Infections in critically ill burn patients.

Severe burn patients are one subset of critically patients in which the burn injury increases the risk of infection, systemic inflammatory response and sepsis. The infections are usually related to devices and to the burn wound. Most infections, as in other critically ill patients, are preceded by colonization of the digestive tract and the preventative measures include selective digestive decontamination and hygienic measures. Early excision of deep burn wound and appropriate use of topical antimicrobials and dressings are considered of paramount importance in the treatment of burns. Severe burn patients usually have some level of systemic inflammation. The difficulty to differentiate inflammation from sepsis is relevant since therapy differs between patients with and those without sepsis. The delay in prescribing antimicrobials increases morbidity and mortality. Moreover, the widespread use of antibiotics for all such patients is likely to increase antibiotic resistance, and costs. Unfortunately the clinical usefulness of biomarkers for differential diagnosis between inflammation and sepsis has not been yet properly evaluated. Severe burn injury induces physiological response that significantly alters drug pharmacokinetics and pharmacodynamics. These alterations impact antimicrobials distribution and excretion. Nevertheless the current available literature shows that there is a paucity of information to support routine dose recommendations.

Factors associated with severity in invasive community-acquired Staphylococcus aureus infections in children: a prospective European multicentre study.

Staphylococcus aureus is the main pathogen responsible for bone and joint infections worldwide and is also capable of causing pneumonia and other invasive severe diseases. Panton-Valentine leukocidin (PVL) and methicillin-resistant S. aureus (MRSA) have been studied as factors related with severity in these infections. The aims of this study were to describe invasive community-acquired S. aureus (CA-SA) infections and to analyse factors related to severity of disease. Paediatric patients (aged 0-16 years) who had a CA-SA invasive infection were prospectively recruited from 13 centres in 7 European countries. Demographic, clinical and microbiological data were collected. Severe infection was defined as invasive infection leading to death or admission to intensive care due to haemodynamic instability or respiratory failure. A total of 152 children (88 boys) were included. The median age was 7.2 years (interquartile range, 1.3-11.9). Twenty-six (17%) of the 152 patients had a severe infection, including 3 deaths (2%). Prevalence of PVL-positive CA-SA infections was 18.6%, and 7.8% of the isolates were MRSA. The multivariate analysis identified pneumonia (adjusted odds ratio (aOR) 13.39 (95% confidence interval (CI) 4.11-43.56); p 0.008), leukopenia at admission (<3000/mm(3)) (aOR 18.3 (95% CI 1.3-259.9); p 0.03) and PVL-positive infections (aOR 4.69 (95% CI 1.39-15.81); p 0.01) as the only factors independently associated with severe outcome. There were no differences in MRSA prevalence between severe and nonsevere cases (aOR 4.30 (95% CI 0.68- 28.95); p 0.13). Our results show that in European children, PVL is associated with more severe infections, regardless of methicillin resistance.

Concurrent interspecies and clonal dissemination of OXA-48 carbapenemase.

Several isolates of four different carbapenemase-producing Enterobacteriaceae species were recovered from a patient hospitalized for 4 months in a teaching hospital in Madrid. These species comprised seven Klebsiella pneumoniae belonging to ST15, four Escherichia coli belonging to ST2531, two Serratia marcescens and one Citrobacter freundii. This patient was the index case of a small outbreak of four patients infected and/or colonized by carbapenemase-producing K. pneumoniae. Molecular results identified the bla(OXA-48) gene in all Enterobacteriaceae isolates from the index case and in all isolates from the other three patients, suggesting intra- and interpatient dissemination. Our results highlight the great ability of OXA-48 carbapenemase to spread among different enterobacterial species by both clonal and nonclonal dissemination.

Pneumonia in patients with severe burns : a classification according to the concept of the carrier state.

