Clinical outcomes of severe COVID-19 patients receiving early VV-ECMO and the impact of pre-ECMO ventilator use.

Acute respiratory distress syndrome (ARDS) in COVID-19 patients is associated with poor clinical outcomes and high mortality rates, despite the use of mechanical ventilation. Veno-Venous Extracorporeal membrane Oxygenation (VV-ECMO) in these patients is a viable salvage therapy. We describe clinical outcomes and survival rates in 52 COVID-19 patients with ARDS treated with early VV-ECMO at a large, high-volume center ECMO program. Outcomes included arterial blood gases, respiratory parameters, inflammatory markers, adverse events, and survival rates. Patients' mean age was 47.8 ± 12.1 years, 33% were female, and 75% were Hispanic. At the end of study period, 56% (n = 29) of the patients survived and were discharged and 44% (n = 23) of the patients expired. Survival rate was 75.0% (9 out of 12) in patients placed on ECMO prior to mechanical ventilation. Longer duration on mechanical ventilation prior to ECMO intervention was associated with a 31% (aOR = 1.31, 95% CI, 1.00-1.70) increased odds of mortality after adjusting for age, gender, BMI, number of comorbid conditions, and post-ECMO ventilator days. Early and effective ECMO intervention in critical ill COVID-19 patients might be a valuable strategy in critical care settings to increase their odds of survival.

The pro-angiogenic properties of multi-functional bioactive glass composite scaffolds.

The angiogenic properties of micron-sized (m-BG) and nano-sized (n-BG) bioactive glass (BG) filled poly(D,L lactide) (PDLLA) composites were investigated. On the basis of cell culture work investigating the secretion of vascular endothelial growth factor (VEGF) by human fibroblasts in contact with composite films (0, 5, 10, 20 wt %), porous 3D composite scaffolds, optimised with respect to the BG filler content capable of inducing angiogenic response, were produced. The in vivo vascularisation of the scaffolds was studied in a rat animal model and quantified using stereological analyses. The prepared scaffolds had high porosities (81-93%), permeability (k = 5.4-8.6 x 10⁻9 m²) and compressive strength values (0.4-1.6 MPa) all in the range of trabecular bone. On composite films containing 20 wt % m-BG or n-BG, human fibroblasts produced 5 times higher VEGF than on pure PDLLA films. After 8 weeks of implantation, m-BG and n-BG containing scaffolds were well-infiltrated with newly formed tissue and demonstrated higher vascularisation and percentage blood vessel to tissue (11.6-15.1%) than PDLLA scaffolds (8.5%). This work thus shows potential for the regeneration of hard-soft tissue defects and increased bone formation arising from enhanced vascularisation of the construct.