Entonox equipment as a potential source of cross-infection.

A survey of the hospitals with obstetric units within the Anglia and Oxford Region was performed to assess current practices regarding the cleaning of, and use of filters with, Entonox apparatus. The survey revealed that there was no consensus regarding the cleaning of the equipment and, in contrast to anaesthetic machines in which microbiological filters are recommended and in widespread use, only 10% of the hospitals surveyed were using such filters with the Entonox apparatus in their units. Cleaning procedures were changed in 75% of hospitals when dealing with known 'high-risk' patients, the remaining hospitals treating all patients as 'high-risk' or denied caring for such patients. All patients should be protected from potential cross-infection, and the recommendation that a microbiological filter should be placed between patients and the breathing system should be extended to Entonox equipment.