Background: Previous studies suggest that prone positioning (PP) can increase PaO 2 /FiO 2 and reduce mortality in moderate to severe acute respiratory distress syndrome (ARDS). The aim of our study was to determine whether the early use of PP combined with non-invasive ventilation (NIV) or high-flow nasal cannula (HFNC) can avoid the need for intubation in moderate to severe ARDS patients. Methods: This prospective observational cohort study was performed in two teaching hospitals. Non-intubated moderate to severe ARDS patients were included and were placed in PP with NIV or with HFNC. The efficacy in improving oxygenation with four support methods-HFNC, HFNC+PP, NIV, NIV+PP-were evaluated by blood gas analysis. The primary outcome was the rate of intubation.

The purpose of this study was to assess the value of metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) for the diagnosis of severe respiratory diseases based on interpretation of sequencing results. BALF samples were harvested and used for mNGS as well as microbiological detection. Infectious bacteria or fungi were defined according to relative abundance and number of unique reads. We performed mNGS on 35 BALF samples from 32 patients. The positive rate reached 100% in the mNGS analysis of nine immunocompromised patients. Compared with the culture method, mNGS had a diagnostic sensitivity of 88.89% and a specificity of 74.07% with an agreement rate of 77.78% between these two methods. Compared with the smear method and PCR, mNGS had a diagnostic sensitivity of 77.78% and a specificity of 70.00%. In 13 cases, detection results were positive by mNGS but negative by culture/smear and PCR. The mNGS findings in 11/32 (34.4%) cases led to changes in treatment strategies. Linear regression analysis showed that diversity was significantly correlated with interval between disease onset and sampling. Dynamic changes in reads could indirectly reflect therapeutic effectiveness. BALF mNGS improves sensitivity of pathogen detection and provides guidance in clinical practice. Potential pathogens can be identified based on relative abundance and number of unique reads.

IntroductionSince 2008, severe cases of emerging human adenovirus type 55 (HAdV-55) in immunocompetent adults have been reported sporadically in China. The clinical features and outcomes of the most critically ill patients with severe acute respiratory distress syndrome (ARDS) caused by HAdV-55 requiring invasive mechanical ventilation (IMV) and/or extracorporeal membrane oxygenation (ECMO) are lacking.MethodsWe conducted a prospective, single-center observational study of pneumonia with ARDS in immunocompetent adults admitted to our respiratory ICU. We prospectively collected and analyzed clinical, laboratory, radiological characteristics, sequential tests of viral load in respiratory tract and blood, treatments and outcomes.ResultsThe results for a total of five consecutive patients with severe ARDS with confirmed HAdV-55 infection were included. All five patients were immunocompetent young men with a median age of 32 years. The mean time from onset to dyspnea was 5 days. Arterial blood gas analysis at ICU admission revealed profound hypoxia. Mean partial oxygen pressure/fraction of inspired oxygen was 58.1. Mean durations from onset to a single-lobe consolidation shown on chest X-rays (CXRs) and, from the first positive CXR to bilateral multilobar lung infiltrates, were 2 days and 4.8 days, respectively. The viral load was higher than 1 × 108 copies in three patients and was 1 × 104 in one patient. It was negative in the only patient who survived. The mean duration for noninvasive positive pressure ventilation (NPPV) failure and IMV failure were 30.8 hours and 6.2 days, respectively. Four patients received venovenous ECMO. Four (80%) of the five patients died despite receiving appropriate respiratory support.ConclusionsHAdV-55 may cause severe ARDS in immunocompetent young men. Persistent high fever, dyspnea and rapid progression to respiratory failure within 2 weeks, together with bilateral consolidations and infiltrates, are the most frequent clinical manifestations of HAdV-55-induced severe ARDS. Viral load monitoring may help predict disease severity and outcome. The NPPV and IMV failure rates were very high, but ECMO may still be the respiratory support therapy of choice.Trial registrationClinicaltrials.gov NCT01585922. Registered 20 April 2012

