Aerodynamic analysis of hospital ventilation according to seasonal variations. A simulation approach to prevent airborne viral transmission pathway during Covid-19 pandemic.

During the Covid-19 pandemic, location of the SARS-CoV-2 infected patients inside the hospital is a major issue to prevent viral cross-transmission. The objective of this study was to evaluate the risk of contamination through aerosol by using a global approach of the multiple environmental parameters to simulate, including seasonal context. A computational fluid dynamic (CFD) simulation based on the Lattice Boltzmann Method approach was used to predict airflow on the entire floor of a private hospital in Paris. The risk of contamination outside the rooms was evaluated by using a water vapor mass fraction tracker. Finally, the air contamination was estimated by a "cough model" producing several punctual emissions of contaminated air from potentially infected patients. In a winter configuration, the simulation showed a well-balanced ventilation on the floor and especially inside the rooms. After cough emissions from COVID-positive rooms, no significant contamination was observed in the circulation area, public waiting space and nurse office. On the contrary, in a summer configuration, the temperature difference due to the impact of the sun radiation between both sides of the building created additional air transport increasing the contamination risk in neighboring rooms and public spaces. Airborne spread was limited to rooms during winter conditions. On the contrary, during summer conditions, market airflow with potentially contaminated air coming from rooms located on the side of the building exposed to solar radiation was evidenced. These observations have implications to locate infected patients inside the building and for the conception of future health care structures.

Surgical Revascularization With Cardiopulmonary Bypass on a Patient With Severe COVID-19.

The coronavirus disease 2019 (COVID-19) may lead to an acute respiratory distress syndrome by an inappropriate cytokine response and may predispose to a prothrombotic state through multiple pathways. Both can complicate the management of cardiac surgery with cardiopulmonary bypass, which is known to activate the hemostatic system and to exacerbate systemic inflammatory response. Little is known about the impact of cardiac surgery with cardiopulmonary bypass on viral pneumonia, particularly with the new coronavirus. In this article, we describe the case of a diabetic patient with COVID-19 and a concomitant 3-vessel disease with a formal indication for surgical revascularization, who unexpectedly presented with a high heparin resistance during cardiopulmonary bypass. Emphasis is placed on the importance of multidisciplinary team discussions before surgery, on the thorough preoperative assessment, and on the perioperative management, particularly regarding mechanical ventilation and anticoagulation.

Guidelines: Anaesthesia in the context of COVID-19 pandemic.

OBJECTIVES: The world is currently facing an unprecedented healthcare crisis caused by the COVID-19 pandemic. The objective of these guidelines is to produce a framework to facilitate the partial and gradual resumption of intervention activity in the context of the COVID-19 pandemic. METHODS: The group has endeavoured to produce a minimum number of recommendations to highlight the strengths to be retained in the 7 predefined areas: (1) protection of staff and patients; (2) benefit/risk and patient information; (3) preoperative assessment and decision on intervention; (4) modalities of the preanaesthesia consultation; (5) specificity of anaesthesia and analgesia; (6) dedicated circuits and (7) containment exit type of interventions. RESULTS: The SFAR Guideline panel provides 51 statements on anaesthesia management in the context of COVID-19 pandemic. After one round of discussion and various amendments, a strong agreement was reached for 100% of the recommendations and algorithms. CONCLUSION: We present suggestions for how the risk of transmission by and to anaesthetists can be minimised and how personal protective equipment policies relate to COVID-19 pandemic context.