SURGICAL patients are being put at risk of suffocation because of out-of-date equipment, according to a study by North-Eastern anaesthetists.

A research project involving a random sample of 51 hospitals in the UK found that about one in three anaesthetic machines did not have an anti-hypoxia device to safeguard against accidental suffocation.

Without such devices, there is a risk that patients may be suffocated by being given pure nitrous oxide (laughing gas), rather than a mixture of nitrous oxide, oxygen and other gases. Earlier this year, three-year-old Najiyah Hussein died after she was given nitrous oxide, instead of a mixture of gases, at Newham General Hospital, London.

The doctors estimate that it would cost £60m to replace all the obsolete machines, which tend to be more than ten years old.

The research was carried out by Dr Tim Meek and Dr David Saunders, both specialist registrars in anaesthesia at the Northern Schools of Anaesthesia, Newcastle.

Following the publication of their article in the British Medical Journal, the doctors have called on the Government to replace all anaesthesia machines which do not have the anti-hypoxia safeguard mechanism.

"Almost 30 per cent of the machines in our survey do not have an anti-hypoxia device. We have no reason to believe it is not the case for the places we didn't survey," said Dr Meek, who estimates that each new machine will cost about £20,000.

Checks by The Northern Echo found that many NHS trusts in the region have modernised anaesthetic machines, although some are still using older equipment.

Trusts in South Tees, North Tees and Hartlepool, and North Durham have anti-hypoxia devices fitted to all machines.