BackgroundThere has not been sufficient evidence to support the Asians being less susceptible to pulmonary embolism (PE) than other ethnicities, because the prevalence of PE/deep venous thrombosis (DVT) in different racial and ethnic groups has not been carefully studied until recently except in Caucasians. To test the hypothesis that the Chinese population has a lower risk for PE, this study comprehensively assessed the hospital-based incidence and case fatality rates for PE during the 1997–2008 in China.MethodsA registration study of patients with suspected PE syndromes admitted to 60 level-3 hospitals involved in the National Cooperative Project for the Prevention and Treatment of Venous Thromboembolism (NCPPT) was conducted from January 1997 to December 2008. The only exclusion criterion was an age of less than 18 years. Helical computed tomography scan, ventilation-perfusion lung scintigraphy or pulmonary angiography was carried out before or after hospitalization. All images were reviewed and evaluated independently by two specialists.ResultsA total of 18,206 patients were confirmed with PE from 16,972,182 hospital admissions. The annual incidence was 0.1% (95% CI: 0.1% to 0.2%). The overall incidence of PE in male patients (0.2%, 95% CI: 0.1% to 0.3%) was higher than that in female patients (0.1% and 95% CI: 0.0% to 0.1%). An increasing incidence gradient for PE was noticed from Southern to Northern China. In addition, the case fatality rate was apparently decreasing: 25.1% (95% CI: 16.2% to 36.9%) in 1997 to 8.7% (95% CI: 3.5% to 15.8%) in 2008.ConclusionsOur findings suggest the relatively stable PE incidence and decreasing fatality trends in Chinese hospitals may be partially attributable to the implementation of the NCCPT and suggest the government should reevaluate the severity of PE so that health resources for the prevention, diagnosis and treatment of PE could be used to their fullest.

IntroductionCritically ill patients with chronic obstructive respiratory diseases (CORD) who require intensive care unit (ICU) admission are at particular risk for invasive bronchial-pulmonary aspergillosis (IBPA). The purpose of this study is to investigate clinical features for rapid recognition of IBPA in critically ill patients with CORD.MethodsWe included 55 consecutive CORD patients in a respiratory ICU in a prospective, single-center, cohort study. In this study, IBPA combined two entities: ATB and IPA.ResultsThirteen of 55 patients were diagnosed with IBPA. Before ICU admission, three variables were independent predictors of IBPA with statistical significance: more than three kinds of antibiotics used before the ICU admission, accumulated doses of corticosteroids (>350 mg) received before the ICU admission, and APACHE II scores >18 (OR, 1.208; P = 0.022; OR, 8.661; P = 0.038; and OR, 19.488; P = 0.008, respectively). After ICU admission, more IBPA patients had a high fever (>38.5°C) (46.2% versus 11.9%; P = 0.021), wheeze without exertion (84.6% versus 50.0%; P = 0.027), dry rales (84.6% versus 40.4%; P = 0.005), higher white blood cell counts (21 × 109/L versus 9.4 × 109/L; P = 0.012), lower mean arterial pressures (77.9 mm Hg versus 90.5 mm Hg; P = 0.019), and serum creatinine clearances (36.2 ml/min versus 68.8 ml/min; P < 0.001), and liver-function and coagulation abnormalities. Bronchospasm, sputum ropiness, and plaque formation were more common for IBPA patients during bronchoscopy (66.7% versus 14.3%; P = 0.082; 18% versus 0; P = 0.169; and 73% versus 13%; P = 0.003, respectively). More IBPA patients had nodules and patchiness on chest radiograph on day 1 of admission, which rapidly progressed to consolidation on day 7. IBPA mortality was higher than that of non-IBPA patients (69.2% versus 16.7%; P = 0.001).ConclusionsIBPA may be suspected in critically ill CORD patients with respiratory failure and clinical and bronchoscopic manifestations of severe infection, bronchospasm, and rapid progression of radiologic lesions that are irresponsive to steroids and antibiotics. To avoid misdiagnosis and establish the microbiologic etiology, early bronchoscopy and tight radiologic follow-up should be performed.

