Daily Ards Research Analysis

BACKGROUND: Non-invasive assessment of respiratory drive and effort in spontaneously breathing ARDS patients is challenging, yet clinically relevant. We explored whether hierarchical clustering applied to electrical impedance tomography (EIT- a radiation-free non-invasive lung imaging technique) identifies ARDS sub-phenotypes with increased drive and effort. RESULTS: Thirty intubated patients with ARDS on assisted mechanical ventilation were monitored by EIT and esophageal pressure during a decremental positive end-expiratory pressure (PEEP) trial. A comprehensive EIT assessment was made (computed variables n = 180) during tidal breathing at different PEEP levels. Agglomerative nesting was applied to scaled data distances. Three clusters of ARDS were identified: inhomogeneous ventilation, unmatched V'/Q, and mismatched V'/Q. The unmatched V'/Q cluster had the highest respiratory drive (p = 0.045) and effort (p = 0.021) at lower PEEP, and experienced longer length of ICU stay (p = 0.019). CONCLUSIONS: Higher PEEP levels reduced drive of the unmatched V'/Q cluster, mitigating the physiological differences. Clustering approaches to EIT data identify physiologically and clinically relevant sub-phenotypes of ARDS.

Acute lung injury (ALI) is a serious lung disease that tends to progress to acute respiratory distress syndrome (ARDS). This study was aimed to seek new biomarkers of ALI to provide a basis for monitoring the progress of ALI in time. A human bronchial epithelial cell line (HBEC3-KT) was treated with 1 μg/ml lipopolysaccharide (LPS) to induce the ALI response. The expression of LINC00487 and hsa-miR-663b in LPS-treated HBEC3-KT cells was detected by RT-qPCR. The regulation of hsa-miR-663b by LINC00487 was investigated using a dual luciferase assay and an over-expression experiment. Cell proliferation and apoptosis were detected by the CCK-8 assay and annexin V-FITC kit. Serum levels of LINC00487 and hsa-miR-663b were detected by collecting blood samples from ALI patients (with or without ARDS), and the ROC curve was constructed to assess their clinical value in ALI. LPS inhibited proliferation of HBEC3-KT cells and promoted their apoptosis and inflammatory response, which were further enhanced by LINC00487 over-expression and reversed by an hsa-miR-663b mimic. The hsa-miR-663b mimic weakened the luciferase activity of HBEC3-KT cells transfected with the luciferase vector of wild-type LINC00487. The cellular level of hsa-miR-663b was down-regulated by LINC00487 over-expression and increased by LINC00487 knockdown. The ROC curve showed that LINC00487 combined with hsa-miR-663b effectively diagnosed ALI (AUC = 0.840) and was a classifier for ALI patients with or without ARDS (AUC = 0.822). Serum LINC00487 and hsa-miR-663b levels are valuable biomarkers of ALI and can monitor the ALI progress. LINC00487 may promote ALI progression by negatively regulating hsa-miR-663b.

Patients with severe burn injuries are at risk of developing acute respiratory distress syndrome (ARDS). Modern ARDS management does not typically factor in how burn injury influences lung dynamics during ventilator management. Obtaining indirect intrapleural pressures via esophageal pressure monitoring (Pes) may provide unique guidance on optimal positive end expiratory pressure (PEEP) titration to prevent alveolar collapse while ensuring safe plateau pressures but is not well described in burn injured patients. This work examined the use of Pes in burn injured patients with ARDS to determine its effect on ventilator changes. Burn injured patients admitted to an ABA verified burn center that developed ARDS by the Berlin definition and received Pes were retrospectively reviewed to determine ventilator settings and oxygenation trends. Severity of ARDS and oxygenation were determined by PaO2 to FiO2 (P/F) ratios and oxygenation indices (OI) prior to Pes use, and at 1-, 3- and 5-day intervals following initiation. Of the 23 patients included, the median revised Baux score was 91.6 (73.9-114.6), and the mortality rate was 82.6%. Increases in PEEP were required [12 (4) vs 17 (4); P < .0001] following Pes initiation. P/F ratios increased by day 5 post-Pes monitoring [300 (35.1)] compared to pre- [141 (26.5); P = .0020], 1 day post- [169 (26.5); P = .0134] and 3 days post- [179 (29.4); P = .0325] monitoring. OI between pre-Pes monitoring and day 5 post Pes monitoring, were not significant [17.3 (1.92) vs 13.4 (2.57)]. A strategy incorporating Pes to guide ventilator management in burn injured patients with ARDS may be used.