What action can prolong the usage time of oxygen cylinders when a switch to backup cylinders is made?

Switching to manual ventilation is a strategic action that can significantly prolong the usage time of oxygen cylinders when transitioning to backup cylinders. Manual ventilation allows for greater control over the amount of oxygen being administered to the patient. By adjusting the ventilation rate, the clinician can optimize oxygen delivery based on the patient's current needs, thus conserving oxygen in the backup cylinders.

In contrast, increasing the flow rate would deplete the oxygen supplies more quickly, as more gas is being used per minute. Total intravenous anesthesia, while beneficial in some contexts, does not assist in prolonging the time for the oxygen cylinders since it involves alternative means of anesthesia rather than conserving oxygen. Replacing carbon dioxide absorbers also does not directly correlate with extending oxygen usage; it pertains more to the management of carbon dioxide levels in breathing circuits rather than the preservation of the oxygen supply.