A latent class approach for sepsis diagnosis supports use of procalcitonin in the emergency room for diagnosis of severe sepsis.

BACKGROUND: Given the acknowledged problems in sepsis diagnosis, we use a novel way with the application of the latent class analysis (LCA) to determine the operative characteristics of C-reactive protein (CRP), D-dimer (DD) and Procalcitonin (PCT) as diagnostic tests for sepsis in patients admitted to hospital care with a presumptive infection. METHODS: Cross-sectional study to determine the diagnostic accuracy of three biological markers against the gold standard of clinical definition of sepsis provided by an expert committee, and also against the likelihood of sepsis according to LCA. Patients were recruited in the emergency room within 24 hours of hospitalization and were follow-up daily until discharge. RESULTS: Among 765 patients, the expert committee classified 505 patients (66%) with sepsis, 112 (15%) with infection but without sepsis and 148 (19%) without infection. The best cut-offs points for CRP, DD, and PCT were 7.8 mg/dl, 1616 ng/ml and 0.3 ng/ml, respectively; but, neither sensitivity nor specificity reach 70% for any biomarker. The LCA analysis with the same three tests identified a "cluster" of 187 patients with several characteristics suggesting a more severe condition as well as better microbiological confirmation. Assuming this subset of patients as the new prevalence of sepsis, the ROC curve analysis identified new cut-off points for the tests and suggesting a better discriminatory ability for PCT with a value of 2 ng/ml. CONCLUSIONS: Under a "classical" definition of sepsis three typical biomarkers (CRP, PCT and DD) are not capable enough to differentiate septic from non-septic patients in the ER. However, a higher level of PCT discriminates a selected group of patients with severe sepsis.

D-dimer is a significant prognostic factor in patients with suspected infection and sepsis.

PURPOSE: The aim of the study was to determine whether C-reactive protein (CRP), procalcitonin (PCT), and d-dimer (DD) are markers of mortality in patients admitted to the emergency department (ED) with suspected infection and sepsis. BASIC PROCEDURES: We conducted a prospective cohort in a university hospital in Medellín, Colombia. Patients were admitted between August 1, 2007, and January 30, 2009. Clinical and demographic data and Acute Physiology and Chronic Health Evaluation II and Sepsis Organ Failure Assessment scores as well as blood samples for CRP, PCT, and DD were collected within the first 24 hours of admission. Survival was determined on day 28 to establish its association with the proposed biomarkers using logistic regression and receiver operating characteristic curves. MAIN FINDINGS: We analyzed 684 patients. The median Acute Physiology and Chronic Health Evaluation II and Sepsis Organ Failure Assessment scores were 10 (interquartile range [IQR], 6-15) and 2 (IQR, 1-4), respectively. The median CRP was 9.6 mg/dL (IQR, 3.5-20.4 mg/dL); PCT, 0.36 ng/mL (IQR, 0.1-3.7 ng/mL); and DD, 1612 ng/mL (IQR, 986-2801 ng/mL). The median DD in survivors was 1475 ng/mL (IQR, 955-2627 ng/mL) vs 2489 ng/mL (IQR, 1698-4573 ng/mL) in nonsurvivors (P=.0001). The discriminatory ability showed area under the curve-receiver operating characteristic for DD, 0.68; CRP, 0.55; and PCT, 0.59. After multivariate analysis, the only biomarker with a linear relation with mortality was DD, with an odds ratio of 2.07 (95% confidence interval, 0.93-4.62) for values more than 1180 and less than 2409 ng/mL and an odds ratio of 3.03 (95% confidence interval, 1.38-6.62) for values more than 2409 ng/mL. PRINCIPAL CONCLUSIONS: Our results suggest that high levels of DD are associated with 28-day mortality in patients with infection or sepsis identified in the emergency department.

Diagnostic accuracy of HMGB-1, sTREM-1, and CD64 as markers of sepsis in patients recently admitted to the emergency department.

