Table 5 Issues encountered with the use of anesthesia machines in COVID-19 critically patients and relative proposed solutions

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).