OBJECTIVE: To establish baseline values of pneumonia incidence and mortality and to distinguish primary endogenous from secondary endogenous and exogenous pneumonias in a homogeneous patient population with severe burns. DESIGN: Cohort study. SETTING: A six-bed burn ICU. PATIENTS: All patients of > or = 14 years admitted to the ICU between January 1995 and June 1996 with a total body surface area burn of > or = 20%. INTERVENTION: Collection of data on surveillance samples from throat and rectum on admission and twice weekly afterward, and pneumonias during the ICU stay. MEASUREMENTS AND RESULTS: Fifty-six patients fulfilled the criteria of the study. Mean age was 43 +/- 19.8 years; total body surface area burn, 41 +/- 18.2%; the area of full-thickness burn was 24 +/- 17.7%. Forty-one patients required mechanical ventilation. Twenty-seven patients (48%) experienced 37 episodes of pneumonia. Twenty-one pneumonias were of primary endogenous development, ie, caused by potential pathogens carried in the admission flora. There were 14 secondary endogenous and 2 exogenous infections caused by microorganisms acquired on the burn unit. Inhalation injury was identified in 26 patients. The pneumonia rate was two times higher in the subset of patients with inhalation injury compared with the group of patients without inhalation injury (p < 0.001). Overall mortality was 25%. CONCLUSIONS: This study shows that pneumonia in burn patients is mainly an endogenous problem. Interventions that prevent the development of endogenous infections deserve prospective evaluation in patients with severe burns.

Effectiveness and safety of enteral vancomycin to control endemicity of methicillin-resistant Staphylococcus aureus in a medical/surgical intensive care unit.

A prospective trial was undertaken to assess the effectiveness and safety of enteral vancomycin in controlling methicillin-resistant Staphylococcus aureus (MRSA) in an endemic setting. Over the 49 month period patients aged >14 years were enrolled, following admission to a medical/surgical intensive care unit (ICU) and expected to require ventilation for three days or more. A total of 799 patients were included in the trial. Period one, 1 July 1996-30 April 1997, (N=140), was observational. During period two, 1 May 1997-30 September 1998, (N=258), surveillance samples were obtained. MRSA carriers were isolated and received enteral vancomycin. During period three, 1 October 1998-31 July 2000, (N=400), all ventilated patients were given selective digestive decontamination (SDD) with polymyxin E, tobramycin, amphotericin B and vancomycin and four days of intravenous cefotaxime. The primary endpoints were: (1) incidence of patients with diagnostic samples positive for MRSA acquired on the ICU; (2) incidence of patients with vancomycin-resistant enterococci (VRE) in surveillance or diagnostic samples; (3) incidence of patients with samples positive for S. aureus with intermediate sensitivity to glycopeptides (GISA). The incidence of patients with MRSA in diagnostic samples were 31%, 14%, and 2% in periods one, two and three, respectively (P<0.001). There was a VRE outbreak involving 13 patients during period three. VRE disappeared with no change in policy. GISA was not detected. These findings support the effectiveness and safety of enteral vancomycin in the control of MRSA.

Infections in critically ill burn patients / Infecciones en los enfermos quemados críticos

Severe burn patients are one subset of critically patients in which the burn injury increases the risk of infection, systemic inflammatory response and sepsis. The infections are usually related to devices and to the burn wound. Most infections, as in other critically ill patients, are preceded by colonization of the digestive tract and the preventative measures include selective digestive decontamination and hygienic measures. Early excision of deep burn wound and appropriate use of topical antimicrobials and dressings are considered of paramount importance in the treatment of burns. Severe burn patients usually have some level of systemic inflammation. The difficulty to differentiate inflammation from sepsis is relevant since therapy differs between patients with and those without sepsis. The delay in prescribing antimicrobials increases morbidity and mortality. Moreover, the widespread use of antibiotics for all such patients is likely to increase antibiotic resistance, and costs. Unfortunately the clinical usefulness of biomarkers for differential diagnosis between inflammation and sepsis has not been yet properly evaluated. Severe burn injury induces physiological response that significantly alters drug pharmacokinetics and pharmacodynamics. These alterations impact antimicrobials distribution and excretion. Nevertheless the current available literature shows that there is a paucity of information to support routine dose recommendations