OBJECTIVES: The objectives were to evaluate the diagnostic accuracy for sepsis in an emergency department (ED) population of the cluster of differentiation-64 (CD64) glycoprotein expression on the surface of neutrophils (nCD64), serum levels of soluble triggering receptor expressed on myeloid cells-1 (s-TREM-1), and high-mobility group box-1 protein (HMGB-1). METHODS: Patients with any of the following as admission diagnosis were enrolled: 1) suspected infection, 2) fever, 3) delirium, or 4) acute hypotension of unexplained origin within 24 hours of ED presentation. Levels of nCD64, HMGB-1, and s-TREM-1 were measured within the first 24 hours of the first ED evaluation. Baseline clinical data, Sepsis-related Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation (APACHE II) score, daily clinical and microbiologic information, and 28-day mortality rate were collected. Because there is not a definitive criterion standard for sepsis, the authors used expert consensus based on clinical, microbiologic, laboratory, and radiologic data collected for each patient during the first 7 days of hospitalization. This expert consensus defined the primary outcome of sepsis, and the primary data analysis was based in the comparison of sepsis versus nonsepsis patients. The cut points to define sensitivity and specificity values, as well as positive and negative likelihood ratios (LRs) for the markers related to sepsis diagnosis, were determined using receiver operative characteristics (ROC) curves. The patients in this study were a prespecified nested subsample population of a larger study. RESULTS: Of 631 patients included in the study, 66% (95% confidence interval [CI] = 62% to 67%, n = 416) had sepsis according with the expert consensus diagnosis. Among these sepsis patients, SOFA score defined 67% (95% CI = 62% to 71%, n = 277) in severe sepsis and 1% (95% CI = 0.3% to 3%, n = 6) in septic shock. The sensitivities for sepsis diagnosis were CD64, 65.8% (95% CI = 61.1% to 70.3%); HMGB-1, 57.5% (95% CI = 52.7% to 62.3%); and s-TREM-1, 60% (95% CI = 55.2% to 64.7%). The specificities were CD64, 64.6% (95% CI = 57.8% to 70.8%), HMGB-1, 57.8% (95% CI = 51.1% to 64.3%), and s-TREM-1, 59.2% (95% CI = 52.5% to 65.6%). The positive LR (LR+) for CD64 was 1.85 (95% CI = 1.52 to 2.26) and the negative LR (LR-) was 0.52 (95% CI = 0.44 to 0.62]; for HMGB-1 the LR+ was 1.36 (95% CI = 1.14 to 1.63) and LR- was 0.73 (95% CI = 0.62 to 0.86); and for s-TREM-1 the LR+ was 1.47 (95% CI = 1.22 to 1.76) and the LR- was 0.67 (95% CI = 0.57 to 0.79). CONCLUSIONS: In this cohort of patients suspected of having any infection in the ED, the accuracy of nCD64, s-TREM-1, and HMGB-1 was not significantly sensitive or specific for diagnosis of sepsis.

Toward an operative diagnosis in sepsis: a latent class approach.

BACKGROUND: Recent data have suggested that 18 million of new sepsis cases occur each year worldwide, with a mortality rate of almost 30%. There is not consensus on the clinical definition of sepsis and, because of lack of training or simply unawareness, clinicians often miss or delay this diagnosis. This is especially worrying; since there is strong evidence supporting that early treatment is associated with greater clinical success. There are some difficulties for sepsis diagnosis such as the lack of an appropriate gold standard to identify this clinical condition. This situation has hampered the assessment of the accuracy of clinical signs and biomarkers to diagnose sepsis. METHODS/DESIGN: Cross-sectional study to determine the operative characteristics of three biological markers of inflammation and coagulation (D-dimer, C-reactive protein and Procalcitonin) as diagnostic tests for sepsis, in patients admitted to hospital care with a presumptive infection as main diagnosis. DISCUSSION: There are alternative techniques that have been used to assess the accuracy of tests without gold standards, and they have been widely used in clinical disciplines such as psychiatry, even though they have not been tested in sepsis diagnosis. Considering the main importance of diagnosis as early as possible, we propose a latent class analysis to evaluate the accuracy of three biomarkers to diagnose sepsis.

Infección nosocomial por enterococo resistente a la vancomicina: características clínico-epidemiológicas y factores de riesgo / Nosocomial infection by Vancomicin resistant Enterococcus: Clinical - epidemiological characteristics and risk factors

Objetivo: caracterizar clínica y epidemiológicamente, y establecer los factores de riesgo de un brote de infección nosocomial por Enterococcus faecium resistente a vancomicina en el HUSVP de Medellín. Metodología: se realizó un estudio con una fase descriptiva (27 casos) y un diseño tipo casos (27) y controles (54). Resultados: los 27 casos de E. faecium tuvieron un alto nivel de resistencia a vancomicina (128 ug/ml), y además fueron resitentes a teicoplanina, ampicilina, penicilina, ciprofloxacina, y gentamicina y estreptomicina de alto nivel. En el 67 por ciento de los casos se interpretó cono infección; el 33 por ciento de las cepas se aislaron de orina y el 22 por ciento de cavidad abdominal. Los factores de riesgo asociados fueron la insuficiencia renal (RD 12.6), nutrición parenteral total (RD 6.2), la cirugía abdominal (RD 4.1), uso previo de metronidazol (RD 19.5) ceftazidima (RD 15.9), cefotaxima (RD 12.6), imipenem (RD 11.6), ciproflaxina (RD 6.7), vancomicina (RD 5.4), ampicilina/sulbactam (RD 4.4), días estancia (p=0.004), días entre el ingreso y la infección (p=0.0007), número de cirugias (p=0.0004) y número de antibióticos previos (p=0.00005). Conclusiones: esta es la primera epidemia de ERV que se publica en Colombia, con un análisis clínico, epidemiológico y de factores de riesgo, y nos muestra una realidad ya vivida por otros países y de muy difícil manejo, y nos alerta sobre la posibilidad de aparición de Staphylococcus aureus con sensibilidad disminuida a la vancomicina