To the Editor

Over a period of 2 weeks, in 4 different operating rooms, 4 monitors attached to 4 different Aisys Datex-Ohmeda anesthestia machines (General Electric, USA) went blank while in use. A burning smell was noticed in each case by the attending anesthesiologist. A portable monitor was hastily replaced in each case. Fortunately, no harm came to the patients.

The Aisys machines, 7 in total, were bought, from General Electric, USA, 2 1/2 years previously. Unfortunately, the supplied transformers had an incorrect rating. The 3 ampere fitted transformer was unable to power the larger 15-inch screen and burned out.
All 7 machines had the faulty 3 ampere transformers removed and replaced with new 5 ampere transformers. The machines have worked well ever since.

There are over 100 Aisys machines in South Africa that have not presented any problems. These machines use a smaller 12-inch screen that is powered by the patient monitor rack via the on-board UPS. battery supply back up. No external supply is used.

We bring these cases to your readers’ attention for the following reasons:

1. It is imperative that new machines coming from “overseas” are up to the electrical standards of the recipient country. Both the supplier and the local hospital bioengineering department have a responsibility regarding this. As far as we know this is the first documented case of this problem.
2. This may not be an isolated incident. It may have happened before and may not have been reported.

Alan Hold, MB, FFA
Durban, South Africa

John G Brock-Utne, MD, PhD
Stanford University Medical Center
Stanford, California, USA