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Background:We created a high dimensionality healthy human Immunome atlas by interrogating the peripheral blood mononuclear cells (PBMC) of >200 healthy subjects (cord blood to adult) with 63 unique mechanistic and phenotypic markers per cell by mass cytometry (CyTOF). This database is built with an open source, web-based bioinformatics toolkit, enabling its mining and uploading of datasets for comparison with the EPIC healthy database.Objectives:Here, we demonstrate the platform’s ability to identify the immunological differences of mechanistically important cell subsets in the uploaded data in comparison with EPIC.Methods:CyTOF data from 37 healthy elderly (>60 years old) was uploaded onto the EPIC Discovery tool where down-sampling, normalising and FlowSOM (Flow analysis with Self-Organising Maps) clustering were done with the EPIC database for comparison. Online visualisation outputs include cluster frequency boxplots, correspondence analysis (CA) plot and markers expression heat-map. The CA 2-dimensional plot depicts the global differences in immune cells composition between subjects with proximity between points (subjects) denoting similarity. Kruskal-Wallis test was done to identify age groups differences.Results:Increasing distances on the CA plot with age were observed with the elderly being farthest from the new-borns. Notably, we observed significant changes in naive CD4+IL8+T cells (p<1×10-20), memory CD4+IL17A+T cells (p<1×10-20) and type 2 innate lymphoid cells (ILC2) (Lin-CD7+CD25+CD127+CD161+, p<1×10-17) with increasing age. The naive CD4+IL8+T cells (median: 0.68%, interquartile range: 0.415 to 1.055% of CD45+ PBMC) and ILC2 (0.09%, 0.065 to 0.12%) were lowest and memory IL17A+T cells (0.58%, 0.41 to 0.905%) highest in the elderly. Significantly, the memory IL17A+T cells and ILC2 have been implicated in the pathogenesis of auto-immune conditions1,2.Conclusion:With EPIC, we have created an online tool enabling data uploading for comparison to a healthy database, allowing the holistic characterisation of immunological changes in different clinical scenarios. Using it, we were able to identify mechanistically important differences in immune cells composition in a distinct clinical cohort (elderly) compared to the younger ages. Translationally, the EPIC platform can be utilised similarly to catalyse the discovery process in auto-immune diseases interrogated with the EPIC antibody panels.References:[1]Fasching P, Stradner M, Graninger W, Dejaco C, Fessler J. Therapeutic Potential of Targeting the Th17/Treg Axis in Autoimmune Disorders. Molecules. 2017 Jan 14;22(1). pii: E134.[2]Klose CS, Artis D. Innate lymphoid cells as regulators of immunity, inflammation and tissue homeostasis. Nat Immunol. 2016 Jun 21; 17(7): 765-74.Disclosure of Interests:None declared

Background: Self-made Y-connector jet-oxygenation devices with wide-bore expiratory port have been described but not evaluated in infant models. Little is known about the effect of oxygen flow rates on jet oxygenation via transtracheal cannula. Aims:The aim of this study was to compare two self-made Y-connector jet-oxygenation devices against the ENK oxygen flow modulator™, and the effects of three different oxygen flow rates based on body weight, in both unobstructed and obstructed airways, on the time to re-oxygenate in a rabbit infant model. The aim was also to assess the effectiveness of an oxygen flow rate of 1 L/min, for re-oxygenation using ENK oxygen flow modulator™.Methods: Nine rabbits were grouped in threes: Group 1 had a Y-connector attached to an intravenous infusion tubing, Group 2 the same Y-connector attached to a perfusion oxygenator tubing and Group 3, ENK oxygen flow modulator™. From oxygen saturations of 75%, the rabbits were jet oxygenated using their assigned device for 10 minutes at each flow rate of 1 L/kg/min, 1.5 L/kg/min and 2 L/kg/min with their airways unobstructed and later, obstructed. Group 3 had additional experiments involving an absolute oxygen flow rate of 1 L/min. Results:All devices resulted in rapid re-oxygenation within 40 seconds at flow rates of 1 L/kg/min. Oxygen flow rates beyond 1 L/kg/min in obstructed airways resulted in high airway pressures. All rabbits in Group 3 with obstructed airways died from barotrauma when jet oxygenated at a flow rate of 1.5 L/kg/min. When an oxygen flow rate of 1 L/min was used in Group 3, there was a failure to re-oxygenate to SpO 2 90% within 120 seconds in some rabbits.Conclusion: Our animal model results suggest that self-made Y-connector jet-oxygenation devices with wide-bore expiratory port are efficacious and perhaps safer than ENK oxygen flow modulator™ in obstructed airways, and jet oxygenation with minimal oxygen flow rates starting at 1 L/kg/min or (age [years] + 4) L/min, whichever lower, should be considered.

Ultrasound-guided cannulation of a central venous catheter into the internal jugular vein (IJV) was performed in the intensive care unit for a critically ill patient. The catheter was inserted into the subclavian artery distally, despite prior ultrasound confirmation of the guidewire position using both the in-plane and out-of-plane views. The catheter was removed successfully by the interventional radiologist with a closure device. To our knowledge, there have been previous case reports of subclavian artery injury during IJV cannulation with ultrasound guidance, but rarely in the setting whereby the guidewire was visualized before dilatation and railroading of the catheter. This case demonstrates that the confirmation of the guidewire in the proximal segment of the vein is insufficient to exclude arterial cannulation.

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