Table 5:

Issues encountered with the use of anesthesia machines in COVID-19 critically patients and relative proposed solutions.

Problem	Proposed solution
Audibility and correct perception of alarms potentially associated with life-threatening AM failures	· Constant presence of anesthesia providers in the clinical team; · Maximize staff proximity to the workstation.
Condensed water accumulation in the circuit causing obstruction of HMEF or filters Reduced reliability of flow sensors	· Use of high fresh gas flow (dryer gas mixture); · HME perpendicularly positioned above the endotracheal tube to reduce the backflow of excess moisture into the circuit; · Use of heated breathing circuits, condensers and water traps to limit water accumulation.
Endotracheal tube obstruction	· Dedicated endotracheal tube cleaning devices.
Frequent disconnection due to filter change and machine self-tests	· Temporary use of a portable ventilator during disconnection to maintain protective ventilation and PEEP settings.
Limited functionality for the assessment of respiratory mechanics	· Prioritize the use of newer AMs in more complicated patients considering the possibility to perform measurements of respiratory mechanics (e.g. end-inspiratory and end-expiratory pauses).

HMEF: Heat and Moisture Exchanger with Filter; PEEP: Positive End-Expiratory Pressure; AM: Anesthesia Machine