Ventilator-associated pneumonia caused by multidrug-resistant organisms or Pseudomonas aeruginosa: prevalence, incidence, risk factors, and outcomes

PURPOSE: The aim of this study was to clarify the prevalence and incidence of, risk factors for, and outcomes from suspected ventilator-associated pneumonia (VAP) associated with the isolation of either Pseudomonas or multidrug-resistant (MDR) bacteria ("high risk" pathogens) from respiratory secretions. MATERIALS AND METHODS: Data were collected as part of a large, multicentered trial of diagnostic and therapeutic strategies for patients (n = 739) with suspected VAP. RESULTS: At enrollment, 6.4% of patients had Pseudomonas species, and 5.1% of patients had at least 1 MDR organism isolated from respiratory secretions. Over the study period, the incidence of Pseudomonas and MDR organisms was 13.4% and 9.2%, respectively. Independent risk factors for the presence of these pathogens at enrollment were duration of hospital stay >or=48 hours before intensive care unit (ICU) admission (odds ratio, 2.37 [95% CI, 1.40-4.02]; P = .001] and prolonged duration of ICU stay before enrollment (odds ratio, 1.50 [95% CI, 1.17-1.93]; P = .002] per week. Fewer patients whose specimens grew either Pseudomonas or MDR organisms received appropriate empirical antibiotic therapy compared to those without these pathogens (68.5% vs 93.9%, P < .001). The isolation of high risk pathogens from respiratory secretions was associated with higher 28-day (relative risk, 1.59 [95% CI, 1.07-2.37]; P = .04] and hospital mortality (relative risk, 1.48 [95% CI, 1.05-2.07]; P = .05), and longer median duration of mechanical ventilation (12.6 vs 8.7 days, P = .05), ICU length of stay (16.2 vs 12.0 days, P = .05), and hospital length of stay (55.0 vs 41.8 days, P = .05). CONCLUSIONS: In this patient population, the incidence of high-risk organisms newly acquired during an ICU stay is low. However, the presence of high risk pathogens is associated with worse clinical outcomes.     

Correlates of clinical failure in ventilator-associated pneumonia: insights from a large, randomized trial

PURPOSE: Our objective was to determine clinical variables measured at baseline and day 3 that may relate to failure of resolution of ventilator-associated pneumonia (VAP). MATERIALS AND METHODS: In patients with confirmed VAP derived from a large, randomized controlled trial comparing different modalities for the diagnosis and treatment of VAP, we identified risk factors associated with clinical failure. Clinical failure was prospectively defined in this trial as death, persistence of clinical and radiographic features of infection throughout the study period requiring additional antibiotics, superinfection, or relapsing infection. We examined the relationship between VAP resolution and clinical characteristics measured both at study enrollment and at day 3. We used logistic regression to identify independent factors associated with clinical failure and conducted a sensitivity analysis focusing only on patients who met the definition for clinical failure but who nonetheless survived until day 28. RESULTS: Of 563 subjects with VAP, 179 (31.8%) were classified as clinical failures. Death was the most common reason for clinical failure. At baseline, clinical failure patients were older, more severely ill, had been on mechanical ventilation for a longer period, and had higher Clinical Pulmonary Infection Score values and lower Pao2/Fio2 ratios. By day 3, patients defined as clinical failures remained more severely ill and continued to have worse oxygenation. In multivariate analysis, 4 factors were independently associated with clinical failure: older age, duration of ventilation before enrollment, presence of neurologic disease at admission, and failure of the Pao2/Fio2 ratio to improve by day 3. Repeating this multivariable model in only surviving patients suggested that persistence of fever was the only variable associated with clinical failure. CONCLUSIONS: Clinical characteristics correlate with eventual outcomes in VAP. Failure of the Pao2/Fio2 ratio and fever to improve are independently associated with clinical failure. We suggest that clinicians follow these measures and consider integrating them in their decisions as to when to reevaluate persons with VAP who are not improving.     

Sensitive enzyme-linked immunosorbent assay with urine samples: a tool for surveillance of schistosomiasis japonica

An enzyme-linked immunosorbent assay (ELISA) to detect antibodies to Schistosoma japonicum soluble egg antigens (SEA) in un-concentrated urine was developed. The urine ELISA was applied to samples collected in a schistosomiasis-endemic village in China. The levels of anti-SEA antibodies detected in urine correlated well with those obtained with paired serum samples (r = 0.694, p<0.0001). Among 129 serum ELISA positives, 112 (86.8%) were positive by urine ELISA, while all 40 serum ELISA negatives from a non-endemic area were negative. The levels of anti-SEA in urine samples were stable up to 8 weeks of storage at 37 degrees C, with sodium azide as a preservative. Therefore, ELISA with urine samples can be used for the surveillance of schistosomiasis.     

DNA methylation in inflammatory bowel disease and beyond

Inflammatory bowel disease(IBD)is a consequence of the complex,dysregulated interplay between genetic predisposition,environmental factors,and microbial composition in the intestine.Despite a great advancement in identifying host-susceptibility genes using genome-wide association studies(GWAS),the majority of IBD cases are still underrepresented.The immediate challenge in post-GWAS era is to identify other causative genetic factors of IBD.DNA methylation has received increasing attention for its mechanistical role in IBD pathogenesis.This stable,yet dynamic DNA modification,can directly affect gene expression that have important implications in IBD development.The alterations in DNA methylation associated with IBD are likely to outset as early as embryogenesis all the way until old-age.In this review,we will discuss the recent advancement in understanding how DNA methylation alterations can contribute to the development of IBD.     

Real-time three-dimensional fetal echocardiography--optimal imaging windows

A total of 15 fetuses were scanned using 2-D array volumetric ultrasound (US). Acquired cardiac data were converted for rendering dynamic 3-D surface views and reformatting cross-sectional views. The image usefulness was compared between the data obtained from subcostal/subxiphoid and other imaging windows; the former are usually free of acoustic shadowing. Of 60 data sets recorded, 12 (20%) were acquired through subcostal windows in 6 (40%) patients. Subcostal windows were unavailable from the remaining patients due to unfavourable fetal positions. Of the 12 sets, 6 (50%) provided the dynamic 3-D and/or cross-sectional views of either the entire fetal heart or a great portion of it for sufficient assessments of its major structures and their spatial relationships. Of 48 data sets from other windows, only 9 (19%) provided such 3-D and/or cross-sectional views; the lower rate being due to acoustic shadowing. Real-time 3-D US is a convenient method for volumetric data acquisition. Through subcostal windows, useful information about the spatial relationships between major cardiac structures can be acquired. However, to offer detailed information, considerable improvement in imaging quality is needed.     

眼动追踪技术在抑郁症中的诊断应用

抑郁症是以持久显著的心境低落为主要临床特征的精神障碍。特异性评估抑郁症的指标和技术仍然是一个难题，寻找高效、准确的抑郁症诊断方法一直是研究的热点。已有大量的研究证明抑郁症患者存在眼动数据的异常。文章概述了眼动技术在抑郁症诊断中的应用情况，主要在基本指标、实验范式和对注意力偏向的识别方面进行阐述，并对将来的研究方向进行探讨。