METHODS to prevent breathing tubes used in anaesthesia becoming blocked during operations were unveiled today.

Two years after an investigation was set up to look into the problem, a set of proposals has been published.

Chief Medical Officer Sir Liam Donaldson ordered the inquiry in July 2002 after 11 NHS cases of blocked anaesthetic tubing were reported, including a case at Sunderland Royal Hospital.

The best known incident involved nine-year-old Tony Clowes, who died while being prepared for an operation at Broomfield Hospital, Chelmsford, Essex, in July 2001.

He was to undergo surgery after trapping his finger in a bike chain and died because, unbeknown to doctors, a piece of connecting tube forming part of the anaesthetic apparatus had been blocked by a tiny plastic cap from another piece of surgical equipment.

Yesterday, the Expert Group, chaired by Professor Kent Woods, produced its findings.

Their recommendations included keeping small disposable plastic waste out of areas where patients are being anaesthetised and protecting vulnerable patient breathing circuit components by keeping them individually wrapped until use.

The group also advised raising awareness of potential safety issues by guidance, training and clear labelling of equipment and ensuring staff carry out routine checks.

Sir Liam Donaldson said: "Thankfully incidents where anaesthetic tubing becomes blocked are rare, but when it does happen the outcome can be very dangerous for the patient or even fatal.

He said the recommendations would significantly help improve patient safety.

The group looked into incidents of anaesthetic tube blockaging explored by police in an investigation called Operation Orcadian.

The police looked at incidents at two private hospitals and NHS hospitals in Basildon, Broomfield, Watford, Bournemouth, the Isle of Man, Sunderland, Bedford, Rotherham and Alder Hey, in Liverpool.