Thank you for the opportunity to respond to the letter from Gunter et al. , in which they correctly describe both the function of the bag-to-ventilator switch and the results produced by the broken rocker-holding mechanism. The entire control panel assembly from the Aestiva used during this case was returned to Datex-Ohmeda, where the cause of the failure was determined. Further investigation into the root cause of the breakage determined no design, manufacturing, assembly, or service issues that may have resulted in this break. Although every attempt is made to design and manufacture robust and reliable products, occasionally a part may fail for reasons that remain indeterminable.

The authors continue by describing sporadic episodes during which the bag-to-ventilator switch seems to incompletely exclude the ventilator when switched into the bag mode. Unfortunately, these additional events have not been reported to Datex-Ohmeda. In the absence of such reports, no investigations have been implemented. We will, however, begin an internal review of the bag-to-ventilator switch.

Datex-Ohmeda agrees with the authors regarding the need for an auxiliary method to provide ventilation during administration of each anesthetic, as required by the U.S. Food and Drug Administration, and wishes to thank the authors for their report. In addition, Datex-Ohmeda encourages all anesthesia providers and anesthesia technicians to report possible problems with any piece of equipment to the respective manufacturer so that proper investigations may be conducted.