Aestiva ventilation mode selector switch failures.

We describe three cases of previously unreported failures of the Bag-Ventilator Switch in Aestiva/5 anesthesia machines (GE Healthcare/Datex-Ohmeda, Madison, WI). Each failure mode produced a large breathing-circuit leak. Examination of the switches revealed a cracked toggle actuator, residue build-up, and a cracked selector switch housing as causes for the failures. When a leak with no visible cause develops, consider advancing the mode selector switch fully to its mechanical limit or consider that the toggle actuator or its anchoring mechanism may have failed. These cases demonstrate that it is imperative to always be prepared to immediately use an alternate method for ventilation. Cases describing failure to ventilate due to sudden equipment malfunction underscore the need to always have functioning backup ventilation equipment available.