Infección del sitio de salida de los catéteres venosos centrales y su asociación con bacteriemia relacionada con catéter / Infection of the exit site central venous catheters and its association with bacteremia related to catheter

Introducción: Los catéteres venosos centrales (CVC) plantean un alto riesgo de infección. La infección del sitio de salida (ISS-CVC) es la menos estudiada, y se desconoce su asociación con la bacteriemia asociada a catéter (BAC) y su impacto en la evolución del paciente. Objetivo: Evaluar la asociación entre ISS-CVC, BAC y mortalidad. Materiales y métodos: Estudio prospectivo, de observación. Pacientes internados en una Unidad de Terapia Intensiva médico/quirúrgica que requirieron la colocación de CVC desde el 01/06/2010 hasta el 01/04/2012. Se evaluaron datos epidemiológicos, BAC (según criterios de los CDC) y gérmenes. Se utilizaron media ± DE, mediana y rango intercuartílico, y porcentajes. Resultados: Durante este período, ingresaron 575 pacientes, el 98% requirió CVC. Datos de los pacientes: edad 41 ± 26 años, APACHE II 15 ± 7, 96% con ventilación mecánica, días de ventilación mecánica 41 (33-63), días de internación 43 (25-67). Todos los CVC con ISS fueron retirados y cultivados. Se observaron 51 ISS: 5,5/1000-días-catéter: 33% subclavia, 38% yugular, 29% femoral. Seis pacientes con ISS (12%) tuvieron BAC (0,65/1000-días-catéter): 3 subclavias, 2 yugulares, 1 femoral; 2 con halo y 8 con secreción purulenta. Tiempo de permanencia del CVC: 7,5 días (5-10). Clínica al momento de la ISS: shock 50%, fiebre 83%, SOFA 6 ± 3. El 83% de las infecciones fueron monomicrobianas: 83% por bacilos gramnegativos (2 Klebsiella, 2 Pseudomonas, 1 Serratia y 1 Acinetobacter), 17% por enterococos resistentes a vancomicina. La mortalidad fue del 50%. Conclusión: Aunque la ISS provocó una baja incidencia de BAC, la mortalidad fue alta. Al parecer, la ISS no es un factor predictivo de BAC.(AU)

Introduction: Central venous catheters (CVC) are widely used and pose a high risk of infection. There are few studies on insertion site infection (ISI-CVC), and both its association with catheter-associated bloodstream infection (CABSI) and the outcome of patients are unknown. Objective: To determine the association between ISI-CVC, the presence of CABSI and mortality. Materials and methods: Prospective observational study. All patients admitted to a medical/surgical Intensive Care Unit requiring CVC insertion from 06/01/2010 to 04/01/2012 were included. Epidemiological data, CABSI (according to CDC criteria) and microorganisms involved were evaluated. Mean ± SD, median and interquartile range, and percentages were used. Results: During the period study, 575 patients were admitted, 98% required CVC. Patient´s data: age 41 ± 26 years, APACHE II 15 ± 7, 96% on mechanical ventilation, days on mechanical ventilation: 41 (33-63), length of stay 43 (25-67) days. All CVCs with ISI were removed and cultured. Fifty one ISI were observed (5.5/1000-catheter-day). Six patients with ISI (12%) presented CABSI (0.65/1000-catheter-day): 3 in subclavian, 2 in jugular, 1 femoral; 2 with erythema and 8 with purulent secretion. CVC permanence: 7.5 day (5-10). Signs and/or symptoms at the moment of ISI: shock 50%, fever 83%, SOFA 6 ± 3. The 83% of infections were caused by one microorganism: 83% due to gram-negative bacilli (2 Klebsiella, 2 Pseudomonas, 1 Serratia, and 1 Acinetobacter), 17% due to vancomycin-resistant enterococci. The mortality rate was 50%. Conclusion: Although ISI-CVC presented a low incidence of CABSI, mortality rate was high. The ISI-CVC might have a little predictable value for CABSI.(AU)

Evaluation of red blood cell aggregation in diabetes by computerized image analysis

Red blood cell (RBC) aggregation has been widely studied and its importance is well established in the rheology of microcirculation. RBC aggregation is a major factor responsible for the flow properties of blood. Increased RBC aggregation has been observed in several pathological states. Therefore, the measurement of erythrocyte aggregation is rheologically important for quantifying flow abnormality in pathological conditions. Normal RBC under low flow or at rest form rouleaux aggregates, while abnormal RBC aggregation may lead to the formation of irregular aggregate structures, which may be induced by cell-associated factors (reduced membrane sialic acid levels) but also by extracellular factors. The main objective of the present investigation was to study RBC aggregate morphology in diabetic patients, using direct microscopic observation and numerical processing of recorded digitized images. Blood samples were obtained from 20 diabetic patients and from 15 normal control subjects. The aggregate morphology was quantified by the so-called Aggregate Shape Parameter (ASP) defined as the ratio of the aggregate projected area to its square perimeter. ASP appeared significantly higher (p < 10(-5)) in diabetic patients (0.65 +/- 0.18) than in normal controls (0.28 +/- 0.15). This rheo-optical method based on the theoretical model for rouleaux aggregates provides a useful reference for measuring deviations of RBC aggregate morphology. Increased aggregation of RBC resulting from a decreased sialylation of glycophorins may be an important factor in the development of vascular diseases and in the microcirculation impairment.

Anticuerpos anti-beta, glicoproteína I y niveles plasmáticos de la proteína de unión a C4b / Antibodies against beta glycoprotein I and C4b binding protein plasmatic levels

Autoantibodies directed to beta2 glycoprotein I (a beta 2 GPI) are frequently found in patients with antiphospholipid antibodies (aPL). They are more strongly associated with clinical manifestations of the antiphospholipid syndrome then a PL. It has been shown that beta2 GPI and C4b bibding protein (C4bBP) share certain homology. In a previous study we have shown that anticardiolipin antibodies were associated with a plasma decrease of C4bBP. The aim of the present study was to evaluate in 131 patients with a PL whether the decrease in C4bBP is related to the presence of abeta2 GPI. Lower C4bBP levels (mean +- SD) in the group of patients having abeta2 GPI (n=57) were observed when compared with the normal group (n=44), (74.3 porciento +-28.1 vs 94.6 porciento +-20.9,p<0.005).This difference was more significant consideing the IgG isotype. The group of patients with positive abeta2GPI-igG (n=41) had lower values of C4bBP (70.1 porciento +- 26.8) than both the normal group (p<0.005) and the group of patients with negative abeta2 IgG (n=90, 86.0 porciento +- 30.5 porciento, p<0.05). C4bBP deficiency (level <70 porciento) was also morefrequent in the group abeta 2GPI-IgG (+) (63.4 porciento) then in the group abeta2GPI-IgG 8-) (34.4 porciento, p<0.005). Moreover, patients with a PL and previews venous thrombosis (n=32) showed lower C4bBP values (75.1 porciento +- 27.9) compared with the normal group (p<0.05). As this time, the mechanisms responsibles for the C4bBP decrease are not known. Our findings on the close relationship between abnormalitiesin the C4bBP/protein S system and the presence of abeta2GPI could explain the major thrombotic risk in patients havingthese autoantibodies