatively common in patients with skin and skin-structure infection (SSSI) severe enough to require hospitalization. We used selected demographic and clinical characteristics easily assessable at initial evaluation to develop a model for the early identification of patients with SSSI who are at higher risk for bacteremia. A large database of adults hospitalized with SSSI at 97 hospitals in the United States during the period from 2003 through 2007 and from whom blood samples were obtained for culture at admission. We compared selected candidate predictor variables for patients shown to have bacteremia and patients with no demonstrated bacteremia. Using stepwise logistic regression to identify independent risk factors for bacteremia, we derived a model by using 75% of a randomly split cohort, converted the model coefficients into a risk score system, and then we validated it by using the remaining 25% of the cohort. Bacteremia was documented in 1,021 (11.7%) of the 8,747 eligible patients. Independent predictors of bacteremia (P<.001) were infected device or prosthesis, respiratory rate less than 10 or more than 29 breaths per minute, pulse rate less than 49 or more than 125 beats per minute, temperature less than 35.6 degrees C or at least 38.0 degrees C, white blood cell band percentage of 7% or more, white blood cell count greater than 11x10(9)/L, healthcare-associated infection, male sex, and older age. The bacteremia rates ranged from 3.7% (lowest decile) to 30.6% (highest decile) (P<.001). The model C statistic was 0.71; the Hosmer-Lemeshow test P value was .36, indicating excellent model calibration. Using data available at hospital admission, we developed a risk score that differentiated SSSI patients at low risk for bacteremia from patients at high risk. This score may help clinicians identify patients who require more intensive monitoring or antimicrobial regimens appropriate for treating bacteremia.

Bacteremia Increases the Risk of Death among Patients with Soft-Tissue Infections

Soft-tissue infections traditionally have been viewed as carrying a lower risk of death than other types of infection such as pneumonia, blood stream, and intra-abdominal. The influence of secondary bacteremia on the outcomes of patients with soft-tissue infections is not well described. To describe the risk factors for bacteremia among patients admitted to an urban medical center with soft-tissue infections and the influence of bacteremia on outcomes. A retrospective cohort study of 717 patients with culture-positive non-necrotizing soft-tissue infections admitted between April 1, 2005, and December 31, 2007. Bacteremia was present in 52% of the patients. Increasing age, previous hospitalization, decubitus or lower-extremity ulcers, device-related soft-tissue infection, and polymicrobial infection were independent predictors of bacteremia. Intensive care unit admission (adjusted odds ratio [AOR] 3.57; 95% confidence interval [CI] 2.17, 5.86), lower-extremity ulcer (AOR 3.43; 95% CI 2.07, 5.70), and bacteremia (AOR 6.37; 95% CI 3.34, 12.12) were independent predictors of in-hospital death. When patients with device-related soft-tissue infections were excluded, the rate of secondary bacteremia was 37.6% (201/535), and it remained an independent predictor of in-hospital death. The occurrence of bacteremia in soft-tissue infections is associated with a greater risk of death. Health care providers should be aware of the risk factors for bacteremia in patients with soft-tissue infections in order to provide more appropriate initial antimicrobial therapy and to ascertain its presence as a prognostic indicator.

Effect of Diabetes Mellitus on the Clinical and Microbiological Features of Hospitalized Elderly Patients with Acute Pyelonephritis

To study potential differences in the clinical and microbiological features of hospitalized elderly patients with acute pyelonephritis with and without diabetes mellitus. Retrospective review of medical records. University hospital. Eighty-eight patients aged 65 and older with diabetes mellitus (DM) (57 female; 64.8%) and 118 controls without DM (75 female; 63.6%), matched for age and sex, hospitalized with acute pyelonephritis between January 1997 and December 2005. Medical records were reviewed for demographic, clinical, and microbiological characteristics. The median age of both groups was 74 (range 65-95). Twenty-seven people with DM (30.7%) and 13 controls (11.0%) had bacteremia (P=.001). People with DM had longer fever (median 4.5 vs 2.5 days; P<.001), longer hospitalization (median 10 vs 7 days; P<.001), and greater mortality (12.5% vs 2.5%; P<.01) than controls. Logistic regression analysis proved DM to be an independent predictor of bacteremia, long hospitalization, and mortality. Escherichia coli was the most common microorganism found in both groups, whereas Candida spp. were implicated more frequently in people with DM than controls (12.7% vs 1.7%; P<.01). Antimicrobial resistance did not increase over the study period. Acute pyelonephritis in elderly people with DM is associated with risk of bacteremia, long hospitalization, and mortality.

The Clinical Impact of Ganciclovir Prophylaxis on the Occurrence of Bacteremia in Orthotopic Liver Transplant Recipients

Cytomegalovirus (CMV) infection or receipt of a CMV-seropositive donor liver has been shown to be an independent predictor of bacteremia in orthotopic liver transplant (OLT) recipients. However, prevention of CMV infection through use of intense CMV prophylaxis has not been examined to assess the impact on bacteremia in liver transplant recipients. We analyzed the impact of CMV prophylaxis on rates of bacteremia by examining 192 consecutive OLT recipients during a 2-year follow-up period. There were 29 episodes of bacteremia. Univariate analysis of risk factors for bacteremia showed that invasive fungal disease, initial anti-lymphocyte immunosuppression, treatment for rejection, and use of solumedrol were significantly associated with increased risk. Receipt of >or=14 days of ganciclovir prophylaxis (hazard ratio [HR], 0.40; 95% CI [confidence interval], 0.18-0.87; P=.02), end-to-end biliary anastomosis, and receipt of <10 units of red blood cells (RBCs) were significantly associated with a decreased risk. Three-variable analysis controlling for end-to-end anastomosis and use of <10 units of RBCs, showed that use of >or=14 days of ganciclovir was still associated with a reduced risk of bacteremia (HR, 0.44; 95% CI, 0.20-0.98; P=.0437). Among factors associated with bacteremia, use of prophylactic ganciclovir is independently associated with a significant reduction of bacteremia in OLT recipients.

Bacteriemia adquirida en la comunidad: elaboración de un modelo de predicción clínica en pacientes ingresados en un servicio de medicina interna

Clinical suspicion of bacteremia lacks of sensitivity, specificity or predictive values enough to be clinically useful. The aim of this study was to develop a clinical prediction rule of bacteremia for patients hospitalized in an internal medicine department, with community-acquired symptoms, who had blood cultures obtained. A prospective study, including all patients who had blood cultures in the first 48 h after admission, was performed. A clinical prediction rule of bacteremia was derived from a random sample of two thirds of the patients (derivation cohort) and validated in the remaining (validation cohort). After bivariate analysis, significant variables were included in a stepwise logistic regression analysis. In every patient out of the derivation and validation cohorts a score, derived from the addition of points for each of the significant predictor variables of logistic regression, was obtained; according to this score, 4 groups were formed, and the prevalence of bacteremia in each of them was calculated. Calibration and discrimination were evaluated by the Hosmer-Lemeshow test and area under the ROC curve respectively. Four hundred and forty-eight blood cultures were obtained; the prevalence of bacteremia was 25.2%. Independent predictors of bacteremia in the bivariate analysis were urinary focus of infection, body temperature >= 38.3 degrees C, presence of band forms, ESR >= 70 mm, platelets < 200 * 103/microl, blood glucose >= 140 mg/dl, urea >= 50 mg/dl, C-reactive protein >= 12 mg/dl, and albumin < 3 g/dl. According to the score, in the derivation cohort, four groups with increasing prevalence of bacteremia were identified; in the group with a score between 0 and 3, the prevalence was 2.4%; between 4 and 5: 15.7%; between 6 and 7: 42.9%; and score >= 8: 65%. In the validation cohort, the prevalence was 4.1%, 22.6%, 29.3%, and 80%, respectively. The model showed good calibration (Hosmer-Lemeshow *2 = 4.91; p = 0.77). Area under the ROC curve was 0.81 (95% confidence interval, 0.76-0.86) in the derivation cohort, and 0.77 (95% confidence interval, 0.69-0.85) in validation cohort. Our model, constructed with 9 variables and a simple additive point system, had good calibration and discrimination, which points at its usefulness to estimate the probability of bacteremia in patients admitted in an Internal Medicine department. Used in conjunction with clinical judgement, the model can be useful in the decision-making process, concerning blood cultures obtention, clinical monitoring, and empirical antimicrobial therapy. Before application, additional prospective validation in other settings is warranted.

Difficulty in predicting bacteremia in elderly emergency patients

To characterize the clinical presentation and identify factors predictive of bacteremia in elderly patients. Retrospective review of emergency department charts, hospital records, and microbiology reports. Community teaching hospital with annual ED census of 65,000 adults. Seven hundred fifty elderly patients (aged 65 to 99 years) who were evaluated by the emergency physician, had blood cultures obtained in the ED, and were hospitalized with a suspected infectious process during a 12-month period. Records were analyzed for demographic information, underlying diseases, clinical presentation, laboratory findings, sources of infection, and causative organisms. Using contingency tables, 79 patients with positive blood cultures were compared with a random sample of 136 patients with sterile blood cultures to identify clinical variables significantly (P less than .05) associated with bacteremia. Logistic regression analysis was performed with significant factors to develop a model to predict bacteremia. Sensitivity, specificity, and predictive values were calculated for the model. The prevalence of bacteremia was 10.6%. Escherichia coli was the most commonly isolated pathogen (29% of cases), and the urinary tract was the most common source of infection (44.3% of cases). Logistic regression analysis showed that altered mental status (odds ratio, 2.88; 95% confidence interval [Cl], 1.52 to 5.50), vomiting (odds ratio, 2.63; 95% Cl, 1.16 to 6.15), and WBC band forms of more than 6% (0.06) (odds ratio, 3.50; 95% Cl, 1.58 to 5.27) were independent predictors of bacteremia. The presence of at least one of these three factors had a sensitivity of 0.85 (95% Cl, 0.75 to 0.92) and a specificity of 0.46 (95% Cl, 0.38 to 0.55) for predicting bacteremia in the study group. The positive predictive value was 0.16 (95% Cl, 0.12 to 0.19) and the negative predictive value was 0.96 (95% Cl, 0.94 to 0.98) for the ED patient group that met inclusion criteria. Elderly patients fail to manifest identifiable clinical features indicative of bloodstream infection. The sensitivity and specificity of the best statistical model for identifying bacteremic elderly patients suggest that clinical indicators alone are unreliable predictors of bacteremia in the geriatric ED population studied.