Los pacientes con quemaduras graves son un subgrupo de pacientes críticos en los que la lesión por quemadura aumenta el riesgo de infección, de respuesta inflamatoria sistémica y de sepsis. Las infecciones suelen estar relacionadas con los dispositivos y la quemadura. La mayoría de las infecciones, al igual que en otros pacientes críticos, están precedidas por la colonización del tracto digestivo y de medidas preventivas que incluyen la descontaminación digestiva selectiva y las medidas de higiene. La escisión precoz de las quemaduras profundas y el uso adecuado de los antimicrobianos tópicos y apósitos se consideran de suma importancia en el tratamiento de las quemaduras. Los pacientes con quemaduras graves suelen tener un cierto nivel de inflamación sistémica. La dificultad para diferenciar inflamación de sepsis es relevante debido a que la terapia difiere entre los pacientes con y sin sepsis. El retraso en la prescripción de antimicrobianos aumenta la morbimortalidad. Además, el uso generalizado de antibióticos en todos estos pacientes es probable que aumente la resistencia a estos y los costes. Desafortunadamente, la utilidad clínica de biomarcadores para el diagnóstico diferencial entre inflamación y sepsis aún no ha sido adecuadamente evaluada. La lesión por quemadura severa induce una respuesta fisiológica que altera significativamente la farmacocinética y farmacodinámica de los fármacos. Estas alteraciones afectan a la distribución y excreción de los antimicrobianos. Sin embargo, la literatura disponible actual muestra que hay una escasez de información para apoyar las recomendaciones de dosis rutinarias

Utilización y rendimiento de los hemocultivos en una unidad de cuidados intensivos medicoquirúrgica / Utilization and utility of blood cultures in a medical-surgical intensive care unit

Objetivo. Estimar la utilización y el rendimiento de los hemocultivos en una unidad de cuidados intensivos (UCI) medicoquirúrgica y evaluar los factores que pueden influir en su rendimiento.Diseño. Estudio prospectivo de cohortes.Ámbito. Unidad de cuidados intensivos medicoquirúrgica de hospital de tercer nivel.Intervenciones. Ninguna.Variables de interés. Tasas de incidencia acumulada de extracción de hemocultivos, porcentaje de hemocultivos positivos y factores asociados a la obtención de un hemocultivo positivo.Resultados. En los 2 períodos de estudio se extrajeron 953 hemocultivos en los 2.663 pacientes que ingresaron en la UCI. Se extrajeron a los 10 (15) días (mediana, 5 días; P25, 1; P75, 13) desde el ingreso en la UCI. La tasa de incidencia acumulada obtenida fue de 36 hemocultivos por 100 pacientes y de 55 hemocultivos por 1.000 pacientes/día. Los hemocultivos positivos fueron 155 (16 por ciento; intervalo de confianza [IC] del 95 por ciento, 1419), los hemocultivos contaminados fueron 57 (6 por ciento; IC del 95 por ciento, 5-8) y los indeterminados 22 (2 por ciento; IC del 95 por ciento, 1-3). Los factores asociados a obtener un hemocultivo positivo fueron: no estar recibiendo antibióticos (odds ratio [OR], 2,16), ni descontaminación digestiva selectiva (OR, 1,52) en el momento de extraer el hemocultivo y si el hemocultivo se obtiene cuando el paciente lleva ingresado en la UCI más de 2 semanas (OR, 2,65).Conclusiones. En nuestro estudio la tasa de extracción de hemocultivos fue menor a la descrita en enfermos críticos. El rendimiento de los hemocultivos se asoció con la administración de antibióticos sistémicos y tópicos y con el momento de su extracción (AU)