Power loss with the Aestiva/5 anaesthetic machine

Abstract

We wish to highlight a potential flaw in the design of some versions of the Datex-Ohmeda Aestiva/5 anaesthetic machine (GE Healthcare, Madison, WI, USA). On a routine anaesthetic machine check one morning, we found that we were unable to switch on the integrated monitoring. On further investigation, we discovered that there was no power being delivered to either the monitor or the ventilator (which was running on its backup battery). The Aestiva/5 machines may be configured in various different ways. Our machines have two drawers and a shelf underneath the work surface. This leaves a gap between the lowest drawer and the footrest, which in our institution is often used for further storage. Behind this space is an electrical transformer. This is optional and not present on all versions of the Aestiva/5. The machine in question had a jet ventilator stored in that gap. On closer inspection, it appeared that the box containing the jet ventilator had dislodged a removable panel at the back of this space (Fig. 1) pushing it back onto a switch on the transformer and cutting off the power supply to the monitor and the ventilator. The design of the panel is such that it will dislodge easily at its right-hand edge, which is the side of the power switch on the transformer (Fig. 2). The switch has no guard around it (as there is on the main power switch on the back of the machine) to prevent it from being accidentally switched off. Panel dislodged at right-hand edge. The transformer behind the panel. We have informed GE Healthcare of this and whilst waiting for them to arrange a more permanent solution, we have temporarily covered the switch to ensure that it cannot be pressed accidentally, yet remains visible and easily accessible. We would like to highlight this potential problem to all users of these machines as intra-operative power loss could have serious consequences.