Cell-Free DNA as Biomarker for Sepsis by Integration of Microbial and Host Information.

BACKGROUND: Cell-free DNA (cfDNA) is emerging as a biomarker for sepsis. Previous studies have been focused mainly on identifying blood infections or simply quantifying cfDNA. We propose that by characterizing multifaceted unexplored components, cfDNA could be more informative for assessing this complex syndrome. METHODS: We explored multiple aspects of cfDNA in septic and nonseptic intensive care unit (ICU) patients by metagenomic sequencing, with longitudinal measurement and integrative assessment of plasma cfDNA quantity, human cfDNA fragmentation patterns, infecting pathogens, and overall microbial composition. RESULTS: Septic patients had significantly increased cfDNA quantity and altered human cfDNA fragmentation pattern. Moreover, human cfDNA fragments appeared to comprise information about cellular oxidative stress and could indicate disease severity. Metagenomic sequencing was more sensitive than blood culture in detecting bacterial infections and allowed for simultaneous detection of viral pathogens. We found differences in microbial composition between septic and nonseptic patients and between survivors and nonsurvivors by 28-day mortality, both on the first day of ICU admission and across the study period. By integrating all the information into a machine learning model, we achieved improved performance in identifying sepsis and prediction of clinical outcome for ICU patients with areas under the curve of 0.992 (95% CI 0.969-1.000) and 0.802 (95% CI 0.605-0.999), respectively. CONCLUSIONS: We were able to diagnose sepsis and predict mortality as soon as the first day of ICU admission by integrating multifaceted cfDNA information obtained in a single metagenomic assay; this approach could provide important advantages for clinical management and for improving outcomes in ICU patients.

Mechanical Ventilation Discontinuation Practices in Asia: A Multinational Survey.

Rationale: There are limited data on mechanical discontinuation practices in Asia. Objectives: To document self-reported mechanical discontinuation practices and determine whether there is clinical equipoise regarding protocolized weaning among Asian Intensive Care specialists. Methods: A survey using a validated questionnaire, distributed using a snowball method to Asian Intensive Care specialists. Results: Of the 2,967 invited specialists from 20 territories, 2,074 (69.9%) took part. The majority of respondents (60.5%) were from China. Of the respondents, 42% worked in intensive care units (ICUs) where respiratory therapists were present; 78.9% used a spontaneous breathing trial as the initial weaning step; 44.3% frequently/always used pressure support (PS) alone, 53.4% intermittent spontaneous breathing trials with PS in between, and 19.8% synchronized intermittent mandatory ventilation with PS as a weaning mode. Of the respondents, 56.3% routinely stopped feeds before extubation, 71.5% generally followed a sedation protocol or guideline, and 61.8% worked in an ICU with a weaning protocol. Of these, 78.2% frequently always followed the protocol. A multivariate analysis involving a modified Poisson regression analysis showed that working in an ICU with a weaning protocol and frequently/always following it was positively associated with an upper-middle-income territory, a university-affiliated hospital, or in an ICU that employed respiratory therapists; and negatively with a low-income or lower-middle-income territory or a public hospital. There was no significant association with "in-house" intensivist at night, multidisciplinary ICU, closed ICU, or nurse-patient ratio. There was heterogeneity in agreement/disagreement with the statement, "evidence clearly supports protocolized weaning over nonprotocolized weaning." Conclusions: A substantial minority of Asian Intensive Care specialists do not wean patients in accordance with the best available evidence or current guidelines. There is clinical equipoise regarding the benefit of protocolized weaning.