IntroductionCritically ill chronic obstructive pulmonary disease (COPD) patients are at particular risk of invasive pulmonary aspergillosis (IPA). Our aims were to determine whether bronchoalveolar lavage fluid (BALF) galactomannan (GM) has a higher sensitivity and specificity than serum GM or lower respiratory tract (LRT) sample culture. Furthermore, we aimed to investigate what the optimal cut-off value would be for BALF GM.MethodsIn this prospective single-center study, BALF and serum samples were collected from critically ill COPD patients on the first day of their intensive care unit admission.ResultsOf 50 critically ill COPD patients admitted, BALF and serum samples were collected in 34 patients. According to the receiver operating characteristics (ROC) curve, an optical density (OD) ratio of 0.8 was chosen as the cut-off value for GM in BALF. Compared to serum GM and LRT Aspergillus isolation, BALF GM yield a better sensitivity, specificity, positive and negative predictive values of 88.9%, 100%, 100% and 94.4%, respectively. Areas under the ROC curve were 0.912 (95%CI, 0.733 to 0.985) for BALF GM, and 0.879 (95%CI, 0.691 to 0.972) for serum GM results from the first day of ICU admission. Pairwise comparison of ROC curves showed P = 0.738. The OD ratio of BALF GM in IPA patients were significantly higher than those of non-IPA patients (2.88 ± 2.09 versus 0.49 ± 0.19, P = 0.009), and the OD ratio of BALF GM was significantly higher than serum GM in IPA patients (2.88 ± 2.09 versus 0.87 ± 0.47, P = 0.023). Positive BALF GM was seen earlier than LRT secretion culture (1 day versus 3.8 days).ConclusionsCompared to serum GM and LRT Aspergillus isolation, BALF GM seems to have a better sensitivity in the diagnosis of IPA in critically ill COPD patients. The ROC curve suggests a possible cut-off value of 0.8 for GM from BALF specimens in critically ill COPD patients.

Rationale Our pilot study suggested that noninvasive ventilation (NIV) reduced the need for intubation compared with conventional administration of oxygen on patients with “early” stage of mild acute respiratory distress syndrome (ARDS, PaO 2 /FIO 2 between 200 and 300). Objectives To evaluate whether early NIV can reduce the need for invasive ventilation in patients with pneumonia-induced early mild ARDS. Methods Prospective, multicenter, randomized controlled trial (RCT) of NIV compared with conventional administration of oxygen through a Venturi mask. Primary outcome included the numbers of patients who met the intubation criteria. Results Two hundred subjects were randomized to NIV ( n = 102) or control ( n = 98) groups from 21 centers. Baseline characteristics were similar in the two groups. In the NIV group, PaO 2 /FIO 2 became significantly higher than in the control group at 2 h after randomization and remained stable for the first 72 h. NIV did not decrease the proportion of patients requiring intubation than in the control group (11/102 vs. 9/98, 10.8% vs. 9.2%, p = 0.706). The ICU mortality was similar in the two groups (7/102 vs. 7/98, 4.9% vs. 3.1%, p = 0.721). Multivariate analysis showed minute ventilation greater than 11 L/min at 48 h was the independent risk factor for NIV failure (OR, 1.176 [95% CI, 1.005–1.379], p = 0.043). Conclusions Treatment with NIV did not reduce the need for intubation among patients with pneumonia-induced early mild ARDS, despite the improved PaO 2 /FIO 2 observed with NIV compared with standard oxygen therapy. High minute ventilation may predict NIV failure. Trial registration NCT01581229 . Registered 19 April 2012 Electronic supplementary material The online version of this article (10.1186/s13054-019-2575-6) contains supplementary material, which is available to authorized